No abstract available
Τετάρτη 5 Σεπτεμβρίου 2018
Subcutaneous Mastectomy Improves Satisfaction with the Body and Psychosocial Function in Trans Men; Findings of a Cross-Sectional Study Using the BODY-Q Chest Module
Background: The effectiveness of gender confirming surgery is best evaluated on the basis of patient-reported outcomes such as appearance satisfaction and health-related quality of life. This is the first explorative study using the BODY-Q chest module, administered in trans men before and after mastectomy. Methods: Between October 2016 and May 2017, trans men were recruited to participate in a cross-sectional study. Data collection included standardized anamnesis and examination, screening questions on depression/anxiety, and seven BODY-Q scales, including new scales measuring satisfaction of the chest and nipples. Mean scores for pre- and post-operative participants were compared, and explorative regression analyses were conducted to identify factors associated with BODY-Q scores. Results: In total, 101 persons participated (89%; 50 pre-operative, 51 post-operative). Post-operative participants reported significantly higher (better) scores on the chest (M=67), nipple (M=58), body (M=58; t-tests, all p<.001 and psychological t-test p=".05)" scales compared with pre-operative patients. post-operative chest nipple mean scores did not differ significantly from a gynecomastia comparison whilst were less favorable on the psychosocial domains. pre-operatively associated objective breast size. lower planned revision surgery depressive symptoms as indicated by screening question. conclusions: present findings indicate that satisfaction differences in trans men undergoing mastectomy can be detected using body-q module. future prospective studies are needed to measure clinical change how this relates changes other aspects of health-related quality life. is an open-access article distributed under terms creative commons attribution-non commercial-no derivatives license where it permissible download share work provided properly cited. cannot changed any way or used commercially without permission journal. financial disclosure: anne klassen co-developer may receive revenues. remaining authors have no disclosures. acknowledgements: would like thank study participants developers well m marlon buncamper for their assistance data collection floyd timmermans editing final manuscript. corresponding author: tim c. van de grift vu university medical center p.o. box mb amsterdam netherlands society plastic surgeons>
Contralateral botulinum toxin improved functional recovery after tibial nerve repair in rats
Background: There is clinical and experimental evidence that botulinum toxin applied to the healthy side of patients with facial paralysis positively affects functional recovery of the paralyzed side. We created an experimental model to study the effects of botulinum toxin injection in the gastrocnemius muscle contralateral to the side of tibial nerve lesion/repair in rats. Methods: Fifty rats were allocated into five groups: I: control; II: tibial nerve section; III: tibial nerve section, immediate neurorrhaphy; IV: tibial nerve section, immediate neurorrhaphy and botulinum toxin injected into the contralateral gastrocnemius muscle; V: botulinum toxin injected into the gastrocnemius muscle, no surgery. Assessment tools included a walking track, electromyography, gastrocnemius muscle weight measurement, and histological analysis of the nerve. Results: Paralysis in group V was transient, with function returning to normal at 8 weeks. At 12 weeks, group V had lower latency levels. At week 12, group IV showed higher functional outcomes and amplitude levels than group III, and lower muscle atrophy on the side injected with botulinum toxin than group V. Conclusions: Transient paralysis of the contralateral gastrocnemius muscle by abobotulinumtoxinA improved functional recovery in rats that underwent section and repair of the tibial nerve. Presented at: American Society for Peripheral Nerve Annual Meeting (ASPN) 2017 in Waikoloa, Hawaii. Financial Disclosure Statement: The authors have no financial interest in any of the products, devices, or drugs mentioned in this manuscript. Corresponding author: Alessandra Grassi Salles, Rua Joaquim Floriano, 466, cj. 2102, São Paulo 04534-002, Brazil. Tel/Fax: 55-11-3078-1009, E-mail: agsalles30@gmail.com ©2018American Society of Plastic Surgeons
Clockwise and Counterclockwise Le Fort I Movements Influence Nasolabial Morphology Differently
Introduction: Le Fort I maxillary advancements are reported to affect nasal proportions. However, there is a no significant data on the three-dimensional nasal changes that occur with differential lateral plane adjustment (clockwise (CW) and counterclockwise (CCW) movements) during Le Fort I maxillary advancements. The purpose of this study was to analyze and compare nasolabial soft tissue changes after Le Fort I CW and CCW repositioning. Methods: Single-piece Le Fort I advancements were included in this morphometric study. A retrospective study of patients split into CW and CCW groups was performed. Pre- and postoperative 3D photographs (VECTRA, Canfield, Fairfield, NJ) were analyzed. Nasolabial anthropometric measurements were recorded (Mirror). Two observers verified the landmarks. Statistical analysis involved paired t test to compare pre- and postoperative nasolabial measurements. Results: Twenty-four patients were evaluated (12 per group), with 22 distinct nasolabial relationships measured. CCW showed a statistically significant increase in alar width (3.6mm, P
Neural Perforasomes of the Upper Extremity
Background: In the setting of the rapid advancement of integumentary vascular knowledge, we hypothesized that the extrinsic blood supply to the major peripheral nerves of the upper extremity could be categorized into discrete neural "perforasomes". Methods: Total limb perfusion of the arterial system was performed with gelatin-red lead oxide in cadaveric upper limbs. The perforating vessels to the radial, median and ulnar nerves were identified, confirmed with fluoroscopy and dissected. Distances to major anatomic landmarks of the upper extremity were measured. Additional cadaveric limbs' nerves were dissected and source arteries were selectively cannulated and injected to assess specific contribution to extrinsic nerve perfusion. The perfusion of each nerve was then calculated among all specimens. Results: The radial, median and ulnar nerve perforators were mapped. The corresponding neural perforasomes were mapped. The distal portions of the superficial radial nerve (SRN) and the posterior interosseous nerve (PIN) demonstrated a lack of staining. Similarly, at the carpal tunnel and at the proximal 25% of the median nerve (corresponding to the pronator teres), the nerve lacked vascular staining. At Guyon's canal and the flexor carpi ulnaris (FCU) the ulnar nerve demonstrated a lack of vascular staining. Conclusions: Peripheral nerves can be divided into neural perforasomes with limited overlap. The extrinsic perfusion of peripheral nerves is highly segmental. Absent staining within the nerves correspond to common sites of compression: carpal tunnel and pronator teres for the median nerve, supinator for the PIN, and Guyon's canal and the FCU for the ulnar nerve. None of the authors has a financial interest in any of the products, devices, or drugs mentioned in this manuscript. This research was supported by the American Foundation for Surgery of the Hand. This research was supported by the Piedmont Orthopaedic Foundation. This research has not been presented at any meetings. All named authors hereby declare that they have no conflicts of interest to disclose. This study is deemed exempt by the Duke University Institutional Review Board, Pro00075741. This research is supported by the Piedmont Orthopaedic Foundation. This research is supported by the American Foundation for Surgery of the Hand. Corresponding author: Steven Koehler, MD, Department of Orthopaedic Surgery, SUNY Downstate Medical Center, 450 Clarkson Ave, MSC 30, Brooklyn, NY 11203, Email: steven.koehler@downstate.edu ©2018American Society of Plastic Surgeons
Effects of Extracorporeal Shock Wave Therapyon Distraction Osteogenesis in Rat Mandible
Background: Distraction osteogenesis (DO) has widespread clinical use in the treatment of congenital and acquired craniofacial deformities. Nonetheless, during the prolonged consolidation period, the newly regenerated bone carries the risk of complications. One of the proposed methods to enhance bone healing and shorten the consolidation period is extracorporeal shock wave therapy (ESWT). In the field of orthopedics, ESWT has been shown to induce neovascularization and promote tissue regeneration. We investigated whether ESWT can accelerate bony consolidation and regeneration in distraction osteogenesis of the rat mandible and at which stage of DO it should be applied. Methods: 24 male Sprague Dawley rats were subjected to DO of the right mandible (latency period, 3 days; distraction period, 10 days, 0.5 mm/day). Experimental groups: group I (control) no ESWT: group II received ESWT (0.18 mJ/mm2) at the latency period; group III received ESWT (0.18 mJ/mm2) at the consolidation period. Explants were removed for evaluation following four weeks of consolidation. Results: Histological evaluation showed well developed cortical cortex and a higher degree of bone formation and mature bone in group III; µCT showed significantly increased bone mineral density, bone volume fraction and trabecular thickness; immunohistochemistry demonstrated significantly increased expression of Bone Morphogenetic Protein-2, Vascular Endothelial Growth Factor and PCNA. Conclusions: ESWT application at the consolidation period during DO in the rat mandible enhances bone formation, osteogenic and angiogenic growth factors, improves bone mechanical properties and accelerates bone mineralization. Financial Disclosure Statement: he authors declare that they have no conflict of interest. No funding was received for this article. None of the authors has a financial interest in any of the products, devices, or drugs mentioned in this manuscript. Corresponding author: Jiriys George Ginini, DMD, Rambam Health Care Campus, 8 Ha'Aliyah Street, Haifa 35254, Israel, Phone: +972-503330896, Fax: +972-7772557, Email: jiriysginini@technion.ac.il ©2018American Society of Plastic Surgeons
Obesity, Visceral Fat, and Hypertension-Related Complications
Metabolic Syndrome and Related Disorders, Ahead of Print.
Can the Plasma Concentration Ratio of Triglyceride/High-Density Lipoprotein Cholesterol Identify Individuals at High Risk of Cardiovascular Disease During 40-Year Follow-Up?
Metabolic Syndrome and Related Disorders, Ahead of Print.
Determining Factors of Arterial Stiffness in Subjects with Metabolic Syndrome
Metabolic Syndrome and Related Disorders, Ahead of Print.
Predictive Value of Lipid Accumulation Product, Fatty Liver Index, Visceral Adiposity Index for Metabolic Syndrome According to Menopausal Status
Metabolic Syndrome and Related Disorders, Ahead of Print.
Variation in the Plasma Levels of Polyunsaturated Fatty Acids in Control vis-à-vis Nonalcoholic Fatty Liver Disease Subjects and Its Possible Association with Gut Microbiome
Metabolic Syndrome and Related Disorders, Volume 16, Issue 7, Page 329-335, September 2018.
NASH in Nondiabetic Endocrine Disorders
Metabolic Syndrome and Related Disorders, Volume 16, Issue 7, Page 315-320, September 2018.
An unusual case of melanocytic matricoma in a young pregnant woman
Australasian Journal of Dermatology, EarlyView.
Updated Guidelines on Complex Regional Pain Syndrome in Adults
A multidisciplinary team representing 28 professional bodies has updated the guidelines for the management of Complex regional Pain Syndrome (CRPS), published by the Royal College of Physicians of England (RCP) 2018. The author represented the British Association of Plastic, Reconstructive and Aesthetic Surgeons in this process and is an author of the guidelines. This article summarises the updated guidelines and highlights aspects relevant to Plastic and Reconstructive Surgery.
Septocutaneous thoracodorsal artery perforator flaps: a retrospective cohort study
This study aimed to investigate the versatility of septocutaneous thoracodorsal artery perforator flaps in various areas in the body and the running pattern of septocutaneous perforators.
Determining Post-Operative Outcomes After Cleft Palate Repair: A Systematic Review and Meta Analysis
A lack of high level evidence exists on the outcomes of different cleft palate repair techniques. A critical appreciation for the complication rates of common repair techniques is paramount to optimize cleft palate care.
Selenium application alters soil cadmium bioavailability and reduces its accumulation in rice grown in Cd-contaminated soil
Abstract
Selenium (Se) alleviates cadmium (Cd) accumulation in several plants. Nevertheless, it is still unclear why it has such effect. Thus, this study aimed to investigate the effects of Se on soil Cd bioavailability, and Cd accumulation in flooded rice plants, and to determine the mechanisms underlying these effects. Concentration of Cd and Se in different rice tissues was determined along Cd and Se concentrations in the soil solution and soil Cd fractions. Results showed that exogenous selenite and selenate treatments significantly increased rice grain Se by 4.25- and 2.39-fold and decreased Cd by 36.5% and 25.3% relative to control treatment, respectively. The addition of Se to Cd-contaminated soil significantly decreased total Cd concentration in the soil solution by 11.2–13.0%, increased soil pH by 0.06–0.32 units, and enhanced soil Cd immobilization in relation to control. Exogenous Se also reduced diethylenetriaminepentaacetic acid-Cd, exchangeable, and residual Cd but increased the levels of Cd bound to carbonate and iron and manganese oxides. Thus, amending Cd-contaminated soil with Se may help decrease Cd content as well as increase Se levels in rice grain, as Se may mitigate Cd accumulation in rice plants by increasing soil pH, reducing Cd bioavailability, and inhibiting Cd translocation from roots to shoots.
A review on removal of siloxanes from biogas: with a special focus on volatile methylsiloxanes
Abstract
The occurrence of siloxanes is a major barrier to use of biogas as renewable energy source, and removal of siloxanes from biogas before combustion is needed. The siloxane can be transformed into silicon dioxide (SiO2) through the combustion process in engine, which will be deposited on the spark plug, cylinder, and impeller to form the silica layer, causing the wear and damage of the engine parts, and shorten the life of the engine and affect the utilization efficiency of the biogas. This paper reviewed some methods and technologies for siloxanes removal from biogas. There are three commercial available technologies to remove siloxanes: adsorption, absorption, and cryocondensation. Other newer technologies with better prospects for development also have made a research progress, including membrane, catalysts, biotrickling filters. This work introduces the source and characterization of siloxanes in biogas, reviews the scientific progress of siloxanes removal, and discusses the development direction and further research of removal siloxanes.
Estimation of formaldehyde occupational exposure limit based on genetic damage in some Iranian exposed workers using benchmark dose method
Abstract
The present study evaluated an occupational exposure level for formaldehyde employing benchmark dose (BMD) approach. Dose–response relationship was determined by utilizing cumulative occupational exposure dose and DNA damage. Based on this goal, outcome of comet assay for some Iranian exposed people in occupational exposure individuals was used. In order to assess formaldehyde exposure, 53 occupationally exposed individuals selected from four melamine tableware workshops and 34 unexposed subjects as a control group were examined. The occupational exposure dose was carried out according to the NIOSH-3500 method, and the DNA damage was obtained by employing comet assay in peripheral blood cells. EPA Benchmark Dose Software was employed for calculating BMD and BMDL. Cumulative exposure dose of formaldehyde was between of 2.4 and 1972 mg. According to the findings of the current study, the induction of DNA damage in the exposed persons was increased tail length and tail moment (p < 0.001), when compared to controls. Finally, an acceptable dose–response relationship was obtained in three-category information between formaldehyde cumulative exposure doses and genetic toxicity. BMDL was 0.034 mg/m3 (0.028 ppm), corresponding to genetic damage of peripheral blood cells. It can be concluded that the occupational permissible limit in Iranian people could be at levels lower than OSHA standards.
Evaluation of (–)-borneol derivatives against the Zika vector, Aedes aegypti and a non-target species, Artemia sp.
Abstract
Zika, dengue, and chikungunya are vector-borne diseases of pronounced concern transmitted by the mosquito Aedes aegypti Linn. (Diptera: Culicidae). The most important method to avoid outbreaks is to control mosquito spreading by the employment of insecticides and larvicides. Failure to control mosquito dispersal is mostly accounted to Ae. aegypti resistance to currently available larvicides and insecticides, encouraging the development of novel pesticides. In addition, the excessive use of larvicides poses serious threats to human health and the environment. Evaluation of natural products as larvicides in an attempt to overcome this situation is often found in the literature because products originated from nature are considered less toxic to non-target species and more eco-friendly. (–)-Borneol is a bicyclic monoterpene present in essential oils with moderate larvicidal activity. On account of these facts, it was of our interest to synthesize (–)-borneol ester derivatives aiming to study its structure-activity relationships against Ae. aegypti larvae. With the goal to estimate toxicity to a non-target species, evaluation of the lethal concentration 50% (LC50) on Artemia sp. (Artemiidae) and calculation of selectivity towards Ae. aegypti were carried out. The most potent derivative, (–)-Bornyl chloroacetate, exhibited the highest suitability index, demonstrating lower environmental toxicity than other borneol ester derivatives. A parabolic relationship between (–)-borneol esters larvicidal activity and partition coefficient (Log P) was achieved and a correlation equation obtained, validating the importance of lipophilicity to the larvicidal activity of these compounds.
The Histological Composition of Capsular Contracture Focussed on the Inner Layer of the Capsule: An Intra-Donor Baker-I Versus Baker-IV Comparison
Abstract
Background
Capsular contracture remains one of the major complications after breast implantation surgery. The extent of capsular contraction is scored using the Baker scale. The aim of this study was to compare intra-individual Baker-I with Baker-IV capsules, and in particular the prevalence and histological properties of the inner capsule layer.
Methods
Twenty capsules from ten patients were included after bilateral explantation surgery due to unilateral capsular contracture (Baker-IV) after cosmetic augmentation with textured implants. All capsules underwent (immune-)histochemical analysis: haematoxylin–eosin (morphology), CD68 (macrophages), cytokeratin (epithelial cells) and vimentin (fibroblasts), and were visually scored for cell density and the presence of an inner layer and measured for thickness.
Results
Baker-IV (n = 10) capsules were significantly thicker compared to Baker-I (n = 10) capsules (P = 0.004). An inner layer was present in 8 Baker-I capsules. All Baker-I capsules were vimentin and CD68-positive and cytokeratin-negative. Positive vimentin was seen throughout the inner layer, and CD-68 staining was observed adjacent to the intermediate capsule layer. In contrast, only 2 Baker-IV capsules had an inner layer, of which only 1 showed the same profile as Baker-I capsules (P = 0.016). No cytokeratin positivity was seen in any capsule. In Baker-IV capsules, outer layers showed more positivity for both vimentin and CD68.
Conclusion
The inner layer is morphologically consistent with synovial metaplasia and is more prevalent in healthy, uncontracted Baker-I capsules. This inverse relation between the presence of the inner layer and higher Baker classification or pathological contracture could indicate a protective role of the inner layer against capsular contracture formation.
Level of Evidence III
This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.
Updating Beliefs under Perceived Threat
Humans are better at integrating desirable information into their beliefs than undesirable information. This asymmetry poses an evolutionary puzzle, as it can lead to an underestimation of risk and thus failure to take precautionary action. Here, we suggest a mechanism that can speak to this conundrum. In particular, we show that the bias vanishes in response to perceived threat in the environment. We report that an improvement in participants' tendency to incorporate bad news into their beliefs is associated with physiological arousal in response to threat indexed by galvanic skin response and self-reported anxiety. This pattern of results was observed in a controlled laboratory setting (Experiment I), where perceived threat was manipulated, and in firefighters on duty (Experiment II), where it naturally varied. Such flexibility in how individuals integrate information may enhance the likelihood of responding to warnings with caution in environments rife with threat, while maintaining a positivity bias otherwise, a strategy that can increase well-being.
SIGNIFICANCE STATEMENT The human tendency to be overly optimistic has mystified scholars and lay people for decades: How could biased beliefs have been selected over unbiased beliefs? Scholars have suggested that although the optimism bias can lead to negative outcomes, including financial collapse and war, it can also facilitate health and productivity. Here, we demonstrate that a mechanism generating the optimism bias, namely asymmetric information integration, evaporates under threat. Such flexibility could result in enhanced caution in dangerous environments while supporting an optimism bias otherwise, potentially increasing well-being.
Experience-Dependent Development of Feature-Selective Synchronization in the Primary Visual Cortex
Early visual experience is essential for the maturation of visual functions in which the primary visual cortex plays crucial roles. The extraction of visual features based on response selectivity of individual neurons, a fundamental process in the cortex, is basically established by eye opening in rodents, suggesting that visual experience is required for the development of neural functions other than feature extraction. Here, we show that synchronized firing, which is important for visual information processing, occurs selectively in adjacent neurons sharing similar orientation or spatial frequency preferences in layers 2–4 (upper layer) of rat visual cortex. This feature-selective spike synchrony was rudimentary when the eyes opened and became prominent during the first few weeks after eye opening only in the presence of pattern vision. In contrast, synchronization in layers 5–6 (lower layer) was almost independent of orientation similarity and more weakly dependent on spatial frequency similarity compared with upper layer synchrony. Lower layer synchronization was strengthened during development after eye opening independently of visual experience as a whole. However, the feature selectivity of synchronization was regulated by visual inputs, whereas the inputs without contours were sufficient for this regulation. Therefore, we speculate that feature-selective synchronization in the upper layer may convey detailed information on visual objects to the higher-order cortex, whereas weakly feature-selective synchronization in the lower layer may covey rather rough visual information to the subcortical areas or higher-order cortex. A major role of visual experience may be to establish the specific neural circuits underlying highly feature-selective synchronization.
SIGNIFICANCE STATEMENT The neuronal mechanisms underlying experience-dependent improvement of visual functions still remain unresolved. In this study, we investigated whether early visual experience contributes to the development of synchronized neural firing in the primary visual cortex, which plays important roles in visual information processing. We found that synchronized firing depends more remarkably on the similarity of preferred visual stimuli in the upper than lower layer neurons. Pattern vision during development was required for the establishment of spike synchrony in the upper but not the lower layer. These findings provide a new view regarding the role of sensory experience in the functional development of the cortex and the differences in the modes of information processing in the upper and lower cortical layers.
S1PR3 Mediates Itch and Pain via Distinct TRP Channel-Dependent Pathways
Sphingosine 1-phosphate (S1P) is a bioactive signaling lipid associated with a variety of chronic pain and itch disorders. S1P signaling has been linked to cutaneous pain, but its role in itch has not yet been studied. Here, we find that S1P triggers itch and pain in male mice in a concentration-dependent manner, with low levels triggering acute itch alone and high levels triggering both pain and itch. Ca2+ imaging and electrophysiological experiments revealed that S1P signals via S1P receptor 3 (S1PR3) and TRPA1 in a subset of pruriceptors and via S1PR3 and TRPV1 in a subset of heat nociceptors. Consistent with these findings, S1P-evoked itch behaviors are selectively lost in mice lacking TRPA1, whereas S1P-evoked acute pain and heat hypersensitivity are selectively lost in mice lacking TRPV1. We conclude that S1P acts via different cellular and molecular mechanisms to trigger itch and pain. Our discovery elucidates the diverse roles that S1P signaling plays in somatosensation and provides insight into how itch and pain are discriminated in the periphery.
SIGNIFICANCE STATEMENT Itch and pain are major health problems with few effective treatments. Here, we show that the proinflammatory lipid sphingosine 1-phosphate (S1P) and its receptor, S1P receptor 3 (S1PR3), trigger itch and pain behaviors via distinct molecular and cellular mechanisms. Our results provide a detailed understanding of the roles that S1P and S1PR3 play in somatosensation, highlighting their potential as targets for analgesics and antipruritics, and provide new insight into the mechanistic underpinnings of itch versus pain discrimination in the periphery.
Central Amygdala Circuits Mediate Hyperalgesia in Alcohol-Dependent Rats
Alcohol withdrawal symptoms contribute to excessive alcohol drinking and relapse in alcohol-dependent individuals. Among these symptoms, alcohol withdrawal promotes hyperalgesia, but the neurological underpinnings of this phenomenon are not known. Chronic alcohol exposure alters cell signaling in the central nucleus of the amygdala (CeA), and the CeA is implicated in mediating alcohol dependence-related behaviors. The CeA projects to the periaqueductal gray (PAG), a region critical for descending pain modulation, and may have a role in alcohol withdrawal hyperalgesia. Here, we tested the roles of (1) CeA projections to PAG, (2) CeA melanocortin signaling, and (3) PAG μ-opioid receptor signaling in mediating thermal nociception and alcohol withdrawal hyperalgesia in male Wistar rats. Our results demonstrate that alcohol dependence reduces GABAergic signaling from CeA terminals onto PAG neurons and alters the CeA melanocortin system, that CeA-PAG projections and CeA melanocortin signaling mediate alcohol withdrawal hyperalgesia, and that μ-opioid receptors in PAG filter CeA effects on thermal nociception.
SIGNIFICANCE STATEMENT Hyperalgesia is commonly seen in individuals with alcohol use disorder during periods of withdrawal, but the neurological underpinnings behind this phenomenon are not completely understood. Here, we tested whether alcohol dependence exerts its influence on pain modulation via effects on the limbic system. Using behavioral, optogenetic, electrophysiological, and molecular biological approaches, we demonstrate that central nucleus of the amygdala (CeA) projections to periaqueductal gray mediate thermal hyperalgesia in alcohol-dependent and alcohol-naive rats. Using pharmacological approaches, we show that melanocortin receptor-4 signaling in CeA alters alcohol withdrawal hyperalgesia, but this effect is not mediated directly at synaptic inputs onto periaqueductal gray-projecting CeA neurons. Overall, our findings support a role for limbic influence over the descending pain pathway and identify a potential therapeutic target for treating hyperalgesia in individuals with alcohol use disorder .
Altered Gamma Oscillations during Motor Control in Children with Autism Spectrum Disorder
Autism is hypothesized to result in a cortical excitatory and inhibitory imbalance driven by inhibitory interneuron dysfunction, which is associated with the generation of gamma oscillations. On the other hand, impaired motor control has been widely reported in autism. However, no study has focused on the gamma oscillations during motor control in autism. In the present study, we investigated the motor-related gamma oscillations in autism using magnetoencephalography. Magnetoencephalographic signals were recorded from 14 right-handed human children with autism (5 female), aged 5–7 years, and age- and IQ-matched 15 typically developing children during a motor task using their right index finger. Consistent with previous studies, the autism group showed a significantly longer button response time and reduced amplitude of motor-evoked magnetic fields. We observed that the autism group exhibited a low peak frequency of motor-related gamma oscillations from the contralateral primary motor cortex, and these were associated with the severity of autism symptoms. The autism group showed a reduced power of motor-related gamma oscillations in the bilateral primary motor cortex. A linear discriminant analysis using the button response time and gamma oscillations showed a high classification performance (86.2% accuracy). The alterations of the gamma oscillations in autism might reflect the cortical excitatory and inhibitory imbalance. Our findings provide an important clue into the behavioral and neurophysiological alterations in autism and a potential biomarker for autism.
SIGNIFICANCE STATEMENT Currently, the diagnosis of autism has been based on behavioral assessments, and a crucial issue in the diagnosis of autism is to identify objective and quantifiable clinical biomarkers. A key hypothesis of the neurophysiology of autism is an excitatory and inhibitory imbalance in the brain, which is associated with the generation of gamma oscillations. On the other hand, motor deficits have also been widely reported in autism. This is the first study to demonstrate low motor performance and altered motor-related gamma oscillations in autism, reflecting a brain excitatory and inhibitory imbalance. Using these behavioral and neurophysiological parameters, we classified autism and control group with good accuracy. This work provides important information on behavioral and neurophysiological alterations in patients with autism.
Intracortical Microstimulation Modulates Cortical Induced Responses
Recent advances in cortical prosthetics relied on intracortical microstimulation (ICMS) to activate the cortical neural network and convey information to the brain. Here we show that activity elicited by low-current ICMS modulates induced cortical responses to a sensory stimulus in the primary auditory cortex (A1). A1 processes sensory stimuli in a stereotyped manner, encompassing two types of activity: evoked activity (phase-locked to the stimulus) and induced activity (non-phase-locked to the stimulus). Time-frequency analyses of extracellular potentials recorded from all layers and the surface of the auditory cortex of anesthetized guinea pigs of both sexes showed that ICMS during the processing of a transient acoustic stimulus differentially affected the evoked and induced response. Specifically, ICMS enhanced the long-latency-induced component, mimicking physiological gain increasing top-down feedback processes. Furthermore, the phase of the local field potential at the time of stimulation was predictive of the response amplitude for acoustic stimulation, ICMS, as well as combined acoustic and electric stimulation. Together, this was interpreted as a sign that the response to electrical stimulation was integrated into the ongoing cortical processes in contrast to substituting them. Consequently, ICMS modulated the cortical response to a sensory stimulus. We propose such targeted modulation of cortical activity (as opposed to a stimulation that substitutes the ongoing processes) as an alternative approach for cortical prostheses.
SIGNIFICANCE STATEMENT Intracortical microstimulation (ICMS) is commonly used to activate a specific subset of cortical neurons, without taking into account the ongoing activity at the time of stimulation. Here, we found that a low-current ICMS pulse modulated the way the auditory cortex processed a peripheral stimulus, by supra-additively combining the response to the ICMS with the cortical processing of the peripheral stimulus. This artificial modulation mimicked natural modulations of response magnitude such as attention or expectation. In contrast to what was implied in earlier studies, this shows that the response to electrical stimulation is not substituting ongoing cortical activity but is integrated into the natural processes.
Correlations Between Primary Motor Cortex Activity with Recent Past and Future Limb Motion During Unperturbed Reaching
Many studies highlight that human movements are highly successful yet display a surprising amount of variability from trial to trial. There is a consistent pattern of variability throughout movement: initial motor errors are corrected by the end of movement, suggesting the presence of a powerful online control process. Here, we analyze the trial-by-trial variability of goal-directed reaching in nonhuman primates (five male Rhesus monkeys) and demonstrate that they display a similar pattern of variability during reaching, including a strong negative correlation between initial and late hand motion. We then demonstrate that trial-to-trial neural variability of primary motor cortex (M1) is positively correlated with variability of future hand motion ( = ~160 ms) during reaching. Furthermore, the variability of M1 activity is also correlated with variability of past hand motion ( = ~90 ms), but in the opposite polarity (i.e., negative correlation). Partial correlation analysis demonstrated that M1 activity independently reflects the variability of both past and future hand motions. These findings provide support for the hypothesis that M1 activity is involved in online feedback control of motor actions.
SIGNIFICANCE STATEMENT Previous studies highlight that primary motor cortex (M1) rapidly responds to either visual or mechanical disturbances, suggesting its involvement in online feedback control. However, these studies required external disturbances to the motor system and it is not clear whether a similar feedback process addresses internal noise/errors generated by the motor system itself. Here, we introduce a novel analysis that evaluates how variations in the activity of M1 neurons covary with variations in hand motion on a trial-to-trial basis. The analyses demonstrate that M1 activity is correlated with hand motion in both the near future and the recent past, but with opposite polarity. These results suggest that M1 is involved in online feedback motor control to address errors/noise within the motor system.
Brain GABA Levels Are Associated with Inhibitory Control Deficits in Older Adults
Healthy aging is accompanied by motor inhibition deficits that involve a slower process of stopping a prepotent motor response (i.e., reactive inhibition) rather than a diminished ability to anticipate stopping (i.e., proactive inhibition). Some studies suggest that efficient motor inhibition is related to GABAergic function. Since age-related alterations in the GABA system have also been reported, motor inhibition impairments might be linked to GABAergic alterations in the cortico-subcortical network that mediates motor inhibition. Thirty young human adults (mean age, 23.2 years; age range, 18–34 years; 14 men) and 29 older human adults (mean age, 67.5 years; age range, 60–74 years; 13 men) performed a stop-signal task with varying levels of stop-signal probability. GABA+ levels were measured with magnetic resonance spectroscopy (MRS) in right inferior frontal cortex, pre-supplementary motor area (pre-SMA), left sensorimotor cortex, bilateral striatum, and occipital cortex. We found that reactive inhibition was worse in older adults compared with young adults, as indicated by longer stop-signal reaction times (SSRTs). No group differences in proactive inhibition were observed as both groups slowed down their response to a similar degree with increasing stop-signal probability. The MRS results showed that tissue-corrected GABA+ levels were on average lower in older as compared with young adults. Moreover, older adults with lower GABA+ levels in the pre-SMA were slower at stopping (i.e., had longer SSRTs). These findings suggest a role for the GABA system in reactive inhibition deficits.
SIGNIFICANCE STATEMENT Inhibitory control has been shown to diminish as a consequence of aging. We investigated whether the ability to stop a prepotent motor response and the ability to prepare to stop were related to GABA levels in different regions of the network that was previously identified to mediate inhibitory control. Overall, we found lower GABA levels in older adults compared with young adults. Importantly, those older adults who were slower at stopping had less GABA in the pre-supplementary motor area, a key node of the inhibitory control network. We propose that deficits in the stop process in part depend on the integrity of the GABA system.
The Rhesus Monkey Hippocampus Critically Contributes to Scene Memory Retrieval, But Not New Learning
Humans can recall a large number of memories years after the initial events. Patients with amnesia often have lesions to the hippocampus, but human lesions are imprecise, making it difficult to identify the anatomy underlying memory impairments. Rodent studies enable great precision in hippocampal manipulations, but not investigation of many interleaved memories. Thus it is not known how lesions restricted to the hippocampus affect the retrieval of multiple sequentially encoded memories. Furthermore, disagreement exists as to whether hippocampal inactivations lead to temporally graded or ungraded amnesia, which could be a consequence of differences between rodent and human studies. In the current study, rhesus monkeys of both sexes received either bilateral neurotoxic hippocampal lesions or remained unoperated controls and were tested on recognition and new learning of visual object-in-place scenes. Monkeys with hippocampal lesions were significantly impaired at remembering scenes that were encoded before the lesion. We did not observe any temporal gradient effect of the lesion on memory recognition, with recent and remote memories being equally affected by the lesion. Monkeys with hippocampal lesions showed no deficits in learning new scenes. Thus, the hippocampus, like other cortical regions, may be engaged in the acquisition and storage of new memories, but the role of the damaged hippocampus can be taken over by spared hippocampal tissue or extra-hippocampal regions following a lesion. These findings illustrate the utility of experimental paradigms for studying retrograde and anterograde amnesia that make use of the capacity of nonhuman primates to rapidly acquire many distinct visual memories.
SIGNIFICANCE STATEMENT Recalling old memories, creating new memories, and the process by which memories transition from temporary to permanent storage all may rely on the hippocampus. Whether the hippocampus is necessary for encoding and retrieval of multiple related visual memories in primates is not known. Monkeys that learned many visual memory problems before precise lesions of the hippocampus were impaired at recalling those memories after hippocampal damage regardless of when the memories were formed, but could learn new memory problems at a normal rate. This suggests the hippocampus is normally vital for retrieval of complex visual memories regardless of their age, and also points to the importance of investigating mechanisms by which memories may be acquired in the presence of hippocampal damage.
Language Exposure Relates to Structural Neural Connectivity in Childhood
Neuroscience research has elucidated broad relationships between socioeconomic status (SES) and young children's brain structure, but there is little mechanistic knowledge about specific environmental factors that are associated with specific variation in brain structure. One environmental factor, early language exposure, predicts children's linguistic and cognitive skills and later academic achievement, but how language exposure relates to neuroanatomy is unknown. By measuring the real-world language exposure of young children (ages 4–6 years, 27 male/13 female), we confirmed the preregistered hypothesis that greater adult-child conversational experience, independent of SES and the sheer amount of adult speech, is related to stronger, more coherent white matter connectivity in the left arcuate and superior longitudinal fasciculi on average, and specifically near their anterior termination at Broca's area in left inferior frontal cortex. Fractional anisotropy of significant tract subregions mediated the relationship between conversational turns and children's language skills and indicated a neuroanatomical mechanism underlying the SES "language gap." Post hoc whole-brain analyses revealed that language exposure was not related to any other white matter tracts, indicating the specificity of this relationship. Results suggest that the development of dorsal language tracts is environmentally influenced, specifically by early, dialogic interaction. Furthermore, these findings raise the possibility that early intervention programs aiming to ameliorate disadvantages in development due to family SES may focus on increasing children's conversational exposure to capitalize on the early neural plasticity underlying cognitive development.
SIGNIFICANCE STATEMENT Over the last decade, cognitive neuroscience has highlighted the detrimental impact of disadvantaged backgrounds on young children's brain structure. However, to intervene effectively, we must know which proximal aspects of the environmental aspects are most strongly related to neural development. The present study finds that young children's real-world language exposure, and specifically the amount of adult-child conversation, correlates with the strength of connectivity in the left hemisphere white matter pathway connecting two canonical language regions, independent of socioeconomic status and the sheer volume of adult speech. These findings suggest that early intervention programs aiming to close the achievement gap may focus on increasing children's conversational exposure to capitalize on the early neural plasticity underlying cognitive development.
Parietal Representations of Stimulus Features Are Amplified during Memory Retrieval and Flexibly Aligned with Top-Down Goals
In studies of human episodic memory, the phenomenon of reactivation has traditionally been observed in regions of occipitotemporal cortex (OTC) involved in visual perception. However, reactivation also occurs in lateral parietal cortex (LPC), and recent evidence suggests that stimulus-specific reactivation may be stronger in LPC than in OTC. These observations raise important questions about the nature of memory representations in LPC and their relationship to representations in OTC. Here, we report two fMRI experiments that quantified stimulus feature information (color and object category) within LPC and OTC, separately during perception and memory retrieval, in male and female human subjects. Across both experiments, we observed a clear dissociation between OTC and LPC: while feature information in OTC was relatively stronger during perception than memory, feature information in LPC was relatively stronger during memory than perception. Thus, while OTC and LPC represented common stimulus features in our experiments, they preferentially represented this information during different stages. In LPC, this bias toward mnemonic information co-occurred with stimulus-level reinstatement during memory retrieval. In Experiment 2, we considered whether mnemonic feature information in LPC was flexibly and dynamically shaped by top-down retrieval goals. Indeed, we found that dorsal LPC preferentially represented retrieved feature information that addressed the current goal. In contrast, ventral LPC represented retrieved features independent of the current goal. Collectively, these findings provide insight into the nature and significance of mnemonic representations in LPC and constitute an important bridge between putative mnemonic and control functions of parietal cortex.
SIGNIFICANCE STATEMENT When humans remember an event from the past, patterns of sensory activity that were present during the initial event are thought to be reactivated. Here, we investigated the role of lateral parietal cortex (LPC), a high-level region of association cortex, in representing prior visual experiences. We find that LPC contained stronger information about stimulus features during memory retrieval than during perception. We also found that current task goals influenced the strength of stimulus feature information in LPC during memory. These findings suggest that, in addition to early sensory areas, high-level areas of cortex, such as LPC, represent visual information during memory retrieval, and that these areas may play a special role in flexibly aligning memories with current goals.
Activity and Connectivity Differences Underlying Inhibitory Control Across the Adult Life Span
Inhibitory control requires precise regulation of activity and connectivity within multiple brain networks. Previous studies have typically evaluated age-related changes in regional activity or changes in interregional interactions. Instead, we test the hypothesis that activity and connectivity make distinct, complementary contributions to performance across the life span and the maintenance of successful inhibitory control systems. A representative sample of healthy human adults in a large, population-based life span cohort performed an integrated Stop-Signal (SS)/No-Go task during functional magnetic resonance imaging (n = 119; age range, 18–88 years). Individual differences in inhibitory control were measured in terms of the SS reaction time (SSRT), using the blocked integration method. Linear models and independent components analysis revealed that individual differences in SSRT correlated with both activity and connectivity in a distributed inhibition network, comprising prefrontal, premotor, and motor regions. Importantly, this pattern was moderated by age, such that the association between inhibitory control and connectivity, but not activity, differed with age. Multivariate statistics and out-of-sample validation tests of multifactorial functional organization identified differential roles of activity and connectivity in determining an individual's SSRT across the life span. We propose that age-related differences in adaptive cognitive control are best characterized by the joint consideration of multifocal activity and connectivity within distributed brain networks. These insights may facilitate the development of new strategies to support cognitive ability in old age.
SIGNIFICANCE STATEMENT The preservation of cognitive and motor control is crucial for maintaining well being across the life span. We show that such control is determined by both activity and connectivity within distributed brain networks. In a large, population-based cohort, we used a novel whole-brain multivariate approach to estimate the functional components of inhibitory control, in terms of their activity and connectivity. Both activity and connectivity in the inhibition network changed with age. But only the association between performance and connectivity, not activity, differed with age. The results suggest that adaptive control is best characterized by the joint consideration of multifocal activity and connectivity. These insights may facilitate the development of new strategies to maintain cognitive ability across the life span in health and disease.
Evaluating the Columnar Stability of Acoustic Processing in the Human Auditory Cortex
Using ultra-high field fMRI, we explored the cortical depth-dependent stability of acoustic feature preference in human auditory cortex. We collected responses from human auditory cortex (subjects from either sex) to a large number of natural sounds at submillimeter spatial resolution, and observed that these responses were well explained by a model that assumes neuronal population tuning to frequency-specific spectrotemporal modulations. We observed a relatively stable (columnar) tuning to frequency and temporal modulations. However, spectral modulation tuning was variable throughout the cortical depth. This difference in columnar stability between feature maps could not be explained by a difference in map smoothness, as the preference along the cortical sheet varied in a similar manner for the different feature maps. Furthermore, tuning to all three features was more columnar in primary than nonprimary auditory cortex. The observed overall lack of overlapping columnar regions across acoustic feature maps suggests, especially for primary auditory cortex, a coding strategy in which across cortical depths tuning to some features is kept stable, whereas tuning to other features systematically varies.
SIGNIFICANCE STATEMENT In the human auditory cortex, sound aspects are processed in large-scale maps. Invasive animal studies show that an additional processing organization may be implemented orthogonal to the cortical sheet (i.e., in the columnar direction), but it is unknown whether observed organizational principles apply to the human auditory cortex. Combining ultra-high field fMRI with natural sounds, we explore the columnar organization of various sound aspects. Our results suggest that the human auditory cortex contains a modular coding strategy, where, for each module, several sound aspects act as an anchor along which computations are performed while the processing of another sound aspect undergoes a transformation. This strategy may serve to optimally represent the content of our complex acoustic natural environment.
A Transient Developmental Window of Fast-Spiking Interneuron Dysfunction in a Mouse Model of Dravet Syndrome
Dravet syndrome is a severe, childhood-onset epilepsy largely due to heterozygous loss-of-function mutation of the gene SCN1A, which encodes the type 1 neuronal voltage-gated sodium (Na+) channel α subunit Nav1.1. Prior studies in mouse models of Dravet syndrome (Scn1a+/– mice) indicate that, in cerebral cortex, Nav1.1 is predominantly expressed in GABAergic interneurons, in particular in parvalbumin-positive fast-spiking basket cell interneurons (PVINs). This has led to a model of Dravet syndrome pathogenesis in which Nav1.1 mutation leads to preferential dysfunction of interneurons, decreased synaptic inhibition, hyperexcitability, and epilepsy. However, such studies have been implemented at early developmental time points. Here, we performed electrophysiological recordings in acute brain slices prepared from male and female Scn1a+/– mice as well as age-matched wild-type littermate controls and found that, later in development, the excitability of PVINs had normalized. Analysis of action potential waveforms indirectly suggests a reorganization of axonal Na+ channels in PVINs from Scn1a+/– mice, a finding supported by immunohistochemical data showing elongation of the axon initial segment. Our results imply that transient impairment of action potential generation by PVINs may contribute to the initial appearance of epilepsy, but is not the mechanism of ongoing, chronic epilepsy in Dravet syndrome.
SIGNIFICANCE STATEMENT Dravet syndrome is characterized by normal early development, temperature-sensitive seizures in infancy, progression to treatment-resistant epilepsy, developmental delay, autism, and sudden unexplained death due to mutation in SCN1A encoding the Na+ channel subunit Nav1.1. Prior work has revealed a preferential impact of Nav1.1 loss on the function of GABAergic inhibitory interneurons. However, such data derive exclusively from recordings of neurons in young Scn1a+/– mice. Here, we show that impaired action potential generation observed in parvalbumin-positive fast-spiking interneurons (PVINs) in Scn1a+/– mice during early development has normalized by postnatal day 35. This work suggests that a transient impairment of PVINs contributes to epilepsy onset, but is not the mechanism of ongoing, chronic epilepsy in Dravet syndrome.
Treatment of Refractory Granuloma Faciale With Intralesional Rituximab
This case series describes the results of intralesional rituximab treatment in men with granuloma faciale.
Necrotic Plaque on the Distal Nose With Diffuse Crateriform Nodules
A man in his 30s presented with a progressively necrotic plaque on the nose, scattered nodules on the extremities, and erythematous papules on the arms and legs. What is your diagnosis?
Complementary and Alternative Medicine Therapies for Psoriasis
This systematic review summarizes the evidence on the efficacy of the most studied complementary and alternative medicine therapies for treatment of plaque psoriasis and discusses those treatments with the most robust available evidence.
Predictions, Surprises, and the Future of the Dermatology Workforce
With the debut of managed care in the 1980s, experts in the physician workforce portended an impending surplus of specialist physicians, including dermatologists. Despite these dire predictions, a dermatology workforce shortage was identified in the late 1990s, with an associated geographical imbalance. Since then, the overall shortage has only modestly abated, so it would not be surprising to find that an urban-rural workforce maldistribution has persisted. Indeed, in this issue of JAMA Dermatology, Feng and colleagues present physician data from 1995 to 2013 demonstrating that the maldistribution of dermatologists may well have worsened. They show an overall increase in density of dermatologists but a widening gap between metropolitan vs nonmetropolitan and rural communities. Additionally, the ratio of younger compared with older dermatologists (using a cutoff of age 55 years, the approximate mean physician age in the United States) increased in urban settings and simultaneously decreased in rural settings, a distribution that may cause this gap to grow.
Comparison of Dermatologist Density Between Urban and Rural Counties in the United States
This study analyzes county-level data from nationwide US data to compare dermatologist density between urban and rural areas.
Laser Treatment Performed Decades After Napalm Burns
This case report describes the use of laser treatment beginning in 2015 to treat napalm burns sustained by the famous Vietnamese "Napalm Girl" in 1972.
Detection of Glycemia and Osmolarity Changes Using Eye Examinations
Metabolic Syndrome and Related Disorders, Ahead of Print.
Efficacy of breast reconstruction with fat grafting: A systematic review and meta-analysis
Publication date: Available online 4 September 2018
Source: Journal of Plastic, Reconstructive & Aesthetic Surgery
Author(s): Mikkel Herly, Mathias Ørholt, Andreas Larsen, Christian B. Pipper, Rikke Bredgaard, Christina S. Gramkow, Adam J. Katz, Krzysztof T. Drzewiecki, Peter V. Vester-Glowinski
Summary
Background
Breast reconstruction with fat grafting is a new alternative to prosthetic implants and flaps for women with breast cancer. In this study, we investigate the efficacy of fat grafting for breast reconstruction in a meta-analysis.
Methods
The study followed the PRISMA and MOOSE guidelines for systematic reviews and meta-analyses. Studies were included if the patients underwent complete breast reconstruction with fat grafting as the only treatment modality. The number of fat grafting treatments needed to complete a breast reconstruction was modeled in a meta-analysis for five treatment categories: modified radical mastectomy, skin-sparing mastectomy and breast-conserving surgery; the two mastectomy groups were subdivided into non-irradiated and irradiated.
Results
Twenty-one studies were included in the meta-analysis. The studies comprised 1011 breast reconstructions from 834 patients. The estimated numbers of treatments to complete a reconstruction were 2.84-4.66 in the mastectomy groups and 1.72 in the breast-conserving surgery group. The number of fat grafting sessions needed to complete a breast reconstruction was significantly higher for the irradiated patients than for the non-irradiated patients (p < 0.05). There was no significant difference in the number of fat grafting sessions needed to complete a breast reconstruction after a modified radical mastectomy versus a skin-sparing mastectomy.
Conclusions
This study provides an evidence-based foundation for several practical issues related to breast reconstruction with fat grafting. The analysis showed that radiotherapy is the most important factor associated with the number of treatment sessions needed to complete a breast reconstruction and with the rate of complications.
Comparison of piezosurgery, percutaneous and endonasal continuous osteotomy techniques on a caprine skull model
Publication date: Available online 4 September 2018
Source: Journal of Plastic, Reconstructive & Aesthetic Surgery
Author(s): Sevgi Kurt Yazar, Merdan Serin, Ibrahim Taskin Rakici, Selami Serhat Sirvan, Fatih Irmak, Memet Yazar
Abstract
Background
Osteotomy is a crucial step in rhinoplasty which can have a significant impact on the outcome. In addition to previous percutaneous (external perforating) and endonasal (internal) approaches, piezosurgery has been used in rhinoplasty practice since 2007. This experimental model was planned to compare the three osteotomy techniques.
Materials and Methods
This study was performed on a caprine skull osteotomy model. Three groups were created from 12 animals which consist of endonasal continuous, external perforating and piezosurgery groups. All the groups were evaluated for the bone gaps, comminuted fractures as well as nasal mucosa damage.
Results
There were no comminuted fractures and mucosal defects in any of the samples in the piezo osteotomy group. The average amount of bone gap at the osteotomy site and the nasal mucosa damage was lower in the piezo group compared with the other groups. The time required for the osteotomy was shorter in the endonasal group, similar in external and piezo group.
Conclusion
New techniques are constantly being developed to achieve better results in rhinoplasty. As a natural consequence to technological developments new devices are being introduced to rhinoplasty practice. Piezo is one of such devices. We have found that piezo osteotomy has resulted in lower amounts nasal mucosal damage and comminuted fractures. We believe that piezo can be safely be used in rhinoplasty practice until newer and more reliable technologies are being developed.
A SIMPLE METHOD FOR LYMPHEDEMA SELF-MEASUREMENT USING THE ZOZOSUIT BODYSUIT
Publication date: Available online 4 September 2018
Source: Journal of Plastic, Reconstructive & Aesthetic Surgery
Author(s): Chihena H. Banda, Ryohei Ishiura, Minami Fujita, Kohei Mitsui, Mitsunaga Narushima
Cartilage sparing surgery for melanoma of the external ear
Publication date: Available online 4 September 2018
Source: Journal of Plastic, Reconstructive & Aesthetic Surgery
Author(s): Conrad Harrison, Cian Wade, Matthew Potter, Oliver Cassell
Summary
Background
The excision of melanoma of the external ear poses a challenge to surgeons, who must achieve adequate oncological control while minimising impact on form and function. Cartilage preserving surgery is an attractive option as it leaves behind a scaffold for immediate reconstruction with a variety of techniques including full thickness skin grafts (FTSGs) and local flaps. This manuscript will review the literature comparing cartilage sparing surgery with composite excision of skin and cartilage for the treatment of auricular melanoma. We report the results of a 17-year experience of using both techniques, together with sentinel node biopsy at our centre.
Methods
A structured review of MEDLINE and EMBASE was conducted evaluating all studies reporting local recurrence or survival rates for melanoma of the external ear treated with cartilage preserving surgery. A retrospective review of all patients undergoing wide local excision (WLE) and sentinel lymph node biopsy (SLNB) for auricular melanoma at our centre between 2000-2017 was performed.
Results
Of 40 patients identified, 29 underwent cartilage preserving surgery with no local recurrences or evidence of perichondral involvement. There was one local recurrence out of 11 patients who had had cartilage excised. There were no significant differences in recurrence rates or melanoma-specific survival when comparing cartilage preserving and cartilage sacrificing surgery. Our results are supported by the literature review which suggests cartilage sparing surgery is gaining acceptance as safe practice.
sOPTIMISING EXPOSURE OF THE CORONOID PROCESS DURING LENGTHENING TEMPORALIS MYOPLASTY FOR FACIAL REANIMATION
Publication date: Available online 4 September 2018
Source: Journal of Plastic, Reconstructive & Aesthetic Surgery
Author(s): Hodgins N, Ahmed OA, Ragbir M, Bashir MA
Shear wave elastography in the diagnosis of the ulnar tunnel syndrome.
Publication date: Available online 4 September 2018
Source: Journal of Plastic, Reconstructive & Aesthetic Surgery
Author(s): Ł Paluch, BH Noszczyk, J Walecki, K Osiak, M Kiciński, P Pietruski
Summary
An interesting alternative to traditional diagnostic techniques of the upper extremity nerve entrapments might be provided by an ultrasound elastography that started to gain attention in recent research. The aim of this preliminary study was to verify if quantitative analysis of ulnar nerve stiffness with shear-wave elastography can be used to diagnose the ulnar tunnel syndrome, an ulnar nerve neuropathy at the Guyon's canal. The study included 46 patients (39 women) and 39 healthy controls (34 women). All diagnoses in patients and controls were confirmed with nerve conduction studies. Measurements of nerve stiffness were taken at three levels: in Guyon's canal (G) and at distal (DF) and mid-forearm (MF). Additionally, ulnar nerve cross-sectional area at the canal's level was determined by means of ultrasonography. Patients with the ulnar tunnel syndrome presented with significantly greater nerve stiffness than the controls (mean, 99.41 kPa vs. 49.08 kPa, P <0.001). No significant intergroup differences were found in the nerve elasticity at DF and MF (P <0.836 and P < 0.881, respectively). Ulnar nerve stiffness value of 80 kPa, and G:DF and G:MF ratios equal to 1.5 provided 100% sensitivity, specificity, positive and negative predictive value in the detection of the syndrome. Mean nerve cross-sectional area in the Guyon's canal was significantly greater in patients than in the controls (4.63 mm2, range, 2-7 mm2 vs. 3.23 mm2, range, 2-5 mm2, P <0.001). In conclusion, we believe that shear-wave elastography has a potential to become a useful adjunct diagnostic test for the ulnar tunnel syndrome.
Utilization of Installation Wound Vacuum Device for Breast Implant Salvage: Approach and Results
Publication date: Available online 4 September 2018
Source: Journal of Plastic, Reconstructive & Aesthetic Surgery
Author(s): Risal Djohan, Isis Scomaco, Eliana Duraes, Rebecca Knackstedt
Readability and quality of breast reduction on-line resources
Publication date: Available online 4 September 2018
Source: Journal of Plastic, Reconstructive & Aesthetic Surgery
Author(s): AM Kennedy, C Davidson, E Cronin, R Caulfield
Summary
Many patients are now using the Internet as a resource for health-related information. It is recommended that the readability of patient education materials should be equal to or less than an 11-13-year-old reading level.
The aim of this study was to evaluate the readability and quality of websites related to breast reduction.
The largest internet search engine was queried for 'breast reduction'. 112 articles from the ten most popular websites were downloaded for analysis. Results from the private cosmetic industry were excluded. Articles were assessed for readability using 10 validated readability tools and for quality using the DISCERN instrument.
The mean reading level of all websites was that of of a 16-17 year-old. The BAAPS, BAPRAS and NHS websites all exceeded the recommended reading level (all greater than a 14-year old reading level).
The highest quality website was NHS Choices with a DISCERN score of 75. The American Board of Cosmetic Surgery website received the lowest quality score of 36.
There was a statistically significant strong negative correlation between the DISCERN score and reading age, implying that higher quality websites are more likely to achieve the recommended 11-13-year old reading level.
Online patient resources about breast reduction are uniformly above the recommended target readability level and are likely too difficult for many patients to understand. The results of this study could enable surgeons to recommend sources of information for patients considering breast reduction as well as helping patients to evaluate the quality of medical information available on the Internet.
Magnetic biochar-based manganese oxide composite for enhanced fluoroquinolone antibiotic removal from water
Abstract
Magnetic biochar-based manganese oxide composite (MMB) and raw biochar (BC) were synthesized via pyrolysis at a temperature of 500 °C under anoxic conditions of potato stems and leaves, characterized, and successfully used for the removal of norfloxacin (NOR), ciprofloxacin (CIP), and enrofloxacin (ENR) as representative compounds of fluoroquinolone antibiotics (FQs). Characterization results suggested that Fe3O4 and MnOx are the dominant crystals in MMB. MMB possessed large surface area and pore volume than BC. Batch adsorption experiments showed that the maximum adsorption abilities of MMB for norfloxacin (NOR), ciprofloxacin (CIP), and enrofloxacin (ENR) were 6.94, 8.37, and 7.19 mg g−1. In comparison to BC, the adsorption abilities of MMB increased 1.2, 1.5, and 1.6 times for NOR, CIP, and ENR, respectively. The pseudo-second-order kinetic model and the Langmuir model correlated satisfactorily to the experimental data. Thermodynamic studies revealed that the adsorption processes were spontaneous and endothermic. The adsorption capacity of MMB decreased with increasing solution pH (between 3.0 and 10.0) and increasing ionic strength (0.001–0.1). The MMB with high FQ removal efficiency, easy separation, and desirable regeneration ability may have promising environmental applications for the removal of fluoroquinolone antibiotics from water environment.
The effect of cellulose production waste and municipal sewage sludge on biomass and heavy metal uptake by a plant mixture
Abstract
Environmental management of cellulose production waste and municipal sewage sludge appears to be substantiated due to various physicochemical properties of these wastes. The aim of the conducted research was to determine the effect of cellulose production waste and sewage sludge on yielding and heavy metal uptake by a plant mixture. The research was conducted under field experiment conditions, determining the fertilizer value of these wastes in the environmental aspect. The research was carried out in the years 2013–2016. Species composition of the plant mixture was adjusted to habitat conditions. It was established that, as compared with the cellulose production waste, the municipal sewage sludge used in the experiment had a higher content of macroelements. The content of heavy metals in the studied waste did not exceed the limits that condition their use in agriculture and reclamation. Applying only the cellulose production waste did not significantly decrease the yield of the plants. Municipal sewage sludge showed the highest yield-forming effect. Mixing the above-mentioned wastes and their application to soil had a significant effect on the increase in the plant mixture yield. The waste applied to soil also increased the content of Cr, Cd, Pb, Cu, and Zn in the plant mix. The level of heavy metal content in the plant mix did not exclude this biomass from being used for fodder or reclamation purposes. The cellulose production waste and municipal sewage sludge increased the heavy metal uptake by the plant mixture. The plant biomass extracted heavy metals from the sewage sludge more intensively than from the cellulose production waste. Among the analyzed heavy metals, the highest phytoremediation was recorded for Ni (30%), followed by Cd (20%), Cr (15%), Pb (10%), and the lowest for Cu (9%) and Zn (8%). Application of the cellulose production waste and sewage sludge to soil also increased the content of the studied heavy metals in soil. However, it did not cause deterioration of soil quality standards. Heterogeneity in the chemical composition of the wastes confirms that each batch intended to be used for environmental management should be subjected to chemical control.
Physiological characterization of common bean ( Phaseolus vulgaris L.) under abiotic stresses for breeding purposes
Abstract
In the Brazilian wet and dry seasons, common beans (Phaseolus vulgaris L.) are grown under rainfed conditions with unexpected episodes of drought and high temperatures. The objective of this study was to evaluate the physiological mechanisms associated with drought adaptation traits in landraces and line/cultivars of beans from the Andean and Mesoamerican gene pools. Twenty-five genotypes, contrasting in terms of drought tolerance, were evaluated in a phenotyping platform under irrigated and rainfed conditions. Agronomic and physiological parameters such as grain yield, shoot structures, gas exchange, water potential, and osmotic adjustment were evaluated. The stress intensity was estimated to be 0.57, and the grain yield reduction ranged from 22 to 89%. Seven accessions, representative of the Andean and Mesoamerican germplasm (CF 200012, CF 240056, CF 250002, CF 900004, CNF 4497, CNF 7382, and SEA 5), presented superior performance in grain yield with and without stresses. The physiological responses under abiotic stresses were highly variable among the genotypes, and two Mesoamerican accessions (CF 200012 and SEA 5) showed more favorable adaptive responses. As the main secondary physiological traits, gas exchange and osmotic adjustment should be evaluated together with the grain yield to increase the selection efficiency of abiotic stresses-tolerant common bean lines.
Highly efficient treatment of real benzene dye intermediate wastewater by simple limestone and lime neutralization-coagulation with improved Fenton oxidation
Abstract
Multistage Fenton oxidation is a favored method for the treatment of benzene dye intermediate (BDI) wastewater, but the pH adjustments required after each stage of the Fenton process with a simple way is still a challenge. Limestone pretreatment and lime neutralization-coagulation were used to solve the problem in multistage Fenton process. First, we determined the optimal conditions of Fenton oxidation using the Box-Behnken response surface method. Limestone pretreatment before the multistage Fenton process allowed for simultaneous pH adjustment and 14.15% COD removal. Most notably, the lime cream neutralization-coagulation process effectively adjusted the pH after each stage of the Fenton process. The optimum CaO particle size, lime mass fraction, mixing time, and stirring speed were determined by orthogonal tests. COD removal (89.23%) was obtained when lime cream neutralization-coagulation was applied to the three-staged Fenton process, while only 58.57% COD removal was obtained by the unadjusted single-staged Fenton process. The COD and wastewater color were reduced from 10,600 mg/L and 12,200 multiples to 495 mg/L and 20 multiples, respectively, using the adjusted process. This improved method provides a promising cost-effective way to efficiently treat real BDI wastewater.
Effect of distillery spentwash fertigation on crop growth, yield, and accumulation of potentially toxic elements in rice
Abstract
The safe disposal of industrial effluents always remained a challenging process because of their high level of nutrients, toxic elements, and salts. A pot experiment was conducted to investigate the effects of various concentrations (5%, 10%, 15%, and 20%) of sugar industry effluent spentwash (SW) fertigated with tab water (TW), on soil properties, crop growth, physiological parameters, yield components, and accumulation of potentially toxic elements (PTEs) in rice (Oryza sativa L.) grains and straw. The results showed that soil physico-chemical properties were modified with rise in SW concentration. Application of 5% SW significantly enhanced the plant growth, and yield components. Photosynthesis rate, transpiration rate, and stomatal conductance were significantly higher under 5% SW concentration in comparison with control. However, SW concentrations of > 5% showed inhibitory effects for all growth, physiological, and yield components. Accumulation of PTEs showed increasing trend with rise in SW concentration. However, under 5% SW concentration, all the PTEs in rice grain and straw were within the permissible limits (PLs) recommended by FAO/WHO and no health hazards were detected by health risk assessment. Based on the study results, 5% SW fertigation with TW can be applied as fertilizer for enhancing the growth and productivity of rice.
Graphical abstract
Effects of Reslizumab on Asthma Outcomes in a Subgroup of Eosinophilic Asthma Patients with Self-Reported Chronic Rhinosinusitis with Nasal Polyps
Publication date: Available online 5 September 2018
Source: The Journal of Allergy and Clinical Immunology: In Practice
Author(s): Steven F. Weinstein, Rohit K. Katial, Philip Bardin, Stephanie Korn, Mirna McDonald, Margaret Garin, Eric D. Bateman, Flavia C.L. Hoyte, Matthew Germinaro
ABSTRACT
BACKGROUND
An estimated 7% of patients with asthma have chronic rhinosinusitis with nasal polyps (CRSwNP) and over 80% have at least some radiographic evidence of sinonasal inflammation. Aspirin sensitivity is strongly associated with elevated blood eosinophil levels and increased asthma severity. Intravenous (IV) reslizumab has been shown to improve asthma control in patients with nasal polyps.
OBJECTIVE
These post-hoc analyses of pooled data from two BREATH phase 3 clinical trials, studies 1 and 2 (NCT01287039 and NCT01285323), examined asthma-related outcomes in patients with comorbid, self-reported CRSwNP with and without aspirin sensitivity.
METHODS
Patients aged 12–75 years with elevated blood eosinophils (≥400 cells/μL) and inadequately controlled asthma were randomized to receive placebo or reslizumab (3 mg/kg IV) every 4 weeks for 52 weeks. Patients continued their background asthma maintenance therapy during the study. Information regarding the presence of CRSwNP was obtained through patient-reported medical history.
RESULTS
Add-on reslizumab treatment reduced the frequency of clinical asthma exacerbations (CAE) by 83% vs placebo among patients with CRSwNP. Among patients with and without aspirin sensitivity, reductions of 79% and 84%, respectively, were observed. Patients with CRSwNP (with and without aspirin sensitivity) treated with reslizumab add-on therapy also had significant improvements in lung function, as measured by FEV1, compared with placebo. Among patients with CRSwNP, reslizumab was also associated with improvements in patient-reported asthma control and asthma quality of life.
CONCLUSION
Patients with eosinophilic asthma and self-reported CRSwNP, with and without aspirin sensitivity, are highly responsive to treatment with reslizumab for asthma-related outcomes. These findings suggest that prospective investigation of reslizumab in this patient population is warranted.
Staphylococcus aureus nasal colonization and asthma in adults: systematic review and meta-analysis
Publication date: Available online 5 September 2018
Source: The Journal of Allergy and Clinical Immunology: In Practice
Author(s): Young-Chan Kim, Ha-Kyeong Won, Ji Won Lee, Kyoung-Hee Sohn, Min-Hye Kim, Tae-Bum Kim, Yoon-Seok Chang, Byung-Jae Lee, Sang-Heon Cho, Claus Bachert, Woo-Jung Song
Abstract
Background
Staphylococcus aureus (SA) is a frequent colonizer in human and it is known to be associated with chronic allergic diseases including asthma. Recent individual studies suggested that nasal SA colonization may be positively associated with asthma.
Objective
To examine relationships between nasal SA colonization and asthma prevalence and activity in adults.
Methods
Electronic databases were searched for studies published until June 2018. Studies that reported nasal SA colonization prevalence and asthma outcome (prevalence and disease activity) in general adult populations or chronic rhinosinusitis (CRS) patients were included. Random effects meta-analyses were performed to calculate pooled odds ratio (OR) of the relationships. Subgroup analysis was conducted for the presence of nasal polyps within CRS populations.
Results
A total of 21 cross-sectional studies were identified, and the data from 16 studies using culture methods for SA detection were meta-analyzed (5 general population-based studies and 11 CRS patient studies). In studies of general populations, nasal SA colonization had significant relationships with asthma prevalence (OR 1.19; 95% confidence interval 1.06-1.34; I2 = 1%). In CRS patient studies, positive associations were also found but had a considerable heterogeneity (OR 1.87; 95% CI 1.18-2.97; I2 = 72%). However, the results were comparable between CRS with and without nasal polyps.
Conclusions
This study demonstrated modest but significant relationships between nasal SA colonization and asthma, supporting potential roles of SA in adult asthma patients. Further longitudinal cohort and intervention studies are warranted to identify host determinants and to clarify causality of the relationships.
Patient versus allergy specialist interpretation of a negative workup for suspected iodinated contrast media allergy
Publication date: Available online 5 September 2018
Source: The Journal of Allergy and Clinical Immunology: In Practice
Author(s): Rik Schrijvers, Christine Breynaert, Jean-Luc Bourrain, Pascal Demoly, Anca Mirela Chiriac
Children with neutrophil-predominant severe asthma have pro-inflammatory neutrophils with enhanced survival and impaired clearance
Publication date: Available online 5 September 2018
Source: The Journal of Allergy and Clinical Immunology: In Practice
Author(s): Jocelyn R. Grunwell, Susan T. Stephenson, Rabindra Tirouvanziam, Lou Ann S. Brown, Milton R. Brown, Anne M. Fitzpatrick
Background
Airway neutrophils are abundant in some children with severe asthma, but their functions are poorly understood.
Objective
We hypothesized that the inflammatory airway environment of children with neutrophil-predominant severe asthma promotes neutrophil survival and disrupts neutrophil-associated innate immune defenses.
Methods
Sixty seven children with severe asthma refractory to high-dose inhaled corticosteroid (ICS) treatment undergoing bronchoscopy with bronchoalveolar lavage (BAL) for clinical indications were stratified into neutrophil "high" versus "low" groups based on BAL differential counts. Neutrophil activation markers, functional assays and phenotyping studies were performed as well as airway macrophage functional assays. Results were compared to those from children with moderate asthma treated with ICS.
Results
Children with neutrophil-predominant severe asthma had increased markers of neutrophil activation/degranulation and a greater magnitude of airway pro-inflammatory cytokine and chemokine release. Primary neutrophils exposed to BAL of these children exhibited greater phagocytic capability and greater neutrophil extracellular trap formation, but a more impaired respiratory burst. Despite greater abundance of airway TGF-β1, the neutrophils were not more apoptotic. Instead, neutrophils had a highly pro-inflammatory phenotype associated with a number of surface markers that regulate neutrophil activation, recruitment/migration and granule release. Airway macrophages from children with neutrophil-predominant severe asthma were also more pro-inflammatory with impaired phagocytosis and increased apoptosis.
Conclusions
Children with neutrophil-predominant severe asthma have pro-inflammatory neutrophils with enhanced survival. Airway macrophages are also pro-inflammatory and dysfunctional and may contribute to global innate immune impairment. Therapies that target neutrophils and related inflammation may be warranted in this subset of children.
Bronchial Thermoplasty: A Decade of Experience: State of The Art
Publication date: Available online 5 September 2018
Source: The Journal of Allergy and Clinical Immunology: In Practice
Author(s): Laren D. Tan, Ken Y. Yoneda, Samuel Louie, D.Kyle Hogarth, Mario Castro
Abstract:
Bronchial thermoplasty (BT) delivers targeted radiofrequency energy to bronchial airway walls and results in the partial ablation of the airway smooth muscle that is responsible for bronchoconstriction. It is approved for the treatment of severe persistent asthma. Multiple, large clinical trials including a recent "real-world" study demonstrate significant improvements in asthma-related quality of life, reduction in asthma exacerbations, emergency department visits and hospitalizations after BT that is sustained out to 5 years. In this article, we review the state of the art of BT treatment in severe persistent asthma and share a decade of BT research and clinical experience. We share our personal experience and introduce the three "I"s (identification, implementation and intense follow up) that we believe promote successful patient outcomes and help build a successful BT program.
Fatal asthma: an audit of 30 million patient-years of health plan membership from 2007 to 2015
Publication date: Available online 5 September 2018
Source: The Journal of Allergy and Clinical Immunology: In Practice
Author(s): Eric Macy, Janis F. Yao, Wansu Chen
Abstract
Background
Without accurate data on deaths directly caused by asthma, prevention will be difficult.
Objective
Determine how often asthma could be confirmed as a proximal cause of death in a large well-defined population with active health plan membership and no acute barriers to medical care.
Methods
All deaths occurring in active Kaiser Permanente Southern California health plan members between 2007 and 2015 were identified. Asthma-coded deaths were manually audited for cause. Healthcare and asthma medication use in the 6 months prior to death were determined.
Results
There were 248 [0.80 per 100,000 patient-years] un-audited asthma-coded deaths. There were only 63 (26.5%) [0.20 per 100,000 patient-years] asthma-confirmed deaths. Individuals with asthma-confirmed deaths were younger, less likely to have ever smoked, and had fewer emergency visits in the 6 months prior to death compared to those with asthma excluded. Individuals with asthma-confirmed deaths used preventative inhalers at very low rates. We unexpectedly found that ever inclusion in the 2016 National Committee for Quality Assurance health effectiveness data and information set (HEDIS) for persistent asthma was associated with a higher risk of all cause early death. Individuals with asthma-confirmed deaths were also unlikely to be in the HEDIS asthma dataset in the year they died, thus not targeted for outreach.
Conclusions
Audit-confirmed fatal asthma is more likely to occur in younger, non-smoking, individuals, using very low rates of preventive inhalers. This will be a very difficult group to prospectively identify and manage effectively. Further research into the reasons for early death after HEDIS asthma dataset inclusion is warranted.
Profile of the skin microbiota in a healthy Chinese population
The Journal of Dermatology, EarlyView.
Photochemical oxidation of di- n -butyl phthalate in atmospheric hydrometeors by hydroxyl radicals from nitrous acid
Abstract
The photochemical oxidation of di-n-butyl phthalate (DBP) by •OH radicals from nitrous acid (HONO) in atmospheric hydrometeors was explored by two techniques, steady-state irradiation, and laser flash photolysis (LFP). The effects of atmospheric liquid parameters on DBP transformation were systematically evaluated, showing that DBP does not react with HONO directly and •OH-initiated reactions are crucial steps for consumption and transformation of DBP. Two reaction channels are operative: •OH addition and hydrogen atom abstraction. The overall rate constant for the reaction of DBP with •OH is 5.7 × 109 M−1 s−1, and its specific rate constant for addition is 3.7 × 109 M−1 s−1 determined by using laser flash photolysis technique. Comparing the individual reaction rate constant for aromatic ring addition with the total rate constant, the majority of the •OH radicals (about 65%) attack the aromatic ring. The major transformation products were identified by GC-MS, and the trends of their yields derived from both ring addition and H-abstraction with time are discussed. These results provide important insights into the photochemical transformation of DBP in atmospheric hydrometeors and contribute to atmospheric aerosol chemistry.
Levels and sources of organic compounds in fine ambient aerosols over National Capital Region of India
Abstract
The study presents the spatial and temporal variation of fine ambient aerosols (PM2.5) over National Capital Region (NCR), India, during January to June 2016. The investigation includes three sampling sites, one in Delhi and two in the adjoining states of Delhi (Uttar Pradesh and Haryana), across NCR, India. The average PM2.5 concentration was highest for Delhi (128.5 ± 51.5 μg m−3) and lowest for Mahendragarh, Haryana (74.5 ± 28.7 μg m−3), during the study period. Seasonal variation was similar for all the sites with highest concentration during winter and lowest in summer. PM2.5 samples were analysed for organic compounds using gas chromatograph (GC). The concentration of three organic compound classes, n-alkanes (C11–C35), polycyclic aromatic hydrocarbons (PAHs), and phthalates, present in PM2.5 samples has been reported. Diagnostic ratios for n-alkanes demonstrated that biogenic emissions were dominant over Mahendragarh while major contributions were observed from petrogenic emissions over Delhi and Modinagar, Uttar Pradesh. Molecular diagnostic ratios were calculated to distinguish between different sources of PAHs, which revealed that the fossil fuel combustion (diesel and gasoline emissions), traffic emissions, and biomass burning are the major source contributors. Health risk associated with human exposure of phthalates and PAHs was also assessed as daily intake (DI, ng kg−1 day−1) and lung cancer risk, respectively. Backward trajectory analysis explained the local, regional, and long-range transport routes of PM2.5 for all sites. Principal component analysis (PCA) results summarized that the vehicular emissions, biomass burning, and plastic burning were the major sources of the PAHs and phthalates over the sampling sites.
Earthworms as plug flow reactors: a first-order kinetic study on the gut of the vermicomposting earthworm Eudrilus eugeniae
Abstract
Earthworms are commonly referred as environmental engineers and their guts are often compared with chemical reactors. However, modeling experiments to substantiate it are lacking. The aim of this study was to use established reactor models, particularly PFR, on the gut of the vermicomposting earthworm Eudrilus eugeniae to understand more on its digestion. To achieve the objective, a mathematical model based on first-order kinetics was framed and used to determine the pattern of digestion rates of nutrient indicators, namely total carbon (%), total nitrogen (%), C/N ratio, 13C (‰), and 15N (‰) at five intersections (pre-intestine, foregut, midgut A, midgut B, and hindgut) along the gut of E. eugeniae. The experimental results revealed that the concentrations of TC, TN, 13C, and 15N decreased during gut transit, whereas C/N ratio increased. The first-order model demonstrated that all the nutrients exhibit a linear pattern of digestion during gut transit, which supports the PFR model. On this basis, the present study concludes that the gut of E. eugeniae functions as PFR.
Diagnostics of Pleiotropy in Mendelian Randomization Studies: Global and Individual Tests for Direct Effects
Abstract
Diagnosing pleiotropy is critical for assessing the validity of Mendelian randomization (MR) analyses. The popular MR-Egger method evaluates whether there is evidence of bias-generating pleiotropy among a set of candidate genetic instrumental variables. In this article, we propose GLIDE, GLobal and Individual tests for Direct Effects, a statistical method to systematically evaluate pleiotropy among the set of genetic variants, e.g., single nucleotide polymorphisms (SNPs), used for MR. As a global test, simulation experiments suggest that GLIDE is nearly uniformly more powerful than the MR-Egger method. As a sensitivity analysis, GLIDE is capable of detecting outliers in individual variant-level pleiotropy, in order to obtain a refined set of genetic instrumental variables. We used GLIDE to analyze both body-mass index and height for risk of colorectal cancer in the Genetics and Epidemiology of Colorectal Cancer Consortium. Among the body mass index associated SNPs and the height associated SNPs, several individual variants showed evidence of pleiotropy. Removal of these potentially pleiotropic SNPs resulted in attenuation of respective estimates of the causal effects. In summary, the proposed GLIDE method is useful for sensitivity analyses and improves the validity of MR.Promise and Pitfalls of the Sibling Comparison Design in Studies of Optimal Birth Spacing
Abstract
Numerous observational studies have shown that infants born after short interpregnancy intervals (the interval between birth and subsequent conception) are more likely to experience adverse perinatal outcomes than infants born following longer intervals. Yet, it remains controversial whether the link between short interpregnancy interval and adverse outcomes is causal, or confounded by factors such as low socio-economic position, inadequate access to healthcare, and unintended pregnancy. Sibling comparison studies, which use a woman as her own control by comparing exposure and outcome status of her different pregnancies (i.e., comparing sibling offspring), have gained popularity as a strategy to reduce confounding by these difficult-to-measure factors that are nevertheless relatively stable within women. A variant of the design, used by Regan et al. in this issue (Am J Epidemiol 2018;XX:XXX-XXX), is a maternally-matched design based on a single interpregnancy interval per woman. Using real and simulated data, we highlight underappreciated shortcomings of these designs that may limit the validity of study findings. In particular, we illustrate how the single-interval variant appears to derive estimates from comparisons between different mothers, not within mothers. Future studies of optimal birth spacing using sibling comparison designs should examine in detail the potential consequences of these methodological limitations.Detecting individual and global horizontal pleiotropy in Mendelian randomization: a job for the humble heterogeneity statistic?
Abstract
Mendelian randomization (MR) is gaining in recognition and popularity as a method for strengthening causal inference in epidemiology by utilizing genetic variants as instrumental variables. Concurrently with the explosion in empirical MR studies there has been the steady production of new approaches for MR-analysis. The recently proposed Global and Individual tests of Direct Effects (GLIDE) approach fits into a family of methods that aim to detect horizontal pleiotropy - at the individual SNP level and at the global level - and to adjust the analysis by removing outlying SNPs. The purpose of this commentary is to explain how existing methods can (and indeed are) being used to detect pleiotropy at the individual and global level, although not explicitly using this terminology. By doing so, we will show that the true comparator for GLIDE is not MR-Egger regression (as the authors of the GLIDE approach claim), but rather the humble heterogeneity statistic.A Population-based Matched Sibling Analysis Estimating the Association between First Interpregnancy Interval and Birth Outcomes
Abstract
The association between a single interpregnancy interval (IPI) on birth outcomes has not yet been explored using matched methods. We modelled the odds of preterm birth, small-for-gestational age and low birthweight in a second, liveborn infant in a cohort of 192,041 sibling pairs born in Western Australia between 1980 and 2010. The association between IPI and birth outcomes was estimated from the interaction between birth order and IPI (with 18–23 months as the reference category), using conditional logistic regression. Matched analysis showed the odds of preterm birth were higher for siblings born following an IPI <6 month (adjusted Interaction Odds Ratio [IOR]: 1.22; 95% CI: 1.06, 1.38) compared with 18–23 month IPI. There were no significant differences for IPI <6 months for other outcomes (small-for-gestational age or low birthweight). This is the first study to use matched analyses to investigate the association between a single IPI on birth outcomes. IPI <6 months were associated with increased odds of preterm birth in secondborn infants, although the association is likely smaller than previously estimated by unmatched studies.Estimating the Short-term Effects of the Earned Income Tax Credit on Child Health
Abstract
The earned income tax credit (EITC) is the largest U.S. poverty alleviation program, yet few studies examine its effects on the health of recipients' children. We employed quasi-experimental techniques to test the hypothesis that EITC refund receipt is associated with short-term improvements in child health. The data set included children surveyed in the Third National Health and Nutrition Examination Survey (N=7,444). We employed a difference-in-differences approach, exploiting the seasonal nature of EITC refund receipt. We compared children of EITC-eligible families interviewed immediately after refund receipt (February-April) with those interviewed during other months (May-January), differencing out seasonal variation among non-EITC-eligible families. We examined outcomes that were likely to be affected immediately after refund receipt, including general health, nutrition, metabolic and inflammatory biomarkers, and test scores. There were improvements in physician-reported overall health after refund receipt, but no changes in infection, serum metabolic or inflammatory markers, or test scores, and contradictory findings for food insufficiency. In summary, EITC refunds are not strongly associated with most short-term health outcomes among recipients' children, although numerous previous studies have demonstrated impacts on longer-term outcomes. This highlights the importance of examining the effects of public policies on beneficiaries and their children using varying study designs.Effects of Multiple Forms of Information Bias on Estimated Prevalence of Suicide Attempts by Sexual Orientation: An Application of a Bayesian Misclassification Correction Method to Data from a Systematic Review
Abstract
Multiple epidemiologic studies demonstrate a disparity in suicide risk between sexual minority (lesbian, gay, bisexual) and heterosexual populations; however, both 'exposure' (sexual minority status) and outcome (suicide attempts) may be affected by information bias related to errors in self-reporting. We therefore applied a Bayesian misclassification correction method to account for possible information biases. A systematic literature search identified studies of lifetime suicide attempts in sexual minority and heterosexual adults, and frequentist meta-analysis was used to generate unadjusted estimates of relative risk. A Bayesian model accounting for prior information about sensitivity and specificity of exposure and outcome measures was used to adjust for misclassification biases. In unadjusted frequentist analysis, the relative risk of lifetime suicide attempt comparing sexual minority to heterosexual groups was 3.38 (95% confidence interval: 2.65, 4.32). In Bayesian re-analysis, the estimated prevalence was slightly reduced in heterosexual adults and increased in sexual minority adults, yielding a relative risk of 4.67 (95% credible interval: 3.94, 5.73). The disparity in lifetime suicide attempts between sexual minority and heterosexual adults is greater than previously estimated, when accounting for multiple forms of information bias. Additional research on the impact of information bias in studies of sexual minority health should be pursued.
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