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Τετάρτη 16 Μαρτίου 2022

The time course of different neuromuscular adaptations to short-term downhill running training and their specific relationships with strength gains

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Abstract

Purpose

Due to its eccentric nature, downhill running (DR) training has been suggested to promote strength gains through neuromuscular adaptations. However, it is unknown whether short-term chronic DR can elicit such adaptations.

Methods

Twelve untrained, young, healthy adults (5 women, 7 men) took part in 4 weeks' DR, comprising 10 sessions, with running speed equivalent to 60–65% maximal oxygen uptake ( \(\dot{V}\) O2max, assessed at weeks 0 and 4). Isometric and isokinetic knee-extensor maximal voluntary torque (MVT), vastus lateralis (VL) muscle morphology/architecture (anatomical cross-sectional area, ACSA; physiological CSA, PCSA; volume; fascicle length, Lf; pennation angle, PA) and neuromuscular activation (VL EMG) were assessed at weeks 0, 2 and 4.

Results

MVT increased by 9.7–15.2% after 4 weeks (p < 0.01). VL EMG during isometric MVT increased by 35.6 ± 46.1% after 4 weeks (p < 0.05) and correlated with changes in isometric MVT after 2 weeks (r = 0.86, p = 0.001). VL ACSA (+2.9 ± 2.7% and +7.1 ± 3.5%) and volume (+2.5 ± 2.5% and +6.6 ± 3.2%) increased after 2 and 4 weeks, respectively (p < 0.05). PCSA (+3.8 ± 3.3%), PA (+5.8 ± 3.8%) and Lf (+2.7 ± 2.2%) increased after 4 weeks (p < 0.01). Changes in VL volume (r = 0.67, p = 0.03) and PCSA (r = 0.71, p = 0.01) correlated with changes in concentric MVT from 2 to 4 weeks. \(\dot{V}\) O2max (49.4 ± 6.2 vs. 49.7 ± 6.3 mL·kg−1·min−1) did not change after 4 weeks (p = 0.73).

Conclusion

Just 4 weeks' moderate-intensity DR promoted neuromuscular adaptations in young, healthy adults, typically observed after high-intensity eccentric resistance training. Neural adaptations appeared to contribute to most of the strength gains at 2 and 4 weeks, while muscle hypertrophy seemed to contribute to MVT changes from 2 to 4 weeks only.

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The effects of eccentric hamstring exercise training in young female handball players

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Abstract

Purpose

The multidimensional role of hamstring muscle group strength in athletic performance and injury prevention is well documented, and nordic hamstring exercise (NHE) is a popular method for the development of hamstring strength. Our aim was to examine the EMG characteristics of the eccentric NHE as well as the effects of long-term eccentric NHE training on muscle strength and vertical jump performance in 10- to 11-year-old female handball players.

Methods

Players from the same handball team were randomly assigned to an eccentric NHE training (13 players) or a control group (10 players). Both groups continued their regular handball training routine, but the NHE group performed additional eccentric NHE exercises once or twice a week, with progressively increasing volume, over 20 weeks. To test training effects, countermovement jump (CMJ) height, eccentric hamstring impulse, peak torque, and angle of peak torque were evaluated before, during and after the training period. In the pre-exercise test, EMG activity of the medial and lateral hamstring muscle was also assessed during NHE.

Results

Hamstring activities ranged between 98 and 129%. Lateral hamstring activity was greater than medial only in the right leg during NHE. Eccentric hamstring impulse improved in both legs at 10 weeks in both groups. Then, at 20 weeks, it remained unchanged in the NHE but decreased in controls. A similar adaptation was seen in eccentric hamstring torque, without change in the optimum knee angle. CMJ height improved only in the NHE.

Conclusion

It is concluded that NHE activates the hamstring musculature effectively, and a favourable mechanical adaptation to long-term NHE exercise in girls can be triggered as early as 11 years of age.

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Enhancement of radiation response of breast cancer cells through the incorporation of Bi2S3 nanorods

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Abstract

The aim of this work was to develop nanomaterials that can be used as sensitizers in radiotherapy treatment. The synthesis of bismuth sulfide (Bi2S3) particles with nanometer size by the hot injection method was studied as well as their behavior when coated with a biocompatible agent. The hot injection method allowed us to synthesize Bi2S3 nanorods measuring in average 4.2 ± 1.4 nm in width and 27.5 ± 16.3 nm in length. Moreover, to improve their biocompatibility, these nanorods were coated with polyvinylpyrrolidone with the purpose of studying the behavior of nanorods in the bloodstream. The results indicated that the suspensions were more stable when the media had protein components which may facilitate the blood circulation of the particles. The toxicity of the nanorods and their radiosensitization potential were evaluated and determined in breast cancer cells (MCF7). These results show that the synthesized nanorods did not evidence cytotoxicity up to a concentration of 2500 μg/mL, over 72 h of incubation. On the other hand, the sensitivity of MCF7 cells with and without nanorods in the culture medium, afterward irradiating them with a dose of 2 Gy 60Co gamma radiation source, showed a 38% increase in cell death when compared to cells that were only irradiated. Our results show that Bi2S3 nanorods are very promising as anticancer agents improving the efficiency of radiotherapy.

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Gastric duplication cyst: a challenging EUS differential diagnosis between subepithelial gastric lesion and exophytic pancreatic cystic neoplasm—a case report and a literature review

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Abstract

Gastric duplication cysts are rare congenital malformation with a potential neoplastic progression and they may represent a challenge in differential diagnosis with exophytic pancreatic cyst neoplasm. We describe a case of a 38-year old man, complaining of recurrent epigastric pain due to a large abdominal mass, referred to our Hospital for EUS evaluation. Differential diagnosis was between gastric duplication cyst and exophytic pancreatic cyst because of FNA pointed out amylase 1280 UI/L and CEA 593.33 ng/mL. Despite antibiotic prophylaxis, an overinfection of the lesion occurred after the FNA, likely due to the technical failure to drain the cyst completely. Afterwards, the patient was referred to surgery and the pathologist confirmed the diagnosis of gastric duplication cyst. In this setting, EUS procedure has gained a leading play, complementary to traditional imaging tests, although its role has been not yet standardized in the reported literature. Here , we describe and discuss our demanding case, and we propose an algorithm to simplify and standardize the diagnostic workup.

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Real-time eye state recognition using dual convolutional neural network ensemble

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Abstract

Automatic recognition of the eye states is essential for diverse computer vision applications related to drowsiness detection, facial emotion recognition (FER), human–computer interaction (HCI), etc. Existing solutions for eye state detection are either parameter intensive or suffer from a low recognition rate. This paper presents the design and implementation of a vision-based system for real-time eye state recognition on a resource-constrained embedded platform to tackle these issues. The designed system uses an ensemble of two lightweight convolutional neural networks (CNN), each trained to extract relevant information from the eye patches. We adopted transfer-learning-based fine-tuning to overcome the over-fitting issues when training the CNNs on small sample eye state datasets. Once trained, these CNNs are integrated and jointly fine-tuned to achieve enhanced performance. Experimental results manifest the effectiveness of the proposed eye state recognizer that is robust and computationally efficient. On the ZJU dataset, the proposed DCNNE model delivered the state-of-the-art recognition accuracy of 97.99% and surpassed the prior best recognition accuracy of 97.20% by 0.79%. The designed model also achieved competitive results on the CEW and MRL datasets. Finally, the designed CNNs are optimized and ported on two different embedded platforms for real-world applications with real-time performance. The complete system runs at 62 frames per second (FPS) on an Nvidia Xavier device and 11 FPS on a low-cost Intel NCS2 embedded platform using a frame size of 640 \(\times\) 480 pixels resolution.

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The role of DHCR24 in the pathogenesis of AD: re-cognition of the relationship between cholesterol and AD pathogenesis

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Abstract

Previous studies show that 3β-hydroxysterol-Δ24 reductase (DHCR24) has a remarked decline in the brain of AD patients. In brain cholesterol synthetic metabolism, DHCR24 is known as the heavily key synthetase in cholesterol synthesis. Moreover, mutations of DHCR24 gene result in inhibition of the enzymatic activity of DHCR24, causing brain cholesterol deficiency and desmosterol accumulation. Furthermore, in vitro studies also demonstrated that DHCR24 knockdown lead to the inhibition of cholesterol synthesis, and the decrease of plasma membrane cholesterol and intracellular cholesterol level. Obviously, DHCR24 could play a crucial role in maintaining cholesterol homeostasis via the control of cholesterol synthesis. Over the past two decades, accumulating data suggests that DHCR24 activity is downregulated by major risk factors for AD, suggesting a potential link between DHCR24 downregulation and AD pathogenesis. Thus, the brain cholesterol loss seems to be indu ced by the major risk factors for AD, suggesting a possible causative link between brain cholesterol loss and AD. According to previous data and our study, we further found that the reduced cholesterol level in plasma membrane and intracellular compartments by the deficiency of DHCR24 activity obviously was involved in β-amyloid generation, tau hyperphosphorylation, apoptosis. Importantly, increasing evidences reveal that the brain cholesterol loss and lipid raft disorganization are obviously linked to neuropathological impairments which are associated with AD pathogenesis. Therefore, based on previous data and research on DHCR24, we suppose that the brain cholesterol deficiency/loss might be involved in the pathogenesis of AD.

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Colocalization of Coronary Plaque with Wall Shear Stress in Myocardial Bridge Patients

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Abstract

Purpose

Patients with myocardial bridges (MBs) have a higher prevalence of atherosclerosis. Wall shear stress (WSS) has previously been correlated with plaque in coronary artery disease patients, but such correlations have not been investigated in symptomatic MB patients. The aim of this paper was to use a multi-scale computational fluid dynamics (CFD) framework to simulate hemodynamics in MB patient, and investigate the co-localization of WSS and plaque.

Methods

We identified N = 10 patients from a previously reported cohort of 50 symptomatic MB patients, all of whom had plaque in the proximal vessel. Dynamic 3D models were reconstructed from coronary computed tomography angiography (CCTA), intravascular ultrasound (IVUS) and catheter angiograms. CFD simulations were performed to compute WSS proximal to, within and distal to the MB. Plaque was quantified from IVUS images in 2 mm segments and registered to CFD model. Plaque area was compared to absolute and patient-normalized WSS.

Results

WSS was lower in the proximal segment compared to the bridge segment (6.1 ± 2.9 vs. 16.0 ± 7.1 dynes/cm2, p value < 0.01). Plaque area and plaque burden measured from IVUS peaked at 1–3 cm proximal to the MB entrance, coinciding with the first diagonal branch. Normalized WSS showed a statistically significant moderate correlation with plaque area (r = 0.41, p < 0.01).

Conclusion

WSS may be obtained non-invasively in MB patients and provides a surrogate marker of plaque area. Using CFD, it may be possible to non-invasively assess the extent of plaque area, and identify patients who could benefit from frequent monitoring or medical management.

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Laser‐Assisted Sialolithotripsy: A Correlation of Objective and Subjective Outcomes

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Objective

To analyze the long-term symptomatic results of laser-assisted sialolithotripsy (LAS) in cases of obstructive sialolithiasis and correlate with objective criteria using diagnostic sialendoscopy (DS) as a method of examination.

Methods

This is a retrospective study comprising 50 consecutive patients who underwent holmium-YAG LAS and completed follow-up of at least 6 months. Symptom scoring and endoscopic scoring were done at 6 weeks and 6 months intervals for further study purposes.

Results

At the end of 6 weeks post-LAS, 70% patients were asymptomatic (A-sym) and only 30% had residual symptoms (Sym). However, obstructed duct (OB-duct) was observed on endoscopic scoring in 88% due to stenosis, residual stones, or both stenosis and residual stones. The obstructed ducts were treated in outpatient clinic and followed up over time, leading to 98% of patients being in A-sym group at the end of study period of 6 months. At the end of study, 82% of patients had clear duct (CL-duct).

Conclusion

Holmium LAS is a viable option for the management of intermediate-sized stones. LAS if used judiciously, and in properly selected cases, has high rate of stone fragmentation and symptom resolution. A vigilant postoperative protocol taking into account residual mealtime symptoms and altered salivary characteristics combined with early DS can help identify and treat patients with residual stone fragments and ductal stenosis.

Level of Evidence

3 Laryngoscope, 2022

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Τρίτη 15 Μαρτίου 2022

Bilateral asymmetry in bullfrog testes and fat bodies: correlations with steroidogenic activity, mast cells number and structural proteins

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Via histochem

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Acta Histochem. 2022 Mar 11;124(3):151873. doi: 10.1016/j.acthis.2022.151873. Online ahead of print.

ABSTRACT

In seasonal breeders, such as amphibians, testicular functions depend on complex processes that change according to seasonality, including Leydig cell (LC) differentiation and lipid-dependent steroidogenesis, extracellular proteins remodeling and actin-dependent cellular dynamics. Speculating that fat bodies (FB) could support some of these processes in L. catesbeian us, we evaluated bilaterally the FB weights, correlating them to testicular parameters such as weight, testosterone (T) immunoexpression, mast cells (MC) number, vascularization and structural proteins. In an attempt to better understand the testicular asymmetry in amphibians, correlations between these different testicular parameters were also established. Right testes (RT), left testes (LT) and associated FB of bullfrogs were weighed, and testes were processed for light and transmission electron microscopy. Collagen content (COL) and MC number were quantified. T and actin immunoexpressions and vascular areas were measured. Statistical analyses and Pearson's correlation were performed. The LT and its associated FB were heavier than the right ones, and showed intense T and actin immunoexpressions, numerous lipid-rich LC, and greater MC number, COL and vascularization than the RT. Positive correlations were detected between: a) FB and testis weights, b) T immunoexpression and testis and FB weights, c) T and actin immunoexpressions and COL. Otherwise, MC number was inversely correlated to T immunoexpression and COL. In right and left sides, the proportional correlation between T immunoexpression and FB weight suggests that FB-stored lipid amount depends on the steroidogenic demand of its associated testis. Thus, the asymmetry in the testes and FB may be associated, at least in part, to the LC steroidogenic activity, which tends to be more intense in LT than in RT. The results also point to a role of COL and mast cells in the LC differentiation and steroidogenesis. Actin was also greater in LT and correlated with T immunoexpression, indicating that the amount of this structural protein depends on androgenic control. Therefore, the testicular asymmetry in bullfrogs seems to be associated to different morphofunctional processes occurring, bilaterally, at different intensities. In this case, there is a tendency of LT, in association with its FB, to be more active th an RT. The findings highlight the FB-testis interplay for the comprehension of reproduction in amphibians.

PMID:35287007 | DOI:10.1016/j.acthis.2022.151873

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Coblation intracapsular tonsillectomy: a cohort study of NHS practice in England using Hospital Episode Statistics

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Abstract

Objectives

To identify paediatric intracapsular Coblation tonsillectomy procedures from routine administrative data in England, and determine their safety.

Design

Retrospective observational cohort study of four ENT centres using routine data from Hospital Episode Statistics (HES).

Setting

Acute NHS trusts in England conducting exclusively intracapsular Coblation tonsillectomy

Participants

Children (≤16 years old) undergoing bilateral intracapsular Coblation tonsillectomy

Main outcome measures

Number of procedures, readmissions for pain, readmissions for bleeding and requirement for additional surgery for regrowth.

Results

5525 procedures were identified. The median patient age was 4 (IQR 2-5). In-hospital complications occurred in 1%, with 0.1% returning to theatre for arrest of primary tonsil bleeding. Almost half of the procedures were conducted as a day-case (44%), with only a small proportion staying in hospital more than one night (7%). Within 28 days, 1.2% of patients were readmitted with bleeding, 0.7% with infection and 0.3% with pain. 0.2% of patients required return to theatre for control of secondary haemorrhage. Longitudinal follow-up has found that revision tonsil surgery is 0.3% at 1 year (n=4498), 1.1% at 2 years (n=2938), 1.7% at 3 years (n=1781), 1.9% at 4 years (n=905), 2.2% at 5 years (n=305)

Conclusions

Intracapsular coblation tonsillectomy safety outcomes in this study show primary and secondary bleed rates and emergency return to theatre rates are lower than all tonsillectomy techniques reported in the National Prospective Tonsillectomy Audit and also lower than previously published Hospital Episode Statistics analysis of tonsillectomy procedures.

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CircEIF5 contributes to hyperproliferation and inflammation of keratinocytes in psoriasis via p‐NFκB and p‐STAT3 signaling pathway

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Abstract

Psoriasis is a chronic, immune mediated skin disease accompanied by hyperproliferation and inflammation of keratinocytes. Circular RNAs (circRNAs) as new players regulating the development of psoriasis have been reported in recent years. However, its mechanism has not yet been fully revealed. In this study we identified that hsa_circ_0033469 (circEIF5) was highly expressed in psoriasis tissues compared to the normal skin. We investigated the functional roles of circEIF5 in proliferation and inflammatory of HaCat cells under M5-stimulated inflammatory condition. By using a approach of knockdown and overexpression of circEIF5, we showed that circEIF5 could promote proliferation by facilitating the G1/S transition and increase secretion of chemokines in HaCat cells. These moderating effects of circEIF5 were associated with the activating of the NF-κB and STAT3 signaling pathways. Moreover, NF-κB and STAT3 inhibition abrogated circEIF5 induced promotion of cell proliferation and che mokine secretion. These results indicated that through NF-κB and STAT3 signaling pathways, circEIF5 regulated the proliferation and chemokine secretion of HaCat cells and contributed to the pathogenesis of psoriasis, which might become a potent target for psoriasis treatment.

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