Proteomic Profiling of Muscular Adaptations to Short-Term Concentric Versus Eccentric Exercise Training in Humans.

The molecular mechanisms underlying muscular adaptations to concentric (CON) and eccentric (ECC) exercise training have been extensively explored. However, most previous studies have focused on specifically selected proteins, thus, unable to provide a comprehensive protein profile and potentially missing the crucial mechanisms underlying muscular adaptation to exercise training. We herein aimed to investigate proteomic profiles of human skeletal muscle in response to short-term resistance training. Twenty young males were randomly and evenly assigned to two groups to complete a 4-week either ECC or CON training program. Measurements of body composition and physiological function of the quadriceps femoris were conducted both before and after the training. Muscle biopsies from the vastus lateralis of randomly selected participants (five in ECC and four in CON) of both before and after the training were analyzed using the liquid-chromatography tandem mass spectrometry in combination with bioinformatics analysis. Neither group presented a significant difference in body composition or leg muscle mass; however, muscle peak torque, total work, and maximal voluntary contraction were significantly increased after the training in both groups. Proteomics analysis revealed 122 differentially abundant proteins (DAPs; p value < 0.05 & fold change >1.5 or <0.67) in ECC, of which the increased DAPs were mainly related to skeletal muscle contraction and cytoskeleton and enriched specifically in the pentose phosphate pathway, extracellular matrix-receptor interaction, and PI3K-Akt signaling pathway, whereas the decreased DAPs were associated with the mitochondrial respiratory chain. One hundred one DAPs were identified in CON, of which the increased DAPs were primarily involved in translation/protein synthesis and the mitochondria respiratory, whereas the decreased DAPs were related to metabolic processes, cytoskeleton, and de-ubiquitination. In conclusion, the 4-week CON and ECC training resulted in distinctly different proteomic profiles, especially in proteins related to muscular structure and metabolism.

Inverted Internal Limiting Membrane Flap versus Internal Limiting Membrane Insertion Technique for Large Macular Holes: A Meta-Analysis.

PURPOSES: This meta-analysis aimed to compare and evaluate the morphological and functional outcomes between the inverted internal limiting membrane (ILM) flap and ILM insertion techniques in the treatment of large macular holes (MHs). METHODS: The PubMed, Embase, and Cochrane Library databases were searched for relevant studies comparing the two techniques for the treatment of large MHs. The primary outcome measures included the MH closure rate, preoperative and postoperative best-corrected visual acuity (BCVA), MH closure patterns, and external limiting membrane (ELM) and ellipsoid zone (EZ) recovery. Statistical analyses were performed using RevMan 5.3 software. RESULTS: Two randomized controlled trials and four retrospective studies were included in this meta-analysis. The MH closure rate did not significantly differ between the two groups (P = .93). Postoperative BCVA was not significantly different between the two groups at 3 months (P = .20) or 6 months (P = .51). ELM and EZ recovery were also similar between the two groups. However, the results for postoperative BCVA and outer retinal structure recovery tended to favor the ILM flap group based on the forest plot. There was no significant difference between the two groups for the U-shape (P = .26), V-shape (P = .65), and W-shape closure types (P = .38). CONCLUSIONS: Our meta-analysis provides evidence that the MH closure rate and visual function outcomes are similar between the ILM flap and ILM insertion techniques in large MHs. However, based on the forest plot, postoperative BCVA and outer retinal layer reconstruction tended to favor the ILM flap technique. Further studies with larger sample sizes are required to confirm the superiority of the ILM flap to the ILM insertion technique.

Targeted Lipidomics and Inflammation Response to Six Weeks of Sprint Interval Training in Male Adolescents.

Lipids play an important role in coordinating and regulating metabolic and inflammatory processes. Sprint interval training (SIT) is widely used to improve sports performance and health outcomes, but the current understanding of SIT-induced lipid metabolism and the corresponding systemic inflammatory status modification remains controversial and limited, especially in male adolescents. To answer these questions, twelve untrained male adolescents were recruited and underwent 6 weeks of SIT. The pre- and post-training testing included analyses of peak oxygen consumption (VO2peak), biometric data (weight and body composition), serum biochemical parameters (fasting blood glucose, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triacylglycerol, testosterone, and cortisol), inflammatory markers, and targeted lipidomics. After the 6-week SIT, the serum C-reactive protein (CRP), interleukin (IL)-1ß, IL-2, IL-4, IL-10, tumor necrosis factor (TNF)-α, and transforming growth factor (TGF)-ß significantly decreased (p < 0.05), whereas IL-6 and IL-10/TNF-α significantly increased (p < 0.05). In addition, the targeted lipidomics revealed changes in 296 lipids, of which 33 changed significantly (p < 0.05, fold change > 1.2 or <1/1.2). The correlation analysis revealed that the changes in the inflammatory markers were closely correlated with the changes in some of the lipids, such as LPC, HexCer, and FFA. In conclusion, the 6-week SIT induced significant changes in the inflammatory markers and circulating lipid composition, offering health benefits to the population.

Induction of Differentiation of Mesenchymal Stem Cells into Retinal Pigment Epithelial Cells for Retinal Regeneration by Using Ciliary Neurotrophic Factor in Diabetic Rats.

Diabetic retinopathy (DR) is a common cause of blindness all over the world. Bone marrow mesenchymal stem cells (BMSCs) have been considered as a promising strategy for retinal regeneration in the treatment of DR. However, the poor viability and low levels of BMSCs engraftment limit the therapeutic potential of BMSCs. The present study aimed to examine the direct induction of BMSCs differentiation into the cell types related to retinal regeneration by using soluble cytokine ciliary neurotrophic factor (CNTF). We observed remarkably increased expression of cellular retinaldehyde-binding protein (CRALBP) and retinoid isomerohydrolase (RPE65) in BMSCs treated with CNTF in vitro, indicating the directional differentiation of BMSCs into the retinal pigment epithelium (RPE) cells, which are crucial for retinal healing. In vivo, the diabetic rat model was established by use of streptozotocin (STZ), and animals treated with BMSCs+CNTF exhibited better viability and higher delivery efficiency of the transplanted cells than those treated with BMSCs injection alone. Similar to the in-vitro result, treatment with BMSCs and CNTF combined led to the differentiation of BMSCs into beneficial cells (RPE cells), and accelerated retinal healing characterized by the activation of rod photoreceptor cells and phagocytosis function of RPE cells. In conclusion, CNTF contributes to the differentiation of BMSCs into RPE cells, which may help overcome the current stem cell therapy limitations in the field of retinal regeneration.

Phacoemulsification with Goniosynechialysis versus Phacoemulsification Alone in Angle-Closure Glaucoma: A Meta-Analysis of Randomized Controlled Trials.

PURPOSE: This meta-analysis aimed to compare the efficacy and safety of phacoemulsification with goniosynechialysis (Phaco-GSL) with those of phacoemulsification alone (Phaco-alone) in patients with angle-closure glaucoma and cataract. METHODS: Randomized controlled trials (RCTs) were selected through a search of electronic databases. Trial eligibility and risk of bias were assessed using Cochrane review methods. Primary measures included the intraocular pressure (IOP), number of antiglaucoma medications, peripheral anterior adhesion (PAS) extent, and their pre- and postoperative changes. For continuous parameters, we calculated weighted mean differences and 95% confidence intervals. Statistical analysis was performed using RevMan 5.3 software. RESULTS: Eight RCTs were included, where 224 and 236 eyes were in the Phaco-GSL and Phaco-alone groups, respectively. Both postoperative IOP and number of medications were not significantly different between the study groups at the six- and twelve-month follow-up. However, the 12-month postoperative PAS extent was significantly smaller in the Phaco-GSL group than in the Phaco-alone group. Similarly, changes from the preoperative to 12-month postoperative PAS extent were significantly greater in the Phaco-GSL group than in the Phaco-alone group, but IOP and the number of medication changes were not different. CONCLUSIONS: Our results provide evidence that Phaco-GSL provides advantages over Phaco-alone treatment regarding PAS reduction. In terms of IOP and medication reduction, both groups were comparable. Thus, Phaco-GSL can be considered for the treatment of patients with angle-closure glaucoma and cataract due to its ease, safety, and potential benefit for the anterior chamber angle.

Inverted Internal Limiting Membrane Flap Technique versus Internal Limiting Membrane Peeling for Large Macular Holes: A Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Vitrectomy with internal limiting membrane (ILM) peeling is an effective surgical procedure for the treatment of macular holes (MHs). However, there is a possibility of poor postoperative anatomical closure with conventional ILM peeling for MHs larger than 400 µm. Therefore, a novel inverted ILM flap technique was developed for such cases. OBJECTIVES: This meta-analysis study was performed to evaluate and compare the anatomical and visual outcomes of the inverted ILM flap technique and ILM peeling in large MHs. METHODS: The Cochrane Library, PubMed, and Embase databases were searched to identify randomized controlled trials (RCTs). The trial eligibility and risk of bias were assessed according to Cochrane review methods. The primary outcome measures included MH closure rate and postoperative visual acuity (VA). Subgroup analysis of postoperative VA based on follow-up time was also conducted. Pooled odds ratios (ORs), weighted mean difference (WMD), and 95% confidence intervals (CIs) were calculated. Statistical analysis was performed using RevMan 5.3 software. RESULTS: Five RCTs with a total of 155 eyes in the inverted ILM flap group and 161 eyes in the ILM peeling group were included in this meta-analysis. Statistical meta-analysis revealed that the overall MH closure rate in the inverted ILM flap group was significantly higher than that in the ILM peeling group (OR = 3.10; 95% CI: 1.25-7.66; p = 0.01). The postoperative VA was significantly better in the inverted ILM flap group than the ILM peeling group (WMD = -0.14; 95% CI: -0.21 to -0.07; p = 0.0002). The subgroup meta-analysis indicated that the postoperative VA was significantly better in the inverted ILM flap group than the ILM peeling group (WMD = -0.17; 95% CI: -0.26 to -0.08; p = 0.0004) at the 3-month follow-up. However, no significant difference was observed between the 2 groups at the 6-month follow-up (WMD = -0.09; 95% CI: -0.20 to 0.02; p = 0.10). CONCLUSIONS: Vitrectomy with the inverted ILM flap technique showed a higher anatomical closure rate as well as visual gain - although only in the short term as no difference in visual recovery was found at the 6-month follow-up - than did ILM peeling in large MHs. The inverted ILM flap technique should be considered as a preferred and routine procedure for the treatment of patients with MHs larger than 400 µm.

Angiotensin-Converting Enzyme Gene D/I Polymorphism in Relation to Endothelial Function and Endothelial-Released Factors in Chinese Women.

Many studies have investigated the relationship between angiotensin-converting enzyme (ACE) D/I polymorphism and cardiovascular disease or endothelial dysfunction; however, hardly any of these studies has taken aging or menopause into consideration. Furthermore, despite that many studies have examined the regulatory effects of endothelial-released factors (ERFs) on endothelial function, no study has evaluated the relationship between ERFs and endothelial function with respect to ACE D/I polymorphism and menopause status. To answer these questions, 391 healthy Chinese women over a wide range of ages (22-75 years) were enrolled and divided into pre-menopause group and post-menopause group. After ACE D/I genotype being identified, the women were then classified into either DI/II or DD genotype. Flow-mediated dilatation (FMD) of brachial endothelium and plasma levels of ERFs: nitric oxide (NO), endothelin-1 (ET-1), and angiotensin II (Ang II) were measured. The results showed that frequencies of ACE D/I genotypes were in accordance with the Hardy-Weinberg equilibrium, and the frequency of I allele was higher than D allele. In pre-menopause group, FMD was significantly higher in women of DI/II than DD (P = 0.032), and age-dependent in both genotypes (DD, P = 0.0472; DI/II, P < 0.0001). In post-menopause group, FMD was similar between women of DI/II and DD, and age-dependent only in women of DI/II (P < 0.0001). In pre-menopause group, Ang II level was significantly higher in women of DD than DI/II (P = 0.029), and FMD was significantly correlated with all ERFs in women of DD (NO, P = 0.032; ET-1, P = 0.017; Ang II, P = 0.002), but only with Ang II in women of DI/II (P = 0.026). In post-menopause group, no significant difference was observed in any ERF between women of DI/II and DD, and FMD was only significantly correlated with ET-1 in women of DD (P = 0.010). In summary, FMD in women of DI/II was superior to DD in pre-menopause and more age-dependent than DD in post-menopause, and FMD was closely associated with ERFs. In conclusion, Chinese women of DI/II seem to have lower risk than DD in pre-menopause, but similar risk as DD in post-menopause in developing cardiovascular disease.

Potential effects of long-term abuse of anabolic androgen steroids on human skeletal muscle.

BACKGROUND: We have previously evaluated muscle functions and morphology in power athletes of long term (5 to15 years) abuse of anabolic androgen steroids (AAS; Doped) and in clean power athletes (Clean), and observed significant improvements in both muscle morphology and muscle functions in Doped. To our knowledge, the effects of long term AAS abuse on human muscle protein profile have never been studied. METHODS: The study examined further the muscle biopsies using a two-dimensional difference gel electrophoresis (2D DIGE) for proteomic screening and protein expression. Cellular localization/distribution of specific proteins identified by proteomic analysis was examined using immunohistochemistry (IHC). RESULTS: Different protein profiles were observed between Doped and Clean, and a valid orthogonal projection of latent structure discriminant analysis model was built (N.=16, x=5, R2=0.88/Q2=0.84, P=0.0005), which separated Doped from Clean. Liquid chromatography followed by tandem spectrometry identified 14 protein spots (representing nine different proteins) of significant difference in relative quantity (P<0.05), of which nine spots were down-regulated in Doped compared with Clean. IHC revealed no significant alteration in cellular localization in phosphoglucomutase-1 and heat shock protein beta-1, but indeed in two reference proteins desmin and F-actin in Doped. CONCLUSIONS: Long term abuse of AAS in combination with training is potentially associated with alterations in skeletal muscle protein profile and protein expression, and structural proteins rather than non-structural proteins are preferentially affected in cellular localization/distribution.

Macular hole surgery recovery with and without face-down posturing: a meta-analysis of randomized controlled trials.

BACKGROUND: After pars plana vitrectomy with internal limiting membrane (ILM) peeling and gas tamponade, patients are often required to remain in a face-down position (FDP) to allow the gas bubble to push against the macular hole (MH) to promote hole closure. However, this position may be uncomfortable and inconvenient for the elderly and those with medical comorbidities; it may also lead to certain postoperative complications. Hence, this study aimed to evaluate and compare the effect of postoperative FDP and non-face-down position (nFDP) on the closure rate of MHs following MH surgery. METHODS: Randomized controlled trials (RCTs) were selected through an electronic search of the Cochrane Library, Pubmed, and Embase databases. Trial eligibility and risk of bias were assessed according to Cochrane review methods. The primary measures included overall MH closure rate and subgroup analysis based on MH size. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were estimated. Statistical analysis was performed using RevMan 5.0 software and Stata software 15.0. RESULTS: Five RCTs composed of a total of 183 eyes in the FDP group and 175 eyes in the nFDP group were included in this meta-analysis. Statistical meta-analysis revealed that the overall MH closure rate in the FDP group was significantly higher than that in the nFDP group (OR = 2.27, 95% CI: 1.02 to 5.05, P = 0.04). For MH sizes smaller than 400 µm, the subgroup meta-analysis indicated that the closure rate of the FDP group was not significantly higher than that of the nFDP group (OR = 1.32, 95% CI: 0.39 to 4.49, P = 0.66). However, when MH size was larger than 400 µm, there was a significantly higher closure rate in the FDP group (OR = 2.95, 95% CI: 1.10 to 7.94, P = 0.03). CONCLUSIONS: Our results provide evidence that a face-down postoperative position seems to be unnecessary when MHs are smaller than 400 µm but may be highly recommended for MHs larger than 400 µm. Further RCTs with large sample sizes are warranted to validate these findings in future.

Could the negative effects of static stretching in warm-up be balanced out by sport-specific exercise?

BACKGROUND: Static stretching (SS) is widely used in warm-up as it is generally believed to increase mobility and reduce the risk of injury; however, SS has been shown to induce transient negative effects on subsequent muscle performance. Interestingly, recent studies have shown that sport-specific exercise could restore SS-induced negative effects on certain sports, especially of explosive muscular performance. Whether sport-specific exercise could restore SS-induced negative effects on isokinetic muscle performance remains unclear. METHODS: The present study conducted two different warm-ups: 2-component warm-up and 3-component warm-up on 15 university students. Both protocols contained low intensity aerobic exercise and sport-specific exercise, whereas the 3-component warm-up also contained SS which has been previously proven to induce negative effects on subsequent muscle performance. After the warm-ups, the subjects performed an isokinetic test on a Biodex. In order to make the sport-specific exercise mimic the subsequent test, both included concentric isokinetic knee extension. During the tests, muscle performance of peak torque, mean power, and total work was recorded. Comparison of the measurements on each parameter between the two warm-ups was performed using paired t-test. RESULTS: The comparisons did not reveal any significant difference in the measurement of any parameter between the two different warm-up protocols, and calculation of Cohen's d revealed small effect sizes on all of the three variables. CONCLUSIONS: On the basis of the study results, we concluded that the negative effects of the SS on the variables were restored by the isokinetic contractions.

Retinal Nerve Fiber Layer Thickness Changes in the Pseudoexfoliation Syndrome: A Meta-Analysis of Case-Control Studies.

PURPOSE: To evaluate and compare changes in retinal nerve fiber layer (RNFL) thickness in patients with the pseudoexfoliation syndrome (PXS) and healthy controls. METHODS: Case-control studies were selected through an electronic search of the Cochrane Controlled Trials Register, PubMed, and Embase. Results were reviewed to ensure that the included studies met prespecified inclusion/exclusion criteria, and the quality of each study was assessed using the Newcastle-Ottawa Scale. All included studies measured average and 4-quadrant (temporal, superior, nasal, and inferior) RNFL thickness using optical coherence tomography (OCT). For the continuous outcomes, we calculated the weighted mean difference (WMD) and 95% confidence intervals (CIs). RESULTS: Eight case-control studies were included in this meta-analysis involving 225 eyes of PXS patients and 208 eyes of healthy controls in total. Statistical analysis revealed that the average RNFL thickness in PXS patients was significantly reduced compared to healthy controls (WMD = -6.91, 95% CI: -9.99 to -3.82, p < 0.0001). Additionally, differences in RNFL thickness in the superior quadrant (WMD = -10.68, 95% CI: -16.40 to -4.95, p = 0.0003), inferior quadrant (WMD = -8.20, 95% CI: -10.85 to -5.55, p < 0.00001), nasal quadrant (WMD = -3.05, 95% CI: -5.21 to -0.90, p = 0.005), and temporal quadrant (WMD = -6.39, 95% CI: -9.98 to -2.80, p = 0.0005) were all significant between the two groups. CONCLUSIONS: These results suggest that it is important to evaluate RNFL thickness and the optic nerve head through OCT in patients with PXS in order to determine early glaucomatous damage and start timely intervention prior to visual field loss.

Evaluation of biometry and corneal astigmatism in cataract surgery patients from Central China.

BACKGROUND: To evaluate the distribution of biometric parameters and corneal astigmatism using the IOLMaster device before phacoemulsification in cataract patients in Central China. METHODS: Consecutive cataract patients were recruited at the Central Hospital of Wuhan between January 2015 and June 2016. Ocular axial length (AL), keratometry values, anterior chamber depth (ACD) and horizontal corneal diameter (white to white [WTW]) of each cataract-affected eye were measured with the IOLMaster device. RESULTS: The study evaluated 3209 eyes of 2821 cataract patients. The mean AL, ACD, and WTW were 24.38 ± 2.47 mm, 3.15 ± 0.48 mm, and 11.63 ± 0.43 mm, respectively. Corneal astigmatism of 0.51-1.00 diopters (D) was the most common range of values (34.96%). A total of 10.56% patients exhibited a corneal astigmatism greater than 2.0 D. The flat and steep keratometry values gradually increased with age. The mean ACD and WTW showed increasing trends as the AL increased (P < 0.001). When the AL was shorter than 26.0 mm, the keratometry decreased as AL increased. The against-the-rule (ATR) astigmatism proportion increased with age and the with-the-rule (WTR) astigmatism proportion decreased with age. CONCLUSIONS: The profile of ocular biometric data and corneal astigmatism may help ophthalmologists improve their surgical procedures and make an appropriate IOL choice to gain a high quality of postoperative vision.

Vitamin D in relation to bone health and muscle function in young female soccer players.

The present work investigated serum vitamin D (25(OH)D) status in relation to bone and muscle qualities and functions in 19 female soccer players (13-16 years) resident at northern latitude with very low sun exposure (∼32-36 h/month) during winter season (late January to early March). Serum 25(OH)D, parathyroid hormone and bone turnover markers osteocalcin (OC) and beta carboxy-terminal collagen cross-links (ß-Ctx), as well as body composition and muscle performance were examined. Hormones were tested using routine laboratory methods. Fat mass, lean mass, and bone mineral density in whole body, as well as femur and lumbar spine were evaluated with dual-energy X-ray absorptiometry. Muscle performance was assessed through isokinetic knee extension and flexion, countermovement jump, and sprint running. 25(OH)D was low (50.5 ± 12.8 nmol l-1), whereas the values of bone turnover markers were markedly high (OC: 59.4 ± 18.6 µg l-1; ß-Ctx: 1075 ± 408 ng l-1). All bone and muscle measurements were normal or above normal. 25(OH)D was not significantly correlated with most of the parameters of bone and muscle quality or function, except the knee extension time to peak torque (r = -0.50, p = .03). In conclusion, the level of vitamin D is markedly low in adolescent female soccer players during the winter in Sweden. However, vitamin D levels did not significantly correlate with measures of bone and muscle except a moderate correlation in time to peak torque in the knee extensors. The practical implication of low vitamin D levels in young growing female athletes remains unclear.

Comparison between Subjective Sensations during First and Second Phacoemulsification Eye Surgeries in Patients with Bilateral Cataract.

Purpose. To evaluate and compare the subjective sensations reported by patients during first and second cataract extractions. Methods. Consecutive patients undergoing bilateral sequential cataract extraction using phacoemulsification were recruited. Following cataract surgery, patients completed questionnaires designed to evaluate subjective sensations, including anxiety, eye bulges, pain, and light sensitivity. Changes in painful sensations experienced by patients between the two surgeries were also recorded. Comparisons were also performed for each subjective sensation between different age groups (<50, 50-59, 60-69, 70-79, and >79 years). Results. A total of 127 patients were included in the final evaluation. Statistical comparison of the results showed that there were significant differences in perception of anxiety, eye bulges, and pain scores between the first and second cataract surgeries (P < 0.05). However, there was no statistically significant difference for light sensitivity scores between the two surgeries (P = 0.555). The differences in anxiety, perception of eye bulges, pain, and light sensitivity scores between both the surgeries showed no correlation with age (P > 0.05 for all). Conclusions. Our research confirms the common observation that patients with bilateral cataracts often report more ocular discomfort during the second surgery. There are, therefore, additional factors that should be considered upon treating patients with bilateral cataracts, and the provision of preoperative counseling could play an important role in providing adequate patient care.

Changes in Retinal Nerve Fiber Layer Thickness in Obstructive Sleep Apnea/Hypopnea Syndrome: A Meta-Analysis.

PURPOSE: To evaluate and compare changes in retinal nerve fiber layer (RNFL) thickness in patients with obstructive sleep apnea/hypopnea syndrome (OSAHS). METHODS: The Cochrane Library, Medline, and Embase were screened using our key words. Results were carefully reviewed to ensure that the included studies met the inclusion/exclusion criteria, and the quality of the studies was assessed using the Newcastle-Ottawa Scale. All included studies categorized patients with OSAHS into 3 groups (mild, moderate, and severe), and measured average and 4-quadrant (temporal, superior, nasal, and inferior) RNFL thickness. All studies included a healthy control group. The weighted mean differences and 95% confidence intervals were calculated for the continuous outcomes. RESULTS: Ten case-control studies were included in the meta-analysis, consisting of a total of 811 OSAHS group and 868 healthy eyes. A meta-analysis of the data showed that the average RNFL thicknesses in the mild, moderate, and severe OSAHS groups were significantly decreased compared to healthy controls. Additionally, RNFL thickness was significantly reduced in all but the temporal quadrant in the moderate and severe OSAHS groups when compared to healthy controls. CONCLUSIONS: On the basis of these results, we suggest that peripapillary RNFL thickness as measured by optical coherence tomography could be a useful tool to monitor and assess the severity of OSAHS in patients. Further studies are required in order to differentiate these RNFL changes from glaucomatous changes. This has not been properly examined in any of the studies we were able to identify.

Retinal Nerve Fiber Layer Thickness Changes in Migraine: A Meta-Analysis of Case-Control Studies.

BACKGROUND: The neurovascular dysfunction appears to be related to the development of migraines and it could be possible that hypoperfusion might also involve other areas besides brain, including the retina. Numerous studies have analyzed the ability of optical coherence tomography (OCT) to detect retinal nerve fiber layer (RNFL) thickness abnormalities and changes in migraine, but the results have not always been consistent. Therefore, we carried out a meta-analysis to evaluate the RNFL thickness measured with OCT in migraine. METHODS: Case-control studies were selected through an electronic search of the Cochrane Controlled Trials Register, PUBMED and EMBASE. For the continuous outcomes, we calculated the weighted mean difference (WMD) and 95% confidence interval (CI). The statistical analysis was performed by RevMan 5.0 software. RESULTS: Six case-control studies were included in the present meta-analysis, containing a total of 432 eyes in migraine patients and 288 eyes in healthy controls. The results of our study showed that there was a significant reduction in average RNFL thickness in patients with migraine compared to healthy controls (WMD = -3.67, 95% CI: -6.84 to -0.49, p = 0.02). Additionally, differences of RNFL thickness in superior quadrant (WMD = -9.23, 95% CI: -15.63 to -2.82, p = 0.005), inferior quadrant (WMD = -3.47, 95% CI: -6.73 to -0.22, p = 0.04), nasal quadrant (WMD = -3.86, 95% CI: -7.10 to -0.61, p = 0.02) and temporal quadrant (WMD = -3.10, 95% CI: -5.05 to -1.15, p = 0.002) were all significant between the two groups. CONCLUSIONS: Our meta-analysis found that RNFL thickness in the migraine patients was thinner than that in the healthy control group. Given the limited sample size, further investigations are needed to validate these findings.

A prospective study on postoperative discomfort after 20-gauge pars plana vitrectomy.

PURPOSE: To evaluate postoperative pain and other irritation symptoms after 20-gauge (20G) pars plana vitrectomy. MATERIALS AND METHODS: A total of 110 consecutive patients were enrolled in our studies, and 87 patients who underwent the conventional 20G pars plana vitrectomy were included in the final analysis. All vitrectomies were performed using the same surgical technique by the same surgeon. Patients were examined before surgery and 1 day, 3 days, 7 days, 1 month, and 2 months postoperatively. The main outcome measures include patient age and sex, intraocular pressure (IOP), ocular pain, pain score, pain medication use, and other irritation symptoms comprising itching, foreign body sensation, burning, photophobia, and dryness. The pain was evaluated using the Numerical Rating Scale scored from 0 to 10. RESULTS: Postoperative pain was relatively common during the first day after surgery, as it was reported by 43 (49.4%) patients. Then, the prevalence gradually decreased to eleven (12.6%) patients at 2 months. Most patients reported mild or moderate pain, with a pain score of 1-5, but only four patients were given analgesics for ocular pain. A postoperative rise of IOP was noted in 25 patients at day 1. Most of these patients with high IOP reported moderate pain. Other ocular irritation symptoms were varied after surgery. There was still one-quarter of patients that had foreign body sensation and dryness symptoms at month 2 after surgery. CONCLUSION: Mild and moderate ocular pain were relatively common after 20G vitrectomy, which is more often associated with elevated IOP. Other irritation symptoms were also presented after surgery and could affect the life quality of patients. Therefore, the discomforts after 20G pars plana vitrectomy should be of concern, and timely management should be provided as part of routine postoperative care.

Unilateral muscle overuse causes bilateral changes in muscle fiber composition and vascular supply.

Unilateral strength training can cause cross-transfer strength effects to the homologous contralateral muscles. However, the impact of the cross-over effects on the muscle tissue is unclear. To test the hypothesis that unilateral muscle overuse causes bilateral alterations in muscle fiber composition and vascular supply, we have used an experimental rabbit model with unilateral unloaded overstrain exercise via electrical muscle stimulation (E/EMS). The soleus (SOL) and gastrocnemius (GA) muscles of both exercised (E) and contralateral non-exercised (NE) legs (n = 24) were morphologically analyzed after 1 w, 3 w and 6 w of EMS. Non-exercised rabbits served as controls (n = 6). After unilateral intervention the muscles of both E and NE legs showed myositis and structural and molecular tissue changes that to various degrees mirrored each other. The fiber area was bilaterally smaller than in controls after 3 w of E/EMS in both SOL (E 4420 and NE 4333 µm2 vs. 5183 µm2, p<0.05) and GA (E 3572 and NE 2983 µm2 vs. 4697 µm2, p<0.02) muscles. After 6 w of E/EMS, the percentage of slow MyHCI fibers was lower than in controls in the NE legs of SOL (88.1% vs. 98.1%, p<0.009), while the percentage of fast MyHCIIa fibers was higher in the NE legs of GA (25.7% vs. 15.8%, p = 0.02). The number of capillaries around fibers in the E and NE legs was lower (SOL 13% and 15%, respectively, GA 25% and 23%, respectively, p<0.05) than in controls. The overall alterations were more marked in the fast GA muscle than in the slow SOL muscle, which on the other hand showed more histopathological muscle changes. We conclude that unilateral repetitive unloaded overuse exercise via EMS causes myositis and muscle changes in fiber type proportions, fiber area and fiber capillarization not only in the exercised leg, but also in the homologous muscles in the non-exercised leg.

Effects of long term supplementation of anabolic androgen steroids on human skeletal muscle.

The effects of long-term (over several years) anabolic androgen steroids (AAS) administration on human skeletal muscle are still unclear. In this study, seventeen strength training athletes were recruited and individually interviewed regarding self-administration of banned substances. Ten subjects admitted having taken AAS or AAS derivatives for the past 5 to 15 years (Doped) and the dosage and type of banned substances were recorded. The remaining seven subjects testified to having never used any banned substances (Clean). For all subjects, maximal muscle strength and body composition were tested, and biopsies from the vastus lateralis muscle were obtained. Using histochemistry and immunohistochemistry (IHC), muscle biopsies were evaluated for morphology including fiber type composition, fiber size, capillary variables and myonuclei. Compared with the Clean athletes, the Doped athletes had significantly higher lean leg mass, capillary per fibre and myonuclei per fiber. In contrast, the Doped athletes had significantly lower absolute value in maximal squat force and relative values in maximal squat force (relative to lean body mass, to lean leg mass and to muscle fiber area). Using multivariate statistics, an orthogonal projection of latent structure discriminant analysis (OPLS-DA) model was established, in which the maximal squat force relative to muscle mass and the maximal squat force relative to fiber area, together with capillary density and nuclei density were the most important variables for separating Doped from the Clean athletes (regression  =  0.93 and prediction  =  0.92, p<0.0001). In Doped athletes, AAS dose-dependent increases were observed in lean body mass, muscle fiber area, capillary density and myonuclei density. In conclusion, long term AAS supplementation led to increases in lean leg mass, muscle fiber size and a parallel improvement in muscle strength, and all were dose-dependent. Administration of AAS may induce sustained morphological changes in human skeletal muscle, leading to physical performance enhancement.

Inhibitors of endopeptidase and angiotensin-converting enzyme lead to an amplification of the morphological changes and an upregulation of the substance P system in a muscle overuse model.

BACKGROUND: We have previously observed, in studies on an experimental overuse model, that the tachykinin system may be involved in the processes of muscle inflammation (myositis) and other muscle tissue alterations. To further evaluate the significance of tachykinins in these processes, we have used inhibitors of neutral endopeptidase (NEP) and angiotensin-converting enzyme (ACE), substances which are known to terminate the activity of various endogenously produced substances, including tachykinins. METHODS: Injections of inhibitors of NEP and ACE, as well as the tachykinin substance P (SP), were given locally outside the tendon of the triceps surae muscle of rabbits subjected to marked overuse of this muscle. A control group was given NaCl injections. Evaluations were made at 1 week, a timepoint of overuse when only mild inflammation and limited changes in the muscle structure are noted in animals not treated with inhibitors. Both the soleus and gastrocnemius muscles were examined morphologically and with immunohistochemistry and enzyme immunoassay (EIA). RESULTS: A pronounced inflammation (myositis) and changes in the muscle fiber morphology, including muscle fiber necrosis, occurred in the overused muscles of animals given NEP and ACE inhibitors. The morphological changes were clearly more prominent than for animals subjected to overuse and NaCl injections (NaCl group). A marked SP-like expression, as well as a marked expression of the neurokinin-1 receptor (NK-1R) was found in the affected muscle tissue in response to injections of NEP and ACE inhibitors. The concentration of SP in the muscles was also higher than that for the NaCl group. CONCLUSIONS: The observations show that the local injections of NEP and ACE inhibitors led to marked SP-like and NK-1R immunoreactions, increased SP concentrations, and an amplification of the morphological changes in the tissue. The injections of the inhibitors thus led to a more marked myositis process and an upregulation of the SP system. Endogenously produced substances, out of which the tachykinins conform to one substance family, may play a role in mediating effects in the tissue in a muscle that is subjected to pronounced overuse.