Overexpression of PRDM16 Improves Muscle Function after Rotator Cuff Tears.

INTRODUCTION: Muscle atrophy, fibrosis and fatty infiltration (FI) are commonly seen in rotator cuff tears (RCT), which are critical factors that directly determine the clinical outcomes for patients with this injury. Therefore, improving muscle quality after RCT is crucial in improving the clinical outcome of tendon repair. In recent years, it has been discovered that adults have functional beige/brown adipose tissue (BAT) which can secrete batokines to promote muscle growth. PRDM16, a PR-domain containing protein, was discovered with the ability to determine the brown fat cell fate and stimulate its development. Thus, the goal of this study is to discover the role of PRDM16 in improving muscle function after massive tendon tears using a transgenic mouse model with an elevated level of PRDM16 expression. METHODS: Transgenic aP2 driven PRDM16 overexpression mice and C57BL/6J mice underwent unilateral supraspinatus (SS) tendon transection and suprascapular nerve transection (TTDN) as described previously (N=8 in each group). DigiGait was performed to evaluate forelimb function at 6 weeks post the TTDN injury. Bilateral SS muscles, interscapular brown fat, epididymal white fat, and inguinal beige fat were harvested for analysis. The expression of PRDM16 in adipose tissue was detected by Western Blot. Masson's trichome staining was conducted to evaluate the muscle fibrosis and Oil Red O staining was used to determine the fat infiltration. Muscle fiber type was determined by MHC expression via immunostaining. All data was presented in the form of mean±SD. T-test and two-way ANOVA analysis was performed to determine a statistically significant difference between groups. Significance was considered when P<0.05. RESULTS: Western blot data showed an increased expression of PRDM16 protein in both white and brown fat in PRDM16-overexpression mice compared to wild-type (WT) mice. Even though PRDM16 overexpression had no effect on increasing muscle weight, it significantly improved the forelimbs function with longer brake, stance and stride time, larger stride length and paw area in mice after RCT. Additionally, PRDM16 overexpression mice showed no difference in amount of fibrosis when compared to WT mice, however, they had significantly reduced area of fatty infiltration. These mice also exhibited abundant MHC-IIx fiber percentage in supraspinatus muscle after TTDN. CONCLUSION: Overexpression of PRDM16 significantly improved muscle function and reduced fatty infiltration after rotator cuff tears. Promoting BAT activity is beneficial in improving rotator cuff muscle quality and shoulder function after RCT.

Neuromuscular diseases associated with COVID-19 vaccines: a systematic review and pooled analysis of 258 patients.

BACKGROUND: Neuromuscular diseases (NMD) emerged as one of the main side effects of the COVID-19 vaccination. We pooled and summarized the evidence on the clinical features and outcomes of NMD associated with COVID-19 vaccination. METHODS: We comprehensively searched three databases, Medline, Embase, and Scopus, using the key terms covering "Neuromuscular disease" AND "COVID-19 vaccine", and pooled the individual patient data extracted from the included studies. RESULTS: A total of 258 NMD cases following COVID-19 have been reported globally, of which 171 cases were Guillain-Barré syndrome (GBS), 40 Parsonage-Turner syndrome (PTS), 22 Myasthenia Gravis (MG), 19 facial nerve palsy (FNP), 5 single fiber neuropathy, and 1 Tolosa-Hunt syndrome. All (100%) SFN patients and 58% of FNP patients were female; in the remaining NMDs, patients were predominantly male, including MG (82%), GBS (63%), and PTS (62.5%). The median time from vaccine to symptom was less than 2 weeks in all groups. Symptoms mainly appeared following the first dose of vector vaccine, but there was no specific pattern for mRNA-based. CONCLUSION: COVID-19 vaccines might induce some NMDs, mainly in adults. The age distribution and gender characteristics of affected patients may differ based on the NMD type. About two-thirds of the cases probably occur less than 2 weeks after vaccination.

Surgical coronary revascularization in patients with COVID-19; complications and outcomes: A retrospective cohort study.

Background and Aims: Coronary artery disease is high-risk comorbidity of COVID-19 infection. Nonelective coronary artery revascularization in COVID-19 patients carries substantial risk. Therefore, it is essential to understand the risk factors and outcomes fully. This study aims to evaluate the prognosis of coronary artery bypass grafting (CABG) surgery in patients with COVID-19. Methods: This retrospective cohort study assesses 171 patients who underwent urgent and emergent CABG in Tehran Heart Center from March 2020 to September 2021. The patients were allocated to cases and controls based on COVID-19 infection status. Demographic and clinical features, alongside the complications and outcomes, were compared between the two groups. Results: According to diagnostic criteria, 62 patients were diagnosed with COVID-19 (Case) and 109 patients had no COVID diagnosis (Control). Regarding the demographics and risk factors, hypertension was more prevalent among patients with COVID-19 (64.5% compared to 43.1% p= 0.007). Length of hospital stay, ventilation time, and intensive care unit (ICU) stay time were significantly higher in patients infected with COVID-19. Postoperative complications, including stroke, atrial fibrillation, pleural effusion, blood transfusion, and Inotrope use, were significantly higher in the case group. Mortality rates were also higher in COVID-19 patients with an odds ratio of 1.53; however, this difference is not statistically significant (p: 0.44, 95% CI = 0.50-4.01). Conclusion: COVID-19 is associated with a significantly higher hospital stay, ventilation time, and ICU stay. Mortality rates are also higher, albeit insignificantly. Various postoperative complications are also higher with COVID-19.

Complications of single growing rod constructs in the treatment of severe early-onset scoliosis: a lesson relearned.

PURPOSE: Early-onset scoliosis (EOS) is one of the most challenging areas of orthopedic management. Previous studies have reported that EOS patients were associated with high risk of complications following growth-friendly surgery. This study was performed to evaluate the complications of single traditional growing rods (TGRs) in the treatment of EOS. METHODS: In a retrospective chart review study, medical records of all EOS patients treated with single TGRs between 2006 and 2018 were analyzed. Patients under the age of 10 at the time of surgery who had at least 24 months of follow-up were included. Intra- and post-operative complications included both device-related and disease-related complications. Statistical analysis was performed with SPSS. RESULTS: A total of 35 patients with a mean age of 5.7 ± 2.1 years with the mean follow-up duration of 33.3 ± 9.1 months were included in the final analysis. Of the 35 participants, 27 children (77.1%) experienced at least one complication. A total of 61 complications were observed, giving rise to 1.7 complications per patient. An unplanned surgical procedure was needed to manage 42 of the 61 complications (68.8%). Thirty-five cases of implant failure, 11 cases of deep infection, and 2 cases of junctional kyphosis were identified. CONCLUSION: It seems that even in the setting that the use of dual TGRs is not possible, the use of single TGRs as the only therapeutic modality should be minimized due to high rate of complications even as a bridge treatment. LEVEL OF EVIDENCE: Therapeutic level III.