Ten years of enhancing neuro-imaging genetics through meta-analysis: An overview from the ENIGMA Genetics Working Group

Here we review the motivation for creating the enhancing neuroimaging genetics through meta-analysis (ENIGMA) Consortium and the genetic analyses undertaken by the consortium so far. We discuss the methodological challenges, findings, and future directions of the genetics working group. A major goal of the working group is tackling the reproducibility crisis affecting “candidate gene” and genome-wide association analyses in neuroimaging. To address this, we developed harmonized analytic methods, and support their use in coordinated analyses across sites worldwide, which also makes it possible to understand heterogeneity in results across sites. These efforts have resulted in the identification of hundreds of common genomic loci robustly associated with brain structure. We have found both pleiotropic and specific genetic effects associated with brain structures, as well as genetic correlations with psychiatric and neurological diseases.     

The floating cardiac fat pad—sign of occult pneumothorax

Pneumothoraces are a possible sequela of chest trauma with potential morbidity and mortality if not recognized and treated promptly. A portable supine chest radiograph is frequently the first radiologic study performed in the setting of trauma. While large pneumothoraces can be readily recognized on these radiographs, smaller pneumothoraces are missed in up to 15 % of trauma patients. There are many radiographic signs of occult pneumothoraces, and we are presenting a new radiographic sign of occult pneumothorax. The floating cardiac fat pad sign occurs when pleural air collects anteriorly and superiorly in the most non-dependent portion of the chest lifting the pericardial fat pad off the diaphragm. Lung markings are still seen surrounding the pericardial fat pad due to the inflated lower lobe of the lung resting dependently. Rapid and accurate identification of pneumothoraces is critical but often difficult on chest radiographs. Although there are many existing radiographic signs for identification of pneumothorax, prospective identification of small pneumothoraces is still relatively poor. Here, we describe an additional sign which aides in the detection of pneumothoraces, the floating cardiac fat pad. When present, this should prompt further evaluation with chest CT or upright chest radiograph.     

Common Limb Length Does Not Influence Weight Loss After Standard Laparoscopic Roux-En-Y Gastric Bypass

Background

Although Roux-en-Y gastric bypass (RYGBP) has proven its reliability over time in terms of weight loss and resolution of comorbidities, there continues to be a significant controversy in terms of used limb lengths. In the classical RYGBP, most surgeons have reported an alimentary limb length (ALL) of 100 to 150 cm and a bilio-pancreatic limb length (BPLL) of 50 to 75 cm. On the other hand, the common limb length (CLL) remains unknown in all the patients. As it is theoretically related to the level of malabsorption, CLL could influence weight loss after RYGBP.

Materials and Methods

We performed a laparoscopic RYGBP in 90 patients with a mean preoperative body mass index (BMI) of 44.8. ALL and BPLL were respectively fixed at 150 and 75 cm. A systematic intraoperative measurement of CLL was performed.

Results

As expected, we found a great variation of the jejuno-ileal length and also of the CLL. We created three subgroups of patients: one with the entire population, one excluding the super-obese patients (BMI?>?50) and the third one excluding the revisions. There was no statistically significant correlation between CLL and excess BMI loss (EBMIL) at 1, 3, 6 and 12 months of follow-up in each group. We also found a linear correlation between the jejuno-ileal length and the height of individuals.

Conclusion

With a fixed 150-cm ALL and a 75-cm BPLL, there is no evidence that the anatomical variations of CLL could influence weight loss after classical RYGBP.

     

Connexin 43 Is Necessary for Murine Tendon Enthesis Formation and Response to Loading

The enthesis is a mineralized fibrocartilage transition that attaches tendon to bone and is vital for musculoskeletal function. Despite recent studies demonstrating the necessity of muscle loading for enthesis formation, the mechanisms that regulate enthesis formation and mechanoresponsiveness remain unclear. Therefore, the current study investigated the role of the gap junction protein connexin 43 in these processes by deleting Gja1 (the Cx43 gene) in the tendon and enthesis. Compared with their wild-type (WT) counterparts, mice lacking Cx43 showed disrupted entheseal cell alignment, reduced mineralized fibrocartilage, and impaired biomechanical properties of the supraspinatus tendon entheses during postnatal development. Cx43-deficient mice also exhibited reduced ability to complete a treadmill running protocol but no apparent deficits in daily activity, metabolic indexes, shoulder muscle size, grip strength, and major trabecular bone properties of the adjacent humeral head. To examine enthesis mechanoresponsiveness, young adult mice were subjected to modest treadmill exercise. Gja1 deficiency in the tendon and enthesis reduced entheseal anabolic responses to treadmill exercise: WT mice had increased expression of Sox9, Ihh, and Gli1 and increased Brdu incorporation, whereas Cx43-deficient mice showed no changes or decreased levels with exercise. Collectively, the results demonstrated an essential role for Cx43 in postnatal tendon enthesis formation, function, and response to loading; results further provided evidence implicating a link between Cx43 function and the hedgehog signaling pathway. © 2020 American Society for Bone and Mineral Research.     

Skeletal muscle fibrosis and stiffness increase after rotator cuff tendon injury and neuromuscular compromise in a rat model

Rotator cuff tears can cause irreversible changes (e.g., fibrosis) to the structure and function of the injured muscle(s). Fibrosis leads to increased muscle stiffness resulting in increased tension at the rotator cuff repair site. This tension influences repairability and healing potential in the clinical setting. However, the micro‐ and meso‐scale structural and molecular sources of these whole‐muscle mechanical changes are poorly understood. Here, single muscle fiber and fiber bundle passive mechanical testing was performed on rat supraspinatus and infraspinatus muscles with experimentally induced massive rotator cuff tears (Tenotomy) as well as massive tears with chemical denervation (Tenotomy + BTX) at 8 and 16 weeks post‐injury. Titin molecular weight, collagen content, and myosin heavy chain profiles were measured and correlated with mechanical variables. Single fiber stiffness was not different between controls and experimental groups. However, fiber bundle stiffness was significantly increased at 8 weeks in the Tenotomy + BTX group compared to Tenotomy or control groups. Many of the changes were resolved by 16 weeks. Only fiber bundle passive mechanics was weakly correlated with collagen content. These data suggest that tendon injury with concomitant neuromuscular compromise results in extra‐cellular matrix production and increases in stiffness of the muscle, potentially complicating subsequent attempts for surgical repair. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1111–1116, 2014.     

Meta-analysis of retrojugular versus antejugular approach for carotid endarterectomy

Introduction

The retrojugular approach for carotid endarterectomy (CEA) has been reported to have the advantages of shorter operative time and ease of dissection, especially in high carotid lesions. Controversial opinion exists with regard to its safety and benefits over the conventional antejugular approach.

Methods

A systematic review of electronic information sources was conducted to identify studies comparing outcomes of CEA performed with the retrojugular and antejugular approach. Synthesis of summary statistics was undertaken and fixed or random effects models were applied to combine outcome data.

Findings

A total of 6 studies reporting on a total of 740 CEAs (retrojugular approach: 333 patients; antejugular approach: 407 patients) entered our meta-analysis models. The retrojugular approach was found to be associated with a higher incidence of laryngeal nerve damage (odds ratio [OR]: 3.21, 95% confidence interval [CI]: 1.46–7.07). No significant differences in the incidence of hypoglossal or accessory nerve damage were identified between the retrojugular and antejugular approach groups (OR: 1.09 and 11.51, 95% CI: 0.31–3.80 and 0.59–225.43). Cranial nerve damage persisting during the follow-up period was similar between the groups (OR: 2.96, 95% CI: 0.79–11.13). Perioperative stroke and mortality rates did not differ in patients treated with the retrojugular or antejugular approach (OR: 1.26 and 1.28, 95% CI: 0.31–5.21 and 0.25–6.50).

Conclusions

Currently, there is no conclusive evidence to favour one approach over the other. Proof from a well designed randomised trial would help determine the role and benefits of the retrojugular approach in CEA.     

Predictors of hemostatic failure after adrenaline injection in patients with peptic ulcers with non-bleeding visible vessel

BACKGROUND: Non-bleeding visible vessel (NBVV) in patients with bleeding peptic ulcer is associated with a high risk of rebleeding. The aim of this study was to define factors associated with failure of endoscopic hemostasis and rebleeding in patients with NBVV. METHODS: Clinical and endoscopic parameters related to failure of endoscopic hemostasis with adrenaline in 191 bleeding peptic ulcer patients with NBVV were evaluated. RESULTS: Endoscopic hemostasis was permanently successful in 154 patients (80.6%). Emergency surgical hemostasis for rebleeding was required in 37 patients (19.4%). Univariate analysis showed that therapeutic failure was significantly related to the presence of shock on admission (P=0.003), posterior duodenal ulcers (P=0.001), peptic ulcer history (P=0.001), previous peptic ulcer bleeding (P=0.002), or lack of history of non-steroidal anti-inflammatory drugs consumption, when compared to use of such drugs (P=0.04). Patients where therapy failed had lower hemoglobin levels at admission (7.8+/-1.9 g/dL versus 10+/-2.4 g/dL, P=0.005). In a multivariate analysis low hemoglobin (P<0.001) as well as history of previous peptic ulcer bleeding (P=0.002) and posterior duodenal ulcers (P=0.001) were negative predictors. Using the mean value of hemoglobin as the cut-off point, it is noteworthy that only 2 out of 81 patients (2.5%) who had none of these predictive factors required emergency surgical hemostasis, whereas 34 out of 110 patients (30.9%) with at least one predictive factor required emergency surgery. CONCLUSION: It is possible, by employing specific characteristics, to define a subgroup of high-risk patients for rebleeding in patients with NBVV despite therapeutic endoscopy and thus candidates for a complementary endoscopic method of hemostasis or emergency surgical intervention.     

Potential role of hepatic progenitor cells expression in cases of chronic hepatitis C and their relation to response to therapy: a clinicopathologic study.

BACKGROUND: This study investigates the correlation of hepatic progenitor cells (HPC) expression with treatment response in patients with chronic hepatitis C. DESIGN: The study comprised 77 liver biopsies with chronic hepatitis C (HCV). All patients were PCR-HCV (+) and received antiviral therapy with interferon or pegylated interferon alpha-2b and ribavirin. Twenty-nine patients were assigned as responders (group A), 29 as nonresponders (group B) and 19 as relapsers (group C). Ten normal liver biopsies were used as controls. Liver paraffin sections were subjected (a) to immunohistochemistry using antibodies for cytokeratins 19 (CK19) and 7 (CK7), alpha-fetoprotein (AFP), leukocyte common antigen (LCA) and CD34 antigen (b) to in situ hybridization for AFP mRNA and (c) to immunohistochemistry+in situ hybridization. Results were expressed as % of positive cells following morphometric analysis. RESULTS: HPC expression was present in all 87 specimens. In the control biopsies, rare HPC were detected. In the CH cases and according to AFP mRNA expression, the grade for % HPC expression was: group B: 53.2+/-2.6> group C: 48.37+/-1.8> group A: 31.4+/-1.6 (group A vs B P<0.01, group A vs C P<0.01, group B vs C P>0.05. Double stain revealed that HPC coexpressed CK19/AFP mRNA, CK7/AFP mRNa and AFP protein/AFP mRNA. HPC-percentages were directly correlated with total HAI score (P<0.01), fibrosis stage (P<0.01), and transaminase values (P<0.05). CONCLUSIONS: This study demonstrates that in cases of chronic hepatitis C, the significant association of HPC expression with the severity of disease and more specifically with the response to treatment implies that HPC development and proliferation may provide additional prognostic information and predict prognosis in such cases.