Tendon Is Covered by a Basement Membrane Epithelium That Is Required for Cell Retention and the Prevention of Adhesion Formation

The ability of tendons to glide smoothly during muscle contraction is impaired after injury by fibrous adhesions that form between the damaged tendon surface and surrounding tissues. To understand how adhesions form we incubated excised tendons in fibrin gels (to mimic the homeostatic environment at the injury site) and assessed cell migration. We noticed cells exiting the tendon from only the cut ends. Furthermore, treatment of the tendon with trypsin resulted in cell extravagation from the shaft of the tendons. Electron microscopy and immunolocalisation studies showed that the tendons are covered by a novel cell layer in which a collagen type IV/laminin basement membrane (BM) overlies a keratinised epithelium. PCR and western blot analyses confirmed the expression of laminin β1 in surface cells, only. To evaluate the cell retentive properties of the BM in vivo we examined the tendons of the Col4a1+/Svc mouse that is heterozygous for a G-to-A transition in the Col4a1 gene that produces a G1064D substitution in the α1(IV) chain of collagen IV. The flexor tendons had a discontinuous BM, developed fibrous adhesions with overlying tissues, and were acellular at sites of adhesion formation. In further experiments, tenotomy of wild-type mice resulted in expression of laminin throughout the adhesion. In conclusion, we show the existence of a novel tendon BM-epithelium that is required to prevent adhesion formation. The Col4a1+/Svc mouse is an effective animal model for studying adhesion formation because of the presence of a structurally-defective collagen type IV-containing BM

Anatomy of the Breast Fascial System: A Systematic Review of the Literature

Background: Understanding the anatomy of the fascial and ligamentous structures of the breast is important in both aesthetic and reconstructive breast surgery. Several structures have been identified that play a significant role in the aesthetic qualities and support of the breast warranting consideration in the context of breast reconstruction. Methods: The authors performed a systematic review of anatomical, clinical, histologic, and radiologic studies that have described, characterized, and named these structures. The authors have summarized and critically appraised prior research to clarify and define the key fascial structures of the breast, their anatomical function, and their clinical significance in aesthetic and reconstructive breast surgery. Results: Through their review, six distinct breast fascial structures were encountered consistently in the literature. The authors have organized them into intraglandular and extraglandular structures and have reviewed their significance in the context of reconstructive breast surgery. Conclusions: The primary fascial structures of the breast are important anatomical landmarks with numerous clinical applications. Cooper ligaments divide the breast parenchyma. The superficial and deep layers of the superficial fascia encase the breast in a “pocket,” condensing into one thickened layer of fascia along the peripheral breast footprint. The inframammary fold supports and defines the inferior pole. The horizontal septum is a reliable neurovascular landmark. The vertical septum is a newly discovered fascial structure. There are certainly clinical implications that have yet to be described because of the relatively limited and disputed information on the fascia of the female breast and, ultimately, more research is warranted

The Shame–Blame Game: Is It Still Necessary? A National Survey of Shame-based Teaching Practice in Canadian Plastic Surgery Programs

Background:. As understanding of poor physician mental health and burnout strengthens, it is becoming important to identify factors that detract from wellbeing. Shame-based learning (SBL) is detrimental to psychological health and can contribute to burnout, substance abuse and suicide. This study endeavoured to quantify the unknown prevalence and effects of SBL in Canadian plastic surgery programs. Methods:. An electronic survey was sent to all attending surgeons and trainee (residents and fellows) members of the Canadian Society of Plastic Surgeons. SBL was assessed using a validated questionnaire. Data was analyzed using descriptive statistics and thematic analysis. Results:. 98 responses (14.7%) comprising of 63 attending surgeons and 36 trainees were received. The majority of attending surgeons (78 percent) and trainees (67%) have been shamed. Fourteen percent of trainees and 9% of attending surgeons felt that SBL is necessary. The most common event provoking shaming for trainees was wrong answers (56%) and for attending surgeons was disagreement in clinical care (21%). For both groups, shamers were in positions of authority. The most common effect of SBL in trainees was a loss of self-confidence (53%), compared to no negative effect in attending surgeons (49 percent). Thirty-nine percent of trainees dealt with shaming events with support from fellow trainees (39 percent), while attending surgeons kept it to themselves (40 percent). Conclusion:. SBL is present in Canadian plastic surgery residency programs and has numerous detrimental effects. To foster better mental health, residency programs should identify ongoing SBL and make efforts to transition to healthier feedback strategies

Development of a clinical risk score to predict death in patients with COVID-19

Objective: To build a clinical risk score to aid risk stratification among hospitalised COVID-19 patients. Methods: The score was built using data of 417 consecutive COVID-19 in patients from Kuwait. Risk factors for COVID-19 mortality were identified by multivariate logistic regressions and assigned weighted points proportional to their beta coefficient values. A final score was obtained for each patient and tested against death to calculate an Receiver-operating characteristic curve. Youden's index was used to determine the cut-off value for death prediction risk. The score was internally validated using another COVID-19 Kuwaiti-patient cohort of 923 patients. External validation was carried out using 178 patients from the Italian CoViDiab cohort. Results: Deceased COVID-19 patients more likely showed glucose levels of 7.0–11.1 mmol/L (34.4%, p < 0.0001) or >11.1 mmol/L (44.3%, p < 0.0001), and comorbidities such as diabetes and hypertension compared to those who survived (39.3% vs. 20.4% [p = 0.0027] and 45.9% vs. 26.6% [p = 0.0036], respectively). The risk factors for in-hospital mortality in the final model were gender, nationality, asthma, and glucose categories (<5.0, 5.5–6.9, 7.0–11.1, or 11.1 > mmol/L). A score of ≥5.5 points predicted death with 75% sensitivity and 86.3% specificity (area under the curve (AUC) 0.901). Internal validation resulted in an AUC of 0.826, and external validation showed an AUC of 0.687. Conclusion: This clinical risk score was built with easy-to-collect data and had good probability of predicting in-hospital death among COVID-19 patients