Rotator Cuff Fibro-Adipogenic Progenitors Demonstrate Highest Concentration,Proliferative Capacity,and Adipogenic Potential Across Muscle Groups

Fatty infiltration (FI) of rotator cuff (RC) muscles is common in patients with RC tears. Studies have demonstrated that fibro-adipogenic progenitors (FAPs), a population of resident muscle stem cells, are the main contributors of FI, which adversely affects muscle quality and RC repair success. Although FI is common in RC injuries, it is not frequently reported after other musculotendinous injuries. Additionally, studies have shown the development of different pathology patterns across muscle groups suggestive of intrinsic differences in cellular composition and behavior. This study evaluates FAP distribution and differentiation properties across anatomic locations in mice. Muscles from seven different anatomic locations were harvested from PDGFRα-eGFP FAP reporter mice. FAPs were quantified using histology and FACS sorting with BD Aria II with CD31⁻/CD45⁻/Integrinα7⁻/Sca-1⁺ and PDGFRα reporter signal (n = 3 per muscle). The cells were analyzed for adipogenesis using immunocytochemistry and for proliferation properties with Brdu-Ki67 staining. In a separate group of mice, RC and tibialis anterior muscles received glycerol injection and were harvested after 2 weeks for FI quantification (n = 4). One-way analysis of variance was used for statistical comparisons among groups, with significance at p < 0.05. FAPs from the RC, masseter, and paraspinal muscles were more numerous and demonstrated greater proliferative capacity and adipogenic potency than those from the tibialis anterior and gastrocnemius. The RC demonstrated significantly greater levels of FI than the tibialis anterior after glycerol-injection injury. Clinical Significance: This study suggests differences in FAP distribution and differentiation characteristics may account for the propensity to develop FI in RC tears as compared with other musculotendinous injuries. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1113-1121, 2020     

Mycotoxin Cocktail in the Samples of Oilseed Cake from Early Maturing Cotton Varieties Associated with Cattle Feeding Problems

Cottonseed cake in South East Asia has been associated with health issues in ruminants in the recent years. The present study was carried out to investigate the health issues associated with cottonseed cake feeding in dairy animals in Pakistan. All the cake samples were confirmed to be from early maturing cotton varieties (maturing prior to or during Monsoon). A survey of the resource persons indicated that the feeding problems with cottonseed cake appeared after 4–5 months of post-production storage. All the cake samples had heavy bacterial counts, and contaminated with over a dozen different fungal genera. Screening for toxins revealed co-contamination with toxic levels of nearly a dozen mycotoxins including aflatoxin B₁ + B₂ (556 to 5574 ppb), ochratoxin A + B (47 to 2335 ppb), cyclopiazonic acid (1090 to 6706 ppb), equisetin (2226 to 12672 ppb), rubrofusarin (81 to 1125), tenuazonic acid (549 to 9882 ppb), 3-nitropropionic acid (111 to 1032 ppb), and citrinin (29 to 359 ppb). Two buffalo calves in a diagnostic feed trial also showed signs of complex toxicity. These results indicate that inappropriate processing and storage of the cake, in the typical conditions of the subcontinent, could be the main contributory factors regarding the low quality of cottonseed cake.     

Gap phenomenon in the bundle of his conduction]

His bundle electrograms recorded during atrial stimulation with the extrastimulus technique permitted the analysis of the so called gaps in bundle branch conduction. Three different types of gaps were identified each with a distinct electrophysiological mechanism. In type I gap a CLBBB pattern disappeared at shorter coupling (A1-A2) intervals because the more premature impulses encountered a greater degree of the delay at the A-V node therefore reaching the left bundle branch after its effective refractory period had ended. During this part of the cycle the H1-H2 were longer and H2-V2 intervals shorter than when CRBBB was present. In type II gap a CRBBB pattern disappeared at shorter coupling intervals because the premature impulses met a greater delay in the proximal portions of the His-Purkinje system. In consequence, they arrived at the right bundle branch when its effective refractory period had expired. When this occurred the H1-H2 interval were shorter and the H2-V2 longer than those at which CRBBB had been present. The patient with type III gap had CLBBB. A-V conduction was possible through the right bundle branch very late in the cycle. However, it could not occur at shorter coupling intervals finally reappearing at even shorter coupling intervals. True supernormal conduction or vagal pulsatile discharges could have been present. Yet, we favor, as the most likely possibility, the existence of 2:1 phase 4 block with latent or abortive escapes not recorded in the surface leads.