Targeting T cell (oxidative) metabolism to improve immunity to viral infection in the context of obesity

Disorders of systemic metabolism can influence immunity. Individuals with obesity are known to have increased inflammation, increased risk to select autoimmune diseases, impaired response to several infections, and impaired vaccine response. For example, over the last decade, it has become clear that individuals with obesity have increased risk of morbidity and mortality from influenza infection. Unsurprisingly, this finding is also observed in the current COVID-19 pandemic: individuals with obesity, particularly severe obesity, have increased risk of poor outcomes from SARS-CoV-2 infection, including increased rates of hospitalization, ICU admission, mechanical ventilation, and death. Several studies have now demonstrated a critical role for T cells in the context of obesity-associated immune dysfunction in response to viral infection, and one mechanism for this may be altered T cell metabolism. Indeed, recent studies have shown that activated T cells from obese mice have an altered metabolic profile characterized by increased glucose oxidation, both in vitro and in vivo following viral infection. For that reason, treatments that target abnormal immune cell metabolism in obesity may improve outcomes to viral infection. To that end, several recent studies have shown that use of the metabolic drug, metformin, can reverse abnormal T cell metabolism and restore T cell immunity, as well as survival, in response to viral infection. These findings will be discussed in detail here

The Use of Bovine Pericardial Buttress on Linear Stapler Fails to Reduce Pancreatic Fistula Incidence in a Porcine Pancreatic Transection Model

We investigate the effectiveness of buttressing the surgical stapler to reduce postoperative pancreatic fistulae in a porcine model. As a pilot study, pigs (n = 6) underwent laparoscopic distal pancreatectomy using a standard stapler. Daily drain output and lipase were measured postoperative day 5 and 14. In a second study, pancreatic transection was performed to occlude the proximal and distal duct at the pancreatic neck using a standard stapler (n = 6), or stapler with bovine pericardial strip buttress (n = 6). Results. In pilot study, 3/6 animals had drain lipase greater than 3x serum on day 14. In the second series, drain volumes were not significantly different between buttressed and control groups on day 5 (55.3 ± 31.6 and 29.3 ± 14.2 cc, resp.), nor on day 14 (9.5 ± 4.2 cc and 2.5 ± 0.8 cc, resp., P = 0.13). Drain lipase was not statistically significant on day 5 (3,166 ± 1,433 and 6,063 ± 1,872 U/L, resp., P = 0.25) or day 14 (924 ± 541 and 360 ± 250 U/L). By definition, 3/6 developed pancreatic fistula; only one (control) demonstrating a contained collection arising from the staple line. Conclusion. Buttressed stapler failed to protect against pancreatic fistula in this rigorous surgical model

The end of the unique myocardial band: Part I. Anatomical considerations

The concept of the ‘unique myocardial band’, which proposes that the ventricular myocardial cone is arranged like skeletal muscle, provides an attractive framework for understanding haemodynamics. The original idea was developed by Francisco Torrent-Guasp. Using boiled hearts and blunt dissection, Torrent-Guasp created a single band of ventricular myocardium extending from the pulmonary trunk to the aortic root, with the band thus constructed encircling both ventricular cavities. Cooked hearts can, however, be dissected in many ways. In this review, we show that the band does not exist as an anatomical entity with defined borders. On the contrary, the ventricular cardiomyocytes are aggregated end to end and by their branching produce an intricate meshwork. Across the thickness of the left ventricular wall, the chains of cardiomyocytes exhibit a gradually changing helical angle, with a circumferential zone formed in the middle. There is no abrupt change in helical angle, as could be expected if the wall was constructed of opposing limbs of a single wrapped band, nor does the long axis of the cardiomyocytes consistently match with the long axis of the unique myocardial band. There are, furthermore, no connective tissue structures that could be considered to demarcate its purported boundaries. The unique myocardial band should be consistent with evolution, and although the ventricular wall of fish and reptiles has one or several distinct layers, a single band is not found. In 1965, Lev and Simpkins cautioned that the ventricular muscle mass of a cooked heart can be dissected almost at the whim of the anatomist. We suggest that the unique myocardial band should have ended there

The Thermophilic Actinomycetes in mouldy hay

Taxonomic studies on the thermophilic oligosporic actinomycete chiefly responsible for the respiratory disease Farmer’s Lung support the view that the organism was incorrectly identified as Thermopolyspora polyspora Hens. The organism belongs to the genus Micropolyspora Lechevalier et al. and is described as a new species Micropolyspora faeni. RESP-575

Insights from echocardiography, magnetic resonance imaging, and microcomputed tomography relative to the mid-myocardial left ventricular echogenic zone.

Background: The anatomical substrate for the mid-mural ventricular hyperechogenic zone remains uncertain, but it may represent no more than ultrasound reflected from cardiomyocytes orientated orthogonally to the ultrasonic beam. We sought to ascertain the relationship between the echogenic zone and the orientation of the cardiomyocytes. Methods: We used 3D echocardiography, diffusion tensor imaging, and microcomputed tomography to analyze the location and orientation of cardiomyocytes within the echogenic zone. Results: We demonstrated that visualization of the echogenic zone is dependent on the position of the transducer and is most clearly seen from the apical window. Diffusion tensor imaging and microcomputed tomography show that the echogenic zone seen from the apical window corresponds to the position of the circumferentially orientated cardiomyocytes. An oblique band seen in the parasternal view relates to cardiomyocytes orientated orthogonally to the ultrasonic beam. Conclusions: The mid-mural ventricular hyperechogenic zone represents reflected ultrasound from cardiomyocytes aligned orthogonal to the ultrasonic beam. The echogenic zone does not represent a space, a connective tissue sheet, a boundary between ascending and descending limbs of a hypothetical helical ventricular myocardial band, nor an abrupt change in cardiomyocyte orientation