Constrictive pericarditis in the new millennium.

Constrictive pericarditis (CP) is a complex clinical syndrome in which an inflamed pericardium becomes fibrotic and non-compliant, ultimately reducing cardiac pump performance. Although we have known about CP for centuries, it remains a challenge to diagnose. Recent advances in cardiac imaging, along with an expanding armamentarium of treatment options, have improved the quality and precision of care for patients with CP. This article reviews important historical and contemporary perspectives on the pathophysiology of CP, as well as our approach to diagnosis and management.

Diffuse Large B-Cell Lymphoma Mimicking Intramural Hematoma of the Thoracic Aorta.

Diffuse large B-cell lymphoma (DLBCL) is an aggressive lymphoma that is fatal if left untreated. Few cases have been reported of involvement of the aorta. Here we present a case of DLBCL that was diagnosed by periaortic computed tomography-guided biopsy. (Level of Difficulty: Intermediate.).

Cardiovascular services in Covid-19 - Impact of the pandemic and lessons learned.

The coronavirus disease 2019 (COVID-19) pandemic immediately and perhaps irrevocably impacted society at large, the provision of cardiovascular (CV) care, the function and staffing of hospitals, and CV clinicians. Initially many clinicians at all career stages rose to the challenges, and support and accolades were the initial societal response. Politicization of the public health response as well as widespread misinformation and disinformation all negatively impacted CV clinicians' roles as well diminished and, in some cases, eliminated their public and self-esteem. Unabated stress, disrespect, and a likely lack of emotional and physical respite may all have contributed to the Great Resignation. Insights gained from review of the COVID-19 pandemic may help inform changes to foster system resiliency and prepare for an improved response to the inevitable next stressor.

Similar Biophysical Abnormalities in Glomeruli and Podocytes from Two Distinct Models.

Background FSGS is a pattern of podocyte injury that leads to loss of glomerular function. Podocytes support other podocytes and glomerular capillary structure, oppose hemodynamic forces, form the slit diaphragm, and have mechanical properties that permit these functions. However, the biophysical characteristics of glomeruli and podocytes in disease remain unclear.Methods Using microindentation, atomic force microscopy, immunofluorescence microscopy, quantitative RT-PCR, and a three-dimensional collagen gel contraction assay, we studied the biophysical and structural properties of glomeruli and podocytes in chronic (Tg26 mice [HIV protein expression]) and acute (protamine administration [cytoskeletal rearrangement]) models of podocyte injury.Results Compared with wild-type glomeruli, Tg26 glomeruli became progressively more deformable with disease progression, despite increased collagen content. Tg26 podocytes had disordered cytoskeletons, markedly abnormal focal adhesions, and weaker adhesion; they failed to respond to mechanical signals and exerted minimal traction force in three-dimensional collagen gels. Protamine treatment had similar but milder effects on glomeruli and podocytes.Conclusions Reduced structural integrity of Tg26 podocytes causes increased deformability of glomerular capillaries and limits the ability of capillaries to counter hemodynamic force, possibly leading to further podocyte injury. Loss of normal podocyte mechanical integrity could injure neighboring podocytes due to the absence of normal biophysical signals required for podocyte maintenance. The severe defects in podocyte mechanical behavior in the Tg26 model may explain why Tg26 glomeruli soften progressively, despite increased collagen deposition, and may be the basis for the rapid course of glomerular diseases associated with severe podocyte injury. In milder injury (protamine), similar processes occur but over a longer time.

Identification of novel mouse genes conferring posthypoxic pauses.

Although central to the susceptibility of adult diseases characterized by abnormal rhythmogenesis, characterizing the genes involved is a challenge. We took advantage of the C57BL/6J (B6) trait of hypoxia-induced periodic breathing and its absence in the C57BL/6J-Chr 1(A/J)/NaJ chromosome substitution strain to test the feasibility of gene discovery for this abnormality. Beginning with a genetic and phenotypic analysis of an intercross study between these strains, we discovered three quantitative trait loci (QTLs) on mouse chromosome 1, with phenotypic effects. Fine-mapping reduced the genomic intervals and gene content, and the introgression of one QTL region back onto the C57BL/6J-Chr 1(A/J)/NaJ restored the trait. mRNA expression of non-synonymous genes in the introgressed region in the medulla and pons found evidence for differential expression of three genes, the highest of which was apolipoprotein A2, a lipase regulator; the apo a2 peptide fragment (THEQLTPLVR), highly expressed in the liver, was expressed in low amounts in the medulla but did not correlate with trait expression. This work directly demonstrates the impact of elements on mouse chromosome 1 in respiratory rhythmogenesis.