Extramural Coronary Artery Disease in Type I Diabetes Mellitus: A Quantative Autopsy Study

Author Institution: Departments of Pathology and Internal Medicine, College of Medicine, University of CincinnatiExtramural coronary arteries of 17 type I diabetics and 22 control patients were examined at necropsy following a detailed methodology plan. There was a greater extent of luminal narrowing in the extramural coronary arteries in the diabetic patients than in the controls. While it is known that in patients with the advanced stage of type I diabetes mellitus significant coronary atherosclerosis is likely to be present, it is new information that they have a propensity for obstructive atherosclerosis, not just in the 3 major coronary arteries but also in the branches. Young type I diabetics with atherosclerosis of proximal portions of the coronary vasculature are likely to have equally severe atherosclerosis in the distal portions and branches as well. Atherosclerosis was less severe in the diabetic patients who did receive hemodialysis and/or a renal transplant than those who did not

Search for dark mesons decaying to top and bottom quarks in proton-proton collisions at √s = 13 TeV with the ATLAS detector

A search for dark mesons originating from strongly-coupled, SU(2) dark favor symmetry conserving models and decaying gaugephobically to pure Standard Model final states containing top and bottom quarks is presented. The search targets fully hadronic final states and final states with exactly one electron or muon and multiple jets. The analyzed data sample corresponds to an integrated luminosity of 140 fb−1 of proton-proton collisions collected at √s = 13 TeV with the ATLAS detector at the Large Hadron Collider. No significant excess over the Standard Model background expectation is observed and the results are used to set the first direct constraints on this type of model. The two-dimensional signal space of dark pion masses mπD and dark rho-meson masses mρD is scanned. For mπD /mρD = 0.45, dark pions with masses mπD < 940 GeV are excluded at the 95% CL, while for mπD /mρD = 0.25 masses mπD < 740 GeV are excluded

Combination of searches for Higgs boson decays into a photon and a massless dark photon using pp collisions at √s = 13 TeV with the ATLAS detector

A combination of searches for Higgs boson decays into a visible photon and a massless dark photon (H → γγd) is presented using 139 fb−1 of proton-proton collision data at a centre-of-mass energy of √s = 13 TeV recorded by the ATLAS detector at the Large Hadron Collider. The observed (expected) 95% confidence level upper limit on the Standard Model Higgs boson decay branching ratio is determined to be B(H → γγd) < 1.3% (1.5)%. The search is also sensitive to higher-mass Higgs bosons decaying into the same final state. The observed (expected) 95% confidence level limit on the cross-section times branching ratio ranges from 16 fb (20 fb) for mH = 400 GeV to 1.0 fb (1.5 fb) for mH = 3 TeV. Results are also interpreted in the context of a minimal simplified model

The surgical pathology of rheumatic and floppy mitral valves. Distinctive morphologic features upon gross examination

A total of 30 surgically resected complete mitral valves were examined, without prior knowledge of the clinical history, to evaluate the reliability of gross inspection only for the correct morphological diagnosis. Twenty valves were rheumatic; 10 were obtained from patients with idiopathic mitral valve prolapse. Two groups were identified: group I correlated with a rheumatic history; group II showed floppy mitral valves, which correlated with mitral valve prolapse. Hence, it is considered that the diagnosis of rheumatic or floppy mitral valve can be established accurately upon gross examination only. The rheumatic valve is fibrotic and firm, leading to thickening and fusion of leaflets and commissures. Narrowing and lowering of the "principal" ostium occurs. This results in a funnel-shaped valve, which is further accentuated by interchordal fusion. Rigidity is its hallmark. Chordal rupture is unlikely. Calcification can be found anywhere in the valve. Hooding is extremely unusual. The floppy valve, by contrast, shows laxity of leaflets, which may lead to the formation of dome-like deformities reaching above the level of the annulus. The chordae are often thin, attenuated, and may have ruptured. The distribution of chordae and mode of anchoring is often chaotic. Fibrosis occurs mainly at the anchoring sites of the chordae underneath or at the margin of the leaflet, or where previously ruptured, intertwined chordae are plastered underneath the dome. Fibrosis is further aggravated at the margins and atrial surface of the leaflets because of regurgitant friction. In spite of fibrosis, the floppy valve remains soft and flexible. Commissural fusion is absent. Interchordal fusion is not a characteristic feature of the floppy mitral valve. Gross inspection will not only correctly discriminate between a rheumatic and floppy mitral valve, but may also contribute to an understanding of the pathogenesis of the valve deformit

Isolated mitral valve prolapse: chordal architecture as an anatomic basis in older patients

Ten patients with an average age of 58 years underwent valve replacement because of isolated mitral valve prolapse with severe regurgitation. None had clinical evidence of Marfan's syndrome or another systemic disease that would indicate that a primary connective tissue disorder was the cause of the prolapse. All 10 patients had a dome configuration of the posterior leaflet and one or more ruptured chordae related to it. The gross morphology of the resected specimens revealed marked deviations in chordal branching and the pattern of anchoring in each of the 10 cases, rendering the most severely affected parts of the leaflets less well supported. Similar changes occurred at sites remote from the principal abnormality. Microscopically, the dominant tissue change was myxomatous transformation within the affected leaflets and chordae with secondary changes at both atrial and ventricular surfaces. These findings could indicate that insufficient chordal support may have promoted the development of the floppy valve through a process of chronic undue and unbalanced stress on the valve tension and closure apparatus. The resultant degeneration of the connective tissues, histologically expressed as myxomatous transformation, may underlie stretching and thus redundance of the leaflets and eventually rupture of chordae. It is suggested that this sequence of events be considered as a possible pathogenetic mechanism of isolated mitral valve prolapse, particularly in the subset of aged patient