Late Dissection of Pulmonary Autograft Treated by Valve-Sparing Aortic Root Replacement

Abstract   Dissection of the pulmonary autograft is an extremely rare complication requiring emergent treatment as there is a chance of rupture and proximal aortic involvement. The autograft dissection can involve the aortic annulus, causing separation of leaflets from the annulus in addition to causing annular dilatation, thereby precluding resuspension of leaflets. The usual treatment in such cases is to perform the Bentall procedure, which involves placing a valved conduit (usually mechanical valve) and thereby necessitating anticoagulation. This report describes a case of successful valve-sparing aortic root replacement following the Ross procedure with dissection of autograft.     

Role of Periductal and Ductular Epithelial Cells of the Adult Rat Pancreas in Pancreatic Hepatocyte Lineage: A Change in the Differentiation Commitment

Development of pancreatic hepatocytes in adult rats maintained on copper deficient diet containing 0.6% trien (CuDT) has been reported recently. To elucidate the histogenesis of hepatocytes a sequential study was undertaken using morphologic, histochemical, immunochemical, in situ hybridization, and Northern blot analysis. Male F-344 rats weighing 80 to 90 g were fed CuDT for 8 weeks and returned to normal rat chow. Beginning from 4 weeks of copper depletion, there was a progressive loss of acinar cells and by 8 weeks more than 90% of the acinar tissue was lost. During this period, there was an increase in the number of adipocytes in the interstitium, and in the number of interstitial and ductular cells. Morphologic observations were confirmed by immunoblot and Northern blot analysis, in which the amount of pancreatic proteins and their mRNAs decreased between 5 and 8 weeks. During this period, a progressive increase in the level of albumin mRNA was observed. In situ hybridization, performed at 7 weeks of copper deficiency, showed localization of albumin mRNA over interstitial and ductular cells. Pancreatic hepatocytes were identified immediately after the rats were returned to a normal diet and gradually increased in number. The hepatocytes occupied almost 60% of the pancreatic volume by 8 weeks. During the early recovery phase, hepatocytes were identified in ductules as well as in the interstitium. Based on these studies, it is concluded that both the ductular cells and interstitial cells, which resemble oval cells of liver, are capable of transforming into pancreatic hepatocytes and these cells may be considered stem-cell equivalent.     

Demineralization and ion binding action of polycarboxylate cement liquid on human dental enamel

The demineralization and ion binding effects on dental tissues due to poly(acrylic) acid attack under different dilution conditions of the latter are studied by scanning electron microscope (SEM) and infrared (IR) spectroscopy. The results indicate that in addition to the general demineralization effects such as preferential prism core attack, prism periphery attack, and protruding prism rods, competing ion binding effects also occur. Using optimum dilution conditions, the microstructural effects of demineralization and ion binding are shown and the effects are related to IR spectral observations.     

Induction of natural IgE by glucocorticoids

IgE mediates allergic responses by coating mast cell or basophil surfaces and inducing degranulation upon binding a specific allergen. IgE can also be spontaneously produced in the absence of foreign allergens; yet the origin, regulation, and functions of such “natural” IgE still remain largely unknown. Here, we find that glucocorticoids enhance the production of IgE in B cells both in vivo and ex vivo without antigenic challenge. Such IgE production is promoted by B cell–intrinsic glucocorticoid receptor signaling that reinforces CD40 signaling and synergizes with the IL-4/STAT6 pathway. In addition, we found that rare B cells in the mesenteric lymph nodes are responsible for the production of glucocorticoid-inducible IgE. Furthermore, locally produced glucocorticoids in the gut may induce natural IgE during perturbations of gut homeostasis, such as dysbiosis. Notably, mice preemptively treated with glucocorticoids were protected from subsequent pathogenic anaphylaxis. Together, our results suggest that glucocorticoids, classically considered to be broadly immunosuppressive, have a selective immunostimulatory role in B cells.     

Predictors of acquired lipodystrophy in juvenile-onset dermatomyositis and a gradient of severity

We describe the clinical features of 28 patients with juvenile dermatomyositis (JDM) and 1 patient with adult-onset dermatomyositis (DM), all of whom developed lipodystrophy (LD) that could be categorized into 1 of 3 phenotypes, generalized, partial, or focal, based on the pattern of fat loss distribution. LD onset was often delayed, beginning a median of 4.6 years after diagnosis of DM. Calcinosis, muscle atrophy, joint contractures, and facial rash were DM disease features found to be associated with LD. Panniculitis was associated with focal lipoatrophy while the anti-p155 autoantibody, a newly described myositis-associated autoantibody, was more associated with generalized LD. Specific LD features such as acanthosis nigricans, hirsutism, fat redistribution, and steatosis/nonalcoholic steatohepatitis were frequent in patients with LD, in a gradient of frequency and severity among the 3 sub-phenotypes. Metabolic studies frequently revealed insulin resistance and hypertriglyceridemia in patients with generalized and partial LD. Regional fat loss from the thighs, with relative sparing of fat loss from the medial thighs, was more frequent in generalized than in partial LD and absent from DM patients without LD. Cytokine polymorphisms, the C3 nephritic factor, insulin receptor antibodies, and lamin mutations did not appear to play a pathogenic role in the development of LD in our patients. LD is an under-recognized sequela of JDM, and certain DM patients with a severe, prolonged clinical course and a high frequency of calcinosis appear to be at greater risk for the development of this complication. High-risk JDM patients should be screened for metabolic abnormalities, which are common in generalized and partial LD and result in much of the LD-associated morbidity. Further study is warranted to investigate the pathogenesis of acquired LD in patients with DM.     

Associations Between Abortion Services and Acceptance of Postabortion Contraception in Six Indian States

Women receiving induced abortions or postabortion care are at high risk of subsequent unintended pregnancy, and intervals of less than six months between abortion and subsequent pregnancy may be associated with adverse outcomes. This study highlights the prevalence and attributes of postabortion contraceptive acceptance from 2,456 health facilities in six major Indian states, among 292,508 women who received abortion care services from July 2011 through June 2014. Eighty‐one percent of the women accepted postabortion contraceptive methods: 53 percent short‐term, 11 percent intrauterine devices, and 16 percent sterilization. Postabortion contraceptive acceptance was highest among women who were aged 25 years and older, received first‐trimester services, received induced abortion, attended primary‐level health facilities, and had medical abortions. Doctors receiving post‐training support were more likely to offer contraceptives, but no association was observed between such support and acceptance of IUDs or sterilization. Comprehensive service‐delivery interventions, including ensuring availability of skilled providers and contraceptive commodities, offering clinical mentoring for providers, identifying and addressing provider bias, and improving provider counseling skills, can increase postabortion contraceptive acceptance and reduce unintended pregnancy.