Preparative purification of the rat mast cell chymase. Characterization and Interaction with granule components

The rat mast cell granule chymotrypsinlike enzyme was purified to homogeneity from 1 M NaCl solubilized membrane and granule-rich fractions of concentrated rat peritoneal mast cells by a preparative technique utilizing chromatography on Dowex 1, filtration on Sephadex G-75, and affinity chromatography with D-tryptophan methyl ester. Acid disk gel electrophoresis of the purified chymase disclosed a single stained band with activity being eluted from a replicate sliced gel in the same region. SDS-polyacrylamide gel electrophoresis of purified protein gave a single stained band that did not change in position with reduction and alkylation. Mast cell chymase is thus a cationic protein of 25,000 mol wt composed of a single polypeptide chain. The apparent K(m) of the chymase for BTEE was 1.5 x 10(-3) M and the V(max) was 67.8 μmol/min per mg. The enzyme was inhibited by TPCK and not by TLCK. The chymase complexed with native macromolecular rat mast cell heparin in molar ratios of 12:1 and 16:1, and complete heparin uptake occurred at a 40:1 ratio of chymase to heparin. Chymase activity was partially masked by combination with heparin in the isolated granule or experimental chymase-heparin complex, and soluble purified chymase was inhibited by concentrations of 5-HT comparable to those present in mast cells. It is therefore possible that the active site of chymase in the mast cell granule is largely masked by the combined effects of macromolecular heparin and 5-HT.     

Adherence to secondary prophylaxis and disease recurrence in 536 Brazilian children with rheumatic fever

Background  

More than 15 million people worldwide have rheumatic fever (RF) and rheumatic heart disease due to RF. Secondary prophylaxis is a critical cost-effective intervention for preventing morbidity and mortality related to RF. Ensuring adequate adherence to secondary prophylaxis for RF is a challenging task. This study aimed to describe the rates of recurrent episodes of RF, quantify adherence to secondary prophylaxis, and examine the effects of medication adherence to the rates of RF in a cohort of Brazilian children and adolescents with RF.     

Serum 25-hydroxyvitamin D3 concentrations and carotid artery intima-media thickness among type 2 diabetic patients

OBJECTIVE: To estimate the prevalence of hypovitaminosis D among type 2 diabetic adults and to assess the relationship between hypovitaminosis D and intimal medial thickening (IMT) of the common carotid artery, a marker of preclinical atherosclerosis. DESIGN, PATIENTS AND MEASUREMENTS: We compared winter serum 25-hydroxyvitamin D3 [25(OH)D] concentrations in 390 consecutive type 2 diabetic patients and 390 nondiabetic controls who were comparable for age and sex. Common carotid IMT was measured with ultrasonography only in diabetic patients by a single trained operator blinded to subjects' details. RESULTS: The prevalence of hypovitaminosis D (i.e. 25(OH)D 相似文献   

Relations between carotid artery wall thickness and liver histology in subjects with nonalcoholic fatty liver disease

OBJECTIVE: Nonalcoholic fatty liver disease (NAFLD) is closely associated with several metabolic syndrome features. We assessed whether NAFLD is associated with carotid artery intima-media thickness (IMT) as a marker of subclinical atherosclerosis and whether such an association is independent of classical risk factors, insulin resistance, and metabolic syndrome features. RESEARCH DESIGN AND METHODS: We compared carotid IMT, as assessed by ultrasonography, in 85 consecutive patients with biopsy-proven NAFLD and 160 age-, sex-, and BMI-matched healthy control subjects. RESULTS: NAFLD patients had a markedly greater carotid IMT (1.14 +/- 0.20 vs. 0.82 +/- 0.12 mm; P < 0.001) than control subjects. The metabolic syndrome (according to Adult Treatment Panel III criteria) and its individual components were more frequent in those with NAFLD (P < 0.001). The marked differences in carotid IMT observed between the groups were only slightly weakened after adjustment for age, sex, BMI, smoking history, LDL cholesterol, insulin resistance (by homeostasis model assessment), and metabolic syndrome components. Notably, carotid IMT was strongly associated with degree of hepatic steatosis, necroinflammation, and fibrosis among NAFLD patients (P < 0.001 for all). Similarly, by logistic regression analysis, the severity of histological features of NAFLD independently predicted carotid IMT (P < 0.001) after adjustment for all potential confounders. CONCLUSIONS: These results suggest that the severity of liver histopathology among NAFLD patients is strongly associated with early carotid atherosclerosis, independent of classical risk factors, insulin resistance, and the presence of metabolic syndrome.     

Severe congenital absence of skin in a preterm infant

A severe case of aplasia cutis congenita in a preterm infant is described. Although major problems with thermoregulation and fluid balance were anticipated, these parameters were relatively easy to control once the patient was stabilized. Meticulous skin care and rapid formation of a membranous-like fibrous tissue layer covering the denuded areas probably played an important role in minimizing excessive fluid and heat loss. The prognosis in aplasia cutis congenita is determined by the underlying associated anomalies, the severity of skin lesions and, in our case, the maturity of the infant who died from complications of prematurity.     

Iron supplement in pregnancy and development of gestational diabetes—a randomised placebo-controlled trial

Objective  To test the hypothesis that iron supplement from early pregnancy would increase the risk of gestational diabetes mellitus (GDM).
Design  Randomised placebo-controlled trial.
Setting  A university teaching hospital in Hong Kong.
Population  One thousand one hundred sixty-four women with singleton pregnancy at less than 16 weeks of gestation with haemoglobin (Hb) level between 8 and 14 g/dl and no pre-existing diabetes or haemoglobinopathies.
Methods  Women were randomly allocated to receive 60 mg of iron supplement daily ( n = 565) or placebo ( n = 599). Oral glucose tolerance tests (OGTTs) were performed at 28 and 36 weeks. Women were followed up until delivery.
Outcome measures  The primary outcome was development of GDM at 28 weeks. The secondary outcomes were 2-hour post-OGTT glucose levels, development of GDM at 36 weeks and delivery and infant outcomes.
Results  There was no significant difference in the incidence of GDM in the iron supplement and placebo groups at 28 weeks (OR: 1.04, 95% confidence interval [CI]: 0.7–1.53 at 90% power) or 36 weeks. Maternal Hb and ferritin levels were higher in the iron supplement group at delivery ( P < 0.001 and P = 0.003, respectively). Elective caesarean section rate was lower in the iron supplement group (OR: 0.58, 95% CI: 0.37–0.89). Infant birthweight was heavier ( P = 0.001), and there were fewer small-for-gestational-age babies in the iron supplement group (OR: 0.46, 95% CI: 0.24–0.85).
Conclusion  Iron supplement from early pregnancy does not increase the risk of GDM. It may have benefits in terms of pregnancy outcomes.