Genetic variations of HSD11B2 in hypertensive patients and in the general population, six rare missense/frameshift mutations.

Mutations in the gene encoding 11beta-hydroxysteroid dehydrogenase type 2, HSD11B2, cause a rare monogenic juvenile hypertensive syndrome called apparent mineralocorticoid excess (AME). In AME, defective HSD11B2 enzyme activity results in overstimulation of the mineralocorticoid receptor (MR) by cortisol, causing sodium retention, hypokalemia, and salt-dependent hypertension. Here, we have studied whether genetic variations in HDS11B2 are implicated in essential hypertension in Japanese hypertensives and the general population. By sequencing the entire coding region and the promoter region of HDS11B2 in 953 Japanese hypertensives, we identified five missense mutations in 11 patients (L14F, n = 5; R74H, n = 1; R147H, n = 3; T156I, n = 1; R335H, n = 1) and one novel frameshift mutation (4884Gdel, n = 1) in a heterozygous state, in addition to 19 genetic variations. All genetic variations identified were rare, with minor allele frequencies less than 0.005. Four of 12 patients with the missense/frameshift mutations showed renal failure. Four missense mutations, L14F, R74H, R147H, and R335H, were successfully genotyped in the general population, with a sample size of 3,655 individuals (2,175 normotensives and 1,480 hypertensives). Mutations L14F, R74H, R147H, and R335H were identified in hypertensives (n = 6, 8, 3, and 0, respectively) and normotensives (n = 8, 12, 5, and 0, respectively) with a similar frequency, suggesting that these missense mutations may not strongly affect the etiology of essential hypertension. Since the allele frequency of all of the genetic variations identified in this study was rare, an association study was not conducted. Taken together, our results indicate that missense mutations in HSD11B2 do not substantially contribute to essential hypertension in Japanese.     

Serotype‐specific polysaccharide of Streptococcus mutans contributes to infectivity in endocarditis

Streptococcus mutans and other viridans streptococci have been implicated as major etiological agents of infective endocarditis. The serotype‐specific rhamnose‐glucose polysaccharide (RGP) of S. mutans has several biological functions that appear to be essential for the induction of infective endocarditis. The aim of this study was to examine the contribution of RGP to the infectivity of S. mutans in infective endocarditis using a rat model. The RGP‐defective mutant of S. mutans showed reduced ability to induce infective endocarditis compared to the parental strain. The ability of S. mutans to induce infective endocarditis was not consistent with the binding capacity of the organism to extracellular matrix proteins. The results suggest that S. mutans containing whole RGP is more virulent than the RGP‐defective mutant, and the RGP has an important role for the induction of infective endocarditis by S. mutans.     

A new HPLC fluorimetric method to monitor urinary delta-aminolevulinic acid (ALA-U) levels in workers exposed to lead

Summary A new sensitive HPLC method for the determination of urinary delta-aminolevulinic acid (ALA-U) was used to evaluate the relationship between blood-lead (Pb-B) and ALA-U levels in male workers exposed to lead. The differences between the ALA-U levels determined by this method (ALAU-HP) and by a colorimetric method (ALA-U-CL) are discussed. The HPLC method gave values similar to the ALA-U-CL values at high ALA-U level. However, at low blood-lead levels (58 ± 22 g/l, n = 23), the mean ALA-U-HP level corrected by urinary creatinine level was one-third of the corrected ALA-UCL level (0.83 ± 0.14 and 2.4 ± 0.5 mg/g creatinine, respectively). A significant increase of the mean corrected ALA-U-HP level was observed at 162 ± 22 g/l Pb-B (P < 0.05, n = 26), while that of ALA-UCL was observed at 245 ± 30 g/l Pb-B (P < 0.01, n = 37). The regression equation based on the logistic model fitted well to the relationship data between the Pb-B level and the percentage of the subjects with corrected ALA-U-HP above the cut-off point (1.12 mg/g creatinine) and the expected Pb-B level for 50% response was 270 g/l Pb-B, while it did not fit well to the relationship data between Pb-B level and the percentage of the subjects with corrected ALAU-CL above the cut-off point (3.5 mg/g creatinine). The maximum responses for the two sets of corrected ALA-U levels were both observed at 625 ± 25 g/l. The corrected ALA-U level by HPLC method seems to be a useful indicator for biological monitoring of exposure to lead at low levels (< 400 g/l Pb-B = health-based biological limit, WHO) as well as high ones.     

Clinical significance of antibodies to nonstructural and core proteins of hepatitis C virus in posttransfusion hepatitis patients during long-term follow-up

The prevalence of hepatitis C antibodies (anti- HCV) among multitransfused patients was studied and compared with predicted values obtained from a post-transfusion hepatitis study and from data on the prevalence of anti-HCV among blood donors. The prevalence of hepatitis B core antibodies (anti-HBc) was also studied to determine the routes of transmission of hepatitis C virus. The patients consisted of 65 dialysis patients (57 on haemodialysis and 8 on continuous ambulatory peritoneal dialysis) and 71 leukemia patients in long-term remission [49 with acute myeloid leukemia (AML) and 22 with acute lymphatic leukemia (ALL)]. The presence of anti-HCV was investigated using a second generation enzyme-linked immunosorbent assay. Reactive samples were confirmed by a second generation recombinant immunoblot assay. Anti-HBc was studied in the 65 dialysis patients and in 40 of the leukemia patients. Three (4.6%) of the 65 dialysis patients and 12 (24.5%) of the 49 AML patients were anti-HCV positive whereas all of the ALL patients were seronegative. The total number of blood units transfused to 134 patients (data on two dialysis patients were not available) was 18,148, out of which 17,575 units had been transfused prior to the initiation of anti- HCV screening of blood donors. On the basis of the anti-HCV prevalence among blood donors and the incidence of post-transfusion hepatitis, the predicted number of seropositive patients was 11 and 18, respectively. Five of the 65 dialysis patients were anti-HBc positive, compared with only one of the 40 leukemia patients. It is concluded that the anti-HCV prevalence among dialysis and leukemia patients is concordant with the risk of receiving contaminated blood products, whereas hepatitis B infection may have other routes of transmission in dialysis patients. © 1993 Wiley-Liss, Inc.     

Activated T-Lymphocytes Express Occludin, a Component of Tight Junctions

T-lymphocytes routinely traffic from the lymphoid and vascular compartments to the tissues during immune surveillance and inflammatory responses. This egress occurs without compromising endothelial barrier, which is maintained by tight junctions (zonula occludens). We report that T-lymphocytes up-regulate the expression of occludin, a major component of the tight junction in response to stimulation with phorbol ester (PMA) + calcium ionophore, CD3 antibody or T-cell receptor (TCR) antibody. Only activated T-lymphocytes express occludin; this adhesion molecule is nearly absent in resting T-lymphocytes. By immunofluorescence, occludin is seen in lymphocyte aggregates, but does not appear to mediate aggregation since only 50% of the cells in these clusters express occludin. Occludin is expressed between 8 and 24 h following stimulation, and persists for at least 48 h. These data indicate that activated T cells produce occludin which may regulate lymphocyte adhesion and trafficking.     

Rat mast cell granules reacting with a mouse monoclonal antibody M6764 which recognizes the same epitope of a mouse monoclonal antibody HNK-1.

Rat mast cell granules and plasma membrane fractions were obtained by homogenization of highly purified rat mast cells and isolation in a Percoll gradient and a sucrose gradient, respectively. Immunostaining of rat mast cells, granules and plasma membrane fractions was performed with mouse monoclonal antibody M6764 which was produced against the crude membrane fractions of the neural tubes. Rat mast cells and granules were immunostained with the monoclonal antibody, but not the plasma membrane fractions. The granules fixed with glutaraldehyde-paraformaldehyde showed ring-like forms. Chloroform-methanol treatment did not effect the staining of rat mast cells and granules with the monoclonal antibody. Western blotting analysis of rat mast cells and granules with the monoclonal antibody showed broad protein bands ranging from 100 to 250 kD.     

Effect of phorbol myristate acetate (PMA) on diphosphoinositide (DPI) synthesis in rat mast cell granules

Rat mast cell granules were obtained by homogenization of highly purified rat mast cells and isolated in a Percoll gradient. DPI synthesis in rat mast cell granules was assayed by measuring the incorporation of 32P from [gamma 32P] ATP into DPI in the absence of exogenous phosphatidylinositol (PI). Lipids were isolated with methanol/chloroform/HC1 and were separated by thin-layer chromatography on oxalic acid impregnated silica gel plates. DPI areas were identified by staining with iodine, scraped and measured for 32P radioactivity. The addition of PMA to the granules caused an increase of DPI synthesis, which can be catalysed by PI kinase. Neither an inactive phorbol ester, 4-alpha-phorbol-12, 13-didecanoate, nor dimethyl sulfoxide (DMSO) used as a solvent for PMA had any effect. The effect of PMA in the DPI synthesis was dose-dependent and maximal effects were observed at 10-100 ng/ml. Dose-response curves of the effects of PMA in DPI synthesis in the granules corresponded to those of other biochemical effects of PMA in rat mast cells, such as mediator release mediated through the activation of protein kinase C. These results suggest that PMA may directly affect PI kinase or indirectly regulate its activity in rat mast cell granules.     

Characterization of enteropathogenic and enteroaggregative Escherichia coli isolated from diarrheal outbreaks.

Virulence characteristics of diarrheal outbreak-associated Escherichia coli O55:NM, O126:NM, and O111:NM were examined. The E. coli O55:NM strains were atypical enteropathogenic E. coli (EPEC), while the E. coli O126:NM and O111:NM strains should be classified as enteroaggregative E. coli (EAggEC). The contributions of EPEC and EAggEC to the human disease burden in Japan might be significantly greater than is currently appreciated.     

Association between Vitamin D and Heart Failure Mortality in 10,974 Hospitalized Individuals

A broad range of chronic conditions, including heart failure (HF), have been associated with vitamin D deficiency. Existing clinical trials involving vitamin D supplementation in chronic HF patients have been inconclusive. We sought to evaluate the outcomes of patients with vitamin D supplementation, compared with a matched cohort using real-world big data of HF hospitalization. This study was based on the Diagnosis Procedure Combination database in the Japanese Registry of All Cardiac and Vascular Datasets (JROAD-DPC). After exclusion criteria, we identified 93,692 patients who were first hospitalized with HF between April 2012 and March 2017 (mean age was 79 ± 12 years, and 52.2% were male). Propensity score (PS) was estimated with logistic regression model, with vitamin D supplementation as the dependent variable and clinically relevant covariates. On PS-matched analysis with 10,974 patients, patients with vitamin D supplementation had lower total in-hospital mortality (6.5 vs. 9.4%, odds ratio: 0.67, p < 0.001) and in-hospital mortality within 7 days and 30 days (0.9 vs. 2.5%, OR, 0.34, and 3.8 vs. 6.5%, OR: 0.56, both p < 0.001). In the sub-group analysis, mortalities in patients with age < 75, diabetes, dyslipidemia, atrial arrhythmia, cancer, renin-angiotensin system blocker, and β-blocker were not affected by vitamin D supplementation. Patients with vitamin D supplementation had a lower in-hospital mortality for HF than patients without vitamin D supplementation in the propensity matched cohort. The identification of specific clinical characteristics in patients benefitting from vitamin D may be useful for determining targets of future randomized control trials.