Human vascular smooth muscle cells and endothelial cells lack catalase activity and are susceptible to hydrogen peroxide

⁵Cr release as lytic and cell detachment as nonlytic injury were employed to estimate neutrophil-mediated injury of cultured human vascular smooth muscle cells and endothelial cells. The reagents hydrogen peroxide or hypoxanthine-xanthine oxidase produced dose-dependent killing and nonlytic cell detachment, which were specifically inhibited by catalase but not by superoxide dismutase. The concentration of hydrogen peroxide or xanthine oxidase to induce cell detachment was less than lytic dose, suggesting that cell detachment was a much more sensitive assay of injury. Neutrophil-mediated cell lysis averaged 15% at most and was mostly dependent on hydrogen peroxide, while neutrophil-mediated cell detachment was nearly 100% and its dependency on hydrogen peroxide varied from 46% to 60%. These results suggest that vascular smooth muscle cells and endothelial cells in neutrophil-mediated events are destroyed by a hydrogen peroxide-dependent process, mainly via a nonlytic cell detachment mechanism. There was no striking difference of sensitivity to hydrogen peroxide between vascular smooth muscle cells and endothelial cells. Vascular smooth muscle ceils and endothelial cells contained fairly high concentrations of superoxide dismutase, but not catalase, activity. The sensitivity of these cells to hydrogen peroxide but not to superoxide may arise from the fact that these cells lack intracellular catalase activity. The injury of vascular cells, which constitute important components of blood vessels, may lead to vascular injury and subsequent tissue damage.     

Open food challenge with milk, egg white and wheat

Background: A method for open food challenge test to determine food allergy has not been established in an evidence-based manner. Methods: We conducted an analysis of 438 open food challenges of raw milk (n=133, mean age 2.7+/-1.9 years), boiled egg white (n=216, 2.8+/-2.1 years) or udon noodles (n=89, 2.7+/-1.7 years) for the patients aged 1 year or more. Doses were increased (trace amounts, 1 g, 2 g, 5 g, 10 g, 20-30 g) every 20 minutes. Results: In total, 151 (38.5%) of food challenges were positive. The positive rates of milk, egg and wheat challenges were 35.8%, 42.4% and 33.3%, respectively. Of these, 76.2%, 32.5%, 27.8% and 0.7% had, respectively, skin, respiratory, gastrointestinal and cardiovascular symptoms. Although the prevalence of positive challenge increased with level of specific IgE, it did not correlate with the threshold amount of positive food challenge or the severity of symptoms. Among the challnege positive patients, 10.6% required injection of antihistamines, corticosteroids or adrenalines for the treatment of the symptoms. Conclusions: This challenge protocol seemed to be appropriate and safe.     

Evaluation of the drug lymphocyte stimulation test (DLST) with shosaikoto]

BACKGROUND: Our aim is to evaluate the significance of DLST by Shosaikoto. METHODS: We clinically evaluated 3 cases of drug-induced pneumonia assumed to be caused by Shosaikoto, and we performed DLST of Shosaikoto for healthy controls, and compared the data with drug-induced pneumonia cases of Shosaikoto. RESULTS: As clinical characteristics of 3 cases, 2 cases were positive for hepatitis C virus antibody, and 1 case was positive for DLST of Shosaikoto. The observed chest high-resolution CT (HRCT) findings showed hypersensitivity pneumonia (HP) pattern in all 3 cases. Prognosis was good in all 3 cases. DLST of Shosaikoto was positive in 27.5% of healthy controls. Stimulation index (S.I.) of DLST in drug-induced pneumonia cases increased depending on drug dilution density, compared to that of healthy controls. CONCLUSION: DLST of Shosaikoto showed high false-positive rate. However, we may be able to distinguish the true-positive cases with the false-positive cases by comparing the S.I. of DLST according to drug dilution density.     

No association of GSK3beta gene (GSK3B) with Japanese schizophrenia.

Several lines of evidence indicate that glycogen synthase kinase-3beta (GSK3beta) is one of the candidates for schizophrenia-susceptibility factor. However, it has not been reported the association analysis between GSK3beta gene (GSK3B) and Japanese schizophrenia based on linkage disequilibrium (LD). We provide an association analysis using relatively large samples (381 schizophrenia, and 352 controls) after determination of "tag single nucleotide polymorphisms (SNPs)." In this LD mapping, we selected and genotyped for eight polymorphisms (seven SNPs and one diallelic (CAA)(n) repeat), which covered the entire region of GSK3B, and determined two "tag SNPs." In the following association analysis using these two "tag SNPs," we could not find association with Japanese schizophrenia. Furthermore, we also include subgroup analysis considering age-at-onset and subtypes, neither could we find associations. Because our samples provided quite high power, these results indicate that GSK3B may not play a major role in Japanese schizophrenia.     

Astaxanthin limits exercise-induced skeletal and cardiac muscle damage in mice

Dietary antioxidants may attenuate oxidative damage from strenuous exercise in various tissues. Beneficial effects of the antioxidant astaxanthin have been demonstrated in vitro, but not yet in vivo. We investigated the effect of dietary supplementation with astaxanthin on oxidative damage induced by strenuous exercise in mouse gastrocnemius and heart. C57BL/6 mice (7 weeks old) were divided into groups: rested control, intense exercise, and exercise with astaxanthin supplementation. After 3 weeks of exercise acclimation, both exercise groups ran on a treadmill at 28 m/min until exhaustion. Exercise-increased 4-hydroxy-2-nonenal-modified protein and 8-hydroxy-2'-deoxyguanosine in gastrocnemius and heart were blunted in the astaxanthin group. Increases in plasma creatine kinase activity, and in myeloperoxidase activity in gastrocnemius and heart, also were lessened by astaxanthin. Astaxanthin showed accumulation in gastrocnemius and heart from the 3 week supplementation. Astaxanthin can attenuate exercise-induced damage in mouse skeletal muscle and heart, including an associated neutrophil infiltration that induces further damage.     

Mevalonic acidemia: First case of Japan

Summary Mevalonic acidemia is a rare metabolic disorder due to mevalonate kinase deficiency which affects the biosynthesis of cholesterol and nonsterol isoprenes. We report the first case of Japan. The clinical course is characterized by intrauterine growth retardation, postnatal growth failure, intractable diarrhea, liver dysfunctions and death at three months of age. Dysmorphic features including triangular face, protrusion of forehead, hypertelorism, low set ears and micrognathism were noted. High mevalonic acid level was found by GC/MS.     

Diverse functions of the p75 neurotrophin receptor

The pan-neurotrophin receptor p75NTR belongs to a large family of receptors, which includes tumor necrosis factor receptors, Fas and approximately 25 other members. The p75NTR is the first receptor to be cloned molecularly. Recent years have seen the emergence of a consensus regarding the signaling pathways activated by p75NTR and its potential biological function, although receptor characterization had not been targeted for some years. We now know that p75NTR has surprisingly diverse effects, ranging from cell death to regulation of axon elongation. This diversity can be explained by the complex formation of p75NTR with other receptors and multiple signaling molecules that interact with the intracellular domain of p75NTR.     

Detection of the putative E2 protein of hepatitis C virus in human liver

The question was asked whether a predicted envelope protein, considered to be processed from the polyprotein precursor encoded by the putative E2/NS1 region of the hepatitis C virus (HCV) genome, may be observed in HCV-infected humans. Two polyclonal antibodies against recombinant E2/NS1 proteins were prepared and their reactivity tested against liver extracts from HCV-infected patients by immunoblotting analysis. A band corresponding to a size of 44 kDa was detected in liver extracts from patients who were positive for the HCV-specific antibody anti-C100-3 but not in liver extracts from patients who did not have anti-C100-3 antibody. Additionally, no band was detected using preimmune sera or antisera which had been preabsorbed with recombinant E2/NS1 proteins. Deglycosylation studies demonstrated that the 44 kDa protein was a glycosylated form of a 38 kDa protein which corresponds to the predicted molecular weight of the putative E2/NS1 protein. These results suggest that the 44 kDa protein is a product of the E2/NS1 region. Frequent observation of the 44 kDa band in cases of chronic active hepatitis C suggests a correlation between the expression of this protein and the progression of hepatitis. © 1994 Wiley-Liss, Inc.     

Epidemiologic survey and genetic analysis of endemic hepatitis C virus infection in a Japanese town with a high prevalence of hepatitis B virus carriers

Mass screening for hepatitis C virus antibody was carried out in 875 inhabitants (313 men and 562 women) of a town in Japan with a high rate of hepatitis B virus infection. The overall rate of positivity for anti-HCV was 8.8% (6.4% in men and 10,1% in women). The rate of positivity for hepatitis B virus surface antigen was 11.2%. Five subjects (0.6%) were positive for both markers. HCV-RNA was detected in 65 (88.4%) of 77 individuals who were positive for anti-HCV and in 1 (1.5%) of 60 individuals negative for anti-HCV. The genotype of the HCV genome was determined by PCR analysis using type-specific primers in 60 individuals. HCV type 1b was detected in 51 subjects (85%), type 2a in 3 subjects (5%), and type 2b in 6 subjects (10%). None of the individuals was infected with more than one genotype. The nucleotide sequences of the partial nonstructural 5 region of HCV type 1b genotype obtained from 6 individuals showed at least 92.0% homology in the nucleotide sequence, and 94.8% homology in the amino acid sequence. Homology among these clones was greater than their homology with previously described type 1 b sequences. The findings suggest that there was a specific local origin of HCV infection, although it was not possible to identify any single source of HCV infection. The results also indicate the presence of asymptomatic HCV carriers. © 1995 Wiley-Liss, Inc.