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Biomedical subjects

K Takehara

Publications and source records attributed to K Takehara.

At least 163 records · Page 9Linked to original sources
PubMed1995

Elevated plasma endothelin levels in systemic sclerosis.

Endothelin is a novel potent vasoconstrictor peptide produced mainly by endothelial cells. Thrombomodulin is a high-affinity thrombin receptor on vascular endothelial cells that plays an important role as a natural anticoagulant. In this study, we measured plasma levels of endothelin and thrombomodulin in patients with systemic sclerosis or Raynaud's disease. Plasma levels of endothelin and the ratio of thrombomodulin to creatinine were significantly increased in patients with systemic sclerosis compared with normal controls, and there was a positive correlation between these two indicators (r = 0.615, P = 0.004). Moreover, plasma levels of endothelin were significantly higher in patients with diffuse systemic sclerosis than in patients with limited systemic sclerosis. In contrast, plasma levels of endothelin in patients with Raynaud's disease were not significantly increased. These results suggest that increased plasma levels of endothelin and thrombomodulin may reflect microvascular damage in systemic sclerosis.

Adult↗
PubMed1995

Autoantibodies to the heat-shock protein hsp73 in localized scleroderma.

We determined the presence of antibodies to the heat-shock protein hsp73 (anti-hsp73) in 57 serum samples from patients with localized scleroderma using an enzyme-linked immunosorbent assay (ELISA). In addition, 30 samples from healthy individuals, 30 from patients with systemic lupus erythematosus (SLE) and 32 from patients with systemic sclerosis were assessed. IgG and/or IgM anti-hsp73 antibodies were detected in 33% (19/57) of the patients with localized scleroderma. Among the three subtypes of localized scleroderma, generalized morphoea showed the highest incidence of anti-hsp73 antibodies (40%, 6/15). IgG and/or IgM anti-hsp73 antibodies were also detected in 9/30 samples (30%) from patients with SLE and in 13/32 samples (41%) from patients with systemic sclerosis, while the samples from the healthy controls were all negative for anti-hsp73. By immunoblotting, specific binding of antibodies to hsp73 was confirmed with representative serum samples that were positive for anti-hsp73 in the ELISA. Our findings indicate that the presence of anti-hsp73 is an additional immunological abnormality in localized scleroderma.

Adolescent↗
PubMed1995

Demonstration of interleukin-2, interleukin-4 and interleukin-6 in sera from patients with localized scleroderma.

Localized scleroderma has been reported to be accompanied by immunological abnormalities related to B cells, but little is known about T-cell activation in this disease. In this study, serum levels of interleukin-2 (IL-2), interleukin-4 (IL-4) and interleukin-6 (IL-6), which are known to be released by activated T cells, were determined using a sensitive enzyme-linked immunosorbent assay in 48 patients with localized scleroderma and 20 with systemic sclerosis, and in 20 healthy control subjects. IL-2, IL-4 and IL-6 were detected in serum from patients with localized scleroderma but not in that from healthy controls. The presence of antihistone antibodies correlated significantly with elevated IL-4 and IL-6 levels. Decreased serum levels of IL-2, IL-4 and IL-6 paralleled improvement in cutaneous sclerosis. Frequent detection of these lymphokines in serum from patients with localized scleroderma reflects T-cell activation in this disorder.

Autoantibodies↗
PubMed1995

Effect of biotin on ammonia intoxication in rats and mice.

The effects of biotin on ammonia concentration in blood and brain were evaluated in hyperammonemic rats and mice. Rats were injected with 5 mmol/kg BW of ammonium acetate, and mice were injected with 10 mmol/kg BW. Increases in blood ammonia levels in rats 15-30 min after ammonia loading were prevented by treatment with 0.2 ml/100 g BW of biotin or 0.04 ml/100 g BW of arginine-glutamate with statistical significance. Blood ammonia levels after ammonia loading were lower, although not significantly, in the arginine glutamate-treated rats than in the biotin-treated animals. In mice also, increases in blood and brain ammonia levels after ammonia loading were prevented by the administration of biotin. The decrease in brain glutamate and aspartate after ammonia loading was lower and the brain glutamine level was higher in biotin-treated mice than in the controls. These findings indicate the protective effect of biotin against ammonia intoxication.

Acetates↗
PubMed1995

Detection of antiribosomal P protein antibodies in patients with systemic sclerosis.

This study investigated the prevalence and clinical significance of anti-ribosomal P protein (anti-P) antibodies in patients with systemic sclerosis (SSc). Serum samples from 150 patients with SSc were examined by indirect immunofluorescence. ELISA and immunoblotting. Anti-P antibodies were detected in four (3%) patients with SSc. Three of the four patients showed SSc/SLE (systemic lupus erythematosus) overlap syndrome, but psychiatric disorders were not observed in these patients. By longitudinal immunoblotting analysis one patient, who was initially diagnosed with SSc, later developed anti-P antibodies along clinical manifestations of SLE. Our data suggest that anti-P antibodies are uncommon in SSc and that the presence of anti-P antibodies in patients with SSc indicates an overlap with SLE.

Adult↗
PubMed1995

Ultrasound measurement of skin thickness in systemic sclerosis.

Sclerotic skin change in systemic sclerosis (SSc) usually accompanies increased skin thickness. In order to quantify the cutaneous changes and to clarify the changes in the 'uninvolved' skin in systemic sclerosis (SSc), we measured the skin thickness on the chest, the forearms and the hands of 79 patients with SSc and 81 healthy controls with a B-mode ultrasound (30 MHz) apparatus. The thickness of the 'uninvolved', as well as the 'involved' skin in patients with SSc was significantly greater than that of healthy controls. Increased skin thickness on the forearms and/or the hands showed a 64.6% sensitivity and a 100% specificity for SSc. These results indicated that the skin which appears to be 'uninvolved' in patients with SSc is already pathologic, as shown by increased thickness. Moreover, measurement of skin thickness may be beneficial in the diagnosis of this disease at an early stage.

Adolescent↗
PubMed1995

Growth regulation in scleroderma fibroblasts: increased response to transforming growth factor-beta 1.

We investigated the responses of normal and scleroderma fibroblasts to various growth factors, especially transforming growth factor-beta 1 (TGF-beta 1). The effects of various growth factors on [3H]thymidine incorporation in normal and scleroderma fibroblasts were examined. [125I]-labeled platelet-derived growth factor (PDGF)-BB binding in scleroderma and normal fibroblasts was examined both in the presence and absence of TGF-beta 1 (1 ng/ml). Cytoplasmic protein was isolated and analyzed by Western blotting. Total RNA from fibroblasts was also isolated and analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR) using specific primer sets. Mitogenic responses to TGF-beta 1 (0.33-1 ng/ml) in seven scleroderma fibroblast strains were significantly greater than those in normal controls. [125I]-PDGF-BB binding to scleroderma fibroblasts was increased after TGF-beta 1 stimulation. The increased response to TGF-beta 1 was shown to be mediated through PDGF-like protein induction; TGF-beta 1-treated scleroderma fibroblasts produced greater amounts of 36-kD PDGF-like protein, which was reported previously as connective tissue growth factor (CTGF), than did TGF-beta 1-treated normal fibroblasts. TGF-beta 1 treatment also upregulated PDGF-alpha receptor expression in scleroderma fibroblasts but not in normal dermal fibroblasts. mRNA expression of CTGF and PDGF-alpha receptor was correlated with the above protein expression. These observations suggest that the increased growth response to TGF-beta 1 in scleroderma fibroblasts is mediated through the induction of CTGF and PDGF-alpha receptor.

Cell Division↗
PubMed1995

Significant correlation between connective tissue growth factor gene expression and skin sclerosis in tissue sections from patients with systemic sclerosis.

The role of some growth factors and cytokines in the pathogenesis of systemic sclerosis (SSc) has been suggested. In particular, the contribution of transforming growth factor beta in the progression of skin sclerosis is suspected. Connective tissue growth factor (CTGF) was originally identified in human umbilical vein endothelial cells, and a recent study has revealed that human skin fibroblasts produce CTGF after stimulation with transforming growth factor beta. In the present study, the distribution of CTGF gene expression in tissue sections from patients with SSc was investigated by digoxigenin-labeled in situ hybridization. Strong CTGF mRNA signals were observed in the fibroblasts in sclerotic lesions, especially in the deep dermis, of the skin specimens from patients with SSc, whereas there was no expression in the skin from normal controls. The number of fibroblasts with positive hybridization signals was more abundant in the dermis from the sclerotic stage than in that from the inflammatory stage. Our findings indicate a correlation between CTGF gene expression and skin sclerosis and support the hypothesis that transforming growth factor-beta plays an important role in the pathogenesis of SSc, because transforming growth factor beta is the only inducer for CTGF identified to date.

Adolescent↗
PubMed1995

Effects of various growth factors and histamine on cultured keloid fibroblasts.

OBJECTIVE AND METHODS: We investigated the effects of several growth factors on [3H]thymidine incorporation and procollagen type I carboxyterminal propeptide (P1CP) production, which reflects type I collagen metabolism, in keloid and normal fibroblasts. RESULTS: Six fibroblast cell strains, derived from keloid or normal skin, exhibited similar growth responses to platelet-derived growth factor, transforming growth factor beta 1 (TGF-beta 1), gamma-interferon (gamma-IFN) and histamine. In contrast, keloid fibroblasts showed significantly greater growth response to epidermal growth factor (EGF) than normal fibroblasts. P1CP production was 4.4 times higher in 6 strains of keloid fibroblasts than in 6 controls. Treatment with gamma-IFN (100 U/ml) decreased P1CP production in both groups; the effect was significantly greater in keloid fibroblasts. TGF-beta 1 treatment upregulated P1CP production in both groups. Treatment with histamine increased P1CP production in keloid fibroblasts, although it did not change that in the controls. CONCLUSION: EGF and histamine may play some role in the development of keloids.

Cell Division↗
PubMed1995

Elevated procollagen type I carboxyterminal propeptide production in cultured scleroderma fibroblasts.

BACKGROUND: We recently reported that the serum concentration of procollagen type I carboxyterminal propeptide (P1CP) in patients with systemic sclereosis (SSc) was elevated. In the present study, we investigated collagen metabolism in in vitro cultured scleroderma fibroblasts by measuring P1CP levels in the culture medium. METHODS AND RESULTS: Spontaneous P1CP production was 4.2 times higher in fibroblast cultures from patients with SSc (n = 11) than in those from healthy controls (n = 10). P1CP production in fibroblasts derived from diffuse cutaneous SSc patients was significantly greater than that from limited cutaneous SSc patients. The serum P1CP level in SSc patients was correlated with the P1CP production of cultured fibroblasts (r = 0.815, p < 0.005). Transforming growth factor beta increased P1CP production, and gamma-interferon decreased P1CP production similarly in both SSc and normal fibroblasts. In contrast, histamine dihydrochloride increased P1CP production only in SSc fibroblasts but not in controls. CONCLUSION: These findings suggest that P1CP production in SSc fibroblasts is relevant to in vivo collagen synthesis in SSc patients.

Adolescent↗
PubMed1995

Effectiveness of an inactivated goose parvovirus vaccine in Muscovy ducks.

With goose parvovirus (GPV) strain IH, an inactivated vaccine was prepared from allantoic fluid of embryonating Muscovy duck eggs inoculated with GPV. The response to vaccination was measured by virus neutralizing antibody titer against GPV. Offsprings from the vaccinated flock were introduced in a farm in which GPV infection had been experienced and examined for resistance to exposure to GPV. The results showed that the intramuscular vaccination to Muscovy ducks at any age stimulated significant virus neutralizing antibody levels, and that more than 90% Muscovy ducklings from the vaccinated parent flock survived after the exposure to GPV. Muscovy ducklings that passively possessed high level virus neutralizing antibodies also could respond to the vaccination and the induced antibodies remained for more than 2 months.

Aging↗
PubMed1995

An outbreak of goose parvovirus infection in Japan.

In a Muscovy duck breeding-growing farm in Aomori prefecture, most of ducklings hatched during spring in 1994 died within two-week-old. The mortality was nearly 100%. In most cases, birds died without clinical signs and some with leg weakness. By serological and virological tests, the outbreak was identified as a goose parvovirus infection. In pathological test, however, no typical manifestations of goose parvovirus infections (hepatitis and intranuclear inclusion bodies in hepatic cells) were detected.

Animals↗
PubMed1995

Type II citrullinemia associated with neutropenia.

A 37-year-old Japanese man was admitted with delirium and hyperammonemia. He was diagnosed as having type II citrullinemia because of an elevated citrulline level on amino acid analysis and very low hepatic argininosuccinate synthetase activity. He also showed a low neutrophil count and a low serum level of granulocyte colony-stimulating factor. Reduced production of this cytokine and/or impairment of its feedback regulation by the neutrophil count may have played a role in the neutropenia of this patient.

Adult↗
PubMed1995

The stimulatory effects of PDGF and TGF-beta 1 on dermal fibroblast attachment.

We investigated the effects of various growth factors (platelet-derived growth factor (PDGF), epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), transforming growth factor-alpha (TGF-alpha), transforming growth factor-beta 1 (TGF-beta 1), tumor necrosis factor-alpha (TNF-alpha), keratinocyte growth factor (KGF)) on fibroblast attachment to plastic plates. It is thought that cell attachment to plastic plates in vitro may represent the step between cell migration and proliferation in vivo during wound healing. Among the growth factors examined, only PDGF and TGF-beta 1 significantly increased fibroblast attachment to both uncoated and collagen-coated plates in a concentration-dependent manner. The addition of anti-PDGF antibody abolished the enhancing effect of PDGF but not that of TGF-beta 1, suggesting that the effect of TGF-beta 1 is not through the autocrine induction of PDGF-related activities secreted by the fibroblasts themselves. These data suggest that PDGF and TGF-beta 1 regulate fibroblast attachment to the suitable environment in the process of dermal wound healing in vivo.

Adult↗
PubMed1995

Serum aldolase level is a useful indicator of disease activity in eosinophilic fasciitis.

The serum levels of muscle enzymes have been considered normal in patients with eosinophilic fasciitis (EF). We observed elevated serum aldolase levels in 3 patients with EF. Serum creatinine kinase levels were within the normal range. We measured the aldolase levels longitudinally. In all patients, the levels decreased to the normal range after oral corticosteroid treatment, and skin sclerosis improved. Afterwards, serum aldolase levels increased again, with the recurrence of skin sclerosis. These observations suggest that serum aldolase level may be a useful indicator of disease activity.

Adult↗
PubMed1995

Nitric oxide and prostaglandins in regulation of acid secretory response in rat stomach following injury.

The gastric mucosa responds to taurocholate (TC) by significantly decreasing acid secretion. We examined the role of nitric oxide (NO) in this phenomenon in comparison with endogenous prostaglandins. A rat stomach was mounted in an ex-vivo chamber and perfused with saline, and the potential difference, luminal pH and acid responses were measured before and after the application of 20 mM TC for 30 min with or without pretreatment with the NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) or the cyclooxygenase inhibitor indomethacin. Exposure of the stomach to TC caused a reduction in potential difference, a decrease in acid secretion and an increase in luminal HCO3-. Pretreatment with L-NAME or indomethacin did not affect potential difference and HCO3- responses, but it significantly attenuated the decrease in acid secretion caused by TC. The effect of L-NAME was more potent than that of indomethacin, and, especially in the presence of L-NAME, acid secretion was actually enhanced after exposure to TC. Aminoguanidine, the selective inhibitor of inducible NO synthase, did not have any significant effect on either parameter. This effect of L-NAME was antagonized by the simultaneous administration of L-arginine but not by that of D-arginine, whereas the effect of indomethacin was reversed by PGE2. Acid secretion in normal stomachs was significantly reduced by nitroprusside and PGE2 but was not affected by either L-NAME or indomethacin.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗