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Biomedical subjects

K Uchida

Publications and source records attributed to K Uchida.

At least 433 records · Page 24Linked to original sources
PubMed1998

Inhibitory effects of the herbal medicine Sho-saiko-to (TJ-9) on cell proliferation and procollagen gene expressions in cultured rat hepatic stellate cells.

BACKGROUND/AIMS: It is of extreme importance to prevent liver fibrosis and subsequent progression to liver cirrhosis. The aim of our study was to elucidate in vitro whether Sho-saiko-to exerted inhibitory effects on hepatic stellate cells. METHODS: Hepatic stellate cells were isolated from male Wistar rats. Water-soluble ingredients of Sho-saiko-to were obtained at concentrations of 10, 100, 250, 500 and 1000 microg/ml. Morphological transformation was observed under a phase-contrast microscope. Flow cytometric analysis was performed on day 4 after culture to evaluate the potential to proliferate of the stellate cells by analyzing cell cycles. Northern blot analysis was carried out on day 3 after culture to determine the expressions of type I and type III procollagen mRNAs. RESULTS: (i) Sho-saiko-to 500 and 1000 microg/ml inhibited morphological transformation of the stellate cells to myofibroblast-like cells. (ii) Sho-saiko-to 500 and 1000 microg/ml significantly (p<0.0001) accumulated the cells in the G0/G1 phase (118.8+/-0.7%, 119.2+/-0.5%, respectively as compared with control) and significantly (p<0.0001) decreased cell numbers subsequently in G2/M phase (47.5+/-8.1%, 48.9+/-2.0%, respectively). (iii) Sho-saiko-to 500 and 1000 microg/ml also significantly (p<0.05 or p<0.0001) suppressed procollagen mRNA expression of type I to 51.5+/-6.4%, 34.9+/-3.7%, respectively, and type III to 51.3+/-12.3%, 46.7+/-11.4%, respectively. CONCLUSIONS: We have clarified the inhibitory effects of Sho-saiko-to on hepatic stellate cells in vitro. Sho-saiko-to could be a potent inhibitor in the pathogenesis of liver fibrosis.

Adipocytes↗
PubMed1998

Interferon gamma treatment prevents procollagen gene expression without affecting transforming growth factor-beta1 expression in pig serum-induced rat liver fibrosis in vivo.

BACKGROUND/AIM: The aim of this study was to investigate the effect of interferon gamma on the synthesis of matrix proteins such as collagens with the relation to transforming growth factor-beta1 expression in vivo. METHODS: We investigated the effects of interferon gamma in a model of liver fibrosis induced by pig serum in male Wistar rats, which develops fibrosis without an increase in serum alanine aminotransferase (i.e., without hepatocyte injury). Rats were injected with 0.5 ml of pig serum twice a week for 8 weeks with or without 20,000 or 50,000 U of interferon gamma. RESULTS: Interferon gamma at doses up to 50,000 U/day prevented fibrosis, as indicated by reduced hydroxyproline content in the liver. Interferon gamma at 50,000 U/day also reduced expression of type I and III procollagen in the liver. However, the expression of transforming growth factor-beta1 mRNA and protein in the liver was not reduced by interferon gamma. Histologically, interferon gamma at 50,000 U/day also reduced the number of myofibroblast-like cells (activated stellate cells). CONCLUSIONS: These results indicate that interferon gamma can prevent fibrosis by inhibiting the activation and proliferation of stellate cells, resulting in reduced expression of procollagen without affecting transforming growth factor-beta1 expression in pig serum-induced rat liver fibrosis in vivo.

Animals↗
PubMed1998

Coat assembly directs v-SNARE concentration into synthetic COPII vesicles.

COPII proteins are required to create transport vesicles and to select cargo molecules for transit from the ER. A reconstituted liposome budding reaction was used to detect the capture and concentration of membrane-associated v-SNARE molecules into synthetic COPII vesicles. A novel glutathione-phosphatidyl-ethanolamine conjugate (Glut-PE) was synthesized and incorporated into chemically defined liposomes to provide binding sites for GST hybrid proteins. Large liposomes containing bound cytoplasmic domains of the v-SNAREs, Sec22p or Bos1p, or of the ER resident proteins, Sec12p and Ufe1p, were exposed to COPII proteins and GMP-PNP. v-SNAREs but not resident proteins were concentrated in synthetic COPII vesicles generated from donor liposomes. We conclude that COPII proteins are necessary and sufficient for cargo selection and vesicle morphogenesis.

Biological Transport↗
PubMed1998

Pharmacological characterization of endothelin-induced contraction in the guinea-pig oesophageal muscularis mucosae.

1. In the oesophageal muscularis mucosae, we examined the effects of endothelin-1 (ET-1), endothelin-2 (ET-2), endothelin-3 (ET-3) and sarafotoxin S6c (SX6c) as agonists, and FR139317, BQ-123 and RES-701-1 as endothelin receptor antagonists. 2. All of the endothelins produced tonic contractions which were frequently superimposed on rhythmic motility in a concentration-dependent manner. The order of potency (-log EC50) was ET-1 (8.61)=SX6c (8.65)>ET-2 (8.40)>ET-3 (8.18). 3. FR139317 (1-3 microM) and BQ-123 (1 microM) caused parallel rightward shifts of the concentration-response curve to ET-1, but at higher concentrations caused no further shift. RES-701-1 (3 microM) caused a rightward shift of the concentration-response curve to ET-1, while RES-701-1 (10 microM) had no additional effect. RES-701-1 (0.1-1 microM) concentration-dependently caused a rightward shift of the concentration-response curve to SX6c. The contraction to ET-1 (10 nM) in preparations desensitized to the actions of SX6c was greatly inhibited by pretreatment with FR139317 (10 microM). 4. Modulation of the Ca2+ concentration in the Krebs solution caused the concentration-response curve to ET-1 or SX6c to shift to the right and downward as external Ca2+ concentrations decreased. Verapamil (30 microM) abolished rhythmic motility induced by ET-1 or SX6c. Ni2+ (0.1 mM) weakly inhibited ET-1- or SX6c-induced tonic contraction. SK&F 96365 (60 microM) completely inhibited ET-1-induced contractions. 5. We conclude that there are two types of ET-receptors, excitatory ET(A)- and ET(B)-receptors in the oesophageal muscularis mucosae. These receptors mediate tonic contractions predominantly by opening receptor-operated Ca2+ channels (ROCs) and partly by opening T-type Ca2+ channels, and mediate rhythmic motility by opening L-type Ca2+ channels.

Animals↗
PubMed1998

Cervical myeloradiculopathy with entrapment neuropathy: a study based on the double-crush concept.

In an attempt to formulate a standardised approach to the diagnosis and management of patients with the double-crush syndrome, we reviewed 65 surgical cases (39 men and 26 women) with cervical myeloradiculopathy associated with entrapment neuropathy in the arm by examining the clinical features, results of nerve conduction velocity studies and distribution of the vertebral levels of compression. Fifty-three patients (average age, 43 years) presented with a carpal tunnel syndrome at the wrist and cervical lesions (41 with spondylosis and 12 with ossified posterior longitudinal ligament), while 12 had a cubital tunnel syndrome at the elbow with cervical lesions (eight with spondylosis and four with ossification of the posterior longitudinal ligament). In the former group, the lesions were found mostly at C5-6 and C6-7 levels, while in the latter group involvement of C6-7 was frequently observed. Two patients in each group required additional cervical decompression after carpal or cubital tunnel release. A retrospective review of our patients suggested that it is reasonable to pursue an accurate diagnosis followed by treatment based on individual neurological and electrophysiological findings, but taking into consideration the significant level of physical impairment associated with cord compromise, we believe that it may be reasonable to perform a cervical decompression rather than peripheral nerve release in such cases. Our findings suggest that one should be aware of a double-crush during examination of patients complaining of neck and hand problems.

Adult↗
PubMed1998

Inhaled corticosteroid reduced lamina reticularis of the basement membrane by modulation of insulin-like growth factor (IGF)-I expression in bronchial asthma.

BACKGROUND: Pathological studies of bronchial biopsy specimens have confirmed the apparent thickening of lamina reticularis of the epithelial basement membrane. Corticosteroids have proven to be most effective in modifying airway inflammation. However, there is not much data on the effects of corticosteroid-treatment on the basement membrane. OBJECTIVE: To investigate the effects of inhaled beclomethasone dipropionate (BDP) on the thickness of basement membrane and cellular infiltration into the bronchial mucosa, and the expression of growth factors in patients with asthma. METHODS: We studied bronchial biopsies from 24 asthmatic patients before and after treatment with inhaled BDP, 400 microg twice a day or placebo, for 6 months in a double-blind manner. Each subject recorded daily asthma symptoms and peak expiratory flow (PEF). Lung function and bronchial responsiveness to methacholine were measured before and after treatment. The thickness of the basement membrane was determined by electron microscopy. Inflammatory cells and the expression of growth factors were examined by immunohistochemistry in endobronchial biopsy specimens. RESULTS: After 6 months of treatment, we observed a significant improvement of asthma symptoms (P<0.01), PEF (P<0.01), diurnal variation of PEF (P<0.05), and airway responsiveness (P< 0.05) in the BDP group compared with the placebo group. This was accompanied by a significant decrease in the thickness of the lamina reticularis (P < 0.001), and in the number of activated eosinophils (P<0.01), T-lymphocytes (P<0.01), and fibroblasts (P < 0.05) in BDP-treated patients. There was also a reduction in the expression of insulin-like growth factor (IGF)-I (P < 0.01). Significant correlation was found between the IGF-I expression and collagen thickening (rs = 0.34, P<0.01), and the number of fibroblasts (rs = 0.45, P < 0.01). CONCLUSION: These results suggest that corticosteroid treatment in asthma can reduce the lamina reticular thickness by modulation of IGF-I expression with consequent inhibition of the airway infiltration by inflammatory cells, and therefore may help to prevent remodelling of the airways.

Administration, Inhalation↗
PubMed1998

Altered antigenicity of M-177, a 177-kDa allergen from the house dust mite Dermatophagoides farinae, in stored extract.

BACKGROUND: A high molecular weight allergen, M-177 (177 kDa) was isolated from Dermatophagoides farinae using a specific antibody raised to an allergenic clone Mag 3, which was obtained by immunoscreening a mite cDNA library. The potent IgE reactivity of M-177 is comparable with that of Der f 2. OBJECTIVE: The aim of this study was to analyse the molecular characteristics and the allergenic activity of M-177 in stored mite extracts. METHODS: Antigens were analysed by immunoblotting and enzyme-linked immunosorbent assay (ELISA; inhibition). Allergenic activity was estimated from IgE reactivity and the results of a histamine release assay. RESULTS: The intact M-177 molecule was present in high concentrations in fresh extract obtained from purified mite bodies, but was only detected in small amounts in stored extracts. Instead of the intact molecule, anti-Mag 3 antibody detected various cross-reactive antigens in the stored preparations. Studies of a stored liquid extract showed that these cross-reactive antigens were produced by the degradation of M-177, and that this change was suppressed by the addition of protease inhibitors. Interestingly, the allergenic activity of the fragmented M-177 (sM-177) isolated from the stored extracts was greater than that of the intact antigen. Specific IgE reacted with sM-177 in 84.2% of 38 sera samples from patients allergic to mites, while 65.8% were positive for M-177-specific IgE. Similarly, the histamine release test showed that sM-177 had greater allergenic activity in vitro. ELISA inhibition indicated that the increased allergenic activity resulted from alteration of the antigenicity with the degradation of M-177. CONCLUSIONS: M-177 is a protease-sensitive allergen. The breakdown products of M-177 provoked higher allergenic activity than the intact allergen.

Animals↗
PubMed1998

Control of expression of a gene encoding an extensin by phytochrome and a blue light receptor in spores of Adiantum capillus-veneris L.

In the present study, using a newly developed fluorescent differential display technique, we have carried out large-scale screening for genes whose expression was regulated by phytochrome and antagonistically by a blue light receptor in the spores of the fern Adiantum capillus-veneris L. Spores after imbibition were briefly irradiated with red, red/blue or blue light and collected 8 h after the irradiation. Total RNA was isolated from each sample and used to make cDNA with an oligo-dT primer. The cDNA was then used as a template for PCR with the oligo-dT primer and 80 arbitrary primers. The resulting PCR products were analyzed by an automated fluorescent DNA sequencer. Among 8000 displayed bands, we identified 15 up-regulated and four down-regulated bands by red light, and this red light effect was irreversibly reversed by blue light. We cloned one of the up-regulated cDNA fragments and used it to screen a cDNA library prepared from the spores. The isolated insert is predicted to encode Ser-(Pro)n repeats and showed homology with cell wall-associated extensins. The expression of this cDNA was induced 8 h after a red light treatment and the red light induction was photoreversibly prevented by far-red light and photoirreversibly by blue light. The mRNA of this gene was detectable 4 h after red light irradiation and gradually increased in germinating spores.

Amino Acid Sequence↗
PubMed1998

A simple and early prognostic index for acute renal failure patients requiring renal replacement therapy.

Recent advances in technology have not substantially changed the high mortality rate associated with acute renal failure (ARF). To obtain a simple, valid prognostic index, we retrospectively evaluated the relative importance of demographic data, causes (acute insults) of renal failure, and comorbid clinical conditions for the outcome in 102 ARF patients who received renal replacement therapy with an overall mortality rate of 65% (66 of 102). There were no significant differences between survivors and nonsurvivors in age and gender. Mortality according to acute insults was similar to that of the whole population studied. Of the 10 clinical conditions at the time of the first renal replacement therapy, mechanical ventilation (p = 0.0002), cardiac failure (p = 0.0006), hepatic failure (p = 0.003), central nervous system dysfunction (p = 0.005), and oliguria (p = 0.04) were found to be significantly related to mortality by univariate analysis. Furthermore, multivariate analysis demonstrated that only mechanical ventilation, cardiac failure, and hepatic failure were significant risk factors. Survival was directly related to the number of significant variables in univariate analysis: zero, 89% (8 of 9); one, 62% (21 of 34); two, 19% (5 of 27); three, 10% (2 of 20); four, 0% (0 of 8); five, 0% (0 of 4). This simple and early prognostic index, derived from the assessment of clinical conditions which were easily determined at the patient's bedside, could be useful for outcome prediction in ARF patients requiring renal replacement therapy.

Acute Kidney Injury↗
PubMed1998

Changes in tissue oxygen tension caused by contrast media injected into the femoral artery of the dog.

PURPOSE: To document changes in tissue oxygen tension as measured directly in an area perfused with contrast medium. MATERIAL AND METHODS: Changes in tissue oxygen tension in response to the injection of ionic and non-ionic contrast media into the femoral arteries were measured in the femoral adductor (proximal) and gastrocnemius (distal) muscles of 8 dogs. Amidotrizoic-acid and iopamidol were injected in two different iodine concentrations (370 mg I/ml and 185 mg I/ml respectively) and tissue oxygen tension in the proximal and distal muscles was monitored continuously using polarographic needle electrodes. RESULTS AND CONCLUSION: A transient decrease and subsequent increase of muscle tissue oxygen tension were observed after the injection. The extent of these changes depended on the concentration and osmolality of the medium. To minimize changes in peripheral tissue oxygen tension, contrast media with low osmolality and low concentration are recommended for femoral angiography.

Angiography↗
PubMed1998

Over-expression of glutathione S-transferase Yp isozyme and concomitant down-regulation of Ya isozyme in renal cell carcinoma of rats induced by ferric nitrilotriacetate.

An iron chelate, ferric nitrilotriacetate (Fe-NTA), induces renal proximal tubular damage, a consequence of iron-catalysed Fenton-like reactions, that finally leads to a high incidence of renal cell carcinoma (RCC) in rodents. Glutathione S-transferase (GST) is a family of enzymes that play an important role in detoxification of hydrophobic and electrophilic molecules, and has been associated with putative preneoplastic foci of rat hepatocarcinogenesis and chemotherapy-resistance of human cancers. Our previous study revealed an induction of pi-class glutathione S-transferase (Yp) mRNA in the kidney 3 h after administration of Fe-NTA. In the present study, expression of GST isozymes were further investigated in the Fe-NTA-induced RCCs of rats which are characterized by (1) high incidence of metastasis and invasion, (2) high incidence of tumour-associated mortality, and (3) possible involvement of reactive oxygen species in carcinogenesis. In the Fe-NTA-induced RCCs, the levels of alpha-class GST (Ya) mRNA and proteins were markedly decreased with no apparent change in the copy number of the gene. In contrast, GST-Yp mRNA and proteins were significantly increased in the RCCs while the total GST enzymatic activity was decreased. Immunohistochemical analysis revealed intense staining of GST-Yp not only in the primary RCCs and its metastatic sites, but also in their non-tumorous part of proximal tubules. The contrastive expression of GST isozymes in this renal carcinogenesis model suggests an alteration of its transcription mechanisms and warrants further investigation of this particular detoxifying enzyme from the viewpoint of reactive oxygen species-induced carcinogenesis.

Animals↗
PubMed1998

Expression of alpha-fetoprotein and prostate-specific antigen genes in several tissues and detection of mRNAs in normal circulating blood by reverse transcriptase-polymerase chain reaction.

BACKGROUND: alpha-Fetoprotein (AFP) and prostate-specific antigen (PSA) in serum are widely used as tumor markers in the evaluation of prognosis and management of patients with hepatocellular carcinoma and prostate cancer, respectively. To establish the molecular diagnosis of cancer, reverse transcriptase polymerase chain reaction (RT-PCR) for AFP and PSA was used to identify circulating cancer cells in the blood of cancer patients. Here, we examined the tissue-specificity of AFP and PSA and tested whether AFP and PSA are suitable targets in the detection of certain cancer cells by RT-PCR using peripheral blood samples. METHODS: Tissue specificity of AFP and PSA was analyzed by Northern blotting and RT-PCR. Probes for AFP and PSA were hybridized with poly A+ RNAs from 50 human tissues. RT-PCR for AFP and PSA mRNA was performed using several cancerous tissues and normal tissues and peripheral blood cells from seven healthy volunteers. RESULTS: Broad expression of AFP was observed in several tissues and a large amount of AFP mRNA was found in fetal liver. PSA was expressed in prostate, salivary gland, pancreas and uterus. By RT-PCR, AFP and PSA mRNA were detected in several tumors, including salivary pleomorphic adenoma, hilar bile duct carcinoma, pancreatic carcinoma, transitional cell carcinoma of urinary bladder and thyroid papillary carcinoma. Furthermore, AFP and PSA mRNAs were frequently detected by RT-PCR, even in peripheral blood cells from healthy volunteers. CONCLUSIONS: Neither AFP nor PSA showed tissue-specific expression. AFP and PSA mRNA were detected in several diseased and non-diseased tissues and normal circulating blood by RT-PCR.

Adenoma, Pleomorphic↗