Search PubMed⌕ Search

Biomedical subjects

M Miyata

Publications and source records attributed to M Miyata.

At least 199 records · Page 11Linked to original sources
PubMed1996

Interleukin-6 induces proliferation of rat hepatocytes in vivo.

BACKGROUND/AIMS: The aim of this study was to assess the effect of interleukin-6 (IL-6) on the proliferation of hepatocytes and to study the interaction between IL-6 and hepatocyte growth factor (HGF) in vivo. METHODS: IL-6 was injected at a dose of 200 micrograms/mg subcutaneously into rats every day for 14 days. Liver and blood samples were obtained at 1, 3, 7 and 14 days during IL-6 administration. Hepatocyte proliferative activity of sera was measured using 3H-thymidine incorporation into cultured rat hepatocytes. To evaluate the proliferative activity of the hepatocytes in tissue sections, hepatic DNA content and immunostaining of the liver tissue sections for proliferating cell nuclear antigen (PCNA) were performed. Plasma HGF levels were measured using specific EIA. In addition, total RNA was extracted from the liver and expression of HGF mRNA was detected by RT-PCR. RESULTS: The DNA contents of liver taken from IL-6-treated rats were increased during IL-6 administration compared with untreated rats. Sera taken from IL-6-treated rats at various intervals during administration also significantly increased 3H-thymidine incorporation by cultured rat hepatocytes compared with sera from untreated rats, suppressing 3H-thymidine incorporation at day 1 and 3 by anti-HGF antibody. IL-6 itself did not increase 3H-thymidine incorporation. Increased expression of PCNA in these hepatocytes was noted from 1 day after IL-6 administration, and at 14 days, the number of PCNA-positive cells was sevenfold greater than in the livers of untreated rats. However, plasma HGF levels showed a peak at day 1, decreased gradually from day 3, and became undetectable by day 14. HGF mRNA expression in livers of IL-6-treated rats was suppressed from day 3 to day 14 of IL-6 administration. CONCLUSIONS: These data show that IL-6 induces an early phase of liver cell growth in vivo and suggest that an increase level of HGF mediates this effect.

Animals↗
PubMed1996

Vestibular neurectomy: a histological and clinical study of results.

Posterior fossa vestibular neurectomy has become one of the most effective surgical procedures for control of vertigo symptoms in Menière's disease. A small group of patients continue to have vertigo and demonstrable vestibular function by electronystagmography (ENG) post-operatively. Another group of patients may have no vertigo, despite residual vestibular function on caloric testing. In an effort to correlate histological findings with clinical outcome, nerve biopsies were taken from seven patients undergoing vestibular neurectomy. Fibre counts of nerve biopsies were compared with clinical, audiometric and ENG results. Results of this study demonstrate that complete reduction of vestibular response (on caloric testing) and clinical cure of vertigo can be obtained despite a variable number of nerve fibres at vestibular neurectomy.

Adult↗
PubMed1996

Apolipoprotein E allele-specific antioxidant activity and effects on cytotoxicity by oxidative insults and beta-amyloid peptides.

The apolipoprotein E (APOE) E4 allele is associated with Alzheimer's disease, cardiovascular disease, and decreased longevity. To probe the mechanism of these associations, cell lines were created which secrete each apoE isoform. ApoE conditioned media, purified apoE, and commercially obtained apoE protected B12 cells from hydrogen peroxide cytotoxicity with E2 > E3 > E4. Physiological levels of apoE protected cells from beta-amyloid peptides, while higher doses of apoE led to increased cytotoxicity. E2 > E3 > E4 possessed antioxidant activity, and apoE bound certain metal ions. The decreased antioxidant activity of E4 could contribute to its association with Alzheimer's disease, cardiovascular disease and decreased longevity.

Alleles↗
PubMed1996

Protective effect of beraprost sodium, a stable prostacyclin analogue, in development of monocrotaline-induced pulmonary hypertension.

Experimental pulmonary hypertension (PH) was induced by a single injection of monocrotaline (MCT), a pyrrolizidine alkaloid extracted from Crotalaria spectabilis. The effect of beraprost sodium, a stable prostacyclin analogue, on the development of MCT-induced PH in rats was studied. Chronic administration of beraprost sodium at a dose of 30 micrograms/kg/day initiated on the same day as MCT injection decreased the degree of PH determined by weight ratio of right ventricular free wall to that of left ventricle plus septum depending on the duration of administration. Although the injection of prostaglandin E1 (PGE1) at a dose of 200 micrograms/kg/day initiated 1 week after MCT injection did not decrease the degree of PH significantly, beraprost sodium administration at doses of 30 and 100 micrograms/kg/day decreased the degree of PH significantly. The cytoprotective effect of beraprost sodium against endothelial cell (EC) damage is believed to be involved in inhibiting development of PH in MCT-injected rats. The amounts of cytokines such as interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor (TNF) produced by alveolar macrophages decreased in accordance with the inhibiting effect of beraprost sodium on development of PH, indicating that beraprost sodium inhibited the development of PH in MCT-injected rats not only through its effect of vasodilation and anti-platelet aggregation in pulmonary circulation but also through its antiinflammatory effects.

Alprostadil↗
PubMed1996

Isolation and characterization of a new rat P450 (CYP3A18) cDNA encoding P450(6)beta-2 catalyzing testosterone 6 beta- and 16 alpha-hydroxylations.

A cytochrome P450 cDNA, encoding a new form of CYP3A protein, was isolated from a liver cDNA library of a male rat using anti-P450(6)beta-1 and anti-P450(6)beta-2 antibodies and the CYP3A2 cDNA. The cDNA (CYP3A18 cDNA) consisted of 1987 nucleotides, in which were contained an open reading frame of 1491 bp (corresponding to 497 amino acids), 5'-(59 bp) and 3'-noncoding regions (437 bp). The deduced amino acid sequence of CYP3A18 cDNA was completely identical in the first 27 N-terminal residues of P450(6)beta-2 previously isolated by us (Nagata et al. J Biochem 1990: 107, 718-725) from livers of rats treated with dexamethasone, and also shared higher extents of similarity with hamster CYP3A10 (78.5%) than with rat CYP3As previously sequenced (66.3-69.3%). Northern blot analyses indicated a male-dominant expression of this new CYP3A mRNA and enhanced expression in dexamethasone-or pregnenolone-16 alpha-carbonitrile (PCN)-treated, but not phenobarbital-or 3-methylcholanthrene-treated rats. Expressed CYP3A18 protein in COS-1 cells migrated at a position identical to that of purified P450(6)beta-2 on sodium dodecyl sulfate-acrylamide gel electrophoresis and catalyzed 16 beta- and 6 alpha-hydroxylations of testosterone. In contrast to CYP3A1 and CYP3A2, cytochrome b5 was not essential for maximal catalytic activities of recombinant CYP3A18 protein. These results, together with ontogenic profiles of CYP3A18 mRNA and P450(6)beta-2 protein, indicate that the newly isolated CYP3A18 cDNA encodes P450(6)beta-2 in rat liver.

Amino Acid Sequence↗
PubMed1996

Distribution of transforming growth factor-beta and its receptors in gastric carcinoma tissue.

The distribution of the three mammalian isoforms of transforming growth factor (TGF)-beta (TGF-beta 1, -beta 2, and -beta 3) as well as their signaling receptors, TGF-beta type I and type II receptors (T beta R-I and T beta R-II, respectively), in gastric carcinoma tissue was examined by immunohistochemistry using specific antibodies. Tissue specimens were obtained from 25 cases of gastric carcinoma, which were classified into two groups according to Lauren's classification, i.e. 15 cases of diffuse carcinoma and 10 cases of intestinal carcinoma. In normal gastric mucosa apart from carcinoma nests, all of TGF-beta 1, -beta 2, -beta 3, T beta R-I and T beta R-II were clearly demonstrated in fundic glands. In sharp contrast, none of them was detectable in surface mucous cells. In carcinoma cells, strong staining for TGF-beta 1, -beta 2 and -beta 3 was obtained only in diffuse-type carcinoma. In particular, carcinoma cells scattered as single cells or small nests had a tendency to show strong staining for TGF-betas. The receptors tended to be distributed concomitantly with the ligands, and diffuse-type carcinoma showed stronger receptor staining than intestinal-type carcinoma. In cancer stroma, TGF-betas and receptors were detected in both diffuse and intestinal types, but the area with positive staining was wider and more dispersed in diffuse-type carcinoma than in intestinal carcinoma. These results suggest that TGF-beta may contribute in part to the variety of histogenesis and mode of progression of gastric carcinoma.

Adenocarcinoma↗
PubMed1996

[Isolation and analysis of amino acid sequence of V3 region of HIV-1 from patients with HIV-infection in Hiroshima].

Isolation of HIV-1 was tried in PBMCs separated from 27 blood samples which were sent to Hiroshima Prefectural Institute for Health & Environment Science for anti-HIV antibody-test. 18 samples were positive for HIV-isolation (4 samples were Rapid/High type, 12 samples were Slow/Low type and 2 samples were intermediate). Compared with clinical stages of patients, samples from patients in CDC-II were 64% (14/22) positive and those in CDC-IV were 100% (3/ 3) positive in HIV-isolation. Improvement of the methods is to be required to isolate HIV from the samples of patient in the latent phase. Removal of CD8 positive cells from PBMCs of patients did not affect the efficiency of HIV-isolation by our methods. Three parts in amino acid sequence of V3 region in proviruses were different between Rapid/High type isolated and Slow/Low type isolates. The difference of amino acid may be related to the different phenotypes of the two viruses.

Amino Acid Sequence↗
PubMed1996

3DFT-flash MR imaging of pancreatic cancer with gadopentetate dimeglumine.

PURPOSE: We evaluated the usefulness of dynamic 3-dimensional Fourier transformation (3DFT) fast low angle shot (FLASH) MR imaging using gadopentetate dimeglumine (Gd-DTPA) to assess the extent of pancreatic cancer. MATERIAL AND METHODS: Breath-hold 3DFT-FLASH MR images (20/4; 25 degrees flip angle; 7 partitions; 3-5-mm slice thickness) were obtained before the ++administration of 0.1 mmol/kg of Gd-DTPA, just after (early phase), and 1 and 2 min (late phases) after in 14 patients with pancreatic cancer. All patients underwent surgical removal or laparotomy. We compared the findings of T1-, T2-, and postcontrast T1-weighted spin-echo (conventional SE) and 3DFT-FLASH imaging with histologic or surgical findings. RESULTS: Dynamic MR images could delineate the pancreatic tumors more clearly than the conventional SE images, and were useful for diagnosing vessel invasion. The contrast-to-noise ratio between the pancreatic cancer and the surrounding pancreatic parenchyma was significantly higher with the dynamic 3DFT-FLASH image than with the conventional SE images (p<0.01). CONCLUSION: Dynamic 3DFT-FLASH MR imaging with Gd-DTPA is useful in delineating and evaluating the extent of pancreatic cancer.

Adult↗
PubMed1996

[Chemotherapy with low-dose consecutive cisplatin (CDDP) for patients with recurrent and distant metastasis of head and neck cancer].

Treatment with low-dose consecutive cisplatin (CDDP) was performed on six patients with recurrent and distant metastasis of head and neck squamous cell carcinoma. All patients were men, and their ages ranged from 64 to 86 years with an average of 75. Primary treatments were radiotherapy and surgery in three patients, chemotherapy and radiotherapy in two patients, and radiotherapy, regional chemotherapy and surgery in one patient. Two patients had laryngeal recurrent carcinomas, one patient had nasopharyngeal recurrent carcinoma, one patient had recurrent metastatic neck lymph node and two patients had distant metastasis (lung and brain). CDDP was administered over consecutive seven days, with a daily dose of 10mg/m2 as continuous drip infusion for 148 hours from day 1 to day 7. Four patients received two courses, while two patients received one course. The overall response rate was 33%, which was restricted to a partial response in two patients. These patients were still alive about one year after treatment. No toxic effect was observed. The present study indicated that low-dose consecutive CDDP was safe and efficacious for patients with recurrent head and neck squamous cell carcinoma.

Aged↗
PubMed1996

[Intravesical oxybutynin hydrochloride in the treatment of urge incontinence in the elderly].

PURPOSE: This study was carried out to determine the effectiveness of intravesical oxybutynin hydrochloride on urinary urge incontinence in elderly people. METHODS: The subjects consisted of 13 patients with an average age of 75 years who demonstrated uninhibited detrusor contraction on cystometrogram. The trial protocol consisted of a pretreatment cystometrogram followed by the intravesical administration of 10 ml solution containing 5 mg oxybutynin hydrochloride (pH 5.85). The urodynamic studies were repeated one hour later. RESULTS: The mean bladder capacity before and after one hour of intravesical oxybutynin hydrochloride was 161 +/- 62 ml and 196 +/- 71 ml (mean +/- 1 S.D., n.s.). The rate of improvement was 15.4% (2 cases) in all 13 patients. Four patients out of 13 patients continued intravesical administration of the solution twice daily. Urinary incontinence disappeared in two patients and incontinence was markedly decreased in one. In the remaining patient, urinary incontinence did not change because of increased residual urine. Three patients have continued this therapy over one years and no side effects were observed. In these patients, residual urine volume did not increase. CONCLUSION: It is suggested that intravesical oxybutynin hydrochloride is an effective option of therapy for intractable urge incontinence in elderly people, however, the immediate posttreatment cystometrogram was not predictive of the response to intravesical therapy on overactive bladder in the elderly.

Administration, Intravesical↗
PubMed1996

[Sleeve pulmonary arterial resection for bronchogenic carcinoma].

Two cases of bronchogenic carcinoma undergone left upper lobectomy (R 3) with bronchoplasty and sleeve pulmonary arterial resection via mid-sternotomy were reported. Both cases were squamous cell carcinoma originated in the orifice of the left upper lobe. Case 1 was stage IIIB (T2N3M0) bronchogenic carcinoma, its postoperative course was uneventful and died of distant lymphatic metastasis thirty-three months after operation. Case 2 was stage II (T2N1M0) bronchogenic carcinoma and its postoperative management was laborious because of hard expectoration of the sputum but is doing well fifteen months after operation. In order to preserve adequate pulmonary function and to maintain reasonable quality of life (QOL) for the patients with impaired pulmonary function, this angioplastic procedure seems to be acceptable. It is still under discussion to perform this procedure for the patients who would be able to withstand undergoing pneumonectomy, therefore we adopt this method only for every patient for whom it is difficult to maintain desirable QOL after pneumonectomy. Namely, for the patient whose predicted one second forced expiratory volume (FEV1.0) after pneumonectomy is less than 900 ml/m2, we'll be likely to try this angioplastic procedure at first.

Aged↗
PubMed1996

[A case of a patient with post-operative empyema due to Mycobacterium chelonae].

We reported a case of a thoracic empyema due to M. chelonae (Atypical Mycobacterium, group IV) after thoracic surgery. A 49-year-old male underwent right middle lobectomy for pulmonary metastasis of esophageal cancer. Postoperative course was complicated for intractable air leakage, and several procedures were tried before successful re-thoractomy. Seven days after re-thoractomy, mycobacterium was proved in pleural effusion. And later on M. chelonae was identified by DNA hybridization method. Therefore, open window thoracotomy was performed at once. M. chelonae disappeared 7 days after operation and the patient discharged on 40 postoperative days. Thoracic empyema by M. chelonae is rare, and only one case was reported in Japan so far. Present case was not combined with infectious pulmonary disease by some mycobacterium. Therefore it is most reasonable to suppose this intrathoracic infection developed through the thoracic drain. In conclusion, because of the M. chelonae toleranced for almost all anti-biotics including anti-tuberculous agents, except clarithromycin, the timing of surgical approach is important for the treatment of this infectious disease.

Carcinoma, Squamous Cell↗
PubMed1996

[Application of oculokinetic perimetry in examination of the eye].

Oculokinetic perimetry was performed using the same protocol at four health screening facilities to determine its usefulness for identifying visual field abnormalities including glaucoma during complete physical screenings in Japan. Ophthalmoscopy of the optic disc, 26-point oculokinetic perimetry (OKP), and applanation tonometry were performed in 2,768 eyes. If any one of the tests yielded an abnormal result, the eye was then examined with a Humphrey visual field analyzer (HVFA, program 30-2). After the tests were completed, the results were evaluated by ophthalmologists for evidence of primary open-angle glaucoma and normal tension glaucoma and were classified into one of 3 groups: confirmed glaucoma, suspected glaucoma, and no glaucoma. OKP detected abnormalities in the visual field in 96 eyes (3.5%). Of these 96 eyes, 29 eyes had confirmed glaucoma, 52 eyes were suspected of having glaucoma and 15 eyes had no glaucoma. The remaining 15 eyes had no glaucoma, but in 7 of them other ophthalmological disease was diagnosed. The sensitivity, specificity, positive predictive value, and negative predictive value of OKP for detecting glaucomatous visual field defect were 0.46, 0.99, 0.84 and 0.96, respectively. The high specificity and negative predictive value show that OKP is unlikely to produce false positive results, but its low sensitivity suggests that it is not suitable for the early detection of glaucoma. However, OKP identified advanced glaucoma and other ophthalmological diseases associated with visual field abnormalities, suggesting that it is a useful screening test.

Adult↗