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Biomedical subjects

T Tamura

Publications and source records attributed to T Tamura.

At least 505 records · Page 28Linked to original sources
PubMed1996

Long-term outcome of percutaneous transluminal coronary angioplasty and coronary bypass surgery for multivessel coronary artery disease.

We studied the short- and long-term outcomes of 97 patients treated with percutaneous transluminal coronary angioplasty (PTCA) and 72 patients treated with coronary artery bypass graft surgery (CABG) for multivessel coronary artery disease in a single hospital in 1989. Patients treated with CABG had a higher angina class, a higher incidence of diabetes mellitus and a greater extent of the disease. Complete revascularization was achieved in 61 patients (85%) with CABG and in 45 patients (46%) with PTCA (p < 0.001). Initial success of PTCA and CABG was obtained in 95% and 94% of the patients with PTCA and CABG, respectively. Actuarial survival rates at 5 years were similar (96% in the PTCA group; 94% in the CABG group). Fewer patients suffered from cardiac death or myocardial infarction in the CABG group than in the PTCA group, but this difference was not significant. The rate of survival free from death, myocardial infarction, CABG and repeat PTCA, was significantly higher in the CABG group than in the PTCA group (85% vs 48%; p < 0.001). These results suggest that CABG provides a favorable long-term outcome in patients with multivessel coronary artery disease and that PTCA provides a similar outcome in these patients when applied to suitable lesions, although more patients who undergo PTCA require repeat procedures.

Aged↗
PubMed1996

Cleavage specificity of coxsackievirus 3C proteinase for peptide substrate (2): Importance of the P2 and P4 residues.

Coxsackievirus 3C proteinase (3Cpro) cleaves between Gln and Gly, but additional amino acids are required to constitute a cleavage site. To investigate the additional sequence requirements, cleavages of the peptide substrate, and its derivatives were examined. Substitutions of each residue from the P2 to P5 positions showed the importance of the P2 Phe and P4 Ala for recognition by 3Cpro.

3C Viral Proteases↗
PubMed1996

Cleavage specificity of coxsackievirus 3C proteinase for peptide substrate.

The substrate requirements of coxsackievirus 3C proteinase (3Cpro) were investigated on the C-terminal side of the scissile bond using C-terminal truncated peptides of the substrate peptide Ac-EALFQGPPV. Not only the Gln-Gly bond of Ac-EALFQG-NH2 but also the C-terminal amide group of Ac-EALFQ-NH2 was hydrolyzed by 3Cpro, suggesting that the essential residues for cleavage by coxsackievirus 3Cpro would exist within the N-terminal 5 residues.

Amino Acid Sequence↗
PubMed1996

Proliferation of granulosa and thecal cells in germinal disc and non-disc regions during follicular growth in Japanese quail (Coturnix coturnix japonica): bromodeoxyuridine incorporation in situ.

Proliferation of granulosa and thecal cells was analysed during ovarian follicular growth in laying Japanese quail. The birds were injected intraperitoneally with bromodeoxyuridine (BrdU) 10 or 4 h before ovulation, that is, before or after a preovulatory LH surge, respectively, and incorporation of BrdU by follicular tissues was detected immunocytochemically. Cells labelled with BrdU were seldom seen in the most immature follicles in the ovarian cortex, whereas many granulosa and thecal cells were labelled with BrdU in medium-sized white yolky follicles (approximately 13.3% and 14.4% in granulosa and theca layers, respectively). Ten and four hours before ovulation, the granulosa cells in the germinal disc and non-disc regions of the third largest yellow yolky follicle (F3) were labelled with BrdU (approximately 8.4% and 9.4% in germinal disc; 6.1% and 9.0% in the non-disc region), but only those in the germinal disc region were labelled (approximately 5.4% and 4.0%) in the largest yellow yolky follicle (F1). The percentage of thecal cells labelled with BrdU 4 h before ovulation was significantly higher than the percentage labelled 10 h before ovulation, and was higher in F3 (approximately 11.7%) than in F1 follicles (approximately 5.4%) 4 h before ovulation. These results show that proliferation of granulosa and thecal cells occurs in both germinal disc and non-disc regions in growing follicles, but when a follicle matures proliferation is reduced and in the case of granulosa cells it is restricted to the germinal disc region.

Animals↗
PubMed1996

Homocysteine and folate concentrations in blood from patients treated with hemodialysis.

Plasma homocysteine and plasma and erythrocyte folate concentrations before and after hemodialysis were measured in 31 patients with ESRD. Homocysteine and folate were measured by HPLC-fluorometric and microbiological methods, respectively. The mean plasma homocysteine level declined from 36.8 to 24.2 mumol/L during hemodialysis, indicating that homocysteine can be partly removed by hemodialysis (P < 0.0001). Mean plasma folate concentration before hemodialysis was 46.4 nmol/L and decreased to 25.9 nmol/L after hemodialysis (P < 0.0001), whereas mean erythrocyte folate concentration did not change (1295 and 1385 nmol/L before and after hemodialysis, respectively). Plasma folate concentrations showed a significant negative correlation with homocysteine concentrations before and after hemodialysis (r = -0.53, P < 0.003, and r = -0.59, P < 0.001, respectively). Furthermore, there were significant negative correlations between plasma homocysteine and erythrocyte folate concentrations both before (r = -0.60, P < 0.0005) and after hemodialysis (r = -0.49, P < 0.005). All patients had homocysteine concentrations over 12.0 mumol/L before hemodialysis, and only three had homocysteine concentrations lower than 12.0 mumol/L after hemodialysis. Although significant correlations existed between homocysteine and folate concentrations, the majority of the patients in this study appeared to have adequate folate nutriture as assessed by blood folate concentrations. It remains to be determined whether patients with ESRD have an altered homocysteine metabolism.

Adult↗
PubMed1996

Effects of cisplatin on erythropoietin production in rats.

The effects of cisplatin on erythropoietin (EPO) production were investigated in comparison with the effects of phenylhydrazine in rats. Cisplatin (4.5 mg/kg i.p. bolus) decreased red blood cell count (RBC), hematocrit (Hct) and hemoglobin concentration (Hgb) for 14 days after dosing. These decreases were accompanied with increases of blood urea nitrogen (BUN) and serum creatinine (s-CRE). Both serum EPO concentration and kidney EPO mRNA content were significantly decreased in cisplatin-treated rats. On the other hand, phenylhydrazine (10 mg/kg p.o. once a day for 8 days) decreased RBC, Hct and Hgb, and increased serum EPO concentration and kidney EPO mRNA content. Phenylhydrazine had little effect on BUN or s-CRE. These results suggest that a suppression of EPO production is involved in the pathophysiology of cisplatin-induced renal anemia and that measurement of serum EPO concentration and kidney EPO mRNA content is available for distinguishing renal anemia from hemolytic anemia.

Anemia↗
PubMed1996

Antineutrophil cytoplasmic autoantibodies in patients with systemic sclerosis.

Perinuclear type of antineutrophil cytoplasmic antibodies (p-ANCA) have been found in patients with periarteritis nodosa, Churg-Strauss arteritis, or pauci-immune idiopathic crescentic glomerulonephritis. Recently, the association of p-ANCA and normotensive renal failure, in patients with systemic sclerosis (SSc), was reported. We have studied the incidence of p-ANCA in patients with SSc and have investigated its relationship to clinical and laboratory findings. Sera from 77 patients with SSc were examined by the indirect immunofluorescence (IIF) test, employing an ethanol-fixed human neutrophil and enzyme-linked immunosorbent assay, using purified myeloperoxidase (MPO) as an antigen (MPO-ELISA). The sera from seven patients (9.1%) were p-ANCA positive, by both IIF and MPO-ELISA. One patient died from systemic necrotizing angiitis but the remaining six patients have shown no symptoms of systemic vasculitis or of renal involvement. There was a tendency for patients positive for p-ANCA (anti-MPO antibody) to also be positive for other autoantibodies, such as anti-Sc1-70 antibody, anti-centromere antibody, anti-microsome antibody, anti-thyroglobulin antibody and rheumatoid factor. Although the incidence of p-ANCA (anti-MPO antibody) is low in patients with SSc, and its clinical significance in SSc needs further investigations, this could be a serological marker for certain symptoms in SSc.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1996

Decreased beta 2-adrenergic receptor-mRNA and loricrin-mRNA, and increased involucrin-mRNA transcripts in psoriatic epidermis: analysis by reverse transcription-polymerase chain reaction.

Psoriatic hyperproliferative epidermis is characterized by a decreased beta 2-adrenergic adenylate cyclase response as well as by altered differentiation markers that include decreased loricrin and increased involucrin. Using a quantitative reverse transcription-polymerase chain reaction, we analysed the expression of beta 2-adrenergic receptor-mRNA, loricrin-mRNA, and involucrin-mRNA in the epidermis of five patients with psoriasis vulgaris. The mRNAs of the beta 2-adrenergic receptor and loricrin in the involved epidermis were significantly decreased, by 0.35-fold (P < 0.01) and 0.55-fold (P < 0.05) respectively, compared with uninvolved epidermis. In contrast, the involucrin mRNA expression of the involved epidermis was significantly increased, by 3.77-fold (P < 0.01). No significant difference in beta-actin mRNA transcripts was detected between the involved and the uninvolved epidermis. These results indicate that the altered expression of the beta 2-adrenergic receptor, loricrin, and involucrin, in the psoriatic involved epidermis, is associated with different amounts of each mRNA transcripts.

Actins↗
PubMed1996

[Detection of rifampicin-resistant strains of Mycobacterium tuberculosis by a non-radioactive PCR-SSCP method].

PCR-SSCP method to detect genetic mutations in rpoB gene as a marker of rifampicin-resistance was developed by Telenti et al., and we have modified it applying non-radioactive PhastSystem for more practical use in the detection of rifampicin-resistance of Mycobacterium tuberculosis. PCR products amplified with the primers specific to rpoB gene using extracted DNA from 89 strains of M. tuberculosis were sequenced and the amino acid sequences were morphism was determined by the PhastSystem. The bands were stained by silver staining. Among 89 strains of M. tuberculosis, 43 were confirmed as rifampicin-resistant (RFPr) and 46 were rifampicin-sensitive (RFPs) by the culture on the drug-containing media. All of the 43 RFPr strains had one or more mutations in the DNA sequence of rpoB gene, while none of the RFPs strains had such mutations. However, by PCR-SSCP, only 20 out of 43 RFPr strains showed clear differences in the band pattern of electrophoresis from that of RFPs strains. Other 23 RFPr strains had only slight differences in the band pattern of the PCR-SSCP from that of RFPs strains. But it was noticed that the main bands of RFPr strains were distinguishable from the main bands of RFPs strains even their patterns were similar. Thus, it is possible to apply a non-radioactive PCR-SSCP for the detection of rifampicin resistance of M. tuberculosis with further improvement of the condition of gel electrophoresis or staining techniques.

Amino Acid Sequence↗
PubMed1996

[Ten-year follow-up of percutaneous transluminal coronary angioplasty].

The long-term efficacy of percutaneous transluminal coronary angioplasty (PTCA) was evaluated in 124 patients who underwent PTCA between October 1982 and June 1985. Seventy-six patients had their proximal coronary arteries completely revascularized by PTCA (including repeat PTCA) and follow-up angiography showed the vessels were patent 3 to 6 months after the last intervention (group A). The other 48 patients showed incomplete revascularization (group B). The 10-year event-free survival rates from cardiac death and non-fatal myocardial infarction were 89.7% in group A and 93.5% in group B, respectively. Survival rates free from cardiac death, myocardial infarction, coronary bypass surgery, and repeat angioplasty for new lesions were 82.5% and 62.7%, respectively (p < 0.001). Ninety-nine percent of patients in group A and 79.5% of patients in group B were asymptomatic at the follow-up. Coronary angiography was performed in a total of 22 patients (19 patients in group A, 3 in group B). In group A, myocardial infarction occurred in one patient 8 years after PTCA. The infarct-related lesion seemed to be the same as the previous PTCA lesion. Although the other 20 PTCA lesions were all patent without progression, nine significant and new lesions were found on the coronary angiograms. Successfully revascularized vessels remained patent for over 10 years, but new lesions sometimes occur in segments other than the previously treated segment.

Aged↗
PubMed1996

[Effects of retinal intrinsic dopamine on the in in vivo electroretinogram of rabbits].

The effects of intravitreal injection of nomifensine, a potent dopamine uptake blocker, on the electroretinogram (ERG) were investigated in rabbit. Nomifensine enhanced the amplitude of the oscillatory potentials at 100 microM (intravitreal concentration) and 300 microM (p < 0.05), but it attenuated the oscillatory potentials at 1,000 microM (p < 0.01). Nomifensine attenuated the amplitude of the scotopic b-wave at 100 microM and 1,000 microM (p < 0.05), leaving the peak latency of the scotopic b-wave unaltered at all concentrations tested (30, 100, 300, 500 and 1,000 microM). Neither the amplitude nor the peak latency of the dark-adapted a- and b-waves elicited by bright stimuli was altered at any nomifensine concentration tested. 1 microM dopamine and 30 microM nomifensine together, each of which is insufficient to alter either of the scotopic b-wave or the oscillatory potentials when applied alone, reduced the scotopic b-wave and enhanced the oscillatory potentials. These results suggest that intrinsic dopamine release in the retina is large enough to alter the ERG.

Animals↗
PubMed1996

[D1 receptor mediates dopamine-induced enhancement of electroretinographic oscillatory potentials].

The inhibitory action of SCH 23390 (SCH, D1-antagonist) or sulpiride (SUL, D2-antagonist) on the dopamine-induced enhancement of the electroretinographic oscillatory potentials was examined in anesthetized albino rabbits. Enhancement of the oscillatory potentials by intravitreal dopamine (50 microM intravitreal concentration) injection was blocked by a simultaneous intravitreal injection of SCH (20 microM) but not by SUL (50 microM, 100 microM). These results suggest that D1-receptor is mainly responsible for the dopamine-induced enhancement of the oscillatory potentials.

Action Potentials↗
PubMed1996

[Acute appendicitis caused by mucorales in a patient with severe aplastic anemia: report of an autopsy case].

A male patient with severe aplastic anemia was admitted for bone marrow transplantation. While waiting for a donor, high doses of methylprednisolone, anabolic steroid and granulocyte colony stimulating factor were given without response. Deferoxamine was administered for prophylaxis of hemochromatosis because of high level of ferritin. Acute right lower abdominal pain and pyrexia developed. A diagnosis of acute appendicitis was made and appendectomy was performed. The histopathological examination of the resected appendix revealed necrotizing hemorrhagic appendicitis with numerous hyphae of Mucorales. Though anti-fungal agent (amphotericin B) administration was continued, he subsequently developed ileo-cecal abscess and eventually died due to myoglobinuric nephropathy caused by extensive necrosis of the iliopsoas muscle. Autopsy revealed dissemination of hyphae of Mucorales in lungs, kidneys, large vessels and muscle of the bilateral lower limbs. Systemic vascular invasion and embolization of fungal hyphae were also observed. However, culture of exudate sampled from ileocecum yielded no Mucorales. It was emphasized that antemortem diagnosis and effective anti-fungal treatments are essential for the management of intestinal mucormycosis. The relation ship between mucormyocosis and deferoxamine was also discussed.

Acute Disease↗
PubMed1996

Membranous nature of premacular vitreous cortex in the human eye.

To characterize the morphologic nature of the premacular vitreous, we examined the posterior vitreous of 24 normal autopsy eyes without posterior vitreous detachment (PVD) by biomicroscopy and scanning electron microscopy (SEM). For biomicroscopic observation, the vitreous was stained with fluorescein and immersed in water. The posterior portion of the eyeball was then desiccated and examined by SEM. The vitreous cortex was extremely thin in the premacular area, and premacular liquefied lacuna was invariably seen in front of the thin vitreous cortex by biomicroscopic observations. In SEM the premacular vitreous cortex appeared to be a cellophane-like membrane overlying the retina at x40 approximately 100 magnification. A meshwork structure could be seen in the cellophane-like membrane at the magnification of approximately x1000. The diameter of fibers in the meshwork was compatible with that of vitreous collagen. We confirmed that the premacular vitreous cortex was of a membranous nature distinct from the vitreous gel in eyes without PVD.

Aged↗
PubMed1996

Effects of efonidipine, nicardipine and captopril on proteinuria in aged spontaneously hypertensive rats.

Previous studies have shown that antihypertensive drugs attenuate the progression of proteinuria by their treatments from young age, but few have examined their effects on impaired renal function in older age. In the present study the calcium antagonists efonidipine ((+/-)-2-[benzyl (phenyl)amino]ethyl 1,4-dihydro-2,6-dimethyl-5-(5,5-dimethyl-2-oxo-1,3, 2-dioxaphosphorinan-2-yl)-4-(3-nitrophenyl)-3-pyridinecarboxyla te hydrochloride ethanol, CAS 111011-76-8, NZ-105) and nicardipine, and an angiotensin-converting enzyme inhibitor, captopril, were examined for their effects on heavy proteinuria in aged spontaneously hypertensive rats (SHR). Efonidipine (20 mg/kg), nicardipine (20 mg/kg) and captopril (30 mg/kg) were orally administered once a day for 4 weeks. The urinary protein excretion (UproE) increased with age (54.9 mg/kg/day at 24 weeks of age to 170.8 mg/kg/day at 36 weeks). The increased UproE was significantly suppressed by daily administration of efonidipine or captopril as compared to that in the non drug treated control group. The UproE in the nicardipine group was maintained at a slightly lower level than in the control. The histological examination showed that the damages of the kidneys were slightly suppressed by efonidipine and captopril. These findings indicate that efonidipine as well as captopril reduce proteinuria in aged SHR and the effect was stronger than that of nicardipine. This beneficial effect of efonidipine on proteinuria suggests its usefulness in antihypertensive therapy.

Aging↗
PubMed1996

[Treatment of postoperative nausea and vomiting with ondansetron in patients administered anti-neoplastic agents].

The antiemetic effect of ondansetron (a 5-HT3 antagonist) was evaluated in patients treated with intraperitoneally administered anti-neoplastic agents (cisplatin and mitomycin-C) during surgery for ovarian cancer. Anesthesia was induced with intravenous thiopental 5 mg x kg-1 and maintained with nitrous oxide 66% in oxygen and isoflurane. After surgery, 6 patients received a single intravenous dose of ondansetron 4 mg (group O), 6 others did not receive ondansetron (group C). Both groups received an intravenous dose of methyl-prednisolone 500 mg. An intravenous dose of metoclopramide 10 mg was provided in case of continued vomiting or at the patient's request as a rescue antiemetic. The incidence of vomiting was 13% in group O and 87% in group C (P < 0.05). Nausea scores (range 1-4) were significantly lower in group O as compared with group C at 4 h and 8 h after surgery. Total dose of metoclopramide was 20 +/- 13 mg (mean +/- SD) in group C and 2 +/- 4 mg in group O. Administration of anti-neoplastic agents during surgery caused severe nausea and vomiting after surgery and ondansetron prevented the occurrence of nausea and vomiting almost completely. We conclude that ondansetron is an effective antiemetic for preventing postoperative nausea and vomiting in patients administered anti-neoplastic agents.

Adult↗
PubMed1996

Strain differentiation and phylogenic relationships, in terms of base sequence of the ure B gene, of Helicobacter pylori.

We constructed a phylogenetic tree based on the nucleotide sequence of the ure B gene of Helicobacter pylori strains, amplified by polymerase chain reaction (PCR). We analyzed the tree in terms of the relationship between the PCR-restriction fragment length polymorphism (RFLP)-genotype and the sequevar. The main frame of ure B (928 bp) was amplified by PCR from 38 strains of clinical isolates and reference species. The amplified probes were sequenced and processed into matrix and phylogenic trees. Homogeneity of the strains of "intra-case" origin and heterogeneity in "inter-cases" was parallel to clustering on the phylogenic tree. Sequevars in a cluster showed an identical RFLP-genotype in one case, indicating the clonal origin of H. pylori flora in an individual.

Base Sequence↗