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Biomedical subjects

T Tamura

Publications and source records attributed to T Tamura.

At least 271 records · Page 15Linked to original sources

Sporichthya brevicatena sp. nov.

A strain was isolated from soil that formed short chains of aerial mycelium dividing into motile spores on an agar medium, but not substrate mycelium. The organism had menaquinone 9(H8), LL-diaminopimelic acid in the cell wall amino acids and a DNA G + C content of 71 mol%. On the basis of the morphological and chemotaxonomic characteristics and phylogenetic analysis, this strain was classified into the genus Sporichthya. DNA-DNA hybridization revealed that the strain differed from the known species, Sporichthya polymorpha. Therefore, a new species, Sporichthya brevicatena sp. nov., is proposed. The type strain is S. brevicatena YU720-21T (= IFO 16195T).

Actinomycetales↗

Clinical and immunological characterization of patients with systemic sclerosis overlapping primary biliary cirrhosis: a comparison with patients with systemic sclerosis alone.

Limited cutaneous systemic sclerosis (lSSc) or CREST syndrome is sometimes complicated by primary biliary cirrhosis (PBC). To characterize the clinical and immunological features of patients with SSc overlapping PBC (SSc-PBC), the clinical and laboratory data of 11 SSc-PBC were studied. Since all of the SSc-PBC were lSSc, the features of SSc-PBC were compared with those of 266 patients with lSSc alone. The sera from SSc-PBC showed a significantly higher positivity for anti-centromere antibody (ACA) (p < 0.0005) and higher reactivity to centromere protein-C. Although SSc-PBC more frequently exhibited calcinosis and telangiectasia (p < 0.05), there was no statistical difference in other features of CREST syndrome. There was no statistical difference in other scleroderma-related features either. SSc-PBC were more frequently complicated with Sjögren syndrome (p < 0.05). The most prominent feature of SSc-PBC was a higher incidence of ACA than in lSSc alone.

Adult↗

[Resuscitation from the viable but nonculturable state of Helicobacter pylori].

It is well known that the change of state from the culturable to not culturable on pathogenic organisms could easily occurred. These states of bacteria were so called viable but nonculturable (VNC). The coccoid form of H. pylori is seems to be in this state. The possibility of resuscitation of H. pylori was examined in vitro. The coccoid form bacteria was treated with Ammonium Sulfate and heat shock before culture, and cultured in Brucella broth containing, sodium pyruvate, laked human erythrocyte and serum. The growth of the rod spiral form was found in the coccoid form bacteria, and further the bacteria could grow on blood agar and Skirrow agar as well as the original strain. It was strongly suggested that the resuscitation from VNC state of cells to culturable form consists of two processes, stimulation and supplemented of appropriate nutrition.

Bacteriological Techniques↗

Gender difference in cord serum ferritin concentrations.

We measured cord serum ferritin concentrations in a total of 255 infants (116 females and 139 males), and evaluated the association between these values and various neonatal as well as maternal characteristics. The mean ferritin concentration in females (166 +/- 110 microg/l) was significantly higher than that in male infants (123 +/- 77 microg/l). The gender differences in ferritin were significant within groups of infants with fetal growth restriction, those who weighed <3,000 g, those whose mothers were African Americans or <25 years old. Maternal serum ferritin concentrations at 36 weeks of gestation significantly correlated with cord serum ferritin of male infants (r = 0.32, p < 0.001), whereas the association was not significant for females (r = 0.09, p > 0.41). Although the mechanism of the gender difference is unknown, it may be important to consider the sex of neonates when evaluating their iron nutriture immediately after birth.

Adult↗

Gender-related differences in myocyte remodeling in progression to heart failure.

Gender-related differences responsible for the better prognosis of females with heart failure have not been clearly established. To address this issue, we investigated potential gender-related differences in myocyte remodeling in spontaneously hypertensive heart failure rats. Echocardiograms and myocyte growth were compared between males and females at compensated (2, 4, and 6 months) and decompensated (18 months in males and 24 months in females) stages of cardiac hypertrophy. Although left ventricular diastolic dimensions did not differ significantly between failing male and female rats, fractional shortening declined significantly only in failing males. Myocyte cross-sectional area did not change after 4 months of age in both genders, which is likely to be responsible for the absence of a change in left ventricular wall thickness during the progression to heart failure. Myocyte volume and cross-sectional area were significantly larger in males than females at 2, 4, and 6 months of age, although there were no significant differences at the failing stage. Reduced adaptive hypertrophic reserve was observed in males, which is likely to contribute to the higher morbidity and mortality of males with chronic heart failure.

Animals↗

Gene transfer of mitochondrially targeted glutathione reductase protects H441 cells from t-butyl hydroperoxide-induced oxidant stresses.

Increased generation of reactive oxygen species (ROS) and low levels of antioxidants may cause morbidity in premature infants on supplemental oxygen. Glutathione (GSH)-dependent antioxidant systems protect against ROS, and regenerating GSH from GSH disulfide (GSSG) by the flavoenzyme GSH reductase (GR) is essential for the optimal function of this system. Previously, we have observed enhanced resistance to t-butyl hydroperoxide (t-BuOOH) in Chinese hamster ovary cells stably transfected with a vector (leader sequence GR [LGR]) for human GR cDNA that contained a functional synthetic mitochondrial targeting signal. The present studies were designed to investigate adenovirus-mediated gene transfer of LGR to H441 cells and resistance of such cells to t-BuOOH. Adenovirus-mediated transfection of H441 cells with LGR increased total GR activities more than 11-fold (mitochondria more than 10-fold and cytosolic more than 7-fold) and protected against t-BuOOH cytotoxicity, as indicated by lower fractional release of cellular lactate dehydrogenase (LDH) than was observed in wild-type untransfected cells (CON) or in cells transfected with a control gene (human manganese superoxide dismutase in the antisense orientation [DOS]) (*LGR 6.6 +/- 1.7; DOS 16 +/- 1.8; CON 16.6 +/- 0.7% LDH release). In addition, cells transfected with LGR retained higher GSH/GSSG ratios (*LGR 66 +/- 0.4; DOS 47 +/- 1; CON 52.6 +/- 2.3) and released less GSH + GSSG to the media in response to challenge with t-BuOOH (*LGR 0.05 +/- 0.01; DOS 0.08 +/- 0.01; CON 0.07 +/- 0.01 nmol/mg of protein) than did wild-type cells or cells transfected with a control vector, indicating an enhanced ability of the LGR cells to reduce GSSG formed in response to exposure to t-BuOOH. In conclusion, adenovirus-mediated gene transfer of LGR enhanced cellular GR activities and protected H441 cells from oxidant stresses.

Cell Line, Transformed↗

HP33: hepatocellular carcinoma-enriched 33-kDa protein with similarity to mitochondrial N-acyltransferase but localized in a microtubule-dependent manner at the centrosome.

Using a new subtraction method and chemically induced rat hepatocellular carcinomas, we identified a hepatocellular carcinogenesis and hepatocyte proliferation-related gene designated hp33 that encoded a 33-kDa protein. The predicted protein was similar to the bovine aralkyl N-acyltransferase and arylacetyl N-acyltransferase. HP33 was restrictively expressed in the liver and kidney, and its gene expression was stimulated in the regenerating liver as well as in hepatocellular carcinoma. Interestingly, it was demonstrated in various hepatic cells that HP33 was localized in regions surrounding the centrosome, where mitochondria were not concentrated. Moreover, its centrosomal localization was evident in the interphase but not in the mitotic phase of the cell cycle. The centrosomal localization of HP33 was dependent on microtubules, and ectopically expressed HP33 was seen at centrosomes even in fibroblasts, which do not exhibit a typical staining pattern of HP33. The centrosomal localization of HP33 became invisible by nocodazole treatment, whereas the mitochondrial staining pattern was not affected by it. In vitro cosedimentation experiments using purified microtubules indicated that HP33 bound to MTs directly and that its MT-binding ability was dependent on the C-terminal basic domain of the protein. These results suggest that, different from early predictions based on its primary structure, HP33 has a growth- and carcinogenesis-related function that may be independent of mitochondrial function.

Acyltransferases↗

Long-term clinical and echocardiographic outcome in patients with mitral stenosis treated with percutaneous transvenous mitral commissurotomy.

Long-term follow-up after percutaneous transvenous mitral commissurotomy (PTMC) is limited. Ninety-four middle-aged (51+/-9 years) mitral stenosis patients who underwent successful PTMC were followed up with annual echocardiography for 6.1+/-1.4 years. PTMC success was defined as either mitral valve area (MVA) >1.5 cm2 or a MVA of more than twice the pre-procedural value, together with no worsening of mitral regurgitation >grade 2+. Mitral valve replacement (MVR), worsening of congestive heart failure (CHF), and thromboembolism were sought for survival analysis. Restenosis was defined as loss of more than 50% of the initial procedural MVA gain. Functional limit of daily activities was assessed through a questionnaire. The study population was divided into group 1 (post-procedural MVA >2.0 cm2), group 2 (MVA > 1.5 cm2 and < or = 2.0 cm2) and group 3 (MVA < or = 1.5 cm2). The 6-year survival with freedom from MVR, CHF, thromboembolism, and combined events (MVR+CHF) was 92%, 95%, 91%, and 88%, respectively. No group 1 patient experienced MVR or CHF. Restenosis was predominant in group 3. Deterioration of daily activities during follow-up was not observed in group 1; however, it was significant in group 2 (p<0.05) and group 3 (p<0.001). These results demonstrated that patients who attained a large MVA (>2.0cm2) immediately after PTMC maintained their procedural benefit with less clinical complication and with less limitation of daily activity.

Adult↗

Long-term outcome of percutaneous transluminal coronary angioplasty and coronary artery bypass grafting in patients with end-stage renal disease.

This study was conducted to investigate therapeutic methods for end-stage renal disease (ESRD) by retrospectively analyzing in-hospital outcome and long-term outcome in patients who underwent either percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG). Ninety-two patients underwent PTCA and 47 underwent CABG, and the initial success rates were 87% and 85%, respectively. As major in-hospital complications, in the PTCA group 1 died (1%), 2 required emergency CABG (2%), and 2 had Q-wave myocardial infarction (2%); in the CABG group, 7 died (15%) and 3 had Q-wave myocardial infarction (6%). As for the long-term outcome, although there were no differences in the incidence of death or the incidence of cardiac death between the 2 groups, the cumulative proportion of patients free of death, myocardial infarction, CABG and repeat PTCA was lower in the PTCA group, which was mainly due to a higher incidence of repeat PTCA in that group. The incidence of cardiac death was low for both groups among the patients attaining complete revascularization. Twenty-three percent of the patients required cross-over implementation of PTCA and CABG. In conclusion, it is necessary to aim for complete revascularization using both treatments for a better prognosis in patients with ESRD.

Angioplasty, Balloon, Coronary↗

Transient splenomegaly in acute pancreatitis.

Serial changes in splenic volume of 25 patients (18 men and seven women; 53.4 +/- 20.8 years old, range 25-83) with acute pancreatitis who underwent CT examinations were retrospectively studied. Abdominal CT was performed within 3 days after the onset and there was at least one follow-up CT examination after this time. The percentage changes of splenic volume in the first (4-30 days) and second (31-100 days) follow-up CT were calculated. Splenic volume increased in the first follow-up CT (mean +/- SD: 197.8 +/- 121.0 cm3) compared with the initial CT (124.8 +/- 70.0; p < 0.0001), and then decreased in the second follow-up CT (179.7 +/- 100.7; p < 0.002). The average splenic volume increased 65.5 +/- 88.7% (range -10.4-377.4%) between the initial and first follow-up CT examinations. Five of 25 cases (20%) in whom size of spleen increased more than twice had severe acute pancreatitis (p < 0.05), complicated pseudocyst requiring surgical drainage (p < 0.05), pleural effusion (p < 0.01), splenic vein thrombosis or compression (p < 0.05) and longer hospital stay (p < 0.02) compared with patients with a smaller increase in splenic volume. In conclusion, transient splenomegaly was commonly seen in acute pancreatitis, especially in severe or complicated cases. Congestive splenomegaly caused by obstruction or stenosis of the splenic vein and non-specified acute splenitis were suspected of contributing to the transient splenomegaly.

Acute Disease↗

Spontaneous pinealoma in a male Crj:CD (SD) IGS rat.

A pinealoma (benign) was found in a 61-week-old male Crj:CD (SD) IGS rat. The neoplasm was located between the cerebral hemispheres and the cerebellum. Histologically, the tumor cells consisted of two cell types: large, pale-staining cells and small dark-staining cells. A fibrovascular stroma divided the tumor cells into incomplete lobules or nest structures. Relatively numerous mitoses were noted in the tumor cells. Ultrastructurally, the tumor cells contained dense-cored vesicles, approximately 120 nm in diameter.

Animals↗

Time course observation of thyroid proliferative lesions and serum levels of related hormones in rats treated with kojic acid after DHPN initiation.

Time course changes in thyroid proliferative lesions as well as related hormone levels in the blood of male F344 rats given N-bis(2-hydroxypropyl)nitrosamine (DHPN: 2800 mg/kg body weight, single s.c. injection) as an initiation treatment followed by pulverized basal diet containing 0% (Group 2), 2% (Group 3) or 4% (Group 4) kojic acid (KA) were examined at Weeks 1, 2, 4, 8 and 12. As an untreated control group (Group 1), rats were given basal diet for 13 weeks and examined in the same manner. Serum T3/T4 levels in the DHPN + 2% KA and DHPN + 4% KA groups were significantly reduced as compared with the DHPN-alone group at each time point. Serum TSH levels in both DHPN + KA groups were significantly increased at each time point in a treatment period-dependent manner from Weeks 1 to 12, and the extent of elevation was more remarkable in the DHPN + 4% KA group. At Week 2, there were no statistically significant intergroup differences in liver T4-UDP-GT activities on a milligram microsomal protein basis. Histopathologically, no thyroid proliferative lesions were observed in the untreated control group or the DHPN-alone group. However, diffuse follicular cell hypertrophy and decreased colloid in the thyroid were apparent in all rats of the DHPN + KA groups at each time point. In addition, focal follicular cell hyperplasias and adenomas of the thyroid were observed at high incidence in the DHPN + 2% KA group from Week 4 and in the DHPN + 4% KA group from Week 8. Multiplicities of focal follicular cell hyperplasias and adenomas of the thyroid in the DHPN + 2% KA group were significantly greater than those in the DHPN + 4% KA group at Week 8. In the pituitary, an increase in the number of TSH producing cells with expanded cytoplasm was apparent from Weeks 4 to 12 in both DHPN + KA groups. These results strongly suggest that thyroid proliferative lesions were induced by KA administration due to continuous serum TSH stimulation through the negative feedback mechanism of the pituitary-thyroid axis, resulting from depression of serum T3 and T4.

Adenoma↗

Localized pericarditis with calcifications mimicking a pericardial tumor.

A 62-year-old man was admitted with increasing palpitations. Radiography of the chest demonstrated a calcified mass. Magnetic resonance imaging revealed compression of the right ventricle by a tumor. At the time of cardiac catheterization, the coronary arteries were found not to supply blood flow of the mass, and no dip-and-plateau pattern was seen in the right ventricular pressure measurements. At the time of surgery, the mass was found to be a focal calcified thickening of the pericardium containing only pus. The thickening resembled an oval pericardial tumor. Microbiologic examination of the pus revealed Propionibacterium acnes.

Calcinosis↗

[Adverse reactions to autologous peripheral blood stem cell transplantation in patients over 65 years old].

We compared the outcomes of autologous peripheral blood stem cell transplantation (auto-PBSCT) for two groups: one composed of 6 patients over 65 years of age, and the other, of 8 younger patients. Transfused CD34-positive cells and CFU-GM counts, days to achieve a neutrophil count of over 500/microliter after transplantation, days to achieve a platelet count of over 50,000/microliter, and blood transfusion times were similar in both groups. Organ toxicity also appeared similar in both groups, but no severe adverse reactions (WHO grade/4) were observed. Poor performance status due to advanced tumors improved in some patients after PBSCT. We concluded that PBSCT is tolerable in patients over 65 years of age and useful as salvage therapy.

Age Factors↗