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Biomedical subjects

T Azuma

Publications and source records attributed to T Azuma.

At least 199 records · Page 11Linked to original sources
PubMed1994

Expression of the interleukin-6 (IL-6), IL-6 receptor, and gp130 genes in acute leukemia.

Expression patterns of interleukin-6 (IL-6), IL-6 receptor (IL-6R), and gp130 genes in 39 patients with acute myeloid leukemia (AML), in 23 patients with acute lymphoblastic leukemia (ALL), and in 7 patients with acute mixed lineage leukemia (AMLL) were studied by quantitative reverse transcriptase-polymerase chain reaction. Significant levels of IL-6 were expressed in 8 (21%) of 39 AML patients and in 2 (29%) of 7 AMLL patients, whereas in ALL, the expression of IL-6 was almost negligible. IL-6R was expressed in all patients with AML and AMLL, whereas only half of ALL patients expressed low levels of IL-6R as compared with those with AML and AMLL. However, gp130 was ubiquitously expressed in all the leukemia patients, and there was no significant difference in gp130 expression among AML, ALL, and AMLL. Significant correlation was observed between the expression of IL-6R and gp130 in AML. When tested for in vitro response to IL-6, the leukemic cells from 3 of 7 AML, none of 3 ALL, and both of 2 AMLL patients significantly responded to IL-6, showing the correlation between the expression levels of IL-6R and gp130 and the responsiveness of leukemic cells to IL-6. These results showed that quantitation of IL-6R and gp130 expression by reverse transcriptase-polymerase chain reaction is useful for the rapid prediction of the responsiveness of leukemic cells to IL-6, especially in cases of administration of IL-6.

Adolescent↗
PubMed1994

Isolation of the bile canalicular actin-myosin II motor.

Cytoskeleton-rich canalicular membranes (CCMs) with preserved cytoskeleton and demembranated CCMs, consisting only of cytoskeletal elements, were used to examine the relationship of pericanalicular microfilaments, myosin II phosphorylation, and canalicular contraction. The components of CCMs were visualized by fluorescence microscopy using the filamentous actin probe rhodamine-phalloidin and by electron microscopy, before and after incubation in 1 microM Ca2+/1 mM ATP (contraction solution). Canalicular contraction (luminal closure) was evaluated by morphometric analysis. Myosin II was extracted from CCMs, purified by immunoprecipitation, and analyzed on Western blots. In sequential experiments, autoradiographs of gels from [gamma-32P]-ATP-treated CCMs in the presence or absence of Ca2+ were examined after 0.25, 0.50, 1, 2, 3, 5, and 10 min, and the effects of W7 (a calmodulin antagonist) and ML9 (a myosin light chain kinase inhibitor) were evaluated. The results showed that phosphorylation of the 20-kDa protein was low in controls but enhanced beginning 0.25-0.50 min after addition of contraction solution. Both W7 and ML9 significantly inhibited this reaction and inhibited canalicular contraction. The results indicate that phosphorylation of the regulatory 20-kDa myosin light chain of canaliculus-associated myosin II coincides with or precedes contraction of the canaliculus. We conclude that the canalicular contractile apparatus is composed of actin filaments and a myosin II motor.

Actins↗
PubMed1994

The gene responsible for LEC hepatitis, located on rat chromosome 16, is the homolog to the human Wilson disease gene.

We identified the rat homolog to the human Wilson disease (WD) gene as the gene responsible for hepatitis (hts) in the Long Evans Cinnamon (LEC) rat. A genetic study using fifty-three backcross progenies showed that the rat WD gene detected by Southern blotting using the human WD gene as a probe was tightly linked to the hts phenotype of the LEC rat with no recombination. LEC is a transcriptionally deficient mutant because no transcript of the rat WD gene could be found in the LEC rat by Northern blotting. This rat WD gene was mapped to 16q12.23-12.3 by fluorescence in situ hybridization and mouse x rat somatic cell hybrid analysis.

Animals↗
PubMed1994

Secretion of human intracellular aspartic proteinase cathepsin E expressed in the methylotrophic yeast, Pichia pastoris and characterization of produced recombinant cathepsin E.

The human gastric cathepsin E (CTSE), a dimeric aspartic proteinase, was expressed in the methylotrophic yeast Pichia pastoris by placing the CTSE cDNA under the control of the methanol inducible alcohol oxidase promoter. The human CTSE expressed in P. pastoris was secreted into the culture medium as an active enzyme directed by its native signal sequence despite its intracellular localization in mammalian cells. The time course analysis of the culture supernatant of the P. pastoris transformant expressing human CTSE revealed that the recombinant human CTSE was secreted as a 90 kDa molecule and then converted via an 84 kDa intermediate to an 82 kDa mature molecule. A large-scale culture of the transformant was performed in a high cell density fermentor and the recombinant human CTSE was highly purified from the culture supernatant. The purified recombinant cathepsin E had the molecular mass of 82 kDa with the amino-terminal sequence starting with Ile37 of the sequence deduced from its cDNA sequence, suggesting that the human cathepsin E was accumulated in the culture supernatant as mature dimeric enzyme. The result of endoglycosidase-H digestion followed by Western blot analysis of the purified recombinant cathepsin E suggested that the human cathepsin E expressed in P. pastoris received N-linked high-mannose type glycosylation. The enzymatic properties of the recombinant enzyme were comparable to those of natural human CTSE.

Base Sequence↗
PubMed1994

Comparison of somatic mutation frequency among immunoglobulin genes.

We analyzed the frequency of somatic mutation in immunoglobulin genes from hybridomas that secrete anti-(4-hydroxy-3-nitrophenyl)acetyl (NP) monoclonal antibodies. A high frequency of mutation (3.3-4.4%) was observed in both the rearranged VH186.2 and V lambda 1 genes, indicating that somatic mutation occurs with similar frequency in these genes in spite of the absence of an intron enhancer in lambda 1 chain genes. In contrast to the high frequency in J-C introns, only two nucleotide substitutions occurred at positions -462 and -555 in the 5' noncoding region in one of the lambda 1-chain genes and in none of the other three so far studied. Since a similar low frequency of somatic mutation was observed in the 5' noncoding region of inactive lambda 2-chain genes rendered inactive because of incorrect rearrangement, this region may not be a target or alternatively, may be protected from the mutator system. We observed a low frequency of nucleotide substitution in unrearranged V lambda 1 genes (approximately 1/15 that of rearranged genes). Together with previous results (Azuma T., N. Motoyama, L. Fields, and D. Loh, 1993. Int. Immunol. 5:121), these findings suggest that the 5' noncoding region, which contains the promoter element, provides a signal for the somatic mutator system and that rearrangement, which brings the promoter into close proximity to the enhancer element, should increase mutation efficiency.

Animals↗
PubMed1994

High prevalence of neutralizing activity to Helicobacter pylori cytotoxin in serum of gastric-carcinoma patients.

Helicobacter pylori infection is causally related to chronic type-B gastritis, and may also be associated with an increased risk of gastric carcinoma. Vacuolating cytotoxin, which is an 87-kDa protein secreted by H. pylori, induces eukaryotic cell vacuolation in vitro. To determine whether there is an association between H. pylori vacuolating cytotoxin and gastric carcinoma, we investigated several characteristics of H. pylori infection, i.e., isolation of H. pylori from gastric biopsies, antibodies specific for H. pylori, detection of neutralizing activity to vacuolating cytotoxin in serum and immunological detection of cytotoxin by serum. Out of 6 sera from gastric-carcinoma patients, all showed the neutralizing activity to vacuolating cytotoxin, in contrast to 3 of 5 sera from peptic-ulcer patients. Normal individuals showed no neutralizing activity. All sera possessing the neutralizing activity recognized an 87-kDa protein band by Western blot analysis. Our results confirmed that cytotoxin-neutralizing activity in human sera was associated with immunodetection of an 87-kDa protein. To further evaluate neutralizing activity in serum from gastric-carcinoma patients, we retrospectively analyzed frozen-stocked serum samples from 22 gastric-carcinoma patients. Sera from 21 of these 22 patients exhibited neutralizing activity. These sera were also checked for antibodies to H. pylori, using an ELISA; 16 sera showed positive results. Our results indicate that detection of cytotoxin-neutralizing activity in sera is strongly associated with H. pylori infection, and probably with gastric carcinoma, and is also of interest in the diagnosis of H. pylori infection.

Adult↗
PubMed1994

Histological studies on the rheumatoid synovial membrane irradiated with a low energy laser.

The beneficial effects of low energy laser irradiation on rheumatoid arthritis (RA) joints have been reported, but the mechanisms of action of low energy lasers in RA are unclear. The synovial membrane in cases of RA was studied histologically to observe the effects of low energy laser irradiation. Fourteen knee joints of RA cases, which had been scheduled for arthroplasty, were irradiated with a gallium-aluminium-arsenide (Ga-Al-As) laser (790 nm in wavelength and 10 mW of output power) prior to the surgical operation, at six points of the external aspect of the knee joint for 80 seconds at each points once a day for 6 days. On the day following the last irradiation, pieces of synovial membrane from the lateral irradiated area and from the median nonirradiated area as a control were resected during the arthroplasty. The histological findings of the irradiated synovial membrane showed flattening of epithelial cells, decreased villous proliferation, narrowed vascular lumen, and less infiltration of inflammatory cells compared with those of nonirradiated synovia. The evaluation of slides was done in a blinded manner, and significant differences was seen by Wilcoxon's t-test (P < 0.01). Histological findings suggested that the low energy laser irradiation induced suppression of inflammation in the synovial membrane of RA.

Arthritis, Rheumatoid↗
PubMed1994

The effect of donor-specific transfusion and cyclosporin A on small bowel transplantation in the rat.

Pre-transplant blood transfusions are given as a means of desensitization to reduce the required dose of cyclosporin A (CsA). In this study, the effect of pretransplant blood transfusion on host survival and T-cell function against alloantigen were investigated. Male Lewis rats (RT1(1)) were used as the recipients in all experiments, and male DA rats (RT1a) were used as the blood and small bowel donors, and as a source of allogeneic stimulator cells. Male BUF rats (RT1b) were used as donors of third party blood, and of allo-stimulator cells in a delayed-type hypersensitivity (DTH) response. In our experimental design, Lewis rats were divided into the following groups according to the type of administration: (1) a donor-specific blood transfusion (DST) 8 days preoperatively and a concurrent 5-day course of CsA at 10 mg/kg per day; (2) a nonspecific third party blood transfusion (NST) and CsA at 10 mg/kg per day from day 8 to day 4 preoperatively; (3) CsA alone from day 8 to day 4 preoperatively; (4) DST alone 8 days preoperatively; or (5) no treatment, being the control group. Postoperative treatment consisted of CsA at 2.5 mg/kg per day for 30 days. Rats conditioned with NST plus CsA, CsA alone, DST alone, and the untreated control rats survived for 7.2 +/- 1.2, 9.0 +/- 2.2, 6.8 +/- 0.4, and 7.4 +/- 1.6 days, respectively. In contrast, the five rats conditioned with DST plus CsA survived for 100 days or more.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

A case of quadruplet pregnancy containing complete mole and three fetuses.

A case of a quadruplet pregnancy containing a complete mole and three fetuses is reported. A 29-year-old Japanese woman who had received clomiphene therapy was delivered of a complete mole, one dead and two living fetuses, and three placentas. Deoxyribonucleic acid fingerprint analysis proved the androgenesis of molar tissue and the trizygosity of the three fetuses.

Adult↗
PubMed1994

A case of ovarian Brenner tumor with stromal estrogenic activity.

An 88-year-old menopausal Japanese female suffering from atypical genital bleeding received a left oophorectomy for a tumor of the left ovary. A vaginal smear before removal of the tumor revealed high estrogenic activity. The patient's ovarian tumor was a benign Brenner tumor and contained theca-like cells in its stroma. The pathological findings relating to these theca-like cells suggested their estrogenic activity, and a vaginal smear after removal of the tumor revealed that estrogenic activity had disappeared.

Aged↗
PubMed1994

Sevoflurane inhibited beta-adrenoceptor-G protein bindings in myocardial membrane in rats.

The effects of sevoflurane on the beta-adrenoceptor (beta AR) system, consisting of the receptor, stimulatory guanosine triphosphate (GTP) binding protein (Gs), and adenylate cyclase (AC), were studied in rat myocardial membrane. Cyclic adenosine monophosphate (cAMP) production rate was measured as cAMP generation stimulated by l-isoproterenol, guanosine 5"-O-(3-thiotriphosphate) (GTP gamma S), and forskolin, respectively. The receptor studies were performed by using the dihydroalprenolol ([3H]DHA) binding method. Nonspecific binding was determined in the presence of l-propranolol. beta AR binding capacity determined by the maximum number of binding sites (Bmax) and the dissociation constant (Kd) for [3H]DHA were calculated. beta AR affinity for agonists was assessed by an inhibition constant (Ki), calculated from the concentration of l-isoproterenol to produce half-maximum inhibition of [3H]DHA binding (IC50). At 2.0 mM sevoflurane, cAMP production rate was significantly depressed by 87.1% +/- 4.8% with l-isoproterenol and by 79.4% +/- 7.0% with GTP gamma S, but not significantly depressed by forskolin. In the presence of 0-2.0 mM sevoflurane, Kd for [3H]DHA and Ki for l-isoproterenol increased in a concentration-dependent manner, whereas Bmax remained unchanged. The ratio of high affinity state against the high and low affinity state of the adrenoceptor decreased significantly from 0.60 +/- 0.15 to 0.35 +/- 0.12. We conclude that sevoflurane might depress the beta AR signal transduction system by reducing ligand-receptor bindings and disrupting the relationship between the receptor and Gs.

Anesthetics↗
PubMed1994

Vacuolating cytotoxin production by Helicobacter pylori isolates from peptic ulcer, atrophic gastritis and gastric carcinoma patients.

OBJECTIVE: We investigated the production of vacuolating cytotoxin by Helicobacter pylori isolates from patients with peptic ulcer, atrophic gastritis or gastric carcinoma in order to examine the pathophysiological significance of vacuolating cytotoxin in these diseases. METHODS: H. pylori was isolated from 18 patients (five with peptic ulcers, seven with atrophic gastritis and six with gastric carcinoma). Culture supernatants of H. pylori isolates, concentrated 20-fold, were serially diluted and then analyzed for cytotoxin activity semi-quantitatively using A431 cells as indicator cells. The relative activity of vacuolating cytotoxin was defined according to the maximum dilution. RESULTS: Cytotoxin production was observed in two out of five, six out of seven and six out of six isolates from peptic ulcer, atrophic gastritis and gastric carcinoma patients, respectively. The mean relative activity was calculated as 0.80, 2.71 and 2.50 in CONCLUSION: These results suggest that vacuolating cytotoxin-producing H. pylori is strongly associated with both atrophic gastritis and gastric carcinoma.

Adult↗
PubMed1994

Removal of pesticides from wastewater at golf courses using plants (removal by mung beans; Phaseolus radiatus L).

Many studies have been done on the removal of pollutants from wastewater using aquatic plants. Water hyacinth has been the most widely-used plant, and systems using water hyacinth are well-established. These systems, however, have a few problems in their practical use. In a previous paper, we proposed a new system that could be used as a substitute for a conventional system or, as a secondary system to assist the conventional one. Mung beans will be used to remove pollutants in this system. In the previous experiment, the removal characteristics of nutrient salts such as NO2-, NO3-, NH4+ and phosphorus salts from wastewater in residential areas were examined. Mung beans exhibited good characteristics for removing these nutrient salts. At present, pesticides used at golf courses have become a severe environmental problem polluting water supplies. The purpose of this study was, therefore, to verify whether our new system using mung beans was also effective in removing pesticides from wastewater at golf courses. An experiment was conducted on seven different pesticides. They were three insecticides; Diazinon, Fenitrothion and Chlorpyrifos, three fungicides; Captan, Isoprothiolane and Chlorothalonil, and a herbicide; Simazine. The experimental results showed that, under experimental conditions, the pesticides were rapidly removed and that they exhibited no harmful effects on the growth of the mung beans. Mung beans may be used, therefore, to remove pesticides from wastewater at golf courses although further research is needed.

Fabaceae↗
PubMed1994

Compressed allograft chips for acetabular reconstruction in revision hip arthroplasty.

We report the results of 24 acetabular reconstructions in which cemented polyethylene cups and tamped corticocancellous allografts were used for severe acetabular bone deficiency. Eleven hips had type-II (cavitary) bone deficiency and 13 had type-III (combined) defects. At a mean follow-up of 5.8 years, two components had migrated more than 5 mm and had accompanying radiolucent zones of more than 2 mm width. A radiolucency 5 mm wide was also seen in zone III of an acetabular implant which had not migrated. None of the patients had required revision because of loosening or infection.

Acetabulum↗