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Biomedical subjects

T Azuma

Publications and source records attributed to T Azuma.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1993

Neurosteroids in cerebrospinal fluid in neurologic disorders.

In order to investigate the role of "neurosteroids" in the central nervous system (CNS), cerebrospinal fluid (CSF) levels of dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) were determined by radioimmunoassay in 57 patients with various neurologic disorders and 26 patients with non-neurologic disorders. The content of CSF DHEA and DHEAS in patients with Guillain-Barré syndrome (GBS), and the content of CSF DHEAS in patients with carcinomatous meningitis were significantly higher as compared to non-neurological control patients. These changes may be explained by the breakdown of blood-nerve barrier in these disorders. A significant positive correlation was observed between DHEAS and total protein in CSF. In males but not females, a negative correlation was observed between CSF DHEAS and aging. The level of CSF DHEAS, but not DHEA, was significantly higher in males than in females.

Adult↗
PubMed1993

Specific IgG autoantibodies are potent inhibitors of autoreactive T cell response to phytohemagglutinin-activated T cells.

PHA-activated human T cells express MHC class II molecules and have been shown to stimulate autoreactive T cells in autologous mixed lymphocyte reaction (T-T AMLR). We now demonstrate that normal human serum can dramatically suppress the proliferative response in T-T AMLR. The inhibitory factor was detected in the IgG fraction, and the activity was found to be mediated through the F(ab')2 portion of the IgG molecule, implying that the inhibitor could be specific. All homologous as well as autologous sera tested contained the inhibitory activity. Human serum was also found to suppress allogenic MLR stimulated by PHA-activated T lymphocytes but not allogenic MLR stimulated by nonactivated PBMC, indicating that the mechanism of inhibition is related to PHA activation of the stimulator cells. Moreover, pretreatment of the PHA-activated T lymphocytes with human serum resulted in a significant inhibition of T-T AMLR, as opposed to pretreatment of nonactivated PBMC, indicating that PHA-activated stimulators are functionally involved in the inhibition. Cytofluorometric analysis revealed that autologous IgG specifically binds to PHA-activated T lymphocytes and not to nonactivated CD3+ T cells. Furthermore, serum absorbed by PHA-activated T lymphocytes substantially lost its inhibitory activity whereas serum absorbed by nonactivated PBMC did not, suggesting that a surface molecule(s) expressed during activation of the stimulator cells is involved in the inhibition. The addition of human serum later in the culture period (> 3 days) resulted in a marked decrease in inhibition, implying that the presence of IgG in the early recognition phase of T-T AMLR is essential for maximum inhibitory effect. These results raise the possibility that natural autoantibodies present in normal human IgG may play an important role in regulating immune response mediated by autoreactive T cells.

Autoantibodies↗
PubMed1993

Anterior sagittal anorectoplasty as a redo operation for imperforate anus.

Based on the idea of transsphincteric approach by Peña, we applied anterior sagittal anorectoplasty (ASARP) as a redo operation in 10 patients, who present moderate to severe fecal incontinence postoperatively. Those patients exhibited anal opening located anteriorly to the center of contraction of external sphincter muscles. Operation is begun with making a circumferential skin incision in the mucocutaneous junction around the anal opening, extending posteriorly along the median line to the center of the external sphincter muscles. Upon confirming the vertical muscle and the external sphincter muscles, the rectal tube, being dissected free, is mobilized backward to be placed at the center of the vertical muscles and enclosed by the muscle. After the operation, an improvement was noted in either clinical symptoms or scores, being particularly marked for incontinence and staining scores. Anorectal manometry and barium enema studies also showed a significant improvement. These results provide ample justification of ASARP as a redo operation for imperforate anus being worthwhile trying in properly selected patients with poor anorectal function following the primary operation.

Anus, Imperforate↗
PubMed1993

Elimination of HIV-infected cells by lymphocytes armed with a bifunctional antibody to gp120 of HIV and CD3.

The T-cell receptor (TCR) can acquire a new antigen binding site by treatment with a bifunctional antibody (BFA) prepared with mAb against a specified antigen and an epitope of the TCR. Lymphocytes armed with BFA directed to CD3 and an HIV antigen were able to eliminate all HIV antigen-positive cells during incubation with a mixture of HIV-infected and uninfected cells. HIV antigen-positive cells even from persistently infected cells were undetectable with immunofluorescence staining although HIV genes were detectable by polymerase chain reaction (PCR) amplification indicating that only dormantly infected or low producer cells, if any, survived. This suggests that HIV antigen-positive cells could be eliminated by administration of BFA-armed lymphocytes leaving HIV patients with only dormantly infected or low producer cells.

Antibodies, Bispecific↗
PubMed1993

Mutations of the chloramphenicol acetyl transferase transgene driven by the immunoglobulin promoter and intron enhancer.

Transgenic mice containing the chloramphenicol acetyl transferase (CAT) gene driven by the immunoglobulin (Ig) VH promoter and the heavy chain intron enhancer were prepared to increase our understanding of the mechanism responsible for somatic mutation. The transgene showed similar tissue specificity in terms of expression as endogenous Ig genes. Hybridomas were prepared after multiple immunization of a transgenic mouse with (4-hydroxy-3-nitrophenyl)acetyl-chicken gammaglobulin, a thymus-dependent antigen. We analyzed mutations in the CAT coding region as well as in the region 5' upstream of the promoter after amplification of DNA using the PCR followed by sequencing of cloned DNA. Mutation detection enhancement gel electrophoresis was also used to detect mutations. Only a single band was observed in PCR products from the region 5' upstream of the promoter and from the enhancer, whereas in those from the CAT coding region, three out of 11 hybridomas showed multiple bands. In DNA sequences of the CAT coding region from these three hybridomas, a total of six nucleotide substitutions were observed, but none in the region 5' to the promoter. The results of DNA sequencing and the electrophoresis were in good agreement, suggesting that mutation occurred only in the CAT gene but not in the region 5' to the promoter or the enhancer. The rate of mutation in the CAT gene was estimated to be 1.6 x 10(-5) per base pair per cell division, which was a lower limit of the rate for somatic mutation reported for Ig genes. Location and distribution of mutations were similar to that of the Ig gene, suggesting that (i) mutation in the CAT gene was induced by a mechanism similar to that occurring in the Ig gene and (ii) the mutator mechanism can operate in a non-Ig gene provided it is flanked by the VH promoter and heavy chain intron enhancer.

Animals↗
PubMed1993

Pepsinogen C gene polymorphisms associated with gastric body ulcer.

This study was aimed to investigate the association of restriction fragment length polymorphisms (RFLPs) for pepsinogen genes with peptic ulcer disease. Eighty unrelated controls, 61 patients with gastric ulcer, and 57 patients with duodenal ulcer were studied. No genetic polymorphisms for pepsinogen A were detected by EcoRI digestion in Japanese subjects but a 100 base pairs insertion-deletion RFLP for the pepsinogen C gene was observed. The allele frequencies of the large (3.6 kilobase EcoRI fragment) and the small fragment (3.5 kilobase EcoRI fragment) were 80.6% and 19.4% respectively in controls, 55.4% and 44.6% in patients with gastric body ulcer, 79.4% and 20.6% in patients with gastric angular ulcer, 71.4% and 28.6% in patients with gastric antral ulcer, and 75.4% and 24.6% in patients with duodenal ulcer. The allele frequency of the small fragment was significantly higher in patients with gastric body ulcer than in controls and in patients with gastric angular or antral ulcer. The genotypes which possessed the small fragment were significantly more frequent in patients with gastric body ulcer (78.4%) than in controls (33.8%) and in patients with gastric angular or antral ulcer (37.5%). These results suggest that there is a significant association between the genetic polymorphism at the pepsinogen C gene locus and gastric body ulcer, and that the pepsinogen C RFLP is a useful marker of the genetic predisposition to this disorder. These results also indicate genetic heterogeneity of gastric ulcer disease, and suggest that the pepsinogen C RFLP may be a useful subclinical marker to explain the differences in genetic aetiologies of gastric body ulcer and gastric angular or antral ulcer.

Adult↗
PubMed1993

Purification of Gnathostoma spinigerum larval antigens by monoclonal antibody affinity chromatography.

An immunoaffinity column was prepared by coupling a partially purified Gnathostoma spinigerum-specific IgG1, MAb SK-6C4 (5 mg/ml) to CNBr-activated Sepharose 4B. Ten milliliters of approximately 0.3 mg/ml of crude soluble G. spinigerum larval antigens (GsAL3) were loaded onto the affinity column at a flow rate of about 5 ml/hour. Elution of the bound antigens was accomplished using 50 mM diethylamine-HCI containing 0.15 M NaCL, pH 11.5. The average amount of eluted antigens obtained by one passage of crude GsAL3 (1-4 mg) through 4 to 8 ml of column matrix was 143 micrograms (range, 67 - 414 micrograms). The minimal amount of purified GsAL3 detectable by ELISA using MAb SK - 6C4 (100 micrograms/ml) was 50 ng/ml. The SK - 6C4 affinity-purified GsAL3 was found to be relatively pure and immunologically specific as determined by SDS-PAGE and Western blotting, respectively.

Animals↗