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Biomedical subjects

S Takagi

Publications and source records attributed to S Takagi.

At least 397 records · Page 22Linked to original sources
PubMed1991

The A5 antigen, a candidate for the neuronal recognition molecule, has homologies to complement components and coagulation factors.

The A5 antigen is a neuronal cell surface protein of Xenopus presumed to be involved in the neuronal recognition between the optic nerve fibers and the visual centers. Analyses of cDNA clones revealed that the A5 antigen is a class I membrane protein containing two different internal repeats in the extracellular segment. The first repeat bears homology to domain III of complement components C1r and C1s, and the second repeat is homologous to the C1 and C2 domains of coagulation factors V and VIII. The mRNA for the A5 antigen was present in retinal ganglion cells and visual center neurons. Nonneuronal cells in the peripheral and central nervous systems did not express the mRNA for the A5 antigen.

Amino Acid Sequence↗
PubMed1991

Submucosal dissection of the esophagus: a case report.

A 38-year-old male was admitted to our hospital complaining of dysphagia, sore throat and fever. An upper GI series revealed a "double-barrelled" esophagus. Endoscopic examination of the esophagus showed multiple ulcers and mucosal bridges resulting from laceration of the submucosal layer. An acute ulcer of the stomach was also found. Fasting and total parenteral nutrition for several weeks failed to bring about any changes in the endoscopic findings. As treatment, the mucosal bridges throughout the esophagus were divided with a diathermy knife under endoscopic control. Soon after the procedure, the patient's symptoms disappeared completely, and the massive dissection of the esophagus had improved except for slight depressions.

Adult↗
PubMed1991

Generation and function of gamma delta T cells after allogeneic bone marrow transplantation in humans: comparison in absence or presence of HLA-matched or mismatched thymus.

We have observed two patients who exhibited an exclusive increase of delta TCS1+ subset of gamma delta T cells in the peripheral blood after bone marrow transplantation (BMT). In one case with severe combined immunodeficiency (SCID) who received haploidentical BMT from his father, gamma delta T cells appeared only after thymus transplantation. However, his T cell-mediated immunity remained severely defective despite the generation of T cells of donor origin. In the other case with aplastic anemia, delta TCS1- gamma delta T cells began to increase in the peripheral blood later. This indicates that the thymus is necessary for the generation of gamma delta T cells and that the delta TCS1+ subset is dominant in the early stages of their ontogeny. delta TCS1+ T cell lines were established from both patients, and allo-reactivity was investigated. The cell line from the latter case reacted to recipient cells in a mixed lymphocyte reaction, but did not show cytotoxity to the allogeneic cells including recipient cells. The other cell line, from the former case, did not react to either donor or recipient cells. This indicates that an intact thymus is needed for gamma delta T cells to acquire allo-reactivity. Both cell lines showed MHC non-restricted cytotoxity against NK-sensitive target cells.

Adolescent↗
PubMed1991

Deposition of fluoride on tooth surfaces by a two-solution mouthrinse in vitro.

A constant-composition fluoride (F) titration method was used to measure the amount of leachable F deposited on tooth surfaces in vitro by a 1-min rinse with a 228-ppm F solution (12 mmol/l sodium fluoride). The mean F uptake was 0.23 +/- (SE) 0.07 microgram/cm2, corresponding to less than 0.2% of the F contained in the rinse. The present study describes a new F rinse system that consisted of two solutions. Solution A contained a soluble calcium salt and a buffer. Solution B contained sodium fluorosilicate, a complex fluoride salt. When solutions A and B were combined, the free F ions produced by hydrolysis of fluorosilicate caused precipitation of calcium fluoride during the 1-min application time. The F uptake produced by the two-solution rinse was 4.36 +/- 0.16 micrograms/cm2, which was approximately 19 times greater than that produced by the sodium F rinse with the same F content. Since the cariostatic effects from F rinses are believed to derive from their ability to deposit labile F in the oral cavity, the two-solution rinse may be more efficacious than the rinses currently in use.

Calcium Chloride↗
PubMed1991

Exercise-induced phospholipid degradation in the equine skeletal muscle and erythrocytes.

To understand the pathogenesis of equine exercise-induced myopathies and hemolysis, changes of phospholipid peroxidation products in the equine middle gluteal muscle and erythrocytes following the high-speed treadmill exercise were studied. In the skeletal muscle, the peroxidized phosphatidylethanolamine (PE) were increased at 24 hours after the exercise. The malondialdehydes (MDAs) were also increased as the protein-bound MDAs following exercise. In the erythrocytes, the peroxidized PE were significantly decreased at 24 hours after the exercise. The protein-bound MDAs were significantly increased at 5 min after the exercise and returned to the base values at 24 hours after the exercise. These findings indicate that the PE is more susceptible to in vivo oxidative effects than the other phospholipid classes, and the accumulation of the protein-bound MDAs is considered to play some cytotoxic roles in the equine skeletal muscle and erythrocytes following exercise.

Animals↗
PubMed1991

Cytogenetic analysis of human bile for mutagenicity and co-mutagenicity.

Cytogenetic analysis was used to test whether or not human bile induced chromosome abnormalities in lymphocytes grown in culture. Bile was obtained from gallbladders resected for various reasons such as cholecystitis, cholelithiasis, polypus and cancers of the biliary tract, stomach and pancreas. After adding human bile to a final concentration of 25 microliters/ml or 12.5 microliters/ml, the culture medium was incubated at 37 degrees C for 72 hr. Air-dried slides were stained with conventional Giemsa and the numerical and structural chromosome abnormalities were scored. Positive and negative controls in terms of chromosome abnormalities were established by using 0.03 micrograms/ml mitomycin C (MMC) and 0.9% normal saline, respectively. Cytogenetic analysis was successfully performed in 6 out of 10 bile samples (60.0%). Bile alone did not induce numerical or structural chromosome abnormalities. Structural abnormalities increased significantly in the 25 microliters/ml bile + 0.03 micrograms/ml MMC group, compared with the 0.03 micrograms/ml MMC group: 36.0% vs. 20.7% in the chromatid-type gaps and breaks, 27.8% vs. 22.7% in the chromosome-type gaps and breaks, and 8.3% vs. 3.2% in the exchange-type abnormalities. It is likely that the interaction between bile and MMC is synergistic rather than additive.

Adult↗
PubMed1991

[Prophylactic antibiotics after transurethral resection of prostate].

We studied whether or not prophylactic use of antibiotics following transurethral resection of prostate (TUR-P) was needed. The subjects were 152 patients preoperatively passing sterile urine who underwent TUR-P. They were divided into three groups: 35 with no use of antibiotics (no prophylaxis group), 70 with one day use of antibiotics (one day-prophylaxis group) and 47 with use of antibiotics until pyuria disappeared (long term-group). The three groups did not differ in their rates of fever episodes (greater than or equal to 38.0 degrees C) during the first two weeks nor in the time of disappearance of pyuria. The no prophylaxis group and the one day-group differed statistically in their cumulative rates of bacteriuria (greater than 10(4) CFU/ml) on the postoperative third day: 4 patients (11.4%) in the no prophylaxis group and none in the one day group (p less than 0.01). On the 90th day, however, no significant difference was found in that rate: 22 patients (62.9%) in the no prophylaxis group and 32 patients (45.7%) in the one day group, 70% of the bacteria isolated from urine during the follow up were Gram positive cocci. The time to the elimination of pyuria was not influenced by the use of antibiotics. Our study suggests that postoperative antibiotics for patients passing sterile urine is not necessary following TUR-P.

Aged↗
PubMed1991

Primary structures of N-linked oligosaccharides of momordin-a, a ribosome-inactivating protein from Momordica charantia seeds.

The structures of the N-linked oligosaccharides of momordin-a, which is a ribosome-inactivating protein from the seeds of Momordica charantia, were analyzed. First, the N-linked oligosaccharides of this glycoprotein were liberated by hydrazinolysis. After N-acetylation, the reducing ends of the oligosaccharides were coupled with 2-aminopyridine and the pyridylamino (PA-) derivatives were purified by gel filtration and high performance liquid chromatography (HPLC) on an ODS-silica column. Three kinds of oligosaccharide fractions were separated by HPLC. The structure of each oligosaccharide isolated was analyzed by a combination of sugar component analysis, exoglycosidase digestion, another kind of HPLC using an amide-silica column, and 500-MHz 1H NMR spectroscopy. The structures of two main oligosaccharides were established to be: [Formula; see text] and [Formula; see text]. These two oligosaccharides were the first examples having xylose (or fucose) but no alpha-mannosyl linkage among the N-linked oligosaccharides of glycoproteins from both animal and plant origins.

Carbohydrate Sequence↗
PubMed1991

A study on the surface strain distribution on the hydroxyapatite-implanted canine tibia: a preliminary report.

It has been said by many investigators that hydroxyapatite ceramics may be prospective bone substitute materials. Its mechanical brittleness and strength has been the most serious consideration. In the present article a study has been done using animal experiments, the changes of surface strain at the hydroxyapatite implantation site of long-bone when the compressive stress is applied in the direction of long axis, in order to clarify the mechanical behaviors of hydroxyapatite living bone complex. The nonimplanted side was used as the control. Results revealed that the hydroxyapatite living bone complex has been proven to have sufficient flexibility such that it shows no hysteresis in stress versus strain relation up to 200 kg of applied load. The strain distribution pattern on the HA-implanted bone is quite similar to that of the nonimplanted one. This characteristic also suggests that it has normal skeletal function.

Animals↗
PubMed1991

[Vertebral bone density and its correlation with various factors related to bone metabolism in alcoholics: a quantitative study by computed tomography].

We measured vertebral bone density of 59 male alcoholics (ALC) using quantitative computed tomography (QCT). Bone density of ALC was decreased measured on admission compared with age-matched healthy male controls (ALC: 144 +/- 42, CONTROLS: 173 +/- 34 mg/cm3, p less than 0.05). The bone density was not correlated with serum ALP, Ca, and Pi. Serum parathyroid hormone and calcitonin were also not correlated with the bone density in ALC. Serum 25-(OH)-D showed significant positive correlation with the bone density (p less than 0.01) and 1,25-(OH)2-D showed trend of positive correlation with the bone density (p less than 0.01) in ALC. Severity of liver diseases did not have any relation to the bone density in ALC. Although the decreased bone density was not improved at the second QCT examined about 10 weeks after first QCT without medication, patients administered 1 microgram of 1 alpha-(OH)-D3 daily showed a significant increase in the bone density (on admission: 152 +/- 37, 10 weeks later: 162 +/- 35 mg/cm3, p less than 0.02). Combination therapy of 1 alpha-(OH)-D3 and calcitonin did not increase the bone density. These results indicate that bone density was decreased in ALC and a decrease in serum vitamin D metabolites may cause a decrease in the bone density, although liver dysfunction does not have a role in it. These data also suggest that 1 alpha-(OH)-D3 is effective in an increase in the bone density in ALC with osteoporosis after abstinence.

Adult↗
PubMed1991

[Problem drinkers among high school students in Japan].

In Japan, an increase in the consumption of alcohol by young people has been noted. This survey on drinking problems was performed on 1062 students of second year high school in 1990 using the Adolescent Alcohol Involvement Scale (AAIS). The results revealed that among all of the survey subjects of both sexes, 21.4% were abstainers, 4.2% normal adolescents, 60.9% non-problem drinkers, 12.6% alcohol misusers and 0.9% alcoholic-like drinkers. A high alcohol consumption rate and high percentages of those with drinking problems were observed among high school students. Students who used other addictive substances (i.e., smoking or thinner inhalation) reported significantly higher AAIS scores than those who didn't. Similarly high mean AAIS scores were found among students with family problems such as drinking parents or broken homes than those without this problem. Alcohol misusers and alcoholic-like drinkers accounted for 14.2% of males and 12.7% of females. In a survey performed 10 years previously on high school students, no alcoholic-like drinkers were found and only 1% were alcohol misusers. These results indicated that problem drinkers have dramatically increased among Japanese high school students in the last 10 years.

Adolescent↗
PubMed1991

[A study on the treatment duration of an antibacterial agent in complicated urinary tract infections. Utility and recurrence after 14-day treatment by fleroxacin].

In this study, fleroxacin (FLRX), a new quinolone derivative, was orally given at 300 mg once daily for 14 days to 102 patients with non-catheterized complicated urinary tract infections in order to determine the optimal treatment duration. We investigated its efficacy at day 5-7 and day 14, according to the criteria proposed by the Japanese UTI Committee, and also to the recurrence rate after the withdrawal. The results were as follows: 1. Overall clinical efficacy rates were 86% at day 5-7 and 84% at day 14. Both incidence of bacterial replacement in bacteriuria and normalization in pyuria were increased at day 14 as compared with those at day 5-7. 2. Bacteriological eradication rates were 91% at day 5-7 and 89% at day 14. 3. Clinical efficacy rates from physicians' evaluation were 86% at day 5-7 and 88% at day 14. 4. Incidence of side effects was 9.1%, and most of the cases were gastrointestinal symptoms which appeared within 4 days. Slight and transitory changes in laboratory findings were noted in 2.3% of evaluable cases. 5. With the occurrence of pyuria and bacteriuria as markers, the "no recurrence" rates were 63% at 1 week, 54% at 2 weeks, 61% at 3 weeks, 81% at 4-6 weeks after the withdrawal, and the "recurrence" rates were 4%, 4%, 6% and 5%, respectively. Remaining cases were judged as "reserved assessment". Generally, aggravation of bacteriuria was found but the aggravation of pyuria was observed in only few cases. 6. According to breakdown of cases with bacteriuria only, cure rate was 67% and recurrence rate was 33%. Re-infections were observed much more frequently than relapse based on the identification of infecting organisms. These results suggest that sufficient bacteriological eradication and clinical efficacy could be obtained by 14-day treatment of FLRX in non-catheterized complicated urinary tract infections. The efficacy of the treatment became evident around day 7. In approximately 30% of the cases in which eradication of the initial causative organisms was observed at day 14 reappearance of bacteriuria (greater than or equal to 10(3) CFU/ml) occurred after withdrawal of the antibiotic, but cases with pyuria were few, and the incidence of true recurrence was generally low. Onset of side effect after 5-day was not seen, hence FLRX seemed to be a safe agent.

Administration, Oral↗
PubMed1990

Cell surface molecule A5: a putative involvement in retinal central connection.

We produced monoclonal antibodies against Xenopus tadpole visual centers and obtained an antibody named A5 (MAb-A5). The antigen of MAb-A5 is a cell-surface-related protein molecule (A5 antigen). Immunohistochemistry using MAb-A5 and an eye-transplantation experiment suggest the involvement of A5 antigen in specific cell recognition between retinal axons and their targets.

Animals↗
PubMed1990

In vitro evaluation of the sealing ability of a calcium phosphate cement when used as a root canal sealer-filler.

A calcium phosphate cement (CPC) was examined for its ability to seal the root canal when used as a sealer-filler. Extracted human teeth were divided into three groups. Root canals were filled with either CPC paste containing dicalcium phosphate anhydrous (group 1), CPC containing dicalcium phosphate dihydrate (group 2), or gutta-percha points sealed with Grossman's cement (group 3). After filling, all specimens were kept in 100% humidity for 1 day, immersed in a CaPO4 solution or distilled water at 37 degrees C for 1 wk, and then immersed in 1% Poly-R dye solution at 37 degrees C for 1 wk, after which they were rinsed and sectioned longitudinally for microscopic examination. Specimens in groups 1 and 2, especially those aged in the CaPO4 solution showed considerably less dye penetration than those in group 3. The good sealing ability of the CPC against dye penetration in vitro suggests that it may provide an adequate seal of the canal without a separate sealer.

Calcium Phosphates↗
PubMed1990

Dietary treatment ameliorates overt diabetes and decreased insulin secretion to glucose, induced by overeating in impaired glucose tolerant mice.

Overt diabetes (NIDDM) was induced by overeating in neonatally streptozocin (60 mg/kg.BW) treated impaired glucose tolerant mice. We imposed a food restriction and a high fiber diet to evaluate the effects of dietary treatment in this NIDDM model mouse. Furthermore, insulin secretion after the dietary treatment was studied using the perfused pancreas technique. One group of IGT mice (SZ) was maintained on ordinary mouse chow during 6 to 14 weeks of age. The others received a cookie and chocolate mashed diet (C.C. diet) to induce overt diabetes during 6 to 10 weeks of age. Thereafter, the mice with induced overt diabetes were divided according to their diet treatment. The C.C. diet was continued in one group (SZC) for 4 weeks, and the others were divided into a food restriction group (SZR: 4 g/mouse/day of ordinary mouse chow, for 4 weeks) and a high fiber diet group (SZF: 20% W/W of cellulose in ordinary mouse chow, for 8 weeks). The mean caloric intake/mouse/day in SZC, SZR and SZF were 140, 80 and 98% of that in SZ, respectively. Amelioration of hyperglycemia and impaired glucose tolerance was noted in SZR and SZF. A better glycemic control was obtained in SZF with keeping a normal growth rate. On the pancreas perfusion, the insulin secretion to 30 mM glucose was improved in SZR and SZF. Furthermore, the incremental first phase peak insulin release to 30 mM glucose in SZF was significantly greater than that in SZC (SZF, 10.5 +/- 1.0 vs. SZC, 4.5 +/- 1.9 microU/min).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗