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Biomedical subjects

T Nishida

Publications and source records attributed to T Nishida.

At least 235 records · Page 13Linked to original sources
PubMed1998

In vivo determination of the direction of rotation and moment-angle relationship of individual elbow muscles.

The direction of rotation (DOR) of individual elbow muscles, defined as the direction in which a muscle rotates the forearm relative to the upper arm in three-dimensional space, was studied in vivo as a function of elbow flexion and forearm rotation. Electrical stimulation was used to activate an individual muscle selectively, and the resultant flexion-extension, supination-pronation, and varus-valgus moments were used to determine the DOR. Furthermore, multi-axis moment-angle relationships of individual muscles were determined by stimulating the muscle at a constant submaximal level across different joint positions, which was assumed to result in a constant level of muscle activation. The muscles generate significant moments about axes other than flexion-extension, which is potentially important for actively controlling joint movement and maintaining stability about all axes. Both the muscle DOR and the multi axis moments vary with the joint position systematically. Variations of the DOR and moment-angle relationship across muscle twitches of different amplitudes in a subject were small, while there were considerable variations between subjects.

Biomechanical Phenomena↗
PubMed1998

Purification and characterization of a nylon-degrading enzyme.

A nylon-degrading enzyme found in the extracellular medium of a ligninolytic culture of the white rot fungus strain IZU-154 was purified by ion-exchange chromatography, gel filtration chromatography, and hydrophobic chromatography. The characteristics of the purified protein (i.e., molecular weight, absorption spectrum, and requirements for 2,6-dimethoxyphenol oxidation) were identical to those of manganese peroxidase, which was previously characterized as a key enzyme in the ligninolytic systems of many white rot fungi, and this result led us to conclude that nylon degradation is catalyzed by manganese peroxidase. However, the reaction mechanism for nylon degradation differed significantly from the reaction mechanism reported for manganese peroxidase. The nylon-degrading activity did not depend on exogenous H2O2 but nevertheless was inhibited by catalase, and superoxide dismutase inhibited the nylon-degrading activity strongly. These features are identical to those of the peroxidase-oxidase reaction catalyzed by horseradish peroxidase. In addition, alpha-hydroxy acids which are known to accelerate the manganese peroxidase reaction inhibited the nylon-degrading activity strongly. Degradation of nylon-6 fiber was also investigated. Drastic and regular erosion in the nylon surface was observed, suggesting that nylon is degraded to soluble oligomers and that nylon is degraded selectively.

Amidohydrolases↗
PubMed1998

Recovery of blood flow and oxygen transport after temporary ischemia of rat liver.

Hepatic tissue perfusion and O2 supply after ischemia are indispensable for recovery of cellular functions, but few studies have been performed regarding the recovery of tissue blood flow and O2 transport. After 5, 15, and 30 min of ischemia of rat livers, hepatic tissue perfusion, hepatic arterial and portal blood flow, plasma PO2, and O2 transport parameters were measured. Hepatic tissue blood flow and erythrocyte velocity in the sinusoids showed biphasic recoveries after temporal ischemia for 5, 15, and 30 min. The first peak in the flow appeared at 3-4 min after the initiation of tissue perfusion, and the second peak appeared at approximately 20 min, irrespective of the ischemic period. Hepatic blood flow during the initial increase contained relatively low O2-saturated blood compared with that in the second increase. Livers that had been subjected to a prior hepatic artery ligation only showed the first peak at approximately 4 min. The first increase in hepatic blood flow corresponded to the peak in the portal venous flow, and the second increase corresponded to that of the hepatic artery. These results suggested that hepatic microcirculation after temporary hepatic ischemia showed biphasic recoveries because of different restoration patterns of the portal vein and hepatic artery.

Animals↗
PubMed1998

Enhanced miotic response to topical dilute pilocarpine in patients with Alzheimer's disease.

To determine whether miotic response to dilute (0.0625%, two drops) topical pilocarpine could be useful in detecting Alzheimer's disease (AD), we assessed the response in 14 AD patients and 10 control subjects. The miotic response to pilocarpine was significantly greater in AD patients than in control subjects (p < 0.001). In contrast, mydriatic response to the anticholinergic tropicamide (0.01%, one drop) failed to show a difference between the groups (p = 0.54). There was no significant correlation between the miotic and mydriatic responses in individuals. We conclude that dilute pilocarpine could be useful as a diagnostic tool in early AD.

Administration, Topical↗
PubMed1998

Basic studies on N''-ursodeoxycholyldiethylenetriamine-N,N,N'-triacetic acid for the dissolution of calcified gallstones.

A novel calcium-chelating agent, N"-ursodeoxycholyldiethylenetriamine-N,N,N'-triacetic acid (UDCA-DTTA), was synthesized to study its ability to dissolve calcified gallstones. The chelating activity of the compound was demonstrated by dissolving calcium carbonate in vitro at a high dissolution rate. In the presence of the agent, sliced human gallstone with a composition of more than 50% calcium bilirubinate was thoroughly dissolved, indicating that calcium bilirubinate was dissolved from the gallstone. The ability to dissolve calcium was comparable to that of EDTA. However, the laminar structure of the sliced gallstone did not disappear in the presence of EDTA, whereas the structure disappeared in the presence of UDCA-DTTA. All these results indicate that UDCA-DTTA is an interesting compound as a parent substance for developing a prodrug for an oral or intravenous agent to dissolve calcium-containing gallstones.

Administration, Oral↗
PubMed1998

An osteometrical study of the cranium and mandible of the lesser mouse deer (Chevrotain), Tragulus javanicus.

The lesser mouse deer (Tragulus javanicus) is one of the most primitive ruminants. Skulls of lesser mouse deer were measured to evaluate their growth. The age was estimated from the eruption and attrition of molars on the mandible. A total of 95 specimens was divided into five age groups, and the growth pattern in each sex was established for some measurements. The relative growth coefficients were calculated for the head and body length and several parts of the cranium and mandible against the profile length. Sexual dimorphism could not be found on the skull in any age group except for measurements related to the upper canine. However, females showed a higher value in head and body length in the oldest group. This feature was consistent with an interpretation of mouse deer society as monogamous. Growth was more rapid in length than in width. Various statistical analyses showed that the visceral cranium related to masticatory facility was much better developed than the neurocranium. However, observations on the shape of the mandible ramus and of the premolars implied that the masticatory function was not suitable for taking roughage. This speculation agreed with previous reports on the feeding habits and digestive organs of the mouse deer.

Age Determination by Teeth↗
PubMed1998

Monoclonal antibody TSd-1 is specific to elongating and matured spermatids in testis of common tree shrew (Tupaia glis).

The monoclonal antibody (MAb), named TSd-1, specific to spermatogenic cells of the common tree shrew (Tupaia glis) was established and characterized using immunohistochemistry and immunoblotting. MAb TSd-1 reacted with elongating and matured spermatids in a stage-dependent manner. TSd-1 recognized a 94 kilodalton (kDa) peptide in the plasma membrane and cytosol. Additionally, an extremely weak 107 kDa band was detected only in the cytosol. The reactions were not detected in round spermatids. In elongating Stage VI spermatids, the plasma membrane and the granular structure within the cytoplasm were intensely positive, and most intense after the appearance of new round spermatids in the lower layer (Stage I). The reactions were observed neither in the other organs of the common tree shrew nor in the testes of other animals, indicating that TSd-1 antigen is specific to the spermatogenic cells of the common tree shrew, and may act on elongating or matured spermatids.

Animals↗
PubMed1998

Comparison of osseointegration between hydroxyapatite-coated and uncoated threaded titanium dental implants placed into surgically-created bone defect in rabbit tibia.

The purpose of this study was to compare the degree of osseointegration between hydroxyapatite (HA)-coated and uncoated threaded titanium dental implants placed into a surgically created bone defect with or without an expanded polytetrafluorethylene (ePTFE) membrane. A conventional implant site was prepared and either a HA-coated or an uncoated implant was placed in each tibia of 12 rabbits (conventional group). A bone defect approximately 3 mm in width was created on the distal end of the conventional site and either a HA-coated or an uncoated implant was placed there (bone defect group). For another group, the same procedure was performed as in the bone defect group, except the implant sites were covered with ePTFE membranes (ePTFE group). After 4 months, the rabbits were sacrificed. Specimens were prepared and examined histometrically. The results demonstrated that HA-coated threaded titanium dental implants consistently showed a greater amount of osseointegrated surface either in the conventional site or defect region with and without ePTFE membranes in this animal model. In conclusion, a HA-coated threaded titanium implant may be the choice of dental implants to establish greater osseointegration with the defect or conventional site.

Animals↗
PubMed1998

Effect of troglitazone on microalbuminuria in patients with incipient diabetic nephropathy.

OBJECTIVE: Although some studies have suggested a direct action of troglitazone on vascular cells, its effects on diabetic vascular diseases have not been reported. We therefore investigated the effect of troglitazone on microalbuminuria in patients with incipient diabetic nephropathy. RESEARCH DESIGN AND METHODS: A total of 30 patients with type 2 diabetes associated with microalbuminuria (urinary albumin-to-creatinine ratio [ACR] [milligrams per gram creatinine] ranging from 30 to 300 mg/g creatinine) were studied. They were randomly divided into two groups: patients treated with metformin (500 mg/day, n = 13) or with troglitazone (400 mg/day, n = 17) for 12 weeks. ACR, lipid profile, blood pressure, glycated hemoglobin, and plasma glucose during meal-load tests were measured every 4 weeks. RESULTS: Anthropometric indices (BMI and percent fat), lipid profile, and blood pressure did not change with either treatment. Fasting and postmeal glucose levels decreased similarly in the two groups. Decrements in glycated hemoglobin were greater in the metformin group at 4 and 8 weeks after the initiation of treatment (P < 0.05). Troglitazone reduced ACR (median [25-75th percentiles]) from 70 (49-195) to 40 (31-90) mg/g creatinine at 4 weeks (P = 0.021) and maintained these reduced levels throughout the treatment period (8 weeks: 35 [26-68], P = 0.007; 12 weeks: 43 [26-103], P = 0.047). Metformin did not change ACR throughout the 12 weeks. CONCLUSIONS: Troglitazone ameliorated microalbuminuria in diabetic nephropathy. Furthermore, our findings suggest that troglitazone has some effects on vascular cells other than lowering plasma glucose levels. Troglitazone might be useful for diabetic angiopathy, including nephropathy and coronary artery disease.

Aged↗
PubMed1998

A metastasis to the nasal tip from a cervical carcinoma--a case report.

Metastases to the nasal tip from gynecological malignancies are extremely rare. We present a case of a tumor metastatic to the nasal tip from a carcinoma of the uterine cervix. We administered high-dose focal irradiation to the site of the tumor. The literature on metastases to the nose, maxillary sinuses, and paranasal sinuses from gynecologic malignancies is reviewed.

Aged↗
PubMed1998

Suppression of heat-induced p53 accumulation and activation by CDDP or x-rays in human glioblastoma cells.

We showed that the prominent suppressions of heat-induced accumulation and activation of p53 by CDDP or X-rays were observed in A-172 cells, but not in T98G cells. In addition, the interactive hyperthermic enhancement of CDDP or X-ray cytotoxicity was observed in A-172 cells, but not in T98G cells. Our findings indicate that suppressions of heat-induced accumulation and activation of p53 by CDDP or X-rays contribute positively to an interactive hyperthermic enhancement of CDDP- or X-ray cytotoxicity.

Antineoplastic Agents↗
PubMed1998

[Application of monoclonal antibody for drug delivery system--missile therapy for cancer].

Clinical applications of monoclonal antibody for selective delivery of anticancer drug, toxin and radioisotope were reviewed. The difficulties in preparation and clinical application of chemoimmunoconjugate were pointed out. Also the difficulties of immunotoxin in clinical trial due to its high toxicity had been discussed and it is assumed that development of blocked ricin may overcome many problems related to toxicities. Clinically most advanced immunoconjugate seems to be radioimmunoconjugate. Among three types of immunoconjugates preparation of radioimmunoconjugate is easiest and some promising clinical trials were introduced in this review.

Animals↗
PubMed1998

[Successful treatment of pseudomyxoma peritonei using combination chemotherapy of intraperitoneal low-dose CDDP and oral 5'-DFUR administration].

We report a case of pseudomyxoma peritonei treated with combination chemotherapy. A 73-year-old woman was diagnosed as having psuedomyxoma peritonei originated from the vermiform appendix. Appendectomy was performed, and 10 mg of MMC was administered intraperitoneally. From day 7, 600 mg/day of 5'-DFUR was orally given for 2 years, and 20 mg of CDDP once a month was intraperitoneally administered seven times. The patient has been doing well with no evidence of tumor recurrence for two years after operation. Combination chemotherapy with CDDP and 5'-DFUR, as a biochemical modulation therapy, has fewer side effects and leads to better quality of life of patients. We recommend a combination chemotherapy with low-dose CDDP and 5'-DFUR for patients in poor general condition.

Administration, Oral↗
PubMed1998

[Characterization and problems regarding clinical reference ranges of aged subjects on clinical chemistry].

Various characteristic clinical laboratory testing data related to clinical chemistry were collected from 11 institutes across the nation, and age-related clinical reference values, reference intervals and within-subject biological variations were calculated. Using these calculated results, characterization of aged-related reference ranges and the method of determining an aged subject's testing values were investigated. From these results, the following facts became clear. Estimation of health-associated reference intervals for aged subjects was very difficult. As the aged subject's reference values differ remarkably by sex and age on several test items, sex- and age-related clinical reference values are necessary. In case of the mass screening survey which utilizes preceding healthy values, we should decide by within-subject biological variation. We usually use reference ranges to decide whether the measured values are located within these ranges, and must use a differential value to speculate regarding a particular disease. These results indicate that multiple standard must be prepared for each clinical laboratory testing value, and that it is ideal to be able to select a suitable standard for the subjects state. To select a suitable standard clinically, we need an expert system. For this purpose, much more basic data concerning reference ranges, differential values and so on must be accumulated.

Aged↗
PubMed1998

[FK506 for the prophylaxis of graft-versus-host-disease after bone marrow transplantation from HLA-genotypically mismatched unrelated donor].

Eleven leukemia patients who had undergone bone marrow transplants from HLA-A, B, DR genotypically mismatched unrelated donors received FK506 and short-term methotrexate as prophylaxis for graft-versus-host disease (GVHD). Grade III-IV acute GVHD developed in 2 of the patients, and chronic GVHD developed in 4 of the other patients. Adverse drug reaction included reversible nephrotoxicity, hyperglycemia (all patients) and hypertension (9 patients). Hyperglycemia and hypertension of grade 3 or higher occurred mostly in the patients who were on supplemental steroids. However, severe nephrotoxicity was not observed. Complications included cystitis (4 patients), cytomegalovirus colitis (3 patients), Interstitial Pneumonitis (IP) (3 patients), tuberculosis (1 patient), and thrombotic microangiopathy (1 patient). None of patients relapsed. Although close monitoring of FK506 blood concentration and patient clinical signs are required, we concluded that FK506 is effective for GVHD prophylaxis after bone marrow transplantation from HLA-A, B, DR genotypically mismatched unrelated donors, and that adverse reactions due to FK506 are controllable. To determine the long-term effectiveness of this drug, it will be necessary to conduct prospective randomized studies that compare it wiht cycloporin A as a preventive treatment against GVHD in patients who receive bone marrow transplants from HLA genotypically mismatched unrelated donors.

Adolescent↗
PubMed1998

Examination of prognostic factors after resection of pulmonary metastasis of osteosarcoma by multivariate analysis.

Prognostic factors for the case of pulmonary metastasis of osteosarcoma was examined using the multivariate analysis. 1) The 3-year survival rate after operation of primary focus in 23 cases was 34.8% and the 5-year survival rate was 30.4%. The 3-year survival rate after the first operation of pulmonary metastasis was 30.4% and the 5-year survival rate was 12.2%. No deaths attributed to operation were found. 2) Gender, age, histological type, solitary or multiple pulmonary metastasis, laterality, number of pulmonary metastatic tumors, TDT and DFI were examined, and the laterality, number of pulmonary metastatic tumors and DFI were considered to be useful prognostic factors. DFI among them was most closely associated with postoperative survival days. 3) A significant difference in the number of excised nodules was found between the DFI less than 90 days group and the DFI not less than 90 days group, and the number in the former group was significantly larger. 4) It was suggested that postoperative observation and close examination for pulmonary metastasis at about 3 months intervals after of primary focus are important, and also, positive or negative pulmonary metastasis as the time of examination, particularly, the number metastatic nodules of less than 5 or not less than 5, are reflected in the prognosis. 5) Expected survival time after the first operation pulmonary metastasis appeared possible to estimate as 3.0 x DFI days.

Adolescent↗