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Biomedical subjects

T Takemoto

Publications and source records attributed to T Takemoto.

At least 19 recordsLinked to original sources
PubMed1992

Conformational feature of neuroactive domoic acid: X-ray structural comparison with isodomoic acid A and alpha-kainic acid.

As an aid for developing a new type of potent insecticide acting on the neuromuscular junction, conformational characteristics of domoic acid and isodomoic acid A, the naturally occurring glutamate agonists, were investigated by X-ray crystal analyses. Conformational comparison with a neuroactive alpha-kainic acid provides information concerning the stereochemical feature responsible for the biological activity.

Insecticides↗
PubMed1992

Application of ultrasonic probes prior to endoscopic resection of early gastric cancer.

The development of a new strip biopsy technique for endoscopic mucosectomy utilizing endoscopic saline injection and a double-channel endoscope permits the safe and simple resection of superficial type early gastric cancer which has been difficult to perform with conventional polypectomy techniques. Preresection assessment of the depth of invasion and postresection assessment of efficacy are important with regard to treatment of early gastric cancer, but conventional endoscopic ultrasonography employed for this purpose requires special equipment and involves intricate procedures. An ultrasonic probe which can be used endoscopically has recently been developed and is currently in the trial stage. The authors have conducted studies with respect to a 7.5 MHz radial scanning type Miniature Ultrasonic Probe as well as a 20 MHz manual linear scanning type Sonoprobe System. Experimental studies indicated that the former type is capable of delineating postresection ulcers, while the latter permitted delineation of tumors as hypoechoic images in 9 of 11 cases of early gastric cancer.

Adenocarcinoma↗
PubMed1992

Ecological structure and incidence rates of schizophrenia in Nagasaki City.

The purpose of this study was to investigate the relationship between incidence rates of schizophrenia and residential features in Nagasaki City, Japan. Social features of residents in 259 areas in the Nagasaki City ecological structure were determined using the results of the 1980 national census. Six residential factors--employment status, occupational and academic career, household status, length of residence, housing tenure and young male predominance--were selected as factors that clearly reflect residential differentiation of residents. Contrary to the findings of many other studies conducted in Western cities, no statistically significant differences were observed, although it seemed that incidence rates were comparatively higher in the lower social classes. These results possibly reflect differences in cultural and social values and structures.

Adult↗
PubMed1992

[Endoscopic treatment of early colorectal cancer].

Early cancer of the colon and rectum is currently treated by endoscopic or surgical resection. We studied the indications for endoscopic treatment of early colorectal cancers (80 lesions) in relation to the size and macroscopic findings. The endoscopic treatment consists of polypectomy for a pedunculated or a sessile polyp and strip biopsy for a plaque-like or a depressive lesion. Microscopic or most small cancers were completely treated endoscopically. From macroscopic findings of the early cancers, type Ip (less than 2cm and 2cm in diameter) was completely treated by polypectomy, type I s and type II a (less than 1cm and 1cm in diameter) by polypectomy or strip biopsy, and type II c (less than 0.5cm and 0.5cm in diameter) by strip biopsy.

Colonic Neoplasms↗
PubMed1991

Effects of various mucosal protective drugs on diethyldithiocarbamate-induced antral ulcer in rats.

This study was designed to determine the effects of exogenous Cu,Zn-superoxide dismutase (SOD) and various mucosal protective agents against antral ulcer induced by diethyldithiocarbamate (DDC), inhibitor of Cu,Zn-SOD. Exogenous Cu,Zn-SOD reduced ulcer formation and prevented a decrease in SOD activity in gastric mucosa. This result indicates that maintenance of mucosal SOD activity is essential to prevent the ulcerogenicity of DDC. Many mucosal protective drugs that increase blood flow, mucus secretion, and endogenous prostaglandin failed to prevent ulcer formation and decrease of mucosal SOD activity. Rebamipide, however, significantly reduced ulcerogenesis and maintained mucosal SOD activity. This suggests that rebamipide has new protective effects on gastric mucosa.

Alanine↗
PubMed1991

Role of epidermal growth factor in protection and repair of gastric mucosal injury.

A role of epidermal growth factor (EGF) in protection and repair of gastric mucosal injury caused by p.o. administration of 0.6 N HCl was investigated in male Wistar rats. Previous to the study on the role of EGF in gastric mucosal protection and repair, changes of gastric mucosal EGF level was determined sequentially by RIA for 180 min after treatment with 0.6 N HCl and intraperitoneal injection of recombinant hEGF. Concentration of incorporated hEGF into the gastric mucosa reached the peak level at 30 min after injection of hEGF. On the other hand, the gastric endogenous EGF level fell remarkably immediately after treatment with 0.6 N HCl. Successively, an association with the mucosal levels of incorporated hEGF and gastric ulcer indices was investigated in the rats in which hEGF was injected intraperitoneally 30 min prior to or at the same time as oral administration of 0.6 N HCl. In conclusion, pretreatment with hEGF protected significantly against gastric mucosal injury with 0.6 N HCl, whereas simultaneous administration of hEGF could not protect against mucosal injury but indicated possible stimulation of the repair process from acute gastric mucosal damage.

Animals↗
PubMed1991

Evaluation of peptic ulcer healing with a highly magnifying endoscope: potential prognostic and therapeutic implications.

Gastric and duodenal ulcer healing and scarring were evaluated with a highly magnifying endoscope. The appearance of scar was classified into three types: Sa, with a depression at the center; Sb, with a pattern of regenerated mucosa reaching the center; and Sc, with a uniform pattern throughout. The relationship between regenerative mucosal patterns and histologic findings of biopsy specimens was investigated in 58 patients with gastric ulcer. Mucosal regeneration was sufficient in 26.7% of patients with Sa pattern, 79.2% of patients with Sb pattern, and 100% with Sc pattern. From prospective endoscopic follow-up observations, the relationship between endoscopic findings of ulcer scars and ulcer relapses was investigated in 80 patients with gastric ulcer and 56 patients with duodenal ulcer. As a result, patients who completed the cycle of ulcer healing from Sa pattern through Sb to Sc patterns had rarely relapse. In contrast, patients with a Sa pattern of mucosal scar showed a high rate of recurrence: 88.8% for gastric ulcer, and 88.0% for duodenal ulcer. Our method of evaluation of gastric and duodenal ulcer healing with a highly magnifying endoscope may have important prognostic and therapeutic implications. It may indicate a population of patients (with Sa scarring pattern) with a high risk of ulcer recurrence and therefore requiring prolonged prophylactic treatment.

Cicatrix↗
PubMed1991

Caroli's disease: scintigraphic and radiographic findings.

Caroli's disease is a rare congenital anomaly of the liver. Since new diagnostic techniques for the evaluation of hepatic disease have been introduced, the number of reported cases of Caroli's disease has been gradually increasing. This report describes the case of a 13 year old girl with nausea, vomiting, fever and hepatomegaly. The diagnosis of Caroli's disease was established by ultrasonography and CT scan. The complications and management are discussed. The important points in management are to relieve symptoms and to conduct regular examinations by ultrasonography for the early detection of hepatobiliary carcinoma.

Adolescent↗
PubMed1991

Physical growth of Aymara children in a herding community of the Bolivian Altiplano.

In a small agropastoral Aymara community called Wariscata in the Andean Altiplano of Bolivia, anthropometric measurements were made in 1988. In comparison with those of published data for the other rural and urban Andean populations (Aymara, Quechua and Mestizo at high and low altitudes), the Aymara children of Wariscata were taller and heavier than other rural high altitude native children, but similar in height to urban high altitude children. This is possibly due to secular change of growth accompanied with nutritional improvement that has taken place in recent years. Chest width and depth had similar values to those in other Aymara children. But, Aymara children in Wariscata of both sexes had smaller chest dimensions (depth and width) than those of Quechua children. However, these ethnic differences in chest dimensions were not reflected in the adult Aymara and Quechua, suggesting different process of chest growth in Aymara and Quechua populations.

Adolescent↗
PubMed1990

Role of active oxygen species in diethyldithiocarbamate-induced gastric ulcer in the rat.

Diethyldithiocarbamate, an inhibitor of Cu,Zn-superoxide dismutase, was recently found to be ulcerogenic in the rat stomach, and active oxygen species were found to be responsible for its ulcerogenicity. To clarify which active oxygen species play a role in ulcerogenesis, the effects of various scavengers and iron-chelators were studied. As superoxide dismutase and catalase reduced the ulcerogenesis induced by diethyldithiocarbamate, the superoxide radical and hydrogen peroxide were considered to play a pathogenic role in this ulcer model.

Animals↗
PubMed1990

Lack of tumorigenicity of aminopyrine orally administered to B6C3F1 mice.

To test the tumorigenic potential of aminopyrine, an antipyretic analgesic, it was administered in drinking water at levels of 0 (control), 0.04 and 0.08% to 50 male and 50 female B6C3F1 mice for 100 weeks, and the mice were subsequently maintained without aminopyrine for a further 4 weeks. The most frequent types of tumor, in both treated and control groups, were hepatocellular tumor in male mice and malignant lymphoma/lymphoid leukemia in female mice. No statistically significant differences were observed in the incidences of these tumors between treated and control groups. The incidences of several other tumors in male and female mice also showed no statistically significant differences between treated and control groups. Therefore, no tumorigenic effect of orally administered aminopyrine in B6C3F1 mice was apparent in the present study.

Administration, Oral↗
PubMed1990

An immunohistochemical study of copper, zinc-containing superoxide dismutase detected by a monoclonal antibody gastric mucosa and gastric cancer.

The immunohistochemical localization of copper, zinc-superoxide dismutase (Cu,Zn-SOD) in human gastric mucosa and gastric cancer was studied using a monoclonal antibody. In gastric mucosa, parietal cells, pyloric glandular cells and foci of intestinal metaplasia showed positive staining in the cytoplasm and/or nucleus. The wide distribution of Cu, Zn-SOD in the gastric mucosa suggests cell function may be vulnerable to active oxygen species. In gastric cancer, 34 of 70 cases showed a positive reaction for Cu, Zn-SOD. There was a relationship between the grade of Cu,Zn-SOD immunoreactivity and the histological type of gastric cancer, well-differentiated types of gastric cancer being more frequently positive. The positive cases of poorly-differentiated adenocarcinoma were characterized by a pattern of diffusely infiltrative invasion. These results suggest that some types of gastric cancer are resistant to active oxygen species.

Adenocarcinoma↗
PubMed1990

Binding specificity of Fusobacterium nucleatum to human erythrocytes, polymorphonuclear leukocytes, fibroblasts, and HeLa cells.

Eighteen strains of Fusobacterium nucleatum were studied with respect to their adherence to human erythrocytes, polymorphonuclear leukocytes, fibroblasts, and HeLa cells. Four types of adherence were found: 1) sugar-sensitive adherence 2) amino acid-sensitive adherence 3) unknown adherence 4) weak adherence. There was no obvious correlation between the patterns of hemagglutination and adherence to other cells. The results indicate not only a complex network of bacterial receptors on human cells, but also a variety of types of bacterial adherence as expressed by the selectivity of the bacterial binding to specific cell surfaces.

Acetylgalactosamine↗