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Biomedical subjects

T Taguchi

Publications and source records attributed to T Taguchi.

At least 973 records · Page 54Linked to original sources
PubMed1980

Relationship of chemotherapy on human cancer xenografts in nude mice to clinical response in donor patient.

Responsiveness of experimental chemotherapy on human cancer xenografts in nude mice was directly compared with clinical response to the same chemotherapy in their donor patients. These xenografts were 1 line of rectal cancer (H-26), two lines of gastric cancer (H-08 and H-22), and 1 line of breast cancer (H-62). Experimental chemotherapies studied were single-drug FT-207 to four lines of xenografts and a combination of mitomycin C, 5-FU, and cytosine arabinoside (MFC) to a line of gastric cancer H-08. Single-drug treatment with FT-207 to H-26 resulted in remarkable retardation of the tumor growth. The comparative treatment with FT-207 suppository to the donor patient of H-26 showed appreciable response. All the other chemotherapies to three other lines (H-08, H-22, and H-62) induced no significant response, which was parallel to the corresponding clinical response in each donor patient. The sensitivity to chemotherapeutic drugs was thought to be still preserved in human cancer xenografts in nude mice.

Adult↗
PubMed1980

Review of a new antimetabolic agent 1-hexylcarbamoyl-5-fluorouracil (HCFU).

A new 5-fluorouracil (5-FU) derivative, 1-hexylcarbamoyl-5-fluorouracil (HCFU), has been developed in the National Cancer Center, and its phase I study is being performed in Japan by a clinical study group involving major institutions. Its LD 50 values are nearly equal to those of 1-(2-tetrahydrofuryl)-5-fluorouracil (FT-207) and greater than those of 5-FU, and this compound is more effective than the latter two analogues against various experimental murine tumor systems. In the phase I study, the incidence ratio of side effects was dose dependent, and the characteristic subjective symptoms were hot sensation and pollakisuria. No hematologic or serum biochemical changes were noted.

Aged↗
PubMed1980

Review of a new antimetabolic agent, 1,3-bis(tetrahydro-2-furanyl)-5-fluoro-2,4-pyrimidinedione (FD-1).

FD-1, a new anticancer drug, is a fluorinated pyrimidine derivative that has shown less acute toxicity than 5-FU and FT-207, and higher antitumor activity than FT-207 in Ehrlich carcinoma, S-180, AH-130, Yoshida sarcoma, and Walker 256. A principal feature of FD-1 is that, in comparison with FT-207, in oral administration it can maintain a higher concentration of 5-FU both in plasma and in tumor tissues. FD-1 is considered to be activated into 5-FU by a drug-metabolizing system in liver microsomes. In the plase I study of FD-1, the maximum tolerated dose was greater than 20 mg/kg in a single administration. The dose-limiting factor in FD-1 administration is gastrointestinal toxicity that causes side effects such as nausea and vomiting. The recommended dosage for daily oral administration of FD-1 is 6-12 mg/kg/day. In the phase I study of the sustained released form of FD-1 (FD-1-S), frequency of nausea and vomiting could be definitely reduced by the oral administration of FD-1-S, which showed higher tolerability. FD-1-S can be continuously administered at a dose ranging from 600 mg to 1200 mg/body/day for for 4 weeks and can be expected to have higher efficacy. In further studies on the long-term administration of FD-1-S, CNS toxicity has been reported in some cases.

Adult↗
PubMed1980

Retention organ distribution, and excretory pattern of cadmium orally administered in a single dose to two monkeys.

Retention, excretion, and organ distribution of radioactive Cd were observed after a single oral dose of two monkeys. The retention rate of Cd 19 d after the administration of radiocadmium (109CdCl2, carrier-free) to one monkey was 5.2% of the administered dose; 73.4% of the dose was excreted in the feces and 0.7% in the urine. The largest fractions of the administered dose were found in the small intestine, liver, and kidney. The absorption rate of Cd 25 d after the administration of radiocadmium with 1.0 mg cold Cd as CdCl2 solution to the othermonkey was 6.3% of the administered dose; 75.5% of the dose was excreted in the feces and 0.9% in the urine. Setting the whole body retention equal to 100% on d 19 or 25, the largest fractions were found in the small intestines (51.5 and 36.3%), livers (21.8 and 29.6%), and kidneys (13.4 and 21.0%) of the respective monkeys). The effect of carrier Cd on absorption, excretion, and organ distribution was not pronounced. The highest concentration and greatest retention of Cd was observed in the upper small intestinal wall and the content of the small intestine, indicating the importance of enteroenteric circulation of the element; this finding was different from the results for Cd metabolism in rodents.

Animals↗
PubMed1979

Biological activity of 24,24-difluoro-25-hydroxyvitamin D3. Effect of blocking of 24-hydroxylation on the functions of vitamin D.

To examine the question of whether 24-hydroxylation plays and importance role in the physiological functions of vitamin D, the biological activity of 24,24-difluoro-25-hydroxyvitamin D was compared with that of 25-hydroxyvitamin D in vitamin D-deficient rats. These two compounds were found almost identically active in the stimulation of intestinal calcium transport, the mobilization of calcium from bone, the healing of rachitic epiphyseal plate cartilage, the elevation of serum inorganic phosphorus, the mineralization of rachitic bone, and in the prevention of rachitogenesis in rats. Little or no difference was detected in the time course of response of intestinal calcium transport or bone calcium mobilization to the two forms of vitamin D. Therefore, in the rat no support could be obtained for the idea that 24,25-dihydroxyvitamin D3 plays an important role in the known physiological responses to the vitamin.

Animals↗
PubMed1979

Acute suppurative thyroiditis in children.

Ten cases of acute suppurative thyroiditis were studied. All patients remained euthyroid clinically during the course of this disease and during the follow-up. Of seven cases in which bacterial cultures were performed, an aerobic bacterium alone was isolated in one patient and anaerobic bacteria alone in four patients. Mixed aerobic and anaerobic microorganisms were recovered from one patient and cultures were negative in one case. Plasma TSH, T4, T3, and PBI levels were normal except in one case. The 131I uptake values were normal in six of seven cases. Plasma TSH response to TRH stimulation was normal in four of five cases. Antibodies against thyroglobulin and thyroid microsome were negative in four of six cases. These findings suggest that anaerobic bacteria may play an important role in the pathogenic process of acute suppurative thyroiditis and that the pituitary-thyroid functions are not impaired.

Bacterial Infections↗
PubMed1979

Kinetic analysis of plasma TSH dynamics after TRH stimulation.

Kinetic analysis of the time course of plasma TSH after TRH stimulation was performed by means of a single compartment model with first order input. This kinetic model showed satisfactory fit to the data, and was found to be useful enough for the characterization of plasma TSH dynamics. In endocrinologically normal short children, the amount of TSH release per unit volume of distribution space (Q0/V), the rate constant for the TSH release (alpha), and the rate constant for TSH elimination (beta) were averaged 23.4 microU/ml, 6.981 hr-1 and 0.813 hr-1, respectively. Elevated Q0/V values with lowered alpha and beta were obtained in the hypothyroid children. Variable results, with the exception of low alpha values, were obtained in the children with pituitary dwarfism.

Adolescent↗
PubMed1979

Vitamin D sclerosis in rats.

The early fine structural changes in the arteries of rats induced by excess vitamin D3 perorally or parenterally were essentially similar, except the latter had a more prominent toxic effect to the vascular wall. The ultrastructural features, incidental to calcification, included the appearance of increased ground substance with a separation of collagenous and elastic fibrils, and degenerative changes in smooth muscle cells. Atherosclerosis was greatly accelerated at the sites of vascular injury when cholesterol, cholic acid and thiouracil were added to the basal diet. Calcification was initially observed in relation to elastic fibrils or degenerated cells in the upper and middle layers of the arteries, although there were few such deposits in the thickened intima of the coronary arteries. Calcium deposition could not be a direct effect of hypercalcemia, but the functional activity of smooth muscle cells did seem to promote the mineralization of calcium and phosphate. Furthermore, vitamin D-induced sclerosis did not prevent intimal thickening of the arteries when vitamin D3 was withdrawn.

Animals↗
PubMed1979

Effects of dietary cadmium on rhesus monkeys.

Ten male rhesus monkeys, each weighing 3.5 kg, were divided into four groups of 3, 3, 2, and 2, and were fed daily with 100 g pelleted food containing 300, 30, 3, and 0 ppm cadmium, respectively. Urine samples were collected every 2 weeks and blood samples every 4 weeks. One monkey each of the 300 and 30 ppm groups was autopsied for pathological examination and tissue cadmium determination at the week 24 of the experiment; the remaining 8 animals were killed after 55 weeks. The lowest exposed group (3 ppm) did not show any specific biological response to cadmium over a period of 55 weeks. In the 30 ppm group, no significant changes were observed for up to 24 weeks, although cadmium concentration in the renal cortex and urine at 24 weeks were 300 mug/g wet weight and 18 mug/l., respectively. Plasma urea nitrogen and urine protein (quantitative determination) increased after 30 and 36 weeks. At 55 weeks of the experiment, qualitative tests were negative for low molecular weight proteinuria and glycosuria, and the results remained normal for renal and liver function tests and blood analysis, although cadmium concentrations in the renal cortex of two monkeys were 460 and 730 mug/g wet weight and those in the liver were 110 and 160 mug/g wet weight, respectively. In the highest exposure group (300 ppm), urine cadmium increased to 250 mug/l. by 11 weeks, and urine retinol-binding protein, plasma GOT, GPT, and LDH increased after 12 weeks. Proteinuria (quantitative determination), glycosuria, aminoaciduria (panaminoaciduria), and erythrocytopenia were observed after 16 weeks, when urine cadmium was 500-900 mug/l. Hypohemoglobinopathy and proteinuria (qualitative determination) were observed after 20 and 24 weeks, while cadmium concentrations in the renal cortex and the liver were 760 and 430 mug/g wet weight at 24 weeks, respectively. Slightly depressed tubular reabsorption of phosphate, increased urine beta(2)-microglobulin, increased plasma urea nitrogen, and increased plasma alpha(2)-globulin fraction (electrophoresis) were observed between 28 and 30 weeks of the experiment. Creatinine clearance and plasma cholinesterase decreased after 47 and 54 weeks, respectively. Cadmium concentrations in the renal cortex and the liver of two monkeys at 55 weeks were 350 and 580 mug/g wet weight and 410 and 630 mug/g wet weight, respectively. Pathological examinations revealed denaturation, destruction, and regeneration of the epithelial cells in renal proximal tubules, but no pathological changes in osseous tissues. Critical cadmium concentration in the renal cortex was estimated to be 380 mug/g wet weight for low molecular weight proteinuria and 470 mug/g wet weight for proteinuria, glycosuria, and aminoaciduria. Critical concentration in the liver was also estimated to be 210 mug/g wet weight. The apparent biological half-time of cadmium in monkeys at autopsied stage was calculated to be 0.66, 6.4, 5.2, and 22.4 years for the 300, 30, 3, and 0 ppm groups, respectively.

Animals↗