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Biomedical subjects

H Takagi

Publications and source records attributed to H Takagi.

At least 541 records · Page 30Linked to original sources
PubMed1995

Heterotransplantation of human parathyroid glands into nude mice.

Heterotransplantation of human parathyroid tissues into nude mice was performed to investigate the characteristics of grafted tissues. Grafts prepared from hyperplasia, adenoma and normal glands which were resected at operation were implanted in the gluteus muscle of the recipient mice (female, KSNnu/nu strain). Graft function was evaluated by measuring human intact PTH concentrations in sera of the mice. Serum PTH concentrations 12 weeks after transplantation were correlated with the tissue volume in the mice which received one, two, four or eight pieces of 1 mm3 hyperplastic tissues. Changes in graft function were examined in the mice which received four grafts prepared from hyperplasia, adenoma or normal glands. Transplantation of parathyroid tissues resulted in an increase in PTH concentrations for 4 weeks, reaching a plateau thereafter. The level remained unchanged for 8 weeks. Serum PTH levels in the mice with grafts prepared from hyperplasia or adenoma were significantly higher than in those with grafts from normal glands, though without a significant difference between the mice with grafts from adenoma and from hyperplasia. Serum calcium levels were similar in all three groups. We also observed the response of grafted parathyroid tissue to a low calcium level in sera: there was higher PTH secretion four weeks after the administration of the low calcium diet. The success of heterotransplantation was histologically proven by the presence of grafts which were not atrophic in the muscle 12 weeks after transplantation. Nucleoli were found more frequently, and nuclear pleomorphism was observed in the cells of heterografts.

Adenoma↗
PubMed1995

Type II citrullinemia associated with neutropenia.

A 37-year-old Japanese man was admitted with delirium and hyperammonemia. He was diagnosed as having type II citrullinemia because of an elevated citrulline level on amino acid analysis and very low hepatic argininosuccinate synthetase activity. He also showed a low neutrophil count and a low serum level of granulocyte colony-stimulating factor. Reduced production of this cytokine and/or impairment of its feedback regulation by the neutrophil count may have played a role in the neutropenia of this patient.

Adult↗
PubMed1995

Comparative analysis of vascular endothelial growth factor receptors on retinal and aortic vascular endothelial cells.

Ischemic eye disease often results in ocular neovascularization, presumably due to the elaboration of growth factors. Diabetic retinopathy is a classic example in which dramatic retinal neovascularization arises after ischemic retinal damage. The characterization of vascular endothelial growth factor (VEGF) as an angiogenic molecule whose expression is markedly induced by hypoxia makes it a promising candidate for mediating ischemic retinal neovascularization. Thus, we have characterized the structure, binding, and regulation of VEGF receptors in bovine retinal (BREC) and aortic endothelial cells (BAEC). VEGF stimulated a 2.1-fold increase in BREC number and DNA content at 0.6 nmol/l VEGF (P < 1 x 10(-7)). Scatchard binding analysis demonstrated specific high-affinity VEGF receptors on BREC with a Kd of 4.9 +/- 0.6 x 10(-11) mmol/l, similar to that observed for BAEC at 5.1 +/- 0.4 x 10(-11) mmol/l. BREC, however, possess 1.5 x 10(5) high-affinity receptors/cell, threefold more than BAEC (P < 0.003) and more than any cell type reported previously. 125I-VEGF affinity cross-linking revealed complexes at 220 and 170 kDa in BREC, but only a 220-kDa band of lesser intensity in BAEC. Cross-linking was displaceable in a dose-dependent manner by VEGF (P < 0.01) but not by other hormones. Hypoxia increased VEGF receptor number 50% in BREC without altering affinity. Antiphosphotyrosine immunoblotting showed VEGF-stimulated tyrosine autophosphorylation of VEGF receptor bands at 225 and 220 kDa and another band at 80 kDa within 1 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Reversal of abnormal retinal hemodynamics in diabetic rats by acarbose, an alpha-glucosidase inhibitor.

Acarbose is an inhibitor of intestinal alpha-glucosidase and has been reported to decrease blood glucose concentrations and glycosuria in diabetic patients and animals. In this study we investigated whether this drug could prevent the abnormalities detected in retinal circulation of diabetic rats. Longitudinal paired studies were performed and the changes in retinal circulation were analyzed using video based fluorescein angiography (VFA) methodology in the same animal. Baseline VFA recordings were obtained from 41 rats. These rats were separated into 4 different groups: In group A (n = 12), diabetes was induced by streptozotocin (STZ) injection and the rats were fed with acarbose (40 mg/100 g powdered chow) mixed into regular rat chow; In group B (n = 10), diabetes was induced by STZ injection and the rats were fed with normal chow; In group C (n = 9), the non-diabetic rats were fed with acarbose; In group D (n = 10), the non-diabetic rats were fed with normal chow. At the end of 2 weeks, all rats again underwent VFA recordings. Blood glucose levels and body weights of rats were monitored during the experiment. The mean blood glucose concentration of Group B was raised from 98.5 +/- 8.7 to 342 +/- 30 mg/dl after STZ injection while in Group A, this change in glucose level was partially ameliorated by acarbose (from 102 +/- 15 to 247 +/- 48 mg/dl). In Group C and D, the blood glucose levels were not significantly changed during the experiment.(ABSTRACT TRUNCATED AT 250 WORDS)

Acarbose↗
PubMed1995

Drug-dependent Ca2+ mobilization in organ-cultured rabbit ciliary processes.

This study was conducted to determine whether drug-dependent changes in cytosolic Ca2+ concentration take place in the ciliary nonpigment epithelial cells of rabbits under more physiological conditions. Iris-ciliary body from pigmented rabbits in organ-culture was loaded with a Ca(2+)-sensitive fluorescent dye, fura-2, and a video-imaging system with an image analyzer was employed. Using this method fluorescence from nonpigmented epithelial cells can be analyzed without interference from fluorescence from pigmented ciliary epithelial cells. Among the drugs studied, norepinephrine and carbachol induced Ca2+ transients in the nonpigmented epithelial cells of organ-cultured ciliary processes. Epinephrine, isoproterenol, dopamine, neuropeptide Y, and substance P at the concentration of 10(-6) to 10(-3) M failed to elicit a response. The cytosolic free Ca2+ concentration of the cells in the resting state, as determined by an in vitro calibration curve, was 166 nM. The peak free cytosolic Ca2+ concentration induced by norepinephrine was about 263 nM, and that induced by carbachol was more than 1,000 nM. The carbachol-induced response was larger in magnitude and longer in duration than that induced by norepinephrine. Not uncommonly, the carbachol-induced response lasted more than 15 min. The response was diminished in both peak height and duration by chelation of extracellular Ca2+. Atropine abolished the response showing the response being mediated by a muscarinic receptor.

Adrenergic alpha-Agonists↗
PubMed1995

Rifampicin inactivation by Bacillus species.

The ability of strains of Bacillus, Staphylococcus, Pseudomonas, and Escherichia coli to inactivate rifampicin was tested. Most Bacillus strains were found to inactivate rifampicin. Two modes of inactivation were identified; one was phosphorylation and the other involved decolorization. Presence or absence of either mechanism appeared unrelated to the phylogenetic relatedness of strains. None of the other organisms could inactivate this antibiotic.

Bacillus↗
PubMed1995

[A trial of antegrade perfusion to the lower half of the body with selective cerebral perfusion for repair of aortic arch aneurysm combined with atherosclerosis obliterance].

A 73-year-old man with aortic arch aneurysm combined with atherosclerosis obliterance underwent aortic arch replacement. As he had bilateral femoral artery obstruction, we instituted ECC with arterial perfusion through the ascending aorta. Then, the left ventricle started dilating due to mild degree of aortic regurgitation. So with selective cerebral perfusion, we perfused the lower half of the body through a Foley balloon catheter which was inserted from the aortic arch antegradely. We could perfuse with the catheter for 20 minutes for core cooling and then during repair until the catheter disturbed the operation. The Foley catheter had given us some difficulties for handling during the procedure. Based on this experience, we have made a catheter which had both a balloon for aortic occlusion and a tube for perfusion and which we could keep away from operative fields, similar to the way we used antegradely insertable aortic occlusion balloon catheter.

Aged↗
PubMed1995

[Coronary artery bypass grafting in cases with the atherosclerotic ascending aorta].

Among 172 cases of coronary artery bypass grafting, 9 cases (5%) revealed severely atherosclerotic ascending aorta. In 3 of the 9 cases, total aortic cross-clamping in the distal anastomoses of saphenous vein graft (SVG) and partial aortic clamp in the proximal anastomoses of SVG were performed. In 1 case with this technique, cerebral infarction was occurred. In 4 cases, total aortic cross-clamping in the distal and proximal anastomoses of SVG was performed. In 2 of these cases with this technique, cerebral infarctions were occurred. Hypothermic circulatory arrest was performed in 2 of the rest. In one case that was predicted to have atherosclerosis of ascending aorta prior to operation, the left internal thoracic artery was anastomosed to the left anterior descending, and SVG to the right coronary artery with hypothermia and ventricular fibrillation. And during the proximal anastomoses of SVG, hypothermic circulatory arrest without aortic clamping was initiated. In another case, atherosclerosis of ascending aorta was noted after aortic cross-clamping. Then the aorta was declamped, hypothermic circulatory arrest was established, the aorta was opened, the diseased segment was resected, and proximal anastomoses of SVG was performed to Dacron patch which was implanted for aortic wall. There were no cerebral infarction in last two patients.

Aged↗
PubMed1995

[Treatment of solid tumor by a small amount of direct current].

Solid tumor treatment was given in our animal laboratory to determine the mechanism of tumor disappearance by direct electric current, and clinical trials were done on 9 far advanced recurrent rectal cancers. Solid tumors of Yoshida sarcoma in Donryu rat were treated by 1 mA of constant direct current for 1 hour a day, for 4 days. The tumors disappeared in 13/16 within 21 days. Positive results of DNA Nick-end labeling and ladder patterns in the gel electrophoresis of DNA were observed in the regressing tumor specimen. It is considered that apoptosis is the one of the mechanisms of a disappearing tumor. As for the clinical trial concern, in 9 cases of rectal cancer, one CR and 5 PR were seen.

Aged↗
PubMed1995

[A synchronous double cancer of esophagus and stomach treated with 5-fluorouracil and consecutive low-dose cisplatin].

We report a case of double cancer of esophagus and stomach treated with 5-fluorouracil and consecutive low-dose cisplatin. The patient was a 58-year-old man with liver cirrhosis. Using upper gastrointestinal fiberscopy, a superficial depressed lesion (O-IIc) in the middle thoracic part of the esophagus and Borrmann 2 type lesion in the fundus of the stomach were also detected. Microscopic examination of the biopsy specimen revealed moderately differentiated squamous cell carcinoma and adenocarcinoma. But laparotomy could not be done due to impaired liver function (KICG 0.051, ICGR15 45.2%). The patient was treated for 28 days with continuous 24 hour infusion 5-FU, 250 mg/body/day plus low dose CD-DP, 10 mg/body daily by bolus infusion d1-5, 8-12, 15-19, 22-26. One month after the chemotherapy, both the gastric cancer and the esophageal cancer were remarkably reduced (diagnosis: PR), and showed no malignancy in the histology. There was no change in the histological findings of the esophageal lesion at 31 months after the chemotherapy. This therapy is effective for patients with gastric cancer and esophageal cancer.

Adenocarcinoma↗
PubMed1995

[Treatment of patients with chronic dissecting aortic aneurysm (DeBakey type IIIb) presenting with compromised renal perfusion].

We reviewed our experience for 6 patients of chronic dissecting aortic aneurysm (DeBakey type IIIb) with the false lumen extending into the abdominal aorta and the renal arteries being perfused from the false lumen. In three cases, whose abdominal aorta presenting with large aneurysmal lesions, we performed graft replacement of the thoracic descending aorta and abdominal aorta simultaneously. In other three cases, whose abdominal aorta presenting without aneurysmal lesions, and moreover age advanced or perioperative conditions poor, we performed graft replacement of thoracic descending aorta, using double barreled distal anastomosis technique to ensure of enough blood flow into both true and false lumens. All patients survived and there were no early postoperative complications. In 3 cases of thoracic aortic replacement alone, the mean follow-up term was 38 months, postoperative computed tomography showed neither apparent expansion of the false lumen nor compression of the true lumen of the abdominal aorta, and postoperative renal function were maintained. In conclusion, in treatment of chronic dissecting aortic aneurysm (DeBakey type IIIb) presenting with compromised renal perfusion, we considered that replacement of the thoracic descending aorta and abdominal aorta brings patient the most radical improvements. But in the patients, who are elder or in poor perioperative conditions, the replacement of thoracic descending aorta using double barreled distal anastomosis technique is one easier applicable and safer procedure to preserve the renal perfusion.

Adult↗
PubMed1995

[Absorption, distribution, excretion and metabolism of [14C] T-3761 in rats and mice].

Absorption, distribution, excretion and metabolism were studied in rats and mice after oral and intravenous administration of 5 mg/kg of [14C] T-3761. 1. [14C] T-3761 was rapidly absorbed after oral administration and maximum serum concentration of radioactivity was observed at 15 min. and at 10 min. in rats and mice, respectively. After that, radioactivity of serum declined rapidly. 2. The administered radioactivity was excreted mainly in the urine in rats and mice and excretion rate was 84% and 74%, respectively. The residual radioactivity was excreted in the feces. In both species, the urinary excretion rate after oral administration was similar to that after intravenous administration, suggesting that [14C] T-3761 was absorbed almost completely. 3. In the rat urine, over 90% of excreted radioactivity was T-3761. On the other hand, about 57% of excreted radioactivity was presumed to be glucuronide conjugate of T-3761 in the mice urine. 4. The biliary excretion of radioactivity in rats after oral administration was approximately 22%, and about 83% of those was presumed to be glucuronide conjugate. About 40% of the excreted radioactivity was reabsorbed from the intestinal tract. 5. Except gastrointestinal tract, tissue concentration of radioactivity after oral administration was high in kidney and liver. Radioactivity was widely distributed in other tissues at lower concentration than in the plasma, whereas hardly distributed in brain and spinal cord. 6. Whole body autoradiograms in rats indicate that radioactivity were widely distributed except central nervous systems. 7. The extent of the binding of [14C] T-3761 to serum protein was 23-31% and 25-34% in rats and mice, respectively.

Administration, Oral↗
PubMed1995

[Placental transfer and mammary excretion of [14C] T-3761 in rats and mice].

Placental transfer and mammary excretion of radioactivity were investigated in the pregnant rats on day 19 of pregnancy, in the pregnant mice on day 18 of pregnancy, and in the lactating rats after oral administration of 5 mg/kg of [14C] T-3761. 1. Transfer of radioactivity to fetus was observed in rats and mice and the concentration in fetus was 0.2-0.5 times higher than the maternal plasma. 2. The radioactivity was excreted into the milk and the concentration in milk was higher than those of blood levels (milk/blood = 1.3-5.8). The radioactivity in milk declined more slowly than in blood.

Animals↗
PubMed1995

[Health locus of control and acquisition of health-related information].

Relationships between acquisition of health-related information and Health Locus of Control (HLC) were investigated in 204 women aged 29-45 years, using Horige's Japanese version of Health Locus of Control (JHLC) Scales. The acquisition behavior of health-related information was obtained from the question "How often do you get health-related information by newspaper, television or magazine?" The results were as follows: 1) Women who perceived the information related directly to their personal health, acquired health-related information more often than those who did not perceive personal application of the information. 2) The technical school or junior college graduate group had the most health-related information acquisition scores. 3) The university graduate group had fewer Chance HLC beliefs and Supernatural HLC beliefs. 4) Family HLC mean scores were significantly higher in the "high family value" group than in the "high health value" group. 5) Internal HLC mean scores were significantly higher in those self-rated as "very healthy" than in those self-rated as "healthy" group. 6) Women acquiring health-related information the most had Internal HLC mean scores significantly higher than the others. Health-related information acquisition scores correlated significantly with Internal HLC mean scores and Family HLC mean scores.

Adult↗