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Biomedical subjects

T Takeda

Publications and source records attributed to T Takeda.

At least 793 records · Page 44Linked to original sources
PubMed1991

Reduction by interferon-alpha of levels of c-myc protein and DNA synthesis in a human hepatoma cell line mediated by inhibition of putrescine synthesis.

Interferon-alpha inhibited increases in ornithine decarboxylase, intracellular putrescine, and DNA synthesis as human hepatoma cells were stimulated to grow. Interferon-alpha inhibited the increase in the c-myc protein level, but not its mRNA level. Added putrescine abrogated the effects on c-myc protein and DNA synthesis. Interferon-alpha seemed to inhibit the increase in the c-myc protein level post-transcriptionally by reducing the putrescine level, inhibiting DNA synthesis.

Blotting, Northern↗
PubMed1991

Effect of active vitamin D3 on the levels of NADPH-dependent cytosolic 3,5,3'-triiodo-L-thyronine-binding protein.

Effect of 1 alpha-OH-vitamin D3 (1 alpha-OH-D3) and 1,25-(OH)2-vitamin D3 (1,25-(OH)2-dihydroxycholecalciferol)(1,25-(OH)2-D3) on the levels of NADPH-dependent cytosolic 3,5,3'-triiodo-L-thyronine (T3)-binding protein (CTBP) was studied in rats and cultured dRLh cells. Deprivation of rats from vitamin D decreased the activity of cytosolic NADPH-dependent T3 binding in rat kidney and liver. The decrease was restored by administration of 1 alpha-OH-D3(0.2 micrograms/kg). The activity of cytosolic NADPH-dependent T3 binding was increased in the dRLh cells by addition of 1,25-(OH)2-D3 to the culture medium. The maximal binding capacity (MBC) was increased by 1,25-(OH)2-D3 without changes in the affinity constant. These results suggested that active vitamin D3 plays an important role in the regulation of cellular T3 translocation through increasing the binding capacity of NADPH-dependent cytosolic T3-binding protein.

Animals↗
PubMed1991

Detection of heat-stable enterotoxin in a cholera toxin gene-positive strain of Vibrio cholerae O1.

DNA colony hybridization with a polynucleotide clonal DNA probe for heat-stable enterotoxin of Vibrio cholerae non-O1 (NAG-ST) was used to screen 197 isolates of V. cholerae O1. Under stringent hybridizing and washing conditions, one strain (GP156) reacted with the probe. The concentrated supernatant from V. cholerae O1 GP156, heated at 100 degrees C for 5 min, elicited fluid accumulation in the suckling mice and that could be completely neutralized by an anti-NAG-ST monoclonal antibody (mAb2F). The preparation from V. cholerae O1 GP156 also inhibited the binding of mAb2F to NAG-ST in a competitive ELISA. V. cholerae O1 GP156 was confirmed to possess a gene encoding cholera toxin (CT). These results indicate that a heat-stable enterotoxin is produced by certain strains of CT-producing V. cholerae O1.

Animals↗
PubMed1991

Characterization and immunological properties of selenium-containing glutathione peroxidase induced by selenite in Chlamydomonas reinhardtii.

The selenite-induced glutathione peroxidase in Chlamydomonas reinhardtii has been purified about 323-fold with a 10% yield, as judged by PAGE. The native enzyme had an Mr of 67,000 and was composed of four identical subunits of Mr 17,000. Glutathione was the only electron donor, giving a specific activity of 193.6 mumol/min per mg of protein. L-Ascorbate, NADH, NADPH, pyrogallol, guaiacol and o-dianisidine did not donate electrons to the enzyme. In addition to H2O2, organic hydroperoxides were reduced by the enzyme. The Km values for glutathione and H2O2 were 3.7 mM and 0.24 mM respectively. The enzyme reaction proceeded by a Ping Pong Bi Bi mechanism. Cyanide and azide had no effect on the activity. The enzyme contained approx. 3.5 atoms of selenium per mol of protein. On immunoprecipitation, Chlamydomonas glutathione peroxidase was precipitated and its activity was inhibited about 90% by the antibody raised against bovine erythrocyte glutathione peroxidase. The antibody also cross-reacted with the subunits of Chlamydomonas glutathione peroxidase in Western blotting SDS/PAGE. In terms of enzymic, physico-chemical and immunological properties, the experimental results demonstrate clearly that Chlamydomonas glutathione peroxidase resembles other well-characterized glutathione peroxidases from animal sources that contain selenium.

Animals↗
PubMed1991

Administration of thyroxine in treated Graves' disease. Effects on the level of antibodies to thyroid-stimulating hormone receptors and on the risk of recurrence of hyperthyroidism.

BACKGROUND: Antibodies to thyroid-stimulating hormone (TSH) receptors that stimulate the thyroid gland cause hyperthyroidism in patients with Graves' disease, and their production during antithyroid drug treatment is an important determinant of the course of the disease. One factor that might contribute to the persistent production of antibodies to TSH receptors is stimulation of the release of thyroid antigens by TSH during antithyroid drug therapy. We therefore studied the effect of the suppression of TSH secretion by thyroxine on the levels of antibodies to TSH receptors after thyroid hormone secretion had been normalized by methimazole. METHODS AND RESULTS: The levels of antibodies to TSH receptors were measured during treatment with methimazole, either alone or in combination with thyroxine, in 109 patients with hyperthyroidism due to Graves' disease. The patients first received 30 mg of methimazole daily for six months. All were euthyroid after six months, and their mean (+/- SD) level of antibodies to TSH receptors decreased from 64 +/- 9 percent to 25 +/- 15 percent (P less than 0.01; normal, 2.9 +/- 1.4 percent). Sixty patients then received 100 micrograms of thyroxine and 10 mg of methimazole and 49 received placebo and 10 mg of methimazole daily for one year. In the thyroxine-treated group, the mean serum thyroxine concentration increased from 108 +/- 16 nmol per liter to 145 +/- 11 nmol per liter (P less than 0.01), and the level of antibodies to TSH receptors decreased from 28 +/- 10 percent to 10 +/- 3 percent after one month of combination therapy. In the patients who received placebo and methimazole, the mean serum thyroxine concentration decreased and the level of antibodies to TSH receptors did not change. Methimazole, but not thyroxine or placebo, was discontinued in each group 1 1/2 years after the beginning of treatment. The level of antibodies to TSH receptors further decreased (from 6.6 +/- 3.2 percent at the time methimazole was discontinued to 2.1 +/- 1.2 percent one year later) in the patients who continued to receive thyroxine, but it increased (from 9.1 +/- 4.8 percent to 17.3 +/- 5.8 percent during the same period) in the patients who received placebo. One patient in the thyroxine-treated group (1.7 percent) and 17 patients in the placebo group (34.7 percent) had recurrences of hyperthyroidism within three years after the discontinuation of methimazole. CONCLUSIONS: The administration of thyroxine during antithyroid drug treatment decreases both the production of antibodies to TSH receptors and the frequency of recurrence of hyperthyroidism.

Adolescent↗
PubMed1991

Purification and characterization of a heat-stable enterotoxin of Vibrio mimicus.

A heat-stable enterotoxin produced by Vibrio mimicus (VM-ST) was studied. VM-ST was purified from a culture supernatant of V. mimicus strain AQ-0915 by ammonium sulfate fractionation, hydroxyapatite treatment, ethanol extraction, column chromatography on both SP-Sephadex C-50 and DEAE-Sephadex A-25, and HPLC, and the recovery rate was about 15%. Purified VM-ST was heat-stable. VM-ST activity was cross-neutralized by anti-STh antiserum. The amino acid composition of the purified VM-ST was determined 17 amino acid residues in the following sequence: Ile-Asp-Cys-Cys-Glu-Ile-Cys-Cys-Asn-Pro-Ala-Cys-Phe-Gly-Cys-Leu-Asn. This composition and sequence were identical to those of V. cholerae non-O1-ST. These results clearly demonstrate the production of a characteristic VM-ST by V. mimicus.

Amino Acid Sequence↗
PubMed1991

Purification of cytosolic 3,5,3'-triiodo-L-thyronine(T3)-binding protein(CTBP) which regulates nuclear T3 translocation.

The NADPH-dependent cytosolic 3,5,3'-triiodo-L-thyronine(T3)-binding protein(CTBP) was purified from rat kidney using Mono Q-Sepharose, Red sepharose and T3 affinity chromatography. CTBP which was partially purified by Red Sepharose column chromatography was adsorbed to T3 affinity column in the presence of 50 uM NADPH. The CTBP was eluted from the gel with the buffer which did not contain NADPH. One molecule of the purified CTBP(58 kDa) bound one molecule of T3 with 2.44 x 10(9) M-1 of affinity constant. The purified CTBP was activated not only by NADPH but also by NADP in the presence of dithiothreitol. The NADPH-activated form did not transfer T3 to nuclei, whereas NADP transformed the NADPH-activated CTBP to active form which was able to transfer T3 to nuclei. These results suggested that CTBP-dependent transport of T3 to nucleus is controlled by NADPH and NADP.

Animals↗
PubMed1991

Therapeutic efficacy of interferon on HCV-RNA in chronic hepatitis C.

The efficacy of interferon therapy for chronic hepatitis C were evaluated by the changes of serum RNA of the hepatitis C virus (HCV) by the polymerase chain reaction. Before the treatment, HCV-RNA was detected in all of the 17 patients. 5 patients given IFN for 4 weeks, 12 cases given IFN by the 2 weeks/on 2 weeks off schedule (4 cases given 4 cycles and 8 given 6 cycles). Immediately after the treatment ended, the HCV-RNA was not detected in 12 (71%) cases. Five cases were persistently positive for HCV-RNA and showed continuously abnormal level of ALT. In 7 of 12 cases who became negative for HCV-RNA just after the treatment ended, HCV-RNA was detected again at first and 12th month after therapy. The ALT level were continuously abnormal in 4 of these 7 cases during and after the treatment, and became normal transiently in the other 3. In the 5 cases who became persistently negative (at least 1 year), ALT level decreased to normal or near-normal during follow up for more than one year. According to our results, we classified the therapeutic efficacy of IFN therapy for chronic hepatitis C. Type I response is complete response. In this type, HCV-RNA became negative persistently and ALT became normal or near-normal for at least 12 months after therapy. Type II is partial response. In this type, HCV-RNA became negative transiently and ALT level was transiently normal or poor. Type III is ineffective. In this type, HCV-RNA did not become negative and the effect for ALT was poor.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

A study of ventricular contraction sequence in complete right bundle branch block by phase analysis.

Twenty-four patients with complete right bundle branch block (CRBBB) combined with and without left axis deviation (LAD) on ECG, were compared with 17 normal subjects to evaluate the right ventricular contraction sequence and pattern in detail. Blood pool scintigrams were obtained in the left anterior oblique projection, and these images were analyzed by first component Fourier harmonics. In the normal subjects, the phase value distribution representing the pattern of ventricular contraction was almost homogeneous in both the right and left ventricles (RV & LV). In the CRBBB patients without LAD, the phase images showed apparent phase delay in the right ventricle. In the CRBBB patients with LAD, the phase images showed many different contraction patterns varying from normal to RV phase delay, owing to the effects of the hemi-block. Quantitative analysis of the absolute values, showed that the mean (RV-LV) value was 6.6 +/- 8.4 msec in the normal subjects. In the CRBBB patients without LAD, the duration of the QRS complex correlated with the mean (RV-LV) value, whereas no difference was observed between the duration of the QRS complex and the standard deviation of the right ventricle. Using phase analysis the degree of the RBBB can be determined from the phase images, and can be quantitatively analyzed as in electrical studies.

Adult↗
PubMed1991

Plasma levels of platelet-derived growth factor in normal subjects and patients with ischemic heart disease.

Plasma levels of platelet-derived growth factor (PDGF) were measured in 24 normal control subjects, 31 patients with stable angina pectoris, 25 patients with unstable angina pectoris, and 31 patients with acute myocardial infarction (AMI) by a sensitive direct radioimmunoassay. The plasma PDGF level in normal control subjects was 273 +/- 25 pg/ml; there was no significant correlation between the plasma PDGF level and age. Plasma PDGF levels in patients with unstable angina pectoris and acute myocardial infarction were significantly lower than those in normal control subjects and patients with stable angina pectoris (p less than 0.05). In patients with acute myocardial infarction the plasma PDGF level in the chronic phase was significantly higher than that in the acute phase (p less than 0.05). These observations raise the possibility that PDGF is involved in the pathophysiology of ischemic heart disease.

Adult↗
PubMed1991

Increased plasma immunoreactive endothelin-1 concentration in hypercholesterolemic rats.

This study examined the influence of hypercholesterolemia on the concentration of plasma immunoreactive (ir) endothelin-1 in rats. Plasma ir-endothelin-1, total cholesterol, triglycerides, and lipoprotein fraction concentrations were measured in three groups of rats; ie, fed a standard diet, a high cholesterol diet, or a high cholesterol diet supplemented with the antihypercholesterolemic drug clinofibrate for 4 and 8 weeks. In the rats fed cholesterol for 8 weeks, morphological changes in thoracic and abdominal aortas were examined. Plasma total cholesterol, low density lipoprotein (LDL), very low density lipoprotein (VLDL) and ir-endothelin-1 concentrations increased significantly in the cholesterol-fed rats after both 4 and 8 weeks. In the clinofibrate-treated rats, these lipid parameters and plasma ir-endothelin-1 levels after 4 and 8 weeks were significantly lower than in the cholesterol-fed rats. The plasma ir-endothelin-1 concentration was correlated with plasma total cholesterol, LDL, and VLDL concentrations in the three study groups after 4 and 8 weeks. Morphologically, neither foam cells formation nor intimal thickening was observed in rats fed the high cholesterol diet for 8 weeks. These observations indicate that hypercholesterolemia without atherosclerosis elevates the plasma ir-endothelin-1 level in rats. The observed increase in plasma ir-endothelin-1 associated with hypercholesterolemia may play a role in the initiation or development of atherosclerotic vascular lesions.

Animals↗
PubMed1991

Circulating immunoreactive endothelin in patients undergoing percutaneous transluminal coronary angioplasty.

Circulating immunoreactive endothelin (ir-ET) in the coronary sinus (CS) and the femoral artery (Ao) was measured in patients who underwent percutaneous transluminal coronary angioplasty (PTCA). Plasma ir-ET level in the CS was significantly increased from 1.6 +/- 0.8 pg/mL to 2.0 +/- 1.0 pg/mL after PTCA (P less than .05). Plasma ir-ET level in the Ao tended to increase after PTCA, but it was not significant. Plasma ir-ET level in the CS was not related to the plasma thromboglobulin level, plasma thrombin-antithrombin complex level, mean blood pressure, or heart rate. These results suggest that the increase of plasma ir-ET level in the CS may be associated with the coronary endothelial injury by PTCA.

Adult↗
PubMed1991

Effect of hypoxia on plasma immunoreactive endothelin-1 concentration in anesthetized rats.

The present study was designed to examine the possible influence of hypoxia on plasma immunoreactive (ir) endothelin-1 concentrations in anesthetized rats. Plasma ir-endothelin-1 concentration, blood pressure, heart rate, and arterial gas levels were measured 1 and 2 hours after exposure to normoxic (20% O2), mildly hypoxic (16% O2), and severely hypoxic (12% O2) gas. Mean blood pressure and heart rate were significantly decreased and the plasma ir-endothelin-1 concentration was significantly increased in severely hypoxic rats after both 1 and 2 hours. In mildly hypoxic rats, the plasma ir-endothelin-1 concentration was also increased, but this value was not statistically significant. The plasma ir-endothelin-1 concentration was inversely correlated with arterial blood PO2 in the three study groups (normoxic, mildly hypoxic, and severely hypoxic rats) after 1 hour (n = 18, r = -.74, P less than .01), and after 2 hours (n = 18, r = .71, P less than .01). Our results indicate that severe hypoxia increased the plasma ir-endothelin-1 level in anesthetized rats. The observed increase in plasma ir-endothelin-1 level may represent a compensatory mechanism against the blood pressure reduction associated with severe hypoxia.

Anesthesia↗
PubMed1991

Developmental capacity of bovine oocytes collected from ovaries of individual heifers and fertilized in vitro.

Bovine follicular oocytes from individual heifers (n=49) were separately matured, fertilized with frozen-thawed spermatozoa and cultured with cumulus cells. Although there were great variations in the number (mean+/-SD=19.1+/-11.9) of oocytes collected from individual heifers and the percentages of the oocytes cleaved 48 hours after insemination (mean+/-SD=69.5+/-18.4) and developed to the morula stage 7 days after insemination (mean+/-SD=10.9+/-10.9), there were significant correlations between the numbers of oocytes collected and cleaved (the correlation coefficient: r=0.9336) or developed to morula stage (r=0.6633), indicating that oocytes from different heifers have the same developmental ability after in vitro fertilization. Ten morulae and 12 blastocysts which were obtained 7 and 8 days after insemination were transferred, one by one, to each uterine horn of 11 recipients. At Day 60 of pregnancy, 8 (80%) fetuses were identified in 4 (80%) of 5 recipients into which 10 embryos were transferred at Day -1 of synchrony. However, only 3 (25%) fetuses were identified in 2 (40%) of 6 recipients into which 12 embryos were transferred at Day 0 or +1 of synchrony.

Journal Article↗
PubMed1991

Contribution of eye muscle proprioception to velocity-response characteristics of eye movements: involvement of the cerebellar flocculus.

The vestibulo-ocular reflex (VOR) and optokinetic nystagmus (OKN) were examined in alert pigmented rabbits following interruption of proprioceptive afferents from the extraocular muscles in one eye by surgical section of the ophthalmic branch of the trigeminal nerve (V1 nerve). Deficits were mainly produced in movement dynamics of the ipsilateral eye including reduction of (1) the VOR gain at a high frequency of head rotation, (2) the OKN gain and (3) the velocity of quick eye movements in the OKN. In some of the rabbits examined, the cerebellar flocculus was lesioned by local injection of kainic acid before severance of the V1 nerve. No significant additional reductions of VOR or OKN gains were produced by V1 nerve section in the flocculus-lesioned rabbits. These results suggest that proprioceptive signals from eye muscles act to improve VOR and OKN dynamics through the neuronal mechanisms involving the cerebellar flocculus.

Animals↗
PubMed1991

Pinch grafting of the open mastoid cavity.

Secondary pinch skin grafting was performed on the mastoid cavities to promote healing of the mastoid wound after ear surgery using the open technique. Pinch grafts (multiple small grafts of the epidermal layer) were transplanted in 20 patients, soon after the mastoid cavities were covered with healthy granulation tissue in a mean of 28.5 days after the initial surgery. The grafts adapted well in 18 of the 20 patients. Epidermization was complete in a mean of 11.1 days after grafting, that is, within 40 days after the initial ear surgery. On the other hand, epidermization in 10 cases without grafting was completed in a mean of 83.3 days after the ear surgery. Thus, the pinch grafts reduced healing time by more than 40 days. The secondary application of pinch grafting was beneficial for healing of exposed mastoid cavities caused by use of the open technique tympanoplasty or radical mastoidectomy.

Cholesteatoma↗