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Biomedical subjects

Y Takagi

Publications and source records attributed to Y Takagi.

At least 307 records · Page 17Linked to original sources
PubMed1995

Preparation of casein phosphopeptides from casein micelles by ultrafiltration.

Casein phosphopeptides (CPPs), which inhibit the precipitation of calcium phosphate in the intestines, were prepared as CPP-calcium phosphate complexes from casein micelles by the ultrafiltration method. The prepared CPPs hardly contained any other peptides, so there was no need to treat with active carbon to remove the bitter peptides. The sum of alpha s1-CN-5P(f59-79) and beta-CN-4P(f1-25) comprised 60% of the CPP composition by an analysis of the elution pattern from a Q-Sepharose FF column. The content of alpha s1-CN-5P(f59-79), which has high retention ability for calcium phosphate, was the highest in the CPPs.

Animals↗
PubMed1995

Impaired activation of glucose oxidation and NADPH supply in human endothelial cells exposed to H2O2 in high-glucose medium.

The effects of glucose concentration on D-glucose oxidation and reduced nicotinamide adenine dinucleotide phosphate (NADPH) supply were studied during exposure of cultured human umbilical vein endothelial cells to hydrogen peroxide (H2O2). The activation of glucose oxidation via the pentose phosphate pathway (PPP), induced by exposure of cells to 200 mumol/l H2O2 for 1 h, was reduced by 50% (P < 0.01) in cells cultured for 5-7 days in 33 mmol/l D-glucose (HG) versus those cultured in 5.5 mmol/l D-glucose without (NG) or with (HR) 27.5 mmol/l D-raffinose. The intracellular NADPH content in HG cells, but not in NG or HR cells, was decreased by 42% (P < 0.01) by exposing cells to 200 mumol/l H2O2. The decrease in NADPH was dependent on D-glucose concentration in the medium and was prevented in glutathione (GSH)-depleted cells. The latter observation suggests that the decrease in NADPH is associated with activation of the GSH redox cycle. In the presence of 200 mumol/l H2O2, lactate release into the medium, NADH/NAD ratio, and phosphofructokinase activity in HG cells were 56, 53, and 68% greater, respectively, than in the NG group, which indicates that inhibition of glycolysis by H2O2 is less marked in the HG group compared with NG group. These results indicate that activation of the PPP was impaired in endothelial cells cultured under conditions of high-glucose and oxidative stress, resulting in a decreased supply of NADPH to various NADPH-dependent pathways, including the GSH redox cycle.

Adenosine Triphosphate↗
PubMed1995

[Isozyme analysis by enzyme immunoassay (EIA)--clinical significance and future prospect].

Serum isozymes are widely used for estimating the origin or the degree of injury. The significance and future prospect of enzyme immunoassay (EIA) for the determination of isozymes are summarized in this paper. EIAs were developed for isozymes, e.g., unstable or labile, and indistinguishable by electrophoresis or ion-exchange column chromatography EIA can measure isozyme fragments with no catalytic activity. The catalytic activity of isoenzymes released from tissues disappears immediately but immunologically active isozymes or its fragment may remain in the blood for a longer period. The determination of isozymes by EIA provides an accurate mass, released from the injury. The combination assay of catalytic activity with isozyme mass by EIA may open a new approach for the disease.

Biomarkers↗
PubMed1995

Effect of calcium supplementation on bone density and parathyroid function in elderly subjects.

The effect of calcium supplementation on secondary hyperparathyroidism of old age depends on the intestinal absorption of the calcium preparation used. In order to test the bioavailability and clinical usefulness of a new calcium preparation, heated oyster shell-seaweed calcium (HOSS Ca), a randomized, prospective, double-blind comparison of HOSS Ca, calcium carbonate and placebo was carried out in 58 hospitalized women with a mean age of 82. Group A received 900 mg Ca/day Ca as HOSS Ca, group B 900 mg Ca/day as CaCO3 and group C placebo in addition to the basic hospital diet containing approximately 600 mg Ca/day. After 18 months, lumbar spine bone mineral density (BMD) measured by DPX was 106.1 +/- 3.5% (mean +/- SEM) of the pretrial basal value in group A, 99.8 +/- 3.8% in group B and 90.9 +/- 3.4% in group C (A bu not B significantly higher than C). Midradial BMD measured by DPX was 99.3 +/- 1.3% in A, 94.8 +/- 4.0% in B and 85.5 +/- 6.2% in C. The ratio of whole body calcium content between the 12th and 18th month was 96.5 +/- 1.7% in A, 90.1 +/- 2.7% in B and 89.8 +/- 1.3% in C (A but not B significantly smaller than C). Final/baseline ratio of urinary Ca/creatinine was 91.7 +/- 11.1 in A, 111.4 +/- 18.9 in B and 125.2 +/- 12.6 in C.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

[Inborn errors of metabolism due to mutations in isoenzyme genes].

Technical advances in molecular biology have permitted the detailed study of specific genes in the pathogenesis of inborn errors of metabolism. Analysis of inborn errors of metabolism due to mutations in isoenzyme genes are summarized in this paper. GM2-gangliosidosis results from a deficiency in the activity of beta-N-acetyl hexosaminidase (HEX), and produces two types of diseases: Tay-Sachs and Sandohoff disease, also known as HEX isoenzyme (HEXA and HEXB, respectively) deficiencies. Gene analysis revealed a 5'-defect and point mutation in patients with Tay-Sachs disease. Lactic dehydrogenase has two subunits and two types of deficiency of these two subunits (M and H). Gene analysis revealed a deletion consisting of 20 bp in exon 6 in patients with M subunit deficiency and one of 2 bases in exon 3 in those with H subunit deficiency.

Humans↗
PubMed1995

[Bacterial intracavernous carotid aneurysm presented as massive epistaxis].

A 55-year-old man was admitted with complaints of headache, diplopia, fever and swelling of the right eyelid. Physical examination revealed low grade fever of 37.6 degrees C, but no evidence of infectious focus was detected. The neurological examination disclosed right abducens nerve palsy. An initial routine blood count showed an increased white blood cell count of 11,800/microliters. The erythrocyte sedimentation rate was 93mm and the C-reactive protein level was 3.6mg/dl. Massive epistaxis and hypovolemic shock developed on the 14th day while the patient was receiving antibiotics (CEZ, CMZ) for a possible intracranial infection. The magnetic resonance angiography of the brain and the cerebral angiography demonstrated an aneurysm within the cavernous sinus, which had not been present on the admission. Since epistaxis was caused by a rupture of the aneurysm, internal carotid artery ligation was done. The signs of inflammation improved as well as patients' symptoms. The improvement while using antibiotics strongly implies that the aneurysm was a result of bacterial infection of the cavernous sinus. There have been no reports of ruptured bacterial intracavernous aneurysms presented with massive epistaxis as this case.

Aneurysm, Infected↗
PubMed1995

[Detection of K-ras mutation from malignant cells in sputum with mutant-allele specific amplification (MASA) method].

Sputum cells from 44 lung cancer patients (22 adenocarcinoma, 19 squamous cell carcinoma and 3 small cell carcinoma cases) were examined to contain mutant K-ras genes. The mutant-allele-specific amplification (MASA) method was used for detection of K-ras point mutations. The reaction was designed to amplify only mutant codons with polymerase chain reaction (PCR). Codons 12, 13 and 61 were studied with synthesized primers. Two cases (primary adenocarcinoma of the lung and pancreas adenocarcinoma with lung metastasis) were positive for point mutations at codon 12. The mutation of GGT to GTT was found in the first case and to GAT in the second one. Further experiments with colony hybridization revealed the mutations were found in 1% of alleles in both cases. There were no point mutations found at codon 13 nor 61. Our experiments showed it is possible to detect K-ras mutation in sputum cells from lung cancer patients, with MASA method.

Adenocarcinoma↗
PubMed1995

[Marked dilatation of the bilateral common carotid artery: a case report].

We reported a rare case of marked dilatation of the bilateral common carotid artery (CCA) associated with stenosis of the left middle cerebral artery (MCA). A 64-year-old female was admitted with right hemiparesis and dysarthria. She was hospitalized 2 years ago for cholecystitis. For 5 years, she has been under medical treatment for hypertension, diabetes mellitus, hyperlipidemia, cardiac failure associated with hypertrophic cardiomyopathy, and atrial fibrillation. Brain CT scan showed infarction of the left corona radiata. Angiography revealed marked dilatation of the bilateral CCA and the internal carotid artery (ICA), moderate dilatation of the innominate artery and the right subclavian artery, kinking of the right CCA, diverticular outpouching of the left ICA, and stenosis of the right external carotid artery and the left MCA. Breast CT scan revealed moderate dilatation and marked calcification of the ascending aorta and the aortic arch. Laboratory examination did not show any sign of inflammation, rheumatoid factor (RA), antistreptolysis-O (ASLO) and antinucleotic antibody. Based on the clinical course, radiological findings and laboratory data, possible diagnosis of the dilatation of the bilateral CCA was discussed with particular emphasis on arteriosclerotic aneurysm and aortitis syndrome.

Aortic Arch Syndromes↗
PubMed1995

[Clinical significance of serum troponin T following coronary artery bypass surgery].

We evaluated the clinical significance of serum cardiac troponin T(TnT) following coronary artery bypass surgery (CABG) as an indicator of cardiac damage during the operation. We studied 21 patients who underwent CABG and 8 patients who underwent open thoracotomy for lung disease. In the CABG patients, serum TnT levels showed roughly biphasic release kinetics, with a peak less than 10h postoperatively and a second peak on or about the fourth day. The serum TnT levels at 0 and 10h postoperatively were 8.58 +/- 1.07 (mean +/- SE) and 9.19 +/- 1.35ng/ml, respectively, levels were 30-40 times higher than the cut-off value of 0.25ng/ml. On the fourth day after CABG, serum TnT in the 3 graft groups (7.21 +/- 2.56ng/ml) was significantly higher than in the 1 or 2 graft groups (2.57 +/- 0.05 and 2.53 +/- 0.46ng/ml, respectively). The peak serum TnT level of the patients with perioperative myocardial infarction was 34.6 +/- 5.29ng/ml, which was significantly higher than in the patients without specific evidence of perioperative infarction. On the other hand, in the patients undergoing thoracic surgery for lung disease, serum TnT showed no postoperative increase. In conclusion, serum TnT appears to be a specific marker of cardiac damage after CABG, and may be useful for the diagnosis of perioperative myocardial infarction.

Adult↗
PubMed1995

Aromatase activity in an estrogen-producing adrenocortical carcinoma in a young man.

We report on a 19-year-old man with adrenocortical adenoma producing an excessive amount of estrogen. Determination of aromatase activity of the carcinoma tissue revealed its marked enhancement compared with that of 3 normal adrenal glands and the adipose tissue. The enhanced activity of aromatase was mainly responsible for the overproduction of estrogen in the adrenocortical carcinoma of our case.

Adrenal Cortex Neoplasms↗
PubMed1995

[Rearrangement of the c-erbB2 oncogene--analysis of the gastrocolic carcinoma].

We analyzed amplification, rearrangement and point mutation of the c-erbB2 oncogene about 10 cases of the stomach cancer and 30 cases of the colon cancer. Rearrangement and amplification of the c-erbB2 oncogene were found in one case of moderately differentiated tubular adenocarcinoma of the stomach. According to the restriction map, the rearrangement apparently occurred in the region from the 5' promotor to the extracellular domain. In this case, it appeared that the over expression of ErbB2 oncoprotein detected by immunohistochemical staining was associated with rearrangement of the gene. Thus it was suggested that the point mutation of the transmembrane domain, which has been demonstrated in the rat protooncogene neu, a homolog of human c-erbB2, was not detected in this case.

Base Sequence↗
PubMed1995

[Early diagnosis and detection of successful reperfusion by mitochondrial-AST/soluble-AST ratio after acute myocardial infarction].

The change of mitochondria aspartate aminotransferase (m-AST)/soluble-AST (s-AST) ratio was examined in 22 cases of acute myocardial infarction (AMI). The m-AST/s-AST was 40.8 +/- 18.9% at admission to a hospital (2.9 +/- 1.6h). The m-AST/s-AST decreased to normal value rapidly after peak and then increased again gradually. The decrease ratio of m-AST/s-AST per minute at early stage of 8 cases, who were succeeded to reperfusion, was 0.28 +/- 0.20%, and that was significantly higher than of conventionally treated 7 cases and non-reperfused 7 cases (0.11 +/- 0.07%). These results indicated that (1) m-AST/s-AST may be an excellent indicator for AMI in early stage. (2) The decrease ratio of m-AST/s-AST would predict whether reperfusion is successful or not at an earlier stage of AMI.

Aged↗
PubMed1995

Strain and sex differences in kidney carcinogenesis in rats treated with N-ethyl-N-hydroxyethylnitrosamine and uracil.

We earlier demonstrated that simultaneous administration of EHEN and uracil for 3 weeks resulted in enhancement of renal carcinogenesis in F344 female rats. Therefore, to establish a model of renal carcinogenesis in rats that can induce advanced renal carcinoma at a high incidence, differences in the susceptibility to N-ethyl-N-hydroxyethylnitrosamine (EHEN) and uracil of the kidneys in male and female rats of two strains were examined. Group 1 (male Wistar rats), group 2 (female Wistar rats), group 3 (male F344 rats), and group 4 (female F344 rats) received a 3-week simultaneous administration of 0.05% EHEN in the drinking water and 3% uracil in the diet after one week's acclimation. In all the above four groups, the rats were thereafter given a basal diet and water without chemical addition for a 29-week period. Group 5 (male Wistar rats), group 6 (female Wistar rats), group 7 (male F344 rats) and group 8 (female F344 rats) received no chemicals for the entire 33 weeks. At the end of the experiment, renal adenocarcinomas were found in 85, 68, 14 and 0% of the rats in groups 1, 2, 3 and 4, respectively. The incidence of adenomas and adenocarcinomas in Wistar rats were significantly greater than in F344 rats (p < 0.0001). These findings indicate strain and possibly sex differences in kidney carcinogenesis in rats treated with EHEN and uracil, and simultaneous administration of the two agents to male Wistar rats might have an advantage for models to induce advanced renal carcinoma at a high incidence.

Adenocarcinoma↗
PubMed1995

Effect of a hematopoietic-promoting factor derived from porcine kidney on megakaryocyte colony formation by murine bone marrow cells.

We investigated the effect of a hematopoietic-promoting factor (HPF) purified from porcine kidney on murine megakaryocyte colony formation. Murine bone marrow cells were cultured in agar in Iscove's modified Dulbecco's medium supplemented with 10% fetal calf serum in the presence of interleukin-3 (IL-3) as a source of megakaryocyte colony-stimulating factor. HPF alone exerted only a slight effect on megakaryocyte colony formation, and the combination of HPF with IL-3 enhanced colony formation compared with IL-3 alone. At days 11 and 13, 1.9-fold and 1.7-fold enhancements were observed, respectively. When erythropoietin (Epo) was added to the combinations of IL-3 plus HPF or IL-3 plus HPF plus SCF megakaryocyte colonies were enhanced compared with the cultures without Epo. As the result of determination the ploidy distribution, more than 20% of the megakaryocytes in IL-3 plus HPF showed 32N and above ploidy, but the number of 8N and under megakaryocytes was the same as those stimulated with IL-3 alone. These results suggest that HPF stimulates both the proliferation of megakaryocyte colony-forming units and the maturation of megakaryocytes in the presence of IL-3.

Acetylcholinesterase↗
PubMed1995

Distinct roles of second and third intracellular loops of human endothelin receptors in the selective activation of G alpha s/G alpha i.

Endothelin-1 (ET-1) stimulated cAMP formation in Chinese hamster ovary cells stably expressing human wild-type ET(A) (CHO/hET(A) cells) and inhibited the formation in cells expressing human wild-type ETB (CHO/hETB cells), suggesting a selective coupling of hET(A) and hETB with G alpha s and G alpha i, respectively. To find out the receptor domain(s) that determined the selective coupling, a series of chimeric receptors between hET(A) and hETB were expressed on CHO cells and the effect of ET-1 on cAMP formation in each cell line was tested. hET(A) with the replacement of the second and/or third intracellular loop (ICLII and/or III) to the corresponding region(s) of hETB failed to transmit the stimulatory effect of ET-1. hETB with the replacement of ICLIII to the corresponding region of hET(A) failed to transmit the inhibitory effect of ET-1. A chimeric receptor with ICLII of hETB and with ICLIII of hET(A) failed to transmit either effect. These results indicated the roles of ICLII and III of hETR as major determinants of the selective coupling of hET(A)/hETB with G alpha s/G alpha i, respectively.

Animals↗