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Biomedical subjects

Y Hitomi

Publications and source records attributed to Y Hitomi.

At least 55 records · Page 3Linked to original sources
PubMed1994

[Clinical study of autologous blood transfusion in pregnant women].

The effect of autologous blood donation during the third trimester of pregnancy on the maternal circulation, the properties of blood collected in a phosplatebuffered citrate anticoagulant solution, and the clinical outcome of autologous blood donation and transfusion for pregnant women were investigated in this study. Thirty-four pregnant women with placenta previa or previous cesarean delivery underwent phlebotomies in an autologous transfusion program. Three hundred ml of blood was collected under the observation of fetal heart rate patterns and uterine contractions from 3 weeks prior to the planned date of cesarean section and a total of 900 ml of blood was stored. Electronic fetal monitoring tracings were all normal and changes in blood pressure and pulse rates were minimal during the blood donation. The decrease in hemoglobin after the removal of 900 ml of blood was only 0.6g/dl on average during the 3 weeks, since the concentration of erythropoietin in serum and the counts of reticlocyte increased in a few days after blood removal. But there were no significant changes in TAT levels in serum. Twelve out of 34 pregnant women received the autologous blood transfusion during or after cesarean delivery and the homologous transfusions were avoided. The results of this study suggested that autologous blood transfusion for pregnant women with a high incidence of blood loss at delivery, such as placenta previa or previous cesarean delivery was safe and advantageous in avoiding homologous blood transfusion.

Adult↗
PubMed1993

Extinction of expression of the PU.1/Sfpi-1 putative oncogene encoding a B-cell- and macrophage-specific transcription factor in somatic cell hybrids.

Several examples of extinction of cell type-specific gene expression have been observed following fusion of different cell types. Possible mechanisms of the extinction include loss of transcriptional activators and acquisition of repressor factors responsible for cell type-specific gene expression. In this study, we demonstrated the extinction of expression of the PU.1/Sfpi-1 putative oncogene encoding a B-cell- and macrophage-specific transcription factor when plasmacytoma cells are fused with embryonal carcinoma (EC) cells. The hybrid cells retained most chromosome complements from both parental lines including chromosome 2 on which the PU.1 gene is located. Therefore, extinction of PU.1 gene expression in the hybrids is not likely the result of chromosome segregation but rather due to a transacting negative factor(s) present in EC cells. On the contrary, expression of the PU.1 mRNA in plasmacytoma cells was not extinguished upon cell fusion with T-lymphoma cells, although the parental T-lymphoma cells did not express PU.1 transcripts. Hence, T-lymphoma cells seemed to be permissive to PU.1 gene expression, while EC cells were repressive. These results suggest that PU.1 gene expression which positively regulates some B cell- and macrophage-specific gene expression is a target of negative regulatory mechanisms during cell differentiation, and the regulatory mechanisms repressing PU.1 gene expression is different between EC cells and T-cells.

Animals↗
PubMed1993

Extinction of T cell receptor alpha-chain gene expression accompanied by loss of the lymphoid enhancer-binding factor 1 (LEF-1) in murine somatic cell hybrids.

To investigate the presence of a negative regulatory factor(s) suppressing T-cell receptor alpha-chain (TCR alpha) gene expression in non-T cells, 10 independent cell hybrid clones were generated between mouse T-cell lymphoma EL4 cells (TCR alpha+/beta+) and mouse fibroblast B82 cells. These cell hybrids showed a typical fibroblastic morphology and retained an approximate sum of chromosome numbers derived from both parental cells. No transcripts of the TCR alpha gene were detected in the cell hybrids, although the presence of the rearranged TCR alpha allele from EL4 cells was confirmed. The possibility of involvement of nuclear proteins responsible for the activity of the TCR alpha gene enhancer in the extinction of TCR alpha gene expression in the cell hybrids was examined. Nuclear proteins which bind to the lymphoid enhancer-binding factor 1 (LEF-1) binding motif present in EL4 cells disappeared in the hybrid clones, whereas no significant change was observed in DNA-binding activity of nuclear proteins to a consensus cyclic AMP response element (CRE) and the Ets-1 binding motif between the parental cells and the cell hybrids. No transcripts of the LEF-1 gene were detected in the cell hybrids, despite the retention of the LEF-1 gene and murine chromosomes 3, on which the LEF-1 allele is located, from both parental cells. These results suggest that a trans-acting negative regulatory factor(s) present in fibroblasts suppresses LEF-1 gene expression and that suppression of LEF-1 may lead to the extinction of TCR alpha gene expression in the cell hybrids.

Animals↗
PubMed1992

The effect of phlebotomy on serum erythropoietin levels in normal healthy subjects.

We evaluated endogenous serum erythropoietin (Epo) levels in 14 normal subjects (eight males and six females) after a single 400-ml phlebotomy. The subjects were followed up for 56 days. The hemoglobin (Hb) values of both males and females decreased to a nadir on days 3 to 7 post-phlebotomy. Hb values gradually increased, but did not completely recover to pre-phlebotomy levels by day 56. Serum Epo levels increased after 6 h post-phlebotomy, to 20.1 +/- 5.4 (mU/ml) in males and 20.7 +/- 7.0 in females, from the pre-phlebotomy levels of 14.6 +/- 4.0 in males and 13.4 +/- 4.1 in females, respectively. Epo levels continued to increase to peak levels of 25.5 +/- 6.3 in males and 28.7 +/- 11.5 in females on days 7 to 14 and thereafter decreased until day 56. Thus, the Epo response to a 400-ml phlebotomy was relatively small in magnitude and was not sufficient to initiate a significant increase in erythropoiesis. This finding suggests that the administration of recombinant human erythropoietin (rHu-Epo) may be effective for the prompt correction of anemia induced by autologous blood donation and for increasing the volume of predonated autologous blood.

Adult↗
PubMed1991

Alteration of serum lipoprotein metabolism by polychlorinated biphenyls and methionine in rats fed a soybean protein diet.

The effects of dietary supplementation of methionine to a 20% soybean protein isolate diet on serum lipoprotein profiles and secretion rate of VLDL in rats receiving polychlorinated biphenyls (PCB) were investigated. Serum cholesterol levels were higher in rats fed PCB or a methionine supplement than in controls. The effects of PCB and methionine were synergistic. The feeding of PCB resulted in more cholesterol in all fractions of serum lipoproteins tested, especially HDL (HDL1 and HDL2). Dietary supplementation of methionine primarily increased HDL cholesterol. The elevation of serum lipoprotein cholesterol due to PCB and/or methionine was significant in HDL1, which showed alpha-mobility. These results showed that methionine and PCB significantly influenced HDL metabolism. The secretion rate of VLDL was higher in rats fed PCB than in controls, but the addition of methionine to diets did not affect the secretion rate of VLDL cholesterol. This implies that PCB increased serum cholesterol partly through the stimulation of VLDL cholesterol secretion.

Administration, Oral↗
PubMed1991

Design, synthesis and antiinflammatory activity of a new indomethacin ester. 2-[N-[3-(3-(piperidinomethyl)phenoxy)propyl]carbamoylmethylthio]ethyl 1-(p-chlorobenzoyl)-5-methoxy-2-methyl-indole-3-acetate.

A novel indomethacin ester prodrug, 2-[N-[3-(3-(piperidinomethyl)phenoxy)propyl]carbamoylmethylthio ]ethyl 1-(p-chlorobenzoyl)-5-methoxy-2-methylindole-3-acetate (1) was prepared from a new histamine H2-receptor antagonist, N-[3-(3-(piperidinomethyl)phenoxy)propyl]-2-(2-hydroxyethylthio )acetamide (2) and indomethacin (3). The compound 1 was shown to be essentially similar to 3 in its antiinflammatory action and to almost completely inhibit carrageenin-induced hind-paw edema in the rat at a very high dose of 230 mg/kg (280 mumol/kg), which is comparable to that of 100 mg/kg (280 mumol/kg) of 3, without producing gastric lesions. On a molar basis, the acute gastric lesioning properties of 1 were near one-hundred times less than those of 3, resulting in over a twenty-fold improvement in the ratio of antiedema activity to ulcerogenicity. The effect of the co-administration of histamine H2-receptor antagonists on antiedema activity and ulcerogenicity caused by 3 is also discussed.

Animals↗
PubMed1990

Elevated gelsolin and alpha-actin expression in a flat revertant R1 of Ha-ras oncogene-transformed NIH/3T3 cells.

Expressions of gelsolin and alpha-actin have been investigated in a revertant cell line R1 and compared with the parental human activated Ha-ras oncogene-transformed NIH/3T3 (EJ-NIH/3T3), untransformed NIH/3T3 and partially revertant R2 cells. Gelsolin mRNA expression was strongest in R1 cells, intermediate in R2 and NIH/3T3 cells, and low in EJ-NIH/3T3 cells. Southern blot analysis gave neither signs of gross rearrangements nor amplification of the gelsolin gene. alpha-actin mRNA expression was restored in R1 cells to the level of NIH/3T3 cells. In R2 and EJ-NIH/3T3 cell lines, no alpha-actin transcript was detected. High gelsolin expression and restoration of alpha-actin expression may be associated with the acquirement of flat morphology and ordered cell growth pattern, which imply loss of tumorigenicity of R1 cells.

Actins↗
PubMed1989

Effect of dietary methionine and polychlorinated biphenyls on cholesterol metabolism in rats fed a diet containing soy protein isolate.

The effects of supplementation of methionine to a 20% soy protein isolate diet on serum level of cholesterol. 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity, cholesterol 7 alpha-hydroxylase activity, and biliary and fecal steroids in rats with or without receiving polychlorinated biphenyls (PCB) were investigated. Supplementation of methionine and PCB did not affect the growth. Serum level of cholesterol was higher in rats fed PCB than in controls. In rats fed PCB, addition of methionine elevated serum level of cholesterol synergistically. The activity of HMG-CoA reductase was higher in rats fed the methionine-supplemented diet than in those fed the unsupplemented diet when PCB was included in the diets. Cholesterol 7 alpha-hydroxylase activity (nmol/h.100 g body weight) was higher in rats fed PCB than in controls. Biliary secretion of bile acids was higher in rats fed PCB than in controls. On the other hand, fecal excretion of bile acids decreased in PCB-treated rats, but total steroids were not affected by PCB. In rats fed PCB, the addition of methionine did not alter cholesterol 7 alpha-hydroxylase activity and biliary and fecal steroid output. The data suggest that the increase in serum level of cholesterol due to dietary addition of methionine together with PCB would be mediated through the stimulation of hepatic synthesis of cholesterol.

Animals↗
PubMed1989

Effect of methionine and threonine on the hypercholesterolemia induced by polychlorinated biphenyls in rats fed a nonprotein diet.

It was previously reported that the hypercholesterolemia induced by polychlorinated biphenyls (PCB) was influenced by dietary protein quantity and quality. On the other hand, the supplementation of methionine and threonine to a nonprotein diet ameliorated the body weight loss and decreased the urinary urea excretion in rats. We examined the effect of methionine and threonine supplements on the hypercholesterolemia induced by PCB in rats fed a nonprotein diet. The administration of PCB increased plasma cholesterol concentration and the supplements of methionine and threonine to the nonprotein diet significantly accelerated the elevation of plasma level of cholesterol due to PCB feeding. Liver microsomal 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in rats fed the nonprotein diet was also elevated by PCB administration and the supplementation of methionine and threonine caused further inducing effect.

Animals↗
PubMed1986

New synthetic substrate for kallikrein and its application.

We developed a new synthetic substrate, Pro-Phe-Arg-alpha-naphthyl ester, for kallikrein. We found that this substrate had higher specificity and sensitivity for kallikrein and was applied for the preparation of zymogram and for the histochemical demonstration. With Pro-Phe-Arg-alpha-NE as substrate, the minimum detectable concentration of human urinary kallikrein was about 0.001 KU and then kallikrein could be determined with 25 microliter of human urine. We also found the possibility that occurring of abnormalities during pregnancy were predicted by the determination of urinary kallikrein of pregnants. Zymograms were prepared for various kinds of kallikrein using this substrate. The localization of kallikrein-like enzyme in rat kidneys was defined by the application this substrate for histochemistry. Moreover, cytochemical demonstrations of leucocytes in human blood were done using Ts-Lys-alpha-NE and Ac-Tyr-alpha-NE.

Animals↗
PubMed1986

[Pseudoaneurysm of the left ventricle serially demonstrated from on-set using two-dimensional echocardiography: a case report].

A case of so-called pseudoaneurysm of the left ventricle without pericardial adhesion, serially demonstrated by two-dimensional echocardiography, was reported. A 76-year-old man developed congestive heart failure 10 hours after gastrectomy, and was diagnosed as having acute myocardial infarction. Two-dimensional echocardiography on the 21st day after onset revealed moderate pericardial effusion and an echo-free space in the posterolateral myocardium of the left ventricle. The echo-free space gradually expanded exteriorly and formed an aneurysm, which remained unchanged after the resolution of the pericardial effusion. Clinical diagnosis of pseudoaneurysm of the left ventricle was made by left ventriculography and coronary angiography. At autopsy, there was an aneurysm measuring 2.3 X 3.0 X 5.0 cm which communicated with the left ventricle via two small ostia, 5 mm each in diameter. There was a loose fibrous adhesion between the pericardium and the epicardium. The wall of the aneurysm consisted of organized fibrous tissue without any elements of the myocardium. Both myocardium and fibrous tissue were located at the junction of the left ventricular wall and the aneurysm. It is surmised that dissection of the infarcted myocardium expanded so greatly as to form an aneurysmal cavity, resulting in the formation of a so-called pseudoaneurysm of the left ventricle after fibrous changes of the outer wall in the infarcted myocardium. Therefore, this aneurysm might be termed a "dissecting" aneurysm of the left ventricle. The hypothesis that a pseudoaneurysm is derived from a localized hemopericardium should be reconsidered.

Aged↗