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Biomedical subjects

H Hirai

Publications and source records attributed to H Hirai.

At least 109 records · Page 6Linked to original sources
PubMed2000

Congenital ileal atresia presenting as a single cyst-like lesion on prenatal sonography.

A routine prenatal sonographic examination at 37 weeks' menstrual age revealed a large sonolucent lesion with peristaltic movement in the abdomen of a fetus. After birth, the female infant showed progressive abdominal distention, and radiography showed a bubble-like dilatation of the small intestine. Exploratory laparotomy revealed ileal atresia with nearby partial torsion of the dilated small bowel. The incomplete torsion may have functioned as a check valve, inducing segmental dilatation of the ileum without proximal dilatation.

Female↗
PubMed2000

Treatment of lupus in NZB/W F1 mice with monoclonal antibody against Fas ligand.

Since Fas ligand (FasL) can induce apoptosis of Fas-bearing cells, Fas/FasL interactions can play a critical role in maintaining self-tolerance. Fas/FasL interactions in lupus-like autoimmune disease have been well characterized in studies using either Fas or FasL mutant mice. However, the effect of the defective FasL-mediated signaling on the establishment of lupus in other mouse strains, such as NZB/W (B/W) F1, remains uncertain. In the present study, we examined the effect of anti-FasL monoclonal antibody (mAb) on the development of lupus. Treatment of B/W F1 mice with anti-FasL mAb augmented IgG1- and IgG2a-type anti-dsDNA Ab production. However, treatment of B/W F1 mice with anti-FasL mAb also significantly prevented the development of lupus nephritis. These results indicate that Fas/FasL interactions not only regulate IgG-type autoantibody production, but also influence the development of lupus nephritis in B/W F1 mice.

Animals↗
PubMed2000

Interferon treatment on glomerulonephritis associated with hepatitis C virus.

We report on a 10-year-old girl with glomerulonephritis associated with hepatitis C virus infection, who was treated with interferon-alpha. On the first renal biopsy at 8 years of age, mild mesangial hypercellularity in a segmental to semiglobal pattern was present in all glomeruli. After 6 months interferon-alpha therapy, proteinuria diminished completely. However, mesangial proliferation was advanced on the second biopsy at 10 years of age. We concluded that the interferon-alpha was effective in the treatment of proteinuria despite the lack of pathological improvement.

Antiviral Agents↗
PubMed2000

Massive bleeding from multiple jejunal diverticula associated with an angiodysplasia: report of a case.

We report herein the case of a 70-year-old woman who presented with massive bleeding from multiple jejunal diverticula. She was initially admitted to our hospital with massive melena. An upper gastrointestinal endoscopic examination revealed no bleeding site. Colonoscopy revealed clotted and red blood throughout the colon, and a small diverticulum in the ascending colon which was thought to be the source of bleeding. Following admission, she was treated conservatively at first, but melena continued and the anemia did not improve despite blood transfusions. A laparotomy was performed and multiple jejunal diverticula, distributed from 10 to 40 cm distal to the ligament of Treitz, were found. A segment of the jejunum containing all diverticula was resected. The most distal diverticulum contained a clot of blood, but no ulceration was observed. A histological examination revealed many dilated blood vessels in the mucosa and submucosa of this diverticulum, which were compatible with the findings of angiodysplasia. Based on these findings, we believe that angiodysplasia was the cause of bleeding from the jejunal diverticula in this case.

Aged↗
PubMed2000

Acquired hypothyroidism in a very young infant with Omenn's syndrome.

A very young male infant with Omenn's syndrome had acquired hypothyroidism that was most likely caused by autoimmune thyroiditis. The hypothyroidism appeared at 3 months of age. These 2 rare conditions have not previously been reported occurring together. This case suggests that autoimmune thyroiditis may be another abnormal finding in Omenn's syndrome.

Follow-Up Studies↗
PubMed2000

Mobilization of hematopoietic primitive and committed progenitor cells into blood in mice by anti-vascular adhesion molecule-1 antibody alone or in combination with granulocyte colony-stimulating factor.

OBJECTIVE: One of the mechanisms for mobilization of hematopoietic stem cells and progenitor cells is alternation of adhesion molecules. We investigated the mobilization of hematopoietic progenitor cells in blood by administration of anti-vascular cell adhesion molecule (VCAM)-1 antibody (Ab) in mice. MATERIALS AND METHODS: Twelve- to 14-week old C57BL/6J mice were injected intravenously with anti-VCAM-1 Ab and anti-very late antigen (VLA)-4 Ab at a dose of 5 mg/kg for 2 days. RESULTS: The number of colony-forming cells (CFCs) in blood was increased 11.4-fold after anti-VCAM-1 Ab treatment, but the number of CFCs was not increased after treatment with anti-VLA-4 Ab. The number of colony-forming unit spleen (CFU-S) also was increased 21.6-fold in the peripheral blood by administration of anti-VCAM-1 Ab. The number of CFCs and CFU-S in the bone marrow of mice treated with anti-VCAM-1 Ab was decreased and that in the spleen also was decreased. On administration of recombinant human granulocyte colony-stimulating factor (125 microg/kg twice daily) with anti-VCAM-1 Ab, the numbers of CFCs and CFU-S were increased 141.8-fold and 439-fold, respectively. CONCLUSIONS: These observations demonstrated that administration of anti-VCAM-1 Ab induced mobilization of hematopoietic progenitor cells into blood from bone marrow and spleen and that granulocyte colony-stimulating factor has synergistic effects on anti-VCAM-1 Ab-induced mobilization.

Animals↗
PubMed2000

Long-term increase of GluR2 alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor subunit in the dispersed dentate gyrus after intrahippocampal kainate injection in the mouse.

Intrahippocampal injection of a subtoxic dose of kainate in mice has been shown to induce a dispersion of granule cells of the dentate gyrus, which is a characteristic morphological change often seen in human hippocampal sclerosis. In addition, it has been shown recently that such injections lead to recurrent hippocampal seizures and changes in glucose metabolism, which are reminiscent of temporal lobe epilepsy. Previous reports on human hippocampal sclerosis have shown an increase of the expression of the GluR2 alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate subunits in the dispersed granule cell somata. However, no such changes have been observed so far in animal models of epilepsy with hippocampal sclerosis. In this study, the expression of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor subunits was examined by immunohistochemistry following intrahippocampal injection of kainate in mice and rats. In mice, such injection induced a persistent increase of GluR2 immunoreactivity in the granule cells for up to 180 days. By contrast, GluR1 immunoreactivity was transiently increased during the first four days after the injection and progressively decreased thereafter. By contrast, intrahippocampal injection of kainate in rats did not result in granule cell dispersion and no changes in GluR1 immunoreactivity or GluR2 immunoreactivity were observed. These results show that, in addition to morphological, clinical and metabolical similarities, intrahippocampal injection of kainate results in a persistent increase of GluR2 associated with granule cell dispersion, as in human hippocampal sclerosis. These data suggest the existence of common mechanisms between granule cell dispersion and regulation of GluR2 subunits associated with hippocampal sclerosis.

Animals↗
PubMed2000

Sex chromosome differences among the three races (alpha, beta, gamma) of the snail intermediate host of Schistosoma mekongi, Neotricula aperta.

Chromosome analyses were performed on three races (alpha, beta, gamma) of Neotricula aperta which were previously reported to show variation in the chromosome number and pairing in meiosis. We used an air-drying method, which was more reliable for chromosome preparations from fresh animal tissues than a squash method. Each of the races had the same number of chromosomes, 2n=33 for males, and 2n=34 for females. The sex determination system was XO type (male: 32+X, female: 32+XX). The sex chromosome of each race was distinct in its morphology, but not in its length. Karyotyping revealed that the X-chromosome of the alpha race was metacentric (M), whereas it was acrocentric (A) in the beta and the gamma races. An association between the X-chromosome and a small autosome in meiosis suggested that a neo-Y chromosome probably lies in the terminal region of the small autosome.

Animals↗
PubMed2000

A simple method using 31P-NMR spectroscopy for the study of protein phosphorylation.

Nonradioactive 31P-NMR spectroscopy has previously been used for the study of protein phosphorylations. However, the procedures does not seem to be easy for non-experts of this field, hence, this approach has not been widely used. We introduce here a simple protocol with 31P-NMR spectroscopy to study in vitro phosphorylation in receptor proteins. The effectiveness of this method was verified using synthetic peptides and recombinant proteins of the C-terminus of the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptor, whose phosphorylations are considered to have important roles in synaptic plasticity. We show that a decrease in the pH of the sample solution after the phosphorylation reaction is critical for the separation of the phosphorylation signals. In the analysis of the C-terminal portion of the GluR2 AMPA receptor, the phosphorylation sites of which had not hitherto been well clarified, we found the presence of at least three protein kinase C (PKC) phosphorylation sites. Furthermore, this method allows prediction of the origins of each of the phosphorylation peaks. Thus, the techniques we described here is useful for examination of protein phosphorylation and permits us to safely conduct repetitive experiments.

Amino Acid Sequence↗
PubMed2000

Reduction in carbon dioxide emission, and enhancement of cell yield by control of light intensity in photomixotrophic batch culture of Marchantia polymorpha.

Photomixotrophic cultures of Marchantia polymorpha were examined under light irradiation using glucose as an organic carbon source. The activity of ribulose 1,5-bisphosphate carboxylase/oxygenase in the cells was found to be maximum at an absorbed light energy of E(c) = 8.7 x 10(2)W/kg and the respiration rate of the cells remained at a low level in the range of E(c) = 1.7 x 10(2) to 1.5 x 10(3) W/kg. Batch culture of M. polymorpha was carried out in a bioreactor while keeping the E(c) value at about 3.5 x 10(2) W/kg by regulating incident light intensity between 19 and 220 W/m2. During the culture conducted under controlled light, CO2 evolution from the reactor was effectively suppressed and the obtained cell yield was 0.88 kg dry cells/kg glucose, whereas the yield was 0.62 kg dry cells/kg glucose throughout the culture conducted at the constant incident light intensity of 50 W/m2.

Journal Article↗
PubMed2000

PRINS analysis of the telomeric sequence in seven lemurs.

We examined the chromosomal localization of the telomeric sequence, (TTAGGG)n, in seven species of the lemurs and one greater galago, as an outgroup, using the primed in-situ labeling (PRINS) technique. As expected, the telomeric sequence was identified at both ends of all chromosomes of the eight prosimians. However, six species showed a signal at some pericentromeric regions involving constitutive heterochromatin as well. The pericentromeric region of chromosome 1 of Verreaux's sifaka (Propithecus verreauxi verreauxi) was labeled with a large and intense signal. The range of the signal considerably exceeded the area of DAPI positive heterochromatin. On the other hand, in the five lemurs, a large signal was detected also in the short arm of acrocentric chromosomes. Acquisition of the large block of the telomeric sequence into the acrocentric short arm might be interpretable in terms of the tandem growth of the heterochromatic short arm and the reciprocal translocation between heterochromatic short arms involving the telomeric sequence. Subsequently, it was postulated that meta- or submetacentric chromosomes possessing the telomeric sequence at the pericentromeric region could be formed by centric fusion between such acrocentric chromosomes.

Animals↗
PubMed2000

Highly efficient suicide gene expression in hepatocellular carcinoma cells by epstein-barr virus-based plasmid vectors combined with polyamidoamine dendrimer.

The present study was aimed at devising an efficient nonviral strategy for suicide gene therapy of hepatocellular carcinoma (HCC). To improve the efficiency of DNA delivery and expression, we applied Epstein-Barr virus (EBV)-based plasmid vectors instead of conventional plasmid vectors and combined them with cationic liposome (EBV/lipoplex) or polyamidoamine dendrimer (PAAD) (EBV/polyplex). When the beta-galactosidase gene was transferred to HuH7, PLC/PRF/5, or HLE cells, < or =50-fold higher beta-galactosidase activities were demonstrated in the cells transfected with EBV vector compared with those transfected with conventional plasmid vectors. PAAD-mediated transfection of HCC with pSES.Tk (an EBV-based vector carrying the herpes simplex virus-1 thymidine kinase gene) resulted in a marked reduction in viable cell number by the addition of ganciclovir (GCV). The HCC cells transfected with pSES.Tk/PAAD showed 100- to 1000-fold higher susceptibilities to GCV than those transfected with pS.Tk (a conventional plasmid vector carrying herpes simplex virus-1 thymidine kinase gene)/PAAD. The pSES.Tk-transfected HCC cells were effectively killed by day 9 in culture with a clinically feasible concentration of GCV (25 microM), whereas the pS.Tk-transfected cells survived the culture. These results demonstrate highly efficient suicide gene transfer into various HCC cells by EBV-based plasmid vectors in vitro, suggesting the possible application of this nonviral vector system to gene therapy of HCC.

Antineoplastic Agents↗
PubMed2000

Immunogene therapy against mouse leukemia using B7 molecules.

B7 costimulatory molecules play an important role in T-cell activation. It is well known that tumor cells that express B7 molecules can elicit antitumor immunity, but little is known regarding which B7 molecule, B7-1 (CD80) or B7-2 (CD86), can do so more efficiently. To address this issue, we have introduced B7-1 or B7-2 into 8709 cells, a radiation-induced mouse myelocytic leukemic cell line, and have compared their potentials regarding the induction of antitumor immunity. Either B7-1- or B7-2-transduced monoclonal sublines, 8709/B7-1 or 8709/B7-2, respectively, diminished tumorigenicity in syngeneic C3H mice. Some reports have indicated that B7-1 is superior to B7-2 in the induction of antitumor immunity. Contrary to these results, the 8709/B7-2 lines are superior to the 8709/B7-1 lines in their capacity to induce antitumor immunity. In vivo depletion of lymphocyte subsets demonstrated that both CD4+ and CD8+ T cells were indispensable for B7-1- or B7-2-dependent antitumor immunity, whereas natural killer cells were not. These results suggest that in some circumstances, B7-2 molecule is more effective than B7-1 molecule in eliciting antitumor immunity.

Animals↗