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Biomedical subjects

K Fujiwara

Publications and source records attributed to K Fujiwara.

At least 523 records · Page 29Linked to original sources
PubMed1991

The detection of spermine and spermidine in human in vitro fertilization supernatants and their relation to early embryo-associated suppressor activity.

Suppressor activity in human IVF supernatants is dependent on the activity of monoamine oxidase present in nonheat-treated FBS and is therefore likely a polyamine. Pooled suppressive growth phase IVF supernatants were concentrated and subjected to HPLC fractionation. The inhibitory peak in the 1,000 to 2,000 d range was neutralized by antibody reactive with spermine and spermidine, and the presence of both polyamines was confirmed by TLC and by ELISA. These data suggest that IVF supernatant polyamines (spermine and spermidine) are responsible for the early embryo-associated suppressor activity correlating with pregnancy success.

Chromatography, High Pressure Liquid↗
PubMed1991

Ornithine decarboxylase induction in partially hepatectomized rat liver and modes of its stimulation by glucagon and insulin.

Hepatic ornithine decarboxylase (ODC) activity increases after partial hepatectomy and this activity is further stimulated by pharmacologic doses of glucagon and insulin. We now present data suggesting that glucagon and insulin stimulate ODC activity by distinct mechanisms. ODC activity increased progressively after partial hepatectomy and reached an initial peak at 4 h. Activity decreased to 50% of its peak value at 6 and 8 h and then rose progressively to a maximum at 12 h. Enzymatic activity was well correlated with the amount of hepatic immunoreactive ODC protein, thus suggesting that increased enzyme activity was due to increased amount of enzyme protein. Hepatic ODC mRNA increased gradually and continuously, reaching the maximal value by 12 h. In rats receiving glucagon after partial hepatectomy, ODC mRNA increased significantly by 2 h and enzyme immunoreactive protein and activity by 2 to 4 h as compared to controls. In contrast, insulin administration only induced a significant increase in enzyme immunoreactive protein and activity 10 to 12 h after partial hepatectomy. No significant changes in ODC mRNA level were observed. Our data suggest that the regulation mechanism of ODC induction following partial hepatectomy differs depending on the time after operation. Our data also suggest that while glucagon appears to regulate ODC activity by a transcriptional mechanism, insulin appears to operate at a post-transcriptional level.

Animals↗
PubMed1991

Sensitive detection of viral antigens with a new method, "laser magnet immunoassay".

A new method, "laser magnet immunoassay" (LMIA), has been developed for sensitive detection of viral antigens. Target viruses captured on microbeads were made to react with antibodies labeled with magnetite particles. In a magnetic field, magnetically labeled antigens dispersed in water were attracted to and concentrated at one point on the surface, resulting in the lifting up of a small surface area. A laser beam which was incident on the point reflected, making an interference fringe. The intensity of the fringe indicates the amount of the magnetite conjugated with antigen. A very low concentration of antigens, such as 5 particles of influenza virus and 0.1 pg/ml of human immunodeficiency virus (HIV) p24 antigen in human serum, could be detected by this method. Application of this method to diagnoses of viral diseases in early stages is discussed.

Antigens, Viral↗
PubMed1991

Ruffle formation in the evaluation of stimulatory state of hepatic macrophages in rats.

Morphological changes in hepatic macrophages after stimulation were observed with a transmission electron microscope in rats. In the normal liver ruffle formation occupied less than 30% of the cell surface facing the sinusoidal space in 21 of 25 macrophages. When the rats received a dose of carbon tetrachloride, hepatic macrophages 1 day later showed ruffle formation to the same extent as in normal rats. In contrast, in rats 6 days after a dose of Corynebacterium parvum, ruffle formation was intensified, and in 19 of 25 macrophages it was seen to occupy more than 30% of the cell surface (p less than 0.01); 9 of 10 macrophages with more than 70% of the cell surface affected belonged to these rats. Considering that hepatic macrophages at 1 or 6 days after treatment with carbon tetrachloride or Corynebacterium parvum are at the responsive or primed stages, respectively, measurement of the extent of ruffle formation in hepatic macrophages with a transmission electron microscope may provide a useful tool in estimating their stimulatory stage.

Animals↗
PubMed1991

Evidence for enhanced secretory function of hepatic macrophages after long-term ethanol feeding in rats.

Rats were pair-fed nutritionally adequate liquid diets, containing ethanol as 36% of energy or an isocaloric amount of carbohydrate for 4-6 weeks. Ruffle formation of hepatic macrophages in the periportal area observed with a transmission electron microscope (which reflects their extent in activation) was more remarkable in ethanol-fed rats than in control rats. The ability of hepatic macrophages to produce superoxide anions assessed in situ by formazan deposition after liver perfusion with nitro-blue tetrazolium and phorbol myristate acetate was enhanced after such ethanol feeding. A similar result was seen 24 h after withdrawal of ethanol feeding. These findings suggest that long-term ethanol consumption may activate hepatic macrophages in secretory function.

Animals↗
PubMed1991

[Fundamental studies on "M. TB probe assay kit" for the identification of Mycobacterium tuberculosis].

DNA probe assay kit for the identification of Mycobacterium tuberculosis was evaluated. This kit is based on beads capture method and using a 20 well assay tray. The culture isolate is suspended with 0.5 ml sterilized water in the tube containing phi 3 mm glass beads for dispersion, transferred to a well of the assay tray. After lysation and adsorption of the nucleic acids to the capture bead, 125I-DNA probe specific for the M. tuberculosis is added to the sample and hybridized for 1 hour at 65 degrees C. Hybridized probe trapped on the capture bead is quantitated using a gamma counter. This hybridization assay kit can detect more than 1 x 10(5) bacteria per assay. Using the control DNA (synthesized oligonucleotide complementary to the probe sequences) and suspension of the culture isolates, the intra assay C.V. value was 4.3% and 5.2% respectively. To compare this probe assay kit with the conventional culture identification method, a total of 144 culture isolates were examined. This test for the M. tuberculosis had 99.3% agreement with the conventional identification procedures, and demonstrated 100% sensitivity and 98.2% specificity. The suspension of culture isolates can be stocked by freezing, the samples can be assayed together when they have accumulated instead of every day. As shown in the above, this assay kit demonstrates a high level of specificity and sensitivity.(ABSTRACT TRUNCATED AT 250 WORDS)

DNA Probes↗
PubMed1991

Induction of self-reactive T cells after murine coronavirus infection.

We studied the mechanism of in vitro spontaneous lymphokine production by spleen cells from mice injected intraperitoneally with murine coronavirus stain JHM 1 month after infection, when infectious virus had already been cleared from the spleens. Removal of either CD4+ T cells or Ia+ antigen-presenting cells (APC) from the spleen cells abrogated interleukin-2 (IL-2) production. Addition of anti-CD4 or anti-Iad monoclonal antibodies to the culture suppressed IL-2 production. These results suggest that the response involved typical receptor-mediated activation of T cells. Surprisingly, reciprocal mixing experiments with a coculture of T cells from infected mice and APC from either infected or naive mice resulted in the production of IL-2. The absence of viral antigens in spleen cells 1 month after infection, as indicated by their inability to induce the proliferation of T-cell clones specific for the viral antigens, suggest that the T cells from mice 1 month after infection were not responding to the viral antigens. The inoculum components other than the virus did not induce this immune response. We also found that the frequency of self-reactive but not alloreactive IL-2-producing T cells in the spleens of infected mice was 3- to 10-fold higher than that in naive mice. These findings suggest that an increased frequency of self-reactive T cells which secrete IL-2 occurs following murine coronavirus infection. This may have important implications in the development of autoimmunelike phenomena following murine coronavirus infection.

Animals↗
PubMed1991

Growth of Tyzzer's organisms in preneoplastic hepatocytes of rats.

Tyzzer's disease in rats carrying preneoplastic or neoplastic lesions in the liver was studied histopathologically and immunohistochemically. The formation of necrotic foci and the growth of organisms were detected within both glutathione S-transferase placental type (GST-P) positive preneoplastic or neoplastic hepatocyte areas and GST-P negative areas. However, plasma glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) values and number of necrotic foci of infected animals having preneoplastic lesions in the liver were smaller than those of infected animals receiving no carcinogenic procedure. These results suggest that the environment consisted of preneoplastic hepatocytes was unsuitable for the growth of organisms as compared with that of intact hepatocytes though the organism could grow within the preneoplastic hepatocytes.

Alanine Transaminase↗
PubMed1991

Comparative studies on distribution and fine morphology of the intestinal Peyer's patches in Mongolian gerbils (Meriones unguiculatus) and mice.

The intestinal Peyer's patches (PP) were significantly different in distribution and fine morphology between Mongolian gerbils and mice. The PP of gerbils were evenly distributed from the duodenum to ileum, whereas the PP of mice were more densely distributed in the lower ileum than other parts of the intestine. In gerbils, each PP had a much greater number of lymphoid follicles than in mice, although the total number of PP was smaller. Electron microscopy revealed that the PP dome of gerbils was covered with two types of epithelial cells, one with shorter microvilli and the other with longer ones, whereas the epithelial cells of the murine PP dome was uniform-shaped with numerous medium-sized microvilli. Some dome absorptive cells of gerbils were morphologically similar to poorly differentiated crypt cells of mice, suggesting to be immature M cells.

Animals↗
PubMed1991

Detection of serum antibodies using LBC cell-grown sialodacryoadenitis (SDA) virus.

The TG strain of sialodacryoadenitis (SDA) virus propagated in LBC cell culture (TGr/LBC) reacted strongly with anti-TGr rat serum in complement fixation (CF) tests, showing much higher titers with anti-TGr rat serum than mouse hepatitis virus MHV-NuU antigen. The antigenicity was not affected after ether treatment while infectivity was lost. The TGr/LBC antigen might be useful in seromonitoring for SDA infection in rats.

Animals↗
PubMed1991

Reproductive disorders in female rats infected with sialodacryoadenitis virus.

Effects of sialodacryoadenitis virus infection on the reproduction of Wistar and Sprague-Dawley (SD) rats were studied. Estrous cycle was considerably out of order in about 40% of infected rats of both strains, starting on days 4 to 20 postinfection and persisting for 2 to 12 days. Of Wistar and SD dams infected on day 0 of gestation about 30% and 10% of the fetuses were found dead, while only 4 and 3% of non-infected dams. In severely diseased Wistar and SD dams infected on day 15 of gestation, the offspring showed death rates of 57% and 13%, respectively, because of inadequate nursing.

Animals↗
PubMed1991

Appraisal of adjuvant chemoendocrine therapy with tamoxifen plus tegafur in patients with breast cancer.

To assess chemoendocrine therapy in the adjuvant treatment of patients with Stage II or III breast cancer, 228 patients were enrolled in a 12-month trial period from January 1982 to January 1983. One hundred ninety evaluable patients were followed up for five years. The regimen in this trial consisted of intravenous administration of 13 mg of mitomycin C per m2 during the operation and 6.5 mg of the same drug per m2 on the first day, and oral administration of 600 mg of tegafur per m2 alone or supplemented with 13 mg of tamoxifen per m2 for two years. No survival advantage was observed with addition of tamoxifen to tegafur in terms of five-year survival (88.7% vs 86.6% for Stage II and 69.9% vs 82.2% for Stage III). However, there was a significant prolongation of relapse-free survival among patients receiving tegafur and tamoxifen as compared with those who received tegafur alone: 72.9% vs 55.8% (p = 0.098 in the logrank test).

Adult↗
PubMed1991

Method for in situ evaluation of superoxide production by pulmonary macrophages in the rat.

In order to investigate superoxide production by pulmonary macrophages in the rat, a route was created by ligating both the inferior and superior venae cavae and resecting the aorta after cannulation through the inferior vena cava into the right atrium of the heart. Lung perfusion was performed via this route with nitro blue tetrazolium. Although there was no formazan deposition throughout the lung, it became detectable in both alveolar and interstitial macrophages when phorbol myristate acetate was added to the perfusate. This deposition was markedly enhanced by previous injection of Corynebacterium parvum. The deposition disappeared after further addition of Cu(Lys)2, a scavenger of superoxide anions. This procedure may be useful for estimating in situ the ability of pulmonary macrophages to produce superoxide in the rat.

Animals↗
PubMed1991

Sialoadenitis in experimental graft-versus-host disease. An animal model of Sjögren's syndrome.

Using light microscopic, immunohistochemical, and ultrastructural techniques, we studied sialoadenitis in mice with chronic graft-versus-host disease (GVHD). To induce chronic GVHD, DBA/2 spleen cells were injected into nonirradiated (C57BL/6 x DBA/2)F1 mice. By light and electron microscopy, the submandibular gland lesion was characterized by mononuclear cell infiltration around the interlobular ducts, often with parenchymal destruction. Immunohistochemically, T cells predominated. The ratio of CD4+ to CD8+ T cells ranged from 1.9:1 to 6:1, with an average of 3.6:1. Lesser numbers of B cells, plasma cells, and macrophages were also present. Histologically, lymphocytic sialoadenitis in chronic GVHD mice was very similar to that reported in patients with chronic GVHD and Sjögren's syndrome.

Animals↗
PubMed1991

Novel oligomannose-type sugar chains derived from glucose oxidase of Aspergillus niger.

The primary structure of the N-linked sugar chains of glucose oxidase from Aspergillus niger was investigated. These sugar chains were released from the polypeptide backbone by hydrazinolysis, and the reducing ends of the sugar chains were pyridylaminated. HPLC of the pyridylamino sugar chains with an amide-silica column showed at least seven sugar chain peaks. Chemical and exoglycosidase digestion and 400 lMHz H-NMR studies of the sugar chains of lower molecular weight showed that these were novel oligomannose-type sugar chains, (Man)5-7 (GlcNAc)2, with the structure: +/- Man alpha 1----3Man alpha 1----3(Man alpha 1----6)Man alpha 1----6(+/- Man alpha 1----3Man alpha 1---3)Man )Man beta 1----4GlcNAc beta 1----4GlcNAc.

Aspergillus niger↗