Search PubMed⌕ Search

Biomedical subjects

T Oikawa

Publications and source records attributed to T Oikawa.

At least 145 records · Page 8Linked to original sources
PubMed1993

Production and characterization of monoclonal antibodies specific for bovine oviductal glycoproteins.

Four monoclonal antibodies (MAbs) were produced in rat cells against materials obtained from the bovine oviduct. The MAbs (1H10, 2A4, 2C5, and 1B12) reacted strongly with the oviductal epithelium of cows in the follicular phase. An immunohistochemical study demonstrated that each of the MAbs bound strongly to the supranuclear cytoplasm of epithelial cells of the oviduct, but not of the stromal cells. Antigens that reacted with the MAbs were characterized by immunoblotting analysis of proteins after fractionation by SDS-PAGE under reducing conditions of oviductal flushings obtained from cows at estrus. All MAbs strongly stained a band of protein with a molecular weight (MW) of 85-97 kD. MAb 1H10 also reacted with the minor band of a 55-kD protein. Similar antigens were not detected in uterine flushings, follicular fluid, and serum. No specific immunohistochemical reactivity with the MAbs was observed with other tissues from the reproductive tract and with nonreproductive tissues. The immunohistochemical reactions were completely eliminated by pretreatment of tissues with trypsin, but not with periodic acid, results that suggest that the antigenic determinants that react with the MAbs were proteinaceous rather than carbohydrate. We have thus established clones that produce 4 MAbs that are specific for oviduct-specific glycoproteins of the cow.

Animals↗
PubMed1993

Effects of estradiol and progesterone on the cytodifferentiation of epithelial cells in the oviduct of the newborn golden hamster.

The effects of estradiol and progesterone on the cytodifferentiation of epithelial cells in the oviduct of the newborn golden hamster were investigated by electron microscopy. Consecutive daily injections of estradiol-17 beta (E2) induced various ultrastructural changes in undifferentiated epithelial cells of the neonatal oviduct. Ciliogenesis, formation of some ciliary buds, and ciliation were frequently observed in the oviductal epithelial cells on days 1-4 of consecutive treatments with E2. On days 2 and 3, the remaining cells contained well-developed Golgi apparatus and rough endoplasmic reticulum. Thereafter, a few secretory granules were observed in the cytoplasm of these cells, indicative of differentiation into secretory cells. Occasionally, secretory cells undergoing ciliogenesis or mitosis were found in the epithelium. On day 9, many fully mature ciliated and secretory cells were observed. Quantitative studies clearly showed that E2 induced the differentiation of both ciliated and secretory cells. By contrast, consecutive daily injections of progesterone significantly stimulated the appearance of ciliogenic and ciliated cells but not that of secretory cells. These results indicate that the induction of differentiation of secretory cells is a specific effect of estrogen, whereas the differentiation of ciliated cells may be closely related to effect of progesterone as well as of estrogen. It is suggested that hormonal effects on differentiation differ between ciliated and secretory cells in the oviductal epithelium of the newborn golden hamster.

Animals↗
PubMed1993

Observations by scanning electron microscopy of oviductal epithelial cells from cows at follicular and luteal phases.

The luminal surfaces of epithelial cells in various regions of the bovine oviduct from cows, at the follicular and luteal phases of the estrous cycle, were examined by scanning electron microscopy. Marked cyclic changes were observed on the surface of the epithelium in the fimbriae and ampulla, but few changes were found in the isthmus and uterotubal junction. The epithelium of the fimbriae and ampulla of oviducts in the follicular phase were densely ciliated, and the cilia concealed the apical processes of the nonciliated cells. In the luteal phase, the nonciliated cells predominated in the epithelium and most of the ciliated cells were hidden by the bulbous processes of the nonciliated cells. The epithelium of the ampullar-isthmic junction showed similar changes, but to a lesser extent. In the isthmus and at the utero-tubal junction, the apical surfaces of the nonciliated cells were flat or gently rounded during the estrous cycle. Quantitative examinations by light microscopy showed that the mean percentage of ciliated cells significantly decreased in the fimbriae and ampulla at the luteal phase, but not in the other regions. The height of ciliated cells decreased dramatically in the fimbriae, ampulla, and ampullar-isthmic junction at the luteal phase. By contrast, the height of nonciliated cells decreased significantly in the ampullar-isthmic junction, isthmus, and utero-tubal junction at the luteal phase, but not in the fimbriae and ampullae. The results demonstrate that there are regional variations and cellular differences in the cyclic changes associated with the oviductal epithelial cells in the cow.

Animals↗
PubMed1993

Synthesis and characterization of the selenium analog of glutathione disulfide.

We synthesized the selenium analog of glutathione disulfide by a liquid phase method and named it glutaselenone (i.e., gamma-L-glutamyl-L-selenocysteinylglycine) diselenide. The selenol of selenocysteine was protected by the p-methoxybenzyl group, which was removed by acidolysis with trifluoroacetic acid in the presence of thioanisol. The overall yield of the final product, glutaselenone diselenide, was about 9% based on the starting compound, Se-(p-methoxybenzyl)-L-selenocysteine. Glutaselenone diselenide showed a broad absorption band between 270 and 400 nm and circular dichroism bands around 270 nm (positive) and 330 nm (negative), which were attributable to diselenide bond.

Chromatography, High Pressure Liquid↗
PubMed1993

Stimulation of plasmin activity in cultured human fibroblast cells by Porphyromonas endodontalis.

1. Plasmin activity in the conditioned medium of Gin-1 cells, a human gingival fibroblast cell line, was stimulated by Porphyromonas endodontalis, a putative pathogen of oral submucous abscesses, in a time- and dose-dependent manner. 2. P. endodontalis stimulated the activity of plasminogen activator in both the conditioned medium and the cell lysate. The plasminogen activator in Gin-1 cells was approx. 50 kDa by zymography. 3. The conditioned medium of Gin-1 cells exposed to P. endodontalis stimulated the conversion of human serum prekallikrein to kallikrein. 4. These results suggested that P. endodontalis stimulates the plasminogen activator-plasmin system in Gin-1 cells, and that activated plasmin plays a role in the progress of periodontal tissue inflammation.

Amino Acid Sequence↗
PubMed1993

Neurological manifestations of hemorrhagic colitis in the outbreak of Escherichia coli O157:H7 infection in Japan.

An outbreak of hemorrhagic colitis associated with Escherichia coli O157:H7 occurred in a kindergarten in Saitama, Japan from September to November, 1990. Seven patients admitted to our hospital showed neurological manifestations: generalized seizures, impaired consciousness, urinary incontinence, gaze nystagmus, phrenic nerve palsy, action tremor and vertigo. Two patients died. On the basis of the clinical courses and laboratory findings of the seven patients and postmortem findings of one case, these neurological symptoms were suspected to be induced by the verotoxin elaborated by Escherichia coli O157:H7.

Bacterial Toxins↗
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↗
PubMed1993

[Fine structure of the vomeronasal organ in the house musk shrew (Suncus murinus)].

Fine structure of the vomeronasal organ (VNO) was examined in an insectivore, house musk shrew (Suncus murinus), from a viewpoint of comparative anatomy. The VNO was a pair of tubular structure, about 6mm in length, and situated at the base of the nasal septum. The medial wall of the lumen of the VNO was lined with the sensory epithelium (SE) consisting of sensory, supporting and basal cells, while the respiratory epithelium (RE) lining the lateral wall was pseudostratified and covered with microvilli. Jacobson's glands were distributed on the dorsolateral to ventrolateral side of the VNO and opened to the lumen in the transitional region from the RE to the SE. Their secretion was PAS-positive bu talcian blue-negative. Ultrastructurally, sensory cells of the SE were bipolar neurons and covered on their free surface with conspicuously long microvilli. The other ultrastructural features in sensory, supporting and basal cells were similar to those in previously reported species. The ultrastructural features of the RE were also similar to those in previous reports except that the free surface was covered with microvilli instead of cilia. In addition, a few kinds of migrating cells were often observed in both the SE and the RE. Acinar cells of Jacobson's glands possessed a round to elliptical nucleus and many large secretory granules, about 1,000 nm in diameter. Rough endoplasmic reticulum and Golgi apparatus were well developed in their cytoplasm.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Inhibition of angiogenesis by erbstatin, an inhibitor of tyrosine kinase.

Here we describe the inhibitory effect of erbstatin, a specific tyrosine kinase inhibitor, on in vivo angiogenesis. Inhibition of angiogenesis was determined in a bioassay system involving chorioallantoic membranes of growing chick embryos. Erbstatin produced a dose-dependent inhibitory action on embryonic angiogenesis. This inhibition occurred at as small a dose as 10 ng/egg and the ID50 value was 80 ng/egg. To analyze this inhibition, in vitro experiments involving vascular endothelial cells were also performed. Erbstatin affected the proliferation of vascular endothelial cells, one of angiogenic components. This inhibition was dose-dependent, the IC50 value being 3.6 microM. These data indicate that erbstatin-sensitive tyrosine kinase(s) is involved in angiogenic endothelial cell proliferation, and that experiments involving erbstatin will provide an important due to understand a mechanism of angiogenesis.

Animals↗
PubMed1993

[Influence of S-1108 on intestinal bacterial flora].

The effect of S-1108, a new oral cephem antibiotic, on intestinal bacterial flora was studied in tetra-contaminated mice and pediatric patients. S-1108 in a fine granular form was administered at a dose of 15 mg/kg once a day for 5 consecutive days to mice infected with Escherichia coli, Enterococcus faecalis, Bacteroides fragilis and Bifidobacterium breve. The viable fecal bacterial cell count of each of these 4 species of bacteria was slightly reduced in 5 days after the start of the drug administration. Five boys (weighing 12.0 to 42.0 kg) with bacterial infections were entered into this pediatric study. Their ages ranged from 2 years 4 months to 9 years 3 months. S-1108 (fine granules) was administered at a dose of 2.3 to 6.0 mg/kg, 3 times a day for 5 to 11 days. Cell counts of primary aerobes, anaerobes and total anaerobic cells decreased markedly in three patients, but in the remaining two patients the total number of aerobic and anaerobic cells did not change appreciably. Glucose-nonfermentating Gram-negative rods did not become predominant during the period of S-1108 administration. Candida became predominant in the three patients in whom the other bacteria had markedly decreased. Counts of predominant aerobic and anaerobic bacteria decreased markedly during the regimen in 3 out of 5 cases. S-1006 was detected in stools of the 3 cases at concentrations ranging from 235 to 516 micrograms/g during the administration of S-1108. Intestinal bacteria that produce beta-lactamase were not present in the feces of any of the patients. Based on these results, S-1108 (fine granules) appears to have relatively little effect on intestinal bacterial flora similarly to other new oral cephems. Because of individual differences, however, the drug may be excreted in the feces at high concentrations, and this would result in changes in intestinal bacterial flora. Therefore, attention must be given to fecal drug concentrations.

Administration, Oral↗
PubMed1993

The effect of enalapril on proteinuria in patients with chronic glomerulonephritis and renal insufficiency.

We evaluated the effect of enalapril on proteinuria in 20 patients with chronic glomerulonephritis (CGN) and renal insufficiency. Patients were accepted into the study according to the following criteria: 1) a serum creatinine (s-Cr) level over 1.5 mg/dl or a creatinine clearance (Ccr) under 70 ml/min; and 2) urinary protein (UP) over 1.0 g/day, expect for the cases with uncontrollable hypertension. We measured total protein (TP), albumin, s-Cr, Ccr, UP, and Ht during the elanapril therapy. After enalapril therapy, UP slowly decreased, and TP and albumin levels increased. The levels of s-Cr and Ccr did not vary. None of the patients required discontinuation of enalapril therapy caused by side effects, such as anemia or hyperkalemia. In conclusion, enalapril has the effect of decreasing in proteinuria and increasing TP and albumin in patients with CGN and renal insufficiency irrespective of the original diseases.

Adolescent↗
PubMed1993

[Prophylactic use of concentrated antithrombin III preparation in children with nephrotic syndrome].

Decreased plasma level of antithrombin III was assumed to be one of the major factors underlying hypercoagulable state in nephrotic syndrome. Concentrated antithrombin III preparation was given to 8 children with nephrotic syndrome with a plasma antithrombin III activity of less than 70%, to evaluate the effect on hypercoagulable state. Plasma antithrombin III activity was elevated to more than 70% in 7 of 8 children after treatment, while plasma levels of plasmin-alpha 2 plasmin inhibitor complex and FDP-D dimer were not significantly decreased. One patient developed brain infarction after the treatment, suggesting that prophylactic administration of concentrated antithrombin III preparation is not fully protective against thrombotic complications in nephrotic syndrome.

Adolescent↗
PubMed1992

Immunological characterization of oviductal glycoproteins associated with the zona pellucida of the golden hamster egg.

Three monoclonal antibodies (MAbs) were produced against materials obtained from the golden hamster oviduct. The MAbs (C11E8, C8B11, and A3D5) selectively reacted with the zona pellucida (ZP) of oviductal eggs. An immunohistochemical study demonstrated that all MAbs bound strongly to the epithelial cells of the oviduct and, to a lesser extent, of the uterus, the cervix, and the vagina. Weak reactions were also observed with some other tissues. All immunohistochemical reactions were completely eliminated by treatment of tissues with periodic acid, suggesting that the antigenic determinants that react with the MAbs are carbohydrate in nature. Antigens that reacted with the MAbs were characterized by immunoblotting analyses of 1- or 2-dimensional polyacrylamide gels after electrophoresis to fractionate tissue extracts under reducing conditions. With the oviductal extract, C11E8 and A3D5 specifically bound to broad bands that corresponded to macromolecules of more than 200 and 160 kD, respectively, whereas C8B11 reacted with a broad range of macromolecules, with the strongest reactivity being detected at molecular weights (MWs) higher than 160 kD. The macromolecules that reacted with the MAbs had carbamilation trains, suggestive of extensive microheterogeneity with respect to charge and size. Similar substances of high MW were not detected in extracts of tissues from the other reproductive organs. In addition, one MAb-positive oviductal antigen bound to the ZP of ovarian eggs, but the others did not bind to the ZP of ovarian eggs. This result indicates that the binding activity is specific for the oviductal glycoproteins. We have thus established clones that produce 3 different MAbs with strong affinity for oviduct-specific glycoproteins, one of which is associated with the ZP of the golden hamster.

Animals↗
PubMed1992

Examination by scanning electron microscopy of oviductal epithelium of the prolific Chinese Meishan pig at follicular and luteal phases.

The luminal surfaces of epithelial cells in the fimbriae, ampulla, isthmus, and utero-tubal junction of the oviducts of the prolific Chinese Meishan pig at follicular and luteal phases of the estrous cycle were examined by scanning electron microscopy. Marked cyclic changes were observed on the surfaces of cells in the fimbriae and ampulla, but little change was found in the isthmus and at the utero-tubal junction. The cells of the fimbrial epithelium in the follicular phase were densely ciliated, and the cilia partially concealed the bulbous processes of the secretory cells. In the luteal phase, the secretory cells predominated in the epithelium, and most of the ciliated cells were hidden by the processes of the secretory cells. The ampullar epithelium showed similar changes, but to a lesser extent. In the isthmus and at the utero-tubal junction, the secretory cells had many microvilli on their bulbous processes at the follicular phase, but they were flat and the microvilli were fewer in number and shorter in length during the luteal phase. Conspicuous solitary cilia protruded from the surfaces of secretory cells in the fimbriae and ampulla during the luteal phase. These results demonstrate that there are regional variations in the cyclic changes associated with the oviductal epithelial cells of the Chinese Meishan pig.

Animals↗
PubMed1992

Development of early bovine embryos to the blastocyst stage in serum-free conditioned medium from bovine granulosa cells.

Bovine granulosa cell-conditioned medium (BGC-CM) was prepared in a serum-free medium consisting of TCM 199, 5 micrograms/ml insulin, and 0.5 micrograms/ml aprotinin (TCM 199 IAP). Granulosa cells surrounded with embryos were denuded 24 to 30 h after in vitro fertilization. The proportion of denuded granulosa cell-free embryos that developed to the blastocyst stage in BGC-CM (43/219; 20%) as well as in the co-culture system (43/178; 24%) was significantly greater (P less than 0.001) than in fresh TCM 199 IAP medium (FM: 10/191; 5%), whereas the proportion of embryos that developed to the eight-cell stage was similar (P greater than 0.05) in all three culture systems (95/178; 53% in co-culture, 111/219; 51% in BGC-CM, and 86/191; 45% in FM, respectively). Higher rates of hatching and hatched blastocysts 8.5 days after in vitro fertilization were observed in co-culture (13/44; 29.5%) and in conditioned medium (8/39; 20.5%). On the other hand, no hatching or hatched blastocysts were obtained in the fresh medium (0/7; 0%). Cell numbers per blastocyst in BGC-CM (178.3 cells/blastocyst) were approximately two-fold higher than those in FM (97.1 cells/blastocyst). However, higher cell numbers (249.3 cells/blastocyst) were observed in co-culture with BGC than in BGC-CM. The embryotrophic activity in BGC-CM was stable upon freezing and thawing, lyophilization, and heating at 56 degrees C whereas activity was reduced by dilution in fresh medium, dialysis, pronase digestion, and heating at 80 degrees C. These results suggest that BGC cultured in a serum-free medium can synthesize and secrete an embryotrophic factor(s) that supports blastocyst formation in vitro beyond the 8- to 16-cell stage.

Animals↗
PubMed1992

Effect of 15-deoxyspergualin, a microbial angiogenesis inhibitor, on the biological activities of bovine vascular endothelial cells.

We found recently that 15-deoxyspergualin, an analog of spergualin, which is an antibiotic and includes a spermidine moiety in its structure, exhibits anti-angiogenic activity. We have now carried out in vitro experiments with bovine vascular endothelial cells to determine which events occurring during angiogenesis are affected by this microbial angiogenesis inhibitor. 15-Deoxyspergualin did not inhibit the production of urokinase-type plasminogen activator (u-PA) or type IV collagenase by vascular endothelial cells. The direct inhibition of u-PA activity by 15-deoxyspergualin was not observed either. The angiostatic antibiotic neither affected the migration of vascular endothelial cells nor inhibited the endothelial cell proliferation in a two-dimensional culture system. We also examined the effect of 15-deoxyspergualin on the proliferation of endothelial cells in a three-dimensional culture system involving collagen gel, in which cell growth resembles more closely the endothelial cell proliferation during in vivo angiogenesis than that in a two-dimensional culture system without collagen gel. The antibiotic inhibited cell proliferation in a dose-dependent manner, indicating that the three-dimensional culture system is useful for finding a new angiogenesis inhibitor with a different mode of action from those of angiogenesis inhibitors found by using a two-dimensional assay system; however, no cause-effect relationship has yet been established. Taken together, these results suggest the possible involvement of the inhibition of vascular endothelial cell growth by 15-deoxyspergualin in its angiogenesis-inhibitory effect. 15-Deoxyspergualin appears to be a promising candidate as an angiogenesis inhibitor for controlling aberrant angiogenic responses occurring in different states, including tumor development.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Differential expression of subspecies of polyomavirus and murine leukemia virus enhancer core binding protein, PEBP2, in various hematopoietic cells.

The core sequence of the enhancer of murine leukemia virus (MuLV) long terminal repeat is highly conserved in a large number of MuLV strains and appears to play an essential role when SL3-3 or Moloney strains induce T cell lymphoma in mice. We found by using the electrophoretic mobility shift assay that a polyomavirus enhancer core-binding protein, PEBP2, bound to this core motif of MuLV. We also noted that PEBP2 in several hematopoietic cell lines derived from B lymphocyte, macrophage and myelocyte lineages migrated significantly faster than the authentic PEBP2 detected in NIH3T3 fibroblasts. Interestingly, PEBP2 detected in the cell lines of T lymphocyte lineage appeared to contain both types, which were indistinguishable in electrophoretic mobility from those of NIH3T3 and of B lymphocyte, macrophage and myelocyte lineages. The treatment of the nuclear extract containing PEBP2 with phosphatase generated PEBP3, which is a subcomponent of PEBP2 and retained the same DNA-binding specificity as PEBP2. The altered mobility of hematopoietic cell-derived or T lymphocyte-derived PEBP2 was found to be due to the alteration of the mobility of PEBP3. Based on the distinct mobility of PEBP2/3 of T lymphocytes from those of other hematopoietic cells, we discuss the implication of PEBP2 in MuLV-induced T cell leukemia and T cell-specific gene expression.

3T3 Cells↗