PubMed Health⌕ Search

Biomedical subjects

K Yanagida

Publications and source records attributed to K Yanagida.

At least 55 records · Page 3Linked to original sources
PubMed1996

[Demonstration and characterization of CD 46, membrane cofactor protein, in gastric cancer tissue].

CD 46, membrane cofactor protein, is a membrane protein which shows different expression and phenotypes with the organ or cell in the same individual. Previously, we reported that gastric CD 46 was expressed strongly in the mucosal epithelium, mucosa and endothelial cells of vessels in the submucosal layer. Western blot analysis revealed that gastric CD 46 was expressed as one broad band with a molecular weight ranging from 60 kDa to 69 kDa, which was different from that of lymphocytes. In this study, we investigated the differences in expression and characterization of CD 46 in gastric cancer obtained by surgery as compared with non-cancerous mucosa. Expression of CD 46 was greater in gastric cancer than in non-cancerous mucosa. In some cases, the phenotypes of CD 46 in gastric cancer were different from those in the non-cancerous tissue.

Aged↗
PubMed1996

[Expression and characterization of CD46, membrane cofactor protein, in human colonic mucosa].

CD 46, membrane cofactor protein (MCP), is a membrane regulatory glycoprotein of the complement system, and acts as a cofactor of factor I, which inactivates C3b and C4b bound on autologous cell membrane. MCP is present on human peripheral blood cells except erythrocytes, fibroblasts, epithelial and endothelial cells, and has been proved to exist in other organs including gastrointestinal tract recently. In this study the expression and characterization of MCP on normal human colonic mucosa was investigated. Immunohistochemical study showed MCP in the colonic mucosal epithelium. Western blot analysis revealed that MCP protein was expressed as a broad band of 50-65 kDa in all cases and another faint band of 43-46 kDa in 3 out of 20 cases, though the latter band was highly suspected to be originated from contaminated mononuclear cells in the colon.

Antigens, CD↗
PubMed1996

[Demonstration and characterization of CD46, membrane cofactor protein in the stomach].

CD46, membrane cofactor protein, is a glycoprotein widely present on the cell membranes and is different in molecular weight among organs or cells in the same individual. It acts as a cofactor of I of the complement system, which inactivates C3b bound to the autologous cells, and protects them from the attack of the complement. In this study CD46 was demonstrated in the stomach immunochemically. Gastric CD46 was expressed strongly in the mucosal epithelium, mucosa and endothelial cells of the vessels in the submucosal layer, whereas expressed weakly in the submucosa and muscle. Western blot analyses revealed that gastric CD46 was expressed as one broad band with molecular weight ranging from 60 kDa to 69 kDa, which was distinct from that of lymphocytes in the peripheral blood.

Aged↗
PubMed1996

[Effect of macrophage colony-stimulating factor on complement receptors and complement regulatory proteins on human peripheral white blood cells].

The effect of M-CSF and C5a on the expression of complement-related membrane proteins on the peripheral white blood cells was investigated. M-CSF or C5a was added into the suspension of the peripheral white blood cells. The expression of the complement receptors, CD35 (CR1) and CD11b/18 (CR3), and inhibitory membrane proteins, DAF and MCP, was measured by flow cytometry. M-CSF increased CR3 on polymorphonuclear cells (PMNs) and CR1, CR3, MCP and DAF on monocytes. C5a increased CR1, CR3 and DAF on PMNs, but did not affect the expression of those on monocytes. It is concluded that M-CSF possessed the activity of increase expression of both complement regulatory proteins and complement receptors of monocytes and C5a selectively affected the expression of those on PMNs.

Adult↗
PubMed1995

Intracytoplasmic sperm injection using immobilized or motile human spermatozoon.

OBJECTIVES: To investigate the efficacy of the treatments for oocyte activation on the results of intracytoplasmic sperm injection using immobilized or motile human spermatozoa. DESIGN: The protocol of intracytoplasmic sperm injection was divided into four groups according to the states of sperm used for microinjection and the treatment for oocyte activation. In group A, immobilized sperm is used. The oocyte is activated merely by aspiration of the cytoplasm into the pipette. In group B, immobilized sperm is used. Microinjected oocyte is treated with A23187. In group C, immobilized sperm is used. Electroporation is performed on the microinjected oocyte. In group D, motile sperm is used. The oocyte is activated merely by aspiration of the cytoplasm into the pipette. SETTING: The Obstetrics and Gynecology Hospital, Fukushima Medical College. PATIENTS: The subjects are the cases that had failed fertilization in standard IVF, cases of severe oligozoospermia, and cases of severe asthenozoospermia. RESULTS: No difference was found between the groups as to the survival rate and fertilizing rates of oocytes after intracytoplasmic sperm injection. The cleavage rate of oocytes was high in order of group D, C, B, A. The cleavage rate for groups D, C, and B was significantly higher than group A. Cases of pregnancy were found in groups D and B. CONCLUSION: Using motile sperm rather than immobilized sperm can be expected to produce better results in human ICSI. Activating oocytes positively is needed when immobilized sperm is used.

Cleavage Stage, Ovum↗
PubMed1995

Eight cases of gastric tumors with calcification.

Gastric tumors with calcification have been considered to be relatively rare. We treated 8 cases of tumors involving calcification, 4 cases of gastric carcinomas and 4 other cases of submucosal tumors with ulceration. These cases are reported along with a review of the cases reported in Japan.

Aged↗
PubMed1995

[Suppressed increase of C3 receptors on polymorphonuclear leukocytes by stimulation with C5a in diabetes mellitus].

This study was undertaken to clarify the susceptibility to infection of patients with diabetes mellitus. The complement system is activated through the classical and/or the alternative pathways to produce many kinds of anaphylatoxins in the inflammatory process. One of the anaphylatoxins, C5a, possesses both the strong biological activity of a chemotactic factor and the increasing effect of CR1 and CR3 expression on polymorphonuclear leukocytes (PMNs). It is well known that the complement receptors, CR1 and CR3, on PMNs play important roles in the phagocytosis. We studied the changes of the expression of these receptors on PMNs in non-insulin dependent diabetes mellitus after the stimulation with recombinant human C5a. PMNs from 11 patients with non-insulin dependent diabetes mellitus and 11 normal controls were tested. There was no significant difference of CR1 and CR3 expression on PMNs after the addition of 10 ng/ml C5a between patients with diabetes mellitus and normal controls. However, by the stimulation with 50 ng/ml C5a, the increase of the CR3 expression on PMNs of patients with diabetes mellitus was significantly smaller than normal controls (p < 0.02). The increase of the expression of CR1 on PMNs was not significantly different the two groups. It is suggested that the small increase of the CR3 expression on PMNs by the stimulation with C5a is one of the factors of the susceptibility to infection in patients with diabetes mellitus.

Adult↗
PubMed1994

Coculture of mouse embryos with cryopreserved human oviduct epithelial cells.

PURPOSE: The effect of coculturing mouse embryos with cryopreserved human oviduct epithelial cells was investigated. The cryopreserved cells in Cellbanker were thawed and cultured in Richard D. Goldsby culture medium to establish monolayers. Two-cell-stage mouse embryos were cultured alone (control group) or cocultured with monolayers established from cryopreserved cells (cryopreserved coculture group) or from fresh cells (fresh coculture group). The rates of embryo development and the qualities of the blastocysts in the three groups were compared. RESULTS: The two coculture groups had significantly higher blastocyst development rates (cryopreserved coculture group, 81.6%; fresh coculture group, 82.2%) than the control group (63.1%). The two coculture groups had significantly more blastomeres (cryopreserved coculture group, 108.3 +/- 25.9; fresh coculture group, 108.4 +/- 25.1) than the control group (87.7 +/- 31.9). CONCLUSION: The method of cryopreservation of human oviduct epithelial cells using Cellbanker is simpler than conventional cryopreservation methods. These cryopreserved human oviduct epithelial cells may provide a constant supply of cells for coculture for in vitro fertilization and embryo transfer.

Adult↗
PubMed1994

Localization of fibronectin on the surface of human spermatozoa and relation to the sperm-egg interaction.

OBJECTIVES: The mechanism of human sperm-oolemma adhesion and penetration as well as localization of fibronectin on the sperm head and its relation to fertilization were investigated. DESIGN: Sperm-oolemma interaction was examined with an in vitro assay of the human sperm-zona-free hamster egg interaction. Localization of fibronectin on the surface of human spermatozoa was observed by the back scattered electron imaging mode of the scanning electron microscopy (SEM). RESULTS: It was confirmed by observations under SEM that the anterior tip of the sperm head is the first to come into contact with the egg plasma membrane but that the equatorial segment of the sperm head is the first to be trapped by microvilli of the plasma membrane and that the postacrosomal region is first incorporated into ooplasm. Localization of fibronectin on the equatorial segment of the human sperm head was detected by SEM. Antifibronectin antibodies inhibited human sperm-oolemma adhesion significantly. CONCLUSIONS: Important involvement of fibronectin in the gamete interaction was made clear by the fact that fibronectin is localized in the region where a spermatozoon is fused first with the egg plasma membrane during fertilization and that the sperm adhering to the egg is inhibited by antifibronectin antibodies.

Animals↗
PubMed1994

Pronuclear formation and cleavage of mammalian eggs after microsurgical injection of freeze-dried sperm nuclei.

A study was conducted to evaluate the ability of mammalian oocytes to develop to the pronuclear stage and beyond if injected with freeze-dried sperm nuclei. The rate of development of hamster eggs to the pronuclear stage after microinjection of freeze-dried hamster sperm nuclei was 90%. The pronuclear formation rate of hamster eggs injected with freeze-dried human sperm nuclei was 85%. On the other hand, the rates for eggs injected with untreated sperm nuclei were 84% and 89% respectively. The survival rate of rabbit eggs microinjected with freeze-dried rabbit sperm nuclei was 64%, the fertilisation rate 56% and the cleavage rate 38%. The survival, fertilisation and cleavage rates of eggs injected with non-freeze-dried sperm nuclei were 78%, 45% and 34%, respectively. There was no difference between eggs injected with freeze-dried sperm nuclei and those injected with sperm nuclei that had not been freeze-dried. Of the viable rabbit eggs injected with freeze-dried rabbit sperm nuclei, 6% developed to the 6- to 8-cell stage 62 h after injection.

Animals↗
PubMed1993

Mechanism of gastroprokinetic effect of EM523, an erythromycin derivative, in dogs.

BACKGROUND: The pharmacological properties of EM523, a nonpeptide motilin agonist, have not been well characterized. METHODS: The prokinetic effect of EM523 on motor-stimulating activity in the stomach, duodenum, and jejunum in seventeen conscious dogs was studied using force transducers implanted long term. EM523 (0.3-10.0 micrograms/kg) and receptor antagonists were injected intravenously during the interdigestive state. RESULTS: EM523 induced phase III-like contractions in a dose-dependent manner, and the contractions were inhibited dose dependently by pretreatment with cholinergic and 5-HT3 receptor antagonists and dopamine but not by adrenoceptor and opiate antagonists or methysergide. The plasma immunoreactive motilin level was increased after EM523 to 60% of the mean maximum value during the spontaneous phase III contractions. Pretreatment with anti-canine motilin serum inhibited EM523-induced contractions by 19.2% in the motor index, but the contractile pattern was not affected. CONCLUSIONS: EM-523-induced phase III-like contractions are brought about through the cholinergic neural pathway and 5-HT3 receptors, and endogenous motilin release is partially involved.

Animals↗
PubMed1993

Induction of the acrosome reaction in human spermatozoa by human zona pellucida and effect of cervical mucus on zona-induced acrosome reaction.

OBJECTIVES: To investigate the induction of the acrosome reaction in human spermatozoa by the zona pellucida (ZP), cumulus oophorus, and cervical mucus (CM), and to examine the effect of cumulus oophorus and CM on the zona-induced acrosome reaction. DESIGN, PATIENTS, MAIN OUTCOME MEASURES: The acrosome status of spermatozoa from healthy donors that were cultured with salt-stored human ZP, cumulus oophorus, and/or cervical mucus was assessed using fluoresceinated pisum sativum agglutinin. RESULTS: The acrosome reaction rate after sperm attachment to the zona for 6 hours was 35.7% +/- 17.7%, which was higher than controls (2.8% +/- 1.9%). The acrosome reaction was not observed after passage through cumulus oophorus or CM; however, the acrosome reaction rate of spermatozoa passed through CM after the attachment to zona was 51.6% +/- 6.8%, a higher value in comparison with spermatozoa that had not passed through CM (25.6% +/- 9.4%). CONCLUSION: These data indicate that human ZP are capable of inducing the acrosome reaction in human spermatozoa; however, cumulus oophorus and CM are unable to do so. The data further provide evidence that CM promotes the zona-induced acrosome reaction in human spermatozoa.

Acrosome↗
PubMed1993

[Circulating immune complexes and anti-mite specific IgG antibody in status asthmatics--effects of methylprednisolone and analysis of an anti-complementary factor].

Serial changes of circulating immune complexes and anti-mite specific IgG antibody in the peripheral blood were measured eight times in six status asthmatics treated with high doses of methylprednisolone (MPS). Circulating immune complexes decreased to normal levels three hours after MPS administration. By contrast, anti-mite specific IgG antibody increased to beyond the normal range 14 days after MPS administration. Serum levels of IgE and allergen specific IgG4 antibody did not show any significant changes. In vitro experiments, circulating immune complexes in the sampled sera were decreased by an absorption test with anti-mite specific IgG antibody, and increased by reaction with an adequate volume of mite allergen. These facts indicate that circulating immune complexes are an anti-complementary factor working on the complement system, as previously reported, and that mite allergen and anti-mite IgG antibody relate to their conformation in status asthmatics. Clinically, MPS might possess an inhibitory effects on the formation of immune complexes and/or accelerate complement-dependent solubilization of antigen-antibody complexes, so that anti-mite specific IgG antibody increased markedly in the peripheral blood.

Adult↗
PubMed1992

Pretreatment of hamster oocytes with Ca2+ ionophore to facilitate fertilization by ooplasmic micro-injection.

The fertilization rate after ooplasmic micro-injection in mammals is low. In hamsters, micro-injection of sperm nuclei into oocytes resulted in the release of the second polar body and the formation of female and male pronuclei, but disappearance of the cortical granules was minimal. These unfavourable results seem to be associated with insufficient activation of oocytes by the current techniques of micro-injection. Therefore, we attempted to increase the fertilization rate by pretreating the oocytes with a Ca2+ ionophore, A23187 (10 microM, 3 min). Sperm nuclei were then micro-injected into the treated oocytes and 5 h later the percentage of oocytes at the pronuclear stage was examined: 53.1% for untreated controls and 85.7% for the treated group (P less than 0.05). However, when the number of pronucleate oocytes was divided by the number of A23187-activated oocytes, the percentage was 81.0% for the controls and 85.7% for the treated group. These findings suggest that pretreatment of oocytes with ionophore does not facilitate fertilization of activated oocytes, but that it indirectly enhances their development to the pronuclear stage by increasing the efficiency of egg activation.

Animals↗
PubMed1992

[Complement system in status asthmatics--analysis of anti-complementary effects induced by methylprendisolone].

Complement system was investigated in 7 patients with status asthmatics treated with large doses of methylprednisolone (MPS). Complement hemolytic activities, complement protein profile, complement fragments and circulating immune complexes were measured before, 3 and 8 hours after and 14 days after MPS administration. MPS normalized C4 and C1INH activities 6 hours after administration. MPS also decreased ACH50 6 hours after administration and D activity 3 and 6 hours after, but these activities recovered to their previous normal range within 14 days. P and H were decreased at each measurement time, and C1s was transiently decreased 6 hours after MPS administration. Complement fragment iC3b was increased at each measurement time, but fragment Bb tended to be decreased 14 days after MPS administration. The increment of anaphylatoxin C3a recovered to normal 14 days after MPS administration. In vitro experiments, MPS inhibited D and C1s activation directly, and decreased the decay of B and C4. Inhibition of C1s might also increase C1INH activity clinically. These results clarified that the alternative complement pathway was activated, and suggested that the C1 bypass pathway might be also activated in status asthmatics. It was further considered that these anti-complementary effects induced by MPS, brought about an improvement in asthmatic symptoms. Studies to identify the complement activators continued, and circulating immune complexes may possibly be one of those agents activating complement cascade.

Adult↗
PubMed1991

Cleavage of rabbit eggs after microsurgical injection of testicular spermatozoa.

A rabbit testicular spermatozoon or sperm head was injected microsurgically into the cytoplasm of each of 64 mature rabbit oocytes and 71 control eggs were pricked similarly but without sperm injection. A significant proportion of injected eggs developed pronuclei by 9 h and 19 had undergone regular cleavage to two cells and two to three cells by 20-23 h. By contrast, only two of 71 control eggs had cleaved at that time, the others having fragmented or remained at the 1-cell stage. No pregnancies were obtained after surgical transfer of the cleaved injected eggs to the oviducts of synchronized recipients. The results nevertheless provide some preliminary support for efforts to obtain live young with testicular sperm nuclei.

Animals↗