Search PubMed⌕ Search

Biomedical subjects

H Kagawa

Publications and source records attributed to H Kagawa.

At least 91 records · Page 5Linked to original sources
PubMed1994

Development of maturational competence of oocytes of red seabream, Pagrus major, after human chorionic gonadotropin treatment in vitro requires RNA and protein synthesis.

The effects of human chorionic gonadotropin (HCG) and 17 alpha,20 beta-dihydroxy-4-pregnen-3-one (DHP) on in vitro germinal vesicle breakdown (GVBD) in oocytes obtained at different times of day from a daily spawning marine teleost, the red seabream Pagrus major, were investigated. Oocytes isolated at 0800 hr underwent GVBD in response to HCG (10 IU/ml) but not to DHP (10 ng/ml). GVBD could be induced in oocytes isolated at 1600 hr by either HCG or DHP. Oocytes underwent GVBD in response to DHP after DHP-insensitive oocytes were incubated with HCG for 30, 60, or 120 min. The effects of actinomycin D (a transcriptional inhibitor) and cycloheximide (a translational inhibitor) on HCG- and DHP-induced GVBD were also investigated. Actinomycin D (1 microgram/ml) totally inhibited HCG-induction of GVBD in oocytes isolated at 0600 and 0800 hr. Actinomycin D also significantly inhibited GVBD induced by HCG in combination with DHP in oocytes taken at 0600 and 0800 hr. Cycloheximide (1 microgram/ml) completely inhibited the inducation of GVBD by HCG or DHP, alone or in combination, in oocytes obtained at 0600, 1000, and 1400 hr. These results indicate that gonadotropin induces maturational competence (responsiveness to maturation-inducing steroid) in oocytes of red seabream. These results also suggest that gonadotropin-induced synthesis of new protein through a mechanism dependent on RNA is essential for the development of maturational competence in oocytes of red seabream.

Animals↗
PubMed1994

Insulin and insulin-like growth factors I and II induce final maturation of oocytes of red seabream, Pagrus major, in vitro.

The effects of various growth factors and peptides on in vitro germinal vesicle breakdown (GVBD) were examined in oocytes of the red seabream, Pagrus major, a daily spawning marine teleost. The oocytes used underwent GVBD in response to HCG but not to 17 alpha,20 beta-dihydroxy-4-pregnen-3-one (DHP). Insulin (1 microM) and insulin-like growth factor-I (IGF-I, 10 nM) and IGF-II (13 nM) induced GVBD. Salmon gonadotropin-releasing hormone (GnRH), chicken GnRH (100 nM), angiotensin II and III (10 micrograms/ml), inhibin A, activin A (200 ng/ml), and epidermal growth factor (1 nM) were ineffective. IGF-I was the most potent inducer of GVBD. In the presence of DHP, oocytes underwent GVBD in response to low doses of IGF-I or -II or insulin which alone were ineffective. GVBD occurred in response to DHP after oocytes were preincubated with IGF-I or with HCG. Actinomycin D inhibit GVBD induced by HCG alone or in combination with DHP, but actinomycin D did not block GVBD induced by IGF-I alone or in combination with DHP. Cycloheximide totally inhibited induction of GVBD by HCG or IGF-I, alone or in combination with DHP. These results suggest, for the first time in teleost, that growth factors, such as IGF-I, are involved in the induction of GVBD of oocytes. IGF-I appears to act directly on oocytes, and not via maturation-inducing hormone production, to induce GVBD.

Animals↗
PubMed1994

Molecular cloning of a cDNA encoding the prepro-salmon gonadotropin-releasing hormone of the red seabream.

Complementary DNA fragments encoding the prepro-salmon gonadotropin-releasing hormone ([Trp7, Leu8]GnRH, sGnRH) of the red seabream Pagrus major were amplified from mRNA of the olfactory bulbs using a reverse transcriptase-polymerase chain reaction (RT-PCR), and the full-length cDNA was cloned from a cDNA library using the PCR-amplified cDNA as a probe. The cDNA consisted of 442 bp, including an open reading frame of 270 bp which encoded the prepro-sGnRH (90 amino acid residues). The prepro-sGnRH had the same architecture as that reported in other species. It was composed of a signal peptide, sGnRH and a GnRH-associated peptide (GAP), which was connected to sGnRH by a Gly-Lys-Arg sequence. The prepro-sGnRH of the red seabream had 90% amino acid identity to the prepro-sGnRH from an African cichlid Haplochromis burtoni which belongs to the same suborder as the red seabream; however, identity was lower to the prepro-sGnRH from Atlantic salmon Salmo salar (74%) and masu salmon Oncorhynchus masou (70%). The GnRH peptide itself and the Gly-Lys-Arg sequence in the prepro-GnRH are highly conserved among vertebrates. The red seabream GAP also shows significant amino acid identity to the GAPs of the African cichlid (89%), Atlantic salmon (74%), and masu salmon (67%), but exhibits no significant identity to chicken or mammalian GAP.

Amino Acid Sequence↗
PubMed1994

Transvaginal sonographic appearance of hemorrhagic functional ovarian cysts and their spontaneous regression.

OBJECTIVES: To obtain information on the characteristic feature of transvaginal sonograms of hemorrhagic functional ovarian cysts (HFOCs) and their natural course. METHODS: Thirty-four cases of suspected HFOC based on our tentative criteria were ultrasonically followed-up for 3 months. After the study period, the sonographic findings and their changes with time were analyzed. RESULTS: Twenty-four cases were clinically diagnosed as HFOCs, as the masses disappeared naturally. At the first examination, 5 cases (20.8%) showed a diffuse echogenic pattern which seems to consist of a blood clot, 9 (37.5%) were mixed pattern with a clearly demarcated solid part, 3 (12.5%) were hyperechoic sponge-like reticular pattern and 7 (29.2%) were cysts including vague echo inside which looked cotton-like. Seven masses (29.2%) disappeared within 2 weeks and the remaining had a different sonographic appearance with time until they disappeared finally within 8 weeks. CONCLUSIONS: HFOCs show the characteristic changes in transvaginal sonographic appearance and can be diagnosed by short-term follow-up.

Female↗
PubMed1994

Effect of cepharanthin and cytochalasin D on platelet internalization of anti-glycoprotein IIb/IIIa antibodies.

The effects of cepharanthin and cytochalasin D on the internalization of anti-glycoprotein IIb/IIIa antibodies by platelets were investigated in 13 patients with chronic immune thrombocytopenic purpura who had circulating anti-glycoprotein IIb/IIIa autoantibodies. Unfixed platelets were incubated with a monoclonal anti-glycoprotein IIb/IIIa antibody (NNKY1-32) or with platelet-binding IgG from the patients (which contained anti-glycoprotein IIb/IIIa antibodies). Flow cytometry showed that the binding of NNKY1-32 to platelets was markedly decreased after incubation for 120 min compared with incubation for 10 min. This decrease was inhibited by cepharanthin but not by cytochalasin D. Platelet-binding IgG also showed markedly reduced binding after incubation for 120 min compared with 10 min, and this decrease was inhibited by both cepharanthin and cytochalasin D. Cytochalasin D inhibits platelet cytoskeletal activity while cepharanthin does not. Therefore, our results suggest that the internalization of anti-glycoprotein IIb/IIIa antibodies from the plasma of patients with immune thrombocytopenic purpura is related to platelet cytoskeletal reorganization, while the cytoskeleton did not participate in internalization of the monoclonal anti-glycoprotein IIb/IIIa antibody (NNKY1-32). Cepharanthin may be useful for studying the internalization and cycling of glycoprotein IIb/IIIa in human platelets, and it may also be potentially useful for the treatment of immune thrombocytopenic purpura.

Alkaloids↗
PubMed1994

Amyloid beta-protein precursor-rich platelet microparticles in thrombotic disease.

We investigated the association of amyloid beta-protein precursor (APP) and platelet derived microparticles in 20 normal controls and 91 patients with various diseases causing a thrombotic tendency. Compared with the controls, the mean percentage of APP-positive microparticles was significantly greater in the patients with cerebral infarction (39.1 +/- 17.7%, p < 0.001), diabetes (31.1 +/- 12.6%, p < 0.001), and uremia (30.1 +/- 14.7%, p < 0.01), but not in those with hypertension (8.2 +/- 6.3%, p = NS). Sixteen patients with cerebral infarction, 20 with diabetes, and 11 with uremia had microparticles with very high APP levels. In normal controls, 7.2 +/- 3.7% of the microparticles were positive for P-selectin, while the percentage in cerebral infarction, diabetes, uremia, and hypertension was respectively 43.5 +/- 15.1%, 40.0 +/- 12.8%, 31.8 +/- 12.2%, and 11.6 +/- 7.3%. There was a significant correlation between P-selectin and APP positivity of microparticles. Our results suggest that microparticle APP may have a regulatory influence on coagulation abnormalities.

Amyloid beta-Protein Precursor↗
PubMed1993

Addition of serum from patients with collagen diseases increases to cultured human endothelial cells production and release of von Willebrand factor.

The addition of sera from patients with collagen diseases, particularly those with vascular complications, to the supernatant of cultured vascular endothelial cells (EC) in vitro significantly increased the surface and intracellular amounts of von Willebrand factor antigen (vWF:Ag) compared with results obtained with sera from normal healthy subjects. Peak levels of vWF:Ag occurred after 24 h of in vitro culture. Moreover, the amounts of vWF:Ag secreted into the EC supernatant with patient serum added were significantly higher than the amounts secreted into EC supernatant with control serum added, even after 48 h of in vitro culture. Levels of large and intermediate multimers (LIM) of von Willebrand factor (vWF) increased in EC supernatant exposed to serum from patients with collagen diseases as compared with levels in supernatant exposed to serum from normal controls, whereas no significant differences were detected overall between adding the plasma of patients and of normal subjects. In addition, C-reactive protein (CRP) induced a time- and dose-related release of vWF:Ag from EC, while glucocorticoid did not effect the release of vWF:Ag from EC. These results suggest that the sera of patients with collagen diseases, particularly those with vascular complications, stimulate the production and release of LIM of vWF from EC.

C-Reactive Protein↗
PubMed1993

IgG inhibits the increase of platelet-associated C3 stimulated by anti-platelet antibodies.

We investigated the increase of platelet-associated IgG and complement component 3 (C3) caused by the in vitro action of anti-platelet MoAbs, and the effect of mouse and human IgG on these events. Anti-glycoprotein IIb/IIIa and anti-glycoprotein Ib MoAbs caused a slight increase of C3, but not of platelet-associated IgG. In contrast, anti-CD9 and anti-Fc gamma II receptor MoAbs caused an increase of both platelet-associated C3 and IgG. In particular, three MoAbs which activated the complement system caused a marked increase of C3. When platelet-rich plasma was treated with aspirin and prostaglandin E1 before incubation with antibodies, the increase of platelet-associated IgG was inhibited in all cases. In contrast, the increase of platelet-associated C3 was scarcely influenced. These results suggest that the binding to platelets of platelet-activating antibodies caused the increased expression of IgG molecules on the platelet surface and a possible increase of platelet-associated IgG. However, the increase of platelet-associated C3 appeared to depend on specific characteristics of the antibodies tested, such as a complement-activating effect. In addition, intact mouse or human IgG inhibited the increase of platelet-associated C3 caused by complement-activating antibodies, while F(ab')2 mouse or human IgG had no such effect. This suggested that the Fc portion of IgG may block the increase of C3 mediated by anti-platelet antibodies.

Animals↗
PubMed1993

Pharmacological studies on a new dihydrothienopyridine calcium antagonist. 3rd communication: antihypertensive effects of S-(+)-methyl-4,7-dihydro-3-isobutyl-6-methyl-4-(3-nitrophenyl)thieno[2, 3-b] pyridine-5-carboxylate in hypertensive rats and dogs.

Hypotensive and antihypertensive effects of S-312-d (S-(+)-methyl-4,7-dihydro-3-isobutyl-6-methyl-4-(3-nitrophenyl)thieno[2, 3- b]pyridine-5-carboxylate, CAS 120056-57-7) in Wistar Kyoto rat (WKY), spontaneously hypertensive rat (SHR), stroke-prone SHR (SHRSP), and DOCA-salt hypertensive rat (DOCA-HR) were compared with those of other representative calcium antagonists. The minimal effective hypotensive dose of S-312-d in WKY was 3 mg/kg p.o. and those in SHR, SHRSP, and DOCA-HR were 1 mg/kg p.o. in gum arabic suspension. The minimal antihypertensive dose of S-312-d in polyethylene glycol solution was 0.3 mg/kg p.o. in SHRSP. The antihypertensive effects of S-312-d was the most potent and long-lasting compared with the calcium antagonists, nifedipine, nicardipine, nimodipine, nilvadipine, and flunarizine. In conscious two-kidney Goldblatt-type hypertensive dogs, a significant antihypertensive effect and concomitant increases of heart rate with S-312-d at 1 mg/kg lasted for 4 to 6 h after oral administration. Determination of the plasma concentration of S-312-d by HPLC showed that more than 4.3 ng/ml of S-312-d is required for a significant antihypertensive effect. Subcutaneous administration of atenolol at 20 mg/kg 30 min before S-312-d significantly inhibited the tachycardia with S-312-d at 1 mg/kg p.o. but not its antihypertensive effect. S-312-d is considered useful for the treatment of essential hypertension and related organ disorders.

Animals↗
PubMed1993

[Plasma coagulation and fibrinolysis parameters in patients with vascular Behçet's disease, and analysis of the multimeric structure of von Willebrand factor (vWF)].

We studied the relationship between vascular complications and coagulation and fibrinolysis parameters in ten subjects with Behçet's disease. We found that patients with Behçet's disease were in a state of hypercoagulation and hyperfibrinolysis. In vascular Behçet's disease in particular, coagulation and fibrinolysis parameters appeared to be indices of vascular complications. Analysis of the multimeric structure of von Willebrand factor (vWF) revealed a tendency for large multimer of vWF to increase in patients with Behçet's disease with accompanying vascular complications, whereas such increase were not observed in patients with Behçet's disease without any vascular complications. Therefore, analysis of vWF multimeric structure and the determination of coagulation and fibrinolysis parameters in plasma appear to be useful indicators of vascular complications in Behçet's disease.

Adolescent↗
PubMed1992

Characterization of proteins released from legume seeds in hot water.

When immersed in water at 50-60 degrees, mature soybean seeds release a large amount of protein. The major protein released was basic 7S globulin (Bg), which is present in the cotyledons of soybean seeds. The released Bg consisted of the 27,000 and 16,000 subunits which were linked by disulphide bonding and glycosylated. The released Bg exhibited an identical structure with the mature Bg which was synthesized in the normal developing seeds. Proteins like Bg were also found to be released into hot water from the seeds of legume species such as azuki-bean, cowpea, mung-bean and winged-bean. Besides Bg and Bg-like proteins, a few proteins including the 9,000 hydrophobic protein in soybean, ubiquitin in cowpea and mung-bean, and Kunitz trypsin inhibitor in winged-bean, were released from the seeds in hot water.

Amino Acid Sequence↗
PubMed1992

[Assessment of ovarian tumors by transvaginal scanning and clinical significance of ultrasonic examination in postoperative follow up].

A hundred and sixty cases of ovarian tumor were preoperatively examined by transvaginal (TV) and Transabdominal (TA) scanning and accuracy of the assessment for histologic type was compared. We also examined 56 cases of postoperative ovarian cancer by ultrasonography to detect recurrent lesions. Positive predictive values for serous cysts and endometrial cysts were higher with TV than TA. Sensitivity for cancer was also high, but false negative rate was lower with TV than TA. The results showed that scatter from small particles and small mural echo in the cystic mass are visualized more clearly with TV, so that TV is more useful for assessing histological type of ovarian tumors. Sensitivity and specificity of ultrasonographic examination for detecting intraperitoneal recurrent lesions were 88.2% and 97.4%, respectively. Those for extraperitoneal lesions were 86.7% and 97.6%. Ultrasonography is suggested to be useful for detecting recurrence ovarian cancer especially for experitoneal lesions, as laparoscopy is not effective for such lesions.

Female↗
PubMed1991

Single charge change on the helical surface of the paramyosin rod dramatically disrupts thick filament assembly in Caenorhabditis elegans.

Charge interactions between alpha-helical coiled-coil proteins have been postulated to determine the alignment of many filamentous proteins, such as myosin heavy-chain rod, paramyosin and alpha-keratin. Here we determined the sequence changes in nine mutations in the unc-15 paramyosin gene of Caenorhabditis elegans, including one nonsense, four missense, one deletion and three suppressor mutations. These mutation sites were located on a molecular model, constructed by optimizing charge interactions between paramyosin rods. Remarkably, single charge reversals (e.g., glutamic acid to lysine) were found that either disrupted or restored filament assembly in vivo. The positions of the mutations within the paramyosin molecule support the models of paramyosin assembly and further suggest that the C-terminal region containing a cluster of five mutations, and a site interacting with it, play a key role in assembly. One amino acid substitution in this C-terminal region, in which there is a "weak spot", led to a loss of reactivity with one monoclonal anti-paramyosin antibody. The results demonstrate how a single amino acid substitution can alter the assembly properties of alpha-helical molecules.

Actin Cytoskeleton↗