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Biomedical subjects

F Kobayashi

Publications and source records attributed to F Kobayashi.

At least 127 records · Page 7Linked to original sources
PubMed1989

Relaxing action of okadaic acid, a black sponge toxin on the arterial smooth muscle.

Vasodilator responses induced by okadaic acid were investigated in isolated pig coronary artery and dog basilar artery precontracted with high K. Okadaic acid showed the relaxing effect at the concentrations above 3 x 10(-7)M. The relaxation was not inhibited by the treatment with various receptor antagonists, indomethacin, ouabain and high concentration of Ca2+ (7.5mM) and by the removal of endothelium. The intracellular Ca2+ level measured with fura 2 was not changed apparently in spite of the relaxation by okadaic acid. The maximum rate of relaxation was slowed under the conditions of low temperature (30 degrees C), anoxia and by the addition of 2-deoxy-D-glucose instead of glucose. These results suggest that okadaic acid causes vasodilation probably by its intracellular effect on Ca2+ sensitivity of contractile elements, and the ATP-producing system may be involved in this relaxation.

Animals↗
PubMed1989

Some aspects of Leucocytozoon caulleryi reinfection in chickens.

The role of first- and second-generation schizonts in acquired immunity to Leucocytozoon caulleryi in chickens was studied. The chickens, which had recovered from a primary infection with various doses of sporozoites at 22-95 days of age, were challenged with sporozoites. First-generation merozoites were found in all of the challenged chickens, but no second-generation merozoites and gametocytes were seen in 30 of 32 chickens challenged with sporozoites. Almost all of the chickens that had recovered from a primary infection with sporozoites showed complete resistance to reinfection, and those that had recovered from a primary infection with first-generation merozoites showed resistance to reinfection with sporozoites. These results indicate that the second-generation schizont of L. caulleryi appears to be more immunogenic than the first-generation schizont and that some immune factors acquired by the chickens in the second generation of schizogony may inhibit the development of second-generation schizonts.

Animals↗
PubMed1989

Transformation of oocysts from several coccidian species by heat treatment.

The transformation of sporocysts in oocysts of Eimeria caviae, E. intestinalis, E. nieschulzi, E. separata, E. tenella, Isospora canis, I. heydorni, and Toxoplasma gondii by heat treatment was examined. Fresh unsporulated oocysts from these species were heated at 50 degrees or 55 degrees C for less than 5 min and cultivated at 25 degrees C for 1 week. No transformation of sporocysts was observed in the sporulated oocysts following heating at 55 degrees C, but sporulated oocysts of Tyzzeria and Caryospora types were found in some I. canis and I. heydorni oocysts after heating at 50 degrees C followed by cultivation. A few sporulated oocysts of the Isospora type were observed in E. intestinalis oocysts after cultivation. All transformed sporulated oocysts contained eight sporozoites. In contrast, the number of sporocysts varied from two to 0. These results indicate that sporocyst formation in oocysts was affected by heat treatment. The relationship between the total numbers of sporozoites and sporocysts in the transformed oocysts was consistent with that of the "Octozoic" group classified by Hoare.

Animals↗
PubMed1989

Immunohistochemical localization and tissue levels of tumor-associated glycoproteins CA 125 and CA 19-9 in the decidua and fetal membranes at various gestational ages.

To investigate the sources and biologic significance of CA 125 and CA 19-9 in amniotic fluid, immunohistochemical and biochemical localization of these tumor-associated glycoproteins in the decidua and fetal membranes was studied. Immunohistochemically, CA 125 and CA 19-9 were localized in the cytoplasm of decidua cells and amnion epithelial cells but not in the chorion and placental tissue. Biochemically, the 12,000 X g supernatant fractions of decidua and amnion tissues contained relatively large amounts of CA 125 and CA 19-9, 73% to 96% of which was present in the cytosolic fractions of these tissues. The CA 125 levels in the amniotic fluid decreased, whereas those of CA 19-9 increased with gestation, which correlated well with the respective levels in amnion tissues. These findings suggest that amnion cells produce and secrete these glycoproteins into the amniotic cavity. However, it is possible that the decidua also secretes CA 125 into the amniotic cavity through the chorion and amnion such as in the case of prolactin.

Amniotic Fluid↗
PubMed1989

Mechanism and clinical significance of elevated CA 125 levels in the sera of pregnant women.

To clarify the mechanism of CA 125 elevation in maternal sera, serum levels of CA 125 and CA 19-9 were measured in 122 apparently healthy pregnant women (fifth to fortieth week of gestation) and 50 postpartum women (26 term deliveries and 24 second-trimester induced abortions). Serum levels of CA 125 showed an initial increase by the tenth week and then decreased to less than 35 U/ml, remaining below this level until delivery. However, within 1 hour after term delivery or second-trimester induced abortion, the CA 125 levels showed a second increase and decreased rapidly thereafter. In contrast, serum levels of CA 19-9 did not change significantly during these periods. Combined with our previous finding that the decidua contains abundant CA 125 but little CA 19-9, these results indicate that the elevated CA 125 levels in maternal sera originate from the decidual cells affected by chorionic invasion or the placental separation.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1989

Effect of antibiotics on colony formation from mouse granulocyte-macrophage progenitors (CFU-GM), megakaryocyte progenitors (CFU-M) and erythrocyte progenitors (CFU-E, BFU-E) in vitro.

Mouse bone marrow cells were cultured in vitro in semisolid medium containing various concentrations of beta-lactam antibiotics, moxalactam (LMOX), cefotetan (CTT), flomoxef (FMOX), ceftizoxime (CTZ), cefmenoxime (CMX), cefotasime (CTX), cefamandole (CMD), cefotiam (CTM), carbenicillin (CBPC) or sulbenicillin (SBPC). All of these antibiotics dose-dependently suppressed colony formation from granulocyte or macrophage progenitors (CFU-GM) and from megakaryocyte progenitors (CFU-M). The suppressive potencies of these antibiotics for both progenitors, as evaluated from the drug concentrations that induced 50% suppression of colony formation (IC50), were ranked as the weakest for CBPC and SBPC, moderate for LMOX, CTT, CMX, FMOX and CTZ, and strongest for CMD, CTX and CTM. LMOX, FMOX, CTX, CBPC and SBPC also showed dose-dependent inhibition of colony formation from erythroid progenitors (CFU-E and BFU-E). In the ranking of suppression of colony formation from CFU-E, CMD and CTX showed comparatively strong inhibition but others showed a weak effect, and in that from BFU-E, the effect was weakest for CBPC and SBPC, moderate for LMOX and FMOX, and strongest for CMD and CTX. The suppressive effect of LMOX and CMD on colony formation from each progenitor could almost be prevented by washing the cells after incubation with these antibiotics for 24 hr.

Animals↗
PubMed1989

Vitamin K-reversible hypoprothrombinemia in rats: comparison of hypoprothrombinemic changes in various strains of rats caused by vitamin K deficiency and antibiotic treatment.

Hypoprothrombinemic changes were compared in rats fed various vitamin K-deficient diets. Changes such as prolongation of prothrombin time and activated partial thromboplastin time, decrease in plasma levels of prothrombin and clotting factor VII, and increase in plasma descarboxyprothrombin, appeared in rats maintained on vitamin K-deficient diet, but in rats on ordinary diet (vitamin K-sufficient diet). As the development of hypoprothrombinemia was not significantly different among animals fed various vitamin K-deficient diets, the blood coagulation parameters were concluded to be regulated only by the vitamin K level. Following the development of hypoprothrombinemia, hemorrhaging in various organs was detected in vitamin K-deficient rats, with strain differences in the severity of hemorrhage; Fischer and Wistar strains were more sensitive than the Sprague Dawley strain. Administration of a beta-lactam antibiotic, latamoxef (LMOX), to vitamin K-deficient rats led to enhancement of the hypoprothrombinemic conditions, but LMOX-associated changes in plasma enzyme levels were not detected.

Animals↗
PubMed1989

New monoclonal antibody that specifically recognizes murine interdigitating and Langerhans cells.

A new monoclonal antibody, M1-8, that recognizes murine interdigitating cells (IDC) and Langerhans cells was obtained from a hybridoma prepared by fusion of SP2/0 mouse myeloma cells with splenic cells of rats immunized with IDC-rich cell suspension obtained from lymph nodes of athymic nude mice (BALB/c nu/nu). The specificity was assessed immunohistochemically on frozen sections of lymph nodes and epidermal sheets from both nude and normal mice. M1-8 reacted with paracortical IDC, veiled cells of the marginal sinus, and epidermal Langerhans cells in both normal and nude mice. In simultaneous staining by M1-8 and nonspecific esterase or anti-Ia or anti-Thy-1,2 antibody, the same epidermal dendritic cells were positive for all these antigens except Thy-1,2. Immunoelectron microscopy of the lymph node suspension using gold colloid particles revealed the attachment of gold particles to the cell membrane of IDC. Analysis by flow cytometry of the lymph node cell suspension showed 14 or 6% of M1-8-positive cells in nude or normal mouse, respectively. Immunohistochemical analysis showed that M1-8 also reacted with dendritic cells in the thymus and spleen and had a different distribution from F4/80. M1-8 also reacted with monocytes in bone marrow and peripheral blood, alveolar macrophages, and thioglycollate-stimulated peritoneal exudate macrophages. The antibody belongs to the immunoglobulin M class, reacts immunochemically with a glycoprotein in the cell membrane, and has a molecular mass of approximately 15 kDa.

Animals↗
PubMed1989

[Effect of soft laser on pain].

Two kinds of semiconductor laser, STOMA-LASER and Four-Luck, were used for patients having pain in the mouth and their effective rates were compared in 93 patients (133 cases). As a result, the following results were obtained. 1. The effective rate was 70.7% at the stage just after radiation. 2. Age, sex and oral hygiene were not significant for the effective rate. 3. The kinds of diseases were remarkably significant. 4. The kind of apparatus did not play any role in the effective rate as a whole, but was significant for the kinds of disease.

Facial Pain↗
PubMed1988

Analysis of the levels of CA125, carcinoembryonic antigen, and CA19-9 in the cervical mucus for a detection of cervical adenocarcinoma.

To verify whether analysis of the levels of CA125, carcinoembryonic antigen (CEA), and CA19-9 in the cervical mucus is effective for a detection of cervical adenocarcinomas or not, simultaneous measurement of these three tumor markers in the cervical mucus samples from women without gynecologic disorders, with leiomyoma, with cervical squamous cell carcinomas, and with cervical adenocarcinomas was performed. Extremely high levels of CA125 with low levels of both CEA and CA19-9 were demonstrated in the cervical mucus samples from women without gynecologic disorders and with leiomyoma. The cervical mucus samples from cervical adenocarcinomas showed low CA125 levels with extremely high CEA and/or CA19-9 levels. Therefore, analysis of the levels of these three tumor markers in the cervical mucus possibly helps in the diagnosis of cervical adenocarcinomas if CEA and/or CA19-9 show extremely high levels. When a ratio of (CEA + CA19-9)/CA125 was calculated, all women without gynecologic disorders and with leiomyoma showed a ratio less than 0.5, whereas ten of 11 cases of cervical adenocarcinomas had a ratio greater than or equal to 0.5. Only one case of microinvasive adenocarcinoma showed a ratio less than 0.5. Accordingly, the ratio greater than or equal to 0.5 strongly suggested an existence of cervical adenocarcinoma, although it included some cases of squamous cell carcinomas (four of 17 cases).

Adenocarcinoma↗
PubMed1988

[Effects of cadralazine on the respiration, circulation, kidney, autonomic nervous system, digestive system, blood and so on].

The general pharmacological effects of cadralazine and its major metabolite ISF 2405 were studied by comparing them with those of hydralazine. Cadralazine at 3.0 mg/kg, i.v., increased respiratory movement and heart rate and decreased blood pressure in cats. Cadralazine at 3.0 mg/kg, i.v., inhibited the hypertensive response induced by adrenaline, but showed little effect on the hypotensive response induced by acetylcholine in cats. Cadralazine and ISF 2405 at 10(-4) g/ml had negative chronotropic effects on isolated guinea-pig atria. The drug at 2.5 mg/kg, p.o., inhibited the passage of BaSO4 in the gastrointestinal tract in mice. The drug at 5.0 mg/kg, i.d. or more inhibited gastric secretion in rats. Cadralazine, except at higher doses, had little effect on spontaneous gastric motility and uterine spontaneous movement in rats. Cadralazine at 2.5 mg/kg, p.o., or more reduced or tended to reduce urine volume and urinary excretion of electrolytes. The drug showed little effect on coagulation and osmotic fragility in blood cell in rats nor on hemolysis and platelet aggregation in rabbits. ISF 2405, however, showed slight or moderate influence on hemolysis at concentrations as high as 0.01-1.0%. Cadralazine at 5.0 mg/kg, p.o. or more antagonized carrageenin-induced hind paw edema in rats. In conclusion, these effects of cadralazine were found to be qualitatively identical with those of hydralazine.

Animals↗
PubMed1988

Vitamin K-reversible hypoprothrombinemia in rats. I. Sex differences in the development of hypoprothrombinemia and the effects of beta-lactam antibiotics.

Male and female rats were fed an ordinary diet which contained about 500 ng vitamin K/g or a vitamin K-deficient diet containing less than 5 ng vitamin K/g. Hypoprothrombinemic changes such as prolongation of the prothrombin time (PT) and activated partial thromboplastin time (APTT) were detected in male rats within 4-6 days after feeding of the vitamin K deficient diet. Blood clotting factor VII and descarboxy prothrombin (PIVKA) levels changed rapidly, with maximum alteration at 2-4 days. Similar changes in factor VII and PIVKA levels were observed in female rats, but they appeared only after feeding of the K deficient diet for a long period. PT and APTT in female rats showed slight or no alteration even after 10 day feeding of the K-deficient diet. These results indicate that male rats are more susceptible to vitamin K deficiency than female rats. Administration of latamoxef led to a dose-dependent development of hypoprothrombinemia in vitamin K-deficient female rats. The hypoprothrombinemia in vitamin K-deficient female rats was caused by beta-lactam antibiotics with N-methyltetrazolethiol, thiadiazolethiol and methyl-thiadiazolethiol as the 3'-position substituent of the cephem nucleus.

Animals↗
PubMed1988

Vitamin K reversible hypoprothrombinemia in rats. II. Efficacy of vitamin K on latamoxef-induced coagulopathy in rats.

Feeding of a vitamin K-deficient diet caused the development of hypoprothrombinemic changes in rats such as prolongation of prothrombin time (PT) and activated partial thromboplastin time (APTT), decreases in plasma prothrombin and clotting factor VII levels, and an increase in the descarboxyprothrombin (PIVKA) level in both plasma and liver. Successive administrations of latamoxef (LMOX) to the vitamin K-deficient rats resulted in the further enhancement of these changes. After the development of hypoprothrombinemia with LMOX, a single subcutaneous injection of vitamin K1 normalized most of these abnormalities in blood coagulation parameters within 6 hr. When vitamin K was given at 200 micrograms/kg, PT, APTT and the plasma PIVKA level showed normal values for at least 8 days even when the animals were fed a vitamin K-deficient diet and treated with LMOX during the recovery period. The amount of vitamin K required to maintain most of the blood coagulation parameters in the normal range was about 3 micrograms/kg/day. The plasma level of vitamin K was higher than 0.3-0.5 ng/ml when the blood coagulation parameters were maintained in the normal range.

Animals↗