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Biomedical subjects

K Koike

Publications and source records attributed to K Koike.

At least 505 records · Page 28Linked to original sources
PubMed1992

[A case report of multiple-transfused aplastic anemia complicated by hemolysis and delayed neutrophil recovery after bone marrow transplantation].

The authors report an 18-year-old female who developed severe hemolytic reaction and delayed neutrophil recovery after bone marrow transplantation (BMT) for aplastic anemia from her HLA-identical sibling. She had received much transfusion (61 units of red blood cells including 4 units of fresh whole blood from her parents and 350 units of platelets) for 12 years before BMT. To prevent graft rejection, she received an intensified preparative regimen consisted of cyclophosphamide 200 mg/kg followed by 5 Gy total body irradiation and 5 Gy total lymphoid irradiation. Prophylaxis for GVHD was short term methotrexate and cyclosporin-A. Despite of the removal of the red cells from the marrow, marked hemolytic reaction caused by antibodies directed to rh" (E) and hr' (c) red cell antigens was observed when rh" (E) and hr' (c) positive donor erythroid began to recover. The recovery of neutrophils, especially the fraction of segmented cells was also delayed. Flow cytometry showed that the serially collected patient's sera reacted to neutrophils derived from both patient's blood on the 64th post-transplant day and the donor's blood. The reactivity was strongest in pre-BMT sera. We conclude that residual antibodies sensitized before BMT are a major cause of these hematological problems.

Adolescent↗
PubMed1992

[Radioaerosol inhalation and perfusion imaging studies in immediate postoperative phase after lobectomy].

In order to determine the changes in pulmonary ventilation-perfusion imaging after lobectomies, we examined 11 patients using radioaerosol inhalation and perfusion scintigraphies, before and after the operations. We employed 99mTc-labeled albumin aerosol generated by a jet nebulizer for the inhalation imaging, and 99mTc-labeled macroaggregated albumin for the perfusion imaging, respectively. Prior to the operations, there were no (major) defects of imagings on the lung fields. Immediately after the operations, however, we could not detect any abnormal findings on chest roentgenograms, we found detects of imagings on the lung fields in either inhalation or perfusion scintigraphy whose area were mismatching. It took more than 3 weeks for these defects of imagings to disappear. In conclusion, these findings suggest that postoperative hypoxemia might be occurred by these mismatchings.

Administration, Inhalation↗
PubMed1992

[Aortic dissection associated with Turner's syndrome].

We report two cases of Turner's syndrome who had had coarctation repair and who ultimately died from complications believed to be associated with Turner's stigmata. Case 1. The repair of coarctation of the aorta (Co/Ao) at age 5 was associated with the tear of the aortic wall and an Asc. Ao-Desc. Ao bypass together with the closure of the Ao proximal to the Co/Ao was performed. At age 10, she developed a dissecting aneurysm of the Asc. Ao seemingly unrelated to the previous surgery and the Asc. Ao was replaced by a prosthetic tube graft. Pathological diagnosis was cystic medionecrosis. The aortic valve was bicuspid. Subsequently, the patient showed progressive worsening of the aortic regurgitation. The aortic valve replacement at age 14 was complicated by significant bleeding and the patient died on the fifth postoperative day. Case 2. Co/Ao was repaired at age 8. During the operation, the aortic wall appeared to be thin and friable, and there was some tear of the posterior suture line which necessitated reanastomosis with resultant stenosis. At age 9, stenotic area was enlarged by an onlay-patch of a piece of woven Dacron arterial graft. There was gradual swelling of that area on routine x-ray examinations and an aortography at age 16 showed definite aneurysm formation. At age 18, she suddenly developed hemoptysis. Rupture of the aneurysm into the pleural cavity and the left lung was suspected. An emergency surgery to stop bleeding under hypothermic cardiopulmonary bypass was unsuccessful and the patient died in OR.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Dissection↗
PubMed1991

Interleukin-6 supports human megakaryocytic proliferation and differentiation in vitro.

The effect of interleukin-6 (IL-6) on cells of human megakaryocyte (MK) lineage from cord blood was explored. In semisolid colony assays containing human plasma, a greater number of both MK colonies and cells per colony was seen in the presence of IL-6 and IL-3 than in the presence of IL-3 alone. This stimulatory effect of IL-6, observed on both small and large MK colonies, was completely eliminated by the addition of anti-IL-6 antibody to the culture. IL-6 alone had no effect on MK colony formation. In the primary culture, MKs showed larger cell size and DNA content in the presence of both IL-3 and IL-6 than IL-3 alone. The replating experiments using immature MKs grown in the presence of IL-3 showed that IL-6 significantly augmented both cell size and DNA content. This effect was also neutralized by an anti-IL-6 antibody. IL-3 had no tangible effect on MK differentiation. Synergism between IL-6 and IL-3 on MK differentiation was not confirmed. These results suggest that IL-6 is a synergistic factor in the proliferation of MK progenitors and a direct effector of differentiation of immature MKs on in vitro human megakaryocytopoiesis.

Cell Differentiation↗
PubMed1991

Superoxide anion increases intracellular pH, intracellular free calcium, and arachidonate release in human amnion cells.

We determined the effects of superoxide anion, produced by addition of xanthine oxidase to hypoxanthine, on the intracellular pH (pHi) and intracellular free calcium concentration ([Ca2+]i) and release of arachidonate in human cultured amnion cells. Superoxide anion induced a prompt increase of pHi and subsequent increase of [Ca2+]i. The evoked pHi was inhibited by pretreatment with anion channel blockers but not affected by omission of extracellular Na+ or addition of amiloride. The increase of [Ca2+]i was inhibited significantly by the absence of extracellular calcium or by the addition of a calcium channel blocker, cobalt. NH4Cl, which can generally increase pHi, also increased [Ca2+]i of amnion cells. But the increase of [Ca2+]i induced by the NH4Cl was significantly less than that induced by the amount of superoxide anion causing a similar increase in pHi. These results show that superoxide anion, crossed through anion channel in membrane, increased [Ca2+]i at least partially via increase of pHi and that the calcium mobilization was dependent on both extracellular and intracellular sources. Superoxide anion induced the release of arachidonate in a dose-dependent manner and this induction was inhibited by omission of extracellular calcium. These data suggest that the release of arachidonate was dependent on the increase of [Ca2+]i. We also determined the viability of cells in the presence of superoxide anion by flow cytometry. Superoxide anion at the levels used in these experiments did not change the percentage of viable cells. These findings suggested that superoxide anion may regulate biological functions in amnion cells via pHi, [Ca2+]i mobilization, and the release of arachidonate without damaging the cells.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1991

HBx gene of hepatitis B virus induces liver cancer in transgenic mice.

The exact role of hepatitis B virus in the development of liver cancer is not known. The recent identification of a viral regulatory gene HBx suggests a possible direct involvement of the virus whereby the HBx protein, acting as a transcriptional transactivator of viral genes, may alter host gene expression and lead to the development of hepatocellular carcinoma. We have tested this possibility of placing the entire HBx gene under its own regulatory elements directly into the germline of mice. Transgenic animals harbouring this viral gene succumbed to progressive histopathological changes specifically in the liver, beginning with multifocal areas of altered hepatocytes, followed by the appearance of benign adenomas, and proceeding to the development of malignant carcinomas. Male mice developed disease and died much earlier than females. This transgenic animal model appears ideal for defining the molecular events that follow the expression of the viral HBx gene and are responsible for the development of liver cancer.

Animals↗
PubMed1991

Effects of nocturnal hyperprolactinemia on ovarian luteal function and galactorrhea.

To determine the effects of nocturnal hyperprolactinemia on luteal function and galactorrhea we studied six diurnal normoprolactinemic women with regular menstrual cycles. The diurnal serum levels of prolactin (PRL), luteinizing hormone (LH) and progesterone (Prog) and the nocturnal PRL levels at 1 h intervals were determined throughout the first menstrual cycle. Four of the women were nocturnally normoprolactinemic and two showed nocturnal hyperprolactinemia and low luteal progesterone values. In the second menstrual cycle, they were given metoclopramide (10 mg) at midnight before sleep every day, and their serum levels of PRL, LH and Prog were determined by the same protocol as in the first cycle. During treatment with metoclopramide, all the women showed nocturnal hyperprolactinemia, but their diurnal PRL levels remained within the normal range. Low luteal Prog values were observed in all of them and the peak LH levels decreased in all four nocturnally normoprolactinemic women. They had galactorrhea but neither of the nocturnally hyperprolactinemic women had galactorrhea. These results suggest that nocturnal hyperprolactinemia is a cause of luteal insufficiency and galactorrhea.

Adult↗
PubMed1991

Specific uptake of asialofetuin-tacked liposomes encapsulating interferon-gamma by human hepatoma cells and its inhibitory effect on hepatitis B virus replication.

Asialofetuin-tacked liposomes (AF-liposomes) encapsulating interferon (IFN)-gamma were bound and internalized into a human hepatoma cell line, HepG2 cells, selectively through asialoglycoprotein receptor, but not non-tacked liposomes (N-liposomes). AF-liposomal IFN-gamma was more effective for inhibition of viral DNA replication in hepatitis B virus (HBV)-producing clone from HepG2 cells transfected with HBV-DNA than N-liposomal IFN-gamma. AF-liposomes may increase the therapeutic potential of IFN-gamma through asialoglycoprotein receptor in treating HBV-infected hepatocytes.

Asialoglycoprotein Receptor↗
PubMed1991

Effects of aging on alpha 2-adrenoceptor mechanisms in isolated guinea-pig tracheal preparations.

The effects of aging on alpha 2-adrenoceptor mechanisms in tracheal preparations isolated from 3-, 6-, 10-, 40- and 100-week-old guinea-pigs were studied. The potency of noradrenaline decreased with age. The specific binding of [3H]p-aminoclonidine to microsomal fractions prepared from tracheal smooth muscles from 6- and 40-week-old guinea-pigs was analysed by Scatchard analysis. The capacity of maximum binding sites of [3H]p-aminoclonidine was greater in the preparations from 40-week-old guinea-pigs than in 6-week-old animals, whereas the dissociation constant did not change with age. The amount of prostaglandin F2 alpha released by noradrenaline and the contractile response to prostaglandin F2 alpha decreased with age. These results suggest that an age-related decrease in the potency of noradrenaline is due to the decrease in the amount of excitable prostaglandin F2 alpha released by noradrenaline and in the contractile response to prostaglandin F2 alpha, but not to a change in the total number of alpha 2-adrenoceptors or in the dissociation constant of a drug from alpha 2-adrenoceptors. Extraneuronal uptake also plays a role in the response to noradrenaline in the tracheal preparations from older guinea-pigs.

Adrenergic alpha-Agonists↗
PubMed1991

Interferon therapy for non-A, non-B chronic hepatitis.

We report the results of our study on 8-week consecutive interferon (IFN) treatment for chronic non-A, non-B hepatitis. In the 6 MIU/day group, most cases had continuously normalized alanine-aminotransferase (ALT) levels even after IFN treatment was discontinued. In responders whose ALT levels remained normal, not only the degree of inflammation, as seen from HAI scores, but also liver histopathological features were improved. Moreover, antibody to hepatitis C virus (anti-HCV) titer in responders was continuously decreased. Antiviral effects of IFN were observed by detection of HCV-RNA using the PCR technique. HCV-RNA became negative with IFN treatment, however, in some patients who relapsed after discontinuation of IFN treatment, re-elevation of ALT levels was usually preceded by re-appearance of HCV-RNA.

Alanine Transaminase↗
PubMed1991

Short-term treatment with 17-beta estradiol enhances spontaneous [3H] dopamine release from cultured rat tuberoinfundibular neurons.

The effects of 17-beta estradiol (E2) on spontaneous [3H] dopamine ([3H]DA) release was investigated using primary cultured cells from the tuberoinfundibular region of rat hypothalamus, which includes DA neurons. [3H] DA uptake by the neurons in the presence of E2 at 10(-8) mol/l was similar to that by control cells. Pretreatment with E2 at 10(-9) mol/l or more resulted in dose-dependent increase in spontaneous [3H] DA release from the cultured hypothalamic cells. The spontaneous [3H] DA release reached almost a plateau on pretreatment with E2 at 10(-9) mol/l for 6 hours. Pretreatment with 1 nM E2 also enhanced DA release induced by 10 microM ionophore A23187. These results indicate that estrogen stimulates tuberoinfundibular DA neuronal activity.

Animals↗
PubMed1991

The interferon family stimulates the secretions of prolactin and interleukin-6 by the pituitary gland in vitro.

The effects of interferon-alpha, interferon-beta 1 and interferon-gamma on the secretions of prolactin (PRL) and interleukin-6 by primary cultured rat anterior pituitary cells were examined. These three interferons caused dose-dependent increases in PRL secretion within 30 min, and dose-dependent stimulation of interleukin-6 were weaker than the effects of interleukin-1 and tumor necrosis factor-alpha. These results suggest that interferons regulate PRL secretion from the pituitary gland, and that there may be a pathway in which interferons stimulate PRL secretion through interleukin-6 release.

Analysis of Variance↗
PubMed1991

Propylbenzilylcholine mustard-sensitive and -resistant muscarinic receptors in cardiac muscle.

1. A left atrium of guinea pig driven electrically was used as a test organ containing M2-cholinoceptors. 2. Concentration-response curves of carbachol and butyltrimethylammonium, muscarinic full agonists, were progressively inhibited by 10 and 30 min treatments of the atrium with propylbenzilylcholine mustard (PrBCM; 10(-6) M). The 50 min treatment with PrBCM had no further significant inhibitory effect on their curves. 3. The 30 min treatment of the atrium with PrBCM completely inhibited the concentration-response curve of pilocarpine, a partial agonist. In the atrium after the 30 min treatment with PrBCM, pilocarpine shifted the concentration-response curves of the full agonists, suggesting a competitive antagonism. 4. These results suggest an existence of two subtypes of M2-receptors; PrBCM-sensitive and -resistant ones, and that the full agonists inhibit the twitch through an interaction of both the receptors, while the partial agonist produce inhibition through an activation of PrBCM-sensitive ones.

Animals↗
PubMed1991

Effects of ageing on nicotine-induced contraction and substance P-like materials release in guinea-pig bronchus.

1. Effects of ageing on nicotine-induced contraction and release of substance P-like materials in the bronchial preparations from guinea-pigs of different ages were studied. 2. The pD2 value (potency) of nicotine decreased with age from 10 to 100 weeks. The pD2 value of substance P did not change with age suggesting that substance P receptor mechanisms do not alter with age. 3. The amount of substance P-like materials released by nicotine (10(-4) M) decreased with age from 10 to 100 weeks, supporting our previous findings that nicotine contracts the guinea-pig bronchus through the release of substance P-like materials. 4. These results suggest that the age-related decrease in the pD2 value (potency) of nicotine is due to the reduction in the amount of substance P-like materials released by nicotine.

Aging↗
PubMed1991

Effect of ageing on response to nicotine in rabbit bronchial preparation.

1. Effect of ageing on the response to nicotine was tested in the bronchial muscle preparations from 5, 13, 100 and 125 week-old rabbits. The pD2 value (potency) of nicotine significantly increased in the preparation from the 125 week-old rabbits. No age-related change was found in the pD2 value of carbamylcholine or pA2 value of atropine. 2. No age-related change in characteristics of nicotine receptors. Choline acetyltransferase activity, the amount of acetylcholine released by nicotine and acetylcholineesterase activity decreased in the preparations from the 125 week-old rabbits. 3. Decrease in the pD2 value of nicotine in the preparation from the older rabbit is due to a decline in choline acetyltransferase activity followed by a reduction in the acetylcholine released, and not to a change in characteristics of nicotine receptors. 4. These results also suggest that enzymes may be influenced more easily with age than drug receptors.

Acetylcholine↗
PubMed1991

Characterization of muscarine receptors in rabbit ciliary body smooth muscle using propylbenzilylcholine mustard.

1. A piece of rabbit ciliary body was mounted in organ bath and used as a test organ containing muscarine receptors. 2. A concentration response curve of carbachol was completely inhibited by a 50 min treatment of the smooth muscle preparation with propylbenzilylcholine mustard(PrBCM; 10(-6) M). This treatment was reported to block PrBCM-sensitive muscarine receptors in intestinal smooth muscle completely. 3. It is suggested that an existance of only PrBCM-sensitive muscarinic receptors, though there are two subtypes of muscarine receptors; PrBCM-sensitive and -resistant ones in intestinal smooth muscles.

Animals↗