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Biomedical subjects

K Koike

Publications and source records attributed to K Koike.

At least 613 records · Page 34Linked to original sources
PubMed1989

Distinguishing between anomalous origin of the left coronary artery from the pulmonary trunk and dilated cardiomyopathy: role of echocardiographic measurement of the right coronary artery diameter.

Patients with anomalous origin of the left coronary artery from the pulmonary trunk usually have a large right coronary artery. This study examines the diagnostic value of measuring the diameter of the right coronary artery by echocardiography in distinguishing between this lesion and other causes of dilated cardiomyopathy. The diameter of the right coronary artery and the right coronary artery/aorta ratio were measured in the parasternal short axis view in 40 controls, 11 patients with dilated cardiomyopathy, and 10 with anomalous origin of the left coronary artery from the pulmonary trunk. In the controls, the diameter of the right coronary artery increased with age, but the right coronary artery/aorta ratio remained constant. In the control group the 95% upper limits of prediction for right coronary artery diameter were 1.6 mm for one month of age, 1.8 mm for three months, 2.0 mm for one year, 2.2 mm for two years, 2.4 mm for three years, 2.6 mm for four years, 2.7 mm for six years, 3.0 mm for eight years, and 3.2 mm for 10 years; and for right coronary/aorta ratios the limits were 0.17 for one month to one year, 0.18 for one to six years, 0.19 for six to 10 years, and 0.20 for more than 10 years. All patients with dilated cardiomyopathy had normal right coronary artery diameters and right coronary artery/aorta ratios (0.10-0.13). Those patients with anomalous origin of the left coronary artery from the pulmonary trunk had larger than normal right coronary artery diameter and a significant increase in the right coronary artery/aorta ratio (0.21-0.29). The presence of an anomalous left coronary artery was likely if the diameter of the right coronary artery or the right coronary artery/aorta ratio was larger than the normal 95% limits of prediction.

Cardiomyopathy, Dilated↗
PubMed1989

Involvement of extracellular calcium and arachidonate in [3H] dopamine release from rat tuberoinfundibular neurons.

The mechanism of [3H]dopamine [( 3H]DA) release was investigated using primary cultures of dispersed cells from the rat tuberoinfundibular region, which contains tyrosine hydroxylase (TH)-like immunoreactive neurons. The calcium ionophore A23187 at 10 nM and above caused a significant and dose-dependent increase in [3H]DA release. In the presence of 50 microM A23187, [3H]DA release was detectable within 30 s and reached a plateau in 15 min. The induction of [3H]DA release by 50 microM A23187 was abolished by lowering the extracellular calcium concentration with 2 mM EDTA. Maitotoxin, another calcium-channel activator, also increased [3H]DA release at a concentration of 50 ng/ml. Exogenous additions of 100 mIU/ml phospholipase A2 and 10 microM arachidonate caused significant release of [3H]DA. Furthermore, A23187 stimulated [3H]arachidonate release from tuberoinfundibular dopaminergic (TIDA) neurons in a dose- and time-dependent manner. These results suggest that extracellular calcium and arachidonate are involved in the process of [3H]DA release from rat TIDA neurons.

Animals↗
PubMed1989

Effects of a new positive inotropic agent with a vasodilatory action, 5-methyl-6-(4-pyridyl)-2H-1,4-thiazin-3(4H)-one (ZSY-27), on calcium-movement and mechanical response in rabbit thoracic aorta.

The effects of 5-methyl-6-(4-pyridyl)-2H-1,4-thiazin-3(4H)-one (ZSY-27), a positive inotropic agent with a vasodilatory action, on a concentration-response curve of CaCl2 in the KCl-depolarized rabbit thoracic aorta and Ca-uptake by the microsomal fraction from the rabbit artery were tested. ZSY-27 (10(-5) - 10(-4) M) inhibited noncompetitively a concentration-response curve of CaCl2 in the KCl-depolarized preparation. Furthermore, ZSY-27 (10(-5) M) stimulated significantly Ca-uptake by the microsomal fraction in the presence of oxalate, as an indicator for Ca-uptake by the internal membrane, in every incubation time. However, it inhibited significantly that in the absence of oxalate, as an indicator for Ca-uptake by the plasma membrane-derived vesicle, after 6 min of incubation time. These results suggest that ZSY-27 stimulates Ca-uptake by the internal membranes and inhibits Ca-uptake by the plasma membrane-derived vesicles. Therefore, these effects of ZSY-27 are considered to be related to relaxation of vascular smooth muscle.

Animals↗
PubMed1989

Saponins from Chinese folk medicine, "zhu jie xiang fu," Anemone raddeana REGEL.

From the Chinese folk medicine "Zhu jie xian fu" (roots of Anemone raddeana REGEL, Ranunculaceae), two new oleanane-type glycosides, named raddeanosides R8 (1) and R9 (2), were isolated. The structures of 1 and 2 were determined as 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-beta-D-glucopyranosyl- (1----2)-alpha-L-arabinopyranosyl oleanolic acid 28-O-alpha-L-rhamnopyranosyl-(1----4)-O-beta-D-glucopyranosyl-(1----6)-b eta-D- glucopyranoside and 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-beta-D-glucopyranosyl-(1----2)-al pha-L- arabinopyranosyl 27-hydroxyoleanolic acid 28-O-alpha-L-rhamnopyranosyl-(1----4)-O-beta-D-glucopyranosyl-(1----6)-b eta-D- glucopyranoside, respectively.

Drugs, Chinese Herbal↗
PubMed1989

Collapse and reexpansion of lungs increase microvascular permeability in sheep.

The pathogenesis of reexpansion pulmonary edema has not been well studied. We tested the hypothesis that both long term collapse and subsequent reexpansion of the lungs cause reexpansion pulmonary edema by increasing pulmonary microvascular permeability. We investigated lymph dynamics in 15 experiments on collapsed lung and 10 experiments after lung reexpansion in 14 unanesthetized sheep with chronic lymph fistulas. We found that 24-hr left lung collapse increased lymph flow through the caudal mediastinal lymph node from the baseline of 1.71 +/- 0.97 (mean +/- S.D.) g/15 min to 2.01 +/- 0.99 g/15 min, although 2-hr collapse did not affect lymph flow. The L/P ratio did not fall below baseline in either experiment. Pulmonary arterial pressure increased by only about 6 cmH2O both in 2-hr and 24-hr collapse. Reexpansion after 24-hr lung collapse also increased lymph flow from the baseline of 1.64 +/- 0.52 g/15 min to 3.20 +/- 0.79 g/15 min during the first 2 hr after reexpansion. The lymph-to-plasma protein concentration ratio did not fall below the baseline. Reexpansion after 2-hr collapse did not affect these variables. We conclude that both long term lung collapse and subsequent reexpansion lead to reexpansion pulmonary edema by increasing pulmonary microvascular permeability.

Animals↗
PubMed1989

[Respiratory regulations of pulmonary vagal nerves under hypercapnic conditions; effects of J-receptor].

We studied ventilatory responses under hypercapnic condition in 9 lightly anesthetized dogs, using a vagal nerve cooling technique. One side of the cervical vagosympathetic trunks of dogs were previously severed, and a copper cooler was attached to the other side. When the cervical nerve was cooled below 7 degrees C, the Hering-Breuer inflation reflex ceased. We found that when the vagal nerve was not cooled or cooled to 7 degrees C, the respiratory frequency increased significantly in relation to hypercapnic gas inhalation. However, the increment of respiratory frequency was reduced by bilateral cervical vagotomy. We concluded that the J-receptor is responsible for the increase in respiratory frequency under hypercapnic gas inhalation.

Animals↗
PubMed1989

Activated N-ras gene was found in human hepatoma tissue but only in a small fraction of the tumor cells.

Activated N-ras gene was isolated from human hepatoma tissue by DNA transfection assay coupled with the neomycin selection method and molecular cloning and a point mutation in the codon 61 (CAA----AAA) was noted. However, examination of the proportion of the mutated N-ras gene in the tumor part by molecular cloning and by hybridization using synthetic oligonucleotide probes indicated that the mutated gene occurred with very low frequency. The activated N-ras gene appears located only in a small fraction of the tumor cells. The experimental data indicate activation of this gene as possibly not the major cause of carcinoma, but rather a manifestation of tumor heterogeneity.

Animals↗
PubMed1989

[Childhood Ki-1 lymphoma complicated with multiple bone destruction].

A 4-year-old girl was admitted because of fever, swelling of left chest wall and left axillary lymphadenopathy. Chest XP revealed left pleural effusion. Ga-scintigram showed multiple accumulation in skull, left ribs and iliac bone. A diagnosis of childhood Ki-1 lymphoma was made from the pathological findings of tumor in the skull. Immunopathological study revealed that the neoplastic cells were CD8 positive (suppressor phenotype).

Antigens, CD↗
PubMed1989

[A case of hemangioma of the heart].

A-74-year old woman who had suffered from anterior chest pain and palpitation was admitted to our hospital. The chest X-ray photograph showed that the heart was enlarged mildly. We found that the tumor lay in the mediastinum by the echocardiograph and was enhanced at the aortic phase of the radioisotope angiography. In order to obtain the histological specimen, she underwent exploratory thoracotomy. The tumor was diagnosed as a cavernous hemangioma. She has been asymptomatic over 1-year period. The RI angiography seemed to be useful to diagnose the hemangioma of the heart.

Aged↗
PubMed1989

[Estimation of the filtration variables in the rat lung].

The filtration variables, filtration coefficient (K), perimicrovascular pressure (Ppmv) and reflection coefficient (sigma) were estimated independently in previous reports using the Starling Equation or the micropuncture method. We estimated these variables simultaneously. We measured filtration rate by a gravimetric method in isolated rat lung lobes in zone 1 conditions (alveolar pressure = 20 cmH2O) at two vascular pressures, Pvasc = 15 or 8 cmH2O and perfused the lobes with plasma containing a low or high concentration of protein. By extrapolating the log of the rate of weight gain to time = 0, we obtain the initial filtration rate. Assuming that protein filtered into perimicrovascular space only by convection, we substituted into the Starling Equation as follows: Q = K[(Pmv-Ppmv)-sigma 2 pi mv], where Pmv and pi mv are hydrostatic and plasma protein osmotic pressures in microvascular space. pi mv was estimated by Yamada's equation. We obtained K = 26.3 +/- 8.7 mg/(min.cmH2O.g), PPMV = 6.2 +/- 0.7 cmH2O, sigma = 0.46 +/- 0.07. The chief advantages of this method are that it does not require a separate estimation of isogravimetric pressure or a direct measurement of interstitial pressure, and that all variables are obtained simultaneously.

Animals↗
PubMed1989

[Induction of pulmonary edema in rat with pulmonary artery air embolization and inhibitory effects of dilazep hydrochloride].

Inducing pulmonary edema in rat, air bubbles the diameter of which was about 0.3 mm were continuously infused into the right atrium through a catheter at the rate of 2.8 ml/kg/hr during 0.5, 1 and 2 hours, under controlled ventilation (tidal volume of 9 ml/kg and respiratory rate of 80/min) with 1% halothane in room air. Saline or Dilazep hydrochloride solution was simultaneously infused into the right atrium via another catheter. Pulmonary edema was evaluated by the measurement of the ratio of extravascular water weight of lung (g) to blood-free dry lung weight (g) (EVWW) using the gravimetric method and with histologic studies using the rapid freezing method. In control rats, which were sacrificed immediately after induction of anesthesia, the EVWW was 3.114 +/- 0.121 g/g blood-free dry lung (mean +/- 1 S.D. n = 8). In baseline experiments (2 hours ventilation and saline infusion without air embolization), the EVWW was 3.291 +/- 0.081 (n = 4). In air embolization groups with 2 hours saline infusion, EVWW were 3.756 +/- 0.170 (n = 4), 3.722 +/- 0.170 (n = 4) and 3.731 +/- 0.245 (n = 5) in 0.5, 1 and 2 hours infusion groups, respectively. Regardless of emboli infusion time perivascular cuffs and peribronchial cuffs were revealed in the 2 hour saline infusion groups. In the experiment in which the animals were sacrificed immediately after one hour infusion of air bubbles, there was no evidence of pulmonary edema and the EVWW of 3.060 +/- 0.092 (n = 4) in this group control and baseline were not significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Possible involvement of vascular endothelium-derived relaxing factor induced by platelet-activating factor (PAF) on human pulmonary artery after contraction in vitro].

We studied the effects of platelet-activating factor (PAF) on human pulmonary vascular smooth muscle in vitro. 10(-6) M PAF elicited slight contractions in 2 of 7 endothelium-denuded arterial strips, but did not elicit distinct contractions or relaxations in the other strips. After incubation with PAF at 10(-7) M, the contractions of pulmonary vascular smooth muscle induced by histamine and prostaglandin F2 alpha were significantly decreased. Preincubation of 10(-3) M indomethacin did not affect the inhibitory effects of PAF, but these disappeared with removal of endothelium. These results suggest that the inhibitory effects of PAF on human pulmonary vascular smooth muscle contractions may appear not through the cyclooxygenase products but the endothelium-derived relaxing factor.

Female↗
PubMed1989

Oncogenic potential of hepatitis B virus.

The function of the X gene was clarified by examination of the transient production of hepatitis B virus (HBV) particles by transfected recombinant HBV DNA (pHBV-3 DNA) and its frameshift mutant (delta X) of the X open reading frame into hepatocellular carcinoma HuH-7 and HepG2 cells. No reduction of viral mRNAs was observed in the HuH-7 cells by the delta X mutant, whereas mRNAs underwent marked reduction in HepG2 cells. No reduction in core particle production was observed in HuH-7 cells, but in HepG2 cells reduction was considerable. To clarify the significance of the delta X mutation in the trans-acting function of the X gene in hepatoma cells, the chloramphenicol acetyl/transferase (CAT) assay was conducted. Transfection of plasmid pHBV-3 into HepG2 cells increased CAT activity of pSV2-CAT, while the delta X mutation clearly showed no stimulation of activity. On the other hand, in the HuH-7 cells, pHBV-3 exhibited no such stimulation. The trans-acting function of the X gene product in two different hepatoma cells was clearly shown to differ. Furthermore, transfection of X gene expression plasmid pKSV-HBx into mouse NIH3T3 cells increased the CAT activity of pSV2-CAT. Trans-activation was still detectable even following deletion of enhancer sequences in the pSV2CAT. The oncogenic potential of HBV is discussed with special attention to the X gene product, which may be able to activate a cellular transcription factor at the viral and cellular promotor sequences in the cells.

Animals↗
PubMed1989

[Effect of a protein-bound polysaccharide, PSK, on human hemopoietic progenitors].

Using in vitro clonal culture assays, we investigated the effects of PSK, a protein-bound polysaccharide derived from the cultured mycelium of CM101, Coriolus versicolor (Fr.) Quél in Basidiomycetes, on human hemopoietic progenitors. PSK alone did not stimulate colony formation by human bone marrow progenitors. Although 1-100 micrograms/ml of PSK had no effects on colony formation stimulated by erythropoietin and medium conditioned by phytohemagglutinin-stimulated leukocytes, more than 1 mg/ml of PSK inhibited all types of colony formation. In contrast, medium conditioned by PSK-stimulated leukocytes significantly stimulated formation of various types of colonies including erythroid bursts, granulocyte and/or macrophage colonies, eosinophil colonies, megakaryocyte colonies and mixed hemopoietic colonies. It is speculated that administration of the optimal dose of PSK can reduce the hematological suppression of antitumor drugs.

Cell Division↗