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Biomedical subjects

K Koike

Publications and source records attributed to K Koike.

At least 577 records · Page 32Linked to original sources
PubMed1990

Evidence for release of prostaglandin F2 alpha in contractile response of guinea pig trachea to norepinephrine.

The concentration (10(-8)-10(-5) M)-dependent contractile response of norepinephrine was completely inhibited by cyclooxygenase inhibitors but not by a thromboxane synthetase inhibitor. The amount of prostaglandin F2 alpha was significantly increased in the presence of norepinephrine (10(-5) M). Norepinephrine increased the amount of prostaglandin D2, although not significantly. The norepinephrine-evoked prostaglandin release was inhibited by tolazoline (3 x 10(-5) M). These results suggest that norepinephrine evoked the release of prostaglandins, mainly prostaglandin F2 alpha to induce the contraction of the guinea pig trachea.

Animals↗
PubMed1990

5-Hydroxyeicosatetraenoic acid and phorbol ester stimulate prolactin release from rat anterior pituitary cells by different mechanisms.

The relationship between 5-hydroxyeicosatetraenoic acid (5-HETE) and calcium-activated, phospholipid-dependent protein kinase (protein kinase C) in prolactin (PRL) release was investigated in rat anterior pituitary cells. Arachidonic acid or 5-HETE, a 5-lipoxygenase metabolite of arachidonic acid, is known to cause a significant concentration-dependent increase in PRL release. Phorbol 12-myristate 13-acetate (PMA) and dioctanoyglycerol (diC8) have also been known to stimulate PRL release from pituitary cells, so we showed that these PRL releases were correlated with the activation of protein kinase C, that is, they induced dose-dependent translocation of protein kinase C from the cytosol to the membrane. Arachidonic acid, however, did not cause a significant change in the distribution of protein kinase C. We also showed that the PRL release induced by arachidonic acid and that induced by 5-HETE were additional to that by 100 nM PMA. Thus we suggested that the signals for the stimulation of PRL release sent by arachidonic acid and 5-HETE would be different from the signal sent through protein kinase C by PMA.

Animals↗
PubMed1990

Interleukin 1 beta and tumour necrosis factor alpha stimulate the release of gonadotropin-releasing hormone and interleukin 6 by primary cultured rat hypothalamic cells.

The abilities of recombinant human interleukin 1 beta and tumour necrosis factor alpha to induce release of GnRH and interleukin 6 from primary culture of rat hypothalamic cells were examined. The effect of estradiol on the release of interleukin 6 by these cells was also tested. Both interleukin 1 beta and tumour necrosis factor alpha caused significant stimulation of GnRH secretion from the hypothalamic cells within 5 min. The hypothalamic cells secreted interleukin 6 spontaneously, and their secretion over 24 h was stimulated dose-dependently by interleukin 1 beta, tumour necrosis factor alpha and estradiol. These results suggest that interleukin 1 beta and tumour necrosis factor alpha stimulate the secretions of GnRH and interleukin 6 in the hypothalamus, and that these cytokines may be involved in the mechanism of GnRH secretion in the hypothalamus.

Animals↗
PubMed1990

A new method for estimating filtration variables in isolated zone 1 rat lung.

The filtration variables, K (filtration coefficient), Ppmv (perimicrovascular pressure) and sigma (reflection coefficient), were estimated independently in previous reports using the Starling equation or the micropuncture method. We used matrix algebra to estimate these variables simultaneously. We measured filtration rate (Q) by a gravimetric method in isolated rat lung lobes in zone 1 conditions (alveolar pressure = 20 cmH2O) at two vascular pressures, Pvasc = 15 or 18 cm H2O and perfused the lobes with plasma containing a low or a high concentration of protein. By extrapolating the log of the rate of weight gain to t = 0, we obtain the initial filtration rate before any of the pressure variables (microvascular and perimicrovascular hydrostatic pressures) in the Starling equation changed. Assuming that protein filtered into perimicrovascular space only by convection, we substituted it into the Starling equation as follows: Q = K [(Pmv -- Ppmv) -- sigma 2 (IImv)], where Pmv and IImv are microvascular and perimicrovascular plasma protein osmotic pressures. IImv was estimated by Yamada's equation (Yamada et al. 1985). For the matrix algebra, we used three values, we omitted the value for the high protein, low vascular pressure experiment. We obtained K = 26.3 [mg/(min x cmH2O x g wet weight)], Ppmv = 6.2 cmH2O and sigma = 0.46. These values agree with values from previous reports. Since these 3 filtration variables are interrelated, this new method for simultaneous measurement is more accurate than independent measurements are. The chief advantage of this method is that it does not require a separate estimate of isogravimetric pressure or a direct measurement of interstitial pressure, and all variables are obtained simultaneously.

Algorithms↗
PubMed1990

Biochemical characterization of the membrane-associated phosphorylating proteins involved in the anti-proliferative effect of human recombinant interferon-alpha 2a (rIFN-alpha 2a) in Daudi cells.

The anti-proliferative effect of interferons (IFNs) was investigated, focusing on the physiological activities of membrane-associated proteins involved in the progress of cell proliferation. In preliminary screening of the inhibitory effect of IFNs against the cell growth of various human hematopoietic tumor cells, Daudi cell was the most sensitive to rIFN-alpha 2a. SDS-PAGE followed by autoradiography detected that treatment of Daudi cells with rIFN-alpha 2a significantly reduced phosphorylation of the membrane-associated Mr 98,000 and 70,000 polypeptides. To determine the physiological significance of these phosphorylating polypeptides in mediation of the IFN effects, they were purified from Daudi cells. It was found that the molecular weight of the purified polypeptides was approximately 330,000 and it (designated 330-kDa protein) was consist of two distinct subunits [alpha-subunit (Mr 98,000) and beta-subunit (Mr 70,000)]. The biochemical properties, such as subunit structure, subunit phosphorylation, requirements for phosphorylating activity and protease sensitivity of the 330-kDa protein were similar to those reported for Na+, K(+)-ATPase. Evidence provided here suggests that the anti-proliferative action of IFNs may, at least in part, be implicated in the IFN-induced physiological impairment of the membrane-associated 330-kDa protein.

Cell Division↗
PubMed1990

Coronary angiography of pulmonary atresia, hypoplastic right ventricle, and ventriculocoronary communications.

A retrospective study was undertaken to determine the spectrum of angiographic abnormalities of the coronary arteries in infants and children with pulmonary atresia, hypoplastic right ventricle, and right ventriculocoronary arterial communications. Twenty-nine patients with 67 angiographic examinations were reviewed; findings in seven patients were compared with those at autopsy. Twenty-seven (93%) of 29 patients had caliber abnormalities of the involved coronary arteries, including obstructive lesions in 20 (69%) of 29 and segmental dilatation in 16 (55%) of 29. Nine patients had interruption of the anterior descending artery and one had absent connection between the coronary arteries and the aorta. A single coronary artery was found in four of 29 patients. There was excellent correlation between clinical angiography and autopsy findings in seven patients. This study confirms the ability of high-quality clinical angiography to show significant abnormalities of the coronary arteries in infants and children with pulmonary atresia and ventriculocoronary communications.

Child↗
PubMed1990

Stereoselective total synthesis of wheat flour ceramide dihexoside.

A plant glycosphingolipid, O-(beta-D-mannopyranosyl)-(1----4)-O-(beta-D-glucopyranosyl)-(1----1)-(2 S,3S,4R)-4-hydroxy-N-tetracosanoylsphinganine 1, and the stereoisomer, O-(alpha-D-mannopyranosyl)-(1----4)-O-(beta-d-glucopyranosyl)-(1----1)-( 2S,3S,4R)-4-hydroxy-N-tetracosanoylsphinganine 6, were synthesized in a stereo- and regio-controlled way.

Carbohydrate Sequence↗
PubMed1990

[Mixed type total anomalous pulmonary venous connection with the left upper pulmonary vein draining into the innominate vein and the other pulmonary veins into the coronary sinus--surgical correction in 2 infants].

Surgical repair of the mixed type total anomalous pulmonary venous connection (TAPVC) in infancy is known to be difficult. In this report, experience of two infants with the mixed type TAPVC with the left upper pulmonary vein (PV) draining into the innominate vein and the other PVs into the coronary sinus (IIa + Ia (left upper PV) type TAPVC) is presented. In such cases, it has been said that the left upper PV should be left uncorrected, but we anastomosed the left upper PV, that was thin and fragile, to the left atrium and corrected all the other anomalous PVs. The results were satisfactory. Recently, Extra-Corporeal circulation, microsurgery, and other techniques have significantly progressed, so we consider that the anastomosis is possible in most infants with IIa + Ia (left upper PV) type TAPVC. In the future, careful clinical follow-up and repeat catheterizations should be done, and we'd like to examine the long term patency of the left upper PV.

Anastomosis, Surgical↗
PubMed1990

[Correlation between slopes of pulmonary blood flow-driving pressure curve and routine pulmonary function].

In 91 preoperative cases of lung cancer, an attempt was made to correlate the slopes of pulmonary blood flow-driving pressure curve (delta DP/delta CI), as constructed from unilateral pulmonary arterial occlusion (UPAO) test values and pulmonary blood flow fraction values as measured by scintigraphy, with total pulmonary vascular resistance index (TPVRI) and pulmonary vascular resistance index (PVRI) and routine pulmonary function. FVC and FEV per unit body surface (BSA) were found to correlate, to same degree, with delta DP/delta CI, TPVRI and PVRI (p less than 0.05). delta DP/delta CI correlated significantly with FRC/BSA, whereas TPVRI and PVRI did not. 3) The inverse of the cardiac index (1/cardiac index) was shown to significantly correlate with TPVRI and PVRI (r = 0.64, 0.48), but poorly with delta DP/delta CI (r = 0.32). These results suggest that delta DP/delta CI might possibly provide a more useful quantitative index for the pulmonary vascular bed than TPVRI and PVRI.

Adult↗
PubMed1990

[Activated pulmonary intravascular macrophages increase pulmonary microvascular permeability in sheep].

Pulmonary intravascular macrophages (PIMs) reside in the alveolar capillaries of sheep lung. However, the role of PIMs activation in the mechanism of increasing pulmonary microvascular permeability is not clear. We determined, using awake sheep with chronic lung lymph fistulas, the effects of intraarterial infusion of latex beads emulsion (1 microns in diameter) on lung lymph-dynamics. Sheep were divided into 3 groups; control, low dose latex and high dose latex groups. In control group, their lymph-dynamics were stable during the experimental period. In low dose latex group (5.46 x 10(9) beads/kg), lung lymph flow increased during the infusion period, but lung lymph protein clearance did not change. In high dose latex group (5.46 x 10(10) beads/kg), lung lymph flow began to increase during the infusion period and remained high, and lung lymph protein clearance increased significantly during and after the infusion of latex beads emulsion. The latex beads mainly distributed to lungs, and 70% of the beads were caught by PIMs in their phagosomes. These findings suggest that the activation of PIMs through their phagocytic uptake of circulating microparticles increases pulmonary microvascular permeability.

Animals↗
PubMed1990

[Pleuropneumonectomy with thymectomy for invasive thymoma with pleural disseminations--a case report].

A case of invasive thymoma with pleural disseminations, treated with pleuropneumonectomy and thymectomy , is presented. A 30-year-old woman was admitted with abnormal shadows in left lung field and mediastinum. On chest CT examination, the tumor shadows were located anterior mediastinum and left chest wall. Thymoma with pleural disseminations was the most likely consideration by the needle biopsy specimen of the tumor under left chest wall. Preoperative radiotherapy for anterior mediastinum mass was effective. Pleuropneumonectomy and thymectomy combined with partial resections of intercostal muscles and diaphragm were performed. Histologically, the tumor was arranged in lobular structure, composed of epithelial cells, with poorly infiltration of lymphocytes, and invaded into intercostal muscles or lung. Postoperative radiotherapy for mediastinum and left chest wall was added. Tumors may be removed completely by pan-pleuropneumonectomy and thymectomy for invasive thymoma with pleural disseminations.

Adult↗
PubMed1990

[Subtotal cor triatrium with left partial anomalous pulmonary venous connection--successful correction in an infant].

This report concerns a 10-month-old infant with subtotal cor triatrium associated with left sided partial anomalous pulmonary venous connection to the innominate vein. In the operation, we found that the fossa ovalis existed between the right atrium and the accessory atrial chamber. We performed a radical operation which consisted of a resection of the intra-left-atrial diaphragma and a anastomosis of the vertical vein to the left atrium. His postoperative course was uneventful, and the result was satisfactory. We have presented and reviewed our case, and then discussed the embryogenesis and the hemodynamics. To our knowledge, our case represents the first successful surgical repair of this combination of defects in Japan.

Brachiocephalic Veins↗
PubMed1989

Stimulation of connective tissue-type mast cell proliferation by crosslinking of cell-bound IgE.

Crosslinking of cell-bound IgE on mouse connective tissue-type mast cells (CTMC) by multivalent antigen or anti-IgE antibody induced clonal growth of CTMC in methylcellulose culture containing IL-3. Continuous presence of antigen, IgE antibody, and IL-3 in culture was required for extensive proliferation of CTMC. Optimal concentrations of antigen and anti-IgE antibody for proliferation of sensitized CTMC approximately corresponded to those for maximal histamine release from the cells, and it was observed that most dividing cells stimulated by antigen had pericellular degranulation halos in culture. Experiments of both single cell culture and serum free culture provided evidence for a direct effect of antigen stimulation on proliferation of CTMC. Neither accessory cells nor some factors in FCS were required for the clonal growth of CTMC in our culture condition. Compound 48/80, a direct stimulator of CTMC, also triggered histamine release from CTMC but failed to support their proliferation. These results suggest that stimulation of CTMC via IgE receptors not only triggers the release of chemical mediators from the cells but induces clonal growth of CTMC in the presence of IL-3. Our data indicate the possibility that antigen stimulation may play another role in the proliferation of CTMC.

Animals↗