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Biomedical subjects

K Noguchi

Publications and source records attributed to K Noguchi.

At least 451 records · Page 25Linked to original sources
PubMed1986

Testicular control of prostaglandin E2 production in rat vas deferens.

Orchidectomy decreased and testosterone (T) replacement restored prostaglandin E2 (PGE2) concentrations in adult rat vas deferens. To explain this finding, phospholipase A (PLase-A) and PG synthetic activity were studied in vas tissue from 9-week-old rats orchidectomized with or without T replacement as well as in rats in which the cauda epididymidis was ligated. PG synthetic activity fell to 3% of intact levels in 14-day castrate rats and was restored to normal by T replacement. Although vas PLase-A activity was also significantly (P less than 0.01) reduced to 38% of the control level in 14-day castrate rats, this change appears in part to reflect a castration-related increase in endogenous phospholipid concentrations. Further, T replacement only partially restored PLase-A activity to 59% of intact levels. Ligation of the cauda epididymidis in intact rats reduced vas PLase-A activity to castrate levels without altering vas T concentration. These results demonstrate both a direct effect of T on the biosynthesis of PGs in rat vas deferens as well as a paracrine effect, which appears to be mediated by a factor(s) other than T. These data suggest the existence of a new mechanism through which testicular products contribute to the function of the vas deferens.

Animals↗
PubMed1986

Comparison of acute hemodynamic effects of MC-838, a new angiotensin-converting enzyme inhibitor, with captopril in anesthetized dogs.

Effects of a new angiotensin-converting enzyme inhibitor, N-[3-(N-cyclohexanecarbonyl-D-alanylthio)-2-methylpropanoyl] -L-proline calcium (MC-838), on the systemic and coronary circulation were evaluated in anesthetized dogs, and the effects were compared with those of captopril. Administration of MC-838 (0.1, 0.3, 1.0 and 3.0 mg/kg, i.v.) produced a gradual and dose-dependent decline in aortic pressure associated with no marked changes in coronary blood flow, heart rate and LVdP/dt. Captopril (0.01, 0.03, 0.1 and 0.3 mg/kg, i.v.) also caused a dose-related decrease in aortic pressure, but the significant hypotension appeared more rapidly than that of MC-838. Both MC-838 and captopril inhibited selectively the pressor response to angiotensin I in a dose-related manner. The doses of MC-838 and captopril to lower mean aortic pressure by 10 mmHg from the pre-drug value were 2.8 mg/kg and 0.03 mg/kg, respectively; those of these drugs to cause 50% inhibition of angiotensin I-pressor response were 1.0 mg/kg and 0.04 mg/kg, respectively. When administration of MC-838 (3.0 mg/kg) was repeated three times at a 30 min-interval, the second and third injections caused no additional hypotension, while each of the repeated injections of captopril (0.3 mg/kg) produced significant hypotension. These results indicate that MC-838 inhibits angiotension I-conversion and decreases systemic blood pressure more slowly and persistently than captopril in anesthetized dogs.

Anesthesia↗
PubMed1986

Acute effects of bunazosin on aortic, vertebral, coronary and renal blood flows of anesthetized dogs.

Effects of 4-amino-2-(4-butyrylhexahydro-1H-1,4-diazepin-1-yl)-6,7-dime thoxy-quinazoline (bunazosin, E-643, Detantol) on aortic, vertebral, coronary and renal blood flows were investigated in anesthetized open-chest dogs. Bunazosin 1, 10 and 100 micrograms/kg i.v. dose-dependently decreased aortic blood pressure (AoP) and inhibited the increase in AoP by phenylephrine 5 micrograms/kg i.v. However, the increase in AoP by norepinephrine 0.5 microgram/kg i.v. remained even after bunazosin 100 micrograms/kg i.v. and was almost undetectable after additional administration of yohimbine 1000 micrograms/kg i.v. A hypotension by bunazosin persisted more than 15 min, but dose-dependent increases in heart rate (HR) induced by bunazosin 1, 10 and 100 micrograms/kg i.v. restored within 2 min. Bunazosin 100 micrograms/kg i.v. significantly but transiently increased aortic blood flow and decreased renal blood flow. Vertebral and coronary blood flows were not significantly changed. Left ventricular dP/dt was transiently increased. Calculated total peripheral vascular resistance and coronary vascular resistance were transiently but significantly decreased. No significant changes were observed in both vertebral vascular resistance and renal vascular resistance. The results indicate that bunazosin maintains the blood flows to brain, heart and kidney, and is continuously lowering AoP without significant changes in HR.

Adrenergic alpha-Antagonists↗
PubMed1986

Regulatory role of human bone marrow fibroblasts in proliferation by granulocyte and macrophage colony-forming cells.

Human bone marrow fibroblasts (BMF) regulate the proliferation of granulocyte and macrophage colony-forming cells (GM-CFC). The mechanism used by BMF to regulate the proliferation of GM-CFC was investigated. When target marrows contained few spontaneous colonies, BMF enhanced granulopoiesis, while BMF-conditioned medium (BMF-CM) failed to do so. When target marrows contained large numbers of spontaneous colonies and when colony-stimulating factor (CSF) was present in the cultures, BMF and BMF-CM inhibited granulopoiesis. Adherent cells were necessary for the stimulation of granulopoiesis by BMF, but not for the inhibition of granulopoiesis by BMF and BMF-CM. Interaction of BMF with GM-CFC in dishes for a short time inhibited colony formation by GM-CFC. From these data, it has been concluded that the BMF regulate granulopoiesis and maintain the homeostasis of granulopoiesis through cell-cell interaction and factors produced by the BMF.

Adult↗
PubMed1986

Comparison of vasodilating effects of nisoldipine and nifedipine in anesthetized open-chest dogs.

Hemodynamic effects of nisoldipine (Bay k 5552) were compared with those of nifedipine in anesthetized open-chest dogs. Both nisoldipine and nifedipine produced a fall in aortic pressure and increases in aortic, vertebral and coronary blood flows. After administration of nisoldipine, renal blood flow, heart rate and left ventricular enddiastolic pressure were not changed, but left ventricular dP/dt was increased. After administration of nifedipine, renal blood flow and left ventricular dP/dt were decreased, and left ventricular enddiastolic pressure was elevated. Heart rate was hardly changed. Durations of increases in aortic, vertebral and coronary blood flows were about 3 times longer after nisoldipine than after nifedipine. Percent decrease in coronary vascular resistance was greater and percent decrease in renal vascular resistance was smaller than that in total peripheral vascular resistance with both nisoldipine and nifedipine. Results indicate that nisoldipine and nifedipine produce marked coronary vasoldilation and the vasodilating effect of nisoldipine lasts longer than that of nifedipine.

Anesthesia↗
PubMed1986

Small-dose cytosine arabinoside in the treatment of elderly patients with acute leukemia and refractory anemia with excess of blast.

Five elderly patients with acute nonlymphocytic leukemia (ANLL) and four patients with refractory anemia with excess of blast (RAEB) were treated with small doses of Ara-C (5-30 mg/day, subcutaneous injection) for 10-28 days. Three patients achieved complete remission and four patients partial remission. Side effects were severe bone marrow suppression in eight patients and gastrointestinal symptoms in three patients. From these results it was indicated that a small-dose Ara-C regimen provides alternative therapy in selected elderly patients with ANLL and RAEB.

Acute Disease↗
PubMed1986

Effects of the water extract of Chrysanthemum indicum Linn. on coronary and systemic hemodynamics in the dog.

To clarify the pharmacological profile and the mechanism of action of the water extract of flower of Chrysanthemum indicum Linn. (CIL), a crude drug, the effects of CIL on coronary and systemic hemodynamics were examined in anesthetized open-chest dogs, and the coronary relaxing action of CIL was tested on isolated dog coronary arterial strips. Intravenous administration of CIL 5-20 mg/kg produced a decrease in aortic blood pressure and increases in coronary blood flow, left ventricular dP/dt and heart rate in a dose-dependent manner. Renal blood flow initially decreased and then increased to the values above the preinjection level. These changes by every dose of CIL returned to the preadministration level until 5 min. Dipyridamole (0.1 mg/kg i.v.) potentiated an increase in coronary blood flow of CIL and aminophylline (1.0 mg/kg i.v.) attenuated this response. Intravenous administration of adenosine 5-50 micrograms/kg produced effects similar to those of CIL. The doses of CIL and adenosine which produced a two-fold increase in coronary blood flow were 13.8 mg/kg and 29.5 micrograms/kg, respectively. In 30 mM potassium-induced contracture of dog coronary arterial strips, there was no difference in the relaxant response to CIL between large coronary arteries and medium-size coronary arteries. Adenosine tended to produce a larger relaxation in medium-size coronary arteries than in large coronary arteries. The results indicate that CIL has a coronary vasodilating action and a renal vasoconstricting action in the open-chest dog and that the pharmacological profile of CIL is in part similar to that of adenosine.

Adenosine↗
PubMed1986

[Infantile optic glioma involving the whole optic pathway--a case report].

A case of infantile optic glioma involving the whole optic pathway is reported. The patient was a 4-month-old female. The mother noticed that the baby could not follow the object, although her physical development had been apparently normal only until three months after birth. On admission, she was lethargic, although no definite motor weakness was identified. The ophthalmological check revealed delayed bilateral pupillary light reaction and choked disks. Skull X-ray film showed the J-shaped sella and the enlarged bilateral optic canals. CT scan also revealed an isodensity mass in the suprasellar cistern and enlarged bilateral optic nerves. The lesions were enhanced homogeneously with contrast medium and extended toward both optic radiations. Lateral ventricles were mildly dilated. Cerebral angiography showed the upward shift of A1-portion of the bilateral anterior cerebral arteries and the backward shift of the basilar artery. No abnormal vessels were visible. A bifrontal craniotomy was performed to partially remove the suprasellar tumor. The histological diagnosis was optic glioma. The postoperative course was uneventful. The patient was discharged without any neurological deficits except poor visual acuity. Four months later, she suddenly fell into generalized convulsion. CT scan revealed the significant enlargement of residual tumor and ventricular dilatation. Surgical treatment of VP shunt was immediately performed on, and then irradiation of 4,000 rad of total dose to the tumor followed. The tumor size became definitively small. On a follow-up term of 15 months, the patient has been doing well.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral Angiography↗
PubMed1986

Relations between collateral flow and tissue salvage in the risk area after acute coronary occlusion in dogs: a topographical analysis.

Localization of salvaged tissue after occlusion of the left anterior descending coronary artery due to collateral blood flow within the risk area was examined in a canine model using differential autoradiography. 125I tracer microspheres were injected into the left anterior descending artery preocclusively to define the perfusion territory as a risk area. 99mTc labelled human serum albumin microspheres were injected into both the left main and right coronary arteries 48 h after ligation to determine the collateral flow area. Using a cryotome, 50 micron transverse sections of the whole heart were taken, and 125I and 99mTc autoradiograms were obtained independently. The same specimens were stained by the nitroblue-tetrazolium method to demarcate the intact and infarcted myocardium. The tracings of the infarct, risk and collateral areas were compared and measured by a plainmeter. The collateral blood flow was distributed to 86, 55 and 42% of the epi, mid- and endo-cardial portions of the risk area respectively (P less than 0.001 between the epi- and mid- or endo-cardium). Within the collateral area 88, 58 and 63% of the epi-, mid- and endo-cardial portions were free of myocardial necrosis (P less than 0.001 between the epi- and mid- or endo-cardium). There was a close linear relationship between the size of salvaged and collateral areas (r = 0.96, P less than 0.001). Thus, a topographical analysis of the tissue salvage inside the risk area demonstrated the indispensable role of collateral blood flow for maintaining tissue viability.

Animals↗
PubMed1985

Separation of human Glu-plasminogen, Lys-plasminogen and plasmin by high-performance affinity chromatography on Asahipak GS gel coupled with p-aminobenzamidine.

Human Glu-plasminogen, Lys-plasminogen and plasmin were effectively separated by high-performance affinity chromatography. The affinity adsorbent was prepared by using a micro-particulate polyvinyl alcohol gel (Asahipak GS-gel) as the supporting material and p-aminobenzamidine as the specific ligand. All of the active enzyme and proenzymes were adsorbed. Glu-plasminogen was eluted by changing the pH of the eluent and Lys-plasminogen by using an eluent containing 6-amino-hexanoic acid. This affinity adsorbent recognized the difference between these proenzyme species. For the elution of plasmin, addition of urea was necessary. Plasmin may have been adsorbed through a two-site interaction with the adsorbent. All proteins were eluted as sharp peaks and the time required for one cycle was about 1 h. Fluorimetric detection of eluted protein and on-line assay of enzyme activity using a fluorigenic substrate made it possible to analyse microgram amounts of proteins specifically.

Animals↗
PubMed1985

High-performance affinity chromatography of trypsins on Asahipak GS-gel coupled with p-aminobenzamidine.

An adsorbent for high-performance affinity chromatography of trypsins was prepared, based on a micro-particulate polyvinyl alcohol gel for high-performance liquid chromatography, Asahipak GS-gel. After the hydroxyl groups had been activated with 1,1'-carbonyldiimidazole, 6-aminohexanoic acid was coupled as a spacer, then p-aminobenzamidine, a specific ligand for trypsin-family enzymes, was immobilized on the spacer. Fluorometric detection of eluted protein and on-line assay of enzyme activity using a fluorogenic substrate, peptidylmethylcoumarylamide, made it possible to attain very high sensitivity. Microgram amounts of bovine trypsin and Streptomyces griseus trypsin could easily be analyzed in a short time (less than 1 h).

Adsorption↗
PubMed1985

Estimation of catecholamines by ion-exchange chromatography on Asahipak ES-502C, using glycylglycine as the post-derivatizing agent.

The estimation of catecholamines in human urine was carried out by ion-exchange chromatography on a column of a weakly acidic ion exchanger with an hydrophilic matrix. The catecholamines were first adsorbed onto Amberlite CG-50 (buffered at pH 6.5 with 0.4 M phosphate buffer) and selectively eluted by 0.66 M boric acid solution. They were then separated from impurities that responded to fluorometric detection by isocratic elution from a column of Asahipak ES-502C, a cross-linked vinyl alcohol copolymer with carboxymethyl groups, at 60 degrees C. The mobile phase was 0.05 M sodium succinate buffer pH 5.25 containing 0.015 M borate and 0.5 mM ethylenediaminetetraacetate. Isoproterenol was used as the internal standard; epinephrine, norepinephrine, isoproterenol and dopamine were eluted in this order. One sample could be analyzed every 35 min. The detection limits were 0.2 ng for epinephrine and norepinephrine, 0.6 ng for dopamine. The elution pattern was quite reproducible; the elution volumes of the catecholamines had not changed after 500 determinations.

Catecholamines↗