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Biomedical subjects

K Uchida

Publications and source records attributed to K Uchida.

At least 1,441 records · Page 80Linked to original sources
PubMed1982

[Total blood volume in essential and secondary hypertension].

To study the role of volume factors in the pathogenesis of hypertension, total blood volume (TBV) was determined in 43 patients with essential hypertension, 10 with primary aldosteronism, 5 with Cushing's syndrome, 5 with renovascular hypertension and 23 age-matched normotensives. The radioisotope (131I) labeled plasma tracer technique was employed under conditions of constant sodium intake (200mEq/day). The TBV values obtained were expressed as % normal against the predicted values according to the formulae of Fujita and his co-workers. The results were as follows: (1) TBV was increased in patients with primary aldosteronism. (2) In essential hypertensive patients, with either normal or low plasma renin activity, TBV was normal. (3) There was no increment of TBV in patients with Cushing's syndrome. These results suggest that expanded intravascular volume plays a major role in the mechanism of hypertension with suppressed plasma renin activity in primary aldosteronism, whereas other unknown factors may be related to the causes of hypertension in patients with essential hypertension and Cushing's syndrome.

Adult↗
PubMed1982

Distribution of cerebellar fiber terminals in the midbrain visuomotor areas: an autoradiographic study in the cat.

Cerebellar fibers to the midbrain visuomotor areas were traced in the cat auto-radiographically after injections of tritiated amino acids into individual cerebellar nuclei. Fibers from the dentate (DN), anterior interpositus (AIN) and posterior interpositus (PIN) nuclei were distributed contralaterally, while those from the fastigial nucleus (FN) bilaterally. The FN fibers appeared to arise mainly from the caudal half of the FN. In the superior colliculus (SC), the FN or DN fibers were more numerous than the PIN fibers, and the areas of termination of the FN fibers were located more medially than those of the DN and PIN fibers. These cerebellotectal fiber terminals were in the intermediate and deep SC layers; clustering of terminal silver grains was noted in the FN and DN fibers-recipient areas in the intermediate gray layer. In the pretectum, the DN fibers terminated ventrally in the reticular part of the anterior pretectal nucleus and the posterior pretectal nucleus. THe AIN fibers terminated ventrally in the compact part of the anterior pretectal nucleus and the posterior pretectal nucleus. The nucleus of the posterior commissure received cerebellar fibers chiefly from the DN, and additionally from the FN. The nucleus of Darkschewitsch and the interstitial nucleus of Cajal received fibers from all cerebellar nuclei. No cerebellar fibers terminated in the extraocular motor nuclei and the Edinger-Westphal and anteromedian nuclei.

Animals↗
PubMed1982

Cytochemical demonstration of amine-storing vacuoles and lysosomes in the chicken thrombocytes.

A combined electron microscopic and cytochemical study of the thrombocytes of the chicken has clearly identified the amine-storing organelles and lysosomes. A chromaffin positive-reaction product was observed on the inner surface and the granules of the large electron-lucent vacuoles. No acid phosphatase activity was localized in these amine-storing vacuoles. However, the acid phosphatase activity was observed in the small vesicles, the primary lysosomes, and in the large electron dense inclusions with myelin which may be secondary lysosomes. The results of this study suggest that the large empty vacuoles, with one or two very dense osmiophilic peripherally-situated granules, in the chicken thrombocytes are comparable to the vesicles with electron dense materials called "dense bodies" in mammalian thrombocytes.

Acid Phosphatase↗
PubMed1982

Phenotypic variations in re-lysogenization of Bacillus licheniformis with temperate phage.

A bacitracin-producing strain Bacillus licheniformis ATCC 10716 harbors two types of inducible phages (LP52 and DLP 10716). 156 strains re-lysogenized with phage LP52 were independently isolated from a cured strain UM12 of B. licheniformis. Those strains were divided into 12 groups based on colony morphology and pigment production. Some of the re-lysogenized strains grew faster than UM12 and others produced more bacitracin than the cured strain. For example, the production of bacitracin by one of the re-lysogenized strains, L89, was enhanced by about 70% in comparison with UM12. The phenotypic variations observed with re-lysogenized strains might be due to the re-insertion of the phage genome at different sites of the chromosome in addition to the pleiotropic effect assumed.

Bacillus↗
PubMed1982

The course of Angiostrongylus cantonensis infection in athymic nude and neonatally thymectomized mice.

BALB/c athymic nude and thymus-reconstituted nude mice and neonatally thymectomized BALB/c mice were infected with stage 3 larvae of Angiostrongylus cantonensis and the worm burdens of the mice were determined at various times after infection. When the nude and thymectomized mice were exposed to the parasite, some worms were found to migrate from the brain to lungs but died there without reaching maturity. This pulmonary arterial migration of the worms in the nude did not occur following thymic reconstitution. These data suggest that the inability of murine intracranial worms to migrate to the lungs is at least in part due to thymus-dependent mechanisms, and also that the failure of worm maturation in mouse lungs might be due to thymus-independent immune mechanisms and/or nonimmunological mechanisms.

Angiostrongylus↗
PubMed1982

Hepatic bile acid elution by albumin and bile acid content in isolated rat hepatocytes.

Bile acid contents were determined for isolated rat hepatocytes. During the course of isolating the hepatocytes, perfusion of rat liver with buffer containing 2% albumin eluted a significant amount of bile acids. The elution was proportional to the volume of the buffer and attributable to albumin in the buffer. The isolated hepatocytes prepared by perfusion with 0.1% albumin buffer, which eluted a negligible amount of bile acids, contained 95 +/- 12 micrograms/10(8) cells of bile acids. The major bile acids were cholic acid (22%), beta-muricholic acid (34%) and hyodeoxycholic acid (10%). Levels of the other bile acids were less than 3%. Peak 8, unidentified but presumed to be a trihydroxycholanoic acid, accounted for 19%.

Animals↗
PubMed1982

Age-related changes in cholesterol and bile-acid metabolism in spontaneously hypertensive rats.

Age-related changes in serum and liver cholesterol, phospholipid and triglyceride levels, serum lipoproteins, biliary secretion of cholesterol, phospholipids and bile acids, fecal excretion of sterols and bile acids, and the pool size of bile acids were examined in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKR). SHR showed distinct age- and sex-related changes when young and marked aged-rat hypercholesterolemia after 1 yr of age. (1) Cholesterol shifted from blood to the liver between 10 and 20 wk only in male SHR and not at all in WKR. (2) Serum lipoprotein percentages changes; alpha-lipoprotein decreased, pre-beta-lipoprotein increased, but beta-lipoprotein did not change. These changes appeared only in male SHR and after 13 to 15 wk of age. (3) Liver enlargement in SHR, although not detected at 5 to 6 wk, progressed more rapidly than in WKR, giving values almost double those in WKR after 13 to 15 wk. Liver enlargement in female SHR was much less than in the male. (4) Bile flow, biliary secretion, and the pool size of bile acids increased. However, when expressed on the basis of liver weight, these values were similar to those in WKR, suggesting that the increases were caused by the hepatomegaly. (5) Differences appeared in the bile acid composition. A large amount of beta-muricholic acid was present in SHR of both sexes and the cholic acid percentage was low in male SHR. (6) Changes were observed in fecal bile acid excretion. Since the daily amounts in male SHR were similar to those in WKR, the hepatic synthesis activity (mg per day per 10 g liver) in male SHR was almost half that in WKR at all ages.

Aging↗
PubMed1982

Inhibitory actions of catecholamines on electrically induced contractions of the submucous plexus-longitudinal muscularis mucosae preparation of the guinea-pig oesophagus.

1 The submucous plexus-longitudinal muscularis mucosae preparation of the guinea-pig oesophagus was used to study the actions of catecholamines on the twitch responses to electrical stimulation.2 When the preparation was stimulated coaxially (0.1 Hz, 0.5 ms, supramaximal voltage), stable twitch-like contractions were obtained. These were abolished by tetrodotoxin (0.1 muM) and atropine (0.1 muM), potentiated by physostigmine (0.1 muM), and were mediated presumably by stimulation of intramural cholinergic nerves.3 The twitch contractions of the muscularis mucosae were inhibited by catecholamines, in a concentration-dependent manner. The order of potency was isoprenaline > adrenaline > noradrenaline > dopamine.4 The inhibitory actions of noradrenaline (1 muM) and adrenaline (1 muM) were partly reversed by phentolamine (1 muM) or by propranolol (1 muM), and completely abolished by both antagonists together. The inhibitory effect of dopamine (300 muM) was largely reversed by phentolamine (1 muM), but not by propranolol (1 muM), while the inhibitory action of isoprenaline was competitively antagonized only by propranolol (pA(2) of 7.6).5 The contraction of the muscularis mucosae to exogenously applied acetylcholine (ACh, 20 nM) which was comparable in magnitude with that to electrical stimulation was also inhibited by isoprenaline (0.1 muM), adrenaline (1 muM) and noradrenaline (1 muM), but not by dopamine (300 muM). In the presence of propranolol (1 muM), noradrenaline, adrenaline and dopamine potentiated the ACh-induced contraction, while the effect of isoprenaline was mainly antagonized. The potentiating effects were antagonized by further treatment with phentolamine (1 muM).6 Adrenaline, noradrenaline and dopamine but not isoprenaline, produced a weak contraction of the longitudinal muscularis mucosae in the presence of propranolol (3 muM). The contractile responses were completely inhibited by phentolamine (3 muM). Tone in the muscularis mucosae induced by carbachol (3 muM) in the presence of phentolamine (10 muM) was inhibited by catecholamines, in a concentration-dependent manner, an effect that was competitively antagonized by propranolol.7 In the submucous plexus-longitudinal muscularis mucosae preparation of the guinea-pig oesophagus there are three types of adrenoceptor, inhibitory prejunctional alpha-adrenoceptors, excitatory postjunctional alpha-adrenoceptors and inhibitory postjunctional beta-adrenoceptors, and cholinergic neurotransmission is inhibited by catecholamines acting at both prejunctional alpha- and postjunctional beta-adrenoceptors.

Animals↗
PubMed1982

Clinical experience of postoperative hepatic failure treatment with pig or baboon liver cross-hemodialysis with an interposed membrane.

The present study emphasizes the principle of using liver support to restore the blood ketone body ratio (acetoacetate/beta-hydroxybutyrate), which reflects the redox potential of liver mitochondria and correlates with hepatic energy charge (ATP + 0.5ADP/ATP + ADP + AMP). Eleven surgical patients with grade IV hepatic coma were treated by an ex vivo pig or baboon liver cross-hemodialysis with an interposed Cuprophan membrane when their blood ketone body ratios had decreased to below 0.4 compared with the normal of above 0.7. Three patients were treated by cross-hemodialysis using a standard Cuprophan membrane dialyzer without increase of blood ketone body ratio and without marked beneficial effect. However, five of eight patients who had blood ketone body ratios of above 0.25 became fully alert after treatment by cross-hemodialysis using the larger pore size and greater surface area Cuprophan membrane, concurrent with a rise in the decreased blood ketone body ratio, and three of them were later discharged. By contrast, in the three patients with blood ketone body ratios below 0.25, there was no restoration of consciousness and no improvement in their blood ketone body ratios by this liver support. It is suggested that, as long as the blood ketone body ratio remained over 0.25, this metabolic liver support is effective in restoring grade IV hepatic coma.

Aged↗
PubMed1982

The effects of heterologous liver cross-hemodialysis on adenylate energy charge of the remnant liver after major hepatic resection.

The effect of liver support on the adenylate energy charge (ATP + 0.5ADP)/(ATP + ADP + AMP) of the remnant liver after major hepatic resection was studied in rabbits. The present study emphasized the principle of restoring the decreased energy charge level of the remnant liver after major hepatic resection by use of an ex vivo heterologous liver cross-hemodialysis with an interposed Cuprophan membrane. The energy charge level provides the cell with a very sensitive intracellular control mechanism. Regulatory enzymes from biosynthetic sequences exhibit very little activity at low levels of energy charge, and their activities increase sharply at high-energy charge levels. The energy charge level of the remnant liver maximally decreased from the control level of 0.860 to 0.767 at 24 hours after 70% hepatectomy. The energy charge level increased from 0.767 to 0.857 after two hours of cross-hemodialysis with an interposed Cuprophan membrane between the 24-hour, 70% hepatectomized rabbit and an ex vivo pig liver with high energy charge. The above results suggest that this ex vivo pig cross-hemodialysis may be effective for biosynthesis in the regenerative processes of the remnant liver.

Adenosine Monophosphate↗
PubMed1982

Cytoplasmic transfer of oligomycin resistance during protoplast fusion of Saccharomycopsis lipolytica.

Mitotic segregation of oligomycin resistance and oligomycin sensitivity was observed among the prototrophic progeny of protoplast fusion between drug-resistant and drug-sensitive complementary auxotrophs of Saccharomycopsis lipolytica. The transfer of oligomycin resistance by protoplast fusion without karyogamy suggests a cytoplasmic inheritance of this drug resistance determinant.

Ascomycota↗
PubMed1982

Effect of the catecholestrogen 2-hydroxyestradiol on the renin-angiotensin system in the rat.

The effects of the catecholestrogen 2-hydroxyestradiol (250 and 500 micrograms/day, each for 7 days) on plasma renin substrate (PRS), activity (PRA) and concentration (PRC) were studied in male rats as compared with those of estradiol (250 micrograms/day, for 7 days) and vehicle alone (for 7 days). Pre-treatment levels of PRS, PRA, PRC and the PRA/PRC ratio were similar in four groups. After vehicle treatment, PRS, PRA, PRC and the PRA/PRC ratio remained unchanged. Estradiol treatment, however, produced an increase in PRS, an increase in PRA but no change in PRC. The PRA/PRC ratio after estradiol treatment was high. On the other hand, 2-hydroxyestradiol treatment caused no increase in PRS at a daily dose of 250 micrograms and a slight but significant increase in PRS at a daily dose of 500 micrograms. This treatment also produced increases in PRA as well as PRC at the two daily doses. These increases in PRA and PRC tended to be higher at a daily dose of 500 micrograms than at a daily dose of 250 micrograms. The PRA/PRC ratios after 2-hydroxyestradiol treatment were unaltered at the two daily doses. It is concluded that, while 2-hydroxyestradiol is less active in increasing PRS than estradiol, the compound is capable of increasing PRC.

Angiotensinogen↗
PubMed1982

Reversible hypertension caused by calcium overloading in a patient with postoperative hypoparathyroidism.

A 37-year-old woman with postoperative hypoparathyroidism had hypertension, and elevated plasma renin activity (PRA) and subsequent hyperaldosteronism during a two-month hypercalcemic period caused by vitamin D and excessive calcium supplements. The hypertension with elevated PRA, however, was resistant to the angiotensin II (AII) analog [Sar1, Ile8] ALL. PRA further increased and plasma aldosterone decreased in response to the [Sar1, Ile8] ALL. When the patient became normocalcemic, normotensive and normoreninemic, calcium gluconate (5 mg calcium/kg/h) was infused for one hour. The calcium infusion reproduced hypercalcemic hypertension mediated by an increase in total peripheral resistance. These observations suggest that the hypertension observed while taking vitamin D and excessive calcium supplements may be caused by a direct effect of calcium on peripheral blood vessels and the renin-angiotensin system may play a negligible role.

Adult↗
PubMed1982

Electron microscopic observations on single cilia in the intrahepatic biliary ducts in some birds.

The intrahepatic biliary passage in five species of birds was investigated with the transmission electron microscope. The avian liver was characterized by a frequent occurrence of intralobular bile ductules and canaliculo-ductular junctions in the parenchyma. It was further characterized by solitary bile ductular epithelial cells intercalated among hepatocytes surrounding bile canaliculi. The present study first revealed that avian bile ductular epithelial cells possess a long single cilium. Its basal body (distal centriole) was connected to a basal foot and slender rootlet and accompanied by a proximal centriole. The hepatocytes facing the bile passage possessed no cilium, although they frequently had a diplosome in their apical cytoplasm. The single cilia of the bile ductular epithelium gradually tapered toward the tip. The original fiber pattern in the most proximal part was peripheral 9 doublets +0. In the ciliary shaft, the doublets altered into singlets which were diminished in number gradually toward the distal parts of the shaft, so that in the tip only one singlet remained. Since these fiber patterns in the single cilia markedly deviated from the 9 + 2 fiber pattern of the ordinary motile cilia, they may not be motile, but properly regarded as sensory or chemoreceptors.

Animals↗
PubMed1982

Treatment of relapsed acute myelocytic leukemia with a combination of aclarubicin and cytosine arabinoside.

Relapses in nine patients with acute myelocytic leukemia were treated with a combination of aclarubicin (ACR) and cytosine arabinoside (ara-C). ACR, 40 mg/m2/day, was administered daily by intravenous injection from day 1 to day 3 and ara-C, 60-80 mg/m2/day, divided into 2 doses, was given every 12 h by intravenous infusion from day 1 to day 7. Depending on the state of the bone marrow, ACR-ara-C regimen was modified in administration period and repeated after the resting periods of at least 7 days. Complete remission was obtained in 7 of 9 patients (77.8%). The time required for achieving the complete remission varied from 20 to 55 days with a median of 39 days. The duration of complete remission was from 8 to 52 weeks with a median of 22 weeks. Side effects on digestive system such as nausea, vomiting and anorexia, were seen in all patients, although they were managed by symptomatic treatment. The results indicate the effectiveness of this ACR-ara-C regimen in the clinical management of acute nonlymphocytic leukemia.

Aclarubicin↗