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S Uno

Publications and source records attributed to S Uno.

At least 91 records · Page 5Linked to original sources
PubMed1990

Evidence for receptor-mediated inhibition of intrinsic activity of GTP-binding protein, Gi1 and Gi2, but not G0 in reconstitution experiments.

The receptor-mediated inhibition of intrinsic activities of GTP-binding proteins (G-proteins) was studied. Pertussis toxin (IAP)-substrate G-protein, Gi1, Gi2 or G0, was prelabeled with [alpha-32P]GDP and reconstituted with synaptic membranes of the guinea pig cerebellum in the presence of 0.02% of Chaps. Intrinsic activities of G-proteins were evaluated by the release of [alpha-32P]GDP in exchange for added GppNHp or GDP in reconstituted preparations. U-50,488H (1 nM-10 microM), a specific kappa-subtype of opioid receptor agonist, inhibited the [alpha-32P]GDP release in exchange for added 1 microM GppNHp in Gi1-reconstituted preparations in a concentration-dependent manner. On the other hand, the kappa-opioid agonist at 10 microM increases the Km values of GppNHp, but not GDP in exchange for [alpha-32P]GDP release in preparations reconstituted with Gi1 or Gi2, but not with G0. These findings indicate that kappa-opioid receptor is coupled to inhibition of intrinsic activities of Gi1 and Gi2, but not G0, in guinea pig cerebellar membranes. In addition, it was revealed that the mode of action is mediated by a decrease in affinity of GTP (or its analog) for G proteins, but not by a change in affinity of GDP.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1990

How is the flagellar length of mature sperm determined? II. Comparison of tubulin synthesis in spermatids between newt and Xenopus in vitro.

In order to elucidate mechanisms that control flagellar length of mature sperm, we studied in synchronous cell suspension cultures flagellar growth, tubulin pool, and tubulin synthesis in round spermatids of Xenopus laevis and the newt Cynops pyrrhogaster. The average final length of flagella in Xenopus round spermatids was 35 mum, almost the same length as that in mature sperm, whereas in the newt round spermatids, the length was 210 mum, almost half that of mature sperm. Kinetics of flagellar growth showed that the rate and period of flagellar growth in the newt spermatids were two to threefold those in Xenopus spermatids. The tubulin pool size in newt spermatids was estimated to be about 10-fold greater than that in Xenopus spermatids. But even if all of the pool was used for flagellar growth, it could support only about a seventh to a tenth of the flagellar length in mature sperm in either species. Thus, the possibility that the tubulin pool primarily determines flagellar length was excluded. Since the tubulin pool size did not change throughout the culture period, the possibility that the termination of flagellar growth is due to the exhaustion of the tubulin pool was also excluded. Tubulin synthesis declined over the culture period but continued in newt spermatids longer than in Xenopus spermatids. The period of flagellar elongation almost coincided with the period of tubulin synthesis. The amount of rRNA did not decrease, excluding the possibility that the decline of tubulin synthesis was due to cytoplasmic shedding which might result in the loss of ribosomes. Tubulin synthesis and the amount of rRNA in newt spermatids was more than threefold greater than that in Xenopus spermatids, which may explain the difference in growth rates of their flagella.

Acrosome↗
PubMed1990

Development of stable film test for rapid estimation of blood or plasma 3-hydroxybutyrate.

A film test for the rapid detection of plasma/serum 3-hydroxybutyrate (3-OHB) has been developed. The film contains NAD, nitro blue tetrazolium, 3-OHB dehydrogenase, and diaphorase, and the surface is coated with modified biomembrane and can detect 50-1500 microM 3-OHB within 2-3 min. One drop or 50 microliters of plasma/serum or blood is applied to the film, and the violet color is read via reflectance meter after 2 min. Plasma/serum samples greater than 1500 microM 3-OHB can be measured by dilution with saline. In blood with 40% hematocrit, the color developed is 50% less than with plasma/serum, and this was adjusted in the reflectance meter. A good correlation (r = 0.99) was observed between results with automated and film methods and between visual methods and reflectance meter. In insulin-dependent diabetes mellitus, all 3 subjects with positive ketonuria (+ +), 8 of 12 subjects with mild ketonuria (+), and 7 of 25 subjects without ketonuria exhibited elevation of 3-OHB in blood greater than 200 microM. The results indicate that 3-OHB film is valuable not only in the emergency room for the differential diagnosis between ketoacidotic and nonketotic hypersomolar coma but also as a marker for insulin dependency, energy dependency on fatty acid compared with glucose, and metabolic control of diabetes.

3-Hydroxybutyric Acid↗
PubMed1988

How is the flagellar length of mature sperm determined? I. Comparison of flagellar growth in spermatids between newt and Xenopus in vitro.

The kinetics of flagellar growth in round spermatids were compared between Xenopus laevis and Cynops pyrrhogaster in vitro, the latter of which has about 13 times longer flagella in mature sperm than the former. In both species, more than 90% of the spermatids derived from marked primary spermatocytes grew flagella. In Xenopus the average flagellar length increased to 28 microns by the 6th day and then stopped growth, while in the newt, flagellar growth did not stop until reaching 107 microns in average on the 10th day. Maximal length was 36-38 microns in Xenopus and 187 microns in the newt. Two major differences in kinetics of flagellar growth were found between the two species. First, the initial rate of growth in the newt was about double the rate in Xenopus. Second, the period of flagellar growth in the newt (10 days) was also about double the period in Xenopus (5-6 days). Actinomycin D (10 micrograms/ml) had no inhibitory effect on flagellar growth in either species, whereas cycloheximide (10 microM) inhibited flagellar growth by more than 80% in both species. These results indicate that translational control presumably of flagellar protein synthesis plays an important role in flagellar growth in both species and in the difference in flagellar length in spermatids between Xenopus and newt.

Animals↗
PubMed1988

Serological evaluation of ultrasound examination for chronic schistosomiasis japonica in a previously endemic area--the Chikugo River Basin, Japan.

Ultrasound diagnosis of chronic schistosomiasis japonica was assessed by comparison with the results of serological tests using enzyme-linked immunosorbent assay (ELISA) with egg and adult worm antigen, and the circumoval precipitation test. The subjects were persons resident in the Chikugo River Basin in Kyushu, southwest Japan, where schistosomiasis used to be highly prevalent. Of 93 individuals with a past history of infection, 37 (39.8%) presented the characteristic echo pattern of the disease (network, sieve, mottled or mixed pattern). In the serological tests, the ultrasound (US)-positive subjects showed a significantly higher IgG antibody-positive rate in ELISA (81.1% for egg-ELISA), than the US-negative subjects (37.5% for egg-ELISA). Individuals bearing dead Schistosoma japonicum eggs proven by tissue biopsy showed a similar antibody-positive rate (76.5% for egg-ELISA) to that of the US-positive subjects. Sera of a group which had no schistosomiasis characteristic echo pattern, but had liver fibrosis, hepatomegaly or liver cirrhosis as shown by US, were also highly positive (71.4% for egg-ELISA). The present serological studies thus confirmed the usefulness of ultrasound diagnosis for chronic schistosomiasis japonica. Furthermore, we were able to determine certain indications of liver abnormality currently undefined in the normally utilized US classifications.

Adult↗
PubMed1987

Heterotopic gastric mucosa accompanied by aberrant pancreas in the duodenum.

An operated case of a heterotopic gastric mucosa, accompanied by an aberrant pancreas tissue, in the bulb of the duodenum was reported. A 40-yr-old man complained of epigastralgia and was diagnosed to have a protruding lesion in the duodenum by roentgenological and endoscopic examinations. Partial excision of the duodenal wall including the mass was performed. Cut surface of the specimen showed a yellowish-whitish mass in the submucosal through the subserosal layers, which was covered by a papillary elevated mucous membrane. Histologically the mass was an aberrant pancreas of the Heinrich I-type and the mucous membrane covering the mass was a heterotopic gastric mucosa, consisting of completely developed fundic glands.

Adult↗
PubMed1984

Ketone bodies as markers for type 1 (insulin-dependent) diabetes and their value in the monitoring of diabetic control.

Serum levels of acetoacetate, 3-hydroxybutyrate and the 3-hydroxybutyrate/acetoacetate ratio were determined in Type 1 (insulin-dependent) and Type 2 (non-insulin-dependent) diabetic patients by a new sensitive method. Efforts were made to differentiate Type 1 and Type 2 diabetes by serum levels of ketone bodies and to determine whether their measurement is a useful way of monitoring diabetic control. In Type 2 diabetes, serum levels of total ketone bodies did not exceed 2.0 mmol/l even if the patients were untreated or poorly controlled. In Type 1 diabetic subjects, treated with once or twice daily injections of insulin, morning serum levels of acetoacetate, 3-hydroxybutyrate and total ketone bodies were significantly elevated by four-, ten- and sevenfold, respectively. In Type 2 diabetic subjects treated with diet or sulphonylureas, serum levels of 3-hydroxybutyrate were highest before breakfast, next highest before dinner and decreased after each meal. The changes were roughly inversely proportional to serum insulin levels. In addition, insulin treatment normalized fasting serum levels of ketone bodies better than diet or sulphonylurea treatment. Acetoacetate was also significantly increased in both types of diabetes to a lesser extent, but no apparent diurnal rhythm was observed. Determination of serum levels of ketone bodies is useful for the diagnosis of Type 1 diabetes (those with total ketone bodies greater than 2 mmol/l) and for detecting insufficient insulin therapy.

Acetoacetates↗
PubMed1984

Nuclear elongation of dissociated newt spermatids in vitro and their nuclear shortening by antimicrotubule agents.

Dissociated newt spermatids with an initial cell length of 20-35 microns increased in length at an average rate of 35-46 microns during 5 days of culture at 22 degrees C. 10(-5) M vinblastine sulfate shortened the length of nearly all the spermatids of various initial lengths to that of round spermatids within 24 h at 22 degrees C. Application of vinblastine to the spermatids immediately following initiation of nuclear elongation caused the nuclei to become completely round within 1 h. 3 X 10(-6) M colcemid, 10(-4) M colchicine, 2 X 10(-5) M nocodazole and 10(-4) M griseofulvin also shortened the spermatid length. The effects of these five antimicrotubule agents were irreversible. Neither 10(-4) M beta-, gamma-lumicolchicine nor 1.0 micrograms/ml cytochalasin B (CB) had any effect on spermatid elongation. Spermatids incubated at 4 degrees C for 6 days shortened by 20-50%, but after transfer to 22 degrees C they started to elongate. An ultrastructural study showed that during nuclear elongation the number of microtubules increased in proportion to the elongation, and that the microtubules surrounded the whole nucleus from its apical to caudal end. After addition of vinblastine many microtubular crystals appeared in the cytoplasm of the spermatids. It was concluded that microtubules are a prerequisite for nuclear elongation of newt spermatids, and it is speculated that microtubules act directly in the initiation and continuation of the nuclear elongation of newt spermatids.

Animals↗