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Biomedical subjects

S Uchida

Publications and source records attributed to S Uchida.

At least 541 records · Page 30Linked to original sources
PubMed1982

Studies on the sex-specific lethals of Drosophila melanogaster. IV. Gynandromorph analysis of three male-specific lethals, mle, msl-2(27) and mle(3)132.

Mutants at three male-specific lethal loci of Drosophila melanogaster (mle, msl-2(27) and mle(3)132) were examined by gynandromorph analysis. In all cases only a very few gynandromorphs with small X/O patches appeared. Most of these small X/O patches were in the abdomen, and the structures in these X/O regions were reduced in size. These results indicate that the primary effects of these mutants are not on any particular organs or tissues, but rather on individual cells, mle and msl-2 have been shown by BELOTE and LUCCHESI (1980a) to be defective in dosage compensation in X/Y males. We suggest that this dosage-compensation defect results in the expression of Minute-like phenotypes in X/O cells, and hence results in the death of X/O males and flies with large X/O tissue areas.

Animals↗
PubMed1982

Developmental changes in alpha-adrenergic and muscarinic receptor-mediated contractions of rat vas deferens.

Studies were made on developmental changes in phasic contractions of isolated rat vas deferens in response to norepinephrine (NE) and acetylcholine (ACh), which are mediated by alpha-adrenergic and muscarinic cholinergic receptors (alpha-R and m-R). The ED50 values of both contractions were almost constant during development, but the maximum responses to NE and ACh per wet weight and the relative contractions by NE and ACh to that by 100 mM K+ decreased greatly between 3 and 8 weeks after birth. However, the alpha- and m-receptors, assayed by measuring binding of [3H]-WB4101 and [3H]-quinuclidinyl benzylate (QNB), increased quantitatively per g wet weight and per mg protein between 2 and 8 weeks after birth, but did not change qualitatively. Thus, a discrepancy between the increases of alpha- and m-receptors and decreases of the maximum responses to NE and ACh was found, and possible mechanisms for this are discussed.

Acetylcholine↗
PubMed1982

Regulation of the alpha-adrenergic system in rat vas deferens.

Regulation of the supersensitivity and subsensitivity of the alpha adrenergic (alpha-Ad) system of rat vas deferens cultured under various experimental conditions was investigated. Muscles cultured for 3 days in normal medium (Eagle's MEM) exhibited marked increase in maximal contraction to noradrenaline (NA) and high K+ (154 mM), while muscles cultured with NA (100 microM) were subsensitive to the stimulants. Studies on the binding of 3H-WB4101, an alpha-Ad antagonist, to the homogenates of normal, supersensitive and subsensitive muscles revealed that the changes in NA-sensitivity were not accompanied by changes in the number or affinity of alpha-Ad receptors in the muscles. The effect of NA in decreasing NA-sensitivity was depressed by an inhibitor of protein synthesis, puromycin or cycloheximide. These results suggest that NA may be important in regulation of the contraction, at least in part through protein synthesis, without affecting the number or affinity of alpha-Ad receptors.

Adrenergic alpha-Antagonists↗
PubMed1981

Receptor-activated and energy-dependent decrease of muscarinic cholinergic receptors in guinea-pig vas deferens.

Organ cultures of guinea-pig vasa deferentia were used for studying both the decrease in muscarinic cholinergic receptor (mAChR) concentration induced by muscarinic agonists and the simultaneous decrease in contraction to ACh. After a lag period the decrease followed first-order kinetics and was completely blocked by atropine. The decrease was dependent not only on the extent of occupation of mAChR by ACh, but was also related to the efficacy of agonists as deduced from the contractions. Moreover the amount of mAChR was not affected by other contractile agents, norepinephrine and high K+ even under conditions in which mAChR was occupied by atropine or pilocarpine. These findings indicate that the decrease in the amount of mAChR mediated by muscarinic receptors in vas deferens was due to the extent of both receptor occupation and receptor activation by agonists. Furthermore it was shown that the decrease involved energy- and temperature-dependent processes and that cyclic nucleotides did not regulate the quantitative level of mAChR.

Animals↗
PubMed1981

Organization of viral genome in a T antigen-negative hamster tumor induced by human papovavirus BK.

We analyzed by blot hybridization the state and structure of the viral DNA in an exceptional BK virus-induced hamster tumor (choroid plexus papilloma Vn-324) that contains about one copy of the BK virus genome per cell, but no intranuclear T antigen as assayed by indirect immunofluorescence. The BK viral DNA was found to be integrated into cellular DNA at a site in the middle of the early region of the viral genome (between 0.32 and 0.41 map units). The structure of the inserted viral DNA shows that it cannot encode a full-size large T antigen, but may encode small T antigen and an N-terminal portion of large T antigen.

Animals↗
PubMed1981

A GTP-protein activator of phosphodiesterase which forms in response to bleached rhodopsin.

A specific protein associated with rod-outer-segment disc membranes binds GTP only in the presence of bleached rhodopsin. Once formed the protein-GTP complex becomes a soluble activator of cGMP phosphodiesterase. It is shown that this activator complex can be completely separated from rhodopsin and retain its ability to activate phosphodiesterase when added to a pool of totally dark (unilluminated) disc membranes. The photoreactive GTP analogue p3-(4-azidoanilido)-5' GTP (AAGTP) is shown to be a more effective substrate than GTP, Gpp(NH)p or 8-azido GTP. [8, 5' 3H] AAGTP was used to specifically covalently label the GTP-binding protein. The protein labeled exhibits a mass of 40,000 daltons when analyzed by SDS-PAGE.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1981

Sexual problems of women with rheumatoid arthritis.

A questionnaire concerning sexual problems was given to 112 female rheumatoid arthritic (RA) patients. Replies were collected from 91 (81%). The results indicated that 1) recently married patients were concerned about pregnancy; 2) the sexual desire of most patients diminished, and intercourse became less frequent and less satisfying; 3) affected hip and knee joints made it difficult to assume sexual intercourse positions; and 4) patients who had unsatisfying sexual relationship reported a decreased demand for intercourse by their spouses and diminished frequency of their own orgasms. To lead a fulfilling married life, patients with RA should be counselled to adopt a positive attitude toward sexual relationship with their husbands.

Arthritis, Rheumatoid↗
PubMed1980

Increase in response and number of alpha-adrenoceptors of rat vas deferens on brief pretreatment with an alpha-agonist.

The contractile response of rat vas deferens to epinephrine (E) was enhanced by preincubation with E. After pretreatment with E, there was no significant change in the ED50 of E but there was a significant increase in the maximum response (39%). There was no change in the cholinergic response after the pretreatment. alpha-Adrenoceptors in control and E-treated tissues were assessed by measuring [3H]WB-4101 binding. Treatment with E resulted in a 27% increase in the number of alpha-adrenoceptors, but no change in muscarinic acetylcholine receptors measured with [3H]quinuclidinyl benzilate. These results are discussed in relation to the response of alpha-adrenoceptors to the agonist.

Adrenergic alpha-Agonists↗