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Biomedical subjects

K Sugimoto

Publications and source records attributed to K Sugimoto.

At least 577 records · Page 32Linked to original sources
PubMed1985

Primary structure of the beta-subunit of bovine transducin deduced from the cDNA sequence.

DNA complementary to the bovine retinal mRNA coding for the beta-subunit of transducin has been cloned by screening a cDNA library with oligodeoxyribonucleotide probes. Nucleotide sequence analysis of the cloned cDNA has revealed that this polypeptide consists of 340 amino acid residues (including the initiating methionine). Furthermore, cDNA hybridizable with a transducin beta-subunit cDNA probe has been cloned from a library derived from bovine brain poly(A)+ RNA. Comparison of the cloned cDNAs, in conjunction with blot hybridization analysis and S1 nuclease mapping of poly(A)+ RNA from bovine retina, brain and liver, suggests that the mRNAs coding for the beta-subunits of transducin and other guanine nucleotide binding proteins have the same protein-coding sequence but partly different 5'-noncoding sequences.

Amino Acid Sequence↗
PubMed1985

Peroxidase activity in the epithelium of the digestive tract of the bullfrog, Rana catesbeiana.

Peroxidase activity was examined cytochemically in the mucosal epithelium along the length of the digestive tract from the esophagus through the large intestine during the development of the bullfrog, Rana catesbeiana. In the tadpole of this species, cells with peroxidase activity were found abundantly in the esophagus, stomach, and large intestine; and the types of such cells differed according to the region: ciliated cells and mucous cells in the esophagus; ciliated cells in the stomach; and brush cells, absorptive cells, and goblet cells in the large intestine, respectively. After metamorphosis, however, peroxidase activity was observed exclusively in absorptive cells and goblet cells in the large intestine. Peroxidase activity was commonly demonstrated in apical vesicles or granules, to some degree in rough endoplasmic reticulum, and in some elements of the Golgi apparatus. Furthermore, reaction product was also found in mucus covering the luminal surface of such epithelial cells. These findings indicate that peroxidase-positive cells, which may have the ability to synthesize peroxidase as a secretory product, were distributed mainly in three regions of the digestive tract in tadpoles (esophagus, stomach, and large intestine), but were centered in one specific region, the large intestine, after metamorphosis. Concomitantly, the variety of types of peroxidase-positive cells decreased during metamorphosis. Our results indicate that some of the peroxidase in the digestive tract may have a secretory origin and may play a role in the defense against microorganisms.

Animals↗
PubMed1985

Provocation test for children with bronchial asthma monitored by 81mKr ventilation and perfusion lung scans.

A provocation test of bronchial asthma was performed on two children. The test involved the continuous inhalation of krypton-81m gas and intermittent intravenous injections of krypton-81m glucose solution. The patient's response was carefully monitored in order to clarify the relationship between the time of the appearance and the intensity of ventilation and perfusion defects. The bronchial sensitivity of each patient was determined according to the dose of allergen or bronchoconstrictor delivered before the first ventilation defects were observable. The test was sensitive enough for the children not to develop asthmatic symptoms during and after the test. The results showed that perfusion defects appeared after ventilation defects and were less intense. The perfusion defects disappeared rapidly and before the ventilation defects had become undetectable.

Adolescent↗
PubMed1985

[Effects of cyclosporine and blood transfusion on cardiac xenografts in combination of rat and mouse].

Transplant surgeons have been interested in the transplantation of vasculized organ xenografts. We studied the effects of Cyclosporine and blood transfusion on rat heart xenografts in mice and in reverse combination. B6AF1 mouse recipients were transfused with C3D2F1 mouse blood, presenting H-2k/d antigen and with B10.BR mouse blood transfusion, presenting H-2D and H-9 antigen to recipients. All rejected on day 5 in control group and C3D2F1 group. Prolongation of xenograft survival occurred with MST (Mean Survival Time) of 7.0 +/- 1.7 days (p less than 0.01), when primed by B10.BR blood transfusion. The survival time (MST = 14.4 +/- 3.2 days (p less than 0.001) of rat heart xenografts was prolonged in mice recipients treated with i.m. injection of 20 mg/kg/day of Cyclosporine for 14 days (short term). When B6AF1 mouse hearts were grafted into Lewis rats, however, no significant prolongation of graft survival occurred in any of Cyclosporine-treated rats. Cyclosporine did not prove to beneficial in this combination because of rat natural antibodies or species-specific barriers to mouse.

Animals↗
PubMed1984

Sequence organization of replication origin of the Escherichia coli K-12 chromosome.

A sequence of 245 base-pairs (oriC) in the replication origin of the Escherichia coli K-12 chromosome has been shown to provide all the information essential for initiation of bidirectional replication. In order to elucidate the sequence organization of oriC, numerous mutants carrying a single-to-multiple transitions from G X C to A X T base-pair were constructed by localized mutagenesis in vitro, which uses sodium bisulfite, and the correlation between the mutation sites and replicating ability (Ori function) was systematically analyzed. By isolating non-defective (Ori+) mutants with multiple base changes, transitions at 71 positions among 101 G X C pairs in oriC were found to have no effect on Ori function. Investigation of defective (Ori-) mutants, on the other hand, showed that individual replacements at 18 positions were detrimental to Ori function to some extent. These irreplaceable G X C pairs fell in the positions where no substitution was detected in the Ori+ mutants. The defect of the Ori- mutants with a single base substitution was generally weaker than that of the previously constructed Ori- mutants lacking a part of oriC. The addition of two or more base changes each giving a faint Ori- phenotype, however, resulted in a more intensive Ori- phenotype. We have previously demonstrated that oriC contains several regions where deletion or insertion of oligonucleotides leads to strong Ori- phenotypes. Transitions in those areas did not cause any defect of Ori function. Combining present results on base substitution mutants with the previous observations together, we assumed that the oriC sequence provides multiple interaction sites with replication initiation factors, and the precise arrangement of these sites are required for Ori function.

Base Composition↗
PubMed1984

An epidemiological study on carbon disulfide angiopathy in a Chinese viscose rayon factory.

To assess long-term vascular effects of occupational carbon disulfide (CS2) exposure, we examined 376 exposed and 325 unexposed Chinese workers with a medical and work-history questionnaire, a chest-pain questionnaire, blood pressure and blood cholesterol measurements, routine urinary tests, monochromatic fundus photography and other tests. Data from 354 exposed and 177 age- and sex-matched reference workers were evaluated. Personal exposure monitorings were performed simultaneously with a passive dosimeter using gas chromatography. Monochromatic fundus photography revealed no CS2-retinopathy characterized by microaneurysms and/or small dot hemorrhages, and no effects of CS2 on blood pressure and blood cholesterol were found. These negative results may have been due to the low daily exposure averages, which varied between 0.01 and 12.8, with a mean of 1.5 ppm. The present study suggested that the no-effect level of CS2 exposure on the development of retinopathy was around 2 ppm (8-h time weighted average), and the absence of adverse CS2 effects among the workers studied supported the current standard for occupational CS2 exposure of 10 mg m-3 in China.

Adult↗
PubMed1984

Ionic basis of resting membrane potential in frog taste cells.

Intracellular recording of the resting membrane potential was made from taste cells of the bullfrog by replacing the interstitial fluid surrounding the cells by various physiological saline solutions. The resting potential of the taste cell was -28 +/- 4 mV (mean +/- S.E.) after replacement of the interstitial fluid by normal Ringer solution. The resting potential was very much dependent on the interstitial K+ concentration ([K+]). Tenfold increase in [K+]o decreased the resting potential by 18 mV. Total removal of interstitial Na+ increased the resting potential by 40%. Ouabain in a concentration of 0.5 nM decreased the resting potential by 36% possibly due to inhibition of the Na+-K+ exchange pump. Neither total removal nor fourfold increase of interstitial Ca2+ changed the resting potential. Complete elimination of interstitial Cl- did not change the resting potential. The mean permeability ratio PNa/PK was calculated to be 0.41. It is concluded that the resting potential of a frog taste cell consists of ionic and metabolic components, and that the ionic component is due to the permeability of the cell membrane to K+ and Na+.

Animals↗