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Biomedical subjects

S Sugano

Publications and source records attributed to S Sugano.

At least 199 records · Page 11Linked to original sources
PubMed1989

Multiple molecular forms of cytochrome P-450SCC purified from bovine corpus luteum mitochondria.

Cytochrome P-450 related to side-chain cleavage of cholesterol (P-450SCC) was isolated from bovine corpus luteum mitochondria in the form of its stable cholesterol complex. The isolation procedure included ammonium sulfate fractionation and chromatography on omega-aminohexyl-Sepharose (AH-Sepharose). Corpus luteum P-450SCC was resolved into one minor (AH-I) and two major (AH-II and AH-III) fractions by the chromatography. Results of re-chromatography suggested the possibility that AH-III Fraction was originally complexed with lipidic material. The two major fractions purified by the re-chromatography (AH-IIR and AH-IIIR Fractions) showed essentially a single band on sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis and their absorption spectra were indistinguishable from each other. Both fractions were further resolved into two major and some minor bands of P-450SCC by isoelectric focusing on polyacrylamide gel in the presence of a non-ionic detergent, as detected by protein staining, heme staining and immunoblot analysis with anti-bovine P-450SCC monoclonal antibody. Both AH-IIR and AH-IIIR Fractions were further resolved by high-performance liquid chromatography (HPLC) on SP-TSK gel column into two fractions, SP-I and SP-II. These fractions had the same N-terminal amino acid sequence, showed similar catalytic activity and resolved into one major and a few minor bands on isoelectric focusing on polyacrylamide gel. Much more heterogeneity was observed in purified P-450SCC preparations from bovine adrenal cortex mitochondria. These results indicated the presence of multiple molecular forms of corpus luteum P-450SCC as well as adrenal cortex P-450SCC. Computer simulation studies were carried out in order to analyze the mechanism of formation of multiple bands on isoelectric focusing. The multiple bands of corpus luteum P-450SCC could be explained by postulating the presence of two isozymes (or molecular forms) having a pair of sites each with or without a charged group.

Adrenal Cortex↗
PubMed1989

Calf thymus histone H1 is a recombinase that catalyzes ATP-independent DNA strand transfer.

An activity that catalyzes the strand transfer from linear double-stranded tetracycline-resistance gene (tetr) DNA to circular M13mp8-tetr viral DNA was detected in a crude extract from calf thymus. This activity was purified to near, if not complete, homogeneity as judged by NaDodSO4/polyacrylamide gel electrophoresis. We have tentatively named this protein calf thymus strand-transfer protein 1 (CTST1). The apparent molecular mass of the protein was 35 kDa by gel electrophoresis. Its sedimentation coefficient was approximately 1.5 S in glycerol gradient centrifugation. These values led us to examine the possibility that CTST1 is histone H1. Western blot analysis of CTST1 with anti-rat liver histone H1 antiserum showed that CTST1 crossreacts with the serum, indicating that CTST1 is histone H1. The mobility of CTST1 was identical to one of the subtypes of calf thymus histone H1 by NaDodSO4/polyacrylamide gel and acetic acid/urea/polyacrylamide gel electrophoreses. We have also confirmed the above conclusion by showing that calf thymus histone H1 has a strand-transfer activity with a specific activity comparable to that of CTST1. The reaction required homologous substrates, but neither Mg2+ nor ATP. The reaction also required stoichiometric amounts of protein. The purified CTST1 fraction lacked detectable exo- and endonuclease activities and also lacked a DNA helicase activity.

Animals↗
PubMed1989

Relation of intrinsic heart rate and autonomic nervous tone to resting heart rate in the young and the adult of various domestic animals.

Intrinsic heart rate (IHR) and autonomic nervous tone (ANT) were measured using the young and the adult of horses, cows, pigs, goats and chickens in order to elucidate species differences in a decrease of resting heart rate (RHR) with growth or age. The IHR and ANT were estimated from the changes in heart rate after the administration of atropine and/or propranolol. The IHR in all species decreased progressively with an increase in body weight from young to adult, and moreover the ANT altered toward the direction of parasympathetic predominance by a decrease in sympathetic tone and/or an increase in parasympathetic tone. The decrease of the RHR with growth resulted from a decrease in the IHR primarily and from a parasympathetic predominance in the ANT secondarily. A considerable species difference existed in the alteration of the ANT.

Aging↗
PubMed1989

Influence of autonomic nervous activity on variations in the R-R intervals in adult goats.

We used a heart rate memory apparatus to measure 2047 successive R-R intervals with an accuracy of 10 msec in adult goats. For 100 successive stationary R-R intervals out of the 2047 intervals, the R-R intervals sequence was recorded graphically and the means and standard deviations (SD) were calculated. The magnitude of the variation in the R-R intervals was represented by the SD. The usefulness of the analysis of R-R intervals as an indicator of autonomic nervous activity was determined. The diagram of 100 successive R-R intervals at rest showed a conspicuous periodic fluctuation. After the administration of atropine, atropine plus propranolol or after feeding, the R-R intervals were markedly shortened and the variations in the R-R intervals were abolished. After the administration of propranolol only, the R-R intervals were prolonged and the amplitude of the fluctuations in the R-R intervals was conspicuously increased. The respiration curve and the variation in the R-R intervals at rest fluctuated in periodic synchrony. A positive correlation between the mean and the SD of the R-R intervals was highly significant. This indicates that the variations in the R-R intervals in the adult goats are closely related to autonomic nervous activity and that the analysis of the R-R intervals is suitable for the noninvasive assessment of autonomic nervous activity.

Animals↗
PubMed1989

Expression level of the retinoblastoma susceptibility gene is elevated in simian virus 40-transformed cells.

We examined the level of mRNA of the retinoblastoma-susceptibility gene (Rb gene) in simian virus 40 (SV40)-transformed primate cells. The mRNA level of Rb gene was elevated in SV40-transformed cells compared with that in untransformed parental cells. The level of Rb message was also increased by SV40 infection on monkey kidney CV-1 cells. The level of Rb gene mRNA in SV40-transformed or SV40-infected cells was about fourfold higher than that in controls. These observations suggest that Rb gene is one of the cellular genes which can be elevated by SV40 directly or indirectly.

Antigens, Polyomavirus Transforming↗
PubMed1989

Diagnosis of thyroid mass due to intravenous digital subtraction angiography--does it play an important part in diagnosis of thyroid mass?

33 patients with thyroid mass were studied by intravenous digital subtraction angiography (IV-DSA), thyroid scintigraphy (TS), ultrasonography (US), and computed tomography (CT). The detective rate of lesion by each diagnostic imaging was as follows: IV-DSA 71%, TS 70%, US 94%, and CT 76%. US was the most excellent and most sensitive diagnostic imaging of both benign and malignant lesions. As regards the thyroid cancer by IV-DSA, malignant findings were heterogeneity, an irregular contour, and an unclear contour of tumor stain. Specific diagnostic rate of each imagings was as follows: IV-DSA 88%, TS 100%, US 86%, and CT 75%. US was not so good imaging of a specific diagnosis for the thyroid mass. As regards the thyroid mass, influence of the common carotid artery and the internal jugular vein were investigated by the degree of compression of both vessels on IV-DSA. However IV-DSA could not reveal tumor invasion to these vessels. We learned present the limit of diagnosis of the thyroid mass due to IV-DSA, because IV-DSA was unable to reveal to us exactly information of both a sensitive and a specific diagnosis. We, however, think that IV-DSA is a useful diagnostic imaging as a mapping study which reveals a coronal image of a relationship between the thyroid mass and the common carotid artery and/or the internal jugular vein in surgery.

Adult↗
PubMed1988

78-kilodalton glucose-regulated protein is induced in Rous sarcoma virus-transformed cells independently of glucose deprivation.

To identify mRNAs with altered expression in Rous sarcoma virus (RSV)-transformed cells, we screened a chicken embryo fibroblast (CEF) cDNA library by differential hybridization. One clone, designated R1H, showed markedly elevated mRNA expression in RSV-transformed cells. Nucleotide sequence analysis indicated that R1H mRNA encodes 78-kilodalton glucose-regulated protein (GRP78). Chicken GRP78 was found to be very highly conserved in comparison with rat GRP78 (96% identity between chicken and rat amino acid sequences). In contrast to previous observations, we found that GRP78 was induced in RSV-transformed cells in the absence of glucose deprivation. When cells were grown in glucose-supplemented medium, the level of GRP78 mRNA was approximately fivefold higher in RSV-transformed CEF than in transformation-defective virus-infected or uninfected CEF. Similar changes in GRP78 protein content were also found. Using a temperature-sensitive mutant of RSV and supplemental glucose, we found a gradual increase in the level of GRP78 mRNA beginning at 4 h after shiftdown to permissive temperature. Uridine supplementation did not block the induction seen in CEF infected with a temperature-sensitive mutant. These results indicate that GRP78 is induced by p60v-src in the absence of glucose deprivation.

Animals↗
PubMed1987

Transformation by Rous sarcoma virus induces a novel gene with homology to a mitogenic platelet protein.

A cDNA clone, designated 9E3, was isolated from a chick embryo fibroblast (CEF) cDNA library. 9E3 mRNA was 20-fold higher in CEF following transformation by Rous sarcoma virus because of increased transcription rate. In CEF infected with temperature-sensitive mutants, increased 9E3 mRNA was found within 2 hr of a shift to permissive temperature. Nucleotide sequence and in vitro translation results indicate that 9E3 mRNA encodes an 11 kd polypeptide that is homologous to human connective tissue activating peptide III (CTAP-III), a mitogenic platelet alpha-granule protein, and to beta-thromboglobulin and platelet factor 4. The reported biological activities of CTAP-III suggest that elevated expression of 9E3 may play a role in producing some of the phenotypic features of RSV-transformed cells.

Amino Acid Sequence↗
PubMed1987

Aldosterone biosynthesis and cytochrome P-45011 beta: evidence for two different forms of the enzyme in rats.

Whereas cytochrome P-45011 beta has been recently shown to catalyze the two-step conversion of corticosterone to aldosterone in the bovine and porcine adrenal cortex, the identity of the enzyme involved in the two final steps of aldosterone biosynthesis in the rat adrenal cortex is as yet unknown. Mitochondria from capsular adrenals of sodium-deficient, potassium-replete rats converted corticosterone to 18-hydroxycorticosterone and aldosterone at markedly higher rates than mitochondria from capsular adrenals of sodium-replete, potassium-deficient rats. However, the same preparations exhibited no difference in the 11 beta-hydroxylase activity, i.e. the conversion of deoxycorticosterone to corticosterone. Only mitochondria of zona glomerulosa from rats with stimulated aldosterone biosynthesis contained a 49K protein which showed a strong cross-reactivity with a monoclonal antibody raised against purified bovine cytochrome P-45011 beta. By contrast, a crossreactive protein with a molecular weight of 51K was found in mitochondria of zona fasciculata and in mitochondria of zona glomerulosa from rats with a suppressed aldosterone biosynthesis. These findings indicate the existence of two different forms of cytochrome P-45011 beta in the rat adrenal cortex, with only one of them, i.e. the 49K form, being capable of catalyzing the two final steps of aldosterone biosynthesis in situ.

18-Hydroxycorticosterone↗
PubMed1987

Marked increase in serum alpha-fetoprotein level in cirrhosis: a case report.

A 56-yr-old Japanese man with chronic liver disease was admitted for evaluation of increased serum alpha-fetoprotein reaching levels as high as 7190 ng/ml. The presence of hepatocellular carcinoma was ruled out by computed tomography and hepatic angiography. Laparoscopy and liver biopsy sample showed active liver cirrhosis. alpha-Fetoprotein granules were positive in hepatocytes. The rise in serum alpha-fetoprotein level was transitory and returned to less than 100 ng/ml 4 wk later. It was suggested that regeneration after acute exacerbation of cirrhosis might have been closely related to the dramatic increase in alpha-fetoprotein production.

Chronic Disease↗
PubMed1987

[A case of carcinoma in situ of the renal pelvis].

A case of carcinoma in situ of the renal pelvis in a 70-year-old female is reported. The patient was admitted with the complaints of macrohematuria and left back pain. Urine cytology, which was carried out three times using urine samples collected directly from the urinary bladder proved to be negative. Drip infusion pyelography (DIP) and retrograde pyelography (RP) disclosed stenosis of the left ureter at the level of L3-L4. Selective renal angiography revealed no abnormalities. Based on the DIP and RP findings, the diagnosis of tumor in the left ureter was made, and left total nephroureterectomy with partial cystectomy was performed. The removed kidney showed signs of mild hydronephrosis but no tumor was found macroscopically. The stenosed site of the ureter had scar-like tissue. Microscopic examination revealed that the stenosed ureter consisted of nonspecific granulation tissue but the mucosa of the renal pelvis showed grade III transitional epithelial cell carcinoma, At 24 months after operation, there is no evidence of tumor recurrence, and urine cytology is also negative.

Aged↗