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Biomedical subjects

S Sugano

Publications and source records attributed to S Sugano.

At least 235 records · Page 13Linked to original sources
PubMed1984

Changes of cardiac and respiratory rhythm in non- and tracheostomized rats exposed to nitrogen dioxide.

Cardiac and respiratory changes in non- and tracheostomized rats were examined during exposure to 20 ppm of NO2 for 150 min. The abnormal respiratory pattern consisted of rapid shallow breathing, deep breathing, and apnea, and the bradyarrhythmias were observed in the tracheostomized rats during exposure. Also, similar changes were seen in the nontracheostomized rats. A decrease in the heart rate (HR) was observed in both non- and tracheostomized rats. The decrease in HR was depressed by atropine injection, and the abnormal respiratory patterns were almost abolished by this drug. It was suggested, from these results, that the cardiac and respiratory abnormalities could be induced without the irritation to upper respiratory tracts, and that the vagal efferent pathway had an important role in the appearance of the abnormalities during exposure.

Air Pollutants↗
PubMed1984

Influence of varied [Ca2+]0 and [Na+]0 on slow responses of newborn and adult rat hearts.

The electrophysiological properties of slow responses of rat hearts were investigated in newborn (two-day-old) and adult (few-month-old) rats under conditions of high [K+]0 (25 mM) with isoproterenol (1 X 10(-7)M) using the standard techniques of intracellular microelectrode recording. The potentials of slow responses were measured in varied [Ca2+]0: in adults the peak potential varied linearly with a slope of about 31 mV for a 10-fold change in [Ca2+]0, while in newborns it varied, but not linearly, and showed a positive peak potential in low [Ca2+]0 (0.5 mM). In a low [Na+]0 solution (55% [Na+]0), with constant [Ca2+]0 (2 mM), the peak potential was reduced in newborn hearts, while it was little affected in adult hearts. These results suggest that the peak potential of the slow response depends mainly on [Ca2+]0 in adult rat hearts, while it depends on both [Ca2+]0 and [Na+]0 in newborns.

Action Potentials↗
PubMed1984

Two classes of transformation-deficient, immortalization-positive simian virus 40 mutants constructed by making three-base insertions in the T antigen gene.

We constructed two mutants of simian virus 40 (SV40) by introducing a three-base duplication at AvaII cutting sites within the large T antigen coding region, and we examined these mutants for their abilities to replicate in monkey GC7 cells, to transform rat cell line 3Y1 cells, and to transform and immortalize primary cells from newborn rats. Neither of the mutants could replicate in GC7 cells. One mutant with the duplication at 0.335 SV40 map units (m.u.) (inA942) could transform 3Y1 cells, but the other mutant with the duplication at 0.636 m.u. (inA941) could not. The two mutants could not transform primary rat cells but retained immortalization activity. The results suggest that transformation of primary cells by SV40 requires at least two distinct activities of the large T antigen, one of which can be replaced by a cellular function(s) expressed in immortalized 3Y1 cells.

Animals↗
PubMed1984

[Infectious urachal cyst: a case report].

A case of an infectious urachal cyst that presented as a lower abdominal mass in a 44-year-old man is reported. There was no urinary tract infection. Cystoscopy revealed the dome retracted. All other investigations were normal without microscopic hematuria. Laparotomy revealed the mass attached to the small intestine because of infection. The mass was excised after partial resection of small intestine and partial cystectomy.

Adult↗
PubMed1983

Expression of adenovirus type 12 E1A gene in monkey cells, using a simian virus 40 vector.

Simian virus 40 (SV40) recombinants carrying the adenovirus type 12 E1A gene were constructed. The SV40 expression vector was constructed by removing most of the VP1 gene and an internal part of the intervening sequence for late 16S RNA and by joining the 5' and 3' splice sites into a small segment. The adenovirus type 12 E1A gene with or without its own promoter was inserted downstream from the SV40 late promoter and the splicing junctions. The recombinant DNA was propagated and packaged in monkey cells by cotransfection with an early temperature-sensitive mutant (tsA58) DNA as helper. Immunofluorescent staining of the monkey cells infected with the resulting virus stocks showed that up to 20% of the cells overproduced the E1A gene products in the nuclei. Two-dimensional gel electrophoresis of the products indicated that the products were very similar or identical to the authentic polypeptides synthesized in adenovirus type 12-infected human embryo kidney cells. The E1A mRNA was initiated at the SV40 late promoter irrespective of the presence of the E1A promoter and terminated at either the E1A or the SV40 polyadenylation signal. These hybrid mRNAs were correctly spliced in the E1A coding region.

Adenoviruses, Human↗
PubMed1983

Initiation of simian virus 40 DNA replication in vitro.

Exogenously added simian virus 40 (SV40) DNA can be replicated semiconservatively in vitro by a mixture of a soluble extract of HeLa cell nuclei and the cytoplasm from SV40-infected CosI cells. When cloned DNA was used as a template, the clone containing the SV40 origin of DNA replication was active, but a clone lacking the SV40 origin was inactive. The major products of the in vitro reaction were form I and form II SV40 DNAs and a small amount of form III. DNA synthesis in extracts began at or near the in vivo origin of SV40 DNA synthesis and proceeded bidirectionally. The reaction was inhibited by the addition of anti-large T hamster serum, aphidicolin, or RNase but not by ddNTP. Furthermore, this system was partially reconstituted between HeLa nuclear extract and the semipurified SV40 T antigen instead of the CosI cytoplasm. It is clear from these two systems that the proteins containing SV40 T antigen change the nonspecific repair reaction performed by HeLa nuclear extract alone to the specific semiconservative DNA replication reaction. These results show that these in vitro systems closely resemble SV40 DNA replication in vivo and provide an assay that should be useful for the purification and subsequent characterization of viral and cellular proteins involved in DNA replication.

Antigens, Viral, Tumor↗
PubMed1982

Thallium-201-chloride thyroid scintigraphy to evaluate benign and/or malignant nodules: usefulness of the delayed scan.

The purpose of this study is to evaluate benign and/or malignant thyroid tumors with 201TI thyroid scan. We studied 76 cases of histologically verified thyroid tumors, all seen as cold nodules on the 123I thyroid scan. 201TI thyroid scan was performed 5-15 minutes (early scan) and 3-5 hours (delayed scan) after intravenous administration of 1.5-2.0 mCi of 201TI. In 35 (94.6%) of 36 malignant tumors (anaplastic carcinoma, six; papillary carcinoma 23; follicular carcinoma, five; epidermoid carcinoma, one; malignant lymphoma, 1) 201TI accumulated in the cold nodule of the 123I thyroid scan on both early and delayed scans. On the other hand, the delayed 201TI scan was negative in 35 out of 39 (89.7%) benign tumors. Employing early and delayed 201TI scans, we were able to differentiate most malignant thyroid tumors from those which were benign. False-negative and -positive cases are discussed.

Adult↗
PubMed1980

Association of simian virus 40 T antigen with replicating nucleoprotein complexes of simian virus 40.

An immunoprecipitation assay was established for simian virus 40 T-antigen-bound nucleoprotein complexes by means of precipitation with sera from hamsters bearing simian virus 40-induced tumors. About 80% of simian virus 40 replicating nucleoprotein complexes in various stages of replication were immunoprecipitated. In contrast, less than 21% of mature nucleoprotein complexes were immunoprecipitated. Pulse-chase experiments showed that T antigen was lost from most of the nucleoprotein complexes concurrently with completion of DNA replication. T antigen induced by dl-940, a mutant with a deletion in the region coding for small T antigen, was also associated with most of the replicating nucleoprotein complexes. Once bound with replicating nucleoprotein complexes at the permissive temperature, thermolabile T antigen induced by tsA900 remained associated with the complexes during elongation of the replicating DNA chain at the restrictive temperature. These results suggest that simian virus 40 T antigen (probably large T antigen) associates with nucleoprotein complexes at or before initiation of DNA replication and that the majority of the T antigen dissociates from the nucleoprotein complexes simultaneously with completion of DNA replication.

Antigens, Neoplasm↗
PubMed1980

[The clinical values fro chemical constituents of blood in normal miniature Shiba goats (author's transl)].

Using the both methods. RaBA-Super System (Rapid Blood Analyzer System), the clinical values for chemical constituents of blood in Shiba goats bred in Stock Farm, University of Tokyo, were determined on the following items: total protein, albumin, TTT, glucose, BUN, total bilirubin, total cholesterol, triglyceride, GOT, GPT, ALP, LDH, CPK, cholinesterase, calcium and inorganic phosphorus. The results obtained were summarized as follows: 1) All items determined were to be analyzed by means of the RaBA-Super System, although the values for total cholesterol, TTT, ALP and CPK varied considerably with individuals. 2) The values of adult female goats were significantly higher than those of young ones in total protein and albumin, and lower in glucose, cholinesterase, ALP and CPK. 3) The values of GPT and BUN of adult female goats in summer were significantly lower than those in winter and autumn. 4) The values for triglyceride and albumin of adult female goats using the RaBA-Super System were inconsistent with those analyzed simultaneously by the manual method, but a significant linear correlation was recognized between the both methods.

Age Factors↗