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Biomedical subjects

S Sakamoto

Publications and source records attributed to S Sakamoto.

At least 631 records · Page 35Linked to original sources
PubMed1986

Thymidylate synthetase and thymidine kinase activities in DMH-induced colon carcinomas in rats and effects of UFT.

Carcinoma of the colon was induced in rats by injection of a carcinogen 1,2-dimethylhydrazine (DMH), and thymidylate synthetase (TS) and thymidine kinase (TK) activities, which catalyze the biosynthesis of dTMP by the de novo pathway and the salvage pathway of pyrimidine synthesis, respectively, were measured in normal control colon, DMH-treated normal colon, and DMH-induced colon carcinoma with or without administration of two doses of an anti-cancer drug UFT (a combination of tegafur and uracil). TS and TK activities were both increased after treatment with DMH, markedly in colon carcinoma tissue, and to a lesser degree in normal-appearing colon tissue. This phenomenon is well explained by the hypothesis that biochemical alterations of DNA-synthesizing enzyme activities occur as a preliminary step prior to the development of overt cancerous transformation. A low dose of UFT inhibited TS activity but enhanced TK activity, therefore, the salvage pathway may compensate for the reduced level of the de novo synthesis. On the other hand, a large dose of UFT reduced both TS and TK activities, perhaps due to cytotoxic effects of UFT incorporation into RNA.

1,2-Dimethylhydrazine↗
PubMed1986

[A case of complete remission from acute myelogenous leukemia in second relapse achieved using an intermediate-dose cytosine arabinoside (ID Ara-C) regimen].

A 57-year-old-male patient with acute myelogenous leukemia in second relapse who was refractory to BHAC . AMP [behenoyl arabinosyl cytosine (BHAC), aclacinomycin, 6-mercaptopurine and prednisolone (PSL)] and BHAC . DVP [BHAC, daunomycin, vincristine and PSL] was treated with an intermediate-dose cytosine arabinoside (ID Ara-C) regimen. This schedule consisted of a 1-h infusion of Ara-C at a dose of 500 mg/m2 every 12 h for 6 d (days 3-8), in combination with doxorubicin 50 mg/m2 on day 1 and vincristine 1 mg/m2 on day 2. The patient achieved a complete remission 23 days after completion of Ara-C and was treated with ID Ara-C (Ara-C days 3-6) as a consolidation. Remission duration was only 2.5 months. Plasma Ara-C concentrations were assayed by HPLC and the peak level was 6.7 micrograms/ml. Side effects were mild nausea, vomiting, alopecia and moderate skin rash.

Cytarabine↗
PubMed1986

[A case of intrascrotal pseudocyst].

A 37-year-old male visited our hospital with the chief complaint of a mass about the size of a hens egg in the right scrotum. Before hospitalization, he had noticed the abnormal intrascrotal mass. The mass gradually enlarged with pain, so he was admitted on May 23, 1982. Under the diagnosis of intrascrotal tumor, the mass was removed. It was a cyst with enriched geratinoid contents enclosed with thick granulation tissue and adhered to the tunica vaginalis externally. Pathological findings revealed it to be an intrascrotal pseudocyst. Discussion is made in relation to the histological genesis of this lesion.

Adult↗
PubMed1986

[Analysis of ventricular wall motion using multislice ECG-gated cardiac X-ray CT: application of the three-dimensional reconstruction technique].

A new computer system was proposed to evaluate abnormal motion of the ventricular wall in patients with myocardial infarction. Multi-slice ECG-gated cardiac X-ray CT (MSECT), a new technique developed in our laboratory, was the source of the original image. Using this system, we reconstructed three-dimensional images, calculated % shortening values of the entire heart, and visualized abnormal wall motion on the ventricular surface, displaying three-dimensionally. Our initial study of five patients with myocardial infarction showed good correlation between the findings using this system and conventional echocardiography and cine-ventriculography. Since the development of the ECG-gated method, the application of CT to the study of heart diseases has progressed rapidly. In patients with myocardial infarction, ECG-gated cardiac CT is used to visualize infarcted myocardium and to evaluate impaired cardiac function. However, such analyses were limited to single slices, because a large dose of contrast medium was required to distinguish the ventricular chamber from the myocardium. By adopting multi-slice ECG-gated cardiac X-ray CT images as the data source and using three-dimensional reconstruction technique, this system is useful for evaluating abnormal wall motion.

Adult↗
PubMed1986

Idiopathic fatty liver of pregnancy with a subsequent uncomplicated pregnancy and a progressive increase in serum cholinesterase activity during the third trimester. A case report.

We treated a patient with idiopathic fatty liver of pregnancy and a subsequent uncomplicated pregnancy. She experienced general fatigue, nausea, vomiting and jaundice, and renal failure occurred in the third trimester of her first pregnancy. Liver biopsy revealed swollen hepatocytes with microvesicular changes in the cytoplasm. A diagnosis of idiopathic fatty liver of pregnancy was made. Following delivery of a dead fetus, she recovered completely and was discharged on the 30th hospital day. Eighteen months later, she became pregnant again and was delivered of a healthy male baby in the 39th week of gestation. Total bilirubin and transaminase levels were normal, and renal function tests revealed no significant changes during the course of the pregnancy. However, cholinesterase activity increased progressively from the 7th month, thereby suggesting a predisposition to idiopathic fatty liver of pregnancy.

Adult↗
PubMed1985

Collagenase synthesis in clonal rabbit odontoblast-like cells (RP cells).

Post-confluent cultures of cloned rabbit odontoblast-like cells (RP: Rabbit Pulp cells) produced latent collagenase, which was isolated from serum-containing culture media by heparin-Sepharose affinity chromatography. RP collagenase was purified 4,420-fold from serum-containing medium to a specific activity of 1,313 units/mg with a yield of 14% by heparin-Sepharose affinity chromatography, carboxymethyl-cellulose ion-exchange chromatography, and by immunoadsorption chromatography. The RP cell culture appears to be a suitable model to use for studying collagenase synthesis in mineralized tissue-forming cells and for elucidating the mechanism of collagen degradation in pulp tissue and dentin matrix.

Animals↗
PubMed1985

Different recovery process of ST depression on postexercise electrocardiograms in women in standing and supine positions.

False-positive exercise test responses are frequently observed in women. To differentiate a false-positive from a true-positive test response, the effect of postures for recording a postexercise electrocardiogram to the recovery process of ST depression was investigated in 26 women with nonischemic ST depression and in 14 patients with typical angina pectoris. Exercise tests were performed twice, and the postexercise electrocardiogram was recorded while standing during the first test and in the supine position during the second test. In the false-positive test, maximal ST depression occurred immediately after exercise and showed a rapid recovery process in the early recovery phase. However, ST depression persisted without complete recovery, or increased in the late recovery phase as long as subjects were kept standing. In contrast, ST depression returned to the control level when subjects changed to the supine position after exercising. This discrepant pattern in the recovery process of ST depression by changing postures was not observed in the true-positive test results. Changing postures for recording postexercise electrocardiograms could be helpful in differentiating a false-positive response from a true ischemic response.

Adult↗
PubMed1985

Long arm deletion of chromosome 5 in a case of chronic myelomonocytic leukemia.

The 46,XY,del(5)(q31),del(12)(p11) and 46,X,-Y,del(5)(q31),del(12)(p11), +mar clones were found in the bone marrow cells of a 64-year-old Japanese man with chronic myelomonocytic leukemia (CMML). Although the 5q- anomaly has been reported to occur in various hematologic disorders, a literature survey of CMML cases revealed that the present case is the first instance of CMML with the 5q- anomaly. The possible significance of the chromosome findings is discussed.

Bone Marrow↗
PubMed1985

Characterization of a 1980-swine recombinant influenza virus possessing H1 hemagglutinin and N2 neuraminidase similar to that of the earliest Hong Kong (H3N2) virus.

A recombinant (H1N2, formerly Hsw 1N2), A/swine/Ehime/1/80 was found to possess antigenic, biological and genomic characteristics different from those of a previous A/swine/Kanagawa/2/78 (H1N2) strain. Five monoclonal antibodies to A/NJ/8/76 definitely differentiated the hemagglutinin molecules of the former virus from the latter, showing that these viruses differed, at least, at two antigenic determinants. Neuraminidase-inhibition tests with monoclonal antibodies to different H2N2 and H3N2 viruses revealed that the A/swine/Ehime/1/80 strain contained a neuraminidase very similar to that of the late human Asian (H2N2) and the earliest Hong Kong (H3N2) viruses. Growth comparison of swine and human isolates indicated that A/swine/Ehime/1/80 and A/swine/Shizuoka/1/78 (H1N1) failed to grow at 42 degrees C, while A/swine/Kanagawa/2/78 and its possible parental virus, A/swine/Kanagawa/4/78 (H1N1) replicated efficiently at this stringent temperature. These results revealed that the viruses having growth characteristics similar to those of avian influenza virus were present in the swine population. RNA analysis by oligonucleotide mapping suggested that A/swine/Ehime/1/80 may be a recombinant between A/swine/Shizuoka/1/78-like and A/Aichi/2/68 (H3N2)-like viruses. To further determine the gene constellation of this recombinant virus, DNA-RNA hybridization was performed by using DNA segments complementary for swine (H1N1) virus RNA and the entire RNAs of three viruses. The molecular hybridization could define the genomic composition of the recombinant, indicating that only the neuraminidase gene of this virus is derived from the earliest Hong Kong (H3N2)-like virus and remaining seven genes from swine (H1N1) virus.

Animals↗
PubMed1985

Characteristics of a swine recombinant influenza virus isolated in 1980: recombination between swine and the earliest Hong Kong (H3N2) viruses.

A recombinant (H1N2, formerly Hsw1N2), A/swine/Ehime/1/80 was found to possess antigenic biological and genomic characteristics different from those of a previous A/swine/Kanagawa/2/78 (H1N2) strain. Five monoclonal antibodies to A/NJ/8/76 differentiated the haemagglutinin molecules of the former virus from the latter, showing that these viruses differed at two-antigenic determinants at least. Immuno-double diffusion tests with antisera to the isolated neuraminidase and neuraminidase-inhibition tests with monoclonal antibodies to different H2N2 and H3N2 viruses revealed that A/swine/Ehime/1/80 strain contained a neuraminidase subunit very similar to that of late human Asian (H2N2) and the earliest Hong Kong (H3N2) viruses. RNA analysis by oligonucleotide mapping suggested that A/swine/Ehime/1/80 may be a recombinant between A/swine/Shizuoka/1/78-like and A/Aichi/2/68 (H3N2)-like viruses. To determine further the gene constellation of this recombinant virus, DNA-RNA hybridizations were performed using DNA segments complementary for swine (H1N1) virus RNA and the entire RNA of three viruses. The molecular hybridization could define the genomic composition of the recombinant, indicating that only the neuraminidase gene of this virus is derived from the earliest Hong Kong (H3N2)-like virus and remaining seven genes are derived from swine (H1N1) virus.

Animals↗