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Biomedical subjects

T Motoyama

Publications and source records attributed to T Motoyama.

At least 19 recordsLinked to original sources
PubMed1992

Functioning ovarian carcinoids induce severe constipation.

Five patients with ovarian carcinoid who had severe constipation for a long period preoperatively showed marked reduction of this symptom postoperatively. Because this phenomenon was believed to be caused by some biologically active substance rather than a mechanical effect of the tumor, reactivity to 17 amine and peptide hormones was studied immunohistochemically in these patients. Numerous peptide YY (PYY)-positive cells were detected, with PYY-positive cells representing more than 50% of all carcinoid tumor cells in each patient. PYY, which has a pharmacologic inhibitory action on intestinal motility, was presumably the cause of the constipation in these patients.

Adult↗
PubMed1992

Three human osteosarcoma cell lines exhibiting different phenotypic expressions.

to elucidate the differences in histological features and biological behavior of osteosarcomas, three human osteoblastic-type osteosarcomas were studied in vitro and in nude mice. The secretory processing and extracellular fiber formation of type I collagen proved to be the most important factor in bone formation in the osteosarcomas. Alkaline phosphatase also seemed to be important. However, we were unable to find any particular protooncogene abnormalities which could have been implicated in the occurrence or biological behavior of these osteosarcomas.

Alkaline Phosphatase↗
PubMed1992

A case of hypersensitivity syndrome resembling Langerhans cell histiocytosis during phenobarbital prophylaxis for convulsion.

The case of a two-year-old girl with generalized histiocytosis, probably induced by phenobarbital, is reported. Symptoms, including intermittent fever, systemic lymphadenopathy, maculopapular skin eruption and hepatosplenomegaly, suggested Langerhans cell histiocytosis. Laboratory examinations revealed leukocytosis with lymphocytosis and eosinophilia and a high LDH serum level, while GOT and GPT were within normal ranges. Cytological studies of lymph node and pleural effusion specimens revealed proliferation and infiltration of Langerhans cell histiocytes with eosinophilia. No histiocyte proliferation was observed in the bone marrow or skin. The clinical manifestations shown by the patient were, however, transient, and improved spontaneously after the discontinuation of phenobarbital. The case was considered to be one of phenobarbital hypersensitivity syndrome based on clinical course and laboratory findings. The mechanism and differential diagnosis of the syndrome are discussed.

Child, Preschool↗
PubMed1991

Relationship between genotypes of longevity genes and developmental speed in Drosophila melanogaster.

Hatching time (the period between egg-laying and hatching) and emerging time were surveyed and their relationship with the adult life span was investigated. A relationship between emerging time and adult life span was clearly evident: early emergers were often long-lived. This relation is considered to have a genetic basis because all the larvae in a group were bred in the same culture bottle. Thus, the longevity genes involved also appear to have control over the rate of development. No significant relation was observed between hatching time and adult life span or between hatching time and emerging time. These results suggest that the function of the longevity genes begins at the larval or pupal stage before emergence, and that adult life spans differentiate at this time.

Animals↗
PubMed1991

Cytoplasmic influence on the expression of nuclear genes affecting life span in Drosophila melanogaster.

In earlier studies we have found that the difference between short and long life spans of two inbred strains of Drosophila melanogaster is controlled by nuclear major genes. The present study has revealed a cytoplasmic factor that influences the expression of the nuclear longevity genes. The factor shows a typical maternal inheritance and is considered to be an extranuclear gene, such as mitochondrial DNA (chondriome). This paper marks the discovery of two basic forms of inheritance, nuclear and extra-nuclear, in the genetics of life span of D. melanogaster. These findings suggest that further studies, including genetic engineering, on longevity and aging might enable direct manipulation of these characters.

Animals↗
PubMed1991

Establishment of clonal cell lines, with or without cartilage phenotypes, from a hamster mesenchymal chondrosarcoma.

A hamster mesenchymal chondrosarcoma was found in the soft tissues of the cheek pouch and has been successfully transplanted. The tumor was composed principally of two cell types: poorly differentiated mesenchymal cells and focal areas of cells in islands showing cartilaginous differentiation. The clonal cell lines, MCS-1 and MCS-8 which closely correspond to the respective cell types in the original tumor were also established. MCS-1 cells formed an undifferentiated sarcoma in the subcutaneous layer of nude mice and MCS-8 cells formed a chondrosarcoma of a common type.

Animals↗
PubMed1990

Cancer antigen 125, carcinoembryonic antigen, and carbohydrate determinant 19-9 in ovarian tumors.

The authors studied data of combination assays of tumor markers, because simultaneous elevation of different types of tumor markers in the serum was puzzling. They interpreted such phenomena regarding cancer antigen 125, carcinoembryonic antigen, and carbohydrate determinant 19-9 in ovarian tumors. The tissue expression of the antigens was compared with preoperative serum levels. Several different factors were found to cause the simultaneous elevation of two or three of these markers in the serum. Furthermore, even when the levels of some of the tumor markers were raised in the serum, the ovarian tumor did not always produce the marker by itself. This study indicates that immunohistochemical identification of a marker in tumor tissue is prerequisite to the use of that marker in the serum to monitor disease status.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1990

Influence of temperature on the inheritance of adult life span in Drosophila melanogaster.

Mating experiments were performed at 27 degrees C, 22 degrees C, and 17 degrees C, to investigate the inheritance of adult life span of highly inbred strains of Drosophila melanogaster. Effects of temperature difference were quantitatively analyzed at the genotypic level. In the temperature range of 17-27 degrees C the autosomal longevity alleles, A1 and A2, exerted major effects. Their effects produced longer life spans as the temperature decreased. The sex-linked longevity alleles, X1 and X2, played a secondary role in influencing life span, and they displayed different effects at different temperatures. Each genotype showed correspondence to the life span expected from the combinations of these longevity genes at the respective temperatures. The genetic loci controlling life span in these inbred strains were named JmA and JmX from "Ju-myo" which means life span or longevity in Japanese.

Animals↗
PubMed1990

Collagen species in various sized human arteries and their changes with intimal proliferation.

The collagen types extracted from intermediate and small sized human arteries were investigated by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) after differential salt fractionation. Limited and repeated pepsin digestion was used to prepare collagen species. Type V, IV and VI collagens were extracted greater in the former relative to in the latter, whereas type I and III collagen were extracted until the last extract. Type I collagen comprised as the major collagen in the intima of various arteries as well as in venous tissue. Type III and V collagens were found to be less in small arteries than in the initial stage of atherosclerosis. Type VI collagen in the intermediate and small arteries was detected on SDS-PAGE.

Adult↗
PubMed1990

[A case of retroperitoneal mucinous cystadenocarcinoma].

We reported is the histogenesis of a case of a primary retroperitoneal cystadenocarcinoma that was resected surgically in a 42-year-old woman who was admitted to hospital for SLE. On echographic examination, she was found to have a right abdominal tumor and underwent an operation for the complete removal of an abdominal tumor located in the right retroperitoneal cavity. A histological examination of the tumor revealed it to be compatible with a mucinous cystadenocarcinoma of the ovary. Only four cases of a primary retroperitoneal mucinous cystadenocarcinoma have been reported in the literature. This rare lesion was studied histopathologically and its histogenesis is discussed.

Adult↗
PubMed1989

Synergistic inhibition of oxidation in dispersed phosphatidylcholine liposomes by a combination of vitamin E and cysteine.

Oxidations of soybean phosphatidylcholine liposomes in an aqueous dispersion initiated by free radicals generated initially either in the aqueous phase or in the lipid phase were efficiently suppressed by vitamin E in the membranes. Vitamin E was consumed linearly with time and, when the inhibition period was over the oxidation proceeded rapidly at a rate similar to that in the absence of vitamin E. L-Cysteine was also effective by itself in scavenging radicals in the aqueous region, but it was consumed more rapidly than vitamin E. On the other hand, cysteine could not scavenge the radicals efficiently in a lipid region. Nevertheless, when vitamin E was incorporated into liposomes, the addition of cysteine in the aqueous phase prolonged the inhibition period and it reduced the rate of decay of vitamin E markedly even when the radicals were generated initially in the lipid bilayer. Furthermore, it was found by an electron spin resonance study that chromanoxyl radical disappeared quite rapidly when it was mixed with cysteine and that the spin adduct of cysteine radical was observed in the presence of alpha-(4-pyridyl-N-oxide)-N-tert-butyl nitrone. It was concluded that L-cysteine located in an aqueous region could regenerate vitamin E by reacting with vitamin E radical formed in a lipid region and show a synergistic antioxidant effect, although its efficiency of vitamin E regeneration was lower than that by vitamin C.

Antioxidants↗
PubMed1989

Experimental chemotherapy and radiotherapy to paratesticular rhabdomyosarcoma.

Experimental chemotherapy and radiotherapy were tried in transplanted tumors derived from a paratesticular embryonal rhabdomyosarcoma. There was no significant difference on the therapeutic effect between a combination chemotherapy composed of vincristine, actinomycin D and cyclophosphamide, so-called "VAC" regimen, and a single therapy of radiation. However, morphologic analyses suggest that VAC is effective in embryonal rhabdomyosarcomas in which undifferentiated rhabdomyoblasts predominate, while radiotherapy is preferable for those containing variously differentiated rhabdomyoblasts.

Adolescent↗
PubMed1989

Placental alkaline phosphatase-like isoenzymes produced by human gastric cancer cells.

The human gastric cancer cell lines, MKN1 and SCH, were biochemically and biologically characterized according to the monophenotypic expression of placental alkaline phosphatase (PLAP)-like enzymes. The MKN1 cell line, derived from adenosquamous carcinoma, showed the same enzyme properties as the Regan isoenzyme, whereas the SCH cell line, derived from primary gastric choriocarcinoma, had properties identical with the Nagao isoenzyme. Regan isoenzyme activity expressed by MKN1 cells was stimulated by glucocorticoid and suppressed by retinoic acid. Both agents had no significant effect on SCH cells. On the other hand, Nagao isoenzyme activity expressed by SCH cells was stimulated by sodium butyrate, which had no stimulatory effect on MKN1 cells. Moreover, the PLAP-like activity of MKN1 cells showed no observable relationship to human chorionic gonadotropin (hCG)-producibility. Whereas expression of the Nagao isoenzyme by the SCH cell line is presumably a result of functional differentiation in the trophoblastic direction, that of the Regan isoenzyme by the MKN1 cell line is probably not. Perhaps the Regan isoenzyme is related to carcinogenesis.

Adenocarcinoma↗
PubMed1989

Mode of inheritance of major genes controlling life span differences between two inbred strains of Drosophila melanogaster.

Although life span is generally considered to be under polygenic control, we obtained experimental evidence of Mendelian genes exerting major effects on life span differences between two inbred strains of Drosophila melanogaster. Our data indicate two loci with major effects, one being autosomal and the other sex-linked. The alleles at the autosomal locus are designated A1 and A2, the latter producing longer life. Heterozygotes, A1A2, exhibit over-dominance. The alleles at the sex-linked locus, designated X1 and X2, produce life-extending effects. X1 revealed a dosage effect, causing homozygous females to live longer than hemizygous males; X2 showed no dosage effect. The identified genes are considered to control the period of activity of many genes maintaining life.

Animals↗
PubMed1989

Oral magnesium supplementation in patients with essential hypertension.

To elucidate the effects of magnesium on high blood pressure, a 4-week study of oral magnesium supplementation (MgO 1 g/day) was conducted in 21 outpatients with uncomplicated essential hypertension. During the study, blood pressure and intraerythrocyte sodium concentration decreased significantly, and the erythrocyte ouabain-sensitive 22Na efflux rate constant (Kos) and intraerythrocyte magnesium concentration both increased. Serum triglyceride and free fatty acid concentrations were reduced. Furthermore, the elevation in Kos significantly and positively correlated with both the increase in intraerythrocyte magnesium concentration and the decrease in mean blood pressure. There was a significant inverse correlation between the prestudy Kos and the decrease in mean blood pressure. In addition, when patients were divided according to their overall decrease in mean blood pressure, the prestudy intraerythrocyte sodium concentration was significantly higher in patients with a mean blood pressure decrease of more than 7 mm Hg than that of patients whose mean blood pressure decrease was less than 7 mm Hg. These results suggest that oral magnesium supplementation may lower blood pressure through the activation of a cell membrane sodium pump and may reduce serum lipid concentration. It also suggests that the lower the prestudy Kos or the higher the prestudy intraerythrocyte sodium concentration, the more effective the oral magnesium treatment is in lowering blood pressure. Therefore, we concluded that appropriate oral magnesium intake might be effective as a nonpharmacological treatment for essential hypertension.

Administration, Oral↗
PubMed1989

Climatic adaptation in thermogenesis and thermal insulation in wood mice (Apodemus argenteus).

Wood mice (Apodemus argenteus) were trapped live at three different altitudes (below 1,000, 1,900, and 2,400 m) during a 1-year period (Feb. 1984-Jan. 1985). After remaining at the trapped locations for 10-14 days, they were transferred into a climatic chamber at an altitude of 610 m. Oxygen consumption (VO2) and colonic temperature (Tco) were measured at chamber temperatures (Ta) of five steps (30, 20, 10, 0, and -10 degrees C) in freely moving conditions. In response to Ta of 0 degrees C for the mice trapped in winter when their mean local habitat temperature (Te) were lower than 0 degrees C, there was a significant inverse correlation between VO2 and Te (r = -0.70, p less than 0.001) whereas no significant correlation (r = 0.23) was observed in the mice trapped in other seasons when Te was higher than 0 degrees C. The correlation between Tco and Te was significant (r = -0.66, p less than 0.001) over the entire range of Te. The pelt weight of the mice trapped at Te higher than 0 degrees C had a significant inverse correlation with Te (r = -0.65, p less than 0.001), but not in the mice trapped at Te lower than 0 degrees C. After measurement of VO2 and Tco at Ta of 0 degrees C, the mice who had lived in colder habitats (below 0 degrees C) showed 0% mortality, whereas the mortality of the populations which had lived in warmer habitats was 13%. These results suggest that, in wood mice, adaptation to severe cold is established by an enhanced thermogenesis and by an increased insulation of the pelt in moderate cold.

Adaptation, Physiological↗