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Biomedical subjects

H Ohta

Publications and source records attributed to H Ohta.

At least 757 records · Page 42Linked to original sources
PubMed1984

Involvement of hypothalamic vasoactive intestinal polypeptide (VIP) in prolactin secretion induced by serotonin in rats.

To study the possible involvement of hypothalamic vasoactive intestinal polypeptide (VIP) in regulating the secretion of prolactin (PRL), the effect of anti-VIP rabbit serum on serotonin (5-HT)-induced PRL release was examined in urethane-anesthetized male rats. Anti-VIP serum (AVS) or normal rabbit serum (NRS) was infused into a single hypophysial portal vessel of the rat for 40 min at a rate of 2 microliters/min with the aid of a fine glass cannula and 5-HT was injected into a lateral ventricle 10 min after the start of the infusion. Intraventricular injection of 5-HT (10 micrograms/rat) caused an increase in plasma PRL levels in control animals infused with NRS and 5-HT-induced PRL release was blunted in animals infused with AVS (mean +/- SE peak plasma PRL: 118.9 +/- 19.8 ng/ml vs 54.7 +/- 16.2 ng/ml, p less than 0.05). These findings suggest that the secretion of PRL induced by 5-HT is mediated, at least in part, by hypothalamic VIP release into the hypophysial portal blood in the rat.

Animals↗
PubMed1984

[Biochemical studies on alkaline phosphatase isoenzyme profile in endometrial cancer].

Heat-stable ALP has been attracting attention as one of the oncodevelopmental proteins. ALP are now subdivided by biochemical methods into three major groups e.g. tissue-unspecific, intestinal and term placental isoenzymes. Furthermore, term placental ALP in cancer is classified into L-leucine insensitive-Regan and L-leucine sensitive-Nagao isoenzymes. In this paper, we report ALP isoenzyme profiles of normal endometrium and endometrial cancers. 21 cases of normal endometrium and 11 cases of endometrial cancer were examined, and the ALP activity of their butanol extracts was measured by Fishman's method. To identify the ALP isoenzyme pattern, biochemical methods such as 65 degrees C heat-treatment and amino acid inhibition tests were carried out. Most of the ALP in both normal endometrium and endometrial cancers showed biochemical characteristics of tissue-unspecific ALP isoenzyme. A very small amount of term placental isoenzyme was found in normal endometrium. In endometrial cancers, term placental isoenzyme was often found at a higher level than in normal endometrium. Nagao isoenzyme was also found to emerge in a few endometrial cancer cases. From these data it was suggested that the ALP isoenzyme of endometrium underwent a change and "enzyme deviation" occurred during the course of endometrial carcinogenesis and that the ALP isoenzyme deviation might have occurred due to a change in ALP isoenzyme gene expression accompanying cancerous change.

Alkaline Phosphatase↗
PubMed1984

[Shift of placental alkaline phosphatase isoenzymes in the course of pregnancy].

It is generally accepted that every placental protein shows its characteristics vicissitude pattern during pregnancy and that alkaline phosphatases (ALP) are subdivided into three kinds of isoenzymes, i.e.: tissue-unspecific, intestinal and termplacental ALPs. In this study, the changes in ALP isoenzyme profile throughout the course of pregnancy was studied by biochemistry, enzyme- and immuno-histochemistry, and the following results were obtained. In early pregnancy, ALP activity was composed mostly of tissue-unspecific ALP isoenzyme, and its activity revealed a peak value around 10 weeks of pregnancy as in the case of the hCG serum concentration. At the end of the second trimester of pregnancy, instead of tissue-unspecific isoenzyme, ALP activity was mainly composed of term placental ALP isoenzyme, but a very small amount of the isoenzyme was proved to exist in the villi at the 6th week of gestation. The above results were confirmed by morphological studies such as enzyme-cytochemistry and immuno-cytochemistry. It was therefore concluded that at least two genes of ALP isoenzymes existed in the villi and that the regulation of gene activity changed during the course of pregnancy. Furthermore, since tissue-unspecific ALP isoenzyme showed a pattern of change similar to that of serum hCG, the existence of a developmental phase-specific gene set was postulated.

Alkaline Phosphatase↗
PubMed1984

A new imaging agent for medullary carcinoma of the thyroid.

Thyroid scintigraphy, using 99mTc(V) dimercaptosuccinic acid, was performed in four patients with pathologically confirmed medullary thyroid carcinoma and elevated serum calcitonin values. Significant uptake of the tracer was found in the clinically palpable cervical tumor masses, metastatic sites, and residual tumor. This finding, probably specific for medullary thyroid carcinoma, could be of great use in the diagnosis and the surgical follow-up.

Adenocarcinoma↗
PubMed1984

Lysis of horse red blood cells mediated by antibody-independent activation of the alternative pathway of chicken complement.

Horse red blood cells (HRBC) were found to be lysed when incubated with fresh normal chicken serum (NCS). By comparison of the properties of the lysis of HRBC with those of the complement-dependent lysis of sheep red blood cells (SRBC) sensitized with haemolytic antibody via the classical pathway, the following differences were observed between the two haemolytic phenomena. (i) The lysis of HRBC was independent on antibody in contrast to the antibody dependence of the lysis of sensitized SRBC. (ii) The lysis of HRBC was dependent on Mg but not on Ca ion, whereas the lysis of sensitized SRBC required both Mg and Ca ions. (iii) Treatment of NCS with carrageenan that acts as an inactivator of the first component of complement (C1) inhibited the lysis of sensitized SRBC but not the lysis of HRBC. (iv) C1 was consumed in the lysis of sensitized SRBC but not in the lysis of HRBC. (v) Cobra venom factor (CVF), C3 inactivator via the alternative complement pathway, inhibited the lysis of HRBC but not the lysis of sensitized SRBC. (vi) Minimal reaction times for the lysis of HRBC and for the lysis of sensitized SRBC were 90 and 60 min, respectively. These findings indicate that the lysis of HRBC was caused by the antibody-independent activation of complement via the alternative pathway.

Animals↗
PubMed1984

[A newly established melanoma cell line (GAK) with 5-S-cysteinyldopa phenotype].

The production of 5-S-cysteinyldopa by a newly established melanoma cell line GAK is reported. The cell line was derived from a metastatic inguinal lymph node of vulvar malignant melanoma. The cell line grew well without interruption for over 4 years, GAK cells were proved to have melanin granules and tyrosinase activity in their cytoplasma by Masson's staining and dopa reaction, respectively. Melanin granules were ultrastructually identified as melanosomes in various maturing stages. The chromosomal number varied widely and showed aneuploidly, but the modal chromosomal number was stable in the hypotriploid range. GAK cells were transplanted to nude mice and produced tumors resembling the original. Because glucose-6-phosphate dehydrogenase of GAK revealed a type B (slow) mobility pattern on electrophoresis, the possibility of Hela cell contamination could be completely excluded. High performance liquid chromatography revealed "5-S-cysteinyldopa", a new tumor marker of malignant melanoma, in culture media of GAK cells. The cell line described may serve as a representative model system for basic and clinical studies on malignant melanoma.

Aged↗
PubMed1984

Endoscopic intramural injection of anti-neoplastic emulsion.

With the aim of establishing a topical chemotherapy against stomach carcinoma, 5-fluorouracil (5-FU) emulsion (oil/water type) for injection has been developed. The drug distribution was analyzed by 5-FU bioassay and radiographic examination of soft parts, for which radiopaque Lipiodol was employed in an oil phase. In order to examine local toxicity, tissue retention, and transfer to lymph nodes of 5-FU emulsion, the drug was administered perorally to rats and injected intramurally through the gastric serosa into laparotomized dogs. Following this series of experiments, which gave satisfactory results, the time courses of drug concentration in the gastric wall and regional lymph nodes were studied as a pre-clinical trial, by applying endoscopic intramural injection of 5-FU emulsion or solution in dogs. The anti-metastatic and anti-neoplastic effects of 5-FU emulsion were investigated in an experimental model of lymph node metastasis in mice. The emulsion was more effective in subduing metastasis and tumor growth than the solution, and the effectiveness of the former was further augmented by the use of repeated injections rather than a single injection. This method of endoscopic injection of 5-FU emulsion should be of great value as a local therapeutic measure against stomach carcinoma itself as well as against metastatic lesions in the lymph nodes.

Administration, Oral↗
PubMed1984

Beneficial effect of taurine on congestive heart failure induced by chronic aortic regurgitation in rabbits.

Taurine (2-aminoethanesulfonic acid) is known to have a cardiotonic action. The present study was designed to see whether oral treatment with taurine could improve the status of congestive heart failure induced by aortic regurgitation. Nine rabbits were treated daily with taurine (100 mg/kg) after producing aortic regurgitation. Cumulative mortality at 8 weeks in the non-treated group was 52% compared with 11% in the taurine-treated group (p less than 0.05). Cardiac function (max dP/dt) was significantly decreased in rabbits with aortic regurgitation, whereas in taurine-treated rabbits, cardiac function was maintained the same as control. The present data suggest that taurine prevented the rapid progress of heart failure, and consequently prolonged the life expectancy.

Animals↗
PubMed1984

[Studies on carcinoma of the remnant stomach after distal gastrectomy].

Sixty-one patients with carcinoma of the remnant stomach after distal gastrectomy were admitted by the end of 1982. Twenty-six of them were gastrectomized for benign disease such as peptic ulcer and 35 for malignant disease such as gastric carcinoma. The age of the benign group was 58, and the average interval from the first operation was 19 years. The corresponding figures for the malignant group were 63 and 8 years, respectively. In the malignant group, the methods of anastomosis at the first operation were 18 cases of Billroth-I (B-I) and 17 of B-II. The lesion was located at the surgical stump in 7 patients and distant from the stump in 14 patients in this group. In the benign group, there were 10 cases of B-I and 16 of B-II, and no differences were seen in the location. Early carcinoma was noted in 11 patients, and 34 were advanced. Differentiated adenocarcinoma was observed in 25 cases and undifferentiated in 20 in the resected specimen. Although no metastases were seen in early cases, the rate of lymph node metastasis was 70%, and the five-year survival rate was 21% in advanced cases, and 80% in early cases.

Adult↗
PubMed1984

[Biological properties of two newly established cell lines (SKG-3a,3b) from a human uterine cervical epidermoid carcinoma].

This is an initial descriptive report of two morphologically different cell lines (SKG-3a and SKG-3b) obtained from a human uterine cervical epidermoid carcinoma. These sublines were found to be derived from a moderately differentiated epidermoid carcinoma partially mixed with clear cell components. Both sublines had already been subcultivated more than 80 times since the initial separation. SKG-3a cells were much smaller in size and volume than 3b. The numbers of chromosomes were almost identical. Their cytology revealed anaplastic and pleomorphic features. SKG-3a was positive with periodic acid-Schiff stain and this changed to negative after an amylase digestive test, suggesting that the cells contained glycogen. An electron-microscopic examination confirmed the presence of many glycogen particles in 3a cytoplasm, but few in 3b. Tonofilaments and desmosomes were observed in both cytoplasms, suggesting epidermoid origin. In nude mice, SKG-3a produced clear cell epidermoid carcinoma with much glycogen, while 3b grew as a moderately differentiated epidermoid carcinoma with little glycogen. It is concluded that SKG-3a is derived from the clear cell epidermoid carcinoma and 3b is from the moderately differentiated epidermoid carcinoma. It is also clear that both were more heat sensitive at and over 39 degrees C than normal cells.

Adult↗