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Biomedical subjects

J Sato

Publications and source records attributed to J Sato.

At least 343 records · Page 19Linked to original sources
PubMed1989

Effects of chemotherapeutic agents on alpha-fetoprotein secretion and growth of human hepatoma cell lines in vitro.

The effects of various chemotherapeutic agents on alpha-fetoprotein (AFP) secretion and growth of human hepatocellular carcinoma and hepatoblastoma cell lines were investigated in vitro. It was found that there was a high correlation between hepatoma cell number and AFP secretion after treatment and that the amount of AFP secreted per cell per 72 h was not affected with therapeutically achievable concentrations. These results suggest that serum AFP level in patients with hepatomas does not correlate with the size of whole tumour but with that of viable tumour mass, and that AFP-secreting capacity of tumour cells in the mass is kept unchanged after chemotherapy.

Antineoplastic Agents↗
PubMed1989

Measurement of alveolar pressure in closed-chest dogs during flow interruption.

We have developed a technique for installing alveolar capsules in dogs with intact chest wall, by exposing a region of parietal pleura between a pair of ribs and gluing the parietal and visceral pleura together around a small region of lung. This allows the direct measurement of alveolar pressure during spontaneous breathing. We measured alveolar pressure in normal dogs using this technique while suddenly interrupting flow at the trachea during passive expiration. Tracheal pressure exhibited a very rapid rise immediately on interruption that we showed to be composed of two distinct and roughly equal parts: one was the resistive pressure drop across the airways, and the other was a resistive pressure drop across tissues. By simultaneously measuring pleural pressure we showed that the tissues responsible were only in the chest wall and not in the lungs.

Airway Resistance↗
PubMed1989

Effects of ionic calcium on the responses of canine testicular polymodal receptors to algesic substances.

1. To explore possible mechanisms of the responses to algesic substances (bradykinin, hypertonic saline, and high K+ solution) of polymodal receptors in the canine testis, the Ca2+ concentration was varied in vitro. 2. After 1 min in Ca2+-free media, the responses to both high K+ solution (60 mM K+) and hypertonic saline (0.6 M Na+) were significantly augmented and tended to increase further with time; return to normal Ca2+ concentration quickly reversed these changes. These augmenting effects were blocked by the substitution of Mg2+ for Ca2+. The excitation produced by 60 mM K+ was decreased by increasing Ca2+ in a concentration-dependent fashion. 3. Reducing the bath concentration of K+ decreased responses evoked by 9 X 10(-8) M bradykinin (BK), whereas increased K+ concentration had the opposite effect. 4. The excitatory effects of BK were significantly suppressed in extracellular Ca2+-free condition. The suppression was not affected by the addition of Mg2+. Prostaglandin E2, which has been known to be released by BK and to augment the BK response, failed to restore the suppressed response by either preapplication (2.8 X 10(-7) M) or simultaneous application in high concentration (1.4 X 10(-5) M). 5. On the basis of these observations, it was postulated that Ca2+ concentration-dependent changes of the responses to 60 mM K+ and 0.6 M Na+ results from Ca2+-dependent "membrane surface potential" changes. The suppressed response to BK by Ca2+ depletion may be explained by the intervention of Ca2+-dependent processes other than PG production.

Animals↗
PubMed1989

Alkaline phosphatase expression in human cell lines derived from primary hepatomas.

Isozyme patterns of alkaline phosphatase (ALP) were electrophoretically examined in human cell lines derived from one hepatoblastoma, five hepatocellular carcinomas (HCCs) and two cholangiocellular carcinomas. Most of the cell lines tested had a liver-type ALP isozyme. In addition, an abnormal ALP isozyme, which was similar to variant ALP, was detected in one hepatoblastoma and two HCC cell lines. One HCC cell line of these variant-like ALP-positive cell lines was alpha-fetoprotein (AFP)-negative. These findings suggest that variant-like ALP may be useful for the identification of human hepatoma cell lines, especially in AFP or albumin-negative cell lines.

Alkaline Phosphatase↗
PubMed1989

Androgen-induced production of colony-stimulating factor (CSF) and colony-inhibitory factor (CIF) in the submandibular gland in female mice.

Both testosterone (T) and 5 alpha-dihydrotestosterone (DHT) significantly increased colony-stimulating factor (CSF) as well as colony-inhibitory factor (CIF) in the submandibular gland (SMG) in female mice. The CIF activity was completely inactivated by heating at 60 degrees C for 15 min, while the CSF activity was stable against the heat treatment. It was found that the CSFs obtained from the androgen-treated female mice and from normal male mice behaved identically in chromatography on hydroxylapatite and Ultro-gel AcA 34 columns. The potency of DHT to increase CSF activity was about 10 times greater than that of T.

Androgens↗
PubMed1989

Glucagon synthesis with mRNA preparation of a glucagon-producing tumor (IT-1).

Nucleic acids were extracted from the tumor (IT-1) and purified to give poly (A)-containing RNA, which was subjected to protein synthesis in vitro with a wheat germ extract. Gel-filtration (Bio Gel P-30) profiles of the translated product showed the presence of glucagon-like substance, and the results of treatment of fractions with glucagon antibodies (30K or K4023) showed the possibility that translated products contained true-glucagon. This confirms glucagon synthesis in IT-1. The molecular weight of the translated glucagon was estimated to be 3,000 from the K-value. The time courses of the glucagon synthesis were examined in cultured tumor cells (ITC-1) using 3H-leucine as a tracer. A large molecular weight protein was already detected after pulse labeling for 1 h. The amount of labeled glucagon in the cells was shown to be maximum at 1 h. True-glucagon was converted at 3 h to smaller molecular weight peptides which reacted with the C-terminal antibody of glucagon. In vitro protein synthesis, peptides with molecular weights of around 10,000 were major products in 15-30 min.

Adenoma, Islet Cell↗
PubMed1989

Examination of HeLa cell contamination of human cell lines derived from primary hepatomas using glucose-6-phosphate dehydrogenase and lactate dehydrogenase isozymes.

Isozyme patterns of glucose-6-phosphate dehydrogenase (G6PD) and lactate dehydrogenase (LDH) in human cell lines derived from primary hepatomas were compared with those in HeLa cells. Some cell lines derived from primary hepatomas having type B G6PD showed one or two isozymes of LDH. On the other hand, HeLa cells having type A G6PD showed four LDH isozymes. These findings suggest that not only G6PD, but also LDH may be useful for the detection of HeLa cell contamination of a culture in some cases.

Carcinoma, Hepatocellular↗
PubMed1989

Effect of various factors and substrates on the growth of a human hepatoblastoma cell line, HuH-6 in a serum-free medium.

The effect of various factors and substrates on the growth of a human hepatoblastoma cell line, HuH-6, which was inoculated at low density in a serum-free medium was examined. Several supplements were required to enhance cell growth of HuH-6. These included cholera toxin (CT), glucagon (Glu) and selenium (Se). Type IV collagen (C-IV) provided the most conductive environment tested for cell growth. These results suggest that CT, Glu, Se, and C-IV are important stimulators for the continuous growth of HuH-6 in a serum-free medium at low density.

Animals↗
PubMed1989

[Background of low-level gamma-ray spectrometer due to the atmospheric 220Rn and 222Rn].

In connection with low-level gamma-ray counting of natural samples, background due to 220Rn- and 222Rn-daughters was monitored. The results obtained for 4 months showed that the background gamma-ray from 222Rn-daughters was more variable than that of 220Rn-daughters. An efficient air-conditioning was helpful to keep the background stable. It was practically equivalent to the use of N2-gas. Radiometric data for dust samples filtered from the laboratory air suggested that Rn-daughters tended to be removed by air-conditioning.

Air Pollutants↗
PubMed1989

[Studies on AFP-producing capacity and some other properties of human hepatoma cells treated with various anticancer drugs].

The effect of various anticancer drugs on alpha-fetoprotein (AFP) secretion and some other properties of human hepatoma cells was investigated in vitro with the following results. (1) There was a high correlation between AFP secretion and cell number after treatment of human hepatoma cells with anticancer drugs and the amounts of AFP secreted per 10(4) cells per 72 hours (AFP-secreting capacity) were not affected within therapeutically achievable concentrations (TAC). (2) The AFP-secreting capacity was affected with some exceptions in the cells treated with higher concentration of drugs than TAC. Furthermore, chromosomal and morphological aberrations in the similarly treated cells, were also observed, suggesting the relationship between the change of AFP-producing capacity and that of some other properties.

Antineoplastic Agents↗
PubMed1989

[A study of MTT-hybrid assay using human bone and soft tissue tumor cells].

We investigated a new chemosensitivity test, MTT-hybrid assay, which was a hybrid of MTT colorimetric assay and double-layered soft agar colony assay, using human bone and soft tissue tumor cells. MTT formazan crystals produced by viable cells in the soft agar medium were solubilized by SDS at 60 degrees C. The absorbance (560 nm) is directly proportional to the cell number over a wide range. The absorbance increased in proportion to colonial growth of osteosarcoma cells, while it decreased in a human diploid cell strain in a few days. Drug sensitivity of tumor cells is supposed to be assessed without contaminating normal cells by MTT-hybrid assay in primary tumor samples. Good correlation of IC50 was observed between MTT-hybrid assay and colony assay. The MTT-hybrid assay shows potential value as a rapid predictive test for chemotherapeutic agents in an individual patient.

Antineoplastic Agents↗
PubMed1988

Alteration of insulin and glucagon secretion from the perfused BB rat pancreas before and after the onset of diabetes.

Secretion of insulin and glucagon from perfused BB rat pancreas was examined in rats (5 weeks old; n = 6) before and 2 weeks after (13 weeks old; n = 5) the onset of diabetes mellitus. The secretion of insulin and glucagon was modified by increasing concentrations of glucose in the perfusate from 2.8 mM to 16.5 mM. In 5-week-old BB rats, glucagon secretion was higher at the low glucose concentration (2.8 mM) and insulin secretion lower at the high glucose concentration (16.5 mM) than the corresponding values in age-matched control rats. In 13-week-old BB rats, insulin secretion was undetectable irrespective of glucose concentration. Glucagon secretion was only moderately suppressed by the perfusion of high glucose (16.5 mM) and was significantly higher than that of age-matched controls. The reduction in insulin secretion observed in 5-week-old rats without insulitis indicated that pancreatic B cells of BB rats of this age are somehow injured by humoral factors rather than cell infiltration. Cell function was apparently modified indirectly by the destruction of neighboring B cells.

Aging↗
PubMed1988

Establishment and characterization of a cell line from a human cholangiocellular carcinoma.

A cell line, HuH-28, was established in vitro from a patient with cholangiocellular carcinoma (CCC). This cell line has grown slowly, revealing a doubling time of approximately 80 h, and the serial passages were carried out 20 times within 10 months. Light microscopy revealed spindle and polygonal morphology of the cells. Chromosome number of the cells were distributed near the hypotriploid region at passages 3 and 14. HuH-28 cells were not transplantable into nude mice, but secreted some tumor markers including alkaline phosphatase (ALP), gamma glutamyltranspeptidase (GGT), beta 2-microglobulin (BMG), ferritin, elastase-1, and tissue polypeptide antigen (TPA). This HuH-28 cell line will represent a good model for the investigation of carcinogenesis, histogenes, and diagnosis of CCC.

Adenoma, Bile Duct↗
PubMed1988

Isolation of clones from T24 cells and test of their sensitivity to adriamycin.

Two single cell clones, CL3 and CL7, were developed from T24 cells. CL3 had abundant cytoplasmic granules, while CL7 did not have as much. CL3 and CL7 exhibited a modal number of chromosomes at 69 and 74, respectively. CL7 had a higher growth rate than CL3, as indicated by in vitro cell growth, plating efficiency, and growth of the tumors produced in nude mice. CL3 was slightly susceptible to adriamycin toxicity as compared to CL7.

Animals↗