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Biomedical subjects

M Umeda

Publications and source records attributed to M Umeda.

At least 451 records · Page 25Linked to original sources
PubMed1983

HVJ-mediated fusion between erythrocyte membranes and liposomes containing glycophorin.

The HVJ-mediated interaction of liposomes containing glycophorin with human erythrocytes was studied. A ternary complex of erythrocyte-HVJ-liposome was formed on incubation at 4 degrees C. Spin-labeled phosphatidylcholine and spin-labeled galactosylceramide, both of which were incorporated into liposomes, were effectively transferred into erythrocytes upon shifting-up of the incubation temperature to 37 degrees C. This finding indicates that fusion between glycophorin liposomes and erythrocytes occurs in the presence of HVJ. Fusion could be also inferred from the transfer of radio-labeled lipids embedded in the liposomal membranes to erythrocyte membranes as well as uptake of solutes entrapped in the aqueous space of the liposomes by erythrocytes. The total amount of liposomes fused with erythrocytes depended on the glycophorin content of liposomes and the amount of HVJ added. No transfer was observed when trypsinized HVJ was used in place of HVJ, suggesting that the fusion is F protein dependent.

Animals↗
PubMed1983

Cultivation of V79 cells in serum-free medium containing bovine serum albumin and the use of gelatin as an attachment factor.

V79 cells were cultivated in a serum-free medium. When a serum-free, bovine serum albumin-containing medium was used, removal of trypsin after cell detachment during subcultivation was necessary for routine mass cultivation. For colony formation addition of an attachment factor to the medium was further necessary. Gelatin was proved to serve as a good attachment factor in the colony formation and it could be substituted for fibronectin as an attachment factor for serum-free cultivation of many types of cells.

Animals↗
PubMed1983

[Effect of cefotaxime in the treatment of infections associated with hematologic diseases].

Twenty patients suffering from severe infections (9 with respiratory tract infection, 9 with urinary tract infection, 2 with pharyngitis, 1 with enteritis and 4 with fever of unknown origin (FUO] were treated by intravenous infusing CTX 2 g over 30 to 40 minutes 2 or 3 times daily for 4 to 10 days. Other antibiotics were concomitantly used in 9 cases. Response to CTX was proved good in 15 cases (75%), fair in 3 cases and poor in 2 cases. No adverse reactions were observed.

Adolescent↗
PubMed1983

Effect of insulin on the transformation of BALB/3T3 cells by X-ray irradiation.

The effects of triiodothyronine (T3), hydrocortisone, and insulin on X-ray-induced transformation of BALB/3T3 A31-1-1 cloned cells were examined. Under the experimental conditions employed, the addition of 10(-7) M T3 or hydrocortisone to the serum-containing medium had little effect on the transformation. In contrast, the addition of insulin dramatically enhanced the transformation. The effect of insulin was concentration-dependent up to 10 micrograms/ml and was consistently observed with X-rays at various doses.

Animals↗
PubMed1983

[31P-NMR analysis of high energy phosphorous compounds (ATP and phosphocreatine) in the living rat brain--effects of halothane anesthesia and a hypoxic condition].

31phosphorus nuclear magnetic resonance (31P-NMR) measurements have provided new and valuable insights for studying the metabolism of living systems. The aim of this paper is to introduce a technique of application of 31P-NMR measurements using a surface coil method, and to discuss the effects of halothane anesthesia and hypoxic hypoxia on the energetic metabolism of intact rat brains. All measurements were made using a JEOL FX 270 spectrometer with a super conducting magnet of 54-mm bore diameter. The magnetic field intensity of this machine is 6.3 tesla, and the resonance frequency used for 31P was 109.14 MHz. We remodelled an ordinary probe to take a live rat, and the animals were made to inhale anesthetic halothane or mixture of oxygen and nitrogen at various concentrations controlled by a flow regulator. The best conditions for measurements with our surface coil method were determined in this study as follows: (1) 90 degrees pulse width and selectivity, Fig. 1 shows signal selectivity in depthwise direction changed with 90 degrees pulse width, which was set to 20 microseconds. (2) Sensitivity and resolution; To obtain a spectrum of 31P-NMR from a rat brain 500 accumulations of free induction decays were considered suitable for both time and space resolution. Fig. 2 shows variations of signal intensity with pulse repetition time, which was set to 2 sec. It took about 17 min for averaging to get a spectrogram. (3) Quantitative accuracy and qualification; As shown in Fig. 3, a linear relationship was found between the signal intensity of beta-phosphate of ATP and the concentration of ATP solutions, thus proving the quantitative accuracy of our systems.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1983

Concentration-dependent differential effect of retinoic acid on intercellular metabolic cooperation.

A vitamin A analog, 13-cis-retinoic acid (13-cis-RA), was tested for effect on intercellular metabolic cooperation between 6-thioguanine-resistant and -sensitive V79 Chinese hamster cells. Most typical tumor promoters have been reported to inhibit metabolic cooperation. 13-cis-RA was found to enhance metabolic cooperation of cells treated with a potent tumor promoter, 12-O-tetradecanoyl-phorbol-13-acetate. However, inhibition of metabolic cooperation was noticed when 13-cis-RA was used at higher concentrations.

Animals↗
PubMed1983

Difference in polynucleation of cultured cells from human mammary tumors and normal mammary glands on treatment with cytochalasin B.

In order to study the biological nature of various mammary tumors, differences in the formation of polynuclear cells after the administration of cytochalasin B were investigated in cultures of human mammary tumors and normal mammary gland. When cytochalasin B was applied to the cultures, polynuclear cells increased in all cancer cases (6.1% on average), but relatively little effect was seen in cases of benign tumors and normal mammary gland (less than 1.1% on average). From these results, it appears that the difference in polynucleation on treatment with cytochalasin B may be useful as a biological means to distinguish human malignant and benign mammary tumors.

Breast↗
PubMed1982

[On susceptibility for carbon monoxide exposure. The effect of carbon monoxide exposure on hepatic drug metabolizing enzymes of mice].

Male mice were exposed to three levels of carbon monoxide, i.e. 500, 1,000 and 3,000 ppm for 60, 10 and 7 minutes per day respectively. Durations of the exposure were 1 and 5 days and 3, 6 and 9 weeks. As the effect of carbon monoxide exposure, induction of the drug metabolizing enzyme was observed, which was ascertained by the decrease of sleeping time by pentobarbital and by the increase of activities of liver microsomal p-nitroanisole demethylase and of aniline hydroxylase. These results should be due to an adaptive response to carbon monoxide exposure, but the mechanisms of the enzyme induction were not fully explained in this study. In 5 days' exposure to carbon monoxide, there was a dose-response relationship between the degree of carbon monoxide exposure and the extent of enzyme induction. But in the prolonged exposure to higher concentrations of carbon monoxide (1,000 and 3,000 ppm), the increase of drug metabolism became less pronounced and by 9 weeks' exposure to 1,000 ppm carbon monoxide, little induction of the drug metabolizing enzyme was observed. These results suggest that the induction of the drug metabolizing enzyme by carbon monoxide exposure has a certain limit.

Aniline Hydroxylase↗
PubMed1982

Short-term cultivation of human mammary tumors and normal mammary glands in medium containing human colostrum milk.

A short-term cultivation of human mammary tumors and normal mammary glands was attempted in order to establish a reproducible method for their cultivation. Epithelial cells could be cultivated consistently by the use of collagenase for tissue dissociation and the addition of insulin, human colostrum milk and cholera toxin to the culture medium. Human colostrum milk seemed to be a good additive for the growth of mammary epithelial cells but not for that of fibroblastic cells.

Breast↗
PubMed1982

Turbidimetric immunoassay of serum C-reactive protein.

This rapid, reliable equilibrium turbidimetric immunoassay for serum C-reactive protein involves a potent monospecific antibody. Polyethylene glycol-6000 to accelerate and enhance the immunoprecipitation reaction, and Tween-20 surfactant to lower and stabilize the sample blank values. Grossly lipemic, icteric, or hemolyzed sera can be assayed. Values up to about 220 mg/L, for which the standard curve is linear, can be measured without sample dilution. Results by the proposed method and by radial immunodiffusion (r 0.989) or laser nephelometry (r = 0.957) correlated well. Analytical recovery averaged 101.3%. Within-, between-, and day-to-day CVs ranged from 0.9% to 3.5%, 0.8% to 5.5%, and 1.9% to 4.8%, respectively. The method is demonstrably superior to radial immunodiffusion or nephelometry. Any spectrophotometer that can measure turbidimetrically at 340 nm can be used.

C-Reactive Protein↗
PubMed1982

Inhibition of metabolic cooperation in Chinese hamster cells by organochlorine pesticides.

Effects of organochlorine pesticides on the metabolic cooperation in the hypoxanthine-guanine-phosphoribosyl-transferase system using wild-type 6-thioguanine-sensitive V79 cells and variant 6-thioguanine-resistant cells were surveyed. The metabolic cooperation was inhibited by 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (TDE), 1,1,1-trichloro-2-(o-chlorophenyl)-2-(p-chlorophenyl)ethane (o,p'-DDT), 1,1,1-trichloro-2,2-bis(p-methoxyphenyl)ethane (methoxychlor), aldrin, dieldrin, endrin, heptachlor, alpha-isomer of benzene hexachloride (alpha-BHC), and gamma-BHC, but not beta-BHC. The present results suggest that the pesticides which inhibited the metabolic cooperation may be tumor promoters.

Animals↗
PubMed1981

Induction of chromosomal aberrations and 8-azaguanine-resistant mutations by aryldialkyltriazenes in cultured mammalian cells.

Inducibility of chromosomal aberrations, cell survival, and mutation to 8-azaguanine (8AG) resistance in cultured V79 cells by 1-phenyl-3,3-dimethyltriazene (PDMT), 1-phenyl-3,3-diethyltriazene (PDET), and 1-(pyridyl-3)-3,3-diethyltriazene (PyDET) were examined with or without metabolic activation. Chromosomal aberrations were induced in a dose-dependent manner by all 3 triazenes in a direct treatment for 24 h. Chromosomal aberrations were also induced by PDMT with metabolic activation system for 3 h, and little differences in the incidences were observed compared with those obtained by a direct treatment. All 3 triazenes were slightly mutagenic in a direct treatment for 24 h. In metabolic activation experiments, however, PDMT and PyDET were highly mutagenic. The mutagenicity, when compared with the cytotoxicity, was significantly higher in a metabolic activation system than in a direct treatment.

Animals↗