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Biomedical subjects

K Sato

Publications and source records attributed to K Sato.

At least 19 recordsLinked to original sources
PubMed1979

Study of an asymmetric ESR signal in x-irradiated human tooth enamel.

An asymmetric ESR signal and an outer doublet signal centered at g = 2.00 produced in human tooth enamel by X-irradiation have been studied over a temperature range from liquid helium temperature to 380 degrees K. The line shape of the asymmetric signal for an enamel crystallite is Lorentzian at room temperature. The temperature dependence of the integrated intensity of the asymmetric signal suggests that the signal follows a singlet-triplet model with the exchange interaction of 0.022 eV. Below about 60 degrees K the asymmetric signal becomes broad as the temperature is decreased. The ENDOR line of the asymmetric signal shows that there exists interaction between the centers and protons. The temperature dependence of the integrated intensity of the double signal is analogous to that of the asymmetric signal.

Absorption↗
PubMed1979

[The vasopressor role of ADH in the maintenance of blood pressure in experimentally hypertensive rats (author's transl)].

In order to investigate the vasopressor role of ADH in the regulation of blood pressure, passive immunization experiments with an antibody to AVP were carried out in experimentally hypertensive rats. In hypertensive rats treated with deoxycorticosterone acetate (DOCA), spontaneously hypertensive rats (SHR) and spontaneously hypertensive stroke-prone rats (SHR-sp), the intravenous injection of a specific vasopressin antibody resulted in a transient fall of blood pressure of 11 approximately 25mmHg, while in rats with two-kidney Goldblatt hypertension and normal rats, the blood pressure was not affected. This strongly suggests that ADH contributed to systemic vaso-constriction in DOCA hypertension and spontaneous hypertension in rats.

Animals↗
PubMed1979

The high autoantibody activity of antibodies to rat skeletal muscle glycogen phosphorylase b produced in rabbits.

Antibodies to rat skeletal muscle glycogen phosphorylase b were prepared in six rabbits by weekly injection of the enzyme emulsified with complete Freund's adjuvant. All the antiserum preparations showed high autoantibody activities to react with the rabbit muscle enzyme in both inhibition of enzyme activity and precipitation. In Ouchterlony double diffusion in agar, the antiserum preparations were precipitable to give a distinct spur between the two precipitin lines formed with rat and rabbit enzymes. When the autoantibody index was taken as per cent cross-reactivity of rabbit enzyme with rat enzyme, the autoantibody indices of inhibition and precipitation of one of the antiserum preparations were as high as 98% and 52.3%, respectively.

Animals↗
PubMed1979

Studies on antiviral glycosides. II. Mode of action for virucidal effects on Sendai virus.

Treatment of Sendai virus with p-(sec-butyl)-phenyl-6-chloro-6-deoxy-beta-D-glucopyranoside, followed by freezing and thawing resulted in a loss of hemolytic and cell fusion activities as well as infectivity without affecting hemagglutinating and neuraminidase activities. The anti-hemolytic activity of this compound was reversed by the addition of phosphatidyl choline to the virus samples. p-Azidophenyl-6-chloro-6-deoxy-beta-D[3H]glucopyranoside was successfully used for photoaffinity labeling of a specific virion site, and we confirmed the affected site of the glucoside to be the lipid components in the viral envelopes.

Antiviral Agents↗
PubMed1979

Mutual homology of mouse immunoglobulin gamma-chain gene sequences.

We have assessed the relative homology of mouse immunoglobulin heavy-chain gene sequence using complementary DNAs (cDNAs) synthesized against gamma-chain mRNAs (gamma 1, gamma 2a, gamma 2b, and gamma 3) purified from mouse myelomas. cDNAs complementary to the gamma-chain mRNAs did not cross-hybridize with the mu- and alpha-chain mRNAs, whereas they cross-hybridized to significant extents (22--66%) with the gamma-chain mRNAs of other subclasses. The heterologous hybrids formed, however, melt at 5--13 degrees C lower temperatures as compared to the homologous hybrids, indicating that significant portions of the heterologous hybrids are mismatched. The rates of the cross-hybridization reactions are 2- to 17-fold slower than those of the homologous hybridization reactions. Therefore, the gamma-chain gene sequences of four subclasses share a part of homology with each other, but they are different enough to be measured separately. Cross-hybridization analysis indicate that the gamma 2a and gamma 2b genes are the most closely related, while the gamma 1 and gamma 3 genes are the least related among the gamma subclass genes.

Animals↗
PubMed1979

Polyspermy-preventing mechanisms in mouse eggs fertilized in vitro.

The time sequence of the mechanisms that prevent polyspermy in cumulus-free mouse eggs was determined by continuous micropscopic observations during in vitro fertilization. The zona reaction had begun, and the vitelline surface block to polyspermy was established, in less than one minute following sperm fusion with the vitellus. In less than five minutes, the zona reaction had advanced to the stage that no more spermatozoa could become firmly attached to the surface of the zona pellucida.

Animals↗
PubMed1979

Isolation of UV-sensitive variants of human FL cells by a viral suicide method.

A new method (viral suicide method) for the isolation of UV-sensitive mutants is described. Colonies of mutagenized human FL cells were infected with UV-irradiated Herpes simplex viruses and surviving ones which seemed to be deficient in host cell reactivation (HCR) were examined for their UV sensitivity. Nineteen of 238 clones examined were sensitive to UV irradiation at the time of the isolation. After recloning, four of these clones have been studied and two (UVS-1 and UVS-2) of them are stable in their UV sensitivity for 4 months in culture. UV sensitivity of UVS-1, UVS-2, and the parental FL cells are as follows: the extrapolation numbers (n) are 2.2, 2.1, and 1.8 and mean lethal doses (D0) are 2.9, 3.7, and 7.8 J/m2 for UVS-1, UVS-2, and the parental FL cells, respectively- They are no more sensitive than FL cells to X-irradiation. The ability of HCR in UVS-2 cells is apparently lower than that in FL cells, whereas UVS-1 cells are the same as FL cells in the ability.

Amnion↗
PubMed1979

Application of magnification radiography to the biliary system.

Magnification radiography was applied for the diagnosis of the biliary tract diseases including cancer. Our X-ray unit was consisting of HITACHI DR-155-23 U-6M-55P and 0.1 mm focal-spot tube, FFD 80 cm giving a magnification of x2 with the conditions of 60 kVp, 20 mA, 0.8 sec. Intensifying screens such as Kyokko LH II (for a standard sized subject) or DuPont Q II (for an obese subject) were used in combination with Fuji RX films. We confirmed a high diagnostic value in revealing early lesions of this sytem. The skin dose test indicated that this technique was routinely applicable with safety for clinical use.

Biliary Tract↗
PubMed1979

Studies on antiviral glycosides, 4. Inhibition of the multiplication of paramyxoviruses by phenyl-6-chloro-6-deoxy-beta-D-glucopyranoside.

The antiviral activity of phenyl-6-chloro-6-deoxy-beta-D-glucopyranoside (PCG) was studied. PCG specifically inhibited the growth of paramyxoviruses including Sendai, measles and Newcastle disease viruses in LLCMK2 cells at a concentration of 0.5 to 1.0 mM, but did not restrict the multiplication of other RNA viruses (influenza, vesicular stomatitis and polio viruses) at these concentrations. PCG might act in the late stage during virus replication of Sendai virus as it did not inhibit virus RNA and protein synthesis in the infected cells. Comparative studies on the biological properties of virus particles grown in the presence and absence of PCG demonstrated that treatment with it caused the formation of non-haemagglutinating particles.

Antiviral Agents↗
PubMed1979

Benign duodenocolic fistula due to duodenal diverticulum: report of two cases.

Two cases of benign duodenocolic fistula resulting from duodenal diverticula are presented. In both cases, the diverticula were located on the outer border of the second portion of the duodenum. The upper gastrointestinal study is the easiest and most useful examination for diagnosis. Hypotonic duodenography and the barium enema complement the upper series and serve to differentiate benign from malignant fistulas.

Aged↗
PubMed1979

Angiographic assessment of lymphatic metastasis from gastric cancer.

Lymph node metastasis was evaluated angiographically in 151 patients with gastric cancer. In 20% of the patients with nodal metastases, abnormally staining masses were demonstrated by angiography. Superselective angiography is useful in confirming the presence of lymph node involvement.

Aged↗
PubMed1979

Mechanical properties and functions of the myoepithelium in the eccrine sweat gland.

Contractile properties of an isolated segment of the secretory coil of the monkey palm eccrine sweat gland were studied in vitro with a transducer. Contraction of up to 10 mgf was induced with acetylcholine but not with alpha or beta adrenergic agonists, caffeine, prostaglandin E1, or by a calcium ionophore A23187. Other features included K+ contracture, staircase effect, poor extensibility, length-tension relationship with a peak tensile response at 115--120% of the resting length, and requirement of Ca2+. The function of myoepithelium is unlikely to expulse the preformed sweat because the amount of preformed sweat is small, K+-contracture failed to expulse sweat, and because myoepithelial contraction was not induced by such stimulants of sweat secretion as A23187, phenylephrine, isoproterenol, and prostaglandin E1. The maximal transverse tension of 20 mgf during acetylcholine stimulation under resting tension was calculated to support the luminal hydrostatic pressure of approximately 500 mmHg. Thus the function of the myoepithelium may be to render structural support for the secretory epithelium.

Acetylcholine↗
PubMed1979

Rat hyperplastic hepatic nodules and primary hepatomas retaining abnormally high pyruvate kinase L type activity.

As reported in our previous paper (Sato et al., Cancer Res., 38: 3086-3093, 1978), most of the hyperplastic hepatic nodules and primary hepatomas induced by N-2-fluorenylacetamide (2-FAA), diethylnitrosamine (DENA), and 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) showed that pyruvate kinase liver (L) type decreases and the prototypic M2 type increases concomitantly with dedifferentiation of tissues. However, at least 14 samples among 120, mostly hyperplastic nodules and highly differentiated hepatomas induced by 2-FAA or DENA, retained exceptionally high activities of the L type, while other enzymes of carbohydrate metabolism in these tissues deviated toward a common pattern similar to that in the fetal liver. Individual patterns of 9 enzymes including pyruvate kinase of carbohydrate metabolism in these samples are arranged and discussed as examples of unbalanced enzyme deviation in hepatocarcinogenesis.

Animals↗