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Biomedical subjects

M Asano

Publications and source records attributed to M Asano.

At least 559 records · Page 31Linked to original sources
PubMed1980

Distribution of likelihood ratio in relation to the exclusion probability.

The relation between the exclusion probability (E) and the paternity probability is derived by assuming the distributions of logarithm of paternity likelihood ratio, log(Y/X) for true fathers and unexcluded non-fathers as the normal distributions. Under this assumption the value log(1-E) is equal to the mean of the mean value for true fathers (a) and that for unexcluded non-fathers (b), i.e., log(1-E)=(a+b)/2. This relation holds quite well for the various actual distributions of log(Y/X) of father-child combinations and those of father-mother-child combinations using 14 blood group systems. Therefore, the derived relation is found to be a convenient way to deduce one of the three quantities (E, a, b) from the remaining two quantities in the actual distributions.

Blood Group Antigens↗
PubMed1980

A new approach to the computation of indices of paternity.

This paper describes an algorithm to calculate several indices of paternity (combination frequency, paternity likelihood (Y/X) and paternity exclusion probability (E) for father-mother-child combination (trio) as well as father-child combination (duo). This program is written in FORTRAN IV and applicable to any kinds of blood group systems such as Rh and HLA. The characteristic points of the present method are as follows: First, the relation between genotypes and phenotypes is given in a straightforward way by introducing a translational matrix. Secondly, by a unit run on a computer, several indices of paternity are tabulated for all kinds of combinations of trio as well as duo. Finally, the efficiency of diagnosis of a certain system is listed by calculating the distribution of log (Y/X).

Child↗
PubMed1980

Potentiation of the contractile response to acetylcholine in aortic strips by low concentrations of vascular contractile agonists.

1 The potentiating effect of a low concentration of various vascular contractile agonists on the response of rabbit aortic strips to acetylcholine was examined. 2 A marked parallel displacement to the left (potentiation; not additive effect) of the dose-response curve for acetylcholine was observed when 5-hydroxytryptamine (5-HT), noradrenaline, histamine, angiotensin II or KCl were added at a concentration that caused only slight contraction (0.2 to 0.3 g) in the strips. This leftward displacement (potentiation) of the dose-response curve by these agonists was reversed to the control response curve by the respective blocking agents for each agonist, although the blocking agents themselves did not shift the acetylcholine dose-response curve to the right. Atropine produced a rightward displacement of the dose-response curve for acetylcholine. 3 The addition of an extremely low concentration of 5-HT or KCl which did not cause contraction, also produced a potentiation. 4 The order of potency of the agonists in potentiating the acetylcholine-induced contraction was KCl > 5-HT greater than or equal to histamine greater than or equal to angiotensin II > noradrenaline. 5 The contractile response of aortic strips to carbamylcholine was also potentiated by these agonists. 6 The results suggest that the potentiation by these agonists was not mediated through muscarinic receptors but through the respective receptors for each agonist.

Acetylcholine↗
PubMed1980

Cutaneous microcirculatory effects of various vasodilator agents on the conscious rabbit, with special regard to changes in the rhythmic property of vasomotion.

Microcirculatory effects of intravenous administrations in the appropriate doses of phenoxybenzamine (POBA), phentolamine (PTA), nicotinic acid (NAc), trimetazidine (TMZ), dilazep (DZ), cepharanthine (CT), alpha-tocopheryl acetate (TP-A), and alpha-tocopheryl nicotinate (TP-N) as vasodilator agents were investigated in the subcutaneous tissue within a transparent ear chamber of the normal conscious rabbit. The intra-vital microscopic findings obtained following administration of the drugs were as follows: POBA, a marked and long-lasting vasodilatation without vasomotion (more than 1 hour); PTA, a quite brief vasodilatation followed by a marked and long-lasting vasoconstriction without vasomotion (more than 1 hour); NAc, a short-lasting vasodilatation with slightly blunted vasomotion (less than 10 minutes); TMZ, DZ, CT, TP-A, and TP-N, a similar notable and transient vasodilatation with vasomotion (about 1 hour or more). Some physiological implications on the microcirculatory changes induced by administrations of the drugs were discussed especially in relation to the significance of sustaining the rhythmic fluctuations of blood flow due to vasomotion.

Animals↗
PubMed1979

Calculation of likelihood ratio y/x in diagnosis of paternity using computer methods.

A new computational method using a Monte Carlo technique is described for the calculation of plausibility of paternity in blood group systems. In this study gene frequencies of a blood group system are simulated by the range of the seven digit random numbers. By using a Monte Carlo method, four random numbers are generated and converted into paternal and maternal genotypes. Then the genotype of the child is determined according to the law of inheritance, and finally genotypes of the father, mother and child are converted into phenotypes. Repeating this process more than one hundred thousand times, the phenotypic frequencies of child-mother-father combinations (trio) and the likelihood ratio of paternity in any blood group system are calculated for all phenotypic combinations of the trios. This method is much easier than methods reported previously, and is sufficiently accurate.

Blood Group Antigens↗
PubMed1979

Multiplicity of monoamine oxidase in chick brain.

The substrate- and inhibitor-related characteristics of monoamine oxidase (MAO) were studied on chick brain mitochondria. It was found that neither 5-hydroxytryptamine nor beta-phenylethylamine is the specific substrate for type A and type B MAO in chick brain.

Animals↗
PubMed1979

Malignant breast tumors among atomic bomb survivors, Hiroshima and Nagasaki, 1950-74.

For 1950-74, 360 cases of malignant breast tumors were identified among the 63,000 females of the Radiation Effects Research Foundation's (Hiroshima and Nagasaki) Extended Life-Span Study sample of survivors of the 1945 atomic bombings of Hiroshima and Nagasaki; 288 of these females were residing in one of these two cities at the time of bombing (ATB). Two-thirds of all cases were classified as breast cancers on the basis of microscopic review of slides, and 108 cases received an estimated breast tissue dose of at least 10 rads. The number of cases of radiogenic breast cancer could be well estimated by a linear function of radiation dose for tissue doses below 200 rads. Excess risk estimates, based on this function, for women 10-19, 20-29, 30-39, and 50 years old or older ATB were 7.3, 4.2, 2.6, and 4.7 cases per million women per year per rad, respectively. Women irradiated in their forties showed no dose effect. Among all women who received at least 10 rads, those irradiated before age 20 years will have experienced the highest rates of breast cancer throughout their lifetimes. Separate excess risk estimates for Hiroshima and Nagasaki did not differ significantly, which indicates that for radiogenic breast cancer the effects of neutrons (emitted only in the Hiroshima explosion) and gamma radiation were about equal. Radiation did not reduce the latency period for the development of breast cancer, which was at least 10 years. The distribution of histologic types of cancers did not vary significantly with radiation dose. The data suggested that irradiation prior to menarche conferred a greater risk than irradiation after menarche.

Adolescent↗
PubMed1978

Mechanism of the formation of megamitochondria by copper-chelating agents. IV. Role of fusion phenomenon in the cuprizone-induced megamitochondrial formation.

Megamitochondria were induced within 36-40 hours in mouse hepatocytes by injecting cuprizone into the peritoneal cavity. Induction of megamitochondria was dependent upon the amount and the time intervals of the injection of cuprizone: 200 mg of cuprizone/kg of body weight-injected every 12 hours or 400 mg of cuprizone/kg of body weight-injected every 24 hours. When the latter amount of the noxious reagent was administered to the animal every 12 hours, fatty changes of the liver was observed. Involvement of the fusion phenomenon in the mechanism of megamitochondrial formation is discussed in the light of turnover rates for various components of the mitochondrion.

Animals↗
PubMed1978

Mechanism of the formation of megamitochondria by copper-chelating agents. V. Further studies on isolated megamitochondria.

Effect of cuprizone has been studied on some biochemical properties of megamitochondria obtained from the mouse liver. (1) Contents of Ca2+, Mg2+ and Cu2+ in the blood or the liver homogenates were not altered by cuprizone intoxication, whereas those in liver mitochondria were significantly altered: after 3-4 days' intoxication, content of Ca2+ was decreased and was remarkably increased after 14-15 days' intoxication. Content of Mg2+ behaved contrarily. (2) Both cytochrome oxidase and ATPase activities were unchanged in the liver megamitochondria, but monoamine oxidase (MAO) activity was significantly decreased. Value of I50 (50% inhibition) for MAO was determined to be 0.33 mM using the control liver mitochondria. Cuprizone had almost no effect on MAO activity of kidney or heart mitochondria both in vivo and in vitro. (3) The amount of lysolecithin was increased in the liver megamitochondria. These results were discussed in the light of membrane fusion phenomenon which plays a key role in the mechanism of megamitochondrial formation.

Adenosine Triphosphatases↗
PubMed1978

Multiple forms of monoamine oxidase in developing chick brain.

The developmental change in the multiplicity of monoamine oxidase (MAO) forms of chick brain was studied with regard to substrate specificity and inhibitor sensitivity. The developmental pattern of MAO activity towards beta-phenylethylamine was generally similar to that of MAO activity towards 5-hydroxytryptamine. The inhibition study showed that the ratio of type A MAO to type B MAO in chick brain increased during development. This is quite different from results obtained in mice, rats, guinea pigs, and humans, and is not consistent with the idea that in immature brain type A MAO predominates.

Animals↗
PubMed1978

Involvement of calcium in cyclic nucleotide metabolism in human vascular smooth muscle.

When cyclic nucleotide phosphodiesterase was purified from isolated smooth muscle layer of human aorta by DEAE-cellulose column chromatography, separated cyclic GMP phosphodiesterase activity was markedly stimulated in the presence of 10-20 micrometer of Ca2+ by a protein modulator which has similar physicochemical properties to troponin C. Synthetic compound, N-(6-aminohexl)-5-chloro-1-naphthalensulfonamide, which produced relaxations of arteries contracted by prostaglandin F2alpha or KCl was found to inhibit selectively this Ca2+-dependent cyclic GMP phosphodiesterase. This compound produced inhibition of superprecipitation of myosin B system obtained from mouse skeletal muscle and also inhibited adenosine triphosphatase activity of myosin B. Our data suggest that calcium is involved through a protein modulator in cyclic nucleotide metabolism of vascular smooth muscle and that the calcium-dependent protein modulator probably participates in the regulation of contractile response of vascular smooth muscle by affecting actomyosin ATPase activity.

3',5'-Cyclic-GMP Phosphodiesterases↗