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Biomedical subjects

M Asano

Publications and source records attributed to M Asano.

At least 631 records · Page 35Linked to original sources

Effect of drug-vinyl copolymer delivery composites on the rat prostate.

A radiation polymerized drug-vinyl copolymer delivery composite (0.8 mm in diameter, 3 mm long) was inserted into the right-lobe ventral prostate (I), into the right testis (II), and subcutaneously (III) into the back of male Wistar rats. The implantation was carried out over a period of 12 weeks maximum. From the relationship between the site of surgical insertion of the implant and the physiologic response (as measured by the decrease in the weight of the prostatic organs, e.g., ventral prostates, dorsolateral prostates, and seminal vesicles), it was found that in an AA560-containing composite (36 micrograms daily), the physiologic response is increased in order of (III) greater than (II) greater than (I). The same tendency was observed in the Estracyt-containing composite system (15 micrograms daily). The difference in the physiologic response owing to the site of surgical insertion of the implant was not observed in an E2-17 beta-containing composite (6 micrograms daily), although this composite showed the strongest physiologic response. No physiologic response in rats with CMA-containing composite (28 micrograms daily) was noted.

Acrylates↗

Double-outlet technique for tetralogy of Fallot-type disease with an anomalous coronary artery.

To reduce the right ventricular (RV) pressure and the pressure gradient between the RV and the pulmonary artery (PA) in Tetralogy of Fallot (TOF) with small pulmonary annulus, it is inevitable to enlarge the small annulus by incising and patching from RV to PA via PA annulus. If the anomalous coronary artery exists in the RV outflow tract, the procedure can not be done.

Cardiac Surgical Procedures↗

A computer calculation of probability of monozygosity for twins.

A general algorithm is described to calculate the probability of monozygosity of concordant twins on the basis of blood type tests. Frequencies of all combinations of twins and parents are created with the aid of a translational matrix which facilitates conversion of genotypes to phenotypes automatically. The method of calculation is explained by taking Rh system in Germany as an example. The probability of monozygosity is calculated for all combinations of twin and/or father and/or mother. Effects of parental phenotypes on the efficiency in the diagnosis are analyzed quantitatively. Applicability of this method to other calculations concerning genetics is also discussed.

Blood Group Antigens↗

Zinc test as a new tool for identification of human seminal stains.

An extremely simple qualitative method for identification of seminal stains based on high levels of zinc in human semen is described. It uses reaction of 1-(2-pyridylazo)-2-naphthol with zinc to develop a deep red color. The data are presented on the sensitivity, stability and specificity of the present method. We can recommend it for identification of human semen especially in old or denatured samples.

Coloring Agents↗

Hepatic abscess secondary to a fishbone penetrating the gastric wall: CT demonstration.

Preoperative diagnosis of hepatic abscess due to foreign bodies penetrating the gastrointestinal tract is uncommon with conventional imaging methods. This report describes and illustrates a case of hepatic abscess secondary to a fishbone penetrating the gastric antrum wall which was diagnosed preoperatively by CT and confirmed at surgery. The value of CT in the preoperative diagnosis of cases of this kind is emphasized.

Female↗

Long-term effects of eicosapentaenoic acid on diabetic peripheral neuropathy and serum lipids in patients with type II diabetes mellitus.

The present study was undertaken to investigate the efficacy of a new, highly purified (purity greater than 91%), ethyl esterification product from natural eicosapentaenoic acid (EPA-E, C20:5 omega 3) in patients with type II diabetes mellitus (NIDDM). Hemodynamic changes were assessed at the level of the dorsalis pedis artery using an ultrasonic color Doppler duplex system before and after oral administration of EPA-E at a dose of 1800 mg/day for 48 weeks. The cross-sectional area of the dorsalis pedis artery increased significantly from 2.5 +/- 0.2 to 3.9 +/- 0.4 mm2 (48 weeks, mean +/- SE, p < 0.05). Moreover, EPA-E improved the clinical symptom (coldness, numbness) as well as the vibration perception threshold sense of the lower extremities [from 32.1 +/- 8.5 to 16.1 +/- 4.8 (48 weeks) microns]. A significant decrease of serum triglycerides was also noted by EPA-E administration. Furthermore, significant decrease of the excretion of albumin in urine [from 24.4 +/- 3.3 to 13.9 +/- 1.8 (48 weeks) mg/g.Cr, p < 0.05]. The results of this study suggest that EPA-E has significant beneficial effects on diabetic neuropathy and serum lipids as well as other diabetic complications such as nephropathy and macroangiopathy.

Adult↗

Use of a total right heart bypass model for analyses of abnormal hemodynamics in total artificial heart animals, and the function and regulatory mechanisms of a natural heart.

By fixing the function of one ventricle, a total right heart bypass model can clarify the function and regulatory mechanism of the natural heart, and the etiology of abnormal hemodynamics in TAH animals such as increased CVP blood pressure and hepatic congestion. The pulmonary artery of a right heart bypass in a goat was clamped proximally; the pulmonary circulation was thus supplied entirely by the artificial heart and the systemic circulation by the natural heart. This model enabled studies of long-term effects of an artificial right heart on systemic circulation at a right heart output of 80-100 ml/kg/min; the response of the natural left heart to changes in output of the right heart; and the response of the natural left heart and artificial right heart to treadmill exercise. It was found that only slight increase in CVP or no increase in blood pressure was observed during the experiment (112 days); a rapid increase in output of the RAH resulted in an increase in left atrial pressure, stroke volume and output of the left ventricle, and a decrease in its heart rate at rest; and significant increase in both artificial right heart and natural left heart output and heart rates were observed during treadmill exercise, despite the marked decrease in left atrial pressure. The above results suggest that the increase in CVP and blood pressure in total artificial heart animals are not due to factors involving the artificial right heart, and that although left ventricular function acts in accordance with Starling's law at rest, this is no longer true during treadmill exercise.

Animals↗

Quantitative changes of maximum contractile response to norepinephrine in mesenteric arteries from spontaneously hypertensive rats during the development of hypertension.

Maximum contractile responses of mesenteric arterial strips from spontaneously hypertensive rats (SHR) to norepinephrine (NE) were determined at all stages of hypertension (6-30 weeks of age), and data compared with findings in normotensive Wistar-Kyoto rats (WKY). Although the maximum responses to NE in the strips from both 6- and 14-week-old SHR--that is, before and after the development of elevated blood pressure--were significantly greater than those in the strips from age-matched WKY, the ratio of the maximum contraction induced by NE to that by KCl (NE/K+ ratio) was increased only after the development of hypertension. The difference in the NE/K+ ratio was also apparent in strips of femoral artery from 14-week-old rats but not in strips of thoracic aorta. The angiotensin II/K+ ratios in the three arterial strips, which were significantly decreased with advancing age of the rats, were not significantly different between the SHR and WKY. There was a good correlation between the NE/K+ ratios in the mesenteric arterial strips and the blood pressures of both SHR and WKY. It is concluded that the NE/K+ ratio in the mesenteric arterial strips was in good agreement with the onset of hypertension in SHR.

Aging↗

Effects of nicardipine, a dihydropyridine calcium antagonist, on regional myocardial blood flow, myocardial oxygen tension, and electrical abnormalities during acute coronary artery occlusion in dogs.

Effects of nicardipine, a dihydropyridine calcium antagonist, on regional myocardial blood flow (RMBF), myocardial oxygen tension (PO2), and excitation and conduction abnormalities during the occlusion of the left anterior descending coronary artery (LAD) were examined in anesthetized dogs, and compared with those of nifedipine and dipyridamole. RMBF was calculated from the H2 gas clearance curves, and PO2 was measured using a membrane-coated Pt wire. Excitation and conduction abnormalities during the LAD occlusion were represented in terms of the degree of ST-T alternans (STTA), TQ depression, and conduction delay, which appeared in epicardial electrograms. Nicardipine and nifedipine in a dose of 10 micrograms/kg increased RMBF and PO2 levels in nonischemic and mildly ischemic tissues, but not in severely ischemic tissues. Nicardipine in a dose of 100 micrograms/kg and nifedipine in a dose of 10 micrograms/kg attenuated the degree of STTA, TQ depression, and conduction delay observed in severely ischemic tissues. In mildly ischemic tissues where only TQ depression was observed without STTA, nicardipine in a dose of 30 micrograms/kg attenuated TQ depression. Dipyridamole in a dose of 1 mg/kg produced only a slight attenuation of STTA and conduction delay. These results suggest that the beneficial effects of nicardipine as well as of nifedipine on myocardial ischemia are due to the increase in the myocardial PO2 levels caused by the increased RMBF and also to direct protecting effects on ischemic myocardial cells. In the severely ischemic tissues, the latter is a main effect of the drugs. In increasing the PO2 level, nicardipine was similarly potent as nifedipine, but in the direct effect, nicardipine was less potent, and dipyridamole was almost ineffective.

Animals↗

Effects of a nonpeptide bradykinin B2 receptor antagonist, FR167344, on guinea-pig tracheal smooth muscle bradykinin receptors.

It is speculated that bradykinin may play an important role in asthma. Thus, bradykinin receptor antagonists may have therapeutic potential against asthma. Orally active bradykinin antagonists would be more desirable for the treatment of the disease. In the present study, we examined the effects of a novel, potent, selective, and orally active nonpeptide bradykinin B2 receptor antagonist, FR167344 (N-[N-[3-[(3-bromo-2-methylimidazo[1,2-a]pyridin-8-yl)oxymethyl]-2 ,4-dichlorophenyl]-N-methylaminocarbonylmethyl]-4-(dimethylamin ocarbonyl)cinnamylamide hydrochloride), on guinea-pig tracheal smooth muscle bradykinin receptors. FR167344 inhibited [3H]bradykinin binding to bradykinin receptors in epithelium-denuded guinea-pig tracheal membrane with an IC50 of 2.1 nM and a Ki of 0.44 nM. This compound also inhibited bradykinin-induced contraction of epithelium-denuded guinea-pig trachea with a pK(B) of 10.8, but had no effect on carbachol-induced contraction of the trachea even at 10(-6) M. These results indicate that FR167344 has the specific antagonistic activity against guinea-pig tracheal smooth muscle bradykinin receptors.

Analgesics↗