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Biomedical subjects

H Maeda

Publications and source records attributed to H Maeda.

At least 1,333 records · Page 74Linked to original sources
PubMed1981

[Clinical evaluation of amikacin in severe infections with hematological malignant diseases (author's transl)].

Investigation was made on absorption, excretion and clinical responses following intravenous drip infusion of amikacin (AMK) and the following results were obtained. 1) Serum concentrations of AMK were determined after completion of a 1 hour-course of its intravenous drip infusion at a dose of 200 mg, involving 2 patients with normal renal function and 1 patient with impaired renal function. In the patients with normal renal function, a mean peak serum concentration of 15.9 micrograms/ml was reached at the termination of the intravenous drip infusion and, then, gradually declined to 0.97 microgram/ml at 6 hours after completion of the intravenous drip infusion. The half-lives were 1.64 and 1.41 hours, respectively. In the patients with impaired renal function, the elimination of AMK from blood flow was markedly delayed and the serum concentration was 5.52 micrograms/ml even at 6 hours after completion of the intravenous drip infusion. The half-life was prolonged, its value being 5.98 hours. 2) The mean urinary excretion rate for the patients with normal renal function was 67.7% within 7 hours, while the patient with impaired renal function had a lower rate of 14.0%. 3) Ten infectious patients with hematological malignant diseases were treated with AMK intravenous drip infusion. Clinical responses were excellent in 6, good in 2, fair in 1 and poor in 1. Thus, 80% of the patients responded to AMK. 4) In order to check the side effects of AMK, investigation was made on the results of various clinical laboratory tests and the subjective and objective findings. But, no side effects attributed to AMK were observed. Therefore, it is thought that the intravenous drip infusion of AMK will be very useful when attention is paid to infusion time, dose and interval.

Adolescent↗
PubMed1980

Interaction of chymotrypsinogens with alpha 1-protease inhibitor.

In a previous report [Largman, C., Brodrick, J.W., Geokas, M.C., Sischo, W.M., & Johnson, J.H. (1979) J. Biol. Chem. 254, 8516-8523] it was demonstrated that human proelastase 2 and alpha 1-protease inhibitor react slowly to form a complex that is stable to denaturation with sodium dodecyl sulfate and beta-mercaptoethanol and that the zymogen can be recovered from the isolated complex following dissociation by hydroxylamine. The present report demonstrates that bovine chymotrypsinogen A reacts with human alpha 1-protease inhibitor in a very similar manner. The rate of complex formation was measured by two methods. In the first, the reaction was followed by determining the loss of the inhibitory activity of alpha 1-protease inhibitor as a function of time. A second-order rate constant for complex formation formation (pH 7.6, 36 degrees C) of 12.9 +/- 2.4 M-1s-1 was obtained. In the second procedure, the reaction of fluorescein isothiocyanate labeled chymotrypsinogen A with alpha 1-protease inhibitor was measured by fluorescence polarization. A second-order rate constant (pH 7.6, 37 degrees C) of 13.9 +/- 2.1 M-1s-1 was obtained. The rate of complex formation is approximately 10(-5) of that measured for the reaction of bovine chymotrypsin with alpha 1-protease inhibitor. Dissociation of the complex was not observed after dilution or the addition of excess bovine alpha-chymotrypsin. As judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis experiments, human chymotrypsinogens I and II react with alpha 1-protease inhibitor at rates that are approximatley equivalent to that determined for bovine chymotrypsinogen A. In contrast, bovine trypsinogen reacts very slowly with alpha 1-protease inhibitor, at a rate that is at most 10(-2) of that of bovine chymotrypsinogen A. These results suggest that zymogens react with alpha 1-protease inhibitor by virtue of partially formed active sites and that the potential active-site specificity of the zymogen in part determines the rate of complex formation.

Animals↗
PubMed1980

An electrophysiological study of inputs to neurons of the ventral tegmental area from the nucleus accumbens and medial preoptic-anterior hypothalamic areas.

Extracellular recordings were obtained from neurons in the ventral tegmental area (VTA) of urethane-anesthetized rats. Neurons were divided into two types based on the latencies of antidromic activation following electrical stimulation of the nucleus accumbens (NAcc), and on the durations of action potentials. Type A neurons had longer latencies for antidromic activation (mean 15.9 msec) and longer durations of action potentials (> 2.6 msec), while type B neurons had shorter latencies (mean 4.5 msec) and shorter duration of action potentials (< 2.6 msec). Electrical stimulation of the medial preoptic-anterior hypothalamic areas (mPOA-AHA) and NAcc produced the following effects on the two types of VTA neurons: (i) the majority of both type A and B neurons were suppressed by mPOA-AHA stimulation with onset latencies of less than 10 msec; (ii) 42% of type B neurons were also suppressed by NAcc stimulation, with onset latencies of less than 10 msec; (iii) type A neurons were suppressed (33%) or activated (43% by NAcc stimulation, the onset latencies usually being longer than 10 msec; (iv) 71% of type A neurons tested had convergent inputs from the mPOA-AHA and NAcc, usually suppressed-suppressed or suppressed-activated, while 45% of type B neurons had convergent inputs from these two areas, usually suppressed-suppressed.

Animals↗
PubMed1980

Systemic hyalinosis or juvenile hyaline fibromatosis. Ultrastructural and biochemical study of cultured skin fibroblasts.

Biochemical examinations of a hyalinized skin tumor of systemic hyalinosis (juvenile hyaline fibromatosis) revealed an increase in chrondroitin sulfate synthesis by skin fibroblasts with an enlarged, rough surfaced endoplasmic reticulum as well as an increase in chondroitin sulfate content. Thse results indicate that systemic hyalinosis is a connective tissue disorder characterized by abnormal GAG synthesis of fibroblasts.

Adult↗