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Biomedical subjects

E Nakajima

Publications and source records attributed to E Nakajima.

At least 73 records · Page 4Linked to original sources
PubMed1979

Whole-body autoradiography of bumetanide-14C in dogs by round saw method.--A combined method of autoradiography and tissue radioassay--.

The distribution of a new potent diuretic, Bumetanide, in dogs was studied by means of a combined method of whole-body autoradiography and tissue radioassay, after oral administration of Bumetanide-14C to five young beagle dogs (ca. 1.2 kg). A round saw method developed by Kalberer was applied to obtain frozen slices of dog whole-body with a thickness of 3 mm. After exposure to X-ray films from both sides of the slices at -60 degrees C, frozen samples of the main tissues as well as the blood, urine, bile and intestinal contents were obtained to be assayed for radioactivity and to be analyzed for metabolites by TLC. The advantages of the round saw method (thick slices) in larger animals as dogs and monkeys as compared to the conventional microtome method (thin sections) were pointed out and discussed.

Administration, Oral↗
PubMedDate not supplied

Expression of calpain small subunit 2 in mammalian tissues.

PURPOSE: The purpose of the current experiments was to more closely define the distribution and the function of calpain small subunit 2 (css2). Css2 is a newly discovered regulatory protein for the calcium activated proteases, mu- and m-calpains. METHODS: Tissues from rat, monkey, and man of various ages were used to determine expression patterns of css2 by relative quantitative RT-PCR using 18S rRNA as an endogenous standard. Recombinant css2 and the 80 kDa catalytic subunit of m-calpain (80 kDa/css2) were co-expressed in Escherichia coli. Casein zymography was used to measure the enzymatic activity of 80 kDa/css2 proteins. Lens alpha-crystallin and beta B1-crystallin were used as substrates to determine proteolysis by 80 kDa/css2. Computer-based homology modeling was used to predict interactions between the traditional small subunit (css1) or css2 with the 80 kDa catalytic subunit. RESULTS: Css2 appears to be a functional equivalent of css1 in vitro in that the calcium-dependent proteolytic activity of 80 kDa/css2 was similar to recombinant m-calpain (80 kDa/css1). In rat and human lens, css2 transcripts increased with age, whereas css1 transcripts decreased with age. Human beta B1-crystallin and rat alpha A-crystallin were cleaved similarly by 80 kDa/css2 and 80 kDa/css1. Interestingly, alpha A-insert crystallin was not hydrolyzed when css2 was substituted for css1 in the calpain dimer, suggesting that css2 may perform different functions from css1 in terms of proteolysis of lens crystallins during maturational growth of the lens. Css2 may also assist in the proper folding of the 80 kDa subunit and regulate protease activity in the absence of calcium. CONCLUSIONS: The wide distribution of css2 transcripts in rat and monkey suggested that css2 is a second, widely distributed (rather than tissue-specific) calpain small subunit, in addition to the long-recognized css1. Further studies at the protein level will indicate if css2 has unique functions apart from css1.

Adolescent↗
PubMedDate not supplied

Effects of benzene in a micronucleus test on peripheral blood utilizing acridine orange-coated slides.

A micronucleus test was conducted on the peripheral blood of mice and rats utilizing acridine orange-coated slides (AO-coated method) after oral administration of benzene. Blood was sampled at 0, 24, 48, and 72 h after administration of benzene at doses of 500, 1000, and 2000 mg/kg in both mice and rats. The highest occurrence of micronucleated reticulocytes (MNRETs) was observed at 48 h after administration in both species. Species differences was found in the frequency of MNRETs, with the number being lower in rats than in mice. The present results indicate that the micronucleus test can easily detect chromosome aberrations in peripheral blood induced by benzene administration in both mice and rats. Furthermore, the AO-coated method used in this study was simpler to perform and allowed for easier detection of the effect than the conventional method.

Acridine Orange↗