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Biomedical subjects

A Nakano

Publications and source records attributed to A Nakano.

At least 19 recordsLinked to original sources
PubMed1992

Tetronothiodin, a novel CCKB receptor ligand, antagonizes cholecystokinin-induced Ca2+ mobilization in a pituitary cell line.

We found a novel nonpeptide CCKB receptor antagonist, tetronothiodin (Ro 09-1468), in the culture broth of Streptomyces sp. NR0489. The structure of the compound (C31O8H38S), which has a 19-membered ring with an alpha-acyltetronic acid and tetrahydrothiophene moiety, is completely different from that of any known CCK receptor antagonist. Tetronothiodin inhibited [125I]CCK-8 binding to rat brain CCKB receptors with an IC50 of 3.6 nM, whereas it showed only weak affinity for rat CCKA receptors (IC50 = 70 microM). As demonstrated autoradiographically, tetronothiodin concentration dependently inhibited [125I]CCK-8 binding to CCKB receptors in rat forebrain slices. The effects of tetronothiodin on cytosolic Ca2+ concentrations in GH3 cells, a rat anterior pituitary tumor cell line, were investigated with the fura-2 method. Tetronothiodin inhibited CCK-8-induced Ca2+ mobilization without affecting basal cytosolic Ca2+ concentrations. In conclusion, tetronothiodin is a new, potent and highly selective CCKB receptor antagonist. It is a useful tool for investigating the pharmacological and physiological roles of CCKB receptors.

Animals↗
PubMed1992

Neurocalcin: a novel calcium-binding protein from bovine brain.

A novel calcium-binding protein (molecular weight 23,000-24,000, pI 5.3-5.5), which we term neurocalcin, was identified in bovine brain. Using calcium-dependent drug affinity chromatography ((S)-P-(2-aminoethyloxy)-N-[2-(4-benzyloxycarbonylpiperazinyl++ +)-1-(P- methoxybenzyl)ethyl]-N-methylbenzene-sulfonamide dihydrochloride, W-77, -coupled Sepharose 6B), we purified neurocalcin from bovine brain. The partial amino acid sequence of neurocalcin revealed it to be an as yet unidentified protein with three putative calcium binding sites (EF-hands). Further purification and sequence analysis demonstrated the presence of four isoprotein forms designated alpha, beta, gamma 1, and gamma 2. When the 165 sequenced residues of neurocalcin beta are compared with sequences of other proteins, neurocalcin beta has a 38.2% sequence homology with visinin and 45.5% with recoverin (Yamagata, K., Goto, K., Kuo, C.-H., Kondo, H., and Miki, N. (1990) Neuron 2, 469-476; Dizhoor, A. M., Ray, S., Kumar, S., Niemi, G., Spencer, M., Brolley, D., Walsh, K. A., Philipov, P. P., Hurley, J. B., and Stryer, L. (1991) Science 251, 915-918). Both visinin and recoverin are expressed specifically in retinal photoreceptors and are not found in brain. Unlike visinin and recoverin, neurocalcin is purified not only from retina but also from bovine brain. Our results suggest that neurocalcin is a recoverin-like protein expressed in bovine brain.

Amino Acid Sequence↗
PubMed1992

Purification of the murine heat-stable antigen from erythrocytes.

The rat anti-mouse erythrocyte (MRBC) monoclonal antibody (mAb), R13, has been developed. The MRBC membrane protein recognized by R13 (R13-Ag) can be purified by loading the butanol-extracted MRBC membrane solution on a R13-conjugated Cellulofine column in the presence of 0.1% CHAPS followed by elution with 1% CHAPS. The amino acid sequence of the affinity-purified R13-Ag corresponded to that predicted from the cDNA for the murine heat-stable antigen. It was revealed that the actual heat-stable antigen was composed of 27 amino acids.

Amino Acid Sequence↗
PubMed1992

Neurocalcin, a novel calcium binding protein with three EF-hand domains, expressed in retinal amacrine cells and ganglion cells.

Neurocalcin (molecular weight 23,000 and 24,000) is a newly identified Ca2+ binding protein with three EF-hand domains and has a strong amino acid sequence homology with visinin and recoverin (Terasawa, M., Nakano, A., Kobayashi, R., and Hidaka, H. J. Biol. Chem. In press). We produced antibody against neurocalcin. Immunoblotting showed the presence of neurocalcin in bovine retina as well as brain, suggesting that neurocalcin was a neuron specific Ca2+ binding protein. Immunohistochemistry revealed the expression of neurocalcin in retinal amacrine cells and ganglion cells but not in the photoreceptor layer. This distribution of neurocalcin was quite different from that of visinin and recoverin. Our results suggest that neurocalcin may play an important role in a Ca2+ signal pathway of the nervous system.

Animals↗
PubMed1992

Purification, gene cloning, and gene disruption of the transcription elongation factor S-II in Saccharomyces cerevisiae.

Saccharomyces cerevisiae S-II was purified to near homogeneity as a protein stimulating RNA polymerase II. Four of seven lysyl endopeptidase-digested fragments of S-II were located in the PPR2 sequence reported previously. Analysis of a genomic clone of S-II revealed that S-II and PPR2 are the same protein consisting of 309 amino acid residues, and frame shifts were found in the sequence of PPR2 gene reported previously. Yeast S-II and mouse S-II showed high similarity in their amino acid sequences, especially in their amino-terminal and carboxyl-terminal regions. A gene disruption experiment showed that an S-II null mutant was not lethal under usual growth conditions, indicating that S-II is not essential for the growth of yeast.

Amino Acid Sequence↗
PubMed1992

Mononuclear cell response in the liver of mice infected with hepatotoxigenic Campylobacter jejuni.

Intragastric inoculation with hepatotoxigenic strains of Campylobacter jejuni led to the death of mice during the late phase of infection. Histological study disclosed a massive infiltration of mononuclear cells in the liver, mimicking intrahepatic hypersensitivity. Neither enterotoxigenic nor enteroinvasive Escherichia coli induced such a lesion. However, the same histopathological change was induced by injecting the hepatotoxic factor of hepatotoxigenic C. jejuni intravenously on two occasions separated by 14 days. Neither a single injection of an increased dose of the hepatotoxic factor nor two injections, the second of which was heat-inactivated, induced this change. Pre-treatment with rabbit antibody to the hepatotoxic factor inhibited the development of the hepatic lesion. These results suggest that C. jejuni-induced hepatic lesions in mice may be caused, at least in part, by the active moiety of the hepatotoxic factor. The possible mechanisms by which the toxic factor induces hepatitis as a consequence of hypersensitivity are discussed in relation to Guillain-Barré syndrome and Reiter's syndrome associated with C. jejuni enteritis.

Animals↗
PubMed1992

Patients with homocystinuria: high metal concentrations in hair, blood and urine.

Patients with homocystinuria excrete a large amount of metal in their urine. Homocysteine similar to penicillamine, administration to methylmercury treated rats resulted in a large amount of urinary methylmercury excretion. These results suggested that the total metal amounts in the whole body of patients with homocystinuria might be decreased. However, actually metal concentrations in hair and plasma of these patients were higher than those of normal controls. High plasma and hair metal levels are not accounted for in patients with homocystinuria. The physiological metal excretory mechanism in which small amounts of metals bind to the small, plasma molecular substances filter through the kidney and emerge in the urine is necessary for reconfirmation. Strongly perturbed metal metabolism exists in the patients with homocystinuria.

Adult↗
PubMed1992

Follow up study of renal tubular dysfunction and mortality in residents of an area polluted with cadmium.

A retrospective cohort study was conducted to investigate the association between cadmium induced renal tubular dysfunction and mortality. A total of 230 subjects aged 40 or older and living in a cadmium polluted area in Kosaka Town, Akita Prefecture, Japan, were studied at least once between 1975 and 1977 and again in 1990. Urinary beta 2-microglobulin and total amino nitrogen concentrations were significantly related to mortality from all causes in women. The finding supports the idea that cadmium induced kidney damage is a factor associated with mortality in a general population exposed to environmental cadmium.

Adult↗
PubMed1992

[Concentration of trace elements in hair from children living in a Keshan disease district in China].

The hair from 9 children living in a Keshan disease prevalent district and from 10 children living in a Keshan disease non-prevalent district in China was analyzed. At the same time, the hair from 35 children of the same age residing in Tsukuba district in Japan was analyzed for comparison of the concentration of essential trace elements with that of children living in the Keshan disease prevalent district. Se concentration was determined by a fluorophotometric method and 16 other elements were analyzed by ICP emission spectrometry. Hg was analyzed by the heating evaporation method and by neutron activation analysis. The Se concentration in the hair of children living in the prevalent district was very low, being one-tenth that of the Japanese. The Ni concentration was particularly low in the prevalent district, and it determined to study more about the effects of Ni deficiency on health. In the prevalent district, Mg and Ca levels were low and those of Pb, Fe, Al, Ti were relatively high. Mn concentrations of both districts in China were very high when compared to the Japanese. The results of this study showed that the low Se concentration in Keshan disease is in agreement with previously reported data. Ecological factors, including nutrition were considered to be important in the etiology of this disease.

Adolescent↗
PubMed1992

Hepatic encephalopathy secondary to a large-caliber porto-hepatic venous shunt. A case report.

A case of hepatic encephalopathy secondary to a large-caliber porto-hepatic venous shunt in a 61-year-old woman with gastric cancer is reported. Mild confusion, flapping tremor and hyperammonemia were noted preoperatively. Abdominal ultrasonography showed a large-caliber porto-hepatic venous shunt in the left lateral segment of the liver. Percutaneous transhepatic portography and superior mesenteric angiography were confirmatory. Intraoperative portal scintigraphy was performed before and after temporary shunt occlusion to measure the intrahepatic shunt rate, which decreased markedly after occlusion. Portal pressure was also measured, and increased only slightly after occlusion. Left lateral hepatic segmentectomy, and subtotal gastrectomy with splenectomy were performed. Hepatic encephalopathy resolved postoperatively. The shunt was thought to be acquired. The relevant reports on large-caliber porto-hepatic venous shunts in the literature are reviewed.

Female↗
PubMed1992

[Pulmonary clearance of 99mTc-DTPA aerosol in patients with progressive systemic scleroderma].

Alveolar epithelial permeability was assessed in 32 patients with progressive systemic scleroderma (PSS), using 99mTc-DTPA aerosol. Immediately after the inhalation of 99mTc-DTPA aerosol for 3 to 6 minutes under normal tidal breathing, lung was imaged sequentially for 30 minutes from the posterior by a gamma camera and exponential fitting was processed on the time activity curve. T1/2 (min) was used as a parameter for the evaluation of permeability of alveolar epithelium. Patients with collagen disease showed shorter T1/2 (T1/2 = 43.7 +/- 23.8 min) than the normal volunteers (T1/2 = 76.8 +/- 8.7 min). No significant difference was observed between patients with or without interstitial changes on the chest CT. Significant correlation was not observed between T1/2 and %VC or %DLco. In 8 cases, studies were repeated in the interval of 3 to 19 months. Improvement of T1/2 was seen in 4 cases, independent of CT findings. These results suggest that 99mTc-DTPA aerosol clearance study provides information independent from other lung examinations, and may be useful for the assessment of lung interstitial changes in patients with PSS.

Administration, Inhalation↗
PubMed1992

[A cross-sectional study of lipid peroxide levels (plasma TBA levels) in a mass health examination].

Differences in plasma thiobarbituric acid (TBA) levels were studied by sex and age in 1,178 adults (471 males and 707 females) participating in a mass health examination conducted in a town of Kumamoto Prefecture in 1989. The relationships between plasma TBA levels and obesity, the consumption of cigarettes, alcohol, and fish, and various indices for health status derived from the data of physiological examinations were analyzed in age-groups 40-59 and 60-79 for both sexes. The prevalence of abnormal physiological findings by plasma TBA levels were further investigated. The results were as follows; 1. The highest plasma TBA levels for males were observed in the group aged 40-49, with levels gradually decreasing with age thereafter. The plasma TBA levels for females increased with age and the highest levels were obtained at age 60-69. The plasma TBA levels for males were significantly higher than for females at aged 40-49. 2. Plasma TBA levels for both sexes increased with obesity and the amount of fish consumed. 3. Plasma TBA levels in all examined groups had significant and strong positive correlations with serum total cholesterol levels and atherogenic indices, and had significant positive correlations with serum calcium and gamma-GTP levels. 4. A stepwise multiple regression analysis showed that plasma TBA levels for males were associated with serum total cholesterol, gamma-GTP, fish consumption and serum HDL-cholesterol in that order. The levels for female were associated with serum total cholesterol, body mass index, serum HDL-cholesterol and serum calcium in that order. The relationship with serum HDL-cholesterol was a negative correlation. 5. Prevalence of abnormal values of serum total cholesterol, atherogenic index and body mass index were significantly higher in the high-plasma TBA level group than in the group with median-plasma TBA level. These results suggest that plasma TBA levels may be useful as an index of undesirable lipid metabolism. Further studies should be performed to establish the significance of the relation of plasma TBA levels to fish consumption.

Adult↗
PubMed1992

[Assessment of alveolar epithelial permeability in progressive systemic sclerosis (PSS) using 99mTc-DTPA (diethylene triamine penta acetate) aerosol inhalation].

To evaluate alveolar epithelial damage in PSS, we studied pulmonary epithelial permeability by measuring the clearance of inhaled 99mTc-DTPA aerosol and performing thin slice CT scan, pulmonary function tests and right heart catheterization in 28 patients with PSS. The 99mTc-DTPA clearance rate (kep value) in PSS was greater than in 11 non-smoking normal subjects (18.2 +/- 7.63 x 10(-3)/min vs. 9.12 +/- 0.77 x 10(-3)/min, p less than 0.01). In PSS, the kep value did not correlate with age, sex, duration of illness, dermal lesions, % vital capacity, or PaO2. In contrast, the kep value showed significant correlations with %DLco (diffusing capacity for carbon monoxide), extent of interstitial lesions evaluated by CT scan (CT score), and mean pulmonary artery pressure. On the other hand, the kep value was high in some patients with normal CT scan and normal %DLco. These findings indicate that pulmonary interstitial lesions in PSS are accompanied by alveolar epithelial damage, and that the clearance of 99mTc-DTPA may be an early predictor of interstitial change.

Administration, Inhalation↗
PubMed1991

DS28-6, a temperature-sensitive mutant of Chinese hamster ovary cells, expresses key phenotypic changes associated with brefeldin A treatment.

The temperature-sensitive Chinese hamster ovary (CHO) cell mutant DS28-6 has been previously shown to be pleiotropically defective in protein secretion. We have examined the mutant cells to determine the intracellular site of the block in secretion. By transmission electron microscopy a time-dependent disassembly of the Golgi apparatus was found under nonpermissive temperature, which resulted in the loss of the cisternal stack. Complete reorganization of the Golgi apparatus occurred after shift to permissive temperature. Under nonpermissive temperature, a microtubule- and energy-dependent redistribution of Golgi mannosidase II and galactosyltransferase into a pattern characteristic of the endoplasmic reticulum (ER) was observed. Inhibition of protein synthesis by cycloheximide had no influence on Golgi mannosidase II redistribution. Evidence for Golgi apparatus-associated processing of oligosaccharides in the ER was obtained by lectin-gold cytochemistry revealing the presence of the galactose (beta 1----4)N-acetylglucosamine sequence and sialic acid residues. Furthermore, 7-nitrobenz-2-oxa-1,3-diazol-4-yl-tagged ceramide, a lipidic trans-Golgi apparatus marker in CHO cells, exhibited an energy-dependent redistribution into the ER. These effects were fully reversible upon shift to permissive temperature. Thus, mutant DS28-6 cells exhibit key features of the brefeldin A phenotype, which suggests that the observed brefeldin A effects result from interference with a normally occurring cellular process.

Animals↗
PubMed1991

The GTP-binding Sar1 protein is localized to the early compartment of the yeast secretory pathway.

SAR1, the yeast gene which encodes a novel type of small GTP-binding protein, has been shown to be required for protein transport from the endoplasmic reticulum (ER) to the Golgi apparatus. To further the understanding of the function of its product, a lacZ-SAR1 hybrid gene was constructed and a polyclonal antibody was raised against the hybrid protein. This antibody specifically recognizes the SAR1 gene product (Sar1p) as a 23-kDa protein in the yeast cell lysate. We examined the subcellular localization of Sar1p using this antibody. In wild-type cells, Sar1p was predominantly recovered in a rapidly sedimenting membrane fraction that includes the ER. The soluble form of Sar1p was also detected when the protein was overproduced. Immunofluorescence microscopy with the anti-Sar1p antibody showed perinuclear staining that was exaggerated in the ER-accumulating sec18 mutant. Membrane association of Sar1p was shown to be very light. Sar1p was not extracted from the membrane by treatment with alkaline sodium carbonate, and only 1% deoxycholic acid solubilized Sar1p completely. From these results, we suggest that Sar1p is firmly located on the ER membrane where it regulates the ER-Golgi traffic.

Antibodies↗
PubMed1991

SRH1 protein, the yeast homologue of the 54 kDa subunit of signal recognition particle, is involved in ER translocation of secretory proteins.

The function of the SRH1 product, the yeast homologue of the 54 kDa subunit of the mammalian signal recognition particle, has been analyzed using a galactose dependent mutant of the gene. SRH1 has been placed under control of the GAL1 promoter and introduced into a haploid cell that had its chromosomal SRH1 copy disrupted. This mutant grows normally on galactose medium but slows down the growth about 10 h after transfer to glucose medium. At the same time, precursor forms of secretory proteins, alpha-mating factor and invertase, accumulate in the cells. This result indicates that the SRH1 product is involved in translocation of precursors of secretory proteins across the endoplasmic reticulum membrane in yeast cells.

Base Sequence↗
PubMed1991

Establishment of a novel cell line with T-lineage phenotype (HPB-MLp-W) from a non-Hodgkin's lymphoma patient.

We report the characterization of a novel human T-cell line, HPB-MLp-W, which was established from blastic cells of a lymph node specimen from a patient with non-Hodgkin's lymphoma. They demonstrated the T-cell association antigens, CD2 and CD4, but no CD3, CD8, CD1, CD5, CD7 nor T-cell antigen receptor on their cell surfaces. They were also positive for Ia and Ki-1 antigen, and negative for CD25 (Tac-1). The cell line HPB-MLp-W had the same pattern of antigen expression as the patient's cells. Southern-blot analysis of DNA showed a rearrangement of the T-cell receptor-alpha and beta genes. To our knowledge, this is a novel cell line with unique T-lineage marker, to be established from a case of non-Hodgkin's lymphoma.

Antigens, CD↗