Complete nucleotide sequence of hepatitis B virus.
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Biomedical subjects
Publications and source records attributed to N Fujii.
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A protein with pancreastatin-like immunoreactivity has been isolated and purified from liver metastasis of a patient with insulinoma. NH2-terminal residue analysis, in conjunction with the use of antibodies that are specific for the C-terminal amide peptide of porcine pancreastatin, identified this protein as a 186-amino-acid protein corresponding to human chromogranin A-116-301 (the fragment corresponding to the positions from 116 to 301 of human chromogranin A). Digestion of this protein with trypsin yielded a 48-amino-acid peptide with the retention of full pancreastatin activity. Serum from patient with insulinoma contains a peptide specie(s) that comigrates with the 48-amino-acid pancreastatin, suggesting that this peptide might be a physiologically important circulation form of pancreastatin in humans. A sensitive radioimmunoassay was established using antibody developed against a synthetic 29-amino-acid peptide amide of pancreastatin. Immunocytochemical staining revealed that a major population of human pancreatic islet cells were immunoreactive to the antiserum but with varying intensity of staining. Pancreastatin-like immunoreactivity was not observed in exocrine acinar cells.
A sensitive and specific microenzyme immunoassay (EIA) procedure for porcine brain natriuretic peptide (BNP)-like immunoreactivity has been developed. Enzyme-labeled antigen was prepared by conjugation of synthetic BNP with beta-D-galactosidase using N-(epsilon-maleimidocaproyloxy)succinimide method. Using a second antibody-coated immunoplate, the minimum amount of BNP-like immunoreactivity (BNP-LI) detectable by this assay system was 1.6 fmol/well. When porcine BNP-LI in porcine plasma was assayed by the present method levels between 1 and 8 pmol/l were detected. Gel filtration of porcine plasma extracts on Sephadex G-25 revealed the presence of two immunoreactive peaks; one eluted at a position identical with that of BNP-26 and the other eluted earlier, close the position of BNP-32.
A C-terminal fragment of rat pancreatatin, a 26 residue peptide amide and a fragment without a C-terminal amide were synthesized by Fmoc-based solid phase methods and their biological activities were compared. The rat C-terminal fragment inhibited pancreatic exocrine secretions produced by the intravenous injection of 2-deoxy-D-glucose (a central vagal nerve stimulation), whereas the fragment without a C-terminal amide showed no effect on pancreas. These results indicate that the C-terminal amide of this peptide is necessary to reveal its biological activity.
Effects of synthetic rat pancreastatin C-terminal fragment on both exocrine and endocrine pancreatic functions were examined in rats, in vivo and in vitro. Pancreastatin (20, 100 pmol, 1 nmol/kg/h) significantly inhibited CCK-8-stimulated pancreatic juice flow and protein output in a dose-related manner, in vivo. The inhibitory effect on bicarbonate output was not statistically significant. Pancreastatin did not significantly inhibit basal pancreatic secretions in vivo, and did not inhibit amylase release from the dispersed acini, in vitro. Insulin release stimulated by intragastric administration of glucose (5 g/kg) was significantly inhibited by pancreastatin (1 nmol/kg/h), in vivo. Plasma glucose concentrations were increased by pancreastatin infusion, but the increase was not statistically significant. Furthermore, pancreastatin inhibited insulin release from isolated islets, in vitro. Synthetic rat C-terminal pancreastatin fragment has bioactivities on both exocrine and endocrine pancreatic functions in rats.
We have found a novel type of Ca2(+)-activated neutral protease in rat brain cytosol which cleaves -Tyr-Arg-containing calpastatin fragments to release the neuropeptide kyotorphin. This enzyme was purified about 26,000-fold by column chromatography as follows: DE52 cellulose, Ultrogel AcA 44, thiopropyl-Sepharose 6B, second DE52 cellulose, Ultrogel AcA 34, and blue Sepharose CL-6B. The molecular mass of the enzyme was estimated to be 65-75 kDa by gel filtration. The purified enzyme gave a single band of 74 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Some properties of this enzyme were similar to those of the calpains, i.e. an absolute requirement for Ca2+, maximal activity at neutral pH, and inhibition by sulfhydryl reagents such as p-chloromercuriphenylsulfonic acid and N-ethylmaleimide. However, it differs from the calpains in that it possesses no caseinolytic activity, separates from the calpains on the first DE52 column, and is insensitive to leupeptin and E-64 (N-[N-(L-3-trans-carboxyoxrian-2-carbonyl)-L-leucyl]agmatine). Thus, the molecular mass, the substrate specificity, the chromatographic behavior, and the inhibitor spectrum all suggest that this enzyme is a novel type of Ca2(+)-activated neutral protease.
The receptor binding of CCK analogues was determined in terms of the inhibition of [125I]CCK binding in isolated rat pancreatic acini. The inhibition curve produced by CCK-8 showed the same feature as that produced by synthetic human CCK-33. The relative potency values of CCK analogues to half-maximally inhibit specific CCK binding were calculated; CCK-8 was equal to human CCK-33, 3-fold stronger than natural porcine CCK-33 and 39, and 700-fold stronger than the unsulphated form of synthetic human CCK-33. Our data suggest that CCK-33, one of the longer molecular forms of CCK, is as important as CCK-8 in the mechanism of physiological actions of CCK.
We made use of two-color flow cytometry to examine thymic lymphoid cells from patients with myasthenia gravis. The CD4+CD8- cells and the CD4-CD8+ cells were significantly increased in the thymus from the patients, compared with findings in the control samples. Conversely, the CD4+CD8+ cells were significantly decreased. Significant increases in CD1-CD3+ cells and significant decreases in CD1+CD3- cells were noted. The percentage of CD45R+ cells also increased. There were no increases in activated T lymphocytes, defined as CD4+DR+ cells, CD8+DR+ cells, or IL2R+ cells. We conclude that the proportion of T lineage lymphocytes that are differentiated is increased in the thymus of patients with myasthenia gravis, and could reflect accelerated differentiation.
The action mechanism of hPTH and hPTHrP-(1-34) on phosphate uptake in opossum kidney (OK) cells was studied using [Nle8,18Tyr34]hPTH-(3-34)-NH2, a potent competivie inhibitor of adenylate cyclase-coupled PTH receptor. We examined the effects of hPTH-(1-34), hPTHrP-(1-34), and hPTH-(3-34) separately or in combination on the change in renal cyclic AMP production and phosphate uptake in OK cells. Both hPTH-(1-34) and hPTHrP-(1-34) stimulated intracellular cyclic AMP production to the same degree at concentrations between 10(-10) and 10(-7) M and inhibited phosphate uptake equipotently on a molar basis (27.5 +/- 2.0 and 33.2 +/- 1.2% inhibition at 10(-7) M, respectively). Both exogenous addition of (Bu)2cAMP and endogenous stimulation of cAMP by forskolin inhibited phosphate uptake in a dose-dependent manner. Cyclic AMP production induced by either hPTH-(1-34) or hPTHrP-(1-34) was inhibited by both [Nle8,18Tyr34]-hPTH-(3-34)-NH2 and [Tyr34]-hPTH-(7-34)-NH2. However, [Nle8,18Tyr34]hPTH-(3-34)-NH2 and [Tyr34]-hPTH-(7-34)-NH2 inhibited hPTH-induced cAMP production more strongly. The inhibitory action of phosphate uptake by hPTH-(1-34) and hPTHrP-(1-34) was prevented in the presence of a 100-fold greater concentration of [Nle8,18Tyr34]hPTH-(3-34)-NH2. The antagonistic action of [Nle8,18Tyr34]hPTH-(3-34)-NH2 on the inhibition of phosphate uptake induced by hPTH-(1-34) and hPTHrP-(1-34) became weaker with time (0-120 minutes), and [Nle8,18Tyr34]hPTH-(3-34)-NH2 did not antagonize the inhibition of phosphate uptake induced by hPTHrP-(1-34) at 120 minutes of incubation.(ABSTRACT TRUNCATED AT 250 WORDS)
Zymosan-induced chemiluminescence was investigated in whole blood and in neutrophils: in both, the peak count was frequently elevated in Behçet's disease, and was significantly higher than in healthy controls; similarly the peak time was shorter. There were more uncommon serotypes of Streptococcus sanguis in the oral flora of patients with Behçet's disease. Common serotypes were present in the flora of healthy controls, but not in patients with the disease. The percentage of Strep. sanguis in the oral flora was significantly correlated with the level of chemiluminescence response. Thus infection with uncommon serotypes of Strep. sanguis may play a role in the aetiology of Behçet's disease.
The effects of the C-terminal fragment of rat pancreastatin on exocrine pancreatic secretions induced by several neural stimulations [IV injection of 75 or 15 mg/kg of 2-deoxy-D-glucose (central vagal nerve stimulation), injection of 2 mg of cisapride (proposed to elicit acetylcholine release from cholinergic nerve ending), and infusion of 1 or 3 mg.kg-1.h-1 of bethanechol (direct stimulation of acinar cells)] were examined in conscious rats. Rats with external bile and pancreatic fistulae were used. All the stimulations caused significant increases in pancreatic exocrine secretions. Pancreastatin at 100 pmol.kg-1.h-1 inhibited pancreatic secretions stimulated by IV injection of 2-deoxy-D-glucose but not those induced by the infusion of bethanechol or the injection of cisapride. Because these findings showed that pancreastatin inhibited pancreatic secretions induced by central vagal nerve stimulation, the effect of pancreastatin on cholecystokinin-stimulated pancreatic secretions in vagotomized rats was examined. Pancreastatin at 100 pmol.kg-1.h-1 did not inhibit pancreatic secretions stimulated by cholecystokinin octapeptide at 100 pmol.kg-1.h-1 in conscious rats after bilateral truncal vagotomy. These results suggest that pancreastatin inhibits pancreatic exocrine secretions by inhibiting vagal efferent nerve activity.
Leptospiral lipopolysaccharides (LPSs) extracted from Leptospira interrogans serovars copenhageni and hebdomadis were tested for the ability to induce macrophage activation. In-vitro analysis showed that each leptospiral LPS was a potent activator to macrophages. After stimulation with the LPSs, interleukin-1 (IL-1) secretion, interferon (IFN) production and chemiluminescence (CL) response were induced. Intravenous high-dose injection of the leptospiral LPSs induced various lesions such as necrosis of the liver, and the LPSs were detected in macrophages in the liver, spleen and lymphnodes by immunohistochemical examination. Enhancement of macrophage activity in mice inoculated with low doses of leptospiral LPS was recognized. The macrophages of the LPS-treated mice showed a significantly higher bactericidal action than those of control mice. The beta-galactosidase and nitroblue tetrazolium (NBT) positive cells in macrophages of the LPS-treated mice increased significantly. In the NBT reduction test after phagocytosis of latex beads or Salmonella typhimurium, the macrophages of the LPS-treated mice showed a significantly higher activity than those of control mice.
We have examined the effect of synthetic human cholecystokinin (CCK-33 and CCK-8) on pancreatic blood flow and protein output in anesthetized dogs. Human CCK-33 and CCK-8 increased pancreatic blood flow and protein output in a dose-related manner. There were no significant differences in increasing pancreatic blood flow between human CCK-33 and CCK-8, and increases in blood flow were closely related to the increase of the pancreatic enzyme secretion. L-364,718 (20 nmol/kg) caused a potent inhibition of CCK-stimulated pancreatic blood flow as well as protein output. The degree of inhibition by L-364,718 was dependent on the amount of CCK infused. This study demonstrates that increasing effect on pancreatic blood flow may be one of the biological actions of CCK mediated via CCK receptor. The CCK-33, one of longer molecular forms of CCK, is an important biological stimulator of pancreatic blood flow as well as of exocrine pancreatic secretion.
Persistent infections with several strains of mumps virus (strains Torii and Miyahara), measles virus (strains Edmonston, CAM-70, AIK-C and Schwarz) and subacute sclerosing panencephalitis (SSPE) virus (Hälle and Mantooth) were established in various cell lines (FL, KB, A549, SK-AS, 293, K562, Ramos and NC-37). Oligo-2',5'-adenylate synthetase activity was demonstrated to be only slightly induced by interferon in cytoplasmic and nuclear fractions of cell lines persistently infected with mumps virus. In these cells, resistance to vesicular stomatitis virus infection was not induced by interferon treatment. Treatment of the persistently infected cells with interferon for 10 and 24 h did not stimulate an increase in the amount of synthetase mRNA. In cells persistently infected with measles and SSPE viruses, reduced induction of the enzyme varied with host cell types. Induction of the enzyme was not found in K562, SK-AS and KB cells, but was recognized in NC-37 and FL cells.
Chromosomal DNAs were extracted from toxigenic three Clostridium botulinum type E strains isolated from food-borne botulism. After digestion by EcoRI, the fragments were cloned into Escherichia coli by using bacteriophage lambda gt11 and screened with monoclonal antibody recognizing the light chain component of botulinum type E toxin. The fragments (about 1 kbp size) cloned from each strain were recloned into a plasmid vector pUC118. The E. coli cells transformed with the recombinant plasmids produced 33 kDa protein with or without IPTG (isopropyl-beta-D-thiogalactopyranoside) which reacted with the monoclonal antibody. The nucleotide sequences of the cloned EcoRI fragments from the three type E strains were identical and contain the 5'-terminal region of the type E toxin gene. It was also found that there exist several highly homologous nucleotide sequences among the botulinum types A, C and E, and tetanus toxin genes in both translated and untranslated regions.
In Clostridium botulinum types C and D, phage conversion to toxin and hemagglutinin (HA) production has been reported. DNA was extracted from a converting type C Stockholm phage, c-st, and a fragment (7.8 kilobase pairs) coding for the parts of both toxin and HA was cloned. The gene for HA was recloned, and the complete nucleotide sequence was determined. The molecular mass of this gene product was 33 kilodaltons, and it showed HA activity. The HA preparation partially purified from a type C Stockholm culture demonstrated two major bands (33 and 53 kilodaltons) on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with or without reducing agent. The amino acid sequence of the N terminus of the 33-kilodalton component of the native HA preparation, which was determined by a direct protein microsequencing procedure, was identical to that deduced from the nucleotide sequence of cloned HA gene. These data indicate that the cloned gene product (33 kilodaltons) is an important component of HA.
We measured serum inhibin levels in eight untreated patients with prostatic cancer undergoing castration by RIA using an antiserum against 31-kDa bovine follicular fluid inhibin. The inhibin concentrations in testicular tissue and spermatic venous blood were also measured in six of these patients. Serum inhibin levels (mean +/- SD, 377.8 +/- 212.1 U/L), declined rapidly after castration (15 min after, 233 +/- 171.4; 30 min, 224.6 +/- 156.6; 1 h, 181.5 +/- 95.9; 2 h, 174.3 +/- 69.4; 4 h, 122 +/- 6.4; 6 h, less than 120). High concentrations of inhibin were detected in testicular tissue (31,360 +/- 15,180 U/kg), and the levels in spermatic venous blood (3,178.3 +/- 1,386.8 U/L) were approximately 10 times greater than those in peripheral blood (385.5 +/- 233.1 U/L). Testosterone levels were 1,968.2 +/- 992.3 nmol/kg in testicular tissue and approximately 100 times greater in spermatic venous blood (1,631.6 +/- 389.7 nmol/L) than in peripheral blood (18.0 +/- 4.4 nmol/L). These results suggest that circulating inhibin in men mainly originates from testis and that one of the routes of secretion is via the bloodstream.