PubMed Health⌕ Search

Biomedical subjects

H Nagashima

Publications and source records attributed to H Nagashima.

At least 181 records · Page 10Linked to original sources
PubMed1988

Interferon production under the control of heterologous inducible enhancers and promoters.

In a search for a useful enhancer to control expression of interferon (IFN) gene in mammalian cells, mouse IFN-beta cDNA ligated 3' downstream to the enhancer-promoter of either mouse metallothionein-I (MT-I) or Drosophila heat shock protein (HSP) was introduced into various cultured cells by calcium-phosphate precipitation method, and the level of IFN transiently produced was compared. In the case of the MT-I enhancer-promoter, low levels of IFN were produced without induction (0-21 IU/ml) and the level increased 5-50 times by heavy metals. In contrast, the basal level of expression of the HSP enhancer-promoter was very low and its expression was increased several hundred to thousand times by heat shock or arsenite. Thus the HSP enhancer-promoter appears to be a potent inducible element with very low basal level and high inducibility.

Animals↗
PubMed1988

The effect of digoxin on contractility and fatigue of isolated guinea pig and rat hemidiaphragms.

Digoxin could improve diaphragm contractility and fatigability if inhibition of sodium-potassium adenosine triphosphatase enhances calcium influx from extracellular sources, or it could impair contractility and worsen fatigue if it impairs maintenance of the membrane potential. We studied the effects of digoxin on isometric force production, fatigue, and recovery in isolated, directly stimulated, guinea pig and rat diaphragms. Digoxin had no effect on maximal twitch or tetanic tensions compared with control diaphragms in either rat (2 ng/ml to 20 micrograms/ml) or guinea pig (2 ng/ml to 2 micrograms/ml) hemidiaphragms. Digoxin worsened high frequency fatigue and impaired recovery from fatigue in guinea pigs (200 ng/ml to 2 micrograms/ml) but not in rat (2 micrograms/ml) hemidiaphragms. We conclude that digoxin has no effect on diaphragm contractility. Hypopolarization of the membrane potential is the likely cause for the increased fatigability. The difference in responsiveness between species is likely due to insensitivity of rat sodium-potassium adenosine triphosphatase to digoxin.

Aminophylline↗
PubMed1988

Sexing of half-embryos produced by microsurgical bisection of mouse morulae and production of chimeric mouse of defined sex composition by aggregating two sexed half-embryos.

Using the halved morulae of mice obtained with microsurgical technique, the following two experiments were performed. 1) Sexing of half-embryos by chromosomal analysis and transfer of the half-embryos after determining the sex of the other monozygotic half. One half of the bisected embryo was cultured in Colcemid solution (0.04 micrograms/ml) to be ensured for chromosomal preparation. More than 50% (152/270) of the blastulated embryos from the halves could be sexed by direct sex chromosome analysis. Thirty-nine of the half-embryos of which the co-twin halves were sexed, were transplanted in to the uterine horns of 18 pseudopregnant mice, and twelve became pregnant. The autopsies of them on Day 18 to 20 of pregnancy, revealed the presence of 16 fetuses. The morphological sex of these fetuses thus obtained coincided completely with the previous judgement based on the chromosomal sexing. 2) Production of chimeras of defined sex composition by aggregating two half-morulae of defined sex. Out of 147 pairs of half-morulae of two different strains (ICR and C3H/He), which were replaced in pairs into empty zona pellucidae, 107 (72.8%) were aggregated successfully and developed in vitro into full expanding blastocysts of typical form. Among the 107 aggregate blastocysts, 31 were sexed for both component embryos by chromosomal analysis on the co-twin half-embryos. When these 31 blastocysts were transferred, 11 living offspring including 4 chimeras were obtained. Transfer of 12 male-male and 5 female-female aggregate blastocysts resulted in 8 males and 1 female, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Fluctuations in peripheral serum testosterone levels within a day, with age and by sexual stimulation in male beagle dogs bred indoors.

Fluctuations in serum levels of testosterone (T) within a day, both with age and as a result of sexual stimulation, were examined in male beagle dogs. Eighty male dogs aged between 3 months and 16 years and bred in our laboratory were used under strictly controlled breeding conditions (temperature: 22 +/- 1 degree C, relative humidity: 55 +/- 5%, lighting time: 8:00 a.m.-8:00 p.m.). The level of T was measured by an RIA method. In order to examine the fluctuation in T level within a day, blood samples were obtained at 0:00, 6:00, 12:00 and 18:00 in each of five dogs aged 1.7 and 2.1 years. T levels fluctuated with a regular pattern that was lowest at 12:00, and increased to a peak at 18:00-6:00, thereafter decreasing until 12:00. In order to examine the change in T level with age, blood samples were obtained at 9:00, 12:00 and 16:00 from 70 dogs aged between 3 months and 16 years. The regular diurnal pattern of T level was usually seen, and the levels at 12:00 were always low and did not fluctuate at any age except for 6 months, and 13, 14 and 16 years. The T level at 9:00 increased to reach a peak at 4 years, whereas that at 16:00 did so at 2 years. T levels at 9:00 were significantly higher at 4-12 and 14 years than at 3 months, and were higher at 4 years than at 9 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1988

Forms of hepatic failure in patients with liver cirrhosis.

Four pathophysiological types of hepatic failure suffered by 59 patients with liver cirrhosis were defined: chronic-recurrent type (Group A), acute exacerbation of chronic (Group B), post-operative type (Group C) and terminal type (Group D). The etiological, clinical and prognostic characteristics of the four types of hepatic failure were examined. More patients of Group C were seen in recent years than former years, but the opposite trend was observed in Group D. Direct causes or precipitating factors of hepatic failure differed depending upon the type of hepatic failure. Mortality rates were higher than 80% in the acute types of hepatic failure (Groups B, C and D), but were 50% in the chronic type (Group A). The association of multiple organ failure was frequently observed in Groups C (67%) and D (39%). Lactulose, nonabsorbable antibiotics and branched-chain amino acid solutions were used in combination for the treatment of patients of Groups A and D, with rates of arousal from encephalopathy of 75% and 29%, respectively. Even though further therapeutic maneuvers for acute hepatic failure were employed in Groups B and C, only low arousal rates of 38% and 27%, respectively, were obtained.

Aged↗
PubMed1987

Expression of ABH and Lewis blood group antigens in combined hepatocellular-cholangiocarcinoma. Possible evidence for the hepatocellular origin of combined hepatocellular-cholangiocarcinoma.

Expression of ABH, Lewis, and sialyl Lea antigens was studied in five combined hepatocellular-cholangiocarcinomas. Formalin-fixed liver tissues were immunostained for those antigens using well-characterized monoclonal antibodies and an avidin-biotin-peroxidase complex (ABC) method. Results were compared with those obtained in normal liver tissues and cholangiocarcinomas, and also with the previous observations of the authors on hepatocellular carcinomas. Although not detected in normal parenchymal liver cells, A, H, Lewis, and sialyl Lea antigens were found in combined hepatocellular-cholangiocarcinoma cells. Incompatible A antigen also was detected in one blood type O patient. Distribution and intensity of the antigens were similar to those in hepatocellular carcinomas and different from those in cholangiocarcinomas. No preferential accumulation of blood-group antigens could be found in the area of cholangiocarcinoma-like differentiation of the combined hepatocellular-cholangiocarcinoma. The observations suggested that Regional morphological differentiation of the hepatocellular-cholangiocarcinoma might not be always associated with the change in the expression of the blood group antigens. Moreover, the expression was essentially the same between the hepatocellular-cholangiocarcinoma and the typical hepatocellular carcinoma. The hepatocellular-cholangiocarcinoma, therefore could be a variant of the hepatocellular carcinoma.

ABO Blood-Group System↗
PubMed1987

Modulation of stimulation-evoked release of newly formed acetylcholine from mouse hemidiaphragm preparation.

A radioisotope method has been developed for measuring the stimulation-evoked release of acetylcholine without the use of cholinesterase inhibitors from the mouse hemidiaphragm preparation which had been loaded with 3H-choline. Evidence has been obtained that 3H-choline was taken up by and released from both innervated and non-innervated mouse hemidiaphragm preparations. However, it was released in the form of 3H-acetylcholine in response to electrical field stimulation only from the innervated preparations. Long lasting (51 min) S1 stimulation of the preparations exhausted the radioactive acetylcholine stores to the extent that S2 did not evoke any release of 3H. These data suggest that when the labelled acetylcholine stores become exhausted, the labelled choline, still present in the tissue, cannot be released by electrical stimulation. Tetrodotoxin (1 mumol/l) administration and Ca withdrawal inhibited, 20-100 mumol/l 4-aminopyridine enhanced the release of 3H-acetylcholine in response to electrical stimulation. Activation of the presynaptic muscarinic receptors by the agonist oxotremorine (50 mumol/l) decreased the liberation of 3H-acetylcholine. The muscarinic antagonist atropine (1 mumol/l) abolished the inhibitory effect of oxotremorine and by itself increased the evoked release of the newly formed 3H-acetylcholine. Adenosine (50 mumol/l) reduced the evoked release of radioactivity. Theophylline (30 mumol/l) prevented the inhibitory effect of adenosine and itself enhanced the release. Xylazine (1 mumol/l), an alpha 2-adrenoceptor agonist did not affect the release. It is concluded that the stimulation-evoked release of 3H-acetylcholine from the mouse phrenic nerve hemidiaphragm preparation preloaded with 3H-choline is derived from the motor nerves. The release of acetylcholine is modulated by activation of presynaptic muscarinic and adenosine receptors.

4-Aminopyridine↗
PubMed1987

Pharmacokinetic studies of cimetidine in patients with liver disease.

The tolerability and metabolism of cimetidine administered for over 7 days were studied in 30 patients with liver diseases and 19 control subjects who had peptic ulcers. Cimetidine was well tolerated by these patients without any side effects. The cimetidine in the serum and urine was determined by high-performance liquid chromatography. The serum cimetidine levels and pharmacokinetic parameters of the patient group did not significantly differ from those of the control group after oral administration. Following intravenous administration, the half-life of cimetidine increased and cimetidine clearance decreased in the liver disease group. These differences seem to be totally explicable by the impaired renal function associated with the liver disease. Furthermore, accumulation of cimetidine in serum did not occur following continuous treatment with cimetidine in these patients. It was concluded that a reduction of cimetidine dosage is not necessary in patients with liver disease as far as their renal function is not disturbed, since the metabolism of cimetidine was not affected by the liver dysfunction itself.

Administration, Oral↗
PubMed1987

In vitro interferon producing activity of peripheral mononuclear cells in patients with chronic liver disease.

Interferon-gamma (IFN-gamma) was induced from a human peripheral mononuclear fraction by incubation with a streptococcal preparation stabilized with penicillin G (OK432). This IFN-gamma-producing activity was significantly reduced in patients with chronic hepatitis and hepatocellular carcinoma. In patients with liver cirrhosis it was also reduced but not significantly. Serum hepatitis B virus DNA and skin tests for the purified protein derivative of tuberculin, phytohemagglutinin-P and a polysaccharide fraction prepared from streptococcus pyogenes Su strain were determined to have no significant relation to this IFN-gamma-producing activity. Although the addition of interleukin 2 (IL-2) to the culture medium enhanced the IFN-gamma-producing activity, there was no difference in this enhancement between normal control and chronic hepatitis. Therefore reduction of the IFN-gamma-producing activity observed in chronic hepatitis seems to be caused by a decreased number of IFN-gamma-producing activity cells or hypofunction of these cells or both. Since HBeAg became negative in patients whose IFN-gamma-producing activity was increased by the administration of the immunopotentiator OK432 or IFN-beta, the IFN-producing system in the patients with B type hepatitis may contribute to the elimination of HBV. Adenine arabinoside suppressed IFN-gamma-producing activity both in vivo and in vitro.

Adult↗
PubMed1987

Ricinus communis agglutinin II-reactive glycoproteins from the ascites of patients with hepatocellular carcinoma and their use in enzyme-linked immunosorbent assay.

Ricinus communis agglutinin II-reactive glycoproteins from the ascites of patients with hepatocellular carcinoma were prepared using lectin affinity chromatography. Normal serum- and cirrhotic ascites-components were removed by columns with immobilized antibodies against them. Ricinus communis agglutinin II-reactive glycoproteins thus obtained were supposed to be hepatocellular carcinoma-associated and less than 0.1% of the protein in the starting material. Polyacrylamide gel electrophoresis of these glycoproteins revealed more than 10 major polypeptides with molecular weights ranging from 20K to 200K daltons. The rabbit antiserum raised against them reacted with at least three components of 45, 52 and 55K daltons. The serum level of this antibody-reactive glycoproteins was assessed by an enzyme-linked immunosorbent assay. It was elevated in 91% of cases of hepatocellular carcinoma, 70% of cases of other gastrointestinal carcinoma, 88% of cases of liver cirrhosis, 55% of cases of chronic hepatitis, and 25% of cases of acute hepatitis. The mean value of hepatocellular carcinoma was significantly greater than those of other groups. These results suggest that some of Ricinus communis agglutinin II-reactive glycoproteins in hepatocellular carcinoma patients may be cancer-associated glycoproteins and that their serum levels are increased in hepatocellular carcinoma patients.

Ascites↗
PubMed1987

Role of endogenous gastric mucosal prostaglandins in the formation of acute gastric mucosal lesions induced by aspirin, ethanol, HCl and CH3COOH.

The role of endogenous mucosal prostaglandins (PGs) in the production of acute gastric mucosal lesions (AGML) was examined in rats. Aspirin, ethanol or 0.6 N-HCl was given intragastrically and 20% acetic acid was injected into the gastric wall. Endogenous gastric mucosal PG (A + B), PGE and PGF were determined by radioimmunoassay. Their gastric contents were markedly reduced by aspirin administration (p less than 0.001). The level of gastric mucosal PGs still remained low (p less than 0.001) after the aspirin-induced AGML began to heal. Furthermore, rats with AGML induced by ethanol, HCl or acetic acid, showed no decrease in endogenous gastric mucosal PGs compared with the controls. These findings indicated that endogenous PGs are not necessary for either the induction or healing of experimental AGML.

Acetates↗
PubMed1987

Natural killer activity in patients with chronic hepatitis treated with OK432, interferon, adenine arabinoside and glycyrrhizin.

Natural killer (NK) activity in the peripheral blood of patients with chronic liver disease was measured using 51Cr labeled K562 cells as target cells. NK activity was elevated but not significantly in patients with chronic hepatitis compared with healthy controls and significantly lower in the patients with hepatocellular carcinoma. The activity decreased in the order of chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. Although the level of NK activity in patients with chronic hepatitis did not correlate with the level of alanine aminotransferase (ALT), it tended to be elevated in association with elevation of ALT in patients treated with OK432, interferon-beta, glycyrrhizin or adenine arabinoside. In chronic liver disease, phytohemagglutinin (PHA) skin test showed a positive correlation with NK activity. In all patients who were treated with the immunopotentiator, OK432, and whose HBeAg became negative, NK activity was elevated during the treatment. These results suggest that the NK activity in peripheral blood may be related to hepatocytic injury even if this is not the effector mechanism of the injury.

Adult↗
PubMed1987

Subgenomic studies on hepatitis B virus DNA integrated into the genome of hepatocellular carcinoma.

Integration of hepatitis B virus (HBV) DNA into the chromosomal DNA of hepatocellular carcinoma (HCC) tissue was studied by the Southern blot analysis using probes for subgenomic regions C, PreS, S and X. Eighteen Hind III-fragments prepared from DNA of the tumor regions of six patients with HCC, and hybridized with a full genomic HBV probe were analyzed. Lack of region S or PreS was concurrently accompanied by deletion of their 3'-end region of the HBV minus strand DNA. Region C was missing in 11 out of 18 fragments while regions X, S and PreS were deleted in 5/18, 3/18 and 5/18 respectively. Therefore, in some sequences integrated by subgenomic HBV DNA, the integration of replicative intermediate of the HBV minus strand DNA into the chromosomal DNA may take place and one of the viral integration sites seems to be in the region X.

Carcinoma, Hepatocellular↗
PubMed1987

Clinical evaluation of autoantibodies to liver cell membrane specific antigen, liver specific lipoprotein, and Tamm-Horsfall glycoprotein in autoimmune chronic active hepatitis.

An enzyme-linked immunosorbent assay was developed to detect circulating autoantibodies to three liver cell membrane surface antigens, i.e., liver cell membrane specific antigen (LCM), liver specific lipoprotein (LSP), and Tamm-Horsfall glycoprotein (THGP). In autoimmune chronic active hepatitis (autoimmune CAH), the positive rate and mean titer (normal range, less than 5.5 units) for anti-LCM were 100% and 13.5 units before corticosteroid treatment and 100% and 9.9 units during the treatment. The corresponding values for anti-LSP were 84% and 11.8 units, and 81% and 8.9 units, and those for anti-THGP were 84% and 12.3 units, and 81% and 7.9 units. In an autoimmune CAH patient, elevation of the plasma levels of autoantibodies during the treatment apparently preceded the elevation of alanine aminotransferase (ALT). However, the ALT elevation induced by transcatheter arterial embolization was not associated with the elevation of these autoantibodies in an autoimmune CAH patient with hepatocellular carcinoma. In primary biliary cirrhosis, drug-induced hepatitis, and non-hepatic immunological disorders, the production of the three autoantibodies did not directly correlate with liver cell damage. These findings suggest that the elevation of autoantibodies against LCM, LSP, and THGP can be a useful guide for the prednisolone treatment of autoimmune CAH.

Adult↗
PubMed1987

Immunohistochemical study of fibronectin, lysozyme, and alpha-fetoprotein (AFP) in human hepatocellular carcinoma.

We have immunohistochemically localized fibronectin, lysozyme and alpha-fetoprotein (AFP) in 21 human hepatocellular carcinoma (HCC) tissues obtained by surgical resection at both light and electron microscopic levels. Three distinct distribution patterns of fibronectin (sinusoidal, periacinar, and pericellular patterns) were observed. The sinusoidal and periacinar patterns were mainly observed in HCC of pseudoglandular or trabecular patterns and of Edmondson's grade I or II, whereas the pericellular pattern was observed in HCC of compact or trabecular patterns and of Edmondson's III grade, suggesting that the pericellular fibronectin was rather associated with undifferentiated HCC. Electron microscopic observation of the pericellular fibronectin showed fibronectin to be present in the dilated intercellular spaces where microvilli were moderately developed. We observed intracytoplasmic staining of fibronectin in 2 of the 21 HCC cases. By immunoelectron microscopy, fibronectin was observed in the endoplasmic reticulum (ER) of some HCC cells. In the 21 HCC cases, lysozyme-positive cancer cells were observed in 10 cases, and AFP in 6 cases. At the ultrastructural level, lysozyme was identified in the ER and the perinuclear spaces of HCC cells, suggesting that lysozyme was synthesized by these cells. Lysozyme-positive cases tended to be more frequently observed in cases with the pericellular pattern of fibronectin rather than those with sinusoidal or periacinar patterns.

Adult↗
PubMed1987

Effect of mono- and diaminopyridines on release of [3H]norepinephrine from isolated guinea-pig atrium.

Neurochemical evidence has been obtained that 4-aminopyridine, 3,4-diaminopyridine and 3,3-dimethyl-1-(4-amino-3-pyridyl)urea HBr (LF-14), concentration-dependently enhanced the stimulation-evoked release of [3H]norepinephrine ([3H]NE) from isolated guinea-pig atrium. The effects of aminopyridines, compounds known to inhibit potassium channels, were Ca0-dependent. High pressure liquid chromatography, combined with radiochemical detection, indicated that the increased stimulated release of radioactivity was due to [3H]NE. Since the aminopyridines studied also enhanced the release of [3H]NE from atrium treated with cocaine, a blocker of uptake1, it seems likely that the increased release of NE caused by the aminopyridines is due to the enhanced release of NE from sympathetic axon terminals and not to the inhibition of reuptake. It is probable that the sympathomimetic cardiac effects (positive inotropic and chronotropic effect) of aminopyridines observed in animal experiments is due to the increased release of NE, caused by these compounds.

4-Aminopyridine↗