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Biomedical subjects

H Nagashima

Publications and source records attributed to H Nagashima.

At least 199 records · Page 11Linked to original sources
PubMed1987

Direct evidence that pancuronium and gallamine enhance the release of norepinephrine from the atrial sympathetic nerve by inhibiting prejunctional muscarinic receptors.

The effect of different non-depolarizing muscle relaxants (gallamine, pancuronium, vecuronium, D-tubocurarine) on [3H]norepinephrine release in response to electrical stimulation was studied in isolated guinea-pig atrium. High pressure liquid chromatography combined with electrochemical and radiochemical detection revealed that the released radioactivity was mainly in the form of [3H]norepinephrine release. Oxotremorine, a pure muscarinic agonist, reduced the release of tritium. Gallamine and pancuronium, like atropine, prevented the inhibitory effect of oxotremorine. D-Tubocurarine and vecuronium had no such effect. These findings indicate that gallamine and pancuronium exert a presynaptic antimuscarinic, atropine-like effect, by inhibiting muscarinic receptors located on the axon terminals of sympathetic neurons thereby enhancing norepinephrine release. It is suggested that this phenomenon might play some role in tachycardia observed during surgical anaesthesia when gallamine or pancuronium have been administered.

Adrenergic Fibers↗
PubMed1987

Enhancement of low-dose N-2-fluorenylacetamide-induced hyperplastic liver nodules by pre-existing cirrhosis.

The potentiating effect of pre-existing cirrhosis on the formation of hyperplastic liver nodules and/or foci was investigated by feeding a low dose (0.008%) of 2-N-fluorenylacetamide (FAA) in a choline-deficient (CD) diet for 32 weeks to cirrhotic and non-cirrhotic rats. Liver cirrhosis was induced by feeding the rats a CD diet for the preceding 36 weeks. The number and area of gamma-glutamyltranspeptidase-positive hyperplastic liver nodules and/or foci were significantly larger in cirrhotic rats exposed to low-dose FAA than in non-cirrhotic rats similarly treated. Hyperplastic liver nodules and/or foci were not observed in rats continuously fed a CD diet alone for 68 weeks (control cirrhotic rats). The results suggest that cirrhotic liver might alter the metabolic response to FAA, even at low doses, and lead to enhanced induction of hyperplastic liver nodules and/or foci.

2-Acetylaminofluorene↗
PubMed1987

Neoexpression of ABH and Lewis blood group antigens in human hepatocellular carcinomas.

Expression of blood group ABH, Lewis, and sialylated-Lea antigens in human hepatocellular carcinomas and the adjacent nontumorous liver tissues was investigated with the use of seven monoclonal antibodies against these carbohydrate determinants. Chromatogram antibody-binding assay and solid-phase enzyme immunoassay of the upper-phase neutral glycolipids revealed the tumor-associated expression of blood group A-active glycolipids incompatible with blood-type status of the patients, a blood group A-active glycolipid with mobility on thin-layer chromatography between the known 6- and 8-sugar blood group A-active glycolipids in human erythrocytes, blood group H-active glycolipids, and blocked synthesis of Lea-active glycolipids with or without concomitant accumulation of Leb-active glycolipids. Immunohistochemical analysis of the fixed tissues with the use of an avidin-biotin-peroxidase complex method revealed blood group antigens in biliary epithelial cells but not in parenchymal liver cells. However, hepatocellular carcinoma cells in some cases expressed H and Leb antigens. Although only type 1 chain H antigen was detected in biliary epithelial cells, both type 1 and type 2 chain H antigens were found in hepatocellular carcinoma cells.

ABO Blood-Group System↗
PubMed1987

Follow-up study of 582 liver cirrhosis patients for 26 years in Japan.

A long-term follow-up study of liver cirrhosis (LC) was performed in 582 patients diagnosed by peritoneoscopy and liver biopsy in the 26 years from 1958 to 1984. The etiology of LC consisted of hepatitis B virus (HBV) in 21%, alcoholic in 39% and cryptogenic in 39%. Fifty-nine percent of patients had died. Causes of death were hepatocellular carcinoma (HCC 44%), liver failure (30%), rupture of esophageal varices (14%), gastrointestinal bleeding (4%) and non-liver-related causes (8%). HCC accounted for increasing percentages (68%) since 1980. In all groups classified by the etiology, the causes of death had the same order in incidence. The age of onset of LC increased by 10 years from 42 to 52 years old and the age of death by 15 years from 43 to 58 in the 26-year period. The cumulative survival rate improved over the period. The 50% survival year was 7.9 in total patients, and 7.0, 8.5 and 10.0 in the three periods 1958-64, 1965-74 and 1975-84, respectively. It was 9.5, 6.3 and 9.8 in HBV, alcoholic and cryptogenic, respectively. LC patients survived 40-44% of the life expectancy of the general population in Japan in all age groups. Cox's multiregression life-table method selected three important prognostic factors from 7 parameters: a poor prognosis with a history of heavy alcohol consumption and old age at onset, and a better prognosis with recent onset.

Actuarial Analysis↗
PubMed1987

The effect of cardiac sympathetic nerve stimulation on the right ventricle in canine heart.

The change in coronary hemodynamics during right or left cardiac sympathetic nerve stimulation was studied in anesthetized open chest dogs. No difference in the increasing rate of mean coronary blood flow between right coronary artery (RCA) and left anterior descending coronary artery (LAD) was observed. However the increasing rate of right ventricular systolic pressure X heart rate (RVSP X HR) was greater than that of left ventricle (LV). With phentolamine injection, cardiac sympathetic nerve stimulation showed similar changes as the controls. Beta-stimulation by isoproterenol infusion did not cause different effects on the increasing rate of coronary blood flow between RCA and LAD. These results showed that cardiac sympathetic nerve stimulation increased the double product of the right ventricle (RV) more than that of the LV and the increase was not affected by phentolamine. Moreover, cardiac sympathetic nerve stimulation, either the right or the left, caused the greater effects on the RV compared to the LV mainly through beta-adrenoceptors, and that the response of the RV to increase in oxygen demand was possibly, in part, different from that of the LV.

Animals↗
PubMed1987

Myocardial oxygen metabolism of the right ventricle with volume loading and hypoperfusion.

A comparison of blood flow and myocardial O2 consumption (MVO2) in the right and the left ventricles was made in dogs whose chests had been opened. The effect of volume loading by arterio-venous and arterio-left atrial shunts, and the effect of ventricular hypoperfusion by rapid removal of blood were examined in the presence and absence of the pericardium. Blood flow per unit myocardium was greater in the left anterior descending coronary artery (LAD) than in the right coronary artery (RCA), 75 +/- 4.3 vs. 46 +/- 2.8 (mean +/- SE) ml/min per 100g, respectively. Similarly, the myocardial O2 extraction ratio (EO2) was 59 +/- 2% in the left ventricle and 43 +/- 3% in the right ventricle (p less than 0.001). The MVO2 was greater for the left than for the right ventricle, 8.0 +/- 0.6 vs. 3.5 +/- 0.3 ml O2/min per 100g. Volume loading to both ventricles by arterio-venous (AV) shunt increased MVO2 of the right ventricle by augmented EO2 in addition to a rise in the coronary arterial blood flow. Decrease in aortic pressure by rapid removal of blood increased EO2 in both ventricles. The increments of EO2 were greater in the right ventricle than in the left ventricle, 54 vs. 31% (p less than 0.01). When the pericardium was closed with suture, right and left end-diastolic pressure rose, but EO2 and coronary blood flow of both ventricles did not change. We conclude that reserve capacity of myocardial O2 extraction was greater in the right ventricle than in the left ventricle.

Animals↗
PubMed1987

Nonsurgical collection of embryos in Shiba goats.

A method of nonsurgical embryo collection in the Shiba goat, a native Japanese miniature goat breeding nonseasonally, was developed. The apparatus used for flushing the uterus was made on the model of the two-way catheter for cows. Embryo collection was performed on days 5 to 7 in 37 females superovulated with PMSG and hCG and resulted in successful recovery of 69 embryos in 19 females (51.4%). The average number of embryos collected from each successful female was 3.6. The recovery rate of embryos calculated on the basis of the number of embryos recovered and corpora lutea observed by culdoscopy in 15 successful females was 89.5%. This nonsurgical method seem to be efficient enough for collecting morulae and blastocysts in Shiba goats.

Animals↗
PubMed1987

Application of 3 alpha-hydroxysteroid dehydrogenase column to the determination of bile acids fractionated by high-performance liquid chromatography: advantage of pretreating human bile acids with Seppak C18 and piperidinohydroxypropyl Sephadex LH-20.

The analysis of bile acids in human bile was tried by high-performance liquid chromatography (HPLC). Bile acids in human bile were first prefractionated into free, glycine- and taurine-conjugated bile acids using a Seppak C18 cartridge and a piperidinohydroxypropyl Sephadex LH-20 (PHP-LH-20) column. Each fraction was then processed through a HPLC system consisting of a Zorbax ODS column and a 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD) column. By these procedures the major 15 bile acids were clearly separated, and each bile acid of 10-125 ng was accurately analyzed. More than 400 times of analysis could be repeated on one 3 alpha-HSD column without loss of sensitivity. Thus the pretreatment through Seppak C18 and PHP-LH-20 made the HPLC analysis of human bile acids accurate and applicable to clinically obtained materials.

3-Hydroxysteroid Dehydrogenases↗
PubMed1987

Aspergillosis in acute hepatic failure.

Six (16.7%) out of 36 acute hepatic failure patients were associated with aspergillus infection mainly in the lungs (4 pneumonia and 2 fungus balls), which might be the cause of death in 4 cases. Preventive and therapeutic approaches following the early diagnosis have not been performed in all the cases. Fungal infection in hepatic failure should be considered to a greater extent to achieve a higher survival rate in this disease.

Acute Disease↗
PubMed1987

Treatment of hairy cell leukemia with alpha-interferon and splenectomy.

A typical case of hairy cell leukemia, very rare in Japan, is described. The biological characteristics of the disease and histological features of liver and spleen are also reported. Treatment with alpha-interferon and splenectomy was successfully performed, and the patient is now in good health.

Follow-Up Studies↗
PubMed1986

Electrochemical determination of histamine derivatized with o-phthalaldehyde and 2-mercaptoethanol.

High-performance liquid chromatography coupled with electrochemical detection was used to determine histamine following precolumn derivatization with o-phthalaldehyde (OPA) and 2-mercaptoethanol. The isoindole derivative which is obtained as reaction product was electrochemically active at a moderate potential (peak potential +0.4 V). Direct oxidation of histamine required a much higher potential (peak potential +1.05 V) and was of no practical use. No electrochemical signal was observed for the reaction product of histamine with OPA. Changing the pH of the mobile phase had little effect on the electrochemical response of the isoindole derivative of histamine, which was well separated from analogous derivatives of methylated histamines, mono- and polyamines and amino acids by isocratic elution from a reversed-phase column. An example of a practical application of the method to the estimation of histamine in rat brain is presented.

Animals↗
PubMed1986

Directional movement of F-actin in vitro.

By a fluorescence microscopic method for visualizing single filaments of F-actin in solutions, we have investigated movement of F-actin in a motility system in vitro. It was found that, when F-actin and myosin were mixed in the presence of Mg2+-ATP under appropriate conditions, individual F-actin filaments continued moving in different directions, but in parallel to their length, for a long period of time. The actin filaments did not reverse their direction of movement and had a distribution of speed with the maximum at about 5 micron per second (at 27 degrees C).

Actins↗