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Biomedical subjects

S Tani

Publications and source records attributed to S Tani.

At least 127 records · Page 7Linked to original sources
PubMed1989

Induced circular dichroism in nucleic acid-acridine derivative complexes.

Visible absorption and circular dichroism (CD) spectra have been measured for complexes formed between nucleic acids (calf thymus DNA, poly(rA).poly(rU) and poly(rI).poly(rC)) and 9-aminoacridines (quinacrine, acranil and 9-amino-6-chloro-2-methoxy acridine). With poly(rA).poly(rU), a new absorption band was observed at longer wavelengths. The nucleic acid-drug complexes showed considerable different induced CD spectra. Analysis of these CD spectra suggests that the cationic side chains of quinacrine and acranil play an important role on the binding properties to DNA and poly(rA).poly(rU).

Acridines↗
PubMed1988

Molecular orbital study on the metabolic pathway through the diol epoxide form of carcinogenic benzene in comparison with benzo[a]pyrene.

The stabilization energy for the hydronium-ion-catalyzed hydrolysis of benzene diol epoxide (BDE) in the configuration of anti- or syn-form has been estimated by using the semi-empirical molecular orbital calculations with the CNDO/2 method. The values for the formation of carbonium ion from BDE are compared with those from benzo[a]pyrene, and it is suggested that the anti-form BDE belongs to a relatively strong reactive group with benzo[a]pyrene and benz[a]anthracene. The reactivity of BDE to the cation is completely different from that of polycyclic aromatic hydrocarbon diol epoxides (PAHDEs) from the viewpoint of the electronic structure; the cation from the anti-form BDE has a three center-four electron bond, whereas cations from PAHDEs do not have such a bond and the aromaticity still remains.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed1988

Pancreatic endocrine function in cirrhotic rats.

Pancreatic endocrine function in liver cirrhosis was examined in rats both in vivo and in vitro. Experimental liver cirrhosis was induced by subcutaneous injections of 50% carbon tetrachloride in a dose of 2 mL/kg body weight twice a week for 16 weeks. Control rats received a similar dose of olive oil during the same period. In cirrhotic rats, immunoreactive insulin contents in the pancreas were significantly lower, whereas immunoreactive glucagon contents were about threefold higher than those of control rats. In the first part of this study, insulin and glucagon concentrations in both jugular and portal venous blood at basal conditions and after oral glucose loading were simultaneously determined in vivo. Peripheral insulin levels, both before and after glucose loading, were higher, whereas portal insulin concentrations were lower in cirrhotic rats than in the control rats. In contrast, glucagon levels in both the peripheral and portal veins were significantly higher in cirrhotic rats than in control rats. In the second part, isolated perfused pancreata were prepared from cirrhotic and control rats to further characterize the endocrine function of cirrhotic rat pancreas. Insulin secretion in response to 16.7 mmol/L glucose and 100 pmol/L cholecystokinin-octapeptide both were 40% lower in cirrhotic rats than in controls. In contrast, there was no significant difference in arginine-stimulated insulin release between the two groups. However, glucagon secretion in response to 20 mmol/L arginine was 40% higher in cirrhotic rats. If sensitivity is defined as the hormone release proportional to the pancreatic contents, then A and B cells in the cirrhotic rats had normal sensitivity to both glucose and cholecystokinin-octapeptide.(ABSTRACT TRUNCATED AT 250 WORDS)

Ammonia↗
PubMed1988

An epidemiologic study of effects of alcohol in the liver in hepatitis B surface antigen carriers.

A total of 932 hepatitis B surface antigen (HBsAg) carriers and 1,704 HBsAg-negative inhabitants of the Yaeyama District of Okinawa, Japan, over age 20 years were investigated in 1982-1985 in order to elucidate whether an interaction between habitual alcohol intake and hepatitis B virus infection is capable of producing liver disease. All of the subjects were tested for biochemical liver functions and asked about their habitual intake of alcohol. HBsAg carriers were tested for hepatitis B e antigen (HBeAg) and antibody to HBeAg. Subjects were ranked into three categories by alcohol consumption: nondrinkers, light drinkers (1-59 g/day), and heavy drinkers (greater than or equal to 60 g/day). The prevalence of liver abnormalities in HBsAg carriers increased with alcohol consumption. The prevalence differed significantly between nondrinkers and light drinkers in HBsAg carriers (p less than 0.001), but not in HBsAg-negative inhabitants. Prevalence also differed significantly between nondrinkers and heavy drinkers irrespective of HBsAg positivity (p less than 0.001). The highest prevalence of liver abnormalities was observed in HBeAg-positive heavy drinkers (53.8%). In conclusion, this study confirms that alcohol consumption intensifies the development of liver disease caused by hepatitis B virus. Therefore, the authors see a need to educate HBsAg carriers about the risks of consuming alcohol.

Adult↗
PubMed1988

Prevalence of gallstone disease in a general population of Okinawa, Japan.

A total of 2,584 healthy residents in the Yaeyama District of Okinawa, Japan, were investigated in 1984 to determine the prevalence of gallstone disease and its associated factors. Diagnosis of gallstone disease was assessed by real-time ultrasonography. For participants over 20 years of age, obesity index and serum levels of total cholesterol and triglycerides were measured. Overall prevalence of gallstone disease was 3.2%. Prevalence increased with age from 0% under 19 years of age to 11.4% over 70 years of age and was higher in females (4.0%) than in males (2.5%). The results of the logistic regression analysis indicated that age and fatty liver were significant predictors of gallstone disease. The results of the automatic interaction detector analysis indicated that age and fatty liver were strong factors associated with gallstone disease and that prevalence was highest in females over age 50 with fatty liver.

Adolescent↗
PubMed1988

Characteristic distribution of cathepsin E which immunologically cross-reacts with the 86-kDa acid proteinase from rat gastric mucosa.

The antiserum raised against the high-molecular-weight acid proteinase from rat gastric mucosa, termed 86-kDa acid proteinase, has been shown to recognize rat cathepsin E, but not cathepsin D (Muto, N. et al. (1987) J. Biochem. 101, 1069-1075). Using this specific antiserum, characteristic distribution of cathepsin E in rats was demonstrated. The enzyme was detected in a limited number of tissues, such as stomach, thymus, spleen, bladder, and erythrocyte membranes. Among them, the highest activity was observed in the stomach. In contrast, cathepsin D immunoreactive with the antiserum specific to rat gastric cathepsin D was demonstrated in all the tissues examined. Cathepsin E-type enzymes partially purified from these five tissues were precipitated in the same manner by the specific antiserum, and they had the same molecular weight, electrophoretic mobility, and resistance against denaturation by 4 M urea. These results indicate that they could be exactly classified as cathepsin E. This type of enzyme was also detectable in mice and guinea pigs, but they showed relatively weak immunoreactivities with the antiserum. Thus, it is concluded that the distribution of cathepsin E is intrinsically different from ordinary cathepsin D, suggesting that it has a different physiological role from cathepsin D.

Animals↗
PubMed1988

Effects of hydrocortisone on glucose- and cholecystokinin-induced insulin release from the isolated perfused rat pancreas.

The acute and chronic effects of hydrocortisone on insulin secretion were examined in the isolated perfused rat pancreas. In the first part of this study, the chronic effects of hydrocortisone on insulin release were examined using isolated perfused pancreas prepared from rats that had been given subcutaneous injections of hydrocortisone at doses of 1.25, 2.5, 5.0, and 10.0 mg/kg body weight once daily for 7 days. Hydrocortisone treatment led to a dose-dependent increase in insulin secretion in response to 8.3 mM glucose. The insulin response to 100 pM cholecystokinin (CCK-8) was also significantly higher in the hydrocortisone-treated rats than in the control group. However, the increment of insulin level over the value before CCK-8 addition in rats treated with hydrocortisone was not significantly different from that in the control rats. In the second part, the acute effects of hydrocortisone on insulin release were studied. Hydrocortisone (17-hydroxycorticosterone) at a concentration of 100 microM caused significant inhibition of the stimulatory effect of CCK-8 on insulin secretion. The inhibition started within 1 min of the beginning of hydrocortisone administration and ceased immediately after the termination of its infusion. We have demonstrated in this study a dual effect of hydrocortisone on insulin release: first, the potentiation of the insulin secretion stimulated by glucose but not by CCK-8 and, second, the inhibition of CCK-8-stimulated insulin secretion.

Animals↗
PubMed1988

The protective effect of the trypsin inhibitor urinastatin on cerulein-induced acute pancreatitis in rats.

We examined the protective effects of the trypsin inhibitor, urinastatin, extracted from human urine in experimental acute pancreatitis in conscious rats. Acute pancreatitis was induced by four subcutaneous injections of 20 micrograms/kg body weight of cerulein at hourly intervals. Urinastatin at a dose of 50,000 U/kg body weight/6.5 h was given by continuous i.v. infusion beginning 0.5 h before the first cerulein injection and continuing until 3 h after the last one, for a total of 6.5 h. Urinastatin significantly reduced serum levels of amylase, lipase, and anionic trypsin(ogen) but did not affect pancreatic wet weight or protein or enzyme content. Urinastatin also significantly reduced the degree of acinar cell vacuolization, interstitial edema, and cellular infiltration. These results suggest that urinastatin does not block the induction of acute pancreatitis by cerulein but does substantially reduce its severity.

Acute Disease↗
PubMed1988

Seroepidemiologic study of adult T-cell leukemia virus (ATLV) and hepatitis B virus infection in Okinawa, Japan.

A total of 2,283 serum samples were collected from healthy subjects in three islands of the Yaeyama district of Okinawa, Japan. These sera were tested for the presence of hepatitis B surface antigen (HBsAg), for antibody to hepatitis B core antigen (anti-HBc), and for antibody to adult T-cell leukemia-associated antigen (anti-ATLA). Correlation between hepatitis B virus infection and adult T-cell leukemia virus (ATLV) infection was determined by using the prevalence rates for three virus markers. Overall prevalence of HBsAg, anti-HBc and anti-ATLA was 6.5%, 57.4%, and 17.9%, respectively. Age-specific prevalence of anti-HBc and anti-ATLA increased with age, but that of HBsAg did not. Sex-specific prevalence of HBsAg was significantly higher in males than in females, but that of anti-ATLA was significantly higher in females than in males. Statistical analysis revealed that prevalence of anti-ATLA was significantly higher in HBsAg-positive persons and HBsAg-negative/anti-HBc-positive persons than in those negative for HBsAg and anti-HBc. These data suggest that hepatitis B virus-infected persons have a significantly higher chance of adult T-cell leukemia virus infection than those without hepatitis B virus infection in the area studied.

Adolescent↗
PubMed1988

Induction of secondary IgE antibody response in rats immunized with X-irradiated metacercariae of Paragonimus ohirai.

Rats reinfected with Paragonimus ohirai (P.o.) elicited little secondary IgE response to adult P.o. antigen. In contrast, rats immunized with X-irradiated (2-10 krad) metacercariae elicited not only a marked primary IgE response comparable to that in normally infected rats, but also a marked secondary IgE response after challenge infection. Rats immunized with 2 krad X-irradiated metacercariae yielded a higher secondary IgE response than with 5 or 10 krad irradiated ones, and elicited a secondary response lasting at least 1 year. An IgE response to antigen of newly excysted juvenile parasites (NEJ) was clearly different from the IgE response to adult P.o. antigen. The former IgE response was weak after infection or immunization, but after challenge infection a marked secondary response occurred at a level similar to the IgE response to adult P.o. antigen. The secondary IgE responses to adult P.o. and NEJ antigens were also elicited by reinoculation with X-irradiated metacercariae. Cross-absorption experiments confirmed that there were adult type and NEJ type allergens.

Animals↗
PubMed1988

Prevalence of fatty liver in a general population of Okinawa, Japan.

A total of 2,574 residents in Yaeyama District of Okinawa, Japan, were investigated using real time ultrasonography to determine the real prevalence of fatty liver in the general population and to define its associated factors. Overall prevalence of fatty liver was 14.0%. Prevalence of fatty liver in persons under 19 years old was only 1.2%, and increased with age to a maximum in persons 40-49 years of age and then decreased. For persons over 20 years old, obesity index and serum levels of triglyceride and total cholesterol were measured, and alcohol consumption was asked. Prevalence of fatty liver was significantly higher in drinkers than non-drinkers (p less than 0.01), and increased with alcohol consumption. Furthermore, in persons not suffering from obesity prevalence of fatty liver was significantly higher in drinkers than in non-drinkers (p less than 0.001). The results of logistic regression analysis indicated that obesity and elevated serum triglyceride level in both sexes, and alcohol in males were significant predictors of fatty liver. In conclusion, prevalence of fatty liver increased with age to a maximum in persons 40-49 years of age and overall was 14.0%. Obesity was the strongest associated factor in both sexes and in males alcohol was also a strong factor.

Age Factors↗
PubMed1988

Secretin-induced exocrine secretion in perfused pancreas isolated from diabetic rats.

Exocrine secretory function in response to 10 pM to 10 nM synthetic secretin was evaluated in perfused pancreas isolated from control, streptozocin-induced diabetic (STZ-D), alloxan-induced diabetic (ALX-D), and insulin-treated STZ-D rats. In STZ-D rats, the basal rate of pancreatic juice flow was significantly increased (10.3 +/- 1.0 microliters/20 min) compared with control rats (4.4 +/- 0.2 microliters/20 min). The basal rate of amylase output as well as pancreatic amylase content were significantly decreased to less than 5% of control values. The basal rates of protein and trypsinogen outputs were similar in both groups. In both control and diabetic rats, secretin caused a dose-dependent increase in exocrine secretion. Secretin (10 pM to 10 nM) induced 1.1- to 11.7-fold increases in exocrine secretion in STZ-D rats. These increases were significantly lower than the 2.1- to 20.8-fold increases in control rats. Furthermore, there was no significant increase in exocrine secretion from STZ-D rats in response to 10 pM secretin, although this concentration of secretin caused a significant increase in control rats. Secretin-induced exocrine secretion in ALX-D rats was similar to that in STZ-D rats. In insulin-treated STZ-D rats, the basal rates of pancreatic secretion were not significantly different from those of control rats. These results suggest that insulin resistance in this patient was due to a circulating factor of low molecular weight that uncoupled insulin stimulation of glucose transport from receptor binding and phosphorylation. The factor appears to increase the binding activity of the alpha-subunit of the insulin receptor without affecting the kinase activity of the beta-subunit.

Amylases↗
PubMed1987

Immunochemical similarity between a gastric mucosa non-pepsin acid proteinase and neutrophil cathepsin E of the rat.

Antiserum against a rat gastric mucosa non-pepsin acid proteinase precipitates rat neutrophil cathepsin E, with a precipitation curve essentially similar to that of the gastric enzyme. Taken together that the antiserum precipitates a cathepsin E-like acid proteinase from rat spleen (Muto, N., Yamamoto, M. and Tani, S. (1987) J. Biochem. (Tokyo) in press), the data indicate that the non-cathepsin D acid proteinases in rat neutrophils, gastric mucosa and spleen are immunochemically closely related. In contrast with the earlier data, cathepsin E from rabbit neutrophils exhibited a maximal activity at around pH 3.0-3.2 and preferred hemoglobin to albumin as substrate, which supports that the non-cathepsin D acid proteinases in the rat tissues are relevantly classified as cathepsin E.

Animals↗
PubMed1987

Inhibitory effects of pirenzepine on cholecystokinin and secretin stimulation on exocrine and endocrine rat pancreas.

Effects of pirenzepine, a newly developed anticholinergic drug, on exocrine and endocrine pancreatic functions stimulated by cholecystokinin octapeptide and secretin were studied in both isolated pancreatic acini and the isolated perfused pancreas of rats. In the isolated acini, pirenzepine did not have any significant effect on cholecystokinin-induced amylase release but caused an inhibition of amylase secretion initiated by secretin and shifted the dose-response curve for amylase secretion to the right. In the isolated perfused pancreas stimulated with 100 pM cholecystokinin octapeptide, addition of 10 microM pirenzepine before as well as after 20 min of perfusion significantly inhibited pancreatic juice flow but not enzyme output. In contrast, pirenzepine caused an inhibition of secretin-stimulated enzyme secretion, but not pancreatic juice flow. The stimulatory effect of both cholecystokinin octapeptide and secretin on insulin secretion was also inhibited by pirenzepine. The present data indicate that pirenzepine may have an influence on pancreatic exocrine and endocrine function by inhibiting endogenous cholinergic activity of the pancreas when a large dose is given.

Amylases↗
PubMed1987

A seroepidemiologic study of hepatitis A virus infections: statistical analysis of two independent cross-sectional surveys in Okinawa, Japan.

To investigate the endemic situation of hepatitis A virus infection in the past in Okinawa, Japan, the authors analyzed two sets of cross-sectional data on age-specific prevalence of antibody to hepatitis A virus (anti-HAV) obtained in 1968-1973 and 1980-1981 by fitting a catalytic model. For these two sets of data, the asymptotic level of infectious force of hepatitis A virus, namely lambda infinity, was estimated as 0.121 and 0.149, the maximum slope of the time-dependent force of hepatitis A infection, namely alpha, was 0.566 and 0.529, and the year when the force of hepatitis A infection had decreased to the half of lambda infinity, namely beta, was 1966 and 1964, respectively. In the test for the equality of parameters for the two applications, the difference was not significant. Furthermore, the fitness of the catalytic model to the data on anti-HAV prevalence was good. The results of the analysis by fitting the catalytic model show that hepatitis A infection had been highly endemic, that is, 136 infections per 1,000 persons per year in the area studied before 1955, and it decreased rapidly during the 1960s. Since 1975, hepatitis A has been a rare disease (infection is almost zero per 1,000 persons per year) in Okinawa, Japan.

Adult↗