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Biomedical subjects

S Tamura

Publications and source records attributed to S Tamura.

At least 523 records · Page 29Linked to original sources
PubMed1990

Müllerian duct cyst: ultrasonographic and computed tomographic spectrum.

A Müllerian duct cyst (MDC) is the persistent remnant of the Müllerian duct. Reports of symptomatic cases are rare, signs and symptoms include perineal pain, dysuria, infertility, hematuria and genital inflammation. The prevalence of MDC has been previously reported as 4% of newborns and 1% in adult males. Herein we report six cases encountered in the past year. Our detection percentage was 1% and is compatible with the reported values. The imaging evaluation of symptomatic and asymptomatic patients with MDC is discussed as well as the apparent discrepancy between the number of previously reported cases and the reported prevalence.

Adolescent↗
PubMed1990

Inhibitory effect of a new alpha-glucosidase inhibitor on fatty liver in Zucker fatty rats.

The livers of Zucker fatty (fa/fa) and lean (Fa/-) rats treated with standard rat chow diet containing 0, 10 or 50 ppm alpha-glucosidase inhibitor (AO-128) for 10 weeks were studied morphologically and biochemically. Light microscopic examination of livers from untreated Zucker fatty rats showed severe steatosis. The triglyceride content in the livers from Zucker fatty rats was significantly higher than that from lean rats (73 +/- 9 micrograms/mg protein for Zucker fatty rats vs. 30 +/- 10 for lean rats, p less than 0.01). Administration of the inhibitor caused a marked decrease in the number and size of lipid droplets in the hepatocytes from Zucker fatty rats and a decrease in the triglyceride content in the liver (73 +/- 9 micrograms/mg protein for untreated, 54 +/- 16 for 10-ppm-treated and 48 +/- 23 for 50-ppm-treated rats, p less than 0.05). This is the first report showing an inhibitory effect of an alpha-glucosidase inhibitor on steatosis in Zucker fatty rats.

Animals↗
PubMed1990

Cross-protection against influenza B type virus infection by intranasal inoculation of the HA vaccines combined with cholera toxin B subunit.

The relationship between the antibody responses to various influenza B type virus HA vaccines and protection against live B virus infection was investigated in Balb/c mice which had been inoculated intranasally with a combination of the HA vaccines and B subunit of cholera toxin (CTB) 4 weeks previously. The inoculation of HA vaccine, prepared from B/Ibaraki/2/85 (B/Ibaraki), B/Nagasaki/1/87 (B/Nagasaki) or B/Aichi/5/88 (B/Aichi) viruses, combined with CTB induced high levels of both nasal IgA and serum HI antibodies to any of B/Ibaraki, B/Nagasaki and B/Aichi viral antigens. Simultaneous inoculation of each CTB-combined HA vaccine provided complete protection against B/Ibaraki virus infection which is demonstrated by both rapid clearance of pulmonary virus and complete survival. On the other hand, the inoculation of HA vaccine prepared from B/Yamagata/16/88 (B/Yamagata) virus together with CTB induced only a low level of nasal IgA antibodies, cross-reactive to B/Ibaraki, B/Nagasaki and B/Aichi viral antigens and protected only partially against B/Ibaraki virus challenge. The involvement of the B type virus-specific immunity in this protection was suggested by the absence of protection against B/Ibaraki virus infection in mice previously inoculated with both A/PR/8/34 (H1N1) virus HA vaccine and CTB. These results suggest that antibodies to various influenza B viruses are cross-reactive to each B type virus antigens and that cross-protection against B virus infection could be conferred depending on the degree of B type virus cross-reactive immunity including secretory IgA antibodies.

Animals↗
PubMed1990

Comparison of intranasal inoculation of influenza HA vaccine combined with cholera toxin B subunit with oral or parenteral vaccination.

The antibody responses to influenza virus A/PR/8/34 HA vaccine and protection against virus challenge in mice given the vaccine together with the B subunit of cholera toxin (CTB) intranasally were compared with those in mice given the vaccine with CTB perorally, intraperitoneally or subcutaneously. Intranasal vaccination induced remarkably higher levels of antiviral IgA antibodies in both respiratory washings and serum than did other routes of vaccination. The titres of antiviral IgG antibodies in respiratory washings and serum, and haemagglutination-inhibiting (HI) antibodies in serum, were similar after intranasal and parenteral vaccination. Oral vaccination, however, induced low levels of antiviral IgG antibodies but no detectable HI antibodies. Moreover, intranasal immunization elicited significantly higher titres of antiviral IgA antibodies in intestinal secretions in comparison with oral immunization. In contrast, parenteral immunization failed to induce these IgA antibodies. In virus challenge studies, a greater protective effect was seen after intranasal and intraperitoneal vaccination than after other routes of vaccination. These results suggest that intranasal inoculation of combined HA vaccine and CTB is superior to oral or parenteral inoculation in protecting mice. Furthermore, the intestinal antiviral IgA responses suggest that intranasal administration of CTB-combined vaccines could be effective not only against respiratory pathogens but also against enteropathogens.

Administration, Intranasal↗
PubMed1990

Functional role of respiratory tract haemagglutinin-specific IgA antibodies in protection against influenza.

Intranasal inoculation of haemagglutinin (HA) purified from influenza virus A/PR/8/34 (PR8, H1N1) together with cholera toxin B subunit, into Balb/c mice resulted in complete protection against PR8 infection in parallel with the induction of high levels of HA-specific IgA and IgG antibodies on the respiratory tract. The respiratory tract IgA and IgG were purified from nasal and lung washings of the immunized mice using affinity columns, and their HA-specific activities were measured by enzyme-linked immunosolvent, plaque neutralization and haemagglutination inhibition assays. The purified IgA and IgG had the following properties: (1) They were able to neutralize virus in vitro. (2) The purified IgA included major antibodies directed against PR8 virus and minor antibodies cross-reactive with A/Yamagata/120/86 (H1N1) or A/Fukuoka/C29/85 (H3N2) virus, while the purified IgG included major antibodies to the homotypic virus, minor antibodies to the H1N1 virus and only a trace amount of antibodies to the H3N2 virus. (3) When separated on a Sephacryl column, most of the IgA anti-HA activities occurred in the polymeric fractions of purified IgA, whereas the IgG anti-HA activities occurred in the monomeric fractions. (4) When passively administered to normal mouse respiratory tract before infection, the purified IgA protected against PR8 infection. These results suggest that HA-specific, polymeric IgA antibodies on the respiratory tract by themselves provide not only protection against the homotypic virus but also higher levels of heterotypic immunity than IgG.

Animals↗
PubMed1990

Monoclonal antibody to pseudouridine used to develop a radioimmunoassay.

Pseudouridine, a component of tRNA, was modified to yield the derivatives: succinyl, palmitoyl pseudouridine, and protein conjugates. These derivatives were used in preparation of monoclonal antibodies specifically directed to pseudouridine. MAbs from three hybridomas (OAL 881, 812 and 814) were established and shown to be directed to pseudouridine, uridine and uracil. OAL 881 was equally reactive with the three substrates, OAL 812 showed the same reactivity for pseudouridine and uracil, while OAL 814 showed a reactivity mainly for pseudouridine. MAb OAL 814 was used in a radioimmunoassay (RIA) system unique for pseudouridine. A good dose-response curve was observed in the range between 31.3 and 2000 nmol/ml. Intra- and inter-assay CV values were below 4.1% and 7.4% respectively, and good results were obtained from recovery of added material and dilution tests. The ratio of pseudouridine/creatinin in urine was significantly higher in patients with cancer than in normal subjects.

Antibodies, Monoclonal↗
PubMed1990

Enhancement of DTH response by cholera toxin B subunit inoculated intranasally together with influenza HA vaccine.

The effects of B subunit of cholera toxin (CTB) on delayed-type hypersensitivity (DTH) response to influenza vaccine derived from influenza virus A/PR/8/34 (PR-8, HlNl) virus were investigated in B10 mice that were immunized intranasally with both influenza vaccine and CTB. The result showed that intranasal inoculation of this combination augmented DTH response to influenza vaccine, which reached its peak 6 days after inoculation, and also induced accelerated DTH response upon a second inoculation of influenza vaccine alone 4 weeks later, that the cross-reactive DTH response to PR-8 vaccine was elicited by the injection of the different influenza A-type virus vaccine into the footpad of the vaccinated mice, but was not by influenza B-type virus vaccine, that the DTH-mediating T cells were detected selectively in the lungs of mice that received the nasal inoculation of the vaccine and CTB together, but that subcutaneous inoculation of this combination failed to induce DTH-mediating T cells in the lungs. These results, together with the previous papers (Tamura et al, Vaccine 7: 257-262; 314-320, 1989), suggest that CTB could augment both humoral and DTH responses against influenza vaccine in the respiratory mucosal tract.

Adjuvants, Immunologic↗
PubMed1990

Genetic transformation of Vibrio parahaemolyticus, Vibrio alginolyticus, and Vibrio cholerae non O-1 with plasmid DNA by electroporation.

An electroporation procedure for the plasmid-mediated transformation of the genus Vibrio was performed, as part of an effort to develop recombinant DNA techniques for genetic manipulation of the genus Vibrio. Vibrio parahaemolyticus, V. alginolyticus, and V. cholerae non O-1 (9 different strains) were transformed with 3 vector plasmids (pACYC184, pHSG398, and pBR325). The efficiency of transformation was highly dependent on three parameters: the concentration of plasmid DNA; the strength of the electric field; and the combination of plasmid DNA and recipient strain. The drug-resistance genes on the vector plasmid were expressed in the Vibrio strains.

DNA, Bacterial↗
PubMed1990

Particulate-associated protein phosphatases of rat hepatomas as compared with the enzymes of rat liver.

In the course of investigating the neoplastic alterations of protein phosphatases, the particulate fractions of rat liver and AH-13, a strain of rat ascites hepatoma, were chromatographed on DEAE-cellulose and assayed for protein phosphatase using glycogen synthase D and phosphorylase a as substrates. The synthase phosphatase activity of rapidly growing AH-13 was due almost entirely to a divalent cation-inhibited protein phosphatase, tentatively designated phosphatase N, the level of which was elevated remarkably in the hepatoma as compared with liver. Other hepatomas including primary hepatoma induced with 3'-methyl-4-dimethylaminoazobenzene also exhibited high levels of this phosphatase. Phosphatase N exhibited Mr = 49,000 (gel filtration) and has been partially purified with little alteration in properties. Partially purified phosphatase N was inhibited by divalent cations, rabbit skeletal muscle polypeptide inhibitor-2 and heparin, and released the catalytic subunit of type-1 protein phosphatase upon tryptic digestion. It is therefore apparent that phosphatase N is a type-1 protein phosphatase. There is some evidence to suggest that the high levels of phosphatase N in neoplastic cells are due primarily to enhanced synthesis of its non-catalytic (regulatory) subunit.

Adenosine Triphosphate↗
PubMed1990

Modulation of c-myc expression by transforming growth factor beta 1 in human hepatoma cell lines.

The effects of transforming growth factor beta 1 (TGF-beta 1) on cell proliferation of human hepatoma cell lines, PLC/PRF/5 and Mahlavu, were investigated under serum-free conditions. DNA synthesis was strongly inhibited in the PLC/PRF/5 cells by addition of TGF-beta 1 (0.5 to 4.0 ng/ml), but remained unchanged in the Mahlavu cells. Also the expression of c-myc mRNA was suppressed by the addition of TGF-beta 1 in the PLC/PRF/5 cells but not in the Mahlavu cells. These results indicate that TGF-beta 1 might regulate cell growth, in part, by modulating c-myc expression, although there is no direct proof that c-myc expression is really relevant to DNA synthesis mediated by TGF-beta 1.

Carcinoma, Hepatocellular↗
PubMed1990

Expression of transforming growth factor-beta 1 mRNA in human hepatocellular carcinoma.

We investigated the expression of transforming growth factor beta 1 (TGF-beta 1) mRNA in tumor tissues surgically removed from ten patients with hepatocellular carcinoma (HCC). All HCC tissues expressed TGF-beta 1 mRNA at different levels, indicating the presence of activated transcription of TGF-beta 1 gene in human HCC tissues in vivo. The level of TGF-beta 1 mRNA expression showed no relationship to main tumor size of plasma alpha-fetoprotein level. Some HCC tissues presenting a relatively low grade of histological differentiation showed the highest levels of TGF-beta 1 mRNA expression.

Aged↗
PubMed1990

Characterization of protein phosphatases associated with the particulate fraction from rat liver.

Protein phosphatases associated with the particulate fraction from rat liver were studied by chromatographing the fraction on a DEAE-cellulose column and assaying the eluate with phosphorylase alpha and glycogen synthase D as substrates. Phosphorylase phosphatase activity emerged as two peaks, termed P-1 and P-2 in order of elution, both of which were inhibited by Mn2+ and Mg2+. P-1 and P-2 were Mr = 50,000 and 32,000 proteins, respectively, and when treated with trypsin, P-1 converted to a form indistinguishable from P-2, to which protein phosphatase inhibitor-2 was a potent inhibitor. Thus P-2 appears to be the catalytic subunit of type-1 protein phosphatase even though it has been degrated proteolytically as evidenced by its relatively low Mr. The elution profile of glycogen synthase phosphatase activity was entirely different. The activity obtained with 5 mM Mn2+ resolved into three peaks, the second-migrating M-2 being the largest. M-2 is an Mr = 70,000 protein; but an attempt to purify it has been unsuccessful giving a product of Mr = 40,000 and closely similar to the type-1 catalytic subunit in properties including inhibition by inhibitor-2. These results suggest that phosphatases P-1 and M-2 have a common catalytic subunit (type-1), which is bound to different "regulatory" subunits. M-2 distributes in glycogen particles and microsomes evenly while P-1 is almost exclusively in microsomes.

Animals↗
PubMed1990

[Study on serotonin metabolism in toxemia of pregnancy].

To evaluate the serotonin (5-HT) metabolism in toxemia of pregnancy, plasma free 5-HT, 5-hydroxyindoleacetic acid (5-HIAA), tryptophan and platelet 5-HT content were determined by high performance liquid chromatography (HPLC) with electrochemical detection. The mean plasma free 5-HT concentrations in the severe preeclamptic group (S) and the mild preeclamptic group (M) were significantly higher than those in the normal group (N). A significant correlation was found between plasma free 5-HT values and Gestosis Index scores. However, there was no significant difference between plasma 5-HIAA level and platelet 5-HT content in the preeclamptic groups and the N. The mean plasma beta-thromboglobulin (beta-TG) concentrations in the preeclamptic groups were significantly higher than those in the N. The mean platelet counts in the S were significantly lower than those in the N. The mean plasma 5-HIAA/5-HT ratio in the preeclamptic groups were significantly lower than those in the N. In conclusion, it is suggested that the higher plasma free 5-HT level in the toxemia of pregnancy seems to be attributed to the excess release of 5-HT from platelets in addition to the lower monoamine oxidase activity.

Blood Platelets↗
PubMed1990

[Serotonin metabolism in normal pregnant women and fetus].

To evaluate serotonin (5-HT) metabolism in normal pregnant women and their fetuses, plasma free 5-HT, 5-hydroxyindoleacetic acid (5-HIAA). Tryptophan (TRP) and platelet free 5-HT content were determined by HPLC with electrochemical detection. Plasma free 5-HT and TRP concentrations and platelet 5-HT content in pregnant women did not change during pregnancy. In contrast, plasma free 5-HIAA increased after 30 weeks of gestation and reached its peak at 37 weeks. 5-HT, 5-HIAA and TRP concentrations in umbilical cord plasma were significantly higher than in maternal plasma. However, platelet 5-HT content in the fetus was significantly lower than in the mother. No significant correlation was found between 5-HT concentrations in maternal and cord plasma. However, a significant correlation was found between 5-HIAA, concentrations in maternal and cord plasma. The total 5-HT/TRP ratio in cord blood was significantly lower than in the maternal vein. The 5-HIAA/5-HT ratio in cord plasma was markedly higher than in maternal plasma. In conclusion, we demonstrated the patterns of plasma free 5-HT, 5-HIAA, TRP and platelet 5-HT concentrations in normal pregnant women and their fetuses. Furthermore, rapid 5-HT metabolism in the fetus was suggested.

Female↗
PubMed1990

[A surgical case of atrial septal aneurysm associated with rheumatic mitral and tricuspid disease and coronary-pulmonary artery fistula].

A case of atrial septal aneurysm associated with combined valvular disease and coronary-pulmonary fistula (C-PA fistula) was presented. The patient successfully underwent mitral valve replacement, excision and closure of the aneurysm, tricuspid annuloplasty and closure of C-PA fistula. Atrial septal aneurysm is a rare anomaly and its natural course is thought to be generally good without significant clinical symptoms. However, complications such as cerebral and pulmonary embolism, or occlusion of the atrioventricular vales by the prolapsed aneurysm were reported to occur in small number of cases. In this case, diagnosis of the aneurysm was made by 2-D and Doppler echocardiography and further confirmed by cineangiography. Routine echocardiographic examinations will serve as useful noninvasive method for detection and follow up study of this anomaly.

Arterio-Arterial Fistula↗