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Biomedical subjects

T Arima

Publications and source records attributed to T Arima.

At least 271 records · Page 15Linked to original sources

Synthesis of prostaglandins, TXA2 and PGI2, during one lung anesthesia.

This study is to determine histamine, serotonin, TXA2 and PGI2 to be the cause of Hypoxic Pulmonary Vasoconstriction (HPV) at the same time of one lung ventilation and thoracotomy. Five patients who were to undergo upper-lobe resection of the right lung, were included in this study. All patients underwent same premedication and anesthetic method. Endotracheal intubation was done with a Univent tracheal tube. Gas analysis and determinations of the substances were done at six times in total. Respiratory Index (RI) began to increase immediately after the start of one lung ventilation. Post-thoracotomy RI further increased. After closing of the thorax, RI returned to the control values. Serotonin and histamine showed no change in any case throughout the experiment. TXB2 began to increase along with the start of one lung ventilation. The 15-min value was 167.2 +/- 85.8 pg/ml and 30-min value was 345.6 +/- 261.2 pg/ml, showing significant increase. The values of 6-keto PGF1 alpha were 22.6 +/- 2.9 pg/ml (15-min value), 89.6 +/- 52.3 pg/ml (30-min value), 290.8 +/- 120.1 pg/ml (post opening value) and 84.4 +/- 21.3 pg/ml (post-closing value). In our study, we concluded that neither serotonin nor histamine was the direct factor of HPV. TXA2 was the direct chemical mediator of HPV and PGI2 showed a negative feedback to the pulmonary vasoconstriction.

6-Ketoprostaglandin F1 alpha↗

Three-dimensional visualizations of the inner ear hair cell of the guinea pig. A rapid-freeze, deep-etch study of filamentous and membranous organelles.

The fine structure of the filamentous and membranous organelles in the stereocilia and in the cuticular plate of sensory hair cells from the guinea pig was examined using a rapid-freeze, deep-etch method. In fixed and unfixed tissue the outer surface of the plasma membrane of the stereocilia had numerous surface protrusions of various sizes and shapes, while the protoplasmic fractured face of the membrane had rather sparse intramembrane particles. Many tiny cross links were present between the adjacent actin filaments and between actin filaments and the plasma membrane of the stereocilia. Numerous fibrils radiating from the hair rootlet were attached to the peripheral actin filaments in the cuticular plate. The radiating fibrils differed from the tiny cross links which interconnected the adjacent, randomly-oriented actin filaments in the cuticular plate. These complex structures consisting of actin filaments in the hair rootlets, radiating fibrils, and peripheral actin filaments may play an important role in regulating stereociliary bending.

Actin Cytoskeleton↗

Influences of pertussis toxin, guanine nucleotides and forskolin on adenylate cyclase in striatal membranes of infant, adult and senescent rats.

To identify age-related changes in the dopamine (DA) receptors-GTP-binding protein-adenylate cyclase system, the following experiments were performed at 7 days (infant), 70 days (adult) and 2 years (senescent) in striatal membranes of rats: (1) effects of GTP in the presence and absence of pertussis toxin (islet-activating protein, IAP) on adenylate cyclase in the presence of forskolin alone, (2) the same in the presence of forskolin plus DA and (3) the corresponding effect of guanyl-5'-yl-beta, alpha-imido-diphosphate (GppNHp). GTP caused biphasic effects: the activation at 1 microM and the inhibition at 100 microM on forskolin-stimulated cyclase activity at 70 days. The inhibition was suppressed with IAP pretreatment. In infant membranes, 100 microM GTP inhibited the activity in the absence and presence of 100 microM DA and IAP induced a reversal from the inhibition to the stimulation only in the presence of DA. In senescent animals, neither GTP nor IAP affected the activity. GppNHp at 1, 10 and 100 microM only activated and did not inhibit forskolin-stimulated cyclase at each stage. GppNHp-caused stimulation was no more affected by IAP. IAP ADP-ribosylated 41,000 dalton proteins at each stage and the specific activity of ADP-ribosylation was not changed during development and aging. It is suggested that inhibitory GTP-binding protein (Gi) with molecular size of 41,000 dalton is involved in DA receptor-adenylate cyclase system whose function is low at infant stage and markedly decreased at senescent stage in rat striatal membranes.

Adenylate Cyclase Toxin↗

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↗

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↗

Influence of pertussis toxin on the effects of guanine nucleotide on adenylate cyclase in rat striatal membranes.

The influence of pertussis toxin on the effects of guanine nucleotide on adenylate cyclase activity were investigated in rat striatal membranes. GTP promoted and inhibited the activity at 1 and 100 microM, respectively. The inhibitory effects of GTP were abolished by pretreatment of the membranes with pertussis toxin. GppNHp (guanyl-5'-y1-beta,gamma-imidodiphosphate) exerted only stimulatory effects and pertussis toxin did not affect the effects of GppNHp. GDP at 10 and 100 microM caused significant inhibition which was completely suppressed by pertussis toxin. It is suggested that guanine nucleotide regulates the affinity of as in stimulatory GTP-binding regulatory protein to either beta gamma or catalytic units of adenylate cyclase in a flip-flop manner. Inhibitory GTP-binding regulatory protein seems to play a regulatory role in inhibiting alpha s activity supplying the beta gamma heterodimer.

Adenylate Cyclase Toxin↗

Hepatitis B virus DNA in human hepatocellular carcinoma: is the integration of hepatitis B virus DNA really carcinogenic?

Hepatitis B virus-specific DNA sequences (HBVDNA) in the liver were examined in 19 patients with hepatocellular carcinoma (HCC), 5 patients with liver cirrhosis (LC) and without HCC, 3 patients with chronic hepatitis (CH), 2 patients with metastatic liver cancer (MLC), 1 patient with primary biliary cirrhosis (PBC) and 4 patients with normal liver (NL) by the Southern blot hybridization procedure. Integration of HBVDNA was found in all 4 HCC patients with serum HBsAg, of whom one patient had HBVDNA only in the non-tumor (cirrhotic) region. Integration of HBVDNA was also detected in 4 of 8 HCC patients without serum HBsAg but with serum HBV-related antibodies, and in 2 HBsAg-positive patients of 5 LC patients. All 3 HBsAg-positive CH patients had only extrachromosomal HBVDNA. No HBVDNA was detected in the other 21 patients. Although integration of HBVDNA was observed in HBsAg-positive HCC patients with a higher frequency, integrated HBVDNA could also be detected in non-tumor regions of HCC patients and cirrhotic livers without HCC. It was concluded from these observations that integration of HBVDNA was frequently associated with HCC but might not have a direct causal effect on hepatocarcinogenesis even in HBV carriers.

Adult↗

Purification and characterization of a liver cell membrane specific antigen.

Antibodies against human liver cell membranes were raised in rabbits by immunizing 105,000 g precipitate of normal human liver homogenates (insoluble fraction). After absorption with non-liver antigens such as human spleen, kidney, lung homogenates and serum, the anti-liver cell membrane specific antigen (LCM) IgG fraction was prepared. The antibody reacted with both 105,000 g supernatant of the liver homogenate (soluble fraction) and Triton X-100 extract of the insoluble fraction, and with the surface of Chang liver cells. Using affinity columns to conjugate this antibody and other antibodies against non-liver antigens, LCM was prepared from the soluble fraction composed of 70K, 59K, 49K, and 31K proteins. These proteins of LCM were included in liver specific lipoprotein (LSP). The number of LCM proteins was limited to 4, although that of LSP was 8 or more. Furthermore, circulating antibodies against "LCM" were detected in patients with chronic liver diseases type B and autoimmune hepatitis by an 125I-LCM-IgG-Protein A method. Therefore, LCM may be more useful than LSP to study the immunological responses involved in liver diseases.

Animals↗

Molecular hybridization methods for determination of serum HBV-DNA.

Molecular hybridization methods for determination of hepatitis B virus DNA (HBV-DNA) in serum were studied. A simple method by which serum was treated with sodium hydroxide, followed by dot hybridization procedure on filter sheets provides a sensitive and direct result for detecting HBV-DNA. Another method in which DNAs extracted from Dane particle fraction were subjected to the molecular hybridization method on a filter membrane, provided similar results although this method is time consuming. The third method in which serum was directly spotted on filter sheets, followed by alkaline-treatment seems to be less sensitive. Three filter papers, NC filter, Zeta-Probe and Biodyne, on which molecular hybridization was performed, gave similar sensitivity.

DNA, Viral↗

Cytoskeletal organization in the supporting cell of the guinea pig organ of Corti.

The rapid-freeze, deep-etch method was used to visualize the three-dimensional organization of cytoskeletons in the supporting cells of the guinea pig organ of Corti. Deep-etched replicas showed that both the head and basal portions of the pillar cell were composed of a filamentous network consisting of several kinds of fibrous elements, into which numerous microtubules and actin filaments were tightly inserted. Myosin S1-decoration showed that the main constituent element in such filamentous networks in the basal portion of the pillar cell was the actin and tiny cross-bridges interconnected the randomly oriented adjacent actin filaments.

Actin Cytoskeleton↗

Human hepatocellular carcinoma-associated changes of glycosphingolipids detected by two monoclonal antibodies FH2 and IB9.

The changes of minor glycosphingolipids associated with human hepatocellular carcinomas were studied using monoclonal antibodies. Glycosphingolipids of twelve patients were isolated from the tumor tissues and their adjacent cirrhotic liver tissues. The immunoreactivities of glycosphingolipids with two monoclonal antibodies FH2 and IB9, that define x-structure (Gal beta 1-4[Fuc alpha 1-3]GlcNAc) and sialosyl alpha 2-6galactosyl residue, respectively, were studied by a solid phase enzyme-linked immunosorbent assay and a chromatogram immunobinding assay. X-structure was detected in the upper-phase neutral glycosphingolipids from both the cirrhotic liver tissues and the tumor tissues, but was generally expressed more strongly in the latter tissues. The thin-layer chromatography patterns of x-active glycosphingolipids were more complex in the tumor tissues. Sialosyl alpha 2-6galactosyl residue was detected in two ganglioside fractions. One ganglioside with faster migration on a thin-layer chromatogram was found in both the non-tumorous tissues and the tumor tissues. Another ganglioside with slower migration was more often detected in the tumor tissues. It was concluded that some of minor glycosphingolipids detected by monoclonal antibodies FH2 and IB9 could be the 'tumor-associated' antigens.

Antibodies, Monoclonal↗

Structural similarities between kinocilium of vestibular hair cell and tracheal motile cilium in the guinea pig.

A rapid-freeze, deep-etch method was used to visualize the membrane characteristics as well as the three-dimensional ultrastructural features of a kinocilium of the guinea pig vestibular hair cell. A kinocilium of the vestibular hair cell had a typical ciliary necklace, consisting of six to seven parallel intramembrane particle arrays. The basal body of a kinocilium had a plate-structure called a terminal plate, in its interior. In the shaft region of a kinocilium, peripheral microtubules were connected to the central microtubules by periodic tiny linkers, called radial spokes. These structural features of a kinocilium were identical to those of the tracheal motile cilium.

Animals↗

State of hepatitis B viral DNA in the liver of patients with hepatocellular carcinoma and chronic liver disease.

In order to clarify the relationship between the integration of hepatitis B virus (HBV) DNA and human hepatocellular carcinoma (HCC), the states of HBV DNA in liver tissues were examined by the Southern blot hybridization procedure. Integration of HBV DNA was found in 12 of 25 HCC cases and 5 of 12 cirrhotic cases. Of these 17 cases, 11 were positive for serum hepatitis B virus surface antigen (HBsAg) and the remaining six were positive for more than one of the serum HBV-related antibodies. In all three cases of chronic hepatitis and 18 controls, integration of HBV DNA could not be detected. Free viral DNA was found in 12 of 15 cases with serum HBsAg. One patient without serum HBsAg also had free viral DNA in the liver. Integration of HBV DNA could be observed in HCC cases positive for serum HBsAg at the highest frequency. However, there was one HCC case from an HBsAg carrier in whom integration of HBV DNA might not have a causal effect on malignant transformation, because integrated HBV DNA could be detected only in a non-tumor region. Since integrated HBV DNA could not be detected in 13 of 25 HCC cases, other etiologic factors than the integration of HBV DNA must also be taken into consideration for HCC.

Adult↗

Comparison of effects of tiapride and sulpiride on D-1, D-2, D-3 and D-4 subtypes of dopamine receptors in rat striatal and bovine caudate nucleus membranes.

To determine the affinity of tiapride to D-1, D-2, D-3 and D-4 subtypes of dopamine (DA) receptors, inhibitory effects of tiapride on [3H]-cis-flupenthixol, [3H]spiperone and [3H]N-propylapomorphine binding were examined in the rat striatum and bovine caudate nucleus membranes and compared to those of sulpiride and haloperidol. The IC50 values of tiapride, sulpiride and haloperidol were estimated as follows: 1440, 132 and 0.295 microM for D-1; 45.8, 8.8 and 0.004 microM for D-2; greater than 100, greater than 100 and 0.64 microM for D-3; 11.7, 2.88 and 0.0044 microM for D-4, respectively. It is suggested that the affinity of tiapride is high to D-2 and D-4, but is not high to D-1 and D-3. The affinity pattern of tiapride to each DA receptor subtype is similar to but lower than those of sulpiride and haloperidol. In the D-2 receptor assay, the IC50 values of tiapride and sulpiride were 1/22.7 and 1/19.1 of those in the presence of 100 mM NaCl, respectively, suggesting that benzamide drug binds to the D-2 subtype with higher affinity in the presence of Na+ than in the control.

Animals↗