Search PubMed⌕ Search

Biomedical subjects

A Matsumoto

Publications and source records attributed to A Matsumoto.

At least 19 recordsLinked to original sources
PubMed1992

Expression of scavenger receptors on renal cell carcinoma cells in vitro.

Messenger RNAs and proteins of scavenger receptor thought to be macrophage specific protein were expressed in renal cell carcinoma (RCC) cells in vitro. Acetyl LDL was taken up into RCC cells and promoted the production of interleukin-6 (IL-6), an in vitro autocrine growth factor to proliferate the cells. These results suggested that RCC cells might have a scavenger pathway which has not yet been demonstrated except for macrophages.

Blotting, Northern↗
PubMed1992

Genetic analysis of a Japanese family with normotriglyceridemic abetalipoproteinemia indicates a lack of linkage to the apolipoprotein B gene.

Normotriglyceridemic abetalipoproteinemia is a rare familial disorder characterized by an isolated deficiency of apoB-100. We have previously reported a patient with this disease, who had normal apoB-48 but no apoB-100. To elucidate the genetic abnormalities in this family, we studied the linkage of apoB gene using three genetic markers. The proband and her affected brother showed completely different apoB gene alleles, suggesting that the apoB gene itself is not related to this disorder in this family. By contrast, an American case had a point substitution in the apoB gene generating an in-frame stop codon. These results indicate that this disorder can be caused by defect(s) of either an apoB gene or other genes.

Abetalipoproteinemia↗
PubMed1992

Detection of chronic hepatitis C virus infection by four diagnostic systems: first-generation and second-generation enzyme-linked immunosorbent assay, second-generation recombinant immunoblot assay and nested polymerase chain reaction analysis.

Serum samples from 100 patients with non-A, non-B hepatitis-related chronic liver disease and 100 patients with hepatitis B-related chronic liver disease were tested by first-generation and second-generation enzyme-linked immunosorbent assays, a second-generation recombinant immunoblot assay and the nested polymerase chain reaction. In non-A, non-B hepatitis-related chronic liver disease, second-generation enzyme-linked immunosorbent assay (anti-c22 and/or c200) and second-generation recombinant immunoblot assay showed 98% positivity, whereas first-generation enzyme-linked immunosorbent assay (anti-c100-3) showed 89% positivity. The two second-generation recombinant immunoblot assay-negative samples were positive by nested polymerase chain reaction, but one second-generation recombinant immunoblot assay-positive sample was polymerase chain reaction negative. However, when this second-generation recombinant immunoblot assay-positive sample was tested by polymerase chain reaction using another set of primers, it was polymerase chain reaction positive. Therefore, 100% of the non-A, non-B hepatitis-related chronic liver disease serum samples were hepatitis C virus RNA positive by polymerase chain reaction. Nine hepatitis B-related chronic liver disease samples were first-generation enzyme-linked immunosorbent assay positive. Of the eight second-generation enzyme-linked immunosorbent assay-positive hepatitis B-related chronic liver disease samples, six were first-generation enzyme-linked immunosorbent assay positive and five were second-generation recombinant immunoblot assay positive and polymerase chain reaction positive. One indeterminate second-generation recombinant immunoblot assay sample was polymerase chain reaction negative. Therefore, second-generation recombinant immunoblot assay appears to be as useful as polymerase chain reaction for detecting a chronic hepatitis C virus infection, although some discrepancies were noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

A new technique of hepatectomy using an occlusion balloon catheter for the hepatic vein.

To minimize intraoperative bleeding and allow more accurate resection, we have devised a new technique for hepatectomy. In addition to occlusion of the afferent vessels, we occlude the hepatic vein at the hepatocaval junction using a balloon catheter inserted transhepatically under intraoperative ultrasonic guidance. We have performed eight hepatectomies using this method. A sequence of 15 minutes of vascular occlusion followed by 5 minutes reperfusion was repeated throughout the operation, and the total ischemic time ranged from 45 to 90 minutes. This method greatly decreased intraoperative bleeding without causing significant elevation of the postoperative transaminase or lactic dehydrogenase levels when compared with occlusion of only the afferent vessels or nonischemic resection using a microwave tissue coagulator in patients undergoing equivalent resections. Also, the postoperative prothrombin time recovered to a significantly higher level, and there were no fatal postoperative complications using this method. Our method is useful for systematic hepatic resection along the hepatic vein or for resection of tumor sited at the confluence of the hepatic vein.

Aged↗
PubMed1992

Changes in protein kinase C activity in rat calvarial bone cells cultured in a low-calcium environment.

This enzyme activity was examined in bone cells cultured for 8-10 days; the calcium concentration was 1.87 +/- 0.05 (n = 10) mM in the control medium and 0.34 +/- 0.02 (n = 10) mM in the low-calcium medium. The activity was significantly lower in the low-calcium group than in the control (p less than 0.01). The cytosolic fraction decreased more than the membranous fraction. After restoration to a regular calcium environment, the protein kinase C activity recovered rapidly to near the control value. The extent of recovery was greater in the membranous than in the cytosolic fraction. These results suggest that the enzyme was inhibited in bone cells placed in a low-calcium environment, while the sensitivity in the membrane was enhanced.

Animals↗
PubMed1992

Effect of androgen on the expression of gap junction and beta-actin mRNAs in adult rat motoneurons.

Expression of gap junction and beta-actin mRNAs was examined in androgen-sensitive motoneurons of the spinal nucleus of the bulbocavernosus (SNB) in adult male rats by in situ hybridization histochemistry using complementary DNAs encoding rat liver gap junction protein (connexin 32) and chick beta-actin. Hybridizable gap junction and beta-actin mRNAs were localised on the somata and proximal dendrites of SNB motoneurons. Removal of androgen by castration significantly reduced the expression levels of both gap junction and beta-actin mRNAs in the SNB motoneurons, whereas these changes were prevented by testosterone treatment. On the contrary, castration or testosterone treatment did not induce any changes in the expression levels of gap junction and beta-actin mRNAs in the motoneurons of the retrodorsolateral nucleus (RDLN), which accumulate androgen less frequently and sparsely than those in the SNB. These results suggest that androgen regulates the expression of both gap junction and beta-actin genes in the SNB motoneurons and may provide evidence for the molecular mechanisms of hormonally induced neuronal plasticity in the SNB motoneurons.

Actins↗
PubMed1992

Effects of milrinone on lung water content in dogs with acute pulmonary hypertension.

To evaluate the effects of milrinone (MIL) on hemodynamics and lung water content, we used 10 mongrel dogs with pulmonary hypertension (PH). To induce pulmonary hypertension, we administered two injections of glass beads stirred in saline to dogs. Mean pulmonary arterial pressure (PAP) and pulmonary vascular resistance significantly increased following induction. Milrinone, which inhibits cyclic AMP phosphodiesterase-(PDE) demonstrated pulmonary vasodilation, indicated a reduction in these two parameters. To clarify the drug mechanism, we measured lung water content as extravascular lung thermal volume (ETVL) using a thermo/sodium double-indicator dilution method. The induction of pulmonary hypertension produced a transient reduction in extravascular lung thermal volume. The parameter remained constant following milrinone administration, whereas the control showed a gradual increase. Of the 10 dogs, five were killed to measure gravimetrically the volume of lung water content as a comparison with extravascular lung thermal volume. We concluded that milrinone produced pulmonary vasodilation which induced a reduction in the transmural capillary pressure gradient according to Starling's hypothesis. This study suggests that the reduction in the transmural pressure gradient induced by milrinone may also prevent the re-elevation in extravascular lung thermal volume. Milrinone increases the cyclic AMP level in the endothelium and in the platelet which may affect either directly or indirectly the permeability of capillary endothelium.

Acute Disease↗
PubMed1992

Effects of anti-acid secretory agents on various types of gastric mucus.

Total, acidic, and sulfated mucus contents in the gastric mucosa were evaluated after administration to rats of ranitidine and pirenzepine, antagonists of gastric parietal cell receptors; omeprazole, a proton-pump/inhibitor; and misoprostol, a prostaglandin E1 preparation. Total gastric mucus content was significantly decreased by ranitidine, but contents of acidic mucus and sulfated mucus showed a slight increase. Total mucus and acidic mucus contents were slightly increased after administration of pirenzepine, whereas the sulfated mucus content was significantly increased. The total gastric mucus content was significantly decreased after administration of omeprazole, but acidic mucus increased slightly and sulfated mucus increased significantly. All mucus contents were unchanged after administration of anti-acid secretory dose of midoptodyol. After administration of either ranitidine or omeprazole, the neutral mucus content decreased, but the total acid and sulfated mucus contents were not decreased. Changes in various mucus contents following inhibition of acid secretion are different for different drugs, and it was suggested that production of neutral mucus and secretion of acid mucus were reduced by strong inhibition of acid secretion.

Animals↗
PubMed1992

[Development of serodiagnostic kit "HITAZYME Chlamydia Ab" for Chlamydia trachomatis infections using extracted antigen].

To develop EIA kit with low cross-reactivity for the quantitative detection of anti-chlamydial antibodies, we examined the preparation of trachomatis antigens and its specificity to mouse antisera and human sera. The chlamydial elementary body (EB) purified from C. trachomatis L2/434/Bu strain was treated by Sarkosyl, dithiothreitol and SDS by turns to obtain the soluble EB outer membrane (COMC). SDS-PAGE showed that the major components of the COMC were 96K, 60K and 39.5 KDa peptides. The reactivity of the COMC immobilized to 96 wells microtiter plate to mouse anti-serum to C. trachomatis was higher than the other two mouse anti-sera to C. psittaci and pneumoniae. In human sera, the cut off values were calculated from an average optical density plus its two-fold standard deviation obtained by the testing of 100 samples of healthy human sera. We evaluated the specificity of the kit to 17 anti-C. pneumoniae, 9 C. trachomatis and 4 C. psittaci antibodies positive patients' sera judged by the MFA method respectively. The results showed that the concordance ratio of IgG and IgA were 88%, 100% in anti-C. pneumoniae, 89%, 78% in anti-C. trachomatis and 50%, 50% in anti-C. psittaci respectively. From the results obtained in this study, we concluded that the HITAZYME method which had a very low cross-reactivity to C. pneumoniae is clinically useful in the serodiagnosis of C. trachomatis infections, even if it has a little common antigenicity with C. psittaci antigen.

Adolescent↗
PubMed1992

Anti-human immunodeficiency virus activity of a novel synthetic peptide, T22 ([Tyr-5,12, Lys-7]polyphemusin II): a possible inhibitor of virus-cell fusion.

More than 40 peptides associated with tachyplesin and polyphemusin, which are highly abundant in hemocyte debris of the horseshoe crabs Tachypleus tridentatus and Limulus polyphemus, were synthesized. Among these peptides, we found that a novel compound, which was called T22 ([Tyr-5,12, Lys-7]polyphemusin II), strongly inhibited the human immunodeficiency virus type 1 (HIV-1)-induced cytopathic effect and viral antigen expression. Its 50% effective concentration was 0.008 micrograms/ml, while its 50% cytotoxic concentration was 54 micrograms/ml. The anti-HIV activity of T22 was observed with several strains of HIV-1, including zidovudine-resistant strains, and with HIV-2 within the concentration range of 0.006 to 0.071 microgram/ml. T22 efficiently inhibited giant cell formation on the cocultivation of MOLT-4/HIV and MOLT-4 cells but modestly inhibited direct HIV binding. T22 did not inhibit reverse transcriptase activity. A time-of-addition study, which involved monitoring of the appearance of proviral DNA by using the polymerase chain reaction technique, found that T22 exerted its effect on a process, most probably virus-cell fusion or uncoating, immediately after virus adsorption.

Amino Acid Sequence↗
PubMed1992

Establishment of a particle-counting method for purified elementary bodies of chlamydiae and evaluation of sensitivities of the IDEIA Chlamydia kit and DNA probe by using the purified elementary bodies.

To evaluate the sensitivity of commercially available test kits for detection of chlamydiae, we established a method of purifying Chlamydia trachomatis and Chlamydia pneumoniae elementary bodies (EBs). We then subjected the purified EBs, together with the purified EBs of Chlamydia psittaci, to the IDEIA Chlamydia (IDEIA) and DNA probe test kits to determine the EB numbers at the detection limits. The sensitivities of the test kits were thus compared. The results can be summarized as follows. (i) Intact EBs in the purified preparations were present at 100, 96.3, and 97% for the C. psittaci Cal 10, C. trachomatis L2/434/Bu (L2), and C. pneumoniae TW-183 strains, respectively. The preparations of the L2 and TW-183 EBs contained a few EB envelopes, which reacted with antilipopolysaccharide monoclonal antibodies, as did the intact EBs, indicating that elimination of EB envelopes is not required for testing of the IDEIA kit's sensitivity. (ii) We established a method of counting intact EBs and EB envelopes under a scanning electron microscope after sedimentation of EBs on a coverslip by centrifugation. (iii) The EB numbers per assay at the cutoff level, which is set up in the IDEIA kit, were 9.6 x 10(2), 6.5 x 10(3), and 2.5 x 10(4) for the L2, TW-183, and Cal 10 strains, respectively. When the same EB preparations were applied to the DNA probe kit, the EB number at the cutoff level was 7.5 x 10(3) per assay for the L2 strain, but no reaction occurred for the Cal 10 and TW-183 strains at any EB number, indicating that the DNA probe kit is highly specific for C. trachomatis. Although the IDEIA kit designed for detection of C. trachomatis showed a sensitivity superior to that of the DNA probe, the chlamydial species was not determined by the IDEIA kit.

Bacteriological Techniques↗
PubMed1992

An immunohistochemical study of the distribution of immunocompetent cells, especially macrophages and Ia antigen-expressing cells of heterogeneous populations, in normal rat molar pulp.

The precise distribution of various immunocompetent cells in rat molar pulp was immunohistochemically examined by use of seven anti-rat monoclonal antibodies. It was demonstrated that rat molar pulp contained many OX6 (anti-Ia antigen)-positive cells and a large number of ED1 (anti-monocytes, macrophages, and dendritic cells)-positive, ED2 (anti-tissue macrophages)-positive, and/or OX35 (anti-macrophages and CD4+ lymphocytes)-positive cells. Macrophage-like cells predominated in the central portion of the pulp, while cells of dendritic appearance usually existed in the periphery of the pulp. Double-immunoperoxidase staining revealed that these cells showed some heterogeneity, but the majority could be classified as ED1+/OX6-/ED2+ cells, which may be Ia-histiocytes. Findings also suggested that true dendritic cells may be included in the ED1+/OX6+/ED2- category of cells. A small number of T lymphocytes and plasma cells were also detected. These results suggest that the normal dental pulp contains a variety of immunocompetent cells, with macrophages as the most dominating. Following the exogenous invasion of pathogenic stimuli in the pulp, these cells may participate in the defense reaction by acting as phagocytes or antigen-presenting cells, which are essential for the initiation of immune responses.

Animals↗
PubMed1992

Effects of pravastatin sodium alone and in combination with cholestyramine on hepatic, intestinal and adrenal low density lipoprotein receptors in homozygous Watanabe heritable hyperlipidemic rabbits.

Pravastatin sodium (pravastatin), a tissue-selective inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, was administered alone (50 mg/kg) or in combination with cholestyramine, a bile acid sequestrant resin, at the level of 2% in the diet to homozygous Watanabe heritable hyperlipidemic (WHHL) rabbits for 4 weeks. The low density lipoprotein (LDL)-cholesterol levels were reduced by 29% and 56% with pravastatin alone and the combination treatment, respectively. Hepatic LDL receptor activity was increased by 11.2- and 13.9-fold with pravastatin alone and the combination treatment, respectively. The LDL receptor activity in the untreated homozygous WHHL rabbits was only 2.5% of that in the normal rabbits. mRNA for the LDL receptor in the liver was also increased by 2.1- and 3.4-fold with pravastatin alone and the combination treatment, respectively. On the other hand, mRNA for the LDL receptor in the adrenal gland was not affected by pravastatin and the combination treatment, whereas the mRNA in the intestine was increased in both groups. These results suggest the following: 1) the induction of hepatic LDL receptor activity by the treatment of pravastatin alone or in combination with cholestyramine is the main cause of the reduction of serum cholesterol levels by these treatments even in LDL receptor-deficient animals. 2) The induction of the mRNA for the LDL receptor in the liver and intestine, but not that in the adrenal gland, might be a reflection of the tissue-selective inhibition of cholesterol synthesis by pravastatin.

Adrenal Glands↗
PubMed1992

Multiple sclerosis in Hokkaido, the northernmost island of Japan: prospective analyses of clinical features.

We analyzed the clinical features of multiple sclerosis (MS) prospectively seen between July 1986 and October 1989 on Hokkaido island, the northernmost part of Japan. Clinical features were generally considered to be intermediate between the previous Japanese reports and those of Western countries. Devic's disease was rare and simultaneous bilateral visual loss at on set was not too common this series, differing from that previously reported of Japanese MS. The high incidence of acute transverse myelopathy and lesser involvement of the cerebellum, however, support the previous view. Further clinical and epidemiological studies will be necessary on this island.

Adult↗
PubMed1992

[Pulmonary arteriovenous malformation with systemic blood supply].

A forty-eight year-old woman who had suffered from exertional dyspnea and cyanosis since her youth was found to have abnormal shadow in her right lower lung at the roentgenographic examination. Pulmonary angiography showed cavernous network between pulmonary artery and vein of the 8th, 9th, and 10th segments. Bronchial artery was dilated, supplying the cavernous lesion. From these findings this lesion was diagnosed as pulmonary arteriovenous malformation feeded by bronchial artery. Right lower lobectomy was performed. The effect of resection was confirmed by intraoperative arterial gas analysis before and after the excision. She has been doing well without any signs of recurrence for 3 years after the surgery.

Arteries↗