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Biomedical subjects

K Matsuda

Publications and source records attributed to K Matsuda.

At least 253 records · Page 14Linked to original sources
PubMed1998

Selective proliferation of lymphoid cells from lineage-c-Kit+ Sca-1+ cells by a clonal bone marrow stromal cell line.

To understand the regulatory mechanisms involved in the development of hematopoietic stem cells, we cultured lineage-negative, c-Kit+ Sca-1+ stem cells sorted from bone marrow cells by a fluorescence-activated cell sorter (FACS) on layers of bone marrow stromal cell lines established from SV40 T-antigen gene transgenic mice. We previously reported that the TBR59 stromal cell line induced two sequential cobblestone formations: the first formation committed to the myeloid and the second to the lymphoid lineage. After examination of many other bone marrow stromal cell lines, we found that TBR31-1 stromal cells supported only lymphoid development of the sorted stem cells. The sorted stem cells proliferated by forming cobblestones and the cells were released from the cobblestones. Most released cell populations were B220-positive lymphoid cells; cell production continued for 2 months. Addition of G-CSF or M-CSF produced only a slight effect on myeloid development. FACS analysis of the released cells showed that the B-lymphoid-committed progenitors developed into mature B-cells by expressing surface immunoglobulin M. These results indicate that TBR31-1 bone marrow stromal cells selectively support B-lymphoid development, whereas TBR59 cells support both myeloid and lymphoid development of stem cells.

Animals↗
PubMed1997

Structure of a novel phosphocholine-containing aminoglycoglycerolipid of Mycoplasma fermentans.

Mycoplasma fermentans is thought to be a pathogen of rheumatoid arthritis or a cofactor of AIDS (acquired immunodeficiency syndrome). To elucidate the possible involvement of membrane constituents in the pathogenesis of these diseases, we studied its lipid components. Several alkali labile glycophospholipids were detected and named glycoglycerophospholipids (GGPLs). Previously, we purified and determined the structure of one of them as 6'-O-phosphocholine-alpha-glucopyranosyl-(1'-3)-1,2-diacyl-sn-glycerol (GGPL-I). The present paper describes the purification and structural characterization of GGPL-III, the major GGPL of M. fermentans using 1H-, 13C- and 31P-nuclear magnetic resonance spectroscopy, and mass-spectroscopy as 1"-phosphocholine,2"-amino dihydroxypropane-3"-phospho-6'-alpha-glucopyranosyl-(1'-3)-1,2-dia cyl-glycerol.

Glycolipids↗
PubMed1997

Adenovirus-mediated gene transfer of C-type natriuretic peptide causes G1 growth inhibition of cultured vascular smooth muscle cells.

We have proposed the "vascular natriuretic peptide system", in which C-type natriuretic peptide (CNP), the third member of the natriuretic peptide family, can control vascular tone and growth as an endothelium-derived relaxing peptide. We aimed at overexpression of CNP gene in vascular smooth muscle cells (SMCs) by adenovirus-mediated gene transfer to examine the growth characteristics of SMCs via the augmentation of cGMP production. Rat aortic SMCs infected with Ad.CNP, a replication-deficient adenovirus driving rat CNP cDNA, produced 162 +/- 55 fmol/mL of CNP, which was 4,000 times higher than that produced by endothelial cells. cGMP production was also augmented in Ad.CNP-infected SMCs (2200 +/- 270 fmol/10(4) cells). Accordingly, significant growth inhibition was observed in SMCs infected with Ad.CNP. The flow cytometry analysis revealed that the population of the S and G2 + M phases was reduced by 60% of the control in Ad.CNP-infected SMCs. The gene expression of ANP-B receptor, which is expressed abundantly in SMCs with the synthetic phenotype, was suppressed in Ad.CNP-infected SMCs, while the gene expression of ANP-A receptor, which is expressed predominantly in SMCs with the contractile phenotype, became detectable in Ad.CNP-infected SMCs. In addition, the gene expression of smooth muscle myosin heavy chain-2 (SM-2), which is the molecular marker of highly-differentiated SMCs, was also induced in Ad.CNP-treated SMCs. These results suggest that cGMP cascade activation induces re-differentiation of SMCs. The present study demonstrated that overexpression of CNP induced growth inhibition of SMCs at the G1 phase with possible alteration of the phenotype.

Adenoviridae↗
PubMed1997

Detection of serum antibodies against phosphocholine-containing aminoglycoglycerolipid specific to Mycoplasma fermentans in HIV-1 infected individuals.

Mycoplasma fermentans has been associated with acquired immunodeficiency syndrome (AIDS). The lipids extracted from five strains of M. fermentans and eight other species of mycoplasmas were investigated. By using high-performance thin-layer chromatography (HPTLC) and immunostaining on HPTLC-plates with polyclonal and monoclonal antibodies against lipids of M. fermentans, a glycophospholipid GGPL-III was proved to be a specific lipid and important antigen of the species of M. fermentans. Previously we reported that M. fermentans had phosphocholine-containing glycoglycerolipid (GGPL-I and GGPL-III). TLC immunostaining showed that anti-GGPL-III specific antibodies were detected in HIV-1 infected individuals. By employing purified GGPL-III, an enzyme-linked immunosorbent assay (ELISA) has been developed for the detection of specific antibodies to GGPL-III in human serum. This ELISA showed high sensitivity, specificity and good reproducibility. Frequency of antibodies to GGPL-III was significantly higher in sera from HIV-1 infected people (44.6%, 29/65) than from HIV-1 negative healthy donors (1.7%, 2/117) or patients with three kinds of other diseases we investigated (0-8.7%, 0/20-2/23). Thus M. fermentans infection seemed to be correlated with HIV-1 infection although further investigation is essential for clarification of the role of M. fermentans during the long latency period in HIV infected individuals.

Antibodies, Bacterial↗
PubMed1997

Neuronal nicotinic acetylcholine receptor in the hypothalamus: morphological diversity and neuroendocrine regulations.

The subcellular localization and functional significance of neuronal nicotinic acetylcholine receptor alpha4-subunits were investigated in the rat hypothalamic supraoptic nucleus. A high level of alpha4 mRNA expression was found in the magnocellular neurons in the supraoptic nucleus. Strong immunoreactitivy for alpha4 in neurons of the supraoptic nucleus was detected in the rough endoplasmic reticulum and cytoplasmic matrix, although it was very weak in the Golgi apparatus, except for the transport vesicles. Immunoreactivity for alpha4 was detected in both the pre-synaptic axon terminals and post-synaptic axon terminals. A high level of signals for vasopressin mRNA was detected in the supraoptic nucleus after the animals were injected s.c. with nicotine. These findings suggest that alpha4-containing subtypes are synthesized in the rough endoplasmic reticulum and transported to the plasma membrane and serve as pre- and post-synaptic nicotinic acetylcholine receptors. Nicotine may up-regulate vasopressin gene expression in the supraoptic nucleus, acting through nicotinic acetylcholine receptors.

Animals↗
PubMed1997

Caenorhabditis elegans levamisole resistance genes lev-1, unc-29, and unc-38 encode functional nicotinic acetylcholine receptor subunits.

We show that three of the eleven genes of the nematode Caenorhabditis elegans that mediate resistance to the nematocide levamisole and to other cholinergic agonists encode nicotinic acetylcholine receptor (nAChR) subunits. unc-38 encodes an alpha subunit while lev-1 and unc-29 encode non-alpha subunits. The nematode nAChR subunits show conservation of many mammalian nAChR sequence features, implying an ancient evolutionary origin of nAChR proteins. Expression in Xenopus oocytes of combinations of these subunits that include the unc-38 alpha subunit results in levamisole-induced currents that are suppressed by the nAChR antagonists mecamylamine, neosurugatoxin, and d-tubocurarine but not alpha-bungarotoxin. The mutant phenotypes reveal that unc-38 and unc-29 subunits are necessary for nAChR function, whereas the lev-1 subunit is not. An UNC-29-GFP fusion shows that UNC-29 is expressed in body and head muscles. Two dominant mutations of lev-1 result in a single amino acid substitution or addition in or near transmembrane domain 2, a region important to ion channel conductance and desensitization. The identification of viable nAChR mutants in C. elegans provides an advantageous system in which receptor expression and synaptic targeting can be manipulated and studied in vivo.

Amino Acid Sequence↗
PubMed1997

Determination of N-(trans-4-isopropylcyclohexanecarbonyl)-D-phenylalanine and its metabolites in human plasma and urine by column-switching high-performance liquid chromatography with ultraviolet detection.

A simple, rapid and sensitive two column-switching high-performance liquid chromatographic (HPLC) method with ultraviolet detection at 210 nm has been developed for the determination of N-(trans-4-isopropylcyclohexanecarbonyl)-D-phenylalanine (AY4166, I) and its seven metabolites in human plasma and urine. Measurements of I and its metabolites were carried out by two column-switching HPLC, because metabolites were classified into two groups according to their retention times. After purification of plasma samples using solid-phase extraction and direct dilution of urinary samples, I and each metabolite were injected into HPLC. The calibration graphs for plasma and urinary samples were linear in the ranges 0.1 to 10 microg ml(-1) and 0.5 to 50 microg ml(-1), respectively. Recoveries of I and its seven metabolites were over 88% by the standard addition method and the relative standard deviations of I and its metabolites were 1-6%.

Chromatography, High Pressure Liquid↗
PubMed1997

Phosphocholine-containing glycoglycerolipids (GGPL-I and GGPL-III) are species-specific major immunodeterminants of Mycoplasma fermentans.

Mycoplasma fermentans has unique glycoglycerophospholipids (GGPLs: GGPL-I and GGPL-III). Previously, the structure of these lipids was determined as phosphocholine-6'-alpha-glucopyranosyl-(1'-3)-1, 2-diacyl-glycerol (GGPL-I) and 1"-phosphocholine-2"-aminodihydroxypropane-3"-phospho-6'-alph++ + a- glucopyranosyl-(1'-3)-1, 2-diacyl-glycerol (GGPL-III). Thin-layer chromatography (TLC) immunostaining showed that the GGPLs were main lipid-antigens of the M. fermentans species. Anti-M. fermentans serum stained mainly the GGPLs, but the other anti-mycoplasma sera (anti-M. arginini, anti-M. hyorhinis, anti-M. pneumonia, anti-M. primatum, and anti-Acholeplasma laidlawii, anti-M. hominis, anti-M. orale, and M. salivarium) stained neither GGPL-I nor GGPL-III. The TLC analysis of glycolipids and phospholipids of various human related mycoplasmas showed clearly that GGPLs are specifically expressed in M. fermentans species. GGPL-I and GGPL-III ranged from 1.6 to 28% and from an undetectable level to 35% of total phospholipids, respectively. Although there was heterogeneity among the amounts of GGPL-I or GGPL-III of M. fermentans strains, all of the M. fermentans strains had GGPL-I and/or GGPL-III. These observations showed that GGPL structures are species-specific immunodeterminants of M. fermentans. The fact that the GGPLs are main phospholipid components of the M. fermentans species means the M. fermentans has a unique choline metabolic pathway. This observation may raise phylogenetic interest.

Animals↗
PubMed1997

ERC-55, a binding protein for the papilloma virus E6 oncoprotein, specifically interacts with vitamin D receptor among nuclear receptors.

VDR regulates gene expression in a ligand-dependent way by binding to cognate enhancer elements of target gene promoters. The ligand-dependent activation function, AF-2, of VDR is thought to require transcriptional co-activators/co-repressors together with basal transcriptional machinery. Using a yeast two hybrid system with VDR, we have isolated a mouse Ca(2+)-binding protein (designated as VAF1) specifically interacting in vivo and in vitro with VDR among nuclear receptors like RAR, RXR, ER and GR. VAF1 is a mouse homologue to human ERC-55, which has recently been shown to interact with human papillomavirus oncogenic protein, E6[1]. Unlike those of many previously identified co-activators, the VDR-VAF1 interaction was ligand-independent. Thus, VAF1 seems a putative VDR-specific cofactor modulating its function.

Amino Acid Sequence↗
PubMed1997

Enhanced cytokine production by milk macrophages following infection with respiratory syncytial virus.

Paired samples of milk and serum collected 3 days postpartum from 20 women were tested for the presence and level of interleukin (IL)-1, IL-6, IL-12, tumor necrosis factor alpha (TNF-alpha), and interferon-gamma (IFN-gamma) by enzyme immunoassay. The expression of these cytokine mRNAs in milk macrophages from eight donors were semiquantitatively analyzed by reverse transcriptase-polymerase chain reaction. The effects of respiratory syncytial virus (RSV) infection on cytokine production were determined in five samples of milk macrophages. Over 90% of the milk samples tested exhibited detectable levels of IL-1beta, IL-6, and TNF-alpha. No IL-12 or IFN-gamma activity was detected in the milk. IL-6 activity was weakly detected in about 45%, and TNF-alpha activity in about 10% of the serum samples tested. However, no IL-1beta, IL-12, or IFN-gamma activity was demonstrated in any of the serum samples. Milk macrophages from eight subjects all exhibited mRNA for IL-1beta, TNF-alpha, and IL-6, and IFN-gamma mRNA in six of eight subjects, although no IFN-gamma was detected in any of the 20 samples of milk tested. RSV exposure resulted in a 2- to 100-fold increase in the expression of IL-1beta, IL-6, and TNF-alpha mRNA as well as cytokine protein. Although RSV infection enhanced the expression of IFN-gamma mRNA, no detectable IFN-gamma was produced by the milk macrophages. These observations suggest that the milk macrophages are actively engaged in the physiological production of IL-1beta, IL-6, TNF-alpha, and IFN-gamma in the mammary gland and continue to possess the capacity to increase production of these cytokines in response to RSV and possibly other viral infections.

Cytokines↗
PubMed1997

Occult lymph node metastases detected by cytokeratin immunohistochemistry predict recurrence in "node-negative" colorectal cancer.

There is controversy about the prognostic significance of occult lymph node metastases detected by immunohistochemistry with the anti-cytokeratin antibody CAM 5.2. The aim of this study was to characterize occult lymph node metastases in colorectal carcinomas that might be associated with a higher risk of recurrence. Three hundred fifty-eight lymph nodes from 10 recurrent and 9 nonrecurrent cases of colorectal carcinoma were examined. All these patients had been reported originally as having no lymph node metastases by routine hematoxylin and eosin staining. Three 10-micron sections or ten 3-micron sections (30-micron total thickness) from each lymph node were stained with CAM 5.2 and examined for the presence of occult lymph node metastases. Occult metastases were detected in 67 of 175 lymph nodes from the recurrent cases, and in 23 of 183 lymph nodes from the nonrecurrent cases. The frequency of positive nodes was significantly higher in the recurrent cases. The recurrent cases had metastases in nodes more distant from the main tumor than did the nonrecurrent cases. Detection of occult lymph node metastases with cytokeratin immunohistochemistry may make it possible to identify patients with a higher risk of recurrence after the removal of a primary colorectal tumor.

Adult↗
PubMed1997

Regional cerebral blood flow and oxygen metabolism in a patient with Korsakoff syndrome.

We report a functional neuroimaging study of a patient clinically diagnosed with Korsakoff syndrome. Positron emission tomography (PET) with the 15O inhalation method showed decreased regional cerebral blood flow (rCBF) and decreased regional cerebral metabolic ratio for oxygen (rCMRO2) in the bilateral fronto-temporal areas and in the left thalamus. These results suggest that dysfunction of the frontal-thalamic neural network plays a role in the disturbance of Korsakoff syndrome.

Alcohol Amnestic Disorder↗
PubMed1997

Plasma levels of brain and atrial natriuretic peptides elevate in proportion to left ventricular end-systolic wall stress in patients with aortic stenosis.

Brain natriuretic peptide (BNP) is a novel cardiac hormone secreted predominantly from the ventricle. We examined the plasma levels of BNP and atrial natriuretic peptide (ANP) in 13 patients with aortic stenosis undergoing corrective surgery. Preoperative plasma BNP and ANP levels correlated highly with preoperative left ventricular end-systolic wall stress (ESS) (r = 0.96, p < 0.0001 and r = 0.95, p < 0.0001, respectively). Moreover, between preoperative and late postoperative states, the difference of the plasma levels of BNP and ANP correlated with the difference of ESS. In two patients with elevated ESS and quite high preoperative plasma BNP (> 1000 pg/ml), rapid decrease of the plasma level after operation was observed. These results suggest that synthesis and secretion of BNP and ANP are stimulated by the increase of left ventricular end-systolic wall stress in patients with aortic stenosis.

Aged↗