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Biomedical subjects

K Kikuchi

Publications and source records attributed to K Kikuchi.

At least 415 records · Page 23Linked to original sources
PubMed1997

Haplotype analysis of congenital myotonic dystrophy patients from asymptomatic DM father.

We report a family with congenital myotonic dystrophy (CDM) transmitted from an asymptomatic DM father; we analyzed the haplotype of this family by using polymorphism within and by flanking the DM protein kinase locus. One patient with congenital DM was homozygous for all markers studied, except for the expanded CTG repeats. Two other patients with congenital DM were heterozygous. One patient with congenital DM who was homozygous had greater clinical severity and more expanded CTG repeats than other CDM patients who were heterozygous. The asymptomatic father had a DM protomutation.

Child↗
PubMed1997

In vivo anti-tumour effect of 3'-sulphonoquinovosyl 1'-monoacylglyceride isolated from sea urchin (Strongylocentrotus intermedius) intestine.

Extracts from sea urchin intestine were screened for new anti-tumour drugs. Four glycolipids, 3'-sulphonoquinovosyl-1', 2'-diacylglyceride (A-4), 3'-sulphonoquinovosyl-1'-monoacylglyceride (2'-lyso A-4, A-5), NeuGc(alpha)2-6Glc(beta)1-1ceramide (A-6) and HSO3-8NeuGc(alpha)2-6Glc(beta)1-1ceramide (A-7), were isolated from the intestine of sea urchin, Strongylocentrotus intermedius, and characterized by means of proton nuclear magnetic resonance spectroscopy and fast atom bombardment mass spectrometry. When tested for cytotoxic activity against tumour cells in vitro, A-5 showed significant activity, but A-4, -6 and -7 did not. In addition, the hydrophilic derivatives of A-4 or -5 had no cytotoxicity. Furthermore, the anti-tumour effects on nude mice bearing solid tumours of a human lung adenocarcinoma cell line A-549 were evaluated in vivo using A-4 and -5. As a result, A-5 was found to be significantly effective in suppressing the growth of solid tumours, whereas A-4 had no effect. Pathologically, the solid tumours showed haemorrhagic necrosis areas after treatment with A-5. In this study, we have demonstrated the anti-tumour effect of sulphonoquinovosyl-lysoglyceride (A-5), which provides important information that this sulpholipid could be a useful drug for cancer chemotherapy.

Adenocarcinoma↗
PubMed1997

Determination of organophosphorus pesticides in foods using an accelerated solvent extraction system.

Residual organophosphorus pesticides in foods were determined by accelerated solvent extraction (ASE), gel permeation chromatography and GC-FPD. Pesticides were extracted at 100 degrees C under 1500 psi pressure in less than 20 min. Wet samples were extracted after mixing with Extrelut drying agent. Four foods were spiked with 19 pesticides at 0.1 ppm or less. The average recoveries of these pesticides were 80-90% and the precision was < 10%. Both methamidophos and acephate gave 37-50% recoveries and 6-40% precision. These results suggested that ASE can be used to extract residues of organophosphorus pesticides in foods.

Food Analysis↗
PubMed1997

Localization of rat CD1 transcripts and protein in rat tissues--an analysis of rat CD1 expression by in situ hybridization and immunohistochemistry.

CD1 molecules are cell surface glycoproteins non-covalently associated with beta2-microglobulin. Recently, functional features of the CD1 family such as a target ligand and an antigen-presenting structure for T cells have been reported. In the current study, tissue distribution of rat CD1 was analysed by in situ hybridization (ISH) in conjunction with immunohistochemistry to clarify the precise localization of both transcripts and proteins. CD1 transcripts were detected by ISH in a variety of organs: spleen, thymus, liver, lung, heart, kidney, small intestine and skin. In most organs, CD1 immunoreactivity paralleled the amount of CD1 mRNA expression and was localized in the same regions as its gene transcripts. However, there was a clear difference between the level of rat CD1 transcription and protein expression in the small intestine. CD1 mRNA was detected in the enterocytes of crypts of Lieberkuhn, but not in those of the intestinal villi, while immunoreactivity of CD1 protein was observed in the cells of the intestinal villi but not in those of crypts of Lieberkuhn. This suggests that CD1 gene transcription occurs in the enterocytes of intestinal crypts, and that as the cells of intestinal crypts migrate from the crypts to the intestinal villi, CD1 proteins are synthesized and accumulated in the intestinal villi. Such CD1 expression in the enterocytes appears to be consistent with migration-associated differentiation, and suggests that rat CD1 may take part in mucosal immunity as a first line of defence. In addition, clear cell membrane CD1 immunoreactivity on lymphoid cells raises the possibility that intercellular interaction via rat CD1 and T cell receptors may be involved in both lymphoid cell differentiation and immunoregulation.

Animals↗
PubMed1997

V170 area plays an essential role in the biological activity of human ciliary neurotrophic factor.

The structure-function relationships of human ciliary neurotrophic factor (CNTF) were analyzed by mutagenic means. Amino acid substitutions at helix D caused marked changes in the biological activity of CNTF, suggesting that the residues at helix D of CNTF participate in receptor recognition. In particular, both the cell survival-promoting activity and receptor binding ability of V170 mutant CNTF proteins correlated well with the hydrophobicity of amino acids at position 170. The reduction of hydrophobicity at position 170 resulted in a loss of biological activity, indicating that the hydrophobicity of V170 is essential for the receptor binding and cell survival-promoting activity. Substitutions of R171 or D175 evoked very little folding ability and negated the biological activity of CNTF. As R171 and D175 interact electrostatically with each other and with E75 and R72, respectively, these interactions would be indispensable for stabilizing the whole CNTF protein and for maintaining the structure of the receptor binding epitope.

Cell Survival↗
PubMed1997

A wide spectrum of collagen vascular and autoimmune diseases in transgenic rats carrying the env-pX gene of human T lymphocyte virus type I.

To investigate the pathogenesis of human T lymphocyte virus type I (HTLV-I)- related diseases, the env-pX gene of HTLV-I was introduced into the germline of inbred Wistar-King-Aptekman-Hokudai rats. A wide spectrum of collagen vascular diseases was evident in the transgenic rats, including chronic destructive arthritis similar to rheumatoid arthritis, necrotizing arteritis mimicking polyarteritis nodosa, polymyositis, myocarditis, dermatitis, and chronic sialoadenitis and dacryoadenitis resembling Sjögren's syndrome in humans. Thymic atrophy with the depletion of CD4 and CD8 double-positive thymocytes was also observed. In these animals, a number of autoantibodies, including high titers of rheumatoid factor, were present in the serum. We propose that the HTLV-I env-pX gene region may play a pathogenetic role in the development of collagen vascular and autoimmune diseases associated with autoimmune phenomenon.

Animals↗
PubMed1997

Relationships of subunits of type-1 serine/threonine protein phosphatase to morphology and aggregation of B cells.

To elucidate the roles of serine/threonine protein phosphatases PP1 and PP2A in the morphological changes of B-lymphocytes during development and in immune responses, we investigated alterations of protein levels of catalytic subunits of PP1 and PP2A and regulatory subunits of PP1 including M130/M133, inhibitor-1 (I-1) and inhibitor-2 (I-2) in B-cell lines at different maturational stages and during their aggregation induced by phorbol myristate acetate (PMA). The protein levels of PP1delta and/or M130/M133 were significantly lower in B-cell lines without pseudopods, WEHI-231, BAL-17, Daudi, and CESS, than in those with pseudopods, Bcl.1, A20, M12, and SKW6.4, whereas the amounts of PP1alpha and PP2A were similar among them. During aggregation of A20 and CESS cells induced by PMA, an activator of PKC, the amount of PP1delta was progressively decreased, and this decrease was blocked by H7, an inhibitor of PKC. The amount of PP1alpha was constant under these conditions. Okadaic acid, an inhibitor of PP1 and PP2A, also induced aggregation of A20 cells at concentrations sufficient to inhibit PP1, but not at lower concentrations that inhibit PP2A alone. These results suggest that myosin light chain phosphatase composed of PP1delta and M130/M133 is involved in the maintenance and regulation of cytoskeletal structures in B-lymphocytes.

Animals↗
PubMed1997

Alterations in type-1 serine/threonine protein phosphatase PP1alpha in response to B-cell receptor stimulation.

In response to stimulation of B-cells through cell surface IgM, the activity of the serine/threonine protein phosphatase PP1, but not PP2A, was transiently decreased and reached a minimum 10-20 min after the stimulation. The decrease was more profound in the immature B-cell line WEHI-231, than in the mature B-cell line BAL-17. Under these conditions, PP1alpha, an isoform of PP1, showed unique alterations in the patterns of several spots with distinct isoelectic points in the Western blot after two-dimensional electrophoresis, whereas another isoform, PP1delta, did not show any alteration. PP1gamma1 and PP1gamma2 were not detected in B-cells. Similar alterations in these spots were observed in B-cells stimulated by PMA. When partially purified PP1 consisting of PP1alpha and PP1delta was incubated with [gamma-32P]ATP and PKC, radioactive spots of PP1alpha could be detected, but no spot of PP1delta was detected. Because differences in sequence among PP1 isoforms are mostly restricted to their C-terminals, phosphorylation rates of the C-terminal peptides containing the PKC-phosphorylation motif were compared. The C-terminal peptide of PP1alpha is a better substrate for PKC than those of PP1gamma1 and PP1gamma2, and is phosphorylated at the serine residue corresponding to Ser-325 of PP1alpha. The corresponding C-terminal region of PP1delta does not contain the phosphorylation site. On the other hand, there was a large difference in subcellular distribution of PP1delta, but not PP1alpha, between immature and mature B-cells. From these results, it was strongly suggested that PP1alpha is involved, via phosphorylation by PKC, in the regulation of signal transduction in response to the stimulation of B-cells through cell surface IgM.

Amino Acid Sequence↗
PubMed1997

Circulating intercellular adhesion molecule-1 in the sera of patients with systemic sclerosis: enhancement by inflammatory cytokines.

We measured serum levels of circulating intercellular adhesion molecule-1 (cICAM-1) in patients with systemic sclerosis (SSc) and normal controls. The levels of cICAM-1 were determined by sandwich enzyme-linked immunosorbent assay in sera from 88 patients with SSc and in 20 healthy controls. In addition, these levels were examined in the supernatants of cultured peripheral blood mononuclear cells (PBMC) and dermal fibroblasts from 10 patients with SSc and 10 healthy control subjects. Serum levels of cICAM-1 were significantly higher in patients with SSc than in healthy controls. Serum cICAM-1 levels were significantly higher in patients with diffuse cutaneous SSc (dcSSc) than in patients with limited cutaneous SSc (lcSSc). These serum levels were correlated with the presence of contracture of phalanges, pulmonary fibrosis, joint involvement and increased erythrocyte sedimentation rate. The release of cICAM-1 was significantly increased in the supernatants of cultured PBMC from patients with SSc. Moreover, inflammatory cytokines (interferon-gamma, interleukin-1 and tumor necrosis factor-alpha) enhanced the release of cICAM-1 in vitro in SSc cells. These findings suggest that cICAM-1 may be involved in immune reactions in this disease.

Cells, Cultured↗
PubMed1997

Tissue inhibitor of metalloproteinase 1 (TIMP-1) may be an autocrine growth factor in scleroderma fibroblasts.

In scleroderma (systemic sclerosis, SSc), an autoimmune disorder in which excessive extracellular matrix is deposited in skin and internal organs, one of the suggested contributory factors to the development of fibrosis is a decrease in collagenase activity that may be related to levels of serum tissue inhibitors of metalloproteinases 1 (TIMP-1). We recently reported that the serum TIMP-1 levels in SSc patients were elevated compared with normal controls. To determine the biologic significance of TIMP-1 in SSc, we compared the proliferative effects of TIMP-1 between normal and SSc fibroblasts. TIMP-1 showed significant mitogenic activity for both normal and SSc fibroblasts. The mitogenic responses to TIMP-1 (33-100 ng/ml) in SSc fibroblasts, however, were significantly greater than those in normal controls and were completely neutralized in the presence of anti-TIMP-1 IgG. Moreover, anti-TIMP-1 IgG partially but significantly blocked the basal mitogenic activities of SSc fibroblasts. SSc fibroblasts produced increased amounts of TIMP-1 relative to normal fibroblasts, as confirmed by western blotting, ELISA, and RT-PCR techniques. In contrast, transforming growth factor beta1 (TGF-beta1) upregulated TIMP-1 production in normal fibroblasts but not in SSc fibroblasts with elevated spontaneous secretion of TIMP-1. These observations suggest that TIMP-1 may play an important role as an autocrine growth factor in the fibrotic process in SSc.

Female↗
PubMed1997

Papillary tubular adenoma with marked tubular vacuolization.

We report a case of papillary tubular adenoma, arising on the knee joint. The overall histologic structure of the tumor is consistent with that of papillary tubular adenoma with slight interluminal papillary changes, but most of the tumor cells present vacuolization outlined by carcinoembryonic antigen staining, suggesting that this adenoma may have resulted from microlumen formation. This is, to our knowledge, the first reported case of a papillary tubular adenoma with marked tubular vacuolization.

Adenoma, Sweat Gland↗
PubMed1997

Cytotoxicity of histocompatibility leukocyte antigen-DR8-restricted CD4 killer T cells against human autologous squamous cell carcinoma.

Although CD8+ killer T cells reacting against human autologous tumor cells have recently been studied in detail, little is known about the cytotoxic mechanism of CD4+ T cells against such tumor cells. In order to investigate this, we have established CD4+ cytotoxic T lymphocyte TcOSC-20 lines. TcOSC-20 showed selective cytotoxic activity against autologous OSC-20 cells, derived from a cancer of the tongue, in an HLA-DR-restricted fashion. HLA-DR8 (DRB1*08032) is the only DR molecule expressed on OSC-20 cells, and anti-DR8 monoclonal antibody could inhibit the cytotoxicity, suggesting that HLA-DRB1*08032 is the tumor rejection antigen-presenting molecule to TcOSC-20. The Fas ligand was expressed on TcOSC-20 lines, and its expression was induced upon mixed lymphocyte-tumor cell culture of autologous peripheral blood lymphocytes. Furthermore, the cytotoxicity of TcOSC-20 was inhibited by anti-Fas ligand antibody. These data imply that TcOSC-20 lines recognize the tumor antigenic peptide presented by HLA-DR8, and exert cytotoxicity against autologous tumor cells via a Fas-mediated cytotoxic pathway.

Antibodies, Monoclonal↗
PubMed1997

Two distinct human uterine cervical epithelial cell lines established after transfection with human papillomavirus 16 DNA.

We have established two distinct human cervical cell lines, NCC16 and NCE16, after transfecting human papillomavirus type 16 (HPV16) DNA into normal human ecto-cervical and endo-cervical epithelial cells, respectively. Both lines expressed HPV16 E6 and E7 as detected by reverse transcriptase-polymerase chain reaction and northern blot hybridization. These cells have been passaged for over 100 population doublings and express strong telomerase activity. Neither cell line was tumorigenic in athymic nu/nu mice. However, both NCC16 and NCE16 developed abnormally stratified architectures following implantation with a silicon membrane sheet in the back of athymic nude mice. The former cells were pathohistologically similar to carcinoma, while the latter produced Alcian-blue positive cells, suggesting the occurrence of metaplastic changes. These distinct cell lines offer a useful model system for the study of cervical carcinogenesis and of its regulatory mechanism after HPV infection in different regions of the uterine cervix.

Animals↗
PubMed1997

Clinical features of patients with chronic liver disease associated with hepatitis C virus genotype 1a/I in Okinawa, Japan.

The clinical characteristics of chronic hepatitis C virus (HCV) carriers with HCV genotype 1a/I infection were investigated and compared with those of chronic HCV carriers infected with 1b/II, 2a/III, 2b/IV and the mixed type of infection. We found that 16 of 408 (3.9%) carriers had HCV genotype 1a infection, comprising four of 67 (6.0%) blood donors, 11 of 263 (4.2%) patients with chronic hepatitis and one of 39 (2.6%) patients with liver cirrhosis. Three of 408 subjects had a mixed infection of genotypes 1a/I and 1b/II. All carriers with genotype 1a (including those with the mixed infection) were of Japanese origin and all, except one who was born in Brazil, were born in Okinawa Prefecture. Nine of 14 patients infected with genotype 1a for whom medical records were obtained had a history suggestive of infection through blood exposure; six had had blood transfusions, one had tattoos, one is a nurse and one had a history of drug addiction. There were no haemophiliacs or other multitransfused patients in the genotype 1a group. Of 10 patients infected with genotype 1a who received interferon (IFN) therapy, four (40%) showed a complete response. Although the small number of patients infected with genotype 1a in the present study precluded statistical analysis of the response to IFN, the response in patients with genotype 1a was better than the response in those infected with genotype 1b and poorer than the response in those patients infected with genotype 2a/III or 2b/IV.

Adult↗
PubMed1997

Detection of the mutation in facioscapulohumeral muscular dystrophy patients.

The gene responsible for facioscapulohumeral muscular dystrophy (FSHD) was mapped to chromosome 4q35 by linkage analyses. Recently, the probe p13E-11 derived from the cosmid clone 13E, which has been mapped to 4qter, detected a polymorphic EcoRI fragment, usually greater than 28 kb in normal individuals. In sporadic and familial FSHD patients, a specific shorter fragment, usually smaller than 28 kb, was found to cosegregate with FSHD. Two FSHD patients are presented here. Patient 1 is a sporadic case of FSHD with healthy parents. He had a de novo mutation identified by Southern blot analysis using the above-mentioned probe. Patient 2 is a typical familial FSHD patient clinically and histologically. A rearranged and shortened EcoRI fragment was identified by molecular analysis. Southern blot analysis using the probe p13E-11 also indicated a rearranged EcoRI fragment in both patients.

Alleles↗
PubMed1997

Antimicrobial activities of squalamine mimics.

We investigated the antimicrobial properties of compounds with structural features that were designed to mimic those of squalamine, an antibiotic isolated from the stomach of the dogfish shark. The mimics, like squalamine, are sterol-polyamine conjugates. Unlike squalamine, the mimics were simple to prepare, at high yield, from readily available starting materials. Several squalamine mimics showed activity against gram-negative rods, gram-positive cocci including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium, and fungi. Some had little or no hemolytic activity. The hydrophobicity of the sterol backbone and the length and the cationic charge of the side chains appeared to be critical determinants of activity. One of the squalamine mimics, SM-7, was bactericidal against Escherichia coli, Pseudomonas aeruginosa, and S. aureus; its activity was decreased by divalent or monovalent cations and by bovine serum albumin. Subinhibitory concentrations of SM-7 markedly enhanced the antimicrobial activity of rifampin against gram-negative rods. These results suggest that the compounds may disrupt an outer membrane of gram-negative rods. Squalamine mimics are a new class of broad-spectrum antimicrobial agents. The antagonism of their activity by serum and albumin and their hemolytic properties may limit their use as systemic agents. The squalamine mimics, because of their potencies, broad spectra of antimicrobial activity, and potential for systemic toxicity, appear to be good candidates for development as topical antimicrobial agents.

Anti-Bacterial Agents↗
PubMed1997

Prevalence and clinical relevance of 52-kDa and 60-kDa Ro/SS-A autoantibodies in Japanese patients with systemic sclerosis.

OBJECTIVE: To determine the prevalence of 52-Kda and 60-Kda Ro/SS-A autoantibodies in serum samples from Japanese patients with systemic sclerosis (SSc). METHODS: Serum samples from 263 Japanese patients with SSc were examined by double immunodiffusion and enzyme linked immunosorbent assay (ELISA). RESULTS: By double immunodiffusion, 29 serum samples from patients with SSc were found to possess anti-Ro/SS-A antibodies. By ELISA, 31 serum samples were positive for anti-Ro52 and/or anti-Ro60. Of 27 serum samples that were positive by both methods, 15 reacted with both Ro52 and Ro60, five with Ro52 alone, and seven with Ro60 alone. Eleven of 12 patients with both anti-Ro52 and anti-Ro60 and all five patients with anti-Ro52 alone had Sjögren's syndrome, while only one of six patients with anti-Ro60 alone had this disorder. CONCLUSIONS: Anti-Ro52 may be a serological marker for the presence of Sjögren's syndrome in anti-Ro/SS-A-positive patients with SSc.

Antibodies, Antinuclear↗