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1.
Sci Total Environ ; 542(Pt A): 247-53, 2016 Jan 15.
Article in English | MEDLINE | ID: mdl-26519584

ABSTRACT

In many regions of the world, climatic change is associated with increased extreme temperatures, which can have severe effects on mortality and morbidity. In this study, we examine the effect of extreme weather on hospital admissions in Cyprus, for inland and coastal areas, through the use of synoptic weather classifications (air mass types). In addition, the effect of particulate air pollution (PM10) on morbidity is examined. Our results show that two air mass types, namely (a) warm, rainy days with increased levels of water vapour in the atmosphere and (b) cold, cloudy days with increased levels of precipitation, were associated with increased morbidity in the form of hospital admissions. This was true both for cardiovascular and respiratory conditions, for all age groups, but particularly for the elderly, aged over 65. Particulate air pollution was also associated with increased morbidity in Cyprus, where the effect was more pronounced for cardiovascular diseases.


Subject(s)
Air Pollution/statistics & numerical data , Cardiovascular Diseases/epidemiology , Environmental Exposure/statistics & numerical data , Hospitalization/statistics & numerical data , Respiratory Tract Diseases/epidemiology , Weather , Cyprus/epidemiology , Humans , Particulate Matter/analysis
2.
Arq. bras. med. vet. zootec ; 65(3): 645-648, June 2013. ilus
Article in Portuguese | LILACS | ID: lil-679092

ABSTRACT

Descreve-se o primeiro caso de granuloma leproide canino na região amazônica, Brasil, em um canino da raça Boxer, procedente do município de Castanhal, Pará, que apresentava lesões nodulares, alopécicas, firmes, ulceradas e não pruriginosas nas duas pinas. Os nódulos foram retirados cirurgicamente e enviados para análise histopatológica. O exame microscópico revelou marcada infiltração inflamatória constituída por macrófagos, plasmócitos, neutrófilos, linfócitos e células gigantes. A técnica de Ziehl-Neelsen evidenciou grande quantidade de bacilos álcool-ácido resistentes no interior de macrófagos e de células gigantes. Houve forte reatividade ao exame imuno-histoquímico para Mycobacterium spp.


This study describes the first case of canine leproid granuloma in the Amazon region, Brazil. A Boxer dog from the city of Castanhal, Pará presented nodular, alopecic, firm, ulcerated, non-pruritic lesions on both pinnae. The nodules were removed surgically and submitted to histopathological analysis. The microscopic exam revealed marked inflammatory infiltrate composed of macrophages, plasma cells, neutrophils, lymphocytes and giant cells. The Ziehl-Neelsen staining technique showed a large amount of alcohol-acid resistant bacilli inside macrophages and giant cells. The samples exhibited a strong immunohistochemical reaction to Mycobacterium spp.


Subject(s)
Amazonian Ecosystem/analysis , Granuloma/pathology , Microscopy , Dogs
3.
Br J Dermatol ; 149(1): 30-8, 2003 Jul.
Article in English | MEDLINE | ID: mdl-12890192

ABSTRACT

BACKGROUND: The mechanism by which a low dose of methotrexate (MTX) works to treat psoriasis is not clear. The overexpression of cell adhesion molecules on dermal vessels is important in the pathogenesis of psoriasis and is probably induced by upregulation of tumour necrosis factor (TNF)-alpha. OBJECTIVES: To determine the effects of MTX at concentrations comparable with in vivo levels after the administration of low-dose MTX to human umbilical vein endothelial cells (HUVEC) on the growth and expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). METHODS: Cell proliferation assay, immunostaining, immunoblotting, cell enzyme-linked immunosorbent assay and reverse transcriptase-polymerase chain reaction (RT-PCR) were performed to examine the effects of MTX on HUVEC. RESULTS: MTX inhibited the proliferation of HUVEC at 10-7 mol L-1 and 10-6 mol L-1 without showing cytotoxic effects. It also inhibited TNF-alpha-induced ICAM-1 and VCAM-1 expression by HUVEC at 10-6 mol L-1. The inhibitory effect of MTX was more pronounced on ICAM-1 expression than on VCAM-1 expression. RT-PCR analysis revealed that TNF-alpha-induced ICAM-1 gene expression was strongly downregulated by MTX. CONCLUSIONS: Low-dose MTX may act on psoriasis by suppressing the TNF-alpha-induced expression of ICAM-1 and VCAM-1 by vascular endothelial cells. Inhibition of neovascularization may be another mechanism of action of MTX.


Subject(s)
Endothelium, Vascular/drug effects , Immunosuppressive Agents/pharmacology , Intercellular Adhesion Molecule-1/metabolism , Methotrexate/pharmacology , Vascular Cell Adhesion Molecule-1/metabolism , Blotting, Western , Cell Division/drug effects , Cells, Cultured , Dose-Response Relationship, Drug , Down-Regulation/drug effects , Endothelium, Vascular/cytology , Endothelium, Vascular/metabolism , Humans , Intercellular Adhesion Molecule-1/genetics , Reverse Transcriptase Polymerase Chain Reaction , Tumor Necrosis Factor-alpha/pharmacology
4.
Brain Res ; 925(1): 89-99, 2002 Jan 18.
Article in English | MEDLINE | ID: mdl-11755903

ABSTRACT

The mechanism of control of GAD expression by GABA and excitatory amino acids (EAAs) was studied in chick and rat retina cultures using immunohistochemical and PAGE-immunoblot detection of the enzyme, as well as by measuring enzyme activity. Aggregate cultures were prepared with retina cells obtained from chick embryos at embryonic days 8-9 (E8-E9). Organotypical cultures were also prepared with retinas from E14 chick embryos, post-hatched chicken and P21 rats. GABA (1-20 mM) fully prevented GAD expression in aggregate and organotypical cultures from chick embryo retinas. A substantial, but not complete, reduction of GAD was also observed in organotypical cultures of post-hatched chicken and P21 rats, in which both forms of the enzyme (GAD65 and 67) were affected. The GABA effect was not mimicked by THIP (100 microM), baclofen (100 microM) or CACA (300 microM), agonists of GABAa, b and c receptors, respectively. NNC-711, a potent inhibitor of GABA transporters, reduced by 50% the inhibition of GAD activity promoted by GABA. Aggregates exposed to GABA and treated with glutamate (5 mM) or kainate (100 microM) displayed an intense GAD-like immunoreactivity in many cell bodies, but not in neurite regions. Immunoblot analysis revealed that the increase in GAD-like immunoreactivity by EAA corresponded to a 67-kDa protein. However, GAD activity was not detected. Treatment of aggregates or retina homogenates with SNAP, a NO producing agent (but not its oxidized form), reduced GAD activity by more than 60% indicating that the lack of enzyme activity in GAD-like immunoreactive cells, could be due to NO production by EAA stimulation.


Subject(s)
Cytarabine/analogs & derivatives , Glutamate Decarboxylase/metabolism , Glutamic Acid/pharmacology , Retina/metabolism , gamma-Aminobutyric Acid/pharmacology , Animals , Baclofen/pharmacology , Cells, Cultured , Chick Embryo , Cytarabine/pharmacology , Excitatory Amino Acid Agonists/pharmacology , GABA Agonists/pharmacology , Glutamate Decarboxylase/analysis , Immunohistochemistry , Isoxazoles/pharmacology , Kainic Acid/pharmacology , Nitric Oxide/metabolism , Retina/cytology , Retina/drug effects
5.
Mod Rheumatol ; 12(2): 190-4, 2002 Jun.
Article in English | MEDLINE | ID: mdl-24383911

ABSTRACT

Abstract We present a rare case of simultaneous muscle weakness and cutaneous depigmentation. Muscle and skin biopsies confirmed the diagnosis of polymyositis and generalized vitiligo vulgaris. All symptoms improved after steroid therapy. Immunohistochemical analyses revealed predominant CD8-positive T cell infiltration in both muscular and cutaneous lesions. This case suggests that a common autoimmune mechanism mediated by cytotoxic T lymphocytes underlies the pathogeneses of these two diseases.

6.
J Biol Chem ; 276(48): 44488-94, 2001 Nov 30.
Article in English | MEDLINE | ID: mdl-11577077

ABSTRACT

Antineoplastic bis(dioxopiperazine)s, such as meso-2,3-bis(2,6-dioxopiperazin-4-yl)butane (ICRF-193), are widely believed to be only catalytic inhibitors of topoisomerase II. However, topoisomerase inhibitors have little or no antineoplastic activity unless they are topoisomerase poisons, a special subclass of topoisomerase-targeting drugs that stabilize topoisomerase-DNA strand passing intermediates and thus cause the topoisomerase to become a cytotoxic DNA-damaging agent. Here we report that ICRF-193 is a very significant topoisomerase II poison. Detection of topoisomerase II poisoning by ICRF-193 required the use of a chaotropic protein denaturant in the topoisomerase poisoning assays. ICRF-193 caused dose-dependent cross-linking of human topoisomerase IIbeta to DNA and stimulated topoisomerase IIbeta-mediated DNA cleavage at specific sites on (32)P-end-labeled DNA. Human topoisomerase IIalpha-mediated DNA cleavage was stimulated to a lesser extent by ICRF-193. In vivo experiments with MCF-7 cells also showed the requirement of a chaotropic protein denaturant in the assays and selectivity for the beta-isozyme of human topoisomerase II. Studies with two topoisomerase IIbeta-negative cell model systems confirmed significant topoisomerase II poisoning by ICRF-193 in the wild type cells and were consistent with beta-isozyme selectivity. Common use of only the detergent, SDS, in assays may have led to failure to detect topoisomerase II poisoning by ICRF-193 in earlier studies.


Subject(s)
DNA Topoisomerases, Type II/metabolism , Enzyme Inhibitors/pharmacology , Piperazines/pharmacology , Topoisomerase II Inhibitors , Base Sequence , Blotting, Western , Catalysis , Cell Nucleus/enzymology , Diketopiperazines , Dose-Response Relationship, Drug , Humans , Molecular Sequence Data , Substrate Specificity , Time Factors , Tumor Cells, Cultured
7.
J Biochem ; 130(4): 497-502, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11574069

ABSTRACT

Mitochondrial processing peptidase (MPP) specifically cleaves off the N-terminal presequence of the mitochondrial protein precursor. Previous studies demonstrated that Arg at position -2 from the cleavage site, which is found among many precursors, plays a critical role in recognition by MPP. We analyzed the structural elements of bovine cytochrome P450 side-chain cleavage enzyme precursor [pre-P450(SCC)], which has Ala at position -2, for recognition by MPP. Replacement of Ala position -2 of pre-P450(SCC) with Arg resulted in an increase in the cleavage rate. Replacement with Gly caused a reduction in the cleavage rate and the appearance of an additional cleavage site downstream of the authentic site. A pre-P450(SCC) mutant with Met at position -2 retained cleavage efficiency equal to that of the wild type. These results indicate that -2 Ala of pre-P450(SCC) is recognized by MPP as a determinant for precise cleavage, and that the amino acid at -2 is required to have a straight methylene chain for interaction with the S(2) site. The preference for distal basic residues, a hydrophobic residue at +1, and hydroxyl residues at +2 and +3, was almost the same as those of the precursors with Arg at -2, indicating that the recognition mechanism of pre-P450(SCC) by MPP is essentially the same as that of the precursors with Arg at position -2.


Subject(s)
Arginine/metabolism , Cholesterol Side-Chain Cleavage Enzyme/chemistry , Cholesterol Side-Chain Cleavage Enzyme/metabolism , Enzyme Precursors/chemistry , Enzyme Precursors/metabolism , Metalloendopeptidases/metabolism , Amino Acid Motifs , Amino Acid Sequence , Amino Acid Substitution , Animals , Arginine/genetics , Binding Sites , Catalytic Domain , Cattle , Cholesterol Side-Chain Cleavage Enzyme/genetics , Enzyme Precursors/genetics , Kinetics , Metalloendopeptidases/chemistry , Mitochondria/metabolism , Molecular Sequence Data , Mutation , Protein Processing, Post-Translational , Sequence Alignment , Structure-Activity Relationship , Substrate Specificity , Mitochondrial Processing Peptidase
8.
Br J Cancer ; 84(7): 886-91, 2001 Apr 06.
Article in English | MEDLINE | ID: mdl-11286466

ABSTRACT

Chemotherapy is not effective for hepatocellular carcinoma (HCC). HMG-CoA redutase inhibitors have cytostatic activity for cancer cells, but their clinical usefulness is unknown. To investigate whether pravastatin, a potent HMG-CoA reductase inhibitor, prolongs survival in patients with advanced HCC, this randomized controlled trial was conducted between February 1990 and February 1998 at Osaka University Hospital. 91 consecutive patients <71 years old (mean age 62) with unresectable HCC were enroled in this study. 8 patients were withdrawn because of progressive liver dysfunction; 83 patients were randomized to standard treatment with or without pravastatin. All patients underwent transcatheter arterial embolization (TAE) followed by oral 5-FU 200 mg(-1)d for 2 months. Patients were then randomly assigned to control (n = 42) and pravastatin (n = 41) groups. Pravastatin was administered at a daily dose of 40 mg. The effect of pravastatin on tumour growth was assessed by ultrasonography. Primary endpoint was death due to progression of HCC. The duration of pravastatin administration was 16.5 +/- 9.8 months (mean +/- SD). No patients in either group were lost to follow-up. Median survival was 18 months in the pravastatin group versus 9 months in controls (P = 0.006). The Cox proportional hazards model showed that pravastatin was a significant factor contributing to survival. Pravastatin prolonged the survival of patients with advanced HCC, suggesting its value for adjuvant treatment.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Hepatocellular/drug therapy , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Liver Neoplasms/drug therapy , Pravastatin/therapeutic use , Adult , Aged , Alanine Transaminase/blood , Antimetabolites, Antineoplastic/administration & dosage , Antimetabolites, Antineoplastic/therapeutic use , Bilirubin/blood , Carcinoma, Hepatocellular/blood , Carcinoma, Hepatocellular/therapy , Drug Administration Schedule , Embolization, Therapeutic/methods , Female , Fluorouracil/administration & dosage , Fluorouracil/therapeutic use , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/administration & dosage , Liver Neoplasms/blood , Liver Neoplasms/therapy , Male , Middle Aged , Pravastatin/administration & dosage , alpha-Fetoproteins/metabolism
9.
Cancer Res ; 60(21): 5937-40, 2000 Nov 01.
Article in English | MEDLINE | ID: mdl-11085507

ABSTRACT

Chloroquinoxaline sulfonamide (chlorosulfaquinoxaline, CQS, NSC 339004) is active against murine and human solid tumors. On the basis of its structural similarity to the topoisomerase IIbeta-specific drug XK469, CQS was tested and found to be both a topoisomerase-IIalpha and a topoisomerase-IIbeta poison. Topoisomerase II poisoning by CQS is essentially undetectable in assays using the common protein denaturant SDS, but easily detectable with strong chaotropic protein denaturants. The finding that detection of topoisomerase poisoning can be so dependent on the protein denaturant used in the assay has implications for drug discovery efforts and for our understanding of topoisomerase poisons.


Subject(s)
Antineoplastic Agents/pharmacology , DNA Topoisomerases, Type II , Enzyme Inhibitors/pharmacology , Isoenzymes/antagonists & inhibitors , Quinoxalines/pharmacology , Sulfanilamides/pharmacology , Topoisomerase II Inhibitors , Animals , Antigens, Neoplasm , Cell Line , DNA/metabolism , DNA-Binding Proteins , Dose-Response Relationship, Drug , Guanidine/pharmacology , Kidney/cytology , Kidney/drug effects , Kidney/enzymology , Protein Denaturation
10.
JBP, j. bras. odontopediatr. odontol. bebê ; 2(10): 479-485, nov.-dez. 1999. ilus, CD-ROM
Article in Portuguese | LILACS, BBO - Dentistry | ID: biblio-851956

ABSTRACT

A displasia fibrosa monostótica é uma doença que acomete principalmente crianças e adolescentes. Este trabalho tem por objetivo discutir os aspectos clínicos e radiográficos, bem como alternativas de tratamento desta enfermidade, a fim de alertar os cirurgiões-dentistas quanto à precocidade do diagnóstico no paciente infantil. Os autores apresentam um caso de displasia fibrosa monostótica em uma criança de 11 anos, que foi tratada por meio de cirurgia conservadora


Subject(s)
Humans , Male , Child , General Surgery
11.
Proc Natl Acad Sci U S A ; 96(21): 12168-73, 1999 Oct 12.
Article in English | MEDLINE | ID: mdl-10518594

ABSTRACT

XK469 (NSC 697887) is a synthetic quinoxaline phenoxypropionic acid derivative that possesses unusual solid tumor selectivity and activity against multidrug-resistant cancer cells. We report here that XK469 and its S(-) and R(+)-isomers induce reversible protein-DNA crosslinks in mammalian cells. Under protein denaturing conditions, the protein-DNA crosslinks are rendered irreversible and stable to DNA banding by CsCl gradient ultracentrifugation. Several lines of evidence indicate that the primary target of XK469 is topoisomerase IIbeta. Preferential targeting of topoisomerase IIbeta may explain the solid tumor selectivity of XK469 and its analogs because solid tumors, unlike leukemias, often have large populations of cells in the G(1)/G(0) phases of the cell cycle in which topoisomerase IIbeta is high whereas topoisomerase IIalpha, the primary target of many leukemia selective drugs, is low.


Subject(s)
Antineoplastic Agents/pharmacology , DNA Topoisomerases, Type II/metabolism , DNA/drug effects , Quinoxalines/pharmacology , Animals , Antigens, Neoplasm , Antineoplastic Agents/chemistry , Blotting, Western , Cell Cycle/physiology , Cell Line , Centrifugation, Density Gradient , Chlorocebus aethiops , Cross-Linking Reagents/metabolism , DNA-Binding Proteins/chemistry , Dose-Response Relationship, Drug , Drug Design , Fibroblasts/drug effects , Humans , Isoenzymes/metabolism , Quinoxalines/chemistry , Substrate Specificity
12.
Virology ; 262(2): 457-69, 1999 Sep 30.
Article in English | MEDLINE | ID: mdl-10502524

ABSTRACT

Episomal SV40 (SV40: simian virus 40, Polyomavirus maccacae) has been reported in SV40-transformed human fibroblast cell lines the integrated SV40 sequences of which are unlikely to give rise to episomal copies by recombinational mechanisms. The levels of episomal viral DNA in these lines are high, being easily visualized by ethidium staining of agarose gels after electrophoresis. We find that the episomal mutant gmSV40 in GM637 cells represents a persistent lytic infection that can be cured by treatment with neutralizing antibody, leaving only the chromosomally integrated viral genomes. The finding that maintenance of the gmSV40 in GM637 cells is due to persistent infection raises a note of caution for SV40-transformed lines with episomal SV40 genomes because these lines often are used in studies of DNA replication and repair. An infective center assay that does not depend on plaque formation shows that gmSV40 is a host range mutant, with poor infectivity for CV-1 monkey kidney cells and greatly increased infectivity for human cells. Passage of gmSV40 through monkey kidney cells selects for variants with greatly increased infectivity for monkey cells and, independently, for cytopathic variants that produce plaques. Thus plaque assays can give very unreliable infective center values in studies of host range mutants.


Subject(s)
DNA, Viral/analysis , Genome, Viral , Plasmids , Simian virus 40/genetics , Simian virus 40/physiology , Animals , Antibodies, Viral/immunology , Antigens, Polyomavirus Transforming/genetics , Antigens, Polyomavirus Transforming/physiology , Cell Line , Cell Transformation, Viral , Cloning, Molecular , Cytopathogenic Effect, Viral , DNA Replication/drug effects , DNA, Viral/genetics , Fibroblasts , Haplorhini , Humans , Neutralization Tests , Proviruses/genetics , Sequence Deletion , Simian virus 40/immunology , Simian virus 40/isolation & purification , Virus Integration/genetics , Virus Replication/drug effects , Virus Replication/genetics
13.
Metabolism ; 48(9): 1136-40, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10484053

ABSTRACT

Lysinuric protein intolerance (LPI) results in low serum L-arginine, hyperammonemia, mental retardation, thrombocytopenia, and an increased frequency of bowel movements. Our objective was to evaluate the effects of low serum L-arginine, the essential substrate for reactions catalyzed by nitric oxide synthetase (NOS), on the serum nitric oxide (NO) level and coagulation activity in a patient with LPI. A 37-year-old Japanese man who presented with abdominal pain and subnormal fasting levels of serum L-arginine and L-lysine was found to have LPI. The result of oral administration of diamino acids was an increased in urine and a decrease in serum, thus confirming the diagnosis. A decrease in the platelet count and an increase in the plasma levels of thrombin-antithrombin III complex (TAT) and fibrin degradation products (FDPs) indicated the presence of subclinical intravascular coagulation. Serum levels of NO derivatives and L-arginine were determined after intravenous administration of L-arginine. The effects of intravenous L-arginine or transdermal nitroglycerin on the plasma level of TAT were also investigated. Serum levels of NO derivatives were significantly reduced in the LPI patient versus the healthy control group (n = 5). Intravenous administration of L-arginine increased the serum level of NO derivatives and the platelet count and reduced plasma TAT and FDP levels. The plasma level of TAT was also reduced by transdermal nitroglycerin. A decrease in the serum level of L-arginine in patients with LPI appears to result in a decrease in NO production. The improvement in plasma TAT levels produced by administration of intravenous L-arginine or transdermal nitroglycerin suggests that intravascular coagulation is exacerbated by the decrease of NO production in patients with LPI.


Subject(s)
Amino Acid Metabolism, Inborn Errors/blood , Arginine/blood , Blood Coagulation Disorders/blood , Lysine/urine , Nitric Oxide/blood , Adult , Amino Acid Metabolism, Inborn Errors/pathology , Antithrombin III , Arginine/pharmacology , Arginine/urine , Blood Coagulation Disorders/pathology , Citrulline/blood , Cyclic GMP/blood , Humans , Lysine/blood , Male , Nitroglycerin/pharmacology , Ornithine/blood , Ornithine/urine , Peptide Hydrolases , Platelet Aggregation/drug effects , Thrombosis/pathology
14.
Int J Dev Neurosci ; 17(3): 201-13, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10452364

ABSTRACT

In the present work, we have characterized the maturation of the GABAergic system in mammalian retina. Immunoreactivity for GABA, GAD (glutamic acid decarboxylase, EC 4.1.1.15) -65 and -67 in the adult rat retina was localized in cells in the inner nuclear and ganglion cell layers. This pattern was established around postnatal day 8 and included transient GABA and GAD-67 expression in horizontal cells. GAD activity was very low at P1 and P4, increasing after P8, reaching maximal activity by P21 and decreasing to attain adult values by P30. GABA content was approximately constant from P1 to P13, increasing thereafter to reach adult levels. GAD protein content increased progressively with postnatal development and the two isoforms could be distinguished at P8. The disparity between retinal GABA content vs. presence and activity of the synthesizing enzyme, led us to investigate the alternative pathway for GABA synthesis that utilizes putrescine as a substrate. Highest levels of ornithine decarboxylase activity (the limiting step for putrescine synthesis) were found between P1 and P4, decreasing to very low levels after P13. The same pattern was observed for putrescine content in the retina. Highest amounts were found at P1, that decreased and remained constant after P13. Additionally, approximately 40% of tritiated putrescine incorporated by P1, P4 and adult retinas was converted into GABA. Our results suggest the existence of two different sources of GABA in mammalian retina, one that uses glutamate as a precursor and predominates in the mature nervous system and another that utilizes putrescine and is present transiently at early developmental stages.


Subject(s)
Glutamate Decarboxylase/analysis , Isoenzymes/analysis , Retina/chemistry , gamma-Aminobutyric Acid/analysis , Animals , Animals, Newborn , Immunoblotting , Immunohistochemistry , Ornithine Decarboxylase/metabolism , Putrescine/metabolism , Rats , Retina/growth & development
15.
Int J Cancer ; 80(1): 126-33, 1999 Jan 05.
Article in English | MEDLINE | ID: mdl-9935242

ABSTRACT

A series of studies using farnesyltransferase (FTase) inhibitors that the inhibition of FTase function suppresses the growth of ras-transformed cells in vitro and in vivo. However, whether FTase is directly involved in the regulation of cell proliferation remains to be demonstrated. To investigate whether overexpression of FTase results in altered cell growth and transformation, we thus used NIH3T3 cells transfected with cDNA constructs of both alpha and beta subunits of human FTase. FTase-overexpressing cells resulted in a 3- to 13-fold increase in the expression of the alpha and beta subunit protein of FTase and a 1.5- to 3-fold increase in the level of the enzyme activity compared with untransfected NIH3T3 cells or vector-transfected cells. Further investigations using metabolic labeling indicated that farnesylation of Ras was enhanced in FTase-overexpressing cells. Insulin-like growth factor-I, platelet-derived growth factor (PDGF), and basic fibroblast growth factor (bFGF) more potently enhanced DNA synthesis and anchorage-dependent growth in FTase-overexpressing cells than in control cells, in a dose-dependent manner. In particular, PDGF and bFGF also induced dose-dependently enhanced colony formation in soft agar in FTase-overexpressing cells. Furthermore, in FTase-transfectants, bFGF stimulated high activation of mitogen-activated protein kinase. Interestingly, FTase-transfectants developed progressive tumors in nude mice. Light and electron microscopy showed that the tumors were characteristic of fibrosarcoma, which were distinct from v-ras-induced tumors. Overexpression of FTase in NIH3T3 cells thus amplifies growth-factor-mediated cell growth and transformation, and FTase-overexpressing cells form tumors in nude mice.


Subject(s)
Alkyl and Aryl Transferases/genetics , Alkyl and Aryl Transferases/metabolism , Cell Transformation, Neoplastic , 3T3 Cells , Animals , Calcium-Calmodulin-Dependent Protein Kinases/metabolism , Cell Division , DNA Replication , Farnesyltranstransferase , Female , Fibroblast Growth Factor 2/pharmacology , Humans , Macromolecular Substances , Mice , Mice, Nude , Neoplasms, Experimental/enzymology , Neoplasms, Experimental/pathology , Protein Prenylation , Proto-Oncogene Proteins c-raf/metabolism , Recombinant Proteins/metabolism , Transfection
16.
Neuroscience ; 85(2): 627-36, 1998 Jul.
Article in English | MEDLINE | ID: mdl-9622258

ABSTRACT

We produced the monoclonal antibody RT10F7, characterized its antigenic specificity and expression in the adult and developing retina, in cultured retinal cells and in other parts of the central nervous system. In metabolically-labelled retinal cultures RT10F7 immunoprecipitated a protein of approximately 36,000 mol. wt. In the adult, RT10F7 stained endfeet of Müller cells in the ganglion cell layer, four horizontal bands in the inner plexiform layer, and radial fibres in the outer plexiform layer which terminated at the outer limiting membrane. In the inner nuclear layer, most somata were underlined by Müller processes that wrapped around them, but some cell bodies were immunoreactive for RT10F7 in the cytoplasm. During development, postnatal day 21 was the first age at which the adult pattern of immunoreactivity was present, although a fourth band in the inner plexiform layer was less clear than for the adult. By 14 and eight days after birth, the pattern of RT10F7 immunoreactivity approximated that of the adult; however, only three bands and one band were present, respectively, in the inner plexiform layer. At earlier ages, postnatal days 4, 1 and embryonic ages 19 and 15, the monoclonal antibody stained Müller cell endfeet and radial fibres, from the inner plexiform layer through the neuroblastic layer to the outer limiting membrane. At these ages, the immunoreactivity was more prominent at the level of Müller cell endfeet. The monoclonal antibody stained glia in preparations of dissociated retinal cells maintained in culture but not astrocytes or oligodendrocytes from optic nerve cultures. In brain sections, tanycytes exhibited RT10F7 immunoreactivity. The monoclonal antibody RT10F7 recognized a specific cell type in the retina, the Müller cell. In the adult and developing retina, RT10F7 recognized an antigen that is present primarily in Müller cell processes. This feature allowed us to follow the maturation of the Müller cell and correlate it with developmental events in the retina. RT10F7 is a specific marker for Müller cells in vivo and in vitro and may be useful for studies of function of Müller cells after ablation or after injuries that are known to activate Müller cells.


Subject(s)
Antibodies, Monoclonal/chemistry , Neuroglia/chemistry , Neuroglia/cytology , Retina/chemistry , Retina/cytology , Animals , Antibodies, Monoclonal/metabolism , Antibody Specificity , Antigens/biosynthesis , Antigens/chemistry , Antigens/immunology , Cell Differentiation , Cell Division , Immunohistochemistry , Neuroglia/immunology , Rats , Rats, Long-Evans , Retina/immunology
17.
Eur J Neurosci ; 9(9): 1885-90, 1997 Sep.
Article in English | MEDLINE | ID: mdl-9383211

ABSTRACT

We have looked at the phenotypic expression of gamma-aminobutyric acid (GABA) and the two isoforms of its synthetic enzyme [glutamic acid decarboxylase (GAD)-65 and -67] in adult rat retinas that had the superior colliculus, pretectum and optic tract lesioned unilaterally at birth. It has been shown previously that this type of manipulation induces retrograde degeneration of retinal ganglion cells presumably without affecting other intraretinal neurons. We present evidence that GABAergic amacrine cells are affected by such manipulation. The number of cells immunoreactive for GABA, GAD-65 and GAD-67 decreased in the inner nuclear layer. In the retinal ganglion cell layer, however, the number of GABA- and GAD-65-labelled cells increased, while the number of GAD-67-labelled cells did not change. Biochemical assay showed that overall GAD activity was not altered in retinas of lesioned animals. Our results support the notion that, while neonatal lesion reorganizes the expression of GABA and GAD in the retina, enzyme activity is maintained within normal levels.


Subject(s)
Glutamate Decarboxylase/metabolism , Retinal Ganglion Cells/metabolism , gamma-Aminobutyric Acid/metabolism , Animals , Cell Count , Immunohistochemistry , Phenotype , Rats
18.
J Gastroenterol ; 32(1): 56-62, 1997 Feb.
Article in English | MEDLINE | ID: mdl-9058296

ABSTRACT

The efficacy of interferon-alpha therapy in the treatment of chronic hepatitis C is still limited. A combination therapy of interferon-alpha with ursodeoxycholic acid (UDCA) was tested for its efficacy in the treatment of chronic hepatitis C by a randomized controlled study. Eighty consecutive Japanese patients with chronic hepatitis C were randomly divided into two groups: one group was treated with interferon-alpha (group A, n = 40) and the other with a combination of interferon-alpha and UDCA (group B, n = 40). In both groups, human interferon-alpha (6 million units per day) was intramuscularly injected daily for 2 weeks and then three times a week for 22 weeks: this 24-week period was followed by 24 weeks of observation. In group B, UDCA was also administered, daily at a dose of 600 mg orally, from the beginning of the interferon therapy and administration was continued for 48 weeks. The rates for ALT normalization and clearance of hepatitis C virus (HCV) viremia at the end of the 24-week interferon therapy were similar for groups A and B (58% vs 60% and 55% vs 48%, respectively). At the end of the 24-week follow-up, the sustained normalization rates for ALT levels for the two groups were not different (35% vs 43%), while the rate of clearance was higher in group B (40%) than in group A (23%), but the difference was not significant (P = 0.14). The sustained complete response, i.e., HCV RNA negativity at the end of the follow-up, as well as the maintenance of ALT normalization during the follow-up period, was more frequent in group B (38%) than in group A (18%) although the difference was not significant (P = 0.08). The rate of HCV reactivation after interferon was discontinued was significantly lower in group B (16%) than in group A (59%) (P < 0.01). Although this combination therapy did not lead to a sufficiently sustained complete response, it could serve as adjuvant antiviral therapy when a suitable dosage and administration period are determined.


Subject(s)
Hepatitis C/therapy , Interferon-alpha/administration & dosage , Ursodeoxycholic Acid/administration & dosage , Administration, Oral , Alanine Transaminase/blood , Drug Therapy, Combination , Female , Hepacivirus/genetics , Hepatitis C/virology , Hepatitis, Chronic/therapy , Humans , Injections, Intramuscular , Leukocyte Count , Male , Middle Aged , Platelet Count , RNA, Messenger/blood
19.
Br J Cancer ; 76(8): 1001-10, 1997.
Article in English | MEDLINE | ID: mdl-9376258

ABSTRACT

Recently, many inhibitors of farnesyl protein transferase (FPTase) have been identified. Some of them interrupt cell growth in addition to Ras and nuclear lamin processing of Ras-transformed cells. We have tested the effect of the FPTase inhibitors manumycin, an analogue of farnesyl diphosphate, and KT7595, a gliotoxin derivative, on Ras farnesylation, DNA synthesis and the anchorage-dependent and -independent growth of human colon carcinoma (LoVo), hepatoma (Mahlavu and PLC/PRF/5) and gastric carcinoma (KATO III). Both drugs severely inhibited DNA synthesis, cellular proliferation and Ras farnesylation in LoVo and moderately reduced them in Mahlavu and PLC/PRF/5 but not in KATO III. Complete sequencing of ras genes, however, revealed that LoVo and KATO III have activated Ki-ras and activated N-ras, respectively, whereas Mahlavu and PLC/PRF/5 have no activated ras. We next checked whether the inhibition of the cellular proliferation is due to the blocking of nuclear lamin function. Neither drug disturbed lamin farnesylation and localization, as demonstrated using metabolic labelling, immunoblotting and indirect immunofluorescence. These results indicate that manumycin and KT7595 can inhibit Ras farnesylation and cell growth without disturbing the farnesylation and localization of the lamins on human tumour cell lines.


Subject(s)
Enzyme Inhibitors/pharmacology , Gliotoxin/analogs & derivatives , Neoplasms/drug therapy , Neoplasms/metabolism , Nuclear Proteins/metabolism , Polyenes/pharmacology , Protein Prenylation/drug effects , ras Proteins/metabolism , Alkyl and Aryl Transferases/antagonists & inhibitors , Carcinoma, Hepatocellular/drug therapy , Carcinoma, Hepatocellular/metabolism , Cell Division/drug effects , Colonic Neoplasms/drug therapy , Colonic Neoplasms/metabolism , Colonic Neoplasms/pathology , DNA, Neoplasm/biosynthesis , Drug Screening Assays, Antitumor , Fluorescent Antibody Technique, Indirect , Gliotoxin/pharmacology , Humans , Immunoblotting , Lamins , Liver Neoplasms/drug therapy , Liver Neoplasms/metabolism , Neoplasms/pathology , Nuclear Proteins/genetics , Polyunsaturated Alkamides , Stomach Neoplasms/drug therapy , Stomach Neoplasms/metabolism , Tumor Cells, Cultured , ras Proteins/antagonists & inhibitors
20.
Intern Med ; 36(1): 53-5, 1997 Jan.
Article in English | MEDLINE | ID: mdl-9058102

ABSTRACT

We report a patient with chronic inflammatory demyelinating polyneuropathy (CIDP) accompanied by hepatocellular carcinoma (HCC). Due to the remarkable weakness in the lower limbs and loss of the position sense, he could not walk. On neurophysiological examination, he had impaired nerve conduction velocities. Biopsied nerve and muscle specimens demonstrated demyelination of nerve fibers and neurogenic degeneration of muscles. After steroid therapy he showed marked improvement in muscle strength and sensory function.


Subject(s)
Carcinoma, Hepatocellular/complications , Demyelinating Diseases/etiology , Liver Neoplasms/complications , Paraneoplastic Syndromes/etiology , Polyneuropathies/etiology , Anti-Inflammatory Agents/administration & dosage , Demyelinating Diseases/drug therapy , Demyelinating Diseases/physiopathology , Humans , Male , Methylprednisolone/administration & dosage , Middle Aged , Neural Conduction/drug effects , Paraneoplastic Syndromes/drug therapy , Paraneoplastic Syndromes/physiopathology , Polyneuropathies/drug therapy , Polyneuropathies/physiopathology
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