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1.
Hepatology ; 33(2): 455-63, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11172349

RESUMO

Persons with non-A, non-B hepatitis (cases) identified in 5 transfusion studies in the early 1970s have been followed ever since and compared for outcome with matched, transfused, non-hepatitis controls from the same studies. Previously, we reported no difference in all-cause mortality but slightly increased liver-related mortality between these cohorts after 18 years follow-up. We now present mortality and morbidity data after approximately 25 years of follow-up, restricted to the 3 studies with archived original sera. All-cause mortality was 67% among 222 hepatitis C-related cases and 65% among 377 controls (P = NS). Liver-related mortality was 4.1% and 1.3%, respectively (P =.05). Of 129 living persons with previously diagnosed transfusion-associated hepatitis (TAH), 90 (70%) had proven TAH-C, and 39 (30%), non-A-G hepatitis. Follow-up of the 90 TAH-C cases revealed viremia with chronic hepatitis in 38%, viremia without chronic hepatitis in 39%, anti-HCV without viremia in 17%, and no residual HCV markers in 7%. Thirty-five percent of 20 TAH-C patients biopsied for biochemically defined chronic hepatitis displayed cirrhosis, representing 17% of all those originally HCV-infected. Clinically evident liver disease was observed in 86% with cirrhosis but in only 23% with chronic hepatitis alone. Thirty percent of non-A, non-B hepatitis cases were unrelated to hepatitis viruses A,B,C, and G, suggesting another unidentified agent. In conclusion, all-cause mortality approximately 25 years after acute TAH-C is high but is no different between cases and controls. Liver-related mortality attributable to chronic hepatitis C, though low (<3%), is significantly higher among the cases. Among living patients originally HCV-infected, 23% have spontaneously lost HCV RNA.


Assuntos
Hepatite C/etiologia , Hepatite C/mortalidade , Hepatite Viral Humana/etiologia , Hepatite Viral Humana/mortalidade , Reação Transfusional , Idoso , Estudos de Coortes , Feminino , Seguimentos , Hepatite C/complicações , Hepatite C/epidemiologia , Hepatite C/imunologia , Anticorpos Anti-Hepatite C/análise , Hepatite Viral Humana/epidemiologia , Hepatite Viral Humana/imunologia , Humanos , Incidência , Cirrose Hepática/virologia , Masculino , Pessoa de Meia-Idade , Análise de Sobrevida , Viremia/epidemiologia
2.
Proc Natl Acad Sci U S A ; 97(22): 12176-81, 2000 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-11016950

RESUMO

We report the complete sequence of an extreme halophile, Halobacterium sp. NRC-1, harboring a dynamic 2,571,010-bp genome containing 91 insertion sequences representing 12 families and organized into a large chromosome and 2 related minichromosomes. The Halobacterium NRC-1 genome codes for 2,630 predicted proteins, 36% of which are unrelated to any previously reported. Analysis of the genome sequence shows the presence of pathways for uptake and utilization of amino acids, active sodium-proton antiporter and potassium uptake systems, sophisticated photosensory and signal transduction pathways, and DNA replication, transcription, and translation systems resembling more complex eukaryotic organisms. Whole proteome comparisons show the definite archaeal nature of this halophile with additional similarities to the Gram-positive Bacillus subtilis and other bacteria. The ease of culturing Halobacterium and the availability of methods for its genetic manipulation in the laboratory, including construction of gene knockouts and replacements, indicate this halophile can serve as an excellent model system among the archaea.


Assuntos
Genoma Bacteriano , Halobacterium/genética , Evolução Biológica , Membrana Celular/metabolismo , Reparo do DNA , Replicação do DNA , Metabolismo Energético , Halobacterium/metabolismo , Bicamadas Lipídicas , Dados de Sequência Molecular , Biossíntese de Proteínas , Recombinação Genética , Transdução de Sinais , Transcrição Gênica
3.
Immunogenetics ; 49(10): 851-9, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10436178

RESUMO

Animal models of autoimmune diseases have been instrumental in advancing our understanding of autoimmunity in humans. Collagen-induced arthritis (CIA) in mice is an autoimmune disease model of rheumatoid arthritis. Susceptibility to CIA in mice is linked to genes of the major histocompatibility complex (MHC). CD4(+) T cells that express the T-cell receptor (TCR) Tcra-V11.1 and/or Tcrb-V8.2 play a key role in the pathogenesis of arthritis in the DBA/1 mouse (H2(q)). We identified an inbred mouse strain, FVB/NJ (H2(q)), that is resistant to arthritis induction and exhibits a genomic deletion of certain Tcrb-V gene segments. We report a novel polymerase chain reaction-based method for the rapid identification of new mouse strains that exhibit germline Tcrb-V gene deletions. We mapped for the first time both the 5' and 3' breakpoints of the Tcrb-V deletion in the FVB/NJ, SWR, SJL, C57L, and C57BR strains to within 1.1 kilobases. Since there is an association between a particular Tcra-V allele (Tcra-V11.1(d)) and arthritis susceptibility in H2(q) mouse strains, we examined the allelic polymorphisms of the Tcra-V11 gene subfamily members between the arthritis-susceptible DBA/1 mouse and the arthritis-resistant FVB/NJ mouse strain. The amino acid sequences of the Tcra-V11.1 alleles differ at two positions (codons 18 and 68). Therefore, the resistance of FVB/NJ mouse to arthritis induction may be due in part to Tcra-V11.1 coding sequence polymorphism and Tcrb-V8.2 gene segment deletion, as we have recently demonstrated in the case of SWR mouse strain.


Assuntos
Artrite/genética , Artrite/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Deleção de Sequência , Sequência de Aminoácidos , Animais , Artrite/etiologia , Sequência de Bases , Colágeno/imunologia , Primers do DNA/genética , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Endogâmicos , Dados de Sequência Molecular , Polimorfismo Genético , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico , Especificidade da Espécie , Linfócitos T/imunologia
4.
Immunogenetics ; 49(9): 764-72, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10398803

RESUMO

Collagen type II-induced arthritis (CIA) develops in susceptible mouse strains after intradermal injections of type II collagen (CII) in complete Freund's adjuvant (CFA). Susceptibility to CIA in mice is linked to genes of the major histocompatibility complex (MHC). Although the SWR mouse has a susceptible MHC haplotype (H2q), it is resistant to CIA. SWR exhibits at least two known immunological defects: (1) it contains a germline deletion of about 50% of T-cell receptor (TCR) Vbeta-chain gene segments, and (2) SWR is deficient in complement component C5. It has been shown that T cells that express TCRValpha11.1 and TCRVbeta8.2 play a substantial role in the pathogenesis of arthritis in the DBA/1 mouse (H2q). We generated SWR transgenic (tg) mice to determine whether the expression of pathogenic Valpha11.1 and/or Vbeta8.2 transgenes would confer arthritis susceptibility. Arthritis was induced in the SWR TCRalphabeta tg mice, but not in SWR TCRbeta tg mice. To address the role of Valpha11.1 in arthritis susceptibility, we examined the allelic polymorphisms of the Tcra-V11-gene subfamily members between the arthritis susceptible DBA/1 mouse and the arthritis-resistant SWR mouse strain. The amino acid sequences of the Valpha11.1 alleles differ at two positions (codons 18 and 68). Accordingly, these two amino acid changes are sufficient to allow the production of pathogenic T cells in SWR mice. This is the first demonstration of the association of a particular Tcra-V allele and arthritis susceptibility in mice.


Assuntos
Artrite/genética , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Animais , Artrite/patologia , Linfócitos B/imunologia , Colágeno/imunologia , Epitopos , Deleção de Genes , Predisposição Genética para Doença , Região Variável de Imunoglobulina/metabolismo , Articulações/patologia , Camundongos , Camundongos Endogâmicos DBA , Camundongos Endogâmicos , Camundongos Transgênicos , Dados de Sequência Molecular , Polimorfismo Genético
5.
J Immunol ; 157(7): 2900-8, 1996 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-8816395

RESUMO

Mature human lymphocytes are unique targets of 1 alpha,25-dihydroxyvitamin D3 (1 alpha,25(OH)2D3) in that vitamin D receptors (VDR) are not constitutively expressed, and specific cellular activation signals are required for both the up-regulation of VDR and establishment of reactivity to the lipophilic ligand. Treatment of B lymphocytes with the cytokine IL-4 (IL-4), in the absence of prior activation, induces a weak up-regulation of VDR expression but fails to generate vitamin D-responsive element (VDRE)-reactive nuclear protein complexes or to initiate the genomic transcription of 25-hydroxyvitamin D3 24-hydroxylase. Stimulation of B lymphocytes by either ligation of CD40 Ag or cross-linking the Ig receptor is also insufficient to render B lymphocytes responsive to 1 alpha,25(OH)2D3. However, this apparent lack of response to the secosterol can be overcome by stimulation of B lymphocytes with a combination of these cellular activation signals, which are sufficient to lead to G1 cell cycle progression. In the presence of 1 alpha,25(OH)2D3, cellular activation associated with stimulation of such a progression appears to be sufficient for the up-regulation of VDR message and protein and necessary for the establishment of VDRE binding complexes and the induction of 24-hydroxylase message. Furthermore, biologic functions are modulated, in that the hormone inhibits proliferation in a subset of the activated B cells. These observations suggest that reactivity to 1 alpha,25(OH)2D3 is tightly regulated in B lymphocytes, requiring specific signals for its initiation.


Assuntos
Linfócitos B/efeitos dos fármacos , Calcitriol/farmacologia , Sistema Enzimático do Citocromo P-450 , Regulação da Expressão Gênica/efeitos dos fármacos , Interleucina-4/farmacologia , Receptores de Calcitriol/biossíntese , Esteroide Hidroxilases/biossíntese , Linfócitos B/imunologia , Sequência de Bases , Antígenos CD40/imunologia , Ciclo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Indução Enzimática/efeitos dos fármacos , Humanos , Interleucina-2/farmacologia , Ativação Linfocitária , Dados de Sequência Molecular , Monócitos , Proteínas Nucleares/metabolismo , Tonsila Palatina/imunologia , Receptores de Calcitriol/genética , Proteínas Recombinantes/farmacologia , Sequências Reguladoras de Ácido Nucleico , Esteroide Hidroxilases/genética , Linfócitos T/imunologia , Células Tumorais Cultivadas , Regulação para Cima/efeitos dos fármacos , Vitamina D3 24-Hidroxilase
6.
Exp Cell Res ; 225(1): 143-50, 1996 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-8635507

RESUMO

RWLeu4 is a chronic myelogenous leukemia cell line that is sensitive to the antiproliferative and differentiation-inducing actions of 1alpha,25(OH)2-vitamin D3 (VD3). The JMRD3 cell line is a VD3-resistant variant of RWLeu4 that was selected by continuous passage of RWLeu4 in the presence of VD3. The isolation of a spontaneous VD3-resistant variant suggests that phenotypically different cells exist within the RWLeu4 cell population. Therefore, single-cell clones of RWLeu4 cells were isolated and characterized. Four clonal cell populations that fall into three groups differing in response to the antiproliferative and differentiation-inducing actions of VD3 were examined. Surprisingly, the extent of response of the clones to VD3 does not show a correlation with the basal level of the vitamin D receptor (VDR). RWLeu4-3 and RWLeu4-4 are the clones most sensitive to the antiproliferative actions of VD3 (ED50 approximately equal to 1 nM); however, RWLeu4-3 expresses basal levels of VDRs similar to those found in the parental cells and the RWLeu4-2 clone, while in RWLeu4-4, VD3 binding and VDR protein are below the limits of detection. Furthermore, RWLeu4-10 expresses the highest basal level of VDR protein but is relatively resistant to the antiproliferative actions of VD3 (ED50 > or = 30 nM). Like JMRD3, RWLeu4-10 is still capable of differentiating in response to VD3, as judged by the induction of biochemical processes and cell-surface antigen expression. Although VD3 treatment increases VDR protein levels and DNA-binding activity in all clones, altered DNA-protein complexes are detected in RWLeu4-4. Our results suggest that sensitivity to the antiproliferative and differentiation-inducing actions of VD3 is not dependent solely upon the level of VDR expressed, but may also require posttranslational modification of the VDR or complex interactions with other nuclear transcription factors.


Assuntos
Colecalciferol/farmacologia , Receptores de Calcitriol/metabolismo , Sequência de Bases , Carboxilesterase , Hidrolases de Éster Carboxílico/metabolismo , Diferenciação Celular , Células Clonais , DNA/metabolismo , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva , Receptores de Lipopolissacarídeos/metabolismo , Antígeno de Macrófago 1/metabolismo , Dados de Sequência Molecular , Nitroazul de Tetrazólio/metabolismo , Oligodesoxirribonucleotídeos , Células Tumorais Cultivadas
7.
J Biol Chem ; 270(34): 19676-9, 1995 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-7649976

RESUMO

1,25-Dihydroxyvitamin D3 inhibits the proliferation of the chronic myelogenous leukemia cell line RWLeu-4 but not the resistant variant, JMRD3. Although these cells exhibit no detectable differences in the vitamin D receptor, alterations in the interaction of nuclear extracts with the osteocalcin-1,25-dihydroxyvitamin D3-response element are noted. It is shown herein that the 1,25-dihydroxyvitamin D3 receptor binds to the osteocalcin-1,25-dihydroxyvitamin D3-response element along with activator protein-1 (AP-1) complexes and that the DNA binding activities of members of the Jun and Fos proto-oncogene families, which make up the AP-1 transcription factor, are differentially regulated by 1,25-dihydroxyvitamin D3. It is shown that JunD DNA binding activity is enhanced by 1,25-dihydroxyvitamin D3 during cell cycle arrest in the sensitive cells but is decreased in the resistant cells. These results suggest that the level of JunD DNA binding activity may be a critical factor in the regulation of proliferation.


Assuntos
Calcitriol/farmacologia , Proteínas Proto-Oncogênicas c-jun/metabolismo , Sequência de Bases , Divisão Celular/efeitos dos fármacos , DNA de Neoplasias/genética , DNA de Neoplasias/metabolismo , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Dados de Sequência Molecular , Ligação Proteica , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas c-fos/metabolismo , Receptores de Calcitriol/efeitos dos fármacos , Receptores de Calcitriol/metabolismo , Fator de Transcrição AP-1/metabolismo , Células Tumorais Cultivadas
8.
Gastroenterology ; 108(2): 360-6, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7835577

RESUMO

BACKGROUND/AIMS: The inability to precisely measure the area of Barrett's metaplasia has impaired the study of its natural history and response to therapy. This study used a novel computer program that creates two-dimensional maps of the esophagus allowing for calculation of the area of Barrett's metaplasia. METHODS: Endoscopic photographs of Barrett's models and patients were obtained by independent endoscopists. The program transformed the photographs into maps, and the area of Barrett's metaplasia was calculated. RESULTS: Using models, calculated areas correlated with actual areas (r = 0.96) with an overall error of 5.2%. Color, size, shape, diameter of the model, or endoscopist's experience did not affect the accuracy. Accuracy did improve by decreasing the interval between photographs from 4 cm (10.0% error) to 2 cm (4.8% error). In patients, area calculations from maps created by independent technicians correlated precisely (r = 0.99) at 1-cm (n = 22) and 2-cm (n = 40) intervals. Independent endoscopists correlated precisely in producing photographs for map construction (r = 0.99; n = 20). CONCLUSIONS: This novel computer technology produces two-dimensional maps of Barrett's metaplasia that can be used to accurately calculate area. Minimal interobserver variability in obtaining photographs is found.


Assuntos
Esôfago de Barrett/patologia , Esôfago/patologia , Processamento de Imagem Assistida por Computador/métodos , Adulto , Esofagoscopia , Humanos , Metaplasia/patologia , Variações Dependentes do Observador , Reprodutibilidade dos Testes
9.
Blood ; 84(12): 4283-94, 1994 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-7994044

RESUMO

A variant of the chronic myelogenous leukemia cell line, RWLeu-4, that is resistant to the antiproliferative effects of vitamin D3 was established. Although RWLeu-4 proliferation is inhibited by 1 nmol/L vitamin D3, the resistant cells (JMRD3) continue to proliferate in the presence of 100 nmol/L vitamin D3. Both cells express similar patterns of differentiation-specific antigens after treatment with vitamin D3, and both express the retinoblastoma gene product (p110Rb). Vitamin D3 treatment of the sensitive RWLeu-4 cells decreased the level of the p110Rb protein, as well as its phosphorylation. In contrast, vitamin D3 treatment of JMRD3 had no effect on p110Rb expression or phosphorylation. Both RWLeu-4 and JMRD3 express similar vitamin D3 receptors and vitamin D3-inducible enzyme activities. Differences were detected in the DNA binding characteristics of the vitamin D3 receptors as determined by electrophoretic mobility shift studies. However, sequence analysis of the DNA-binding domain and immunoblot analysis showed no differences in the receptors. We conclude that some process subsequent to vitamin D3 receptor activation is altered in JMRD3 that partially separates vitamin D3-induced inhibition of proliferation from the induction of differentiation.


Assuntos
Calcitriol/farmacologia , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Proteínas de Neoplasias/biossíntese , Receptores de Calcitriol/metabolismo , Proteína do Retinoblastoma/biossíntese , Células Tumorais Cultivadas/efeitos dos fármacos , Sequência de Bases , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , DNA de Neoplasias/metabolismo , Resistência a Medicamentos , Humanos , Dados de Sequência Molecular , Proteínas de Neoplasias/genética , Fosforilação/efeitos dos fármacos , Ligação Proteica , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Receptores de Calcitriol/genética , Proteína do Retinoblastoma/genética , Acetato de Tetradecanoilforbol/farmacologia
10.
J Cancer Res Clin Oncol ; 118(3): 190-4, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1372318

RESUMO

We evaluated the proliferative and differentiative effects of analogs of 1,25(OH)2 vitamin D3 [1,25(OH)2D3] on a chronic myelogenous leukemia cell line, RWLeu-4, which is growth-inhibited and differentiates in response to 1,25(OH)2D3 (ED50 = 3-10 nM). Side-chain-fluorinated analogs were more potent (ED50 = 0.7-2 nM) while most of those with altered saturation of the D ring or side-chain carbon-carbon bonds were equally or less effective than 1,25(OH)2D3. However, the two analogs with either two additional double bonds or an extra double and triple bond in the D ring had greater antiproliferative activity [1,25(OH)2-16,23-diene D3 (ED50 = 2.7 nM) and 1,25(OH)2-16-ene-23-yne D3 (ED50 = 0.7 nM)]. Since the latter of these has been reported to be less potent at mobilizing calcium than 1,25(OH)2D3, it (or a similar compound) may be a candidate for clinical use as an antineoplastic agent.


Assuntos
Calcitriol/farmacologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Antígenos CD/análise , Antígenos de Diferenciação Mielomonocítica/análise , Calcitriol/análogos & derivados , Diferenciação Celular/efeitos dos fármacos , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/imunologia , Receptores de Lipopolissacarídeos , Antígeno de Macrófago 1/análise , Relação Estrutura-Atividade , Células Tumorais Cultivadas/efeitos dos fármacos
11.
Dig Dis Sci ; 35(6): 673-80, 1990 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2188819

RESUMO

The Veterans Administration entered the clinical liver transplant field in 1983 and continued its program through July 1988. During this time interval, from the 172 Veterans Administration Medical Centers in the United States, 146 contact calls were initiated to the single center authorized to do liver transplants for the Veterans Administration. One hundred one (69%) of these contact calls resulted in a patient evaluation. Of the 101 patients evaluated, 77 (76%) were accepted for liver transplantation (OLTx). Of these 77, 67 (87%) were transplanted. The reasons for denial of transplant evaluation were numerous and included metastatic cancer, active alcoholism, homosexuality, and a variety of concurrent medical problems. The reasons for denying liver transplantation after evaluation were similar and included concurrent medical problems that contraindicated transplantation (N = 14), metastatic cancer (N = 6), and liver disease of insufficient severity to justify transplantation (N = 3). The number of transplants performed annually by the Veterans Administration increased from one in 1983 to 21 in 1988. Seventeen second grafts and two third grafts were transplanted in 17 cases, resulting in a retransplant rate of 22%; 46% of the patients receiving a second graft survived. None of those receiving three grafts survived. The reasons for retransplantation included acute and/or chronic rejection (N = 6), hepatic artery thrombosis (N = 5), primary graft failure (N = 4), recurrent cancer (N = 2), fulminant hepatitis and portal venous emboli (one each). A total of 45 transplanted patients are still alive (67% of those transplanted).(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Hepatopatias/terapia , Transplante de Fígado , United States Department of Veterans Affairs , Humanos , Hepatopatias/mortalidade , Transplante de Fígado/mortalidade , Estudos Prospectivos , Reoperação , Sobrevida , Análise de Sobrevida , Estados Unidos
12.
Cancer Res ; 50(10): 3087-94, 1990 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-2159372

RESUMO

The effects of 1 alpha, 25-dihydroxyvitamin D3 (VD3) on proliferation, differentiation, and macromolecular synthesis in the new Philadelphia chromosome-positive chronic myelogenous leukemia cell line, RWLeu-4, were investigated. Binding of [3H]VD3 was saturable, with approximately 2000-3000 sites/cell, and half-maximal binding occurring at 0.21-0.33 nM. Treatment of RWLeu-4 cells with VD3 induced 24R-hydroxylase activity, a marker of vitamin D3 responsiveness in many tissues. Exposure of RWLeu-4 cells to VD3 also inhibited proliferation and DNA synthesis with a 50% effective dose of 3.5-10 nM within 72 h; in addition, protein and RNA synthesis were inhibited by VD3 treatment. Exposure of RWLeu-4 cells to 5 nM VD3 for 72 h caused 50% of the cells to differentiate into macrophage/monocyte type cells as judged by nitroblue tetrazolium staining and adherence to plastic. Progressive expression of cell surface maturation-specific antigens of the monocyte/macrophage lineage was induced by treatment of RWLeu-4 cells with VD3 for 24 to 72 h at doses that inhibited cellular proliferation. c-myc RNA, which is constitutively expressed in RWLeu-4 cells, increased after 0.5 h of treatment with 50 nM VD3 and then rapidly decreased to barely detectable levels after 4 h of treatment. Finally, the in vitro tyrosine kinase activity associated with the p210bcr-abl oncogene product was decreased approximately 50% by VD3 treatment. Because of the presence of a functional receptor-effector system for VD3 and multiple biological responses to the hormone, these cells provide a unique model system with which to probe the specific effects of VD3 on cell growth and differentiation in chronic myelogenous leukemia.


Assuntos
Calcitriol/farmacologia , Sistema Enzimático do Citocromo P-450 , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Macrófagos/citologia , Monócitos/citologia , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , DNA de Neoplasias/biossíntese , Indução Enzimática/efeitos dos fármacos , Proteínas de Fusão bcr-abl/metabolismo , Expressão Gênica , Humanos , Técnicas In Vitro , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-myc , RNA Mensageiro/genética , RNA Neoplásico/genética , Receptores de Calcitriol , Receptores de Esteroides/fisiologia , Esteroide Hidroxilases/biossíntese , Células Tumorais Cultivadas , Vitamina D3 24-Hidroxilase
14.
Am J Gastroenterol ; 84(7): 794-7, 1989 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2545094

RESUMO

We report a case of toxic megacolon manifesting in cytomegalovirus (CMV) colitis in a 55-yr-old man with steroid-dependent chronic obstructive pulmonary disease. He presented to the hospital with increasing dyspnea and low-grade fever. His hospital course was characterized by the poor response of his symptoms to treatment, and by the subsequent development of intermittent hematochezia and, eventually, acute abdomen. The surgical specimen showed dilatation of the cecum and ascending colon with a solitary mucosal ulcer in the latter. The major histologic changes were limited to the area of ulceration. In addition to classical CMV inclusions. vasculitis manifested in two forms, namely, leukocytoclastic type and fibrinoid necrosis. The patient died shortly thereafter, due to multi-organ system failure. To our knowledge, this represents the first reported case of toxic megacolon due to CMV infection without underlying inflammatory bowel disease. The pathogenesis of toxic colonic dilatation remains unknown.


Assuntos
Colite Ulcerativa/etiologia , Colite/complicações , Infecções por Citomegalovirus/complicações , Megacolo Tóxico/etiologia , Colite/patologia , Citomegalovirus/ultraestrutura , Infecções por Citomegalovirus/patologia , Humanos , Corpos de Inclusão Viral/ultraestrutura , Masculino , Megacolo Tóxico/patologia , Pessoa de Meia-Idade
15.
Mol Endocrinol ; 2(6): 528-35, 1988 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-3419435

RESUMO

Alternative splicing of insulin-like growth factor I (IGF-I)/somatomedin C mRNAs generates two IGF-I mRNAs coding for IGF-I peptides with different sequences in the E domain of the IGF-I prohormone. These two mRNAs encode alternative E peptides due to the presence (IGF-Ib) or absence (IGF-Ia) of a 52-base insert in the region coding for the E domain. We have used a solution hybridization/RNase protection assay to determine the tissue distribution and regulation by GH of the expression of these alternative IGF-I mRNAs. IGF-Ib mRNAs are present in low abundance (representing approximately 2.5% of the total IGF-I mRNA) in heart, lung, muscle, testes, stomach, kidney, and brain, but represent approximately 13% of the IGF-I mRNA in liver. GH treatment of hypophysectomized rats increased steady-state IGF-I mRNA levels in liver, kidney, lung, and heart. In kidney, lung, and heart, IGF-Ia and IGF-Ib mRNA levels were coordinately regulated by GH, but, in liver, the fold increase in IGF-Ib mRNA levels was approximately three times greater than the fold increase in IGF-Ia mRNA levels. These data suggest that the processing of IGF-I mRNA in liver is different than in nonhepatic tissues. These results also further elucidate the organization of the rat IGF-I gene as well as the generation of multiple IGF-I mRNAs by alternative splicing.


Assuntos
Regulação da Expressão Gênica , Fator de Crescimento Insulin-Like I/genética , Fígado/metabolismo , Fragmentos de Peptídeos/genética , RNA Mensageiro/metabolismo , Somatomedinas/genética , Animais , Hormônio do Crescimento/farmacologia , Hipofisectomia , Masculino , Hibridização de Ácido Nucleico , Splicing de RNA , Ratos , Ratos Endogâmicos , Ribonucleases , Soluções , Distribuição Tecidual
17.
Proc Natl Acad Sci U S A ; 84(24): 8946-50, 1987 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3480521

RESUMO

Rat insulin-like growth factor I (IGF-I) cDNAs contain three alternative 5' untranslated sequences (termed class A, B, and C), which are associated with an identical coding region for the mature IGF-I peptide. A solution hybridization/RNase protection assay was used to simultaneously quantitate the relative abundance of IGF-I transcripts with the different 5' untranslated regions. In all the tissues studied, transcripts with the class C 5' untranslated region were most abundant. In contrast, both class A and B transcripts were tissue specific. Class A transcripts were present in moderate abundance in liver; in low abundance in kidney, lung, testes, and stomach; and were undetectable in muscle, heart, and brain; whereas class B transcripts were detected only in liver. These three classes of 5' untranslated region were also regulated independently by growth hormone. In liver, heart, kidney, and lung, growth hormone increased the abundance of class C transcripts 2- to 3-fold. In liver, growth hormone increased the abundance of the class A and B transcripts 6- to 7-fold. In lung and kidney, on the other hand, the abundance of class A transcripts was not affected by growth hormone. Thus, rat IGF-I gene transcripts contain one of three alternative 5' untranslated regions, which are expressed in a tissue-specific manner and are differentially regulated by growth hormone. Finally, cDNA probes unique to two of the three 5' untranslated regions hybridized to all three major species of IGF-I mRNA typically seen on RNA blots with a coding region probe.


Assuntos
Fator de Crescimento Insulin-Like I/genética , RNA Mensageiro/genética , Somatomedinas/genética , Animais , Regulação da Expressão Gênica/efeitos dos fármacos , Hormônio do Crescimento/farmacologia , Biossíntese de Proteínas , Processamento Pós-Transcricional do RNA , Ratos , Distribuição Tecidual
18.
Biochem Biophys Res Commun ; 146(3): 1154-9, 1987 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-3619921

RESUMO

DNA sequencing of several independent rat IGF-I cDNA clones has revealed three different 5'-untranslated region sequences which contain multiple, upstream, in-frame initiation codons. Use of these codons could generate N-terminal heterogeneity in IGF-I precursor proteins. One of these 5'-untranslated region sequences contains a 40-bp segment which is an inverted repeat of a region in the common 3'-untranslated region. The ends of the IGF-I mRNA corresponding to this cDNA could form a stable duplex structure. Such a complex could prevent ribosomal access to the AUG codons preceding the coding region for the pre-pro-IGF-I peptide, suggesting the possibility of translational regulation of this form of IGF-I mRNA. The 3'-untranslated region inverted repeat sequence also is present in human and mouse IGF-I cDNA's, and, intriguingly, is more highly conserved than the rest of the 3'-untranslated region.


Assuntos
DNA/metabolismo , Fator de Crescimento Insulin-Like I/genética , Somatomedinas/genética , Animais , Sequência de Bases , Clonagem Molecular , Fígado/metabolismo , Biossíntese de Proteínas , RNA Mensageiro/genética , Ratos
19.
Mol Endocrinol ; 1(3): 243-8, 1987 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3453891

RESUMO

Two classes of insulin-like growth factor I (IGF-I) cDNAs were isolated from an adult rat liver library using a human IGF-I cDNA probe. The two types of rat IGF-I cDNA differed by the presence or absence of a 52-base pair insert which altered the derived C-terminal amino acid sequence of the E peptide, but not the 3'-untranslated region or the sequence coding for the mature IGF-I protein. When probes derived from these cDNA clones were hybridized to Northern blots of rat mRNA, specific bands of 8.6, 2.1, and 1.0-1.4 kilobases were seen. Hybridization to poly(A)+ RNA from various tissues from GH-treated and control rats demonstrated an increase in IGF-I mRNA due to GH treatment in all tissues examined.


Assuntos
DNA/genética , Hormônio do Crescimento/farmacologia , Fator de Crescimento Insulin-Like I/genética , Fígado/metabolismo , RNA Mensageiro/efeitos dos fármacos , Somatomedinas/genética , Animais , Sequência de Bases , Clonagem Molecular/métodos , DNA/isolamento & purificação , Fator de Crescimento Insulin-Like I/isolamento & purificação , Fígado/análise , Masculino , Dados de Sequência Molecular , RNA Mensageiro/genética , Ratos , Ratos Endogâmicos , Transcrição Gênica
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