Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 246
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Exp Med ; 192(11): 1601-10, 2000 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-11104802

RESUMO

Helicobacter pylori infection induces various gastroduodenal diseases. We examined the role of two genes, vacA and cagE, in the gastric pathogenesis induced by H. pylori using a long-term (62 wk) animal model. Reportedly, both genes are associated with the virulence of H. pylori: vacA encodes vacuolating cytotoxin, and cagE, with other genes in the cag pathogenicity islands, encodes a type IV secretion system. Mongolian gerbils were challenged in this study by a wild-type TN2 strain and its isogenic mutants of cagE or vacA. The wild-type and vacA mutants induced severe gastritis, whereas cagE mutants induced far milder changes. Gastric ulcer was induced at the highest rate (22/23) by the wild-type TN2, followed by the vacA mutant (19/28). No ulcer was found in the gerbils infected with the cagE mutant (0/27) or in controls (0/27). Intestinal metaplasia was also found in the gerbils infected with the wild-type (14/23) or vacA mutant (15/28). Gastric cancer developed in one gerbil with wild-type infection and in one with vacA mutant infection. In conclusion, the knocking out of the cagE gene deprived wild-type H. pylori of the pathogenicity for gastritis and gastric ulcer, suggesting that the secretion system encoded by cag pathogenicity island genes plays an essential role.


Assuntos
Antígenos de Bactérias , Proteínas de Bactérias/fisiologia , Toxinas Bacterianas , Citotoxinas/fisiologia , Helicobacter pylori/patogenicidade , Gastropatias/microbiologia , Adenocarcinoma/microbiologia , Adenocarcinoma/patologia , Animais , Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , Citotoxinas/genética , Modelos Animais de Doenças , Mucosa Gástrica/microbiologia , Mucosa Gástrica/patologia , Gastrite/microbiologia , Gastrite/patologia , Genoma Bacteriano , Gerbillinae , Helicobacter pylori/genética , Helicobacter pylori/crescimento & desenvolvimento , Masculino , Mutagênese , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Gastropatias/patologia , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/patologia , Úlcera Gástrica/microbiologia , Úlcera Gástrica/patologia , Fatores de Tempo , Virulência
2.
J Clin Invest ; 103(12): 1635-40, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10377169

RESUMO

The emergence of resistant hepatitis B virus (HBV), with mutations in the YMDD motif of the polymerase gene after treatment with lamivudine, is becoming an important clinical problem. In this study, susceptibility of wild-type and lamivudine-resistant HBV M552I, M552V, and L528M/M552V mutants to other reverse transcriptase inhibitors was investigated by transient transfection of full-length HBV DNA into human hepatoma cells. HBV DNA replication was monitored by Southern blot hybridization, which showed the presence of a single-stranded band (representative of the HBV replicative intermediates) in the drug-free, wild-type HBV-transfected cells. This band was diminished in the samples of wild-type HBV DNA treated with either lamivudine, adefovir, or lobucavir. The band intensities from the lamivudine-resistant mutants were not decreased by treatment with lamivudine, but were decreased by the treatments with adefovir or lobucavir. In contrast, penciclovir and nevirapine did not diminish the intensity of the single-stranded band of wild-type HBV or the lamivudine-resistant mutants. These results demonstrate that lamivudine-resistant HBV is susceptible to adefovir and lobucavir. Lamivudine-resistant HBV should be treated with adefovir or lobucavir, and combination therapy with lamivudine and adefovir/lobucavir may prevent the emergence of lamivudine-resistant HBV.


Assuntos
Vírus da Hepatite B/efeitos dos fármacos , Lamivudina/farmacologia , Organofosfonatos , Inibidores da Transcriptase Reversa/farmacologia , Aciclovir/análogos & derivados , Aciclovir/farmacologia , Adenina/análogos & derivados , Adenina/farmacologia , Carcinoma Hepatocelular , Resistência Microbiana a Medicamentos/genética , Guanina/análogos & derivados , Guanina/farmacologia , Vírus da Hepatite B/enzimologia , Vírus da Hepatite B/genética , Humanos , Mutagênese Sítio-Dirigida , Nevirapina/farmacologia , Transfecção , Células Tumorais Cultivadas
3.
J Clin Invest ; 107(4): 449-55, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11181644

RESUMO

After receiving lamivudine for 3 years to treat chronic hepatitis B, 67-75% of patients develop B-domain L528M, C-domain M552I, or M552V mutations in the HBV polymerase that render hepatitis B virus (HBV) drug-resistant. The aim of this study was to evaluate the influence of these mutations on viral replication and resistance to antiviral agents. We investigated the replication fitness and susceptibility of the wild-type and five mutant HBVs (L528M, M552I, M552V, L528M/M552I, and L528M/M552V) to 11 compounds [lamivudine, adefovir, entecavir (BMS-200475) (+)-BCH-189 (+/-)-FTC (racivir) (-)-FTC (emtricitabine) (+)-FTC, L-D4FC, L-FMAU (clevudine), D-DAPD, and (-)-carbovir] by transfecting HBV DNA into hepatoma cells and monitoring viral products by Southern blotting. The replication competency of the single C-domain mutants M552I and M552V was markedly decreased compared with that of wild-type HBV. However, addition of the B-domain mutation L528M restored replication competence. Only adefovir and entecavir were effective against all five HBV mutants, and higher doses of these compounds were necessary to inhibit the double mutants compared with the single mutants. The B-domain mutation (L528M) of HBV polymerase not only restores the replication competence of C-domain mutants, but also increases resistance to nucleoside analogues.


Assuntos
Antivirais/farmacologia , Vírus da Hepatite B/efeitos dos fármacos , Mutação , DNA Polimerase Dirigida por RNA/genética , Replicação Viral , Sítios de Ligação , Células Cultivadas , Resistência a Medicamentos , Vírus da Hepatite B/enzimologia , Vírus da Hepatite B/genética , Humanos , Nucleotídeos/metabolismo
4.
Aliment Pharmacol Ther ; 25(7): 805-12, 2007 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-17373919

RESUMO

BACKGROUND: Although Helicobacter pylori infection is closely associated with gastric cancer development, follow-up studies after H. pylori eradication are still scarce. AIM: To clarify the cancer preventive effect of H. pylori eradication, with special attention to differences in effect according to histology. METHODS: Patients who underwent H. pylori eradication therapy and were followed-up endoscopically for at least 1 year were analysed. The incidence of gastric cancer and factors associated with cancer development were investigated. RESULTS: A total of 1807 patients were enrolled. Six of 1519 H. pylori eradicated and five of 288 persistent subjects developed gastric cancer. Four of the eradicated subjects developed the intestinal type and two the diffuse type, while four of the persistent subjects developed the intestinal type and one the diffuse type. Kaplan-Meier analysis indicated a significantly lower incidence in eradicated patients than in persistent patients. The incidence of intestinal type was significantly lower than in eradicated patients, while the diffuse type could not be evaluated because of the low incidence. CONCLUSIONS: Helicobacter pylori-eradicated patients had a reduced incidence of gastric cancer compared with H. pylori-persistent patients, particularly the intestinal type, suggesting that H. pylori is strongly associated with intestinal-type gastric cancer.


Assuntos
Infecções por Helicobacter/prevenção & controle , Helicobacter pylori , Neoplasias Gástricas/microbiologia , Idoso , Intervalo Livre de Doença , Quimioterapia Combinada , Feminino , Infecções por Helicobacter/mortalidade , Humanos , Incidência , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Neoplasias Gástricas/mortalidade
5.
Dig Liver Dis ; 39(5): 422-9, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17379587

RESUMO

BACKGROUND: The effectiveness of leukocytapheresis against ulcerative colitis has been reported. However, the efficacy of this therapy for steroid-resistant ulcerative colitis patients has hardly been examined. AIMS: The aims of this study are to evaluate the efficacy of leukocytapheresis for steroid-resistant ulcerative colitis patients and to identify clinical factors that predict the efficacy of this therapy for these patients. METHODS: Clinical factors of 71 steroid-resistant ulcerative colitis patients who underwent leukocytapheresis analysed. RESULTS: Of those analysed, 53 (75%) patients showed an initial response to leukocytapheresis. Among cases with initial response, however, only 19 (27%) patients maintained remission for more than 6 months. Steroid-dependent course (Odds ratio =5.53, 95% confidence interval; 1.24-24.73) and a high C-reactive protein degree (Odds ratio=1.6, confidence interval; 1.09-2.35) were predictors of initial response to leukocytapheresis. Rapid response, which means remission induction within three leukocytapheresis sessions, was the only predictor of maintenance of remission for more than 6 months after successful leukocytapheresis therapy (odds ratio=8.01, confidence interval; 1.08-59.37). CONCLUSIONS: Leukocytapheresis was effective for steroid-resistant ulcerative colitis patients. However, relapse was frequently observed within short periods after the initial response to this therapy. Patients without a rapid response should be treated with alternative or additional therapies.


Assuntos
Colite Ulcerativa/terapia , Leucaférese , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Esteroides/uso terapêutico , Resultado do Tratamento
6.
Dig Liver Dis ; 39(1): 40-6, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16996329

RESUMO

AIMS: The purpose of this study was to investigate the clinical characteristics of synchronous cancer patients, with particular attention given to variations in tumour location. METHODS: A retrospective evaluation of 249 synchronous cancer cases out of 3061 consecutive colorectal cancer patients. RESULTS: Multivariate analysis of risk factors for synchronous cancer according to tumour location revealed that male gender was a significant risk for synchronous lesions in the left colon only (odds ratio=2.05, 95% confidence interval 1.34-3.13). Meanwhile, aging was a risk factor for synchronous cancer in the right colon only (odds ratio=1.05, 95% confidence interval 1.02-1.08), and in both sides of the colon (odds ratio=1.03, 95% confidence interval 1.01-1.05), but not in the left colon only (odds ratio=0.98, 95% confidence interval 0.97-1.00). In addition, patients with synchronous lesions in the right colon only tended to have adenomas in the right colon, while those with synchronous lesions in the left colon only tended to have adenomas in the left colon (each P value <0.05). CONCLUSION: The risk factors and status of concurrent adenomas of synchronous cancer cases varied according to tumour location, suggesting that the colonic site susceptible to neoplasia varies according to patient characteristics.


Assuntos
Neoplasias Colorretais/patologia , Segunda Neoplasia Primária/patologia , Adenoma/patologia , Adenoma/cirurgia , Idoso , Ceco/patologia , Colo Ascendente/patologia , Colo Descendente/patologia , Colo Sigmoide/patologia , Colo Transverso/patologia , Colonoscopia , Neoplasias Colorretais/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Segunda Neoplasia Primária/cirurgia , Reto/patologia
7.
Aliment Pharmacol Ther ; 24(3): 519-23, 2006 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-16886918

RESUMO

BACKGROUND: Recently, unusual patients with autoimmune hepatitis, such as male patients, have increased. AIM: To assess clinical feature of Japanese males with type 1 autoimmune hepatitis compared with females. METHODS: We investigated consecutive 160 patients with type 1 autoimmune hepatitis, who consisted of 20 males and 140 females, with a median age of 55 (16-79) years. RESULTS: Compared with females, males had a lower frequency of definite diagnosis according to the revised scoring system proposed by the International Autoimmune Hepatitis Group (40% vs. 85%) and lower serum levels of immunoglobulin G [1932 (1085-3850) mg/dL vs. 2624 (1354-6562) mg/dL]. However, they were similar in age, form of clinical onset, symptomatic concurrent autoimmune disease, human leucocyte antigen DR status and frequency of cirrhosis at the time of diagnosis. The normalization of serum alanine aminotransferase levels within 6 months after the introduction of corticosteroid treatment was lower in males compared with females (73% vs. 93%). CONCLUSIONS: In male patients, a diagnosis of autoimmune hepatitis should be made carefully. In Japanese patients with a dominant frequency of human leucocyte antigen DR4, gender may affect the response to corticosteroid treatment.


Assuntos
Hepatite Autoimune/patologia , Adolescente , Adulto , Idoso , Alanina Transaminase/sangue , Anticorpos/sangue , Anticorpos Antinucleares/sangue , Feminino , Antígenos HLA/sangue , Hepatite Autoimune/etnologia , Humanos , Japão/etnologia , Masculino , Pessoa de Meia-Idade , Músculo Liso/imunologia
8.
Aliment Pharmacol Ther ; 23(9): 1347-53, 2006 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-16629940

RESUMO

BACKGROUND: Although a few adult cases of fulminant-type autoimmune hepatitis have been reported, their clinical features and prognosis have remained uncertain. AIM: To assess the clinical features and prognosis of patients with fulminant-type autoimmune hepatitis. METHODS: Eleven patients (10%) diagnosed with fulminant-type autoimmune hepatitis in accordance with the 1999 criteria of the International Autoimmune Hepatitis Group were analysed. RESULTS: All 11 patients were female, with a median age of 53 years. Five patients survived without liver transplantation, one received a liver transplantation, and five died without liver transplantation. Nine patients (82%) survived for 2 weeks or more following diagnosis, without liver transplantation. Except for the patient receiving a liver transplantation, serum total bilirubin levels measured during the clinical course were significantly higher in non-survivors than in survivors, although the accompanying serum alanine aminotransferase levels measured for the two groups were similar. Most significantly, serum total bilirubin levels in non-survivors worsened during days 8-15, while levels in survivors improved during the same period. CONCLUSIONS: The short-term prognosis for patients with fulminant-type autoimmune hepatitis may be good. However, patients whose serum total bilirubin levels worsen during days 8-15 should be considered for liver transplantation.


Assuntos
Hepatite Autoimune/diagnóstico , Falência Hepática/diagnóstico , Falência Hepática/cirurgia , Transplante de Fígado , Adolescente , Adulto , Idoso , Bilirrubina/sangue , Evolução Fatal , Feminino , Hepatite Autoimune/complicações , Hepatite Autoimune/cirurgia , Humanos , Falência Hepática/complicações , Pessoa de Meia-Idade , Prognóstico
9.
Aliment Pharmacol Ther ; 24(8): 1197-205, 2006 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-17014578

RESUMO

BACKGROUND: Although the prognosis of type 1 autoimmune hepatitis is generally good with immunosuppressive treatment, the disease progresses in some patients despite the treatment. The prognosis may be determined by the clinical course. AIM: To evaluate the long-term prognosis and assess the predictive factors for a serious event, including the development of hepatocellular carcinoma or death. METHODS: Sixty-nine patients with type 1 autoimmune hepatitis were prospectively followed up regularly, with a median follow-up period of 96 months (49-201 months). RESULTS: During the follow-up period, three patients (4%) developed hepatocellular carcinoma, and two of these three patients died. Another patient died of liver failure. The 10-year survival rate was 98%, and the 10-year hepatocellular carcinoma-free rate was 93%. The four patients experiencing a serious event received higher maintenance doses of corticosteroid during their follow-up periods than those did not. However, serum alanine aminotransferase levels during the follow-up period were higher in these four patients than in the others. CONCLUSIONS: Persistent elevation of serum alanine amniotransferase levels during the follow-up period, rather than factors existing prior to medical treatment is considered to be an important prognostic factor, and it is indicated that poor outcomes may result from the resistance to immunosuppressive treatment.


Assuntos
Alanina Transaminase/sangue , Carcinoma Hepatocelular/sangue , Hepatite Autoimune/mortalidade , Neoplasias Hepáticas/sangue , Adolescente , Adulto , Idoso , Anti-Inflamatórios/administração & dosagem , Azatioprina/administração & dosagem , Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/patologia , Colagogos e Coleréticos/administração & dosagem , Esquema de Medicação , Quimioterapia Combinada , Feminino , Hepatite Autoimune/sangue , Hepatite Autoimune/tratamento farmacológico , Humanos , Imunossupressores/administração & dosagem , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prednisolona/administração & dosagem , Estudos Prospectivos , Recidiva , Resultado do Tratamento , Ácido Ursodesoxicólico/administração & dosagem
10.
Cancer Res ; 47(24 Pt 1): 6806-9, 1987 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-3499981

RESUMO

Expression of the human placental form of glutathione S-transferase (GST-pi) in dysplasia (53 cases), carcinoma in situ (10 cases), and invasive carcinoma (46 cases) of human uterine cervix was investigated immunohistochemically with specific anti-GST-pi rabbit antibody. While normal squamous epithelium was largely negative, the binding of antibody was appreciable in mild and moderate dysplasias, especially in the cytoplasm of cells demonstrating koilocytotic atypia. In severe dysplasia, the nuclei as well as the cytoplasm were strongly stained in all cell layers except for the superficial layer, and in carcinoma in situ both of them were also strongly stained in all cell layers. In invasive carcinoma, over 90% of cases exhibited strong cytoplasmic staining and in over 70% the nuclei were positive. GST activity towards 1-chloro-2,4-dinitrobenzene and GST-pi protein content were significantly increased in all of 4 squamous cell carcinomas examined as compared to values for normal cervical epithelia. Two-dimensional gel electrophoresis followed by immunoblotting using the GST-pi antibody demonstrated that, of many cytoplasmic proteins, only the GST-pi subunit was specifically bound. These results indicate that GST-pi is a potentially useful immunohistochemical marker for (pre)neoplasia of human uterine cervix. In addition, it was demonstrated that the cells in severe dysplasia, carcinoma in situ, and invasive carcinoma expressing GST-pi were often characterized by staining with a monoclonal antibody to the v-H-ras gene product.


Assuntos
Glutationa Transferase/análise , Placenta/enzimologia , Displasia do Colo do Útero/enzimologia , Neoplasias do Colo do Útero/enzimologia , Feminino , Humanos , Imuno-Histoquímica , Proteína Oncogênica p21(ras) , Proteínas Oncogênicas Virais/análise , Displasia do Colo do Útero/patologia , Neoplasias do Colo do Útero/patologia
11.
Cancer Res ; 56(24): 5620-3, 1996 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-8971166

RESUMO

Mismatch repair genes are the responsible genes for hereditary non-polyposis colon cancer, and mutation of these genes causes replication error (RER). In several RER-positive colon cancer cell lines, mutations of repetitive sequences of transforming growth factor beta (TGF-beta) type II receptor (RII) gene have been reported. Since TGF-beta inhibits cell proliferation, loss of response to TGF-beta is an important tumor progression step. In this study, the relationship between RER status and mutation of the RII gene was analyzed in 112 cases of various types of sporadic gastrointestinal and hepatobiliary cancer (41 with gastric, 49 with colorectal, 5 with gallbladder, and 17 with hepatic cancers). RER was found in 17 cases (4 with gastric, 12 with colorectal, and 1 with gallbladder cancer), and 10 of those (3 with gastric and 7 with colorectal cancer) showed mutations of the RII gene. Of interest was that in all seven cases with colorectal cancer, tumors were located at the cecum. These data indicate that mutation of the RII gene, presumably caused by abnormality of repair gene, play an important role in carcinogenesis of sporadic gastrointestinal cancer, especially at the cecum.


Assuntos
Neoplasias do Ceco/genética , Neoplasias Colorretais/genética , Replicação do DNA/genética , Mutação/genética , Receptores de Fatores de Crescimento Transformadores beta/genética , Neoplasias Gástricas/genética , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Serina-Treonina Quinases , Receptor do Fator de Crescimento Transformador beta Tipo II
12.
Cancer Res ; 57(3): 461-5, 1997 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-9012474

RESUMO

The alpha-fetoprotein (AFP) gene is normally expressed in fetal liver and is transcriptionally silent in adult liver but overexpressed in human hepatocellular carcinoma (HCC). Here, we demonstrate that replication defective recombinant adenoviral vectors, containing the human AFP promoter/enhancer, can be used to express the Escherichia coli cytosine deaminase (CD) gene (AdAFPCD) and the beta-galactosidase gene (AdAF-PlacZ) in AFP-producing HCC cell lines. Expression of the CD gene by adenovirus from the AFP promoter/enhancer (AdAFPCD) induced cells sensitive to 5-fluorocytosine (5FC) in the AFP-producing cells but not in the AFP-nonproducing cells. Transduction by an adenoviral vector harboring an ubiquitous strong promoter and CD gene showed enzymatic activity and 5FC killing in all cell lines. When AdAFPlacZ was injected into the s.c. established hepatoma in vivo, expression of the beta-galactosidase gene was confined to AFP-producing HCC xenografts. Moreover, HCC xenografts regressed by transduction with AdAFPCD and subsequently with 5FC treatment in vivo. These findings suggest that utilization of the AFP promoter/enhancer in an adenoviral vector can confer selective expression of a heterologous suicide gene in hepatocellular carcinoma cells in vitro and in vivo.


Assuntos
Adenoviridae/genética , Carcinoma Hepatocelular/terapia , Terapia Genética , Neoplasias Hepáticas/terapia , Nucleosídeo Desaminases/genética , alfa-Fetoproteínas/biossíntese , Animais , Carcinoma Hepatocelular/enzimologia , Citosina Desaminase , Humanos , Neoplasias Hepáticas/enzimologia , Camundongos , Camundongos Endogâmicos BALB C , Transplante de Neoplasias , Células Tumorais Cultivadas
13.
Cancer Res ; 57(19): 4279-84, 1997 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-9331089

RESUMO

Previously, we reported that adenoviral vectors carrying the carcinoembryonic antigen (CEA) promoter sequences to direct the Echerichia coli beta-galactosidase gene (AdCEA-lacZ) or cytosine deaminase (CD) gene (AdCEA-CD) confer selective gene expression on a CEA-positive gastric cancer cell line (MKN45) in vitro. Here, adenovirus-mediated tumor-specific gene therapy for CEA-positive gastric carcinoma in vivo was investigated. Using an animal model with i.p. disseminated MKN45 tumors, adenovirus-mediated tumor-specific transgene expression and therapeutic efficacy were analyzed. After an i.p. injection of AdCEA-lacZ, beta-galactosidase activity was confined to tumor xenografts. Moreover, CD mRNA was expressed exclusively in MKN45 tumor xenografts after infection with AdCEA-CD, despite the fact that an adenovirus-mediated transfer of CD DNA was detected in all tissues tested. In contrast, CD mRNA was detected not only in tumor xenografts but also in other organs of mice infected with AdCA-CD, in which CD gene expression is governed by an ubiquitous promoter. Suppression of tumor growth and prolongation of survival were noted in tumor-bearing mice treated with AdCEA-CD and 5-fluorocytosine (5FC) without observable adverse effects. In contrast, significant hepatic toxicity was noted in animals treated with AdCA-CD. These results reveal that the CEA promoter restricts CD gene expression to CEA-positive tumor cells in the adenoviral context in vivo, along with the beneficial therapeutic effects of 5FC treatment, suggesting the i.p. AdCEA-CD/5FC system may provide a novel approach to treatment of i.p. disseminated gastric cancer.


Assuntos
Antígenos de Neoplasias/biossíntese , Antimetabólitos Antineoplásicos/uso terapêutico , Antígeno Carcinoembrionário/biossíntese , Fluoruracila/uso terapêutico , Regulação Viral da Expressão Gênica , Nucleosídeo Desaminases/uso terapêutico , Proteínas Recombinantes de Fusão/uso terapêutico , Neoplasias Gástricas/terapia , Animais , Antígenos de Neoplasias/genética , Antimetabólitos Antineoplásicos/toxicidade , Antígeno Carcinoembrionário/genética , Citosina Desaminase , Escherichia coli/genética , Fluoruracila/toxicidade , Humanos , Camundongos , Camundongos Nus , Nucleosídeo Desaminases/biossíntese , Nucleosídeo Desaminases/genética , Regiões Promotoras Genéticas , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Neoplasias Gástricas/genética , Transplante Heterólogo , beta-Galactosidase/biossíntese , beta-Galactosidase/genética
14.
Cancer Res ; 58(9): 1946-51, 1998 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-9581837

RESUMO

5-fluorouracil (5-FU), although a widely used chemotherapeutic agent, has a limited effect in the treatment of human solid tumors due to their resistance to the cytotoxic effects of 5-FU. Escherichia coli uracil phosphoribosyltransferase (UPRT) is a pyrimidine salvage enzyme that catalyzes the synthesis of UMP from uracil and 5-phosphoribosyl-alpha-1-diphosphate. The present study demonstrates that adenovirus-mediated transduction of E. coli UPRT gene results in marked sensitization of colon, gastric, liver, and pancreas cancer cell lines to low concentration of 5-FU in vitro. The in vitro bystander effect was observed when only 10% of the hepatoma Hep3B cells were infected with UPRT-expressing adenovirus. In addition, 5-FU treatment of human hepatoma or gastric cancer xenografts in nude mice transduced with UPRT was demonstrated to result in significant in vivo antitumor effects. The adenovirus vector transduction of the UPRT gene followed by 5-FU administration is representative of a new chemosensitization strategy for cancer gene therapy.


Assuntos
Adenoviridae/genética , Escherichia coli/enzimologia , Fluoruracila/farmacologia , Genes Bacterianos , Neoplasias Experimentais/enzimologia , Pentosiltransferases/genética , Transfecção , Células Tumorais Cultivadas/enzimologia , Animais , Northern Blotting , Células Cultivadas , Primers do DNA/química , Regulação Enzimológica da Expressão Gênica , Terapia Genética , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Experimentais/tratamento farmacológico , Células Tumorais Cultivadas/efeitos dos fármacos
15.
Cancer Res ; 56(6): 1341-5, 1996 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-8640823

RESUMO

We analyzed the ability of a recombinant replication-defective adenovirus vector with the carcinoembryonic antigen (CEA) promotor to transfer the thymidine kinase gene of herpes simplex virus (HSVtk) into gastric cancer cells to confer sensitivity to ganciclovir (GCV). CEA-producing gastric cancer cell lines (MKN28 and MKN45), a CEA-nonproducing gastric cancer cell line (MKN1), and a human uterine cervical cancer cell line (HeLa) were infected with a recombinant adenovirus carrying lacZ reporter gene coupled to the CEA promoter (AdCEAlacZ). The efficiency of AdCEAlacZ-mediated gene transfer was correlated with the amount of CEA produced by each cell line. Furthermore, the 50% growth inhibitory concentrations (IC50) of GCV were 21 and 5.8 microm for MKN28 and MKN45, respectively, when infected with a recombinant adenovirus carrying the HSVtk gene coupled to the CEA promoter (AdCEAtk). However, MKN1 and HeLa cells infected with AdCEAtk remained resistant to GCV (IC50 > 300 microm of GCV). In addition, a bystander killing effect was demonstrated against MKN45 cells when only 20% of AdCEAtk-infected cells were mixed with uninfected cells. These data indicate the potential for targeted gene therapy using the cell type-specific promotor of the CEA gene against gastric cancers that produce CEA.


Assuntos
Adenoviridae/genética , Antimetabólitos Antineoplásicos/uso terapêutico , Antígeno Carcinoembrionário/biossíntese , Vírus Defeituosos/genética , Ganciclovir/uso terapêutico , Técnicas de Transferência de Genes , Vetores Genéticos/genética , Regiões Promotoras Genéticas/genética , Simplexvirus/enzimologia , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/terapia , Timidina Quinase/genética , Adenoviridae/enzimologia , Adenoviridae/fisiologia , Vírus Defeituosos/enzimologia , Vírus Defeituosos/fisiologia , Feminino , Vetores Genéticos/administração & dosagem , Células HeLa/efeitos dos fármacos , Células HeLa/metabolismo , Humanos , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/genética , Timidina Quinase/fisiologia , Células Tumorais Cultivadas , Neoplasias Uterinas/tratamento farmacológico , Neoplasias Uterinas/metabolismo
16.
Clin Cancer Res ; 3(5): 727-31, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9815742

RESUMO

A goal of cancer chemoprevention is the deletion of latent premalignant or malignant clones before they expand to a clinically detectable tumor. However, such clonal deletion has not been demonstrated in clinical studies. We have evaluated serum levels of lectin-reactive alpha-fetoprotein (AFP-L3), which suggests the presence of latent hepatoma cells, in a randomized controlled trial that used acyclic retinoid to prevent second primary hepatomas in patients who had received treatments that cured initial hepatomas. The trial involved 21 patients in each acyclic retinoid (600 mg daily) and placebo group and consisted of a 12-month period of drug administration and a subsequent follow-up period. Serum AFP-L3 was determined at entry and at the end of the 12-month treatment period using lectin-affinity electrophoresis and antibody-affinity blotting. Although neither treatment affected serum levels of total AFP, acyclic retinoid significantly reduced AFP-L3 levels after a 12-month administration (P < 0.01). Acyclic retinoid not only deleted AFP-L3 from patients who had been positive for AFP-L3 at entry but also prevented the appearance of AFP-L3 in patients who had been negative at entry (P < 0.01). In contrast, placebo significantly raised the incidence of AFP-L3-positive patients after a 12-month administration from that at entry (P < 0.05). Patients positive for AFP-L3 after a 12-month treatment had a significantly higher risk of second primary hepatomas in the subsequent follow-up period (P = 0.03). Acyclic retinoid may have deleted a clone of latent hepatoma cells producing AFP-L3 and thereby inhibited second primary hepatomas. Serum AFP-L3 may be a useful intermediate biomarker in the chemoprevention of second primary hepatomas by acyclic retinoid.


Assuntos
Antineoplásicos/uso terapêutico , Carcinoma Hepatocelular/prevenção & controle , Neoplasias Hepáticas/prevenção & controle , Segunda Neoplasia Primária/prevenção & controle , Tretinoína/análogos & derivados , alfa-Fetoproteínas/análise , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/cirurgia , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Lectinas , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Segunda Neoplasia Primária/sangue , Placebos , Fatores de Tempo , Tretinoína/uso terapêutico
17.
Hepatogastroenterology ; 52(65): 1351-6, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16201072

RESUMO

BACKGROUND/AIMS: The survival time of patients with unresectable malignant biliary stenosis and the patent period of metallic biliary stents are different in each disease. The efficacy of the covered metallic stent was analyzed according to the primary disease. METHODOLOGY: Seventy-three patients with bile duct carcinoma (12 cases), gallbladder carcinoma (22 cases), and pancreas carcinoma (39 cases) were retrospectively enrolled. Covered metallic stents were used in 42 patients and uncovered metallic stents in 31 patients. The patency of covered stents was compared with that of uncovered stents for each disease. RESULTS: The patent rate at 6 months after insertion was 80.6% (95% CI [72.6%, 88.6%]) for the covered stent, and 49.5% (95% CI [37.6%, 61.4%]) for the uncovered stent. The mean patent periods of the covered stent and the uncovered stent were 14.6 and 27.6 months for bile duct carcinoma (p=0.424), 12.7 and 3.0 months for gallbladder carcinoma (p=0.003), and 11.9 and 9.6 months for pancreas carcinoma (p=0.919), respectively. CONCLUSIONS: The covered metallic stent was the most effective in patients with gallbladder carcinoma.


Assuntos
Neoplasias dos Ductos Biliares/complicações , Colestase/terapia , Neoplasias da Vesícula Biliar/complicações , Neoplasias Pancreáticas/complicações , Stents , Adulto , Idoso , Neoplasias dos Ductos Biliares/mortalidade , Colestase/etiologia , Terapia Combinada , Feminino , Neoplasias da Vesícula Biliar/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/mortalidade , Qualidade de Vida , Análise de Sobrevida
18.
Br J Pharmacol ; 86(3): 645-54, 1985 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2866005

RESUMO

The effects of the seven glutamic acid analogues, alpha-kainic acid, alpha-allo-kainic acid, domoic acid, erythro-L-tricholomic acid, DL-ibotenic acid, L-quisqualic acid and allo-gamma-hydroxy-L-glutamic acid were examined on six identifiable giant neurones of an African giant snail (Achatina fulica Férussac). The neurones studied were: PON (periodically oscillating neurone), d-RPLN (dorsal-right parietal large neurone), VIN (visceral intermittently firing neurone), RAPN (right anterior pallial neurone), FAN (frequently autoactive neurone) and v-RCDN (ventral-right cerebral distinct neurone). Of these, d-RPLN and RAPN were excited by the two isomers (erythro- and threo-) of beta-hydroxy-L-glutamic acid (L-BHGA), whereas PON, VIN, FAN and v-RCDN were inhibited. L-Glutamic acid (L-Glu) had virtually no effect on these neurones. alpha-Kainic acid and domoic acid showed marked excitatory effects, similar to those of L-BHGA, on d-RPLN and RAPN. Their effective potency quotients (EPQs), relative to the more effective isomer of L-BHGA were: 0.3 for both substances on d-RPLN, and 1 for alpha-kainic acid and 3-1 for domoic acid on RAPN. alpha-Kainic acid also had excitatory effects on FAN and v-RCDN (EPQ for both: 0.3), which were inhibited by L-BHGA but excited by gamma-aminobutyric acid (GABA). Erythro-L-tricholomic acid showed marked effects, similar to those of L-BHGA, on VIN (EPQ: 0.3) and RAPN (EPQ: 3-1), but produced weaker effects on PON and d-RPLN (EPQ: 0.1). DL-Ibotenic acid produced marked effects, similar to those of L-BHGA, on PON, VIN (EPQ for both: 1) and RAPN (EPQ: 1-0.3), but had weak effects on d-RPLN (EPQ: less than 0.1) and FAN (EPQ: 0.1). It had excitatory effects on v-RCDN (EPQ: 0.1). This neurone was inhibited by L-BHGA but excited by GABA. L-Quisqualic acid showed the same effects as L-BHGA on all of the neurones examined (EPQ range 30-0.1). It was the most potent of the compounds tested on RAPN (EPQ: 30-10), FAN (EPQ: 30) and v-RCDN (EPQ: 3). alpha-Allo-kainic acid and allo-gamma-hydroxy-L-glutamic acid had no obvious effect on any of the neurones examined. As described above, the responses of the neurones examined to these substances varied widely. However, L-quisqualic acid generally had effects on the neurones similar to those of L-BHGA; the L-BHGA-excited neurones were also excited by alpha-kainic acid and domoic acid.


Assuntos
Células Quimiorreceptoras/efeitos dos fármacos , Glutamatos/farmacologia , Neurônios/efeitos dos fármacos , Caramujos/fisiologia , Animais , Ácido Glutâmico , Técnicas In Vitro , Potenciais da Membrana/efeitos dos fármacos , Estereoisomerismo , Relação Estrutura-Atividade
19.
Int J Oncol ; 2(4): 669-75, 1993 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21573610

RESUMO

Recently, ultrasound-guided percutaneous ethanol injection therapy (PEIT) has been widely performed in the treatment of hepatocellular carcinoma. Histopathologic examinations after the therapy have revealed that PEIT can destroy the tumor completely in most cases. Findings in imaging modalities and serum tumor marker levels have also shown a remarkable anticancer effect of this procedure. In addition, PEIT has achieved considerably high long-term survival rates. PEIT is a generally safe procedure and serious complications are rare. PEIT seems to be a valuable therapy and could even be an alternative to surgery in the treatment of hepatocellular carcinoma. This paper reviews the pertinent literature on this new therapy.

20.
Invest Radiol ; 25(6): 651-7, 1990 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2191934

RESUMO

In order to evaluate a possible therapy for hypersplenism, an experiment with animals was done. In nine dogs, 0.6 ml/kg body weight of 5% ethanolamine oleate was injected percutaneously into the spleen under ultrasound guidance. The injection was repeated three times at intervals of 1 week. Three dogs each were killed at 1, 4, and 8 weeks after the final injection. All dogs tolerated the procedure well and lived until they were killed. The platelet count and leukocyte count increased after the injections, and remained higher than the pretreatment level until death. This effect probably is due to depressed splenic function. The autopsy showed 40% of the spleen to be infarcted with complete destruction of the normal structure. No serious complications occurred. In addition, injection of ethanolamine oleate in six fully heparinized dogs showed that there was little risk of hemorrhage. Ultrasound-guided percutaneous injection of ethanolamine oleate might be a simple and effective therapy for hypersplenism.


Assuntos
Hiperesplenismo/tratamento farmacológico , Ácidos Oleicos/uso terapêutico , Administração Cutânea , Animais , Cães , Ácidos Oleicos/administração & dosagem , Ultrassonografia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA