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1.
EMBO J ; 20(10): 2349-56, 2001 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-11350923

RESUMO

The importance of voltage-dependent Ca2+ channels (VDCCs) in pain transmission has been noticed gradually, as several VDCC blockers have been shown to be effective in inhibiting this process. In particular, the N-type VDCC has attracted attention, because inhibitors of this channel are effective in various aspects of pain-related phenomena. To understand the genuine contribution of the N-type VDCC to the pain transmission system, we generated mice deficient in this channel by gene targeting. We report here that mice lacking N-type VDCCs show suppressed responses to a painful stimulus that induces inflammation and show markedly reduced symptoms of neuropathic pain, which is caused by nerve injury and is known to be difficult to treat by currently available therapeutic methods. This finding clearly demonstrates that the N-type VDCC is essential for development of neuropathic pain and, therefore, controlling the activity of this channel can be of great importance for the management of neuropathic pain.


Assuntos
Ácido Acético/imunologia , Canais de Cálcio Tipo N/fisiologia , Formaldeído/imunologia , Dor/fisiopatologia , Ácido Acético/administração & dosagem , Ácido Acético/efeitos adversos , Estimulação Acústica , Animais , Ansiedade/etiologia , Comportamento Animal , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio Tipo N/genética , Formaldeído/administração & dosagem , Formaldeído/efeitos adversos , Gânglios Espinais/citologia , Marcação de Genes , Hiperalgesia/fisiopatologia , Camundongos , Camundongos Knockout , Atividade Motora , Neurônios/efeitos dos fármacos , Nociceptores , Dor/etiologia , Substância Cinzenta Periaquedutal/metabolismo , Nervos Espinhais/lesões , ômega-Agatoxina IVA/farmacologia
2.
Hum Mol Genet ; 8(7): 1185-93, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10369863

RESUMO

Spinocerebellar ataxia type 6 (SCA6) is one of the eight neurodegenerative diseases caused by a tri-nucleotide (CAG) repeat expansion coding polyglutamine (CAG repeat/polyglutamine diseases) and is characterized by late onset autosomal dominant cerebellar ataxia and predominant loss of cerebellar Purkinje cells. Although the causative, small and stable CAG repeat expansion for this disease has been identified in the [alpha]1A voltage-dependent calcium channel gene (CACNA1A), the mechanism which leads to predominant Purkinje cell degeneration is totally unknown. In this study, we show that the calcium channel mRNA/protein containing the CAG repeat/polyglutamine tract is most intensely expressed in Purkinje cells of human brains. In SCA6 brains, numerous oval or rod-shaped aggregates were seen exclusively in the cytoplasm of Purkinje cells. These cytoplasmic inclusions were not ubiquitinated, which contrasts with the neuronal intra-nuclear inclusions of other CAG repeat/polyglutamine diseases. In cultured cells, formation of perinuclear aggregates of the channel protein and apoptotic cell death were seen when transfected with full-length CACNA1A coding an expanded polyglutamine tract. The present study indicates that the mechanism of neurodegeneration in SCA6 is associated with cytoplasmic aggregations of the [alpha]1A calcium channel protein caused by a small CAG repeat/polyglutamine expansion in CACNA1A.


Assuntos
Encéfalo/metabolismo , Canais de Cálcio/biossíntese , Degenerações Espinocerebelares/metabolismo , Animais , Apoptose , Encéfalo/patologia , Canais de Cálcio/genética , Células Cultivadas , Citoplasma/metabolismo , Humanos , Células PC12 , Peptídeos/metabolismo , Células de Purkinje , RNA Mensageiro/biossíntese , Ratos , Degenerações Espinocerebelares/genética , Degenerações Espinocerebelares/patologia , Expansão das Repetições de Trinucleotídeos/genética
3.
Biochem Biophys Res Commun ; 258(2): 358-65, 1999 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-10329392

RESUMO

Cationic liposome-mediated in vivo gene transfer represents a promising approach for somatic gene therapy. To assess the most suitable liposome for gene delivery into a wide range of organs and fetuses in mice, we have explored several types of cationic liposomes conjugated with plasmid DNA carrying the beta-galactosidase gene through intravenous injection into pregnant animals. Transduction efficiency was assessed by Southern blot analysis and expression of the transferred gene was evaluated by enzymatic demonstration of beta-galactosidase activity. Through the analysis of several types of recently synthesized cationic liposome/lipid formulations, DMRIE-C reagent, a liposome formulation of the cationic lipid DMRIE (1, 2-dimyristyloxypropyl-3-dimethyl-hydroxy ethyl ammonium bromide) and cholesterol in membrane-filtered water met our requirements. When the plasmid DNA/DMRIE-C complexes were administered intravenously into pregnant mice at day 11.5 post coitus (p.c.), transferred genes were observed in several organs in dams and were expressed. Furthermore, although the copy numbers transferred into embryos were low, we observed reporter gene expression in the progeny.


Assuntos
Técnicas de Transferência de Genes , Lipossomos , Animais , Cátions , DNA , Estudos de Avaliação como Assunto , Feminino , Expressão Gênica , Lipídeos , Masculino , Camundongos , Camundongos Endogâmicos ICR , Plasmídeos , Gravidez , Compostos de Amônio Quaternário , beta-Galactosidase/genética
4.
Anticancer Res ; 19(5A): 3779-82, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10625958

RESUMO

The influence of ethyl 3-(4'-geranyloxy-3'-methoxyphenyl)-2-propenoate (EGMP) on the initiation and post-initiation stages of colon carcinogenesis was investigated in male F344 rats treated with azoxymethane (AOM). In experimental protocol 1, EGMP was given in the diet at 0.1 or 0.2% for 1 week together with two s.c. 15 mg/kg body weight injections of AOM on days 1 and 7 (initiation period). In protocol 2, the test compound was administered starting at week 3(post initiation stage), and in protocol 3, the test compound was given throughout the experimental period(whole stage). Sacrifice and quantitation of aberrant crypt foci (ACF) was performed at the end of week 5. Dose-dependent decreases in numbers of ACF were noted with both cases of post-initiation and whole period exposure (protocol 2 and 3), large size lesions considered most likely to be precursor lesions also being significantly reduced in the protocol 2(4-9 crypt size total with the 0.2% dose group, 48.9% and 59.6% of control values, respectively). No effects on body or liver weights were evident. The present results thus suggest that EGMP might find application as a chemopreventive agent against colon tumor development.


Assuntos
Anticarcinógenos/uso terapêutico , Neoplasias do Colo/prevenção & controle , Lesões Pré-Cancerosas/prevenção & controle , Terpenos/uso terapêutico , Animais , Azoximetano/toxicidade , Neoplasias do Colo/induzido quimicamente , Masculino , Ratos , Ratos Endogâmicos F344
5.
Adv Exp Med Biol ; 443: 273-84, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9781370

RESUMO

The influence of bovine lactoferrin (bLf) on colon carcinogenesis was investigated in male F344 rats treated with azoxymethane (AOM). In experiment I, 2% and 0.2% bLf, and Bifidobacterium longum (B. longum) as a positive control at 3% were given in the diet for 4 weeks, along with two s.c. 15 mg/kg injections of AOM on days 1 and 8. The numbers of aberrant crypt foci (ACF) were decreased by both treatments. Similar results were obtained in experiment II of 13 weeks duration. In experiment III, animals were given three weekly injections of AOM and then received 2 or 0.2% bLf, 2% bLf-hydrolysate, or 0.1% bovine lactoferricin (bLfcin) for 36 weeks. No effects indicative of toxicity were noted, but significant reduction in both the incidence and number of adenocarcinomas of the large intestine was observed with almost all the treatments. Thus, the incidences of colon adenocarcinomas in the groups receiving 2 or 0.2% bLf, 2% bLf-hydrolysate, or 0.1% bLfcin were 15%, 25%, 26.3% and only 10%, respectively, in contrast to the 57.5% control value (p < 0.01). ACF values also exhibited reduced development. Investigation of beta-glucuronidase revealed decrease in the cecal contents of animals receiving bLf. In addition, demonstration of enhancement of NK activity by bLf indicated that its inhibitory effects could have been related to elevated immune cytotoxicity.


Assuntos
Colo/efeitos dos fármacos , Neoplasias do Colo/prevenção & controle , Lactoferrina/administração & dosagem , Neoplasias Experimentais/prevenção & controle , Lesões Pré-Cancerosas/prevenção & controle , Animais , Azoximetano/toxicidade , Carcinógenos/toxicidade , Bovinos , Colo/patologia , Neoplasias do Colo/induzido quimicamente , Masculino , Neoplasias Experimentais/induzido quimicamente , Lesões Pré-Cancerosas/induzido quimicamente , Ratos , Ratos Endogâmicos F344
6.
Oncogene ; 16(24): 3189-96, 1998 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-9671398

RESUMO

Embryonic stem (ES) cells are pluripotent cell lines established directly from the early embryo. Maintenance of the stem-cell phenotype of ES cells in vitro requires the presence of a feeder layer of fibroblasts or of a soluble factor, differentiation inhibitory activity (DIA) such as leukemia inhibitory factor (LIF). Here we report the cloning of complete rat LIF cDNA and its nucleotide sequence so as to facilitate studies of rat ES cell technologies on tumor biology. The nucleotide sequence of the rat LIF cDNA indicated that the rat LIF has 91% amino acid sequence identity with murine LIF. The cloned rat LIF cDNA has a putative biological activity as a differentiation-inducing factor on the murine myeloid leukemia cell line M1 cells. Culture supernatant of the rat LIF cDNA-transduced rat fibroblast cell line could maintain the stem-cell phenotype of rat ES cells which showed alkaline phosphatase activity, and this effect was much stronger than that by murine LIF. The availability of rat LIF which shows DIA will assist the in vitro analysis of rat ES cells, and culture of these cells is a route for the generation of gene targeting in rat.


Assuntos
Embrião de Mamíferos/citologia , Inibidores do Crescimento/genética , Interleucina-6 , Linfocinas/genética , Células-Tronco/citologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , DNA Complementar , Feminino , Fator Inibidor de Leucemia , Camundongos , Dados de Sequência Molecular , Gravidez , RNA Mensageiro/genética , Ratos , Ratos Endogâmicos F344 , Células Tumorais Cultivadas
7.
Cancer Lett ; 127(1-2): 9-13, 1998 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-9619852

RESUMO

Deletion of 9p21 has frequently been observed in human bladder carcinomas. A candidate target suppressor gene, p16, was recently identified within this deleted region. In this study, we therefore investigated the loss of heterozygosity (LOH) of the p16 gene which is located on mouse chromosome 4, as well as its expression in mouse bladder carcinomas. We also studied the effects of normal cell contamination on LOH analysis using xenografts in CD-1(ICR) nude mice from B6C3F1 bladder carcinomas. We could not detect any LOH at the p16 locus in the mouse primary bladder carcinomas and xenografts. Surprisingly, overexpression of p16 was found in all primary mouse bladder carcinomas. Using microsatellite polymorphisms, a distinction could be made between PCR products derived from B6C3F1 and CD-1(ICR) nude mice. It was thereby confirmed that effects of normal cell contamination on LOH analysis are negligible when only tumor tissue is carefully sampled. The results suggest that abnormalities of p16 expression may be involved in mouse bladder carcinogenesis, but that gene deletion is not involved.


Assuntos
Genes p16 , Perda de Heterozigosidade , Neoplasias da Bexiga Urinária/genética , Animais , Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos ICR , Transplante de Neoplasias
8.
Carcinogenesis ; 19(1): 81-5, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9472697

RESUMO

The present study was carried out to examine the chemopreventive effects of carotenoids such as fucoxanthin, lycopene and lutein as well as curcumin and its derivative, tetrahydrocurcumin (THC), on development of putative preneoplastic aberrant crypt foci (ACF) in colons of mice initiated with 1,2-dimethylhydrazine dihydrochloride (DMH). Influence on proliferation of colonic crypt epithelial cells was also assessed in terms of 5-bromo-2'-deoxyuridine (BrdU) incorporation. Five-week-old B6C3F1 male mice were divided into three groups, groups 1 and 2 being given DMH (20 mg/kg body wt, s.c.) twice a week for 3 weeks. Animals of group 1 were then treated with one of the test compounds, lycopene (0.005% and 0.0025%) or fucoxanthin (0.01%) in the drinking water and lutein (0.05%), curcumin (0.5%) or THC (0.5% and 0.2%) in the diet from weeks 5-12. Group 2 served as a carcinogen alone control and group 3 mice were given test compounds alone. All animals were killed at week 12. Numbers of ACF/mouse in the group 1 treated with fucoxanthin (47.1 +/- 13.7), lutein (42.6 +/- 19.6) or 0.5% THC (46.6 +/- 17.7) were significantly decreased as compared to the control group 2 value (63.3 +/- 19.4) (P < 0.01). Numbers of aberrant crypts (ACs)/mouse were also significantly lower after treatment with lutein (79.9 +/- 34.7) or 0.5% THC (81.8 +/- 32.5) than in the control group (115.1 +/- 37.1) (P < 0.01). BrdU labeling indices (LI) in mice treated with lutein and 0.5% THC were significantly decreased in both upper and lower half compartments of colonic crypts as compared to the controls (P < 0.05 and 0.01, respectively), especially the upper half data corresponding to reduction of ACs/mouse. The results thus suggest that fucoxanthin, lutein, and THC may have potential as chemopreventive agents against colon carcinogenesis.


Assuntos
1,2-Dimetilidrazina , Anticarcinógenos/uso terapêutico , Carcinógenos , Carotenoides/uso terapêutico , Colo/efeitos dos fármacos , Neoplasias do Colo/prevenção & controle , Curcumina/uso terapêutico , Mucosa Intestinal/efeitos dos fármacos , Animais , Divisão Celular/efeitos dos fármacos , Colo/citologia , Colo/patologia , Neoplasias do Colo/induzido quimicamente , Curcumina/análogos & derivados , Mucosa Intestinal/citologia , Mucosa Intestinal/patologia , Masculino , Camundongos , Camundongos Endogâmicos
9.
Jpn J Cancer Res ; 88(6): 523-6, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9263527

RESUMO

The influence of bovine lactoferrin (bLF) on colon carcinogenesis was investigated in male F344 rats treated with azoxymethane (AOM). Following three weekly injections of AOM, the animals received 2 or 0.2% bLF for 36 weeks. No effects indicative of toxicity were noted, but significant reduction in both the incidence and number of adenocarcinomas of the large intestine was observed with both doses. Thus, the incidences of adenocarcinomas in the groups receiving 2% and 0.2% bLF were 15% and 25%, respectively, in contrast to the 57.5% control value (P < 0.01 and P < 0.05, respectively). The results indicate that bLF might find application for chemoprevention of colon cancer.


Assuntos
Adenocarcinoma/prevenção & controle , Anticarcinógenos/farmacologia , Azoximetano/toxicidade , Neoplasias do Colo/prevenção & controle , Neoplasias Intestinais/prevenção & controle , Lactoferrina/farmacologia , Adenocarcinoma/induzido quimicamente , Adenocarcinoma/patologia , Adenoma/induzido quimicamente , Adenoma/patologia , Adenoma/prevenção & controle , Animais , Azoximetano/antagonistas & inibidores , Carcinoma/induzido quimicamente , Carcinoma/patologia , Carcinoma/prevenção & controle , Bovinos , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/patologia , Incidência , Neoplasias Intestinais/induzido quimicamente , Neoplasias Intestinais/patologia , Intestino Grosso/patologia , Intestino Delgado/patologia , Masculino , Ratos , Ratos Endogâmicos F344
10.
Cancer Lett ; 121(2): 211-6, 1997 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-9570361

RESUMO

The influence of concomitant administration of bovine lactoferrin (bLF) on induction of aberrant crypt foci (ACF) by azoxymethane was investigated in male F344 rats. Two percent bLF and 3% Bifidobacterium longum (B. longum), as a positive control, significantly decreased the numbers of ACF as well as the total numbers of aberrant crypts reproducibly in three independent studies (2% bLF, P < 0.01; 3% B. longum, P < 0.05). Most importantly large size foci composed of four or more crypts were always significantly decreased by 2% bLF (P < 0.05). Additional investigation of the natural killer activity of spleen cells demonstrated enhancement by bLF (P < 0.01) and B. longum (P < 0.01) in line with the levels of influence on foci induction, indicating a possible role for elevated immune cytotoxicity in the observed inhibition.


Assuntos
Anticarcinógenos/uso terapêutico , Azoximetano/toxicidade , Carcinógenos/toxicidade , Neoplasias do Colo/prevenção & controle , Células Matadoras Naturais/imunologia , Lactoferrina/uso terapêutico , Animais , Bifidobacterium/fisiologia , Quimioprevenção , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/imunologia , Esquema de Medicação , Masculino , Estadiamento de Neoplasias , Lesões Pré-Cancerosas/induzido quimicamente , Lesões Pré-Cancerosas/imunologia , Lesões Pré-Cancerosas/prevenção & controle , Ratos , Ratos Endogâmicos F344
11.
Carcinogenesis ; 17(11): 2441-8, 1996 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8968061

RESUMO

Two different types of focal preneoplastic lesions, tentatively named Type I and II lesions, were recognized in the liver of rats chronically treated with clofibrate for 104 weeks. Type I lesions were characterized by mostly negative glucose-6-phosphate dehydrogenase (G6PD) activity (6 out of 10, 60%) and positive expression of succinate dehydrogenase (10 out of 10, 100%), in addition to the previously documented complete lack of expression of glutathione S-transferase, placental form (GST-P) and gamma-glutamyl transpeptidase (GGT). Furthermore, most importantly, Type I lesions exhibited a clear decrease in immunohistochemically demonstrated connexin32 (Cx32) spot counts on their hepatocyte membranes, similarly to nitrosamine-induced lesions. In contrast, Type II lesions, mostly small in size and positively expressing GST-P and/or GGT and G6PD, similarly to their previously reported nitrosamine-induced counterparts, did not exhibit a significant decrease in Cx32 count. In addition, spontaneously occurring lesions, again sharing the same enzyme phenotype, did not show a decrease in Cx32. The results indicate that: (i) a clear distinction between the two lesions, with Type I being involved in clofibrate-induced tumors and Type II being more likely to be spontaneous in nature; (ii) a decrease in Cx32 is closely linked to lesion development and possibly stage of progression, irrespective of the enzyme phenotype and the applied carcinogen; (iii) the unaltered condition of Cx32 may suggest a slow growing or non-progressive nature.


Assuntos
Carcinógenos/toxicidade , Clofibrato/toxicidade , Conexinas/metabolismo , Neoplasias Hepáticas Experimentais/induzido quimicamente , Neoplasias Hepáticas Experimentais/enzimologia , Lesões Pré-Cancerosas/induzido quimicamente , Lesões Pré-Cancerosas/enzimologia , Animais , Dietilnitrosamina/análogos & derivados , Dietilnitrosamina/toxicidade , Glutationa Transferase/metabolismo , Neoplasias Hepáticas Experimentais/metabolismo , Masculino , Microcorpos/efeitos dos fármacos , Fenótipo , Lesões Pré-Cancerosas/metabolismo , Ratos , Ratos Wistar , gama-Glutamiltransferase/metabolismo , Proteína beta-1 de Junções Comunicantes
12.
Jpn J Cancer Res ; 87(6): 549-54, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8766516

RESUMO

The modifying effects of dietary administration of 6-(2,5-dichlorophenyl)-2,4-diamino-1,3,5-triazine and 5 related compounds on the occurrence of azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) were investigated in rats. Male F344 rats were given s.c. injections of AOM (15 mg/kg body weight) once a week for 3 weeks to induce ACF. They also received the diet containing 200 ppm test compound for 5 weeks, starting one week before the first dosing of AOM. At the termination of experiment, all of the compounds had caused a significant reduction in ACF frequency, which might be associated with suppression of the expression of proliferation biomarkers. The apoptotic index in the colonic mucosal epithelium of rats killed at 6 h after the first AOM exposure revealed no blocking activity of the compounds.


Assuntos
Anticarcinógenos/uso terapêutico , Azoximetano , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/prevenção & controle , Lesões Pré-Cancerosas/induzido quimicamente , Lesões Pré-Cancerosas/prevenção & controle , Triazinas/uso terapêutico , Animais , Anticarcinógenos/administração & dosagem , Apoptose , Neoplasias do Colo/patologia , Dieta , Epitélio/patologia , Mucosa Intestinal/patologia , Masculino , Ornitina Descarboxilase/metabolismo , Poliaminas/sangue , Lesões Pré-Cancerosas/patologia , Ratos , Ratos Endogâmicos F344 , Triazinas/administração & dosagem
13.
Jpn J Cancer Res ; 87(4): 342-8, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8641964

RESUMO

To assess mechanisms of chemoprevention of hepatocarcinogenesis by trans-beta-carotene (beta-C), DL-alpha-tocopherol (alpha-T), and freeze-dried whole leaves of Kidachi aloe (Aloe), formation of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ)-DNA adducts was measured by 32P-post-labeling analysis, and CYP1A1 and CYP1A2 protein levels were analyzed by ELISA. Group 1 rats were fed diet containing 0.02% beta-C, 1.5% alpha-T or 30% Aloe over an 8-day period, while group 2 was given basal diet alone. On day 7, all animals were subjected to two-thirds partial hepatectomy (PH). Twelve hours after PH, they received a single dose of the carcinogenic food pyrolysate IQ (100 mg/kg) intragastrically, to initiate hepatocarcinogenesis. Rats were killed 6, 12, 24 and 48 h after IQ administration. The levels of adducts, expressed as relative adduct labeling values in rats treated with beta-C, alpha-T and Aloe, were decreased as compared with the control group at hour 24 (36 h after PH), with a significant difference in the case of the beta-C group (46.4% of the control value). Similarly, all showed a tendency for decrease at hour 48. Furthermore, the levels of CYP1A2, known to be responsible for activation of IQ, showed a significant reduction at hour 24. It is concluded that beta-C, and possibly also alpha-T and Aloe, have the potential to reduce IQ-DNA adduct formation, presumably as a result of decreased formation of active metabolites. The results may explain, at least in part, the previously observed inhibitory effects of these compounds on induction of preneoplastic hepatocellular lesions.


Assuntos
Aloe , Antimutagênicos/farmacologia , Carotenoides/farmacologia , Adutos de DNA/metabolismo , Mutagênicos/metabolismo , Mutagênicos/toxicidade , Plantas Medicinais , Quinolinas/metabolismo , Quinolinas/toxicidade , Vitamina E/farmacologia , Animais , Biotransformação , Citocromo P-450 CYP1A2 , Sistema Enzimático do Citocromo P-450/metabolismo , DNA/efeitos dos fármacos , DNA/metabolismo , Dano ao DNA , Liofilização , Isoenzimas/metabolismo , Masculino , Mutagênicos/farmacocinética , Oxirredutases/metabolismo , Quinolinas/farmacocinética , Ratos , Ratos Endogâmicos F344 , beta Caroteno
14.
Jpn J Cancer Res ; 87(3): 240-6, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8613425

RESUMO

Modifying effects of fibrosis or a cirrhotic state, caused by treatment with swine serum (SS), on the induction of preneoplastic focal lesions were assessed in a rat medium-term liver bioassay model for the detection of environmental carcinogens, in which the test compound is administered during the promotion phase after initiation with diethylnitrosamine. In experiment I, repeated intraperitoneal administration of SS concomitantly with the hepatopromoting agent deoxycholic acid (DCA) or phenobarbital (PB) resulted in a cirrhotic state and a significant increase in the number or size of preneoplastic glutathione S-transferase placental form (GST-P)-positive liver cell foci as compared to the corresponding DCA or PB alone groups. In experiment II, SS was given prior to commencement of the same medium-term bioassay system, in which a known hepatopromoting agent, DCA, 17-alpha-ethynylestradiol, or 2-acetylaminofluorene, was applied. In this case, the liver did not show obvious cirrhotic change and, rather than any enhancement, slight inhibition of promotion occurred. The results indicate that a coexisting, but not a pre-existing, cirrhotic condition acts to increase growth pressure on GST-P+ preneoplastic foci, and suggest that concomitant administration of SS with the promoting agent could be applied to improve the sensitivity of the assay protocol.


Assuntos
Sangue , Cocarcinogênese , Cirrose Hepática Experimental/complicações , Hepatopatias/etiologia , Lesões Pré-Cancerosas/etiologia , 2-Acetilaminofluoreno/toxicidade , Animais , Doença Hepática Induzida por Substâncias e Drogas , Ácido Desoxicólico/toxicidade , Etinilestradiol/toxicidade , Glutationa Transferase/análise , Injeções Intraperitoneais , Fígado/efeitos dos fármacos , Fígado/enzimologia , Fígado/patologia , Masculino , Tamanho do Órgão/efeitos dos fármacos , Fenobarbital/toxicidade , Lesões Pré-Cancerosas/induzido quimicamente , Ratos , Ratos Endogâmicos F344 , Suínos/sangue
15.
IARC Sci Publ ; (139): 143-50, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8923026

RESUMO

Organotropic chemopreventive effects of three (pro)vitamins and three unsaturated fatty acids were examined using mouse and rat multiorgan carcinogenesis models. For the study of (pro)vitamins, male and female B6C3F1 mice were treated with N,N-diethylnitrosamine (DEN) and N-methyl-N-nitrosourea (MNU) during the first 11 weeks, then from weeks 12 to 32 they received alpha-carotene (0.4 mg/mouse), beta-carotene (0.4 mg/mouse) or alpha-tocopherol (40 mg/mouse) three times a week by gavage; control mice received vehicle alone. In male mice, alpha-carotene significantly reduced liver weights, representing a reduced tumour mass (P < 0.001), and alpha-carotene, beta-carotene and alpha-tocopherol significantly reduced the numbers of liver tumours (adenomas and carcinomas combined) (P < 0.001-0.01) as compared with control mice, the effects being greatest with alpha-carotene. In female mice, alpha-carotene significantly decreased the number of liver tumours (P < 0.001). In the lung, alpha-carotene and alpha-tocopherol reduced the area of lesions (hyperplasias and adenomas combined) only in males (P < 0.05). For the study of unsaturated fatty acids, F344 male rats were treated with DEN, MNU, N-butyl-N-hydroxybutylnitrosamine (BBN), 1,2-dimethylhydrazine (DMH) and N,N-bis(2-hydroxy)propylnitrosamine during the first 5 weeks, then from weeks 6 to 36 they were given docosahexaenoic acid (C22:6), eicosapentaenoic acid (C20:5) or linoleic acid (C18:2) at 1.0 g/rat, three times a week by gavage; control rats were treated with oleic acid (C18:1) using the same protocol. All animals were fed a low linoleic acid and calorie-adjusted basal diet during fatty acid administration. Docosahexaenoic acid and linoleic acid reduced tumours in the large and small intestines, respectively. However, they did not influence the yield of preneoplastic liver, lung, kidney, forestomach and urinary bladder lesions. The data thus provide evidence for organotropic effects of carotenoids and unsaturated fatty acids on carcinogenesis.


Assuntos
Anticarcinógenos/uso terapêutico , Ácidos Graxos Insaturados/uso terapêutico , Neoplasias Hepáticas Experimentais/prevenção & controle , Neoplasias Pulmonares/prevenção & controle , Vitaminas/uso terapêutico , Animais , Carcinógenos , Modelos Animais de Doenças , Feminino , Fígado/anatomia & histologia , Fígado/efeitos dos fármacos , Neoplasias Hepáticas Experimentais/induzido quimicamente , Neoplasias Pulmonares/induzido quimicamente , Masculino , Camundongos , Camundongos Endogâmicos , Tamanho do Órgão/efeitos dos fármacos , Especificidade de Órgãos , Ratos , Ratos Endogâmicos F344
16.
Acta Neurochir (Wien) ; 138(10): 1218-22; discussion 1222-3, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8955442

RESUMO

Ischaemic cerebral strokes in children are relatively uncommon. With the exception of patients with moyamoya disease, there is no effective treatment for these lesions. One potential approach is encephalo-duro-arterio-synangiosis (EDAS). This is a safe neurosurgical procedure that promotes spontaneous transdural anastomosis that may provide additional blood flow to ischaemic regions. We present eight children with ischaemic strokes other than moyamoya disease, and discuss surgical attempts to treat this entity. The mean age of the eight children was 3.6 years (range: 13 months to 9 years). All children presented with acute childhood hemiplegia. Ischaemic stroke had occurred in association with a head injury in three children, but without an apparent cause in five. Five children underwent stable xenon-enhanced computed tomography to evaluate cerebral blood flow and all but one patient underwent EDAS. One child with no angiographic abnormalities recovered to a normal neurological state without surgery. Following surgery, another child also fully recovered, and the remaining six children recovered with only a slight hemiparesis. Revascularization was observed on a follow-up angiogram in three children. Our surgical experiences suggest that revascularization is influenced by haemodynamic demand and recanalization of the occluded artery. We favour the use of indirect anastomosis (EDAS) for selected patients and suggest that chronic ischaemia probably contributes to surgical success.


Assuntos
Isquemia Encefálica/cirurgia , Revascularização Cerebral , Transtornos Cerebrovasculares/cirurgia , Anastomose Cirúrgica , Artérias/cirurgia , Isquemia Encefálica/etiologia , Angiografia Cerebral , Transtornos Cerebrovasculares/etiologia , Criança , Pré-Escolar , Dominância Cerebral/fisiologia , Dura-Máter/irrigação sanguínea , Feminino , Humanos , Lactente , Masculino , Doença de Moyamoya/cirurgia , Exame Neurológico , Complicações Pós-Operatórias/diagnóstico , Tomografia Computadorizada por Raios X
17.
Toxicol Lett ; 82-83: 693-9, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8597128

RESUMO

Altered enzyme phenotype and expression of connexin 32 (Cx32), a gap junction protein were studied during the development of rat liver tumors induced by the non-genotoxic carcinogen, clofibrate. (1) In contrast to previous findings for nitrosamine-induced lesions, preneoplastic enzyme-altered foci (EAF) and neoplastic nodules (NN) lacked any clear association with degree of altered enzyme expression because of an almost complete negativity for GST-P and GGT. (2) Immunohistochemically demonstrated Cx32 spots on the hepatocyte membranes showed a clear decrease in clofibrate-induced lesions. (3) Naturally occurring EAF demonstrating GST-P and/or GGT positivity did not show a significant decrease of Cx32 counts suggesting a reversible nature. Therefore, the Cx32 decrease appears closely linked to progression of hepatocarcinogenesis irrespective of the enzyme phenotype of neoplastic focal lesions and the carcinogens used for their induction.


Assuntos
Clofibrato/toxicidade , Conexinas/análise , Neoplasias Hepáticas Experimentais/induzido quimicamente , Lesões Pré-Cancerosas/induzido quimicamente , Animais , Junções Comunicantes/fisiologia , Fígado/química , Fígado/enzimologia , Neoplasias Hepáticas Experimentais/enzimologia , Masculino , Lesões Pré-Cancerosas/enzimologia , Ratos , Ratos Wistar , Proteína beta-1 de Junções Comunicantes
18.
Jpn J Surg ; 21(3): 268-71, 1991 May.
Artigo em Inglês | MEDLINE | ID: mdl-1857031

RESUMO

It is widely accepted that patients with aortic aneurysm (AA) show a higher incidence of peptic ulcers than those without. However, the pathogenesis of peptic ulcers associated with AA remains obscure. We measured the gastric mucosal blood flow (GMBF) endoscopically and also determined the gastric mucosal prostaglandin (PG) levels of these AA patients to investigated the mechanism behind gastric ulcer formation. Moreover, we investigated the consumption coagulopathy (CC) of AA responsible for inducing the hemorrhage from ulcers. The GMBF values of 7 AA cases, taken at the antrum, angle and corpus, were significantly decreased compared with those of control cases, while the PGE2 levels of the gastric mucosa were also significantly reduced. With regard to CC, the serum levels of fibrinogen or platelets were significantly lower than those of the control group. These results indicate that the decrease in GMBF, followed by the reduction in endogenous PG, might contribute to the gastric ulcer formation in AA patients, and that CC associated with AA could be an important factor causing the hemorrhage from these ulcers. AA patients should therefore be treated with focusing attention on the possibility of an associated ulcer and ulcer bleeding.


Assuntos
Aneurisma Aórtico/complicações , Mucosa Gástrica/irrigação sanguínea , Úlcera Péptica Hemorrágica/etiologia , Úlcera Péptica/etiologia , Idoso , Aneurisma Aórtico/fisiopatologia , Dinoprostona/metabolismo , Coagulação Intravascular Disseminada/etiologia , Coagulação Intravascular Disseminada/fisiopatologia , Endoscopia Gastrointestinal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Úlcera Péptica/fisiopatologia , Úlcera Péptica Hemorrágica/fisiopatologia , Prostaglandinas F/metabolismo , Fluxo Sanguíneo Regional
19.
Gan To Kagaku Ryoho ; 16(1): 53-8, 1989 Jan.
Artigo em Japonês | MEDLINE | ID: mdl-2783545

RESUMO

The human recombinant interleukin 2 (IL-2) was entrapped in liposomes, and the therapeutic effects of the liposomes containing IL-2 (Lip-IL-2) were experimentally studied using the rat hepatoma strain, AH-66, maintained in donryu rats and challenged subcutaneously in the inguinal region. The peri-tumor injections of Lip-IL-2 (15 X 10(4)/kg units for the IL-2 dose) significantly inhibited the tumor growth as determined from the relative mean tumor weight, although no therapeutic effects were observed when the unentrapped IL-2 or liposomes containing saline was administered rats in the same way as the injections of Lip-IL-2. They also prolonged the survival time of rats. The studies of serum IL-2 values after i.v. or s.c. injections of Lip-IL-2 revealed that IL-2 was released gradually from the liposomes containing IL-2 into the circulation. As the result of the tumor tissue staining of the immunoperoxidase 18 hrs after the peri-tumor injection of IL-2, it was shown that a number of macrophages infiltrated into the tumor tissue and degenerated tumor cells were observed adjacent to those macrophages. It is suggested that Lip-IL-2 is useful as an antineoplastic agent in the immunotherapy and that the therapeutic effects of Lip-IL-2 would be related to both the slow release of IL-2 and the cytotoxicity on the tumor cells mediated by the macrophages.


Assuntos
Interleucina-2/administração & dosagem , Neoplasias Hepáticas Experimentais/terapia , Animais , Portadores de Fármacos , Avaliação de Medicamentos , Interleucina-2/farmacocinética , Interleucina-2/uso terapêutico , Lipossomos , Neoplasias Hepáticas Experimentais/mortalidade , Neoplasias Hepáticas Experimentais/patologia , Macrófagos/patologia , Masculino , Ratos , Ratos Endogâmicos , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/farmacocinética , Proteínas Recombinantes/uso terapêutico
20.
Gan To Kagaku Ryoho ; 15(5): 1791-3, 1988 May.
Artigo em Japonês | MEDLINE | ID: mdl-3369874

RESUMO

Two years and 10 months after gastrectomy, a 38-year-old man was diagnosed as having carcinomatous peritonitis due to gastric cancer. He was treated by intra-abdominal administration of 100 mg CDDP three times in addition to UFT. After each administration of CDDP, the amount of ascites and the serum value of CEA were decreased. Subjective symptoms, such as epigastric pain or sensation of fullness, were also improved. Although one year and 8 months has passed since the first administration of CDDP, the performance status of the patient remains 0. Nausea or vomiting was noted within 2 days after each administration. However, severe complications, like renal failure or intra-abdominal hemorrhage, were not observed. These findings suggest that repeated intra-abdominal administration of CDDP may be a useful therapy for carcinomatous peritonitis due to gastric cancer.


Assuntos
Adenocarcinoma/complicações , Cisplatino/administração & dosagem , Peritonite/tratamento farmacológico , Neoplasias Gástricas/complicações , Adenocarcinoma/cirurgia , Adulto , Gastrectomia , Humanos , Masculino , Complicações Pós-Operatórias/tratamento farmacológico , Neoplasias Gástricas/cirurgia
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