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1.
Ann Ig ; 34(1): 13-26, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34113955

RESUMO

Background: Understanding the level of awareness in adolescents on the value of vaccination is kay to developing a proper culture of prevention to counter vaccine hesitancy and the decrease in vaccination coverages. Study design: The aim of the survey was to evaluate awareness, attitudes, opinions, skills and knowledge about vaccines in a group of Italian adolescents through a paper-and-pencil questionnaire. Methods: The questionnaire was administered to adolescents who had appointments in two vaccination centers of the Public Health Authority of Latina (Latium, Italy), between August 2018 and January 2019. Results: In total, 391 forms were completed by teenagers (median age 16 years, 52% females), Results showed that 53% of participants were not aware of their vaccination status. Knowledge, assessed through questions about vaccines and preventable diseases, was generally poor. However, 89% of adolescents had a positive opinion about vaccinations. Spontaneous searches for vaccine information was low (28.7% had looked for information), despite the medium to high interest expressed. The participants usually sought information on vaccines on generic websites (52.8%) compared to getting information from paediatricians (20.4%) or other physicians (3.7%). However, participants recognized paediatricians/GPs (47%) and schools (46.2%) as the most reliable sources of information. Conclusions: Findings are in agreement with previous published data and can be useful to school and health educators in order to teach adolescents about the value of prevention, providing them with the support necessary to improve their abilities and knowledge.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Vacinas , Adolescente , Feminino , Humanos , Itália , Masculino , Inquéritos e Questionários , Vacinação
2.
Reumatismo ; 67(2): 45-56, 2015 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-26492962

RESUMO

The aim of the study is to estimate the pension costs incurred for patients with musculoskeletal disorders (MDs) and specifically with rheumatoid arthritis (RA) and ankylosing spondylitis (AS) in Italy between 2009 and 2012. We analyzed the database of the Italian National Social Security Institute (Istituto Nazionale Previdenza Sociale i.e. INPS) to estimate the total costs of three types of social security benefits granted to patients with MDs, RA and AS: disability benefits (for people with reduced working ability), disability pensions (for people who cannot qualify as workers) and incapacity pensions (for people without working ability). We developed a probabilistic model with a Monte Carlo simulation to estimate the total costs for each type of benefit associated with MDs, RA and AS. We also estimated the productivity loss resulting from RA in 2013. From 2009 to 2012 about 393 thousand treatments were paid for a total of approximately €2.7 billion. The annual number of treatments was on average 98 thousand and cost in total €674 million per year. In particular, the total pension burden was about €99 million for RA and €26 million for AS. The productivity loss for AR in 2013 was equal to €707,425,191 due to 9,174,221 working days lost. Our study is the fi rst to estimate the burden of social security pensions for MDs based on data of both approved claims and benefits paid by the national security system. From 2009 to 2012, in Italy, the highest indirect costs were associated with disability pensions (54% of the total indirect cost), followed by disability benefits (44.1% of cost) and incapacity pensions (1.8% of cost). In conclusion, MDs are chronic and highly debilitating diseases with a strong female predominance and very significant economic and social costs that are set to increase due to the aging of the population.


Assuntos
Doenças Musculoesqueléticas/economia , Absenteísmo , Artrite Reumatoide/economia , Artrite Reumatoide/epidemiologia , Efeitos Psicossociais da Doença , Eficiência , Feminino , Gastos em Saúde , Humanos , Seguro por Deficiência , Itália/epidemiologia , Masculino , Modelos Econômicos , Método de Monte Carlo , Doenças Musculoesqueléticas/epidemiologia , Pensões , Licença Médica , Previdência Social/economia , Espondilite Anquilosante/economia , Espondilite Anquilosante/epidemiologia
4.
Oncogene ; 25(14): 2105-12, 2006 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-16288213

RESUMO

Activating mutations in K-ras are one of the most common genetic alterations in human lung cancer. To dissect the role of K-ras activation in bronchial epithelial cells during lung tumorigenesis, we created a model of lung adenocarcinoma by generating a conditional mutant mouse with both Clara cell secretory protein (CC10)-Cre recombinase and the Lox-Stop-Lox K-ras(G12D) alleles. The activation of K-ras mutant allele in CC10 positive cells resulted in a progressive phenotype characterized by cellular atypia, adenoma and ultimately adenocarcinoma. Surprisingly, K-ras activation in the bronchiolar epithelium is associated with a robust inflammatory response characterized by an abundant infiltration of alveolar macrophages and neutrophils. These mice displayed early mortality in the setting of this pulmonary inflammatory response with a median survival of 8 weeks. Bronchoalveolar lavage fluid from these mutant mice contained the MIP-2, KC, MCP-1 and LIX chemokines that increased significantly with age. Cell lines derived from these tumors directly produced MIP-2, LIX and KC. This model demonstrates that K-ras activation in the lung induces the elaboration of inflammatory chemokines and provides an excellent means to further study the complex interactions between inflammatory cells, chemokines and tumor progression.


Assuntos
Genes ras , Neoplasias Pulmonares/genética , Pneumonia/genética , Animais , Sequência de Bases , Líquido da Lavagem Broncoalveolar , Linhagem Celular Tumoral , Primers do DNA , Humanos , Imuno-Histoquímica , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/fisiopatologia , Macrófagos Alveolares/patologia , Camundongos , Camundongos Mutantes , Pneumonia/complicações , Reação em Cadeia da Polimerase Via Transcriptase Reversa
5.
Mol Biol Cell ; 9(6): 1411-24, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9614183

RESUMO

The mechanisms responsible for the induction of matrix-degrading proteases during lung injury are ill defined. Macrophage-derived mediators are believed to play a role in regulating synthesis and turnover of extracellular matrix at sites of inflammation. We find a localized increase in the expression of the rat interstitial collagenase (MMP-13; collagenase-3) gene from fibroblastic cells directly adjacent to macrophages within silicotic rat lung granulomas. Conditioned medium from macrophages isolated from silicotic rat lungs was found to induce rat lung fibroblast interstitial collagenase gene expression. Conditioned medium from primary rat lung macrophages or J774 monocytic cells activated by particulates in vitro also induced interstitial collagenase gene expression. Tumor necrosis factor-alpha (TNF-alpha) alone did not induce interstitial collagenase expression in rat lung fibroblasts but did in rat skin fibroblasts, revealing tissue specificity in the regulation of this gene. The activity of the conditioned medium was found to be dependent on the combined effects of TNF-alpha and 12-lipoxygenase-derived arachidonic acid metabolites. The fibroblast response to this conditioned medium was dependent on de novo protein synthesis and involved the induction of nuclear activator protein-1 activity. These data reveal a novel requirement for macrophage-derived 12-lipoxygenase metabolites in lung fibroblast MMP induction and provide a mechanism for the induction of resident cell MMP gene expression during inflammatory lung processes.


Assuntos
Araquidonato 12-Lipoxigenase/metabolismo , Colagenases/biossíntese , Fibroblastos/enzimologia , Macrófagos/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Animais , Ácido Araquidônico/metabolismo , Linhagem Celular , Colagenases/genética , Meios de Cultivo Condicionados , Indução Enzimática , Matriz Extracelular/metabolismo , Matriz Extracelular/fisiologia , Expressão Gênica , Cinética , Pulmão/imunologia , Pneumopatias/enzimologia , Lesão Pulmonar , Metaloproteinase 13 da Matriz , Camundongos , Modelos Biológicos , Ratos , Ratos Sprague-Dawley , Silicose/enzimologia , Fator de Transcrição AP-1/metabolismo
6.
J Clin Oncol ; 18(16): 2972-80, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10944130

RESUMO

PURPOSE: A randomized phase III trial was conducted to determine whether combination therapy with 13-cis-retinoic acid (13-CRA) plus interferon alfa-2a (IFNalpha2a) is superior to IFNalpha2a alone in patients with advanced renal cell carcinoma (RCC). PATIENTS AND METHODS: Two hundred eighty-four patients were randomized to treatment with IFNalpha2a plus 13-CRA or treatment with IFNalpha2a alone. IFNalpha2a was given daily subcutaneously, starting at a dose of 3 million units (MU). The dose was escalated every 7 days from 3 to 9 MU (by increments of 3 MU), unless >/= grade 2 toxicity occurred, in which case dose escalation was stopped. Patients randomized to combination therapy were given oral 13-CRA 1 mg/kg/d plus IFNalpha2a. Quality of life (QOL) was assessed. RESULTS: Complete or partial responses were achieved by 12% of patients treated with IFNalpha2a plus 13-CRA and 6% of patients treated with IFNalpha2a (P =.14). Median duration of response (complete and partial combined) in the group treated with the combination was 33 months (range, 9 to 50 months), versus 22 months (range, 5 to 38 months) for the second group (P =.03). Nineteen percent of patients treated with IFNalpha2a plus 13-CRA were progression-free at 24 months, compared with 10% of patients treated with IFNalpha2a alone (P =.05). Median survival time for all patients was 15 months, with no difference in survival between the two treatment arms (P =.26). QOL decreased during the first 8 weeks of treatment, and a partial recovery followed. Lower scores were associated with the combination therapy. CONCLUSION: Response proportion and survival did not improve significantly with the addition of 13-CRA to IFNalpha2a therapy in patients with advanced RCC. 13-CRA may lengthen response to IFNalpha2a therapy in patients with IFNalpha2a-sensitive tumors. Treatment, particularly the combination therapy, was associated with a decrease in QOL.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Renais/tratamento farmacológico , Interferon-alfa/uso terapêutico , Isotretinoína/uso terapêutico , Neoplasias Renais/tratamento farmacológico , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Intervalo Livre de Doença , Feminino , Humanos , Injeções Subcutâneas , Interferon alfa-2 , Interferon-alfa/administração & dosagem , Isotretinoína/administração & dosagem , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Análise Multivariada , Qualidade de Vida , Proteínas Recombinantes , Estatísticas não Paramétricas , Inquéritos e Questionários , Análise de Sobrevida , Resultado do Tratamento
7.
J Clin Oncol ; 18(12): 2413-8, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10856101

RESUMO

PURPOSE: To evaluate the dose, toxicity, and efficacy of paclitaxel in combination with ifosfamide and cisplatin as salvage therapy for patients with relapsed testicular germ cell tumors (GCTs). PATIENTS AND METHODS: Thirty patients with previously treated GCTs were treated with paclitaxel and ifosfamide plus cisplatin (TIP) as second-line therapy. All had favorable prognostic features for response (testis primary tumor site and prior complete response to first-line chemotherapy program). Four cycles of paclitaxel, ifosfamide 5 g/m(2), and cisplatin 100 mg/m(2) were given 21 days apart with granulocyte colony-stimulating factor support, followed by resection of radiographic residua. The dose of paclitaxel was increased among cohorts with dose levels of 175, 215, and 250 mg/m(2); the largest dose was selected for the phase II part of the trial. RESULTS: Twenty-three (77%) of 30 patients achieved a complete response to chemotherapy alone, and one patient achieved a durable partial response with normal tumor markers. Therefore, 24 (80%) achieved a favorable response. Eleven patients with normalized markers after chemotherapy underwent resection of residual tissue, with only necrosis found in 10 and mature teratoma in one. Two patients relapsed, and 22 (73%) of the favorable responses remain durable at a median follow-up duration of 33 months. Myelosuppression was the major toxicity, and two patients had grade 3 neurotoxicity. CONCLUSION: Four cycles of TIP was associated with a high proportion of patients who achieved a complete response, a lack of relapse, and relative tolerability as an ifosfamide-containing salvage regimen for testicular GCTs. The high durable complete response proportion emphasizes the importance of patient selection according to prognostic factors for a favorable outcome to conventional-dose salvage therapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Germinoma/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Neoplasias Testiculares/tratamento farmacológico , Adulto , Cisplatino/administração & dosagem , Esquema de Medicação , Germinoma/patologia , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Humanos , Ifosfamida/administração & dosagem , Masculino , Pessoa de Meia-Idade , Paclitaxel/administração & dosagem , Terapia de Salvação , Taxoides , Neoplasias Testiculares/patologia , Resultado do Tratamento
8.
J Clin Oncol ; 18(6): 1173-80, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10715285

RESUMO

PURPOSE: To evaluate the efficacy and toxicity of sequential, dose-intensified chemotherapy with paclitaxel/ifosfamide and carboplatin/etoposide administered plus peripheral blood-derived stem-cell (PBSC) support for patients with germ cell tumors (GCT) who have unfavorable prognostic features in response to conventional-dose salvage programs. Carboplatin was dose escalated by target area under the curve (AUC; in [milligrams per milliliter] x minutes) among patient cohorts, and pharmacokinetic studies were performed for comparison. PATIENTS AND METHODS: Thirty-seven previously treated patients who had cisplatin-resistant GCT and unfavorable prognostic features for response to conventional-dose salvage therapy were treated. Two cycles of paclitaxel 200 mg/m(2) plus ifosfamide 6 g/m(2) were given 2 weeks apart with leukapheresis, followed by three cycles of carboplatin plus etoposide given 14 to 21 days apart with reinfusion of PBSCs. The dose of etoposide was 1, 200 mg/m(2), and the carboplatin target AUC ranged among cohorts from 12 to 32 (mg/mL) x min. Pharmacokinetic studies of carboplatin were performed for comparison of target to measured AUC. RESULTS: Twenty-one patients (57%) achieved a complete response and an additional two patients (5%) achieved a partial response with normal tumor markers; therefore, 23 (62%) achieved a favorable response. Eight patients relapsed, and 15 (41%) of the favorable responses remained durable at a median follow-up of 30 months. Myelosuppression was the major toxicity; 58% of carboplatin/etoposide cycles were associated with hospitalization for nadir fever. The AUC of carboplatin measured in serum was lower than the target AUC; this may be related to underestimation of the glomerular filtration rate used in the dosing formula. CONCLUSION: Dose-intense therapy with sequential, accelerated chemotherapy of paclitaxel/ifosfamide and carboplatin/etoposide administered with PBSC support was relatively well tolerated. The durable complete response proportion was substantial in patients with unfavorable prognostic features for achieving durable complete response to conventional-dose salvage programs. Optimal dosing of carboplatin in the high-dose setting warrants further investigation.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Germinoma/tratamento farmacológico , Terapia de Salvação , Adolescente , Adulto , Área Sob a Curva , Carboplatina/administração & dosagem , Carboplatina/farmacocinética , Esquema de Medicação , Etoposídeo/administração & dosagem , Feminino , Transplante de Células-Tronco Hematopoéticas , Humanos , Ifosfamida/administração & dosagem , Leucaférese , Masculino , Pessoa de Meia-Idade , Paclitaxel/administração & dosagem , Estudos Prospectivos , Análise de Sobrevida
9.
J Anim Sci ; 93(9): 4387-400, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26440339

RESUMO

The objective of this study was to evaluate the effects of replacing monensin (MON) with a spray-dried multivalent polyclonal antibody preparation (PAP) against several ruminal microorganisms on feedlot performance, carcass characteristics, feeding behavior, blood gas profile, and the rumenitis incidence of Brangus and Nellore yearling bulls. The study was designed as a completely randomized design with a 2 × 2 factorial arrangement, replicated 6 times (4 bulls per pen and a total of 24 pens), in which bulls ( = 48) of each biotype were fed diets containing either MON fed at 300 mg/d or PAP fed at 3 g/d. No significant feed additive main effects were observed for ADG ( = 0.27), G:F ( = 0.28), HCW ( = 0.99), or dressing percentage ( = 0.80). However, bulls receiving PAP had greater DMI ( = 0.02) and larger ( = 0.02) final LM area as well as greater ( < 0.01) blood concentrations of bicarbonate and base excess in the extracellular fluid than bulls receiving MON. Brangus bulls had greater ( < 0.01) ADG and DMI expressed in kilograms, final BW, heavier HCW, and larger initial and final LM area than Nellore bulls. However, Nellore bulls had greater daily DMI fluctuation ( < 0.01), expressed as a percentage, and greater incidence of rumenitis ( = 0.05) than Brangus bulls. In addition, Brangus bulls had greater ( < 0.01) DMI per meal and also presented lower ( < 0.01) DM and NDF rumination rates when compared with Nellore bulls. Significant interactions ( < 0.05) between biotype and feed additive were observed for SFA, unsaturated fatty acids (UFA), MUFA, and PUFA concentrations in adipose tissues. When Nellore bulls were fed PAP, fat had greater ( < 0.05) SFA and PUFA contents but less ( < 0.01) UFA and MUFA than Nellore bulls receiving MON. For Brangus bulls, MON led to greater ( < 0.05) SFA and PUFA and less ( < 0.05) UFA and MUFA than Brangus bulls fed PAP. Feeding a spray-dried PAP led to similar feedlot performance compared with that when feeding MON. Spray-dried PAP might provide a new technology alternative to ionophores.


Assuntos
Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Anticorpos/farmacologia , Bovinos/fisiologia , Dieta/veterinária , Comportamento Alimentar/efeitos dos fármacos , Tecido Adiposo/efeitos dos fármacos , Animais , Composição Corporal/efeitos dos fármacos , Ionóforos/farmacologia , Masculino , Monensin/farmacologia
10.
J Invest Dermatol ; 105(1): 65-9, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7615978

RESUMO

Chronically sun-damaged human skin is characterized by dermal connective tissue damage that includes the massive accumulation of abnormal elastic fibers. The content of elastin, the major protein component of elastic fibers, is increased two- to sixfold in sun-damaged skin. The aim of this study was to determine the mechanism responsible for the increase in elastin levels after ultraviolet (UV) irradiation. Confluent cultures of normal dermal fibroblasts were irradiated with 4.5 mJ/cm2 of UVB; sham-treated cells served as the control group. The accumulation of tropoelastin was determined at 5 d after treatment by measuring the incorporation of 14C-proline into radiolabeled tropoelastin isolated from cell layers and media. UV irradiation increased radiolabeled tropoelastin accumulation approximately twofold without affecting DNA content, the total amount of radiolabeled protein, or tropoelastin secretion. Moreover, the steady-state levels of tropoelastin mRNA, as determined by slot blot hybridizations, were unaffected by UV treatment. However, the translation of tropoelastin mRNA was increased when total RNA from irradiated cells was used in cell-free translation experiments. These results suggest that altered translational efficiency may account for the increase in tropoelastin accumulation after UV irradiation. In support of this hypothesis, nucleotide sequences were derived from tropoelastin mRNA isolated from UV-irradiated and nonirradiated dermal fibroblasts. Almost a 12% substitution rate was observed in nucleotide sequences derived from the 3' untranslated region of tropoelastin mRNA from the UV-treated cells. In contrast, a coding domain of tropoelastin did not contain base-substitution mutations. These multiple base substitutions in a noncoding domain of tropoelastin mRNA may be responsible for the post-transcriptional increase in tropoelastin accumulation after UV irradiation.


Assuntos
Regulação da Expressão Gênica/efeitos da radiação , Pele/efeitos da radiação , Tropoelastina/biossíntese , Raios Ultravioleta , Sequência de Bases , Reparo do DNA , Fibroblastos/metabolismo , Fibroblastos/efeitos da radiação , Humanos , Dados de Sequência Molecular , Biossíntese de Proteínas/efeitos da radiação , RNA Mensageiro/análise , RNA Mensageiro/química , Pele/metabolismo , Tropoelastina/genética
11.
Cell Prolif ; 26(2): 161-70, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8097113

RESUMO

Anchorage independence and gene amplification have frequently been associated with a transformed or tumorigenic phenotype in cultured mammalian cells. However, it is unknown whether these two traits occur as related events during transformation, or are independent features of the transformed phenotype. To clarify this point, immortalized, untransformed CHEF18 Chinese hamster cells were propagated in culture until they became transformed and tumorigenic. The frequencies with which CHEF18 cells formed colonies either in soft agar, in medium containing N-phosphonacetyl-L-aspartate or in the two selective media simultaneously, were determined. The results indicate that anchorage independence and CAD gene amplification spontaneously arose during the propagation of the cells and that their concurrent emergence was not the consequence of independent events. However, the kinetics of their appearance suggests that anchorage independence is the early event whereas gene amplification might represent one of the numerous events which can be dynamically selected in anchorage-independent cells.


Assuntos
Ácido Aspártico/análogos & derivados , Adesão Celular , Transformação Celular Neoplásica , Amplificação de Genes , Ácido Fosfonoacéticos/análogos & derivados , Animais , Aspartato Carbamoiltransferase/genética , Ácido Aspártico/farmacologia , Carbamoil Fosfato Sintase (Glutamina-Hidrolizante)/genética , Linhagem Celular , Transformação Celular Neoplásica/genética , Cricetinae , Di-Hidro-Orotase/genética , Resistência a Medicamentos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Experimentais/etiologia , Ácido Fosfonoacéticos/farmacologia , Tioguanina/farmacologia
12.
Am J Med Genet ; 27(2): 245-8, 1987 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-3474898

RESUMO

The teratogenicity of vitamin A has been repeatedly reported in the literature and confirmed on the basis of several cases of adverse pregnancy outcome associated with maternal isotretinoin exposure. We report a case which shows a striking similarity with this syndrome, but the child was born to a mother who took a normal supplementation of vitamin A during pregnancy. The differential diagnosis is discussed.


Assuntos
Anormalidades Induzidas por Medicamentos/etiologia , Anormalidades Múltiplas/etiologia , Vitaminas/efeitos adversos , Anormalidades Induzidas por Medicamentos/diagnóstico , Anormalidades Múltiplas/induzido quimicamente , Anormalidades Múltiplas/diagnóstico , Adulto , Diagnóstico Diferencial , Feminino , Humanos , Recém-Nascido , Isotretinoína , Fenótipo , Gravidez , Tretinoína/efeitos adversos , Vitamina A/administração & dosagem , Vitamina A/efeitos adversos , Vitaminas/administração & dosagem
13.
Cancer Genet Cytogenet ; 85(1): 78-81, 1995 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8536244

RESUMO

Ten thousand four hundred ninety-two constitutional breakpoints available from the cytogenetic literature were analyzed for their coincidence with known fragile sites (FS) at 303-band resolution. In this analysis we have taken into account the stochastic connections of some features of chromosome bands with both the presence of FS and constitutional breakage. Our results suggest that there is no particular association between FS and constitutional chromosome rearrangements.


Assuntos
Aberrações Cromossômicas , Fragilidade Cromossômica , Bandeamento Cromossômico , Sítios Frágeis do Cromossomo , Rearranjo Gênico , Humanos
14.
Cancer Genet Cytogenet ; 46(2): 209-16, 1990 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2340492

RESUMO

The expression of fragile sites in three different Chinese hamster cell lines was studied. Results showed that folate-sensitive fragile sites were expressed in the pericentromeric regions of chromosomes 1, 3, 4, 6, and 7 and in band 1q22. A comparison of the breakpoints involved in formation of chromosome rearrangements in some established Chinese hamster cell lines was also made. Results showed that while the specific type of rearrangement was random, the breakpoints were not. Three of the chromosomal sites most frequently involved in breaks were regions in which fragile sites were expressed.


Assuntos
Fragilidade Cromossômica , Ácido Fólico/farmacologia , Animais , Linhagem Celular , Bandeamento Cromossômico , Sítios Frágeis do Cromossomo , Cricetinae , Cricetulus , Cariotipagem , Metotrexato/toxicidade
15.
Anticancer Res ; 11(3): 1071-6, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1653552

RESUMO

This study investigates the cytotoxic and genotoxic effects of various carboxy AQ, 1,4-dihydroxy 6-carboxy AQ, 1,8-dihydroxy 3-carboxy AQ, 1,4-dihydroxy AQ, 1,5-dihydroxy AQ, 1,8-dihydroxy AQ and 2,6-dihydroxy AQ in V79 Chinese hamster cells. The V79 cells were used since, as they contain flavoproteins but not cytochrome P-450, they can bioactive xenobiotics only through the reductive pathway excluding the oxidative one. In addition, the abilities of AQs to stimulate O2-production using both purified flavoproteins (NADH-dehydrogenase, NADPH-cytochrome P-450 reductase) and V79 subcellular fractions (homogenate and microsomes) were assayed. The NADH and NADPH consumption stimulated by AQs in V79 microsomes was also determined. The results showed that the carboxylic-containing drugs and the 1,4-dihydroxy AQ were weak sister chromatid exchange inducers and the most toxic among the six anthraquinones examined. Dicumarol, a potent inhibitor of DT-diaphorase, reduced, rather than potentiated, both the cytotoxicity and genotoxicity caused by these AQs. Thus, the higher superoxide formation rates stimulated by the carboxylic-containing AQs compared to those of the other quinones with all the in vitro systems used, suggested, except for the 1,4-dihydroxy AQ, a possible relationship between cytotoxicity and O2-production. For the 1,4-dihydroxy AQ toxicity, a specific bioactivation route was hypothesized.


Assuntos
Antraquinonas/toxicidade , Superóxidos/metabolismo , Animais , Antraquinonas/metabolismo , Linhagem Celular , Cricetinae , Microssomos/metabolismo , NAD/metabolismo , NADP/metabolismo , NADPH-Ferri-Hemoproteína Redutase/análise , Quinona Redutases/fisiologia , Troca de Cromátide Irmã/efeitos dos fármacos
16.
Chem Biol Interact ; 42(1): 45-51, 1982 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-6891292

RESUMO

The biological activity of potassium dichromate (K2Cr2O7) was assayed in V79/AP4 Chinese hamster cells by measuring two mutational end points, thioguanine (TG) resistance and ouabain (OUA) resistance, and two non-mutational end points, cytotoxicity and sister chromatid exchanges (SCE). By exposing the cells for 1 h to the chemical, all biological end points examined were affected by the treatment in a dose-dependent manner. Moreover the combined use of the two selective systems indicated that chromium induces base-pair substitutions in mammalian cells in culture.


Assuntos
Cromatos/farmacologia , Troca Genética/efeitos dos fármacos , Ouabaína/metabolismo , Dicromato de Potássio/farmacologia , Troca de Cromátide Irmã/efeitos dos fármacos , Tioguanina/metabolismo , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cricetinae , Cricetulus
17.
Mutat Res ; 266(2): 273-9, 1992 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1373836

RESUMO

In cultured mammalian cells, sister chromatid exchanges are easily induced by agents that perturb the scheduled timing of DNA replication. In this work a blockage of DNA synthesis induced by 1-beta-D-arabinofuranosylcytosine was applied to non-tumorigenic and tumorigenic CHEF18 Chinese hamster cells, and their responsiveness was compared. The data show that both the induction of sister chromatid exchanges and the reduction of the colony-forming ability were less extensive in non-tumorigenic than in tumorigenic CHEF18 cells. The results suggest that a tight control of the scheduled timing of DNA replication is present in non-tumorigenic CHEF18 cells and perhaps this feature avoids the generation of those chromosomal structures that are responsible for the abnormal induction of sister chromatid exchanges and for the elevated cytotoxicity seen in tumorigenic cells.


Assuntos
Transformação Celular Neoplásica , Citarabina/toxicidade , Troca de Cromátide Irmã/efeitos dos fármacos , Animais , Ciclo Celular , Células Cultivadas , Cricetinae , Cricetulus , DNA/biossíntese
18.
Mutat Res ; 291(3): 163-9, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7685057

RESUMO

Electroporation is a recent technique used to introduce exogenous DNA into eukaryotic cells. It is important to establish that the gene of interest is transferred into a functional, non-mutated recipient cell. V79/AP4 Chinese hamster cells were exposed to high-voltage pulsed electric fields and some biological and genetic effects were measured. The results showed that cytotoxicity was related in a dose-dependent manner to the number of applied pulses. Thioguanine-resistant colony-forming cells as well as chromosomal aberrations were also induced whereas ouabain resistants and sister-chromatid exchanges were not or slightly induced. Spontaneous and electroporation-induced clones that were phenotypically TGR/HATS were used to investigate the hprt locus. Molecular screening of the locus showed that the number of deleted exons was significantly higher in induced than in spontaneous TG-resistant clones, suggesting that the genetic damages induced by electroporation concern the loss of regions well over the size of the hprt locus.


Assuntos
Dano ao DNA , Eletricidade , Animais , Sobrevivência Celular , Células Cultivadas , Aberrações Cromossômicas , Cricetinae , Cricetulus , Hipoxantina Fosforribosiltransferase/genética , Mutação , Reação em Cadeia da Polimerase , Troca de Cromátide Irmã , Tioguanina/farmacologia
19.
Mutat Res ; 177(2): 255-60, 1987 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3561424

RESUMO

To study the origin of induced aneuploid cells, the BrUdR-labelling technique was applied to V79/AP4 Chinese hamster cells treated with colcemid or benomyl. In this way we were able to recognize the cells which had undergone one cellular division after the treatment since their chromosomes exhibited sister-chromatid differentiation. The results showed that the induced aneuploid cells can have either a few or numerous additional chromosomes depending on the concentrations of the drug. Moreover, it could be established that aneuploid cells with numerous additional chromosomes were obtained mainly when polyploid cells were also present in the treated population. This strongly suggests that the excess of additional chromosomes found in the aneuploid cells induced by the highest concentrations may be derived by disturbances of the whole mitotic apparatus rather than by a multiplicity of errors affecting individual chromosomes.


Assuntos
Aneuploidia , Benomilo/farmacologia , Carbamatos/farmacologia , Demecolcina/farmacologia , Animais , Bromodesoxiuridina , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Cricetinae , Mitose/efeitos dos fármacos , Troca de Cromátide Irmã/efeitos dos fármacos
20.
Mutat Res ; 202(1): 185-92, 1988 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-3185590

RESUMO

The chromosomal location of the autosomal locus aprt has been investigated in the permanent Chinese hamster cell line V79-AP4 by standard somatic cell genetics methodologies. Aprt is functionally dizygous in V79-AP4 and the 2 alleles map on 2 chromosome 3 homologs, in agreement with the chromosome assignment of the gene in Chinese hamster primary cells. Chromosome G-banding and a Southern blot analysis of V79-AP4 DNA, using as a probe the cloned Chinese hamster aprt gene, have not revealed any structural alteration at either of the 2 aprt alleles. One of the chromosomes 3 has, however, a terminal deletion in its long arm and is therefore morphologically marked. These findings could make V79-AP4 an interesting cell system for the study of mutational mechanisms at the aprt locus in Chinese hamster.


Assuntos
Adenina Fosforribosiltransferase/genética , Cricetinae/genética , Cricetulus/genética , Testes de Mutagenicidade/métodos , Pentosiltransferases/genética , 2-Aminopurina/análogos & derivados , 2-Aminopurina/farmacologia , Animais , Southern Blotting , Linhagem Celular , Bandeamento Cromossômico , Mapeamento Cromossômico , Sondas de DNA , Isoenzimas , L-Lactato Desidrogenase/genética
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