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1.
Eur Arch Paediatr Dent ; 23(4): 513-525, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35429295

RESUMO

PURPOSE: We aimed to systematically evaluate whether SHS exposure is associated with poor periodontal status in individuals up to 15 years. METHODS: Seven databases were searched by two independent reviewers according to pre-specified eligibility criteria up to November 2021. The methodological quality of included studies was appraised using The Newcastle-Ottawa Scale and GRADE was used for assessing the certainty of evidence. Random-effects pairwise meta-analyses compared the periodontal status of those exposed and unexposed to SHS through standardized mean differences (SMDs) and associated confidence intervals (95% CI). RESULTS: Eight cross-sectional studies were eligible for inclusion and two present high methodological quality. All studies contributed to the meta-analysis for gingival index scores (GI) and four for probing pocket depth (PPD). Those exposed exhibited significantly higher levels of GI compared to unexposed (SMD = 1.03, 95% CI 0.17-1.89), but no difference was observed for PPD (SMD = 0.34, 95% CI - 0.14-0.82), with overall very low certainty on evidence. CONCLUSION: Therefore, very low certainty evidence supports that children and adolescents exposed to SHS possibly present poorer periodontal status due to higher levels of GI.


Assuntos
Poluição por Fumaça de Tabaco , Adolescente , Criança , Estudos Transversais , Humanos , Índice Periodontal , Poluição por Fumaça de Tabaco/efeitos adversos
3.
Rev. bras. ciênc. avic ; 23(4): eRBCA, 2021. ilus, tab
Artigo em Inglês | VETINDEX | ID: biblio-1490889

RESUMO

Fragments with vibrant colors and attractive textures in poultry house litter may be consumed considering that the confinement environment does not offer many opportunities for the development of the birds’s natural behavior. Control and quality programs aiming to reduce and to eliminate the consumption of materials from the construction of sheds have been implanted. However, it is necessary to develop studies for a better understanding of the bird’s ingestive behavior and the consequences for their health, welfare and productivity. The goal of this study was to evaluate the ingestive behavior of broilers exposed to metal, wood, glass and plastic fragments at different concentrations and sizes added to the poultry house litter and the integrity of the gastrointestinal tract of broilers. A total of 360 birds were distributed in a completely randomized design over a 2x3 factorial scheme (2 fragment sizes: 2 to 7 mm and 5 to 8 mm and 3 concentrations: 0.1, 0.5 and 1%), totaling 6 treatments and 5 replicates. The fragments used were glass, wood, metal and plastic, in respective concentrations and sizes, distributed in the poultry house litter. The supply of fragments or the accidental occurrence of similar fragments to which were analyzed in this study concerning the poultry house litter, with different sizes, colors and textures does not compromise the integrity of the mucosa of the gastrointestinal tract and the welfare of the birds.


Assuntos
Animais , Bem-Estar do Animal , Galinhas/anatomia & histologia , Galinhas/fisiologia , Trato Gastrointestinal
4.
R. bras. Ci. avíc. ; 23(4): eRBCA-2020-1414, 2021. ilus, tab
Artigo em Inglês | VETINDEX | ID: vti-32255

RESUMO

Fragments with vibrant colors and attractive textures in poultry house litter may be consumed considering that the confinement environment does not offer many opportunities for the development of the birdss natural behavior. Control and quality programs aiming to reduce and to eliminate the consumption of materials from the construction of sheds have been implanted. However, it is necessary to develop studies for a better understanding of the birds ingestive behavior and the consequences for their health, welfare and productivity. The goal of this study was to evaluate the ingestive behavior of broilers exposed to metal, wood, glass and plastic fragments at different concentrations and sizes added to the poultry house litter and the integrity of the gastrointestinal tract of broilers. A total of 360 birds were distributed in a completely randomized design over a 2x3 factorial scheme (2 fragment sizes: 2 to 7 mm and 5 to 8 mm and 3 concentrations: 0.1, 0.5 and 1%), totaling 6 treatments and 5 replicates. The fragments used were glass, wood, metal and plastic, in respective concentrations and sizes, distributed in the poultry house litter. The supply of fragments or the accidental occurrence of similar fragments to which were analyzed in this study concerning the poultry house litter, with different sizes, colors and textures does not compromise the integrity of the mucosa of the gastrointestinal tract and the welfare of the birds.(AU)


Assuntos
Animais , Galinhas/anatomia & histologia , Galinhas/fisiologia , Trato Gastrointestinal , Bem-Estar do Animal
5.
Arq. bras. med. vet. zootec. (Online) ; 70(5): 1641-1644, set.-out. 2018. tab
Artigo em Português | VETINDEX | ID: vti-20625

RESUMO

Pregnancy can cause several physiologic changes in mares, including modifications in cardiac output and heart positioning. Therefore, these changes could influence electrocardiographic parameters in various stages of pregnancy. This study aimed to evaluate the electrocardiogram of Crioulo mares in different pregnancy stages. Nine non pregnant mares (G0), 11 mares at three months (G3), 11 mares at six months (G6) and 11 mares at 10 months of pregnancy (G10) were submitted to electrocardiographic evaluation. There was higher (P= 0,002) heart rate of G10 (60.45±12.16bpm) when compared to other groups (G0=45.67±10.75bpm; G3=44.91±7.91bpm; G6=46.91±9.12bpm), probably because of an increase in cardiac output to uterine perfusion at the end of pregnancy. Normal sinus rhythm was predominant in most of mares of groups G0, G3 and G6, and sinus tachycardia in most of G10 mares. In conclusion, changes in hemodynamics and in cardiac position can influence on the electrocardiogram of pregnant Crioulo mares, but do not cause relevant rhythm or conduction disturbs.(AU)


Assuntos
Animais , Feminino , Gravidez , Eletrocardiografia/classificação , Idade Gestacional , Cavalos/classificação
6.
Arq. bras. med. vet. zootec. (Online) ; 70(5): 1641-1644, set.-out. 2018. tab
Artigo em Português | LILACS, VETINDEX | ID: biblio-947781

RESUMO

Pregnancy can cause several physiologic changes in mares, including modifications in cardiac output and heart positioning. Therefore, these changes could influence electrocardiographic parameters in various stages of pregnancy. This study aimed to evaluate the electrocardiogram of Crioulo mares in different pregnancy stages. Nine non pregnant mares (G0), 11 mares at three months (G3), 11 mares at six months (G6) and 11 mares at 10 months of pregnancy (G10) were submitted to electrocardiographic evaluation. There was higher (P= 0,002) heart rate of G10 (60.45±12.16bpm) when compared to other groups (G0=45.67±10.75bpm; G3=44.91±7.91bpm; G6=46.91±9.12bpm), probably because of an increase in cardiac output to uterine perfusion at the end of pregnancy. Normal sinus rhythm was predominant in most of mares of groups G0, G3 and G6, and sinus tachycardia in most of G10 mares. In conclusion, changes in hemodynamics and in cardiac position can influence on the electrocardiogram of pregnant Crioulo mares, but do not cause relevant rhythm or conduction disturbs.(AU)


Assuntos
Animais , Feminino , Gravidez , Eletrocardiografia/classificação , Idade Gestacional , Cavalos/classificação
7.
J Mater Sci Mater Med ; 25(1): 229-37, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24072391

RESUMO

It is of current interest the identification of appropriate matrices for growing mesenchymal stem cells (MSC). These cells are able not only to regenerate themselves but also to differentiate into other type of functional cells, and so they have been extensively used in tissue engineering. In this work, we have evaluated the use of electric impedance spectroscopy (EIS) to follow the adhesion of MSC from Wharton's jelly of the human umbilical cord (hWJMSC) on sugarcane biopolymers (SCB). Impedance spectra of the systems were obtained in the frequency range of 10(2)-10(5) Hz. An EIS investigation showed that when deposited on a metallic electrode SCB films prevent the passage of electrons between the solution and the metallic interface. The impedance spectra of hWJMSCs adhered on SCB revealed that there is a significant increase in the magnitude of the impedance when compared to that of pure SCB. The corresponding resistance (real part of the impedance) was even higher for the SCB-hWJMSC system than for SCB without cells on their surface, in an indication of an increased blockage to the electron transfers. The resistance charge transfer is extracted by curve-fitting the impedance spectra to an equivalent circuit model. Also, a shift of the phase angle to higher frequencies was obtained for SCB-hWJMSC system as a result from hWJMSC adhesion. Our study demonstrates that EIS is an appropriate method to evaluate the adhesion of MSC. SCB can be considered as a promising biomaterial for tissue engineering.


Assuntos
Materiais Biocompatíveis/química , Biopolímeros/química , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/fisiologia , Saccharum/química , Cordão Umbilical/citologia , Adesão Celular , Células Cultivadas , Impedância Elétrica , Feminino , Humanos , Teste de Materiais , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Gravidez , Engenharia Tecidual , Geleia de Wharton/citologia
8.
Neotrop Entomol ; 43(1): 1-8, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27193398

RESUMO

Mealybugs have strong associations with their host plants due to their limitations for dispersal. Thus, environmental conditions and host quality may impact the biological traits of mealybugs. To the best of our knowledge, we are the first to report on the biology of a Brazilian population of the striped mealybug Ferrisia virgata Cockerell (Hemiptera: Pseudococcidae), which has recently been reported to infest cotton in Brazil. We evaluated the development and reproductive performance of F. virgata reared under different temperatures (25, 27, and 28°C) and mating status. The type of reproduction was also studied with insects reared on a factitious host and on cotton plants. Shorter development was obtained at 28°C as follows: nymphs generating males and females exhibited three and four instars with a mean duration of 19.1 and 20.5 days, respectively. The nymphal viability ranged from 77 to 96%, and was highest at 25°C. Females reared at 28°C initiated reproduction earlier (16.4 days), but the reproductive period was similar in all temperatures (∼16.2 days). Females produced more nymphs at 27 and 28°C (440 and 292 neonates) than at 25°C (277 neonates), although they lived longer at 25°C (63 days). Ferrisia virgata females exhibited only sexual reproduction. Thus, only mated females produced offspring, whereas unmated females died without reproducing. Therefore, the studied population of F. virgata exhibited only sexual reproduction with high survival and offspring production when fed cotton. Furthermore, pumpkin is a feasible host for mass rearing this mealybug species in the laboratory, an opening avenue for future studies.


Assuntos
Hemípteros , Reprodução , Temperatura , Animais , Brasil , Feminino , Masculino , Ninfa
9.
Eur Arch Paediatr Dent ; 13(2): 91-3, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22449809

RESUMO

AIM: To evaluate the reproducibility of 7 validation methods used for caries diagnosis in primary teeth. METHODS: Seventy-two occlusal sites were selected on 40 primary molars. The sites were evaluated independently by 3 experienced examiners using validation methods that involved direct assessment, i.e. by using a (1) magnifying glass (8×) and (2) stereomicroscope (35×), or indirect assessment i.e. by using (3) photographs, (4) slide projections of photographs, (5) stereomicroscope (35×) photographs, (6) stereomicroscope (35×) slide projections, and (7) projections of polarised light microscope slides. Cohen's kappa coefficients were calculated and subjected to the Kruskal-Wallis test at a significance level of 5%. RESULTS: The mean inter-examiner kappa values for the validation methods were 0.31-0.51. There were statistically significant differences (p<0.05) between methods 1 and 3, 1 and 4, 2 and 4, 4 and 5, 4 and 6, and 4 and 7. Moderate agreement was observed for all methods except methods 1 and 4, for which the agreement was fair. CONCLUSIONS: The inter-examiner agreement for all validation methods for caries diagnosis was moderate, except for the method based on indirect assessment by slide projection, which showed low agreement.


Assuntos
Cárie Dentária/diagnóstico , Dente Molar/patologia , Dente Decíduo/patologia , Humanos , Lentes , Microscopia , Microscopia de Polarização , Variações Dependentes do Observador , Fotografia Dentária , Exame Físico , Descoloração de Dente/diagnóstico
10.
Work ; 41 Suppl 1: 4124-9, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22317354

RESUMO

This article presents a description of a study experience developed in the Discipline of Supervised Internship of the Industrial Design Course of the Federal University of Paraíba. The study is based on focused on ergonomics analysis and accessibility as an object of study, access into and out of buildings of classrooms and laboratories of the same institution. Among the buildings selected, which encompass where the course is established, is a contemporary building and a renovated building of historical and artistic values for current use. The study is characterized by a description of the objects of study, analysis of the reference literature and recommendations for adjustments in the event of any inconsistency with the accessibility standards. The experience of this supervised training provided an opportunity to perform design activities to a group of students in applied ergonomics, as well as enabling contact with professional practice, adding the contact with the appropriate guidelines governing intervention in historic heritage buildings.


Assuntos
Acessibilidade Arquitetônica , Ergonomia , Instituições Acadêmicas , Acessibilidade Arquitetônica/legislação & jurisprudência , Currículo , Humanos
11.
Braz J Biol ; 71(2): 431-6, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21755160

RESUMO

To use Palmistichus elaeisis Delvare and LaSalle, 1993 (Hymenoptera: Eulophidae) in a biological control programme of Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae), it is necessary to study thermal requirements, because temperature can affect the metabolism and bioecological aspects. The objective was to determine the thermal requirements and estimate the number of generations of P. elaeisis in different Eucalyptus plantations regions. After 24 hours in contact with the parasitoid, the pupae was placed in 16, 19, 22, 25, 28 and 31 °C, 70 ± 10% of relative humidity and 14 hours of photophase. The duration of the life cycle of P. elaeisis was reduced with the increase in the temperature. At 31 °C the parasitoid could not finish the cycle in T. arnobia pupae. The emergence of P. elaeisis was not affected by the temperature, except at 31 °C. The number of individuals was between six and 1238 per pupae, being higher at 16 °C. The thermal threshold of development (Tb) and the thermal constant (K) of this parasitoid were 3.92 °C and 478.85 degree-days (GD), respectively, allowing for the completion of 14.98 generations per year in Linhares, Espírito Santo State, 13.87 in Pompéu and 11.75 in Viçosa, Minas Gerais State and 14.10 in Dourados, Mato Grosso do Sul State.


Assuntos
Eucalyptus/parasitologia , Himenópteros/crescimento & desenvolvimento , Lepidópteros/parasitologia , Temperatura , Animais , Feminino , Himenópteros/fisiologia , Controle Biológico de Vetores/métodos , Pupa/parasitologia
12.
Braz. J. Biol. ; 71(2): 431-436, May 2011. graf
Artigo em Inglês | VETINDEX | ID: vti-11064

RESUMO

To use Palmistichus elaeisis Delvare and LaSalle, 1993 (Hymenoptera: Eulophidae) in a biological control programme of Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae), it is necessary to study thermal requirements, because temperature can affect the metabolism and bioecological aspects. The objective was to determine the thermal requirements and estimate the number of generations of P. elaeisis in different Eucalyptus plantations regions. After 24 hours in contact with the parasitoid, the pupae was placed in 16, 19, 22, 25, 28 and 31 °C, 70 ± 10 percent of relative humidity and 14 hours of photophase. The duration of the life cycle of P. elaeisis was reduced with the increase in the temperature. At 31 °C the parasitoid could not finish the cycle in T. arnobia pupae. The emergence of P. elaeisis was not affected by the temperature, except at 31 °C. The number of individuals was between six and 1238 per pupae, being higher at 16 °C. The thermal threshold of development (Tb) and the thermal constant (K) of this parasitoid were 3.92 °C and 478.85 degree-days (GD), respectively, allowing for the completion of 14.98 generations per year in Linhares, Espírito Santo State, 13.87 in Pompéu and 11.75 in Viçosa, Minas Gerais State and 14.10 in Dourados, Mato Grosso do Sul State.(AU)


Para o uso de Palmistichus elaeisis Delvare e LaSalle, 1993 (Hymenoptera: Eulophidae) no controle biológico de Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae) em eucalipto, é necessário estudar suas exigências térmicas, pois a temperatura pode afetar o metabolismo e aspectos bioecológicos dos insetos. Objetivou-se assim, determinar as exigências térmicas e o número de gerações de P. elaeisis em diferentes regiões com florestas de Eucalyptus. Permitiu-se o parasitismo por 24 horas e, após esse período, as pupas foram transferidas para câmaras climatizadas a 16, 19, 22, 25, 28 e 31 °C, 70 ± 10 por cento de umidade relativa e fotofase de 14 horas. Verificou-se que o aumento da temperatura reduziu a duração média do ciclo de vida de P. elaeisis, sendo que a 31 °C o parasitoide não concluiu seu ciclo de vida em pupas de T. arnobia. A progênie do parasitoide por pupa variou de 6 a 1238 indivíduos e foi maior a 16 °C. A temperatura base (Tb) e constante térmica (K) desse parasitoide foram de 3,92 °C e 478,85 graus-dia, respectivamente. O número estimado de gerações anuais de P. elaeisis, em pupas de T. arnobia, para os municípios de Linhares, ES, Pompéu e Viçosa, MG e Dourados, MS foi de 14,98; 13,87; 11,75; e 14,10, respectivamente.(AU)


Assuntos
Animais , Feminino , Eucalyptus/parasitologia , Himenópteros/crescimento & desenvolvimento , Lepidópteros/parasitologia , Temperatura , /fisiologia , Controle Biológico de Vetores/métodos , Pupa/parasitologia
13.
Braz J Biol ; 70(3 Suppl): 831-40, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21085788

RESUMO

The invasive golden mussel, Limnoperna fortunei (Dunker, 1857), was introduced into the La Plata River estuary and quickly expanded upstream to the North, into the Paraguay and Paraná rivers. An ecological niche modeling approach, based on limnological variables, was used to predict the expansion of the golden mussel in the Paraguay River and its tributaries. We used three approaches to predict the geographic distribution: 1) the spatial distribution of calcium concentration and the saturation index for calcium carbonate (calcite); 2) the Genetic Algorithm for Rule-Set Production (GARP) model; and the 3) Maximum Entropy Method (Maxent) model. Other limnological variables such as temperature, dissolved oxygen, pH, and Total Suspended Solids (TSS) were used in the latter two cases. Important tributaries of the Paraguay River such as the Cuiabá and Miranda/Aquidauana rivers exhibit high risk of invasion, while lower risk was observed in the chemically dilute waters of the middle basin where shell calcification may be limited by low calcium concentrations and carbonate mineral undersaturation.


Assuntos
Carbonato de Cálcio/análise , Monitoramento Ambiental/métodos , Espécies Introduzidas , Mytilidae/fisiologia , Rios/química , Algoritmos , Animais , Brasil , Mytilidae/classificação , Dinâmica Populacional
14.
Lett Appl Microbiol ; 46(3): 371-6, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18266644

RESUMO

AIMS: The aim of this work was to analyse the antimicrobial properties of a purified lectin from Eugenia uniflora L. seeds. METHODS AND RESULTS: The E. uniflora lectin (EuniSL) was isolated from the seed extract and purified by ion-exchange chromatography in DEAE-Sephadex with a purification factor of 11.68. The purified lectin showed a single band on denaturing electrophoresis, with a molecular mass of 67 kDa. EuniSL agglutinated rabbit and human erythrocytes with a higher specificity for rabbit erythrocytes. The haemagglutination was not inhibited by the tested carbohydrates but glycoproteins exerted a strong inhibitory action. The lectin proved to be thermo resistant with the highest stability at pH 6.5 and divalent ions did not affect its activity. EuniSL demonstrated a remarkable nonselective antibacterial activity. EuniSL strongly inhibited the growth of Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella sp. with a minimum inhibitory concentration (MIC) of 1.5 microg ml(-1), and moderately inhibited the growth of Bacillus subtilis, Streptococcus sp. and Escherichia coli with a MIC of 16.5 microg ml(-1). CONCLUSIONS: EuniSL was found to be effective against bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: The strong antibacterial activity of the studied lectin indicates a high potential for clinical microbiology and therapeutic applications.


Assuntos
Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Lectinas , Sementes/química , Syzygium/química , Hemaglutinação , Testes de Inibição da Hemaglutinação , Humanos , Lectinas/química , Lectinas/isolamento & purificação , Lectinas/metabolismo , Lectinas/farmacologia , Testes de Sensibilidade Microbiana
15.
Arq Neuropsiquiatr ; 54(2): 202-6, 1996 Jun.
Artigo em Português | MEDLINE | ID: mdl-8984975

RESUMO

Electroencephalographic changes have been detected in children with premature pubarche. These findings might be the result from past or current central nervous system dysfunction, or from increased sex steroids. In order to test the last assertion we have performed electroencephalographic studies in 10 patients (7F, 3M) with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency, of whom 4 classic and 6 nonclassic forms of the syndrome. Traditional neurologic examination was performed in 7 patients, the result being considered normal in everyone, while evolutional neurologic examination detected hyperactive disturbance and attention deficit in two patients. In another patient, the clinical findings were compatible with delay of neuropsychomotor development. Quantitative electroencephalography with brain mapping in patients over three years-old (n = 9), and conventional EEG in the remaining patient, were considered abnormal for age in 8 patients (80%), the record being characterized as slow in 7 patients. The high rate of electroencephalographic changes in this sample, as well as in premature pubarche, suggests that these findings might result from high inappropriate for age androgenic levels, and warns about the importance of neurologic examination and follow-up in children with CAH.


Assuntos
Hiperplasia Suprarrenal Congênita/fisiopatologia , Adolescente , Mapeamento Encefálico , Criança , Pré-Escolar , Eletroencefalografia , Feminino , Humanos , Lactente , Masculino , Exame Neurológico , Estudos Prospectivos , Puberdade Precoce/fisiopatologia
16.
Mutat Res ; 265(2): 237-44, 1992 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1370722

RESUMO

The influence of beta-carotene on the clastogenicity of the indirect-acting mutagen cyclophosphamide (CPA) was investigated in mice, in vivo, for the induction of chromosome aberrations in bone marrow cells (BM). beta-Carotene (0.5, 1.0, 2.0, 5.0, 10, 25, 50, 100 and 200 mg/kg) was administered by gavage for 5 consecutive days. 4 h after the last treatment with beta-carotene, the mice were injected intraperitoneally with CPA, and the BM cells were fixed after 16, 24 and 32 h for the evaluation of the frequency of chromosome aberrations. The results showed that beta-carotene was effective in reducing chromosomal damage induced by CPA with the increase of its concentration up to a level after which this effect was not observed. This anticlastogenicity was better detected when the cells were fixed at 32 h, although a tendency in reducing the CPA clastogenicity was already observed at 16 and 24 h. Our results suggest that beta-carotene provides significant protection against the genotoxicity of CPA, although no dose-effect relationship on the frequencies of cells with chromosomal aberrations was observed.


Assuntos
Antimutagênicos/farmacologia , Carotenoides/farmacologia , Ciclofosfamida/antagonistas & inibidores , Animais , Aberrações Cromossômicas , Ciclofosfamida/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos BALB C , beta Caroteno
17.
Environ Mol Mutagen ; 20(3): 206-10, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1396611

RESUMO

The inhibitory effects of beta-carotene on cyclophosphamide (CPA)-induced chromosomal aberrations in mouse bone marrow cells were investigated. Male Balb C mice, 8-10 weeks old, were treated with beta-carotene (0.5, 1.0, 2.0, 5.0, 10, 25, 50, 100, and 200 mg/kg) or with corn oil (0.05 ml/10 g b.w.) by gavage for 5 consecutive days. Four hours after the last treatment with or without beta-carotene, the animals were intraperitoneally injected with CPA and killed 24 hr later for cytological preparations and analysis. The results obtained show that beta-carotene provides significant protection against the clastogenicity of CPA. The maximum reduction in the frequency of aberrant metaphases (26.9%) and in total number of chromosomal aberrations were observed when beta-carotene was used at 50 mg/kg. Nevertheless, no direct dose-response relationship was detected, suggesting that beta-carotene might act through different mechanisms at different doses. The results obtained in animals studies have served as part of the basis for the human intervention studies now underway to determine if beta-carotene does indeed function as a chemopreventive agent in human nutrition.


Assuntos
Antimutagênicos/farmacologia , Medula Óssea/efeitos dos fármacos , Carotenoides/farmacologia , Aberrações Cromossômicas , Ciclofosfamida/farmacologia , Mutagênicos/farmacologia , Animais , Células da Medula Óssea , Masculino , Camundongos , Camundongos Endogâmicos BALB C , beta Caroteno
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