Evaluation of the potential of Pistia stratiotes L. (water lettuce) for bioindication and phytoremediation of aquatic environments contaminated with arsenic / Avaliação do potencial de Pistia stratiotes L. (alface d'água) para a bioindicação e fitorremediação de ambientes aquáticos contaminados com arsênio

Specimens of Pistia stratiotes were subjected to five concentrations of arsenic (As) for seven days. Growth, As absorption, malondialdehyde (MDA) content, photosynthetic pigments, enzymatic activities, amino acids content and anatomical changes were assessed. Plant arsenic accumulation increased with increasing metalloid in the solution, while growth rate and photosynthetic pigment content decreased. The MDA content increased, indicating oxidative stress. Enzymatic activity and amino acids content increased at the lower doses of As, subsequently declining in the higher concentrations. Chlorosis and necrosis were observed in the leaves. Leaves showed starch accumulation and increased thickness of the mesophyll. In the root system, there was a loss and darkening of roots. Cell layers formed at the insertion points on the root stems may have been responsible for the loss of roots. These results indicate that water lettuce shows potential for bioindication and phytoremediation of As-contaminated aquatic environments.(AU)

Espécimes de Pistia stratiotes foram submetidos a cinco concentrações de arsênio (As), durante sete dias. Crescimento, absorção de As, concentração de malondialdeído (MDA), pigmentos fotossintéticos, atividades enzimáticas, concentração de aminoácidos e alterações anatômicas foram avaliadas. O acúmulo de As pelas plantas aumentou com o incremento do metaloide na solução, enquanto que a taxa de crescimento e o teor de pigmentos fotossintéticos diminuiu. O conteúdo MDA aumentou, indicando estresse oxidativo. A atividade de enzimas antioxidantes e os teores de aminoácidos aumentaram nas doses mais baixas de As, declinando nas concentrações mais elevadas. Nas folhas foram observados clorose e necrose. As folhas apresentaram acumulação de amido e aumento da espessura do mesofilo. No sistema radicular houve perda e escurecimento das raízes. Camadas de células formadas nos pontos de inserção da raiz podem ter sido responsáveis pela queda das raízes. Estes resultados indicam que a alface da água apresenta potencial para bioindicação e fitorremediação de ambientes aquáticos contaminados com As.(AU)

Influences of nutrition and metabo lism on fertility of dairy cows

During early postpartum, high-producing dairy cows undergo a period of extensive tissue catabolism because of negative nutrien t balance. Homeorrhetic controls assure that nutrients are partitioned to favor lactation at the same time that homeostasis secures survival. However, unrestrained metabolic disturbances often lead to diseases which, in turn, dramatically decrease both productive and reproductive performance. Negative nutrient balance ha s been associated with compromised immune and reproductive functions in dairy cows. Low circulating concentrations of glucose and insulin associated with elevated concentrations of non-esterified fatty acids and ketone bodies postpartum have disruptive and detrimental effects on the oocyte, granulosa and immune cells. Negative nutrient balance is associated with changes in the pattern of ovarian follicle growth which can indirectly affect oocyte quality. Some of this disruption seems to be the result of endocrine and biochemical changes that alter the micro- environment of the growing and maturing oocyte. In addition, cows under negative nutrient balance have extended periods of anovulation. Postpartum anestrus, as well as infertility, is magnified by losses of body condition during the early postpartum period. The underlying mechanism for resumption of ovulatory cycles seems to be associated with metabolic signals and regulatory hormones primarily insulin and insulin- like growth factor (IGF)-1, which link nutritional status with gonadotropin secretion, recoupling of the growth hormone-IGF system, and follicle maturation and ovulation. Feeding diets th at promote increases in plasma glucose and insulin may improve the metabolic and endocrine status of cows in early lactation. Furthermore, fertility in postpartum cows is also determined by uterine health. Reductions in circulating concentrations of Ca and antioxidant vitamins around parturition are also linked with impaired immune competence and result in greater risk of uterine diseases that impair reproduction. Specific nutrients and dietary ingredients have been implicated to affect reproduction in cattle. Excess intake of dietary protein has been suggested as detrimental to fertility, although feeding excess of dietary protein can no longer be justified. Addition of moderate amounts of supplemental fat to the diet improves caloric intake, modulates prostaglandin F2  secretion by the uterus, affects ovarian dynamics, enhances luteal function and embryo quality, and has moderate positive effects on fertility. More specifically, some fatty acids might impact fertilization rate and embryo quality in dairy cows. On the contrary, some dietary ingredients, such as gossypol, when ingested in large quantities decrease fertility of dairy cows because of its negative effects on embryo quality and pregnancy maintenance.

Influences of nutrition and metabo lism on fertility of dairy cows

During early postpartum, high-producing dairy cows undergo a period of extensive tissue catabolism because of negative nutrien t balance. Homeorrhetic controls assure that nutrients are partitioned to favor lactation at the same time that homeostasis secures survival. However, unrestrained metabolic disturbances often lead to diseases which, in turn, dramatically decrease both productive and reproductive performance. Negative nutrient balance ha s been associated with compromised immune and reproductive functions in dairy cows. Low circulating concentrations of glucose and insulin associated with elevated concentrations of non-esterified fatty acids and ketone bodies postpartum have disruptive and detrimental effects on the oocyte, granulosa and immune cells. Negative nutrient balance is associated with changes in the pattern of ovarian follicle growth which can indirectly affect oocyte quality. Some of this disruption seems to be the result of endocrine and biochemical changes that alter the micro- environment of the growing and maturing oocyte. In addition, cows under negative nutrient balance have extended periods of anovulation. Postpartum anestrus, as well as infertility, is magnified by losses of body condition during the early postpartum period. The underlying mechanism for resumption of ovulatory cycles seems to be associated with metabolic signals and regulatory hormones primarily insulin and insulin- like growth factor (IGF)-1, which link nutritional status with gonadotropin secretion, recoupling of the growth hormone-IGF system, and follicle maturation and ovulation. Feeding diets th at promote increases in plasma glucose and insulin may improve the metabolic and endocrine status of cows in early lactation. Furthermore, fertility in postpartum cows is also determined by uterine health. Reductions in circulating concentrations of Ca and antioxidant vitamins around parturition are also linked with impaired immune competence and result in greater risk of uterine diseases that impair reproduction. Specific nutrients and dietary ingredients have been implicated to affect reproduction in cattle. Excess intake of dietary protein has been suggested as detrimental to fertility, although feeding excess of dietary protein can no longer be justified. Addition of moderate amounts of supplemental fat to the diet improves caloric intake, modulates prostaglandin F2  secretion by the uterus, affects ovarian dynamics, enhances luteal function and embryo quality, and has moderate positive effects on fertility. More specifically, some fatty acids might impact fertilization rate and embryo quality in dairy cows. On the contrary, some dietary ingredients, such as gossypol, when ingested in large quantities decrease fertility of dairy cows because of its negative effects on embryo quality and pregnancy maintenance.(AU)

Simultaneous mode A and mode B echobiometry of senile cataractous eyes in dogs / Ecobiometria simultânea em modos A e B de olhos acometidos por catarata senil, em cães

The evaluation of lens by ultrasonography, previously to phacoemulsification, can offer relevant information, markedly such as aspects and dimensions, allowing design safer surgical strategies with enhanced outcomes. Within the contents of this research, the biometry was performed in lens of dogs with senile immature, mature, and diabetic cataracts, previously to phacoemulsification, using mode A and mode B ultrasonography, simultaneously. The values obtained for axial diameter of the eyes, anterior chamber, lens, and vitreous chamber were, respectively, 19.22mm, 2.35mm, 7.94mm, and 8.94mm. Diabetic cataractous lens were larger (8.90mm), compared to mature cataract (8.12mm). Lens with immature cataract were smaller in dimension than those with mature and diabetic cataracts.(AU)

A avaliação da lente pela ultrassonografia, previamente à facoemulsificação, pode fornecer informações relevantes, notadamente, quanto ao seu aspecto e dimensões, que permitem delinear estratégias cirúrgicas mais seguras e com melhores resultados. Nesta pesquisa, realizou-se a biometria da lente de cães acometidos por catarata senil imatura, madura ou diabética, previamente à facoemulsificação, valendo-se da ultrassonografia em modo A e B, simultaneamente. Os valores obtidos para o diâmetro axial do bulbo do olho, câmara anterior, lente e câmara vítrea foram, respectivamente, 19,22mm, 2,35mm, 7,94mm e 8,94mm. Lentes cataratogênicas pertencentes a animais diabéticos apresentaram dimensões maiores (8,90mm), comparativamente àquelas que apresentavam catarata madura (8,12mm). Lentes acometidas por catarata imatura apresentaram menor dimensão (7,06mm), comparativamente às demais.(AU)

Monogenoidea (Dactylogyridae) em tilápias-do-nilo cultivadas sob diferentes densidades de estocagem em tanques-rede / Monogenoidea (Dactylogyridae) in Nile tilapia cultured under different stocking densities in cages

Avaliaram-se a prevalência e a intensidade de infecção por Monogenoidea em tilápias-do-nilo (Oreochromis niloticus) cultivadas sob diferentes densidades de estocagem em tanques-rede de 4m³. O delineamento experimental foi inteiramente ao acaso, com quatro tratamentos - densidades (D) de D1=250, D2=300, D3=350 e D4=400 peixes/m³, três repetições por tratamento, utilizando-se 360 peixes capturados e analisados no período de fevereiro a junho de 2003. Os parâmetros físico-químicos da água foram mensalmente monitorados. Observaram-se prevalências de 52,8; 62,5; 69,4; 83,3; 58,3 por cento e intensidade média parasitária de 112,8; 65,7; 274,0; 97,8; 100,2 de Dactylogyrus sp. (Monogenoidea: Dactylogyridae). Não houve relação da prevalência e intensidade de infecção com a densidade de cultivo, porém foi verificado efeito quadrático (P<0,05) da intensidade parasitária em função do mês. Verificaram-se maior intensidade média de infecção (274) e elevada prevalência (83,3 por cento) nos meses em que a temperatura e a transparência da água oscilaram abaixo dos limites recomendados para o conforto térmico e bem-estar das tilápias.(AU)

The prevalence and infection intensity of Monogenoidea in Nile tilapia (Oreochromis niloticus) cultivated under different stocking densities in 4m³ cages were evaluated. The experiment was designed in sample random sampling with four treatments - densities (D) of D1=250, D2=300, D3=350, and D4=400 fish/m³- and three repetitions, using 360 fish captured and analyzed during the period from February to June 2003. Physiochemical parameters of the water were monthly monitored. Prevalences of 52.8; 62.5; 69.4; 83.3; and 58.3 percent and parasitic mean intensities of 112.8; 65.7; 274.0; 97.8; and 100.2 Dactylogyrus sp. (Monogenoidea: Dactylogyridae) were observed. No relationship between the prevalence and infection intensity with the cultivation density was found. However, quadratic effect was verified (P<0.05) related to the parasitic intensity in function of the month. High mean intensity of infection (274) and high prevalence (83.3 percent) were verified in the months in that the temperature and the transparency of the water oscillated below the recommended limits for the thermal comfort and well-being of tilapia.(AU)

Evaluation of experimental vaccination of white pekin ducks (anas platyrhynchos) against newcastle disease

ABSTRACT This study aimed the characterization of the importance of vaccination against Newcastle disease of white Pekin duck (Anas platyrhynchos). There were used 120 Pekin ducks, distributed at random into 4 groups, vaccinated or not. At 60 days of age, all groups were challenged with a pathogenic virus (NDV) suspension, EID50 = 108.15/0.1 mL and a group of Specific Pathogen Free (SPF) chicks were used as control of the virus. Cloacal and tracheal swabs from each bird were collected after 6, 14, 20 and 30 days post-challenge for viral isolation in SPF embryonated eggs. White Pekin ducks of all groups did not demonstrate symptoms of the Newcastle Disease (ND). They were refractory to the ND clinical disease. In Pekin ducks from control group, the viral isolation was obtained from 20 up to 30 days after challenge. The NDV isolation was possible in 100% of SPF chicks that died after challenge with ND clinical signs, suggesting the possible state of carrier of NDV by Pekin ducks. In vaccinated groups, the viral isolation was null. It was also demonstrated therefore the relevance of the vaccination to control the virus dissemination by white Pekin ducks infected with NDV.

RESUMO O objetivo do trabalho foi estudar a importância da vacinação de marrecos de Pequim (Anas platyrhynchos) contra a Doença de Newcastle (DN). Foram utilizados 120 marrecos, distribuídos aleatoriamente em 4 grupos, vacinados ou não. Aos 60 dias de idade, todos os grupos foram desafiados com uma suspensão de vírus patogênico (VDN), EID50 = 108,15/0,1 mL e um grupo de aves livres de patógenos específicos (SPF) foi utilizado como controle do vírus . Suabes cloacais e traqueais foram colhidos após 6, 14, 20 e 30 dias após o desafio para isolamento viral, realizado em ovos embrionados SPF. Os marrecos de Pequim de nenhum dos grupos demonstraram sinais clínicos da DN, mostrando-se refratários à doença clínica. Nos marrecos do grupo controle, o isolamento viral foi positivo de 20 até 30 dias após o desafio, sugerindo o possível estado de portador do VDN pelos marrecos de Pequim. Foi realizado o isolamento viral em 100% das aves SPF, que apresentaram sinais clínicos e vieram a óbito após o desafio com o VDN. Nos grupos vacinados, o isolamento do VDN foi nulo. Tais dados demonstraram a importância da vacinação para o controle da disseminação do vírus pelos marrecos de Pequim infectados pelo VDN.

Soroprevalência e fatores de risco para a leptospirose em cães de Campina Grande, Paraíba / Soroprevalence and risk factors for leptospirosis in dogs from Campina Grande, State of Paraíba, Brazil

Investigou-se a prevalência de leptospirose em cães da cidade de Campina Grande, PB, e realizou-se um estudo de fatores de risco para a infecção. Foram examinadas 285 amostras de soro sangüíneo de cães colhidas durante a campanha de vacinação anti-rábica animal, conduzida em setembro de 2003. O diagnóstico da leptospirose foi realizado pela técnica de soroaglutinação microscópica, utilizando-se uma coleção de 22 sorovares. Para a caracterização do sorovar mais provável, levou-se em conta a titulação e a freqüência. A prevalência encontrada foi de 21,4% (IC 95% = 16,8%-26,6%), com maior freqüência dos sorovares autumnalis (7,4%), copenhageni (6%) e canicola (2,1%). A análise de regressão logística multivariada mostrou que os fatores de risco para a leptospirose foram: idade superior a um ano (odds ratio = 3,00; P = 0,006), raça não definida (odds ratio = 4,02; P = 0,011) e ocorrência de enchentes (odds ratio = 2,32; P = 0,039).

The prevalence of leptospirosis was investigated in dogs from Campina Grande city, State of Paraíba, Brazil, and the risk factors for infection were analyzed. Two hundred and eighty five blood samples were collected from dogs during the rabies vaccination campaign, in September 2003. The diagnostic method run for leptospirosis was the microscopic agglutination test, using a batch of 22 leptospiral serovars. The most prevalent serovar was found crossing the results of frequency and titer of agglutinins. The prevalence was 21.4% (95% CI = 16.8%-26.6%) and most frequent reactant serovars were autumnalis (7.4%), copenhageni (6%) and canicola (2.1%). The multivariate logistic regression analysis showed that the risk factors for leptospirosis were: age older than one year (odds ratio = 3.00; P = 0.006), mixed breed (odds ratio = 4.02; P = 0.011) and occurrence of floods in the area (odds ratio = 2.32; P = 0.039).

Soroprevalência e fatores de risco para a leptospirose em cães de Campina Grande, Paraíba / Soroprevalence and risk factors for leptospirosis in dogs from Campina Grande, State of Paraíba, Brazil

Investigou-se a prevalência de leptospirose em cães da cidade de Campina Grande, PB, e realizou-se um estudo de fatores de risco para a infecção. Foram examinadas 285 amostras de soro sangüíneo de cães colhidas durante a campanha de vacinação anti-rábica animal, conduzida em setembro de 2003. O diagnóstico da leptospirose foi realizado pela técnica de soroaglutinação microscópica, utilizando-se uma coleção de 22 sorovares. Para a caracterização do sorovar mais provável, levou-se em conta a titulação e a freqüência. A prevalência encontrada foi de 21,4% (IC 95% = 16,8%-26,6%), com maior freqüência dos sorovares autumnalis (7,4%), copenhageni (6%) e canicola (2,1%). A análise de regressão logística multivariada mostrou que os fatores de risco para a leptospirose foram: idade superior a um ano (odds ratio = 3,00; P = 0,006), raça não definida (odds ratio = 4,02; P = 0,011) e ocorrência de enchentes (odds ratio = 2,32; P = 0,039).(AU)

The prevalence of leptospirosis was investigated in dogs from Campina Grande city, State of Paraíba, Brazil, and the risk factors for infection were analyzed. Two hundred and eighty five blood samples were collected from dogs during the rabies vaccination campaign, in September 2003. The diagnostic method run for leptospirosis was the microscopic agglutination test, using a batch of 22 leptospiral serovars. The most prevalent serovar was found crossing the results of frequency and titer of agglutinins. The prevalence was 21.4% (95% CI = 16.8%-26.6%) and most frequent reactant serovars were autumnalis (7.4%), copenhageni (6%) and canicola (2.1%). The multivariate logistic regression analysis showed that the risk factors for leptospirosis were: age older than one year (odds ratio = 3.00; P = 0.006), mixed breed (odds ratio = 4.02; P = 0.011) and occurrence of floods in the area (odds ratio = 2.32; P = 0.039).(AU)