RESUMO

AIMS: The present study aims to determine the phototoxic and haemolytic activity of organophosphorus. The use of alternative in vitro assays with human erythrocytes is suggested to predict the polluting effect of these products on health. METHODOLOGY: Human erythrocytes from Toluca Blood Bank were used. Sodium dodecyl sulfate was employed as a positive control. Additionally, the haemolysis percentage of three organophosphate (Acetate, Chlorpyrifos, Malathion, Methamidophos, Methyl Parathion) induced photo haemolysis formulated with surfactants on a concentration of 2 x 109 erythrocytes were evaluated. Finally, the products were classified as irritant or phototoxic. RESULTS: Results showed that the HC50 red blood cells were similar for each organophosphate (Malathion and Methamidophos) indicating very irritant action with ratio classification (L/D) of 0.041 and 0.053, respectively. On the other hand, Chlorpyrifos was classified as an irritant with L/D= 0.14. On the other hand, the HC50 obtained photo hemolysis assays irradiated red blood cells was similar for each organophosphate (Acetate, Chlorpyrifos, Malathion, Methamidophos, Methyl Parathion) indicating no phototoxic action. CONCLUSION: As a conclusion, it can be said that the parameters of haemolysis and denaturation of proteins are good indicators to classify organophosphorus formulated with surfactants as irritating or phototoxic.

Assuntos

RESUMO

Drug-resistant Salmonella is frequently detected in most parts of the world, and its rate of resistance has increased significantly in recent years. However, this study aimed to evaluate the minimum inhibitory concentration (MIC, determined with the Kirby-Bauer method) of quinolones in 86 Salmonella spp. strains isolated from pigs. Both the inside and outside of the QRDR region of strains were sequenced. The DNA sequence of the QRDR region of Salmonella spp. revealed the mutations S83F, D87N and S83Y. The region outside the QRDR showed a mutation in L582G. Forty-five isolates of Salmonella ssp. were categorized as quinolone-resistant; out of these, 16 corresponded to Salmonella enterica and isolates showed intermediate resistance (6.25%) to nalidixic acid. Three isolats (18.6%) were resistant to ampicillin; two (12.5%) were resistant to carbenicillin. Moreover, three (18.7%) isolates were resistant to gentamicin, nitrofurantoin and pefloxacin, and 8 (50%) were resistant to trimethoprim/sulfamethoxazole. Six percent of Salmonella spp. strains showed less resistance to antimicrobial agents compared to S. Thyphimurium (18%). The resistance to individual quinolones varied by serotypes. For S. anatum and S. Reading, it was 12.25%, and for S. choreaeaesuis, S. typhimurium monofasica, 6.25%. In contrast, S. agona, S. bredeney and S. london were sensitive to these antibiotics. In conclusion, quinolones have become the drugs of choice for the treatment of severe Salmonella infections. The study of mutations outside the QRDR region opens up new insights about the resistance of Salmonella to fluoroquinolones.

Assuntos

RESUMO

The objective of the present study was to simulate the effect of the seasonal variation of climate on the nutritional value and dry matter yield of star grass and its capacity to support milk production alone or with concentrate supplementation in small-scale milk production systems in the tropical regions of Mexico. Two mathematical simulation models were used, the first model simulates the growth and yield of star grass (Cynodon plectostachyus), and the second model simulates the productive performance of dairy cows. Both models were integrated in a decision-making support system (DSSTROP). Model's predictions were validated by a calibration exercise for each data set from three experiments on the effect of concentrate supplementation on milk yield. The DSSTROP predictions and the results from the experiments were compared by regression analysis. The results suggest that the DSSTROP adequately predicts milk production (R2=0.74). The DSSTROP predictions suggest that milk production based solely on star grass may occur only between June to August. The highest milk yield (8.5kg cow-1 day-1) sustained solely on grass was achieved in June, followed by lower yields of 5kg cow-1 day-1 in July and August. Milk production without concentrates can be explained by the positive effects of the rain observed during June to August on grass growth, and to the fact that grass quality is best at the beginning of the rainy season. It is concluded that June to August is the best time of the year for milk production base solely on grass. It also was concluded that the use of large quantities of concentrates by farmers may be justified because milk production with star grass alone may not be possible especially during the dry season.

O objetivo do presente trabalho foi simular o efeito da variação sazonal do clima sobre o valor nutritivo e a produção de matéria seca do capim-estrela e a sua capacidade de apoiar a produção de leite, com ou sem suplementação concentrada, nos sistemas de produção de leite em pequena escala, nas regiões tropicais da região central do México. Foram utilizados dois modelos de simulação, o primeiro modelo simula o crescimento e produção de grama estrela (Cynodon plectostachyus), e o segundo modelo simula o desempenho produtivo de vacas leiteiras. Ambos os modelos foram integrados em um sistema de apoio à tomada de decisão para a produção de leite em regiões de clima tropical (DSSTROP). Previsões do modelo foram validadas por um exercício de calibração, para os quais foram utilizados dados de três experimentos sobre o efeito da suplementação concentrada na produção de leite. As previsões do DSSTROP e os dados obtidos foram comparados através de análise de regressão. Os resultados sugerem que o DSSTROP prevê adequadamente a produção de leite (R2=0,74) para as três experiências simuladas. As previsões DSSTROP sugerem que a produção de leite com base exclusivamente na grama estrela pode ocorrer apenas entre junho a agosto. A maior produção de leite (8,5kg vaca-1 dia-1), sustentada unicamente na grama foi alcançada em junho, seguido por rendimentos mais baixos de cerca de 5kg vaca-1 dia-1, em julho e agosto. O período de produção de leite sem concentrado pode ser explicado pelos efeitos positivos da chuva, observada durante junho-agosto no crescimento do pasto, e devido ao fato de que o valor nutritivoé melhor no início da estação chuvosa. Conclui-se que entre junho-agosto é a melhor época do ano para a base de produção de leite exclusivamente com pasto. Além disso, o uso de grandes quantidades de concentrados pelos agricultores na área de estudo se justifica, pois produção de leite somente com grama estrela não é possível e talvez nem aconselhável.

Assuntos

RESUMO

The objective of the present study was to simulate the effect of the seasonal variation of climate on the nutritional value and dry matter yield of star grass and its capacity to support milk production alone or with concentrate supplementation in small-scale milk production systems in the tropical regions of Mexico. Two mathematical simulation models were used, the first model simulates the growth and yield of star grass (Cynodon plectostachyus), and the second model simulates the productive performance of dairy cows. Both models were integrated in a decision-making support system (DSSTROP). Model's predictions were validated by a calibration exercise for each data set from three experiments on the effect of concentrate supplementation on milk yield. The DSSTROP predictions and the results from the experiments were compared by regression analysis. The results suggest that the DSSTROP adequately predicts milk production (R2=0.74). The DSSTROP predictions suggest that milk production based solely on star grass may occur only between June to August. The highest milk yield (8.5kg cow-1 day-1) sustained solely on grass was achieved in June, followed by lower yields of 5kg cow-1 day-1 in July and August. Milk production without concentrates can be explained by the positive effects of the rain observed during June to August on grass growth, and to the fact that grass quality is best at the beginning of the rainy season. It is concluded that June to August is the best time of the year for milk production base solely on grass. It also was concluded that the use of large quantities of concentrates by farmers may be justified because milk production with star grass alone may not be possible especially during the dry season.(AU)

O objetivo do presente trabalho foi simular o efeito da variação sazonal do clima sobre o valor nutritivo e a produção de matéria seca do capim-estrela e a sua capacidade de apoiar a produção de leite, com ou sem suplementação concentrada, nos sistemas de produção de leite em pequena escala, nas regiões tropicais da região central do México. Foram utilizados dois modelos de simulação, o primeiro modelo simula o crescimento e produção de grama estrela (Cynodon plectostachyus), e o segundo modelo simula o desempenho produtivo de vacas leiteiras. Ambos os modelos foram integrados em um sistema de apoio à tomada de decisão para a produção de leite em regiões de clima tropical (DSSTROP). Previsões do modelo foram validadas por um exercício de calibração, para os quais foram utilizados dados de três experimentos sobre o efeito da suplementação concentrada na produção de leite. As previsões do DSSTROP e os dados obtidos foram comparados através de análise de regressão. Os resultados sugerem que o DSSTROP prevê adequadamente a produção de leite (R2=0,74) para as três experiências simuladas. As previsões DSSTROP sugerem que a produção de leite com base exclusivamente na grama estrela pode ocorrer apenas entre junho a agosto. A maior produção de leite (8,5kg vaca-1 dia-1), sustentada unicamente na grama foi alcançada em junho, seguido por rendimentos mais baixos de cerca de 5kg vaca-1 dia-1, em julho e agosto. O período de produção de leite sem concentrado pode ser explicado pelos efeitos positivos da chuva, observada durante junho-agosto no crescimento do pasto, e devido ao fato de que o valor nutritivoé melhor no início da estação chuvosa. Conclui-se que entre junho-agosto é a melhor época do ano para a base de produção de leite exclusivamente com pasto. Além disso, o uso de grandes quantidades de concentrados pelos agricultores na área de estudo se justifica, pois produção de leite somente com grama estrela não é possível e talvez nem aconselhável.(AU)

Assuntos

RESUMO

Tropical grasses are the primary nutrient resource for cattle production in the tropics, and they provide low-cost nutrients to cattle. However, its production is constrained by seasonal changes and quality; hence, appropriate usage of relatively inexpensive agricultural by-products is important to profitable livestock production. The objective of the study was to evaluate the effect of supplementing coffee pulp to dairy cows grazing tropical grasses on milk yield and forage intake. Four multiparous crossed Holstein-Brown Swiss-Zebu cows of similar weight and milk yield were used. The effect of 10%, 15% and 20% inclusion of coffee pulp in dairy concentrates on milk yield and forage intake was analysed using a 4 × 4 Latin square design. Results showed that there were no significant effects (P > 0.05) in grass dry matter intake, milk yield, milk composition body weight and body condition score due to the inclusion of coffee pulp in the dairy concentrates. It is concluded that coffee pulp can be included at levels of 20% in the concentrate without compromising significantly (P > 0.05) milk yield, milk composition and grass dry matter intake. It also was concluded that cost of concentrate is reduced in 20% by the inclusion of coffee pulp.

Assuntos

RESUMO

Parkinson's disease is considered a neurodegenerative disorder, which involves environmental factors in the etiology of the disease. Such as chemical agents with neuromolecular effect among which is the MPTP (1-methyl-4-phenyl-1, 2, 3, 6 tetra-hydropyridine), MPP (1-methyl-4-phenyl hypyridinium), paraquat, the latter used as a herbicide in the agricultural fields of our country. It has been documented in epidemiological and experimental studies the association of occupational exposure to paraquat and Parkinson's disease. The aim of this paper is to describe a clinical case of occupational medicine in Parkinson's disease in occupationally exposed workers to paraquat, elevating the importance of medical history work, which was the key to the clinical case study.

Assuntos

RESUMO

El aumento de la longevidad (hoy 71 años internacionalmente) aumenta el número de casos de carcinoma prostático. A mayor edad, mayor posibilidad. El tacto rectal tiene para el hombre la misma utilidad que el examen ginecologico en la prevención del carcinoma cervical. El antigeno prostático (PSA) es un signo semiológico máas en el estudio de la próstata, que solo el urólogo está en capacidad de darle correcta interpretación. Todo individuo mayor de 50 años debe controlar su antígeno cada 6 meses y en caso de alteración, visitar al urólogo para su complemento. Un aumento de 0.75 ng/ml verificando en el laboratorio anterior, en el transcurso de un año, es signo de alerta para el paciente. Cifras superiores a 4 ng/ml se deben esclarecer con la relación antígeno libre/antígeno total. La relación, solo tiene utilidad cuando la cifra del PSA total excede los 4.0 ng/ml entre 4 y 10 ng/ml, la relacion evita biopsias inutiles. Se considera una relación normal del 25 porciento. Si es inferior a 10 porciento hay 80 porciento de posibilidades de corresponder a carcinoma. En el carcinoma de próstata el PSA se eleva a base del complejo PSA-ACT. La densidad del PSA presta una utilidad relativa. Los otros métodos descritos ofrecen mayor facilidad al paciente. La biopsia es el unico sistema que en forma categorica diagnostica el carcinoma. El ultrasonido transrectal es de gran utilidad para orientar la toma de la biopsia

Assuntos

Assuntos

Assuntos

Assuntos

Assuntos

Assuntos

Assuntos

Assuntos

Assuntos

Assuntos

Assuntos

Assuntos

RESUMO

El magnesio es un catión divalente, esencial en el metabolismo del organismo y sus alteraciones causan múltiple sintomatología, a veces atribuida a otras enfermedades. El exceso de magnesio produce principalmente astenia, paresias, arreflexia, bradicardia e hipotensión. El déficit se manifiesta principalmente con temblores, tetania, convulsiones, alucinaciones y ansiedad. Un adecuado diagnóstico de alteración de este ión es indispensable para el correcto tratamiento de todo paciente con alteración del equilibrio hídrico y electrolítico. En el presente artículo el autor establece los criterios clínicos y paraclínicos indispensables para un adecuado manejo de las alteraciones de este ión, frecuentemente olvidados en la práctica clínica.

Assuntos

RESUMO

El carcinoma de próstata es la neoplasía más frecuente y la segunda causa de muerte por enfermedades neoplasicas en el sexo masculino. Hasta hace un tiempo el único método diagnóstico fiable se basaba en la presencia de alteraciónes al examen rectal. Actualmente existen métodos complementarios de laboratorio utiles para el tamizaje de pacientes con enfermedad prostática que permiten seleccionar aquellos pacientes en quienes su riesgo justifica otros estudios mas avanzados como la ecografía y la biopsia prostática dirigida.

Assuntos