Immunological assessment of plant-derived avian flu H5/HA1 variants.

Polypeptide variants of the HA1 antigenic domain of the H5N1 avian influenza virus hemagglutinin (HA) molecule were produced in plants using transient and stable expression systems and fused with His/c-myc tags or with mouse or human Fc antibody fragments. The resulting peptides were purified and used for intramuscular immunization of mice. While the recombinant HA1 variants induced a significant serum humoral immune response in the mice, none of the HA1 preparations induced virus-neutralizing antibodies. Fusion with the Fc fragment improved overall yield of the constructs and allowed purification requiring only a single step, but led to no detectable fusion-related enhancement of immunogenicity or quality of immune response

Factores de Riesgo Asociados a la Seroprevalencia de Neospora caninum en Bovinos Naturalmente Infectados en la Ceja de Selva de Oxapampa, Perú

The aim of the present study was to determine the risk factors associated with the seroprevalence ofNeospora caninum in naturally infected bovine in the tropical highlands of Oxapampa, Peru. The study was carried out in 20 herds in Chontabamba and Oxapampa districts. Blood samples were collected from 388 animals older than 6 months of age, and a survey was conducted to identify potential risk factors in the herds. The presence of antibodies against N. caninum was done by the c-ELISA test using a commercial kit. The association between seroprevalence of N. caninum and the variables evaluated (age group, origin, herd size, disposal of animal remains, number of dogs per herd) were analyzed by the logistic regression. The seroprevalence ofN. caninum was 18.8 ± 3.9%. The risk factors associated with seroprevalence ofN. caninum in bovine were the presence of more than three dogs in the herd, the disposal of animal remains in the environment and a herd size larger than 10 animals (p<0.05), whereas age and origin did not influence the presence of N. caninum.El objetivo del estudio fue determinar los factores de riesgo asociados a la seroprevalencia de Neospora caninum en bovinos naturalmente infectados en la ceja de selva de Oxapampa, Perú. El trabajo se desarrolló en 20 hatos ganaderos de los distritos de Chontabamba y Oxapampa. Se obtuvieron muestras de sangre de 388 bovinos mayores de 6 meses, y mediante una encuesta se levantó información situacional y epidemiológica de las ganaderías para identificar los potenciales factores de riesgo. La presencia de anticuerpos contra N. caninum se determinó mediante la técnica de ELISA de competencia (cELISA), utilizando un kit comercial. La asociación entre la seroprevalencia a N. caninum y las variables evaluadas (grupo etario, procedencia, tamaño del hato, eliminación de restos de animales muertos y número de perros por hato) se analizaron mediante regresión logística. Se encontró una seroprevalencia de 18.8 ± 3.9%. Los factores de riesgo asociados con la seropositividad de N. caninum fueron la presencia de más de tres perros en el hato, la eliminación de restos de animales muertos al aire libre y un tamaño de hato mayor a 100 animales (p<0.05), en tanto que la edad y procedencia no influyeron en el riesgo de presentación de N. caninum

Efecto del resveratrol en el porcentaje y calidad de embriones in vitro generados por separación de blastómeras en bovinos

The oxidative state is an important factor that determines the development of bovine embryos. The objective in this study was to evaluate the effect of resveratrol on the quality of in vitro embryos generated by separation of blastomeres in cattle. Oocytes from the slaughterhouse were matured and fertilized in vitro by the conventional method. After 18 hours of fertilization, the zygotes were cultured for 3 days in synthetic oviductual fluid medium (SOF) for control and supplemented with 2 μM and 0.5 μM for the treatments. On day 3 they were stripped of their zona pellucida (ZP) to be cultivated at a rate of four blastomeres in well of the well (WOW) for 6 days in medium SOF supplemented with resveratrol. We evaluated percentage data of cleavage and embryonic division (8 to 10 blastomeres) after 3 days of culture, finding a significant difference p<0.05 with supplementation with 0.5 μM of resveratrol. At 6 days after blastomeres separation, percentage of embryos, number of total cells, live cells and dead cells were evaluated using Hoechst, FDA and PI staining respectively. There were no differences in the percentage of blastocysts between treatments; however, supplementation with 0.5 μM of resveratrol to the SOF medium had a greater amount of total cells and living cells (p<0.05). In conclusion, supplementation with resveratrol in the SOF medium does not increase the percentage of blastocysts but improves its quality using a concentration of 0.5 μM.El estado oxidativo es un factor importante que determina el desarrollo de embriones bovinos. El objetivo de este estudio fue evaluar el efecto del resveratrol en el porcentaje y calidad de embriones in vitro generados por separación de blastómeras en ganado bovino. Ovocitos provenientes de matadero fueron madurados y fecundados in vitro por el método convencional. Terminada las 18 horas de fecundación, los cigotos se cultivaron por 3 días en medio fluido oviductual sintético (SOF) para el control y suplementado con 2 µM y 0,5 µM para los tratamientos. Al día 3 se despojaron de su zona pelúcida (ZP) para ser cultivados a razón de cuatro blastómeras en well of thewell (WOW) por 6 días en medio SOF suplementado con resveratrol. Se evaluaron datos porcentuales de clivaje y división embrionaria (8 a 10 blastómeros) a los 3 días de cultivo superando la suplementación con 0.5µM de resveratrol (p<0,05). A los 6 días post separación de blastómeras se evaluó porcentaje de embriones, cantidad de células totales, células vivas y células muertas, utilizando la tinción Hoechst, FDA y PI respectivamente. No hubo diferencias en el porcentaje de blastocistos entre tratamientos; sin embargo, la suplementación con 0,5 µM de resveratrol al medio SOF tuvo mayor cantidad de células totales y células vivas (p<0,05). Finalmente la suplementación con resveratrol al medio SOF no aumenta el porcentaje de blastocistos pero sí mejora su calidad usando una concentración de 0,5 µM

Avaliação das propriedades físico hídricas do solo em um programa de pagamento por serviços ambientais: Produtores de Água e Floresta sub-bacia do rio Sacra Família (RJ).

O presente trabalho busca através de análises laboratoriais estimar o grau de impacto do restauro florestal promovido pelo Produtores de Água e Floresta na sub-bacia do rio Sacra Família (RJ) comparando resultados após um ano de estabelecimento dos plantios sobre propriedades físico hídricas do solo, como: a textura, densidade de partículas, densidade do solo, porosidade e a estabilidade de agregados

Limits to the energy resolution of a single Air Cherenkov Telescope at low energies

The photon density on the ground is a fundamental quantity in all experiments based on Cherenkov light measurements, e.g. in the Imaging Air Cherenkov Telescopes (IACT). IACT's are commonly and successfully used in order to search and study Very High Energy (VHE) gamma-ray sources. Difficulties with separating primary photons from primary hadrons (mostly protons) in Cherenkov experiments become larger at lower energies. I have calculated longitudinal and lateral density distributions and their fluctuations at low energies basing on Monte Carlo simulations (for vertical gamma cascades and protonic showers) to check the influence of the detector parameters on the possible measurement. Relative density fluctuations are significantly higher in proton than in photon induced showers. Taking into account the limited detector field of view (FOV) implies the changes of these calculated distributions for both types of primary particles and causes an enlargement in relative fluctuations. Absorption due to Rayleigh and Mie scattering has an impact on mean values but does not change relative fluctuations. The total number of Cherenkov photons is more sensitive to the observation height in gamma cascades than in proton showers at low primary energies. The relative fluctuations of the density do not depend on the reflector size in the investigated size range (from 240 m^2 up to 960 m^2). This implies that a single telescope with a mirror area larger than that of the MAGIC telescope cannot achieve better energy resolution than estimated and presented in this paper. The correlations between longitudinal and lateral distributions are much more pronounced for primary gamma-ray than for primary proton showers.Comment: 21 pages, 11 figures, accepted for publication in Journal of Physics

Efecto de dos temperaturas de dilución sobre la calidad de semen en ganado cebuino del Trópico Peruano

The bull is a factor of genetic and economic importance in cattle breed, since the next generations will depend on it; therefore, the evaluation of the seminal quality and the cryopreservation of its genetic ma­terial are essential. The aim of the study was to evaluate the effect of two dilution temperatures on the quality of semen from zebuine cattle from the Peruvian Tropics. The samples were placed in a water bath at 34°C and the macroscopic and microscopic characteristics of semen were analyzed. Only the ejaculates with >60% motility and <20% abnormalities were processed, separating them into two treatments. T1 consisted of a 1:1 predilu­tion at 34°C, followed by a final dilution of 30 minutes by adding the dilutor at 34°C. T2 consisted of a 1:1 predilution at 34°C and after 30 minutes of stabilization, refrigeration was carried out together with the dilutor, in order to carry out the final dilution at 5°C. The seminal quality was analyzed after 16 hours of refrigeration. The percentage of vitality in T1 (80.89%) was greater than in T2 (71.22%) (p<0.05), the positive reaction to the hypoosmotic problem was greater in T1 (71.11%) than in T2 (60%) (p<0.05). Acrosomal integrity and morphometric features did not vary according to treatments. In conclusion, the initial and final dilution at 34°C in Gyr bulls positively influences the semen quality before the freezing of semen packets.El toro es un factor de importancia genética y económica en un hato ganadero, ya que de este dependerán las próximas generaciones; por lo tanto, es esencial la evaluación de la calidad seminal y la criopreservación de su material genético. El objetivo del estudio fue evaluar el efecto de dos temperaturas de dilución sobre la calidad de semen de ganado cebuino del Trópico Peruano. Dos toros Gyr fueron colectados semanalmente mediante electroeyaculación. Las muestras se colocaron en baño maría a 34°C y se analizaron las características macroscópicas y microscópicas del semen. Solo los eyaculados con >60% de motilidad y <20% de anormalidades fueron procesados, separándolos en dos tratamientos. El T1 consistió en predilución 1:1 a 34°C, luego de 30 minutos una dilución final agregando el dilutor a 34°C. El T2 consistió en predilución 1:1 a 34°C y a los 30 minutos de estabilización se llevó a refrigeración conjuntamente con el dilutor, para luego realizar la dilución final a 5°C. La calidad seminal fue analizada luego de 16 horas de refrigeración. El porcentaje de vitalidad en T1 (80,89%) fue mayor que en T2 (71,22%) (p<0,05), la reacción positiva a la prueba hipoosmótica fue mayor en T1 (71,11%) que en T2 (60%) (p<0,05). La integridad acrosomal y los rasgos morfométricos no variaron según tratamientos. En conclusión, la dilución inicial y final a 34°C en toros Gyr influye positivamente sobre la calidad seminal antes de la congelación de pajillas de semen

The role of mast cells in the pathogenesis of pain in chronic pancreatitis

BACKGROUND: The biological basis of pain in chronic pancreatitis is poorly understood. Mast cells have been implicated in the pathogenesis of pain in other conditions. We hypothesized that mast cells play a role in the pain of chronic pancreatitis. We examined the association of pain with mast cells in autopsy specimens of patients with painful chronic pancreatitis. We explored our hypothesis further using an experimental model of trinitrobenzene sulfonic acid (TNBS) -induced chronic pancreatitis in both wild type (WT) and mast cell deficient mice (MCDM). METHODS: Archival tissues with histological diagnoses of chronic pancreatitis were identified and clinical records reviewed for presence or absence of reported pain in humans. Mast cells were counted. The presence of pain was assessed using von Frey Filaments (VFF) to measure abdominal withdrawal responses in both WT and MCDM mice with and without chronic pancreatitis. RESULTS: Humans with painful chronic pancreatitis demonstrated a 3.5-fold increase in pancreatic mast cells as compared with those with painless chronic pancreatitis. WT mice with chronic pancreatitis were significantly more sensitive as assessed by VFF pain testing of the abdomen when compared with MCDM. CONCLUSION: Humans with painful chronic pancreatitis have an increased number of pancreatic mast cells as compared with those with painless chronic pancreatitis. MCDM are less sensitive to mechanical stimulation of the abdomen after induction of chronic pancreatitis as compared with WT. Mast cells may play an important role in the pathogenesis of pain in chronic pancreatitis