Resumen 16. Helicobacíer sp, bacilo Gram negativo, se encuentra asociado a gastritis, úlcera y cáncer gástrico.La prevalencia mundial de la infección por H. pylori es mayor al 50%, constituyendo un problema de salud pública. Diferentes especies de Helicobacter afectan tanto a animales como seres humanos, pudiendo ser responsables de zoonosis. El proceso de colonización de esta bacteria depende en gran medida de su unión a glicoconjugados presentes en la mucosa gástrica del hospedero. El cerdo representa el modelo animal de elección para el estudio de la infección por esta bacteria. El objetivo del presente trabajo fue analizar el comportamiento del glicoconjugado glucosa/manosa en la mucosa gástrica de cerdos afectados por gastritis producida por Helicobacter sp. Se utilizaron muestras de la región antral del estómago de cerdos mestizos, obtenidas de frigoríficos de Río Cuarto (Argentina). Dichas muestras fueron clasificadas en distintos grupos de estudio de acuerdo al tipo de gastritis y a la presencia y/o ausencia de Helicobacter sp. Las muestras fueron luego sometidas a lectin-histoquímica para la marcación del glicoconjugado glucosa/manosa y posteriormente evaluadas mediante microscopía óptica y análisis estadístico. Los resultados obtenidos indican que no hay diferencias entre los grupos en cuanto a la expresión de glucosa/manosa en epitelio y glándulas gástricas, pero sí se presentan diferencias significativas en la expresión de este glicoconjugado en lamina propia entre el grupo gastritis aguda positivo a Helicobacter sp con respecto a los grupos gastritis aguda negativo a Helicobacter sp. y grupo con mucosa normal. Los resultados estadísticos revelan que existe relación entre el aumento en la marcación de glucosa/manosa y la presencia de Helicobacter sp en lamina propia de mucosa gástrica de cerdos.

Abstract 20. Helicobacter pylori, a Gram negative bacillus, is associated with gastritis, ulcer, and gastric cáncer. The worldwide prevalence of H. pylori infection is greater than 50%, constituting a public health problem. Different species of Helicobacter were described, which affect both animáis and humans, and may be responsible for zoonoses. The colonization process of this bacterium depends largely on its binding to glycoconjugates present in the gastric mucosa of the host. The pig represents the animal model of choice for the study of infection by this bacterium. The objective of the present work was to analyze the behavior of the glucose/mannose glycoconjugate in the gastric mucosa of pigs affected by gastritis caused by Helicobacter sp. Samples from the antral región of the stomach of crossbred pigs were used, obtained from slaughterhouse in the Río Cuarto (Argentina). The samples were classified into different study groups according to the type of gastritis and the presence or absence of Helicobacter sp. A lectin histochemistry study for glucose/mannose glycoconjugate was carried out, the evaluated under microscope and statistical analysis performed. The results obtained indícate that there were no significant differences between the groups in the glucose/mannose expression in epithelium and gastric glands, but there were significant differences in the expression of this glycoconjugate in lamina propria between Helicobacter sp positive acute gastritis with respect to the Helicobacter sp negative acute gastritis groups and with normal mucosa group. This results reveal that there is relationship between the increase in glucose/mannose expression and the presence of Helicobacter sp in the lamina propria of pig gastric mucosa.

Edible and/or biodegradable films usually have limited water vapor barriers, making it difficult to use them. Thus, the objective of this work was to evaluate the effect of a chemical reticulation treatment with formaldehyde and glyoxal on the mechanical properties, water vapor permeability, solubility and color parameters of gelatin-based films. Formaldehyde and glyoxal were added to the filmogenic solution in concentrations ranging from 3.8 to 8.8 mmoles/100 mL of filmogenic solution and 6.3 to 26.3 mmoles/100 mL of filmogenic solution, respectively. The treatments caused a reduction in permeability to water vapor and in solubility. Only the treatment with formaldehyde caused a significant increase in rupture tension for concentrations above 6.3 mmoles/100 mL of filmogenic solution. Scanning electron microscopy indicated a loss of matrix orientation due to the chemical reticulation treatment.

The objective of this research was to develop and characterize composite biofilms produced using wheat gluten and cellulose acetate phthalate. Biofilms act as barriers to moisture and oxygen diffusion through the film. The films were prepared with different thicknesses and component concentrations and were analyzed for water vapor and oxygen permeabilities, water and acid solubilities and mechanical properties. Results showed that the mixture improved film characteristics more than each of the individual components alone. The 1:1 mixture had properties of better permeability to water and oxygen. The composite films were completely soluble in water and acid, with the exception of the film with the highest gluten concentration, which was 50% soluble in water and acid. An increase in gluten concentration in the composite films resulted in a decrease in tensile strength. There was no significant difference in elongation at break between the composite films. No difference in thickness was detected either. Results showed that the mixture improved the characteristics more than of the individual components alone.