Oral tolerance blocks the development of specific immune responses to proteins ingested by the oral route. One of the first registries of oral tolerance showed that guinea pigs fed corn became refractory to hypersensitivity to corn proteins. Mice fed with chow containing corn are tolerant to zein, and parenteral injection of zein plus adjuvant blocks immunization to unrelated proteins injected concomitantly and reduces unspecific inflammation. Extensive and prolonged inflammatory infiltrate in the wound bed is one of the causes of pathological wound healing. Previous research shows that intraperitoneal injection of zein concomitant with skin injuries reduces the inflammatory infiltrate in the wound bed and improves wound healing. Herein, we tested if one subcutaneous injection of zein before skin injury improves wound healing. We also investigated how long the effects triggered by zein could improve skin wound healing. Mice fed zein received two excisional wounds on the interscapular skin under anesthesia. Zein plus Al(OH)3 was injected at the tail base at 10 min, or 3, 5, or 7 days before skin injuries. Wound healing was analyzed at days 7 and 40 after injury. Our results showed that a zein injection up to 5 days before skin injury reduced the inflammatory infiltrate, increased the number of T-cells in the wound bed, and improved the pattern of collagen deposition in the neodermis. These findings could promote the development of new strategies for the treatment and prevention of pathological healing using proteins normally found in the common diet.

Objetivos: el objetivo de la investigación fue aislar protozoarios kinetoplástidos a partir de mamíferos silvestres en tres departamentos de Bolivia, con la finalidad de identificar reservorios de tripanosomátidos que podrían causar infección en diferentes reservorios y enfermedades en el humano. Métodos: Los mamíferos silvestres fueron capturados en el Chaco, valles interandinos y la zona tropical de Bolivia, utilizando trampas Sherman, Havahard y Tomahawk. Los animales capturados fueron anestesiados para realizar el xenodiagnóstico y la extracción de sangre por punción cardiaca; el aislamiento de tripanosomátidos se realizó por hemocultivo utilizando medios de cultivo NNN y su respectiva identificación por las técnicas de PCR-RFLP en el laboratorio de Biología molecular IIBISMED. Resultados: fueron capturados 236 mamíferos silvestres pertenecientes a 30 especies, de las cuales 7 especies presentaron infección por hemoflagelados. Trypanosoma cruzi fue aislado de Didelphis marsupialis, D. albiventris, Galea musteloides, Graomys domorum y Andalgalomis pearsoni; T.c marinkellei y T. dionisii fueron aislados de Carolia perspicillata (murciélagos) y otros kinetoplástidos no identificados por herramientas moleculares disponibles fueron aislados de mamíferos del género Graomys y Andalgalomys, capturados en las provincias Campero de Cochabamba y Cordillera del departamento de Santa Cruz. Conclusiones: El T. cruzi, T.c. marinkellei, T. dionisii y otros tripanosomátidos se encuentran infectando a marsupiales (Didelphis), roedores (Graomys y Andalgalomys) y cobayos silvestres (Galea) los cuales se encuentran en su ciclo silvestre en las zonas estudiadas.

Objectives: The aim of this research was isolate kinetoplastid protozoan from wild mammals in three departments of Bolivia, to identify Trypanosomatids reservoirs that could cause infection in different reservoirs and disease in humans. Methods: The wild mammals were caught in the Chaco, valleys and the tropical zone of Bolivia, using Sherman, Havahard and Tomahawk traps. Captured animals were anesthetized and xenodiagnosis and blood cardiac puncture was performed; trypanosomatides isolation using blood culture was done in NNN culture media and the respective identification was performed by PCR-RFLP techniques in the molecular biology laboratory of IIBISMED. Results: 236 wild mammals belonging to 30 species were captured, of which 7 species showed infection by hemoflagellates. Trypanosoma cruzi was isolated from Didelphis marsupialis, D. albiventris, Galea musteloides, Graomys domorum and Andalgalomis pearsoni; T.c. marinkellei and T. dionisii were isolated from Carolia perspicillata (bats) and other kinetoplastid not identified by available molecular tools were also isolated from Andalgalomys and Graomys mammals genus, from Campero and Cordillera provinces of Cochabamba and Santa Cruz. Conclusions: The T. cruzi, T.c. marinkellei, T. dionisii and other trypanosomatids are infecting marsupials (Didelphis), rodents (Graomys and Andalgalomys) and wild guinea pigs (Galea) which are found in a sylvatic cycle in the studied areas.

Background: The effects of aging on people must be evaluated to adequate sanitary actions. Aim: To assess the characteristics of older subjects living in Antofagasta, Chile. Material and Methods: Cross sectional assessment of 602 subjects without dementia, aged more than 60 years (55% females). A socioeconomic and medical history was obtained and Barthel, Lawton, Yesavage depression, Tromp fall risk and Folstein Mini mental scales were applied. Results: Sixty eight percent of subjects had more than six years of studies. Forty six percent had hypertension, 28% had osteoarticular problems, 20% had hypercholesterolemia and 17% diabetes mellitus. Four percent had depression and falls were reported by 35%. Seventy four percent were independent in basic and instrumental activities. Ninety four percent had normal cognitive functions. Age was an important determinant of functional capacity. Conclusions: The main problems detected in this sample were the risk of falls and the presence of chronic diseases.

This work studied the complex relations of peasant production systems. The study was carried out in Maullín county, X Region of Chile, between 1995 and 1997, where two types of peasant systems were analyzed: surplus and subsistence. The results indicated that the subsistence system generates its cash income with a greater diversity of items than the surplus system. In the subsistence system, the production strategy is based on a high use of self-generated inputs and minimized expenditures for labor and services. The surplus system bases its production strategy on high labor and service expenses, and a high proportion of production for sale; furthermore, what, how, and how much to produce are defined completely in function of the exchange value. On the other hand, decisions in the subsistence system are not totally guided by the market, because an important part of production is related to the food requirements of the family. Also, a high family labor use was observed, with contracting for labor only being made when necessary, in contrast to the surplus system, where only 38% of the work is performed by the family. With respect to capital, large differences between the two systems were observed, which reinforces the view that the production strategy is a reflection of the condition of endowment of given factors rather than the consequence of the specific economic rationality of the peasant family.

Este trabajo estudia las relaciones de los sistemas de producción campesinos. El estudio se realizó en la comuna de Maullín, Décima Región de Chile, entre 1995 y 1997, donde se analizaron dos casos de sistemas campesinos, uno excedentario y otro de subsistencia. Los resultados indican que el tipo subsistencia genera sus ingresos en efectivo con una mayor diversidad de rubros que el tipo excedentario. En el tipo subsistencia la estrategia productiva se basa en el uso de autoinsumos y una baja contratación de mano de obra y servicios, minimizando el desembolso en efectivo. El tipo excedentario basa su estrategia productiva en un alto gasto en mano de obra y servicios, y una alta proporción de la producción dirigida hacia la venta. Además, el qué, cómo y cuánto producir es definido mayoritariamente en función del valor de cambio. En cambio, en el tipo subsistencia las decisiones no son totalmente orientadas por el mercado, ya que parte importante se relaciona con los requerimientos alimentarios de la familia. Así, se observa un alto uso del trabajo familiar, con contrataciones sólo cuando se supera la disponibilidad de trabajo familiar; en contraposición al tipo excedentario, donde sólo un 38% del trabajo es aportado por la familia. Respecto al capital, se observan grandes diferencias entre los dos casos, lo que refuerza la idea de que la estrategia productiva es un reflejo de una condición de dotación de factores dada, más que la consecuencia de una racionalidad económica específica de la familia campesina.