[Identification of caprine arthritis encephalitis virus using histopathological, immunohistochemica, and ultrastructural examination of tissues from seropositive goats in Mexico]. / Identificación del virus de la artritis encefalitis caprina mediante el estudio histopatológico, inmunohistoquímico y ultraestructural, en tejidos de cabras seropositivas en México.

This study demonstrated the presence of viral particles suggestive of arthritis-encephalitis virus through the clinic, serologic, pathologic, immunohistochemic and ultrastructural studies in dairy goats. In the postmortem studies the tissues used were: synovial membrane, lungs and mammary gland from goats with clinical signs characteristic of the disease and positive for serum antibodies to the virus.

[Psychosocial and familial variables associated with teenage pregnancy]. / Variables psicosociales y familiares asociadas con el embarazo de adolescentes.

Preventive measures for teenage pregnancy (TP), would decrease infant mortality, early undernutrition and statal social expenditure. The cost of programs for TP would decrease with a sensitive risk indicator. We searched some pysoshocial and familial parameters, useful to built up this indicator. Self esteem (Piers-Harris test), intrafamilial relationship (Familial Apgar of Magdaleno) and the use of break time were studied in 60 pregnant teenagers (PT), 60 non pregnant teenagers at a low risk of pregnancy (LRP) and 60 non pregnant teenagers at a high risk of pregnancy (HRP). PT and HRP showed lower self esteem than LRP (88.3, 70.0 Y 41.6% respectively, under 7 points) lower familial Apgar (61.6, 50 y 8.3% under score 6) and lower the quality of use of break time (66.7, 74.1 y 31.7% respectively with regular or deficient quality). The self esteem, intrafamilial relationship hand use of break time were associated to early pregnancy and high risk of pregnancy. These parameters are important to built up a sensitive risk indicator of early pregnancy in order to decrease the prevalence of this serious problem.

[Induction of polyvalent immunity against Actinobacillus pleuropneumoniae in an experimental rat model]. / Inducción de inmunidad polivalente contra Actinobacillus pleuropneumoniae en un modelo experimental en la rata.

Using an experimental model of passive immunity in the rat, the immunizing effect of live cells of Actinobacillus pleuropneumoniae serotypes 1, 3, 5, 7, 9 and 12 was tested against a challenge with serotype 1. It was observed that serotypes 5, 7 and 9 induced polyvalent immunity. Additionally, agglutinating antibodies to the homologous and heterologous serotype were titrated in the sera of immunized mothers; the results indicated that groups immunized with serotypes 5, 7 and 9 had higher titers against serotype 1.

A novel experimental model for the study and evaluation of experimental vaccines to Actinobacillus pleuropneumoniae.

A novel experimental model to study immune protection to Actinobacillus pleuropneumoniae in the rat is described. One-week-old rats born from immunized mothers were challenged intraperitoneally with a suspension of A. pleuropneumoniae serotype 1 and mortality recorded up to 48 h postinfection. Immunization with inactivated whole cells (IWC) or a whole cell extract (WCE) from A. pleuropneumoniae serotype 1 resulted in protection against an homologous challenge, particularly in the case of WCE where protection was observed at the highest challenge dose of approximately 1000 50% lethal doses.

[Early pregnancy risk: development and validation of a predictive instrument]. / Riesgo de embarazo temprano: construcción y validación de un instrumento predictor.

An early pregnancy risk scale, with scores ranging from 11 to 66 points from lower to higher risk, was constructed using variables associated with teenager's pregnancy. This scale was applied to 3000 female teenagers, coming from Metropolitan Santiago public schools. The sample was divided in three risk groups: group A (high risk) with scores equal or over 35 points, group B (low risk) with scores equal or below 20 points and group B (intermediate risk) with scores between 20.1 and 34.9 points. These girls were followed during 2 years. During this period, 84 girls became pregnant, 24 of 184 (13%) in group A, 60 of 2332 (2.6%) in group C and none of 307 in group B. There were 104 school desertions in group A and 37 in group B. To study associations and analyze risk, the sample was divided in two risk groups: high, with scores over 27 and low, with scores below 27. There was a high association between pregnancy risk score and the occurrence of pregnancy (RR 5.25 p < 0.0001) and school desertion (RR 3.32 p < 0.0001). Pregnancy was predicted with a 78% sensitivity and 55.6% specificity. School desertion was predicted with a 74% sensitivity and 56% specificity. The importance variable weighing using multiple regression models, to improve the predictor's sensitivity and specificity, is discussed.