Molecular and epidemiological investigations of cryptosporidiosis in Cuban children.

Molecular and epidemiological studies of Cryptosporidium infections amongst 28 Cuban children (aged 2-8 years) with diarrhoea are described. As few of the younger infected children but most of the older infected children had been breastfed, short-term protection from maternal antibodies passed to infants during breastfeeding may result in a lack of cryptosporidial infection in infancy. This protection of breastfeeding children may, however, result in such children developing less anti-Cryptosporidium immunity of their own (than their bottle-fed counterparts), so that, by school age, the children who had been breastfed are those most likely to be found infected. In the present study, in contrast with the observations made during a previous study of cryptosporidiosis in Cuban children, vomiting was rare (7%) whereas abdominal pain was common (57%). These differences in expression of symptoms between studies may be age-related. As seen in other studies from similar countries, including those of the Caribbean and Latin America, C. hominis was found to predominate, the results of the successful molecular analyses revealing 10 C. hominis infections but no C. parvum. Subgenotyping (at the gp60 locus) indicated that the C. hominis infections included a wide range of subtypes, with isolates from three subtype families (Ia, Ib and Id) being detected.

Giardia infections in Cuban children: the genotypes circulating in a rural population.

Stool samples containing Giardia duodenalis cysts were collected from 95 primary-school children in central Cuba, and preserved by storing at -20 degrees C in 70% ethanol. Clinical data were collected for each child. Although 57% of the children were asymptomatic, the remaining 43% each reported between one and three symptoms. Following cyst quantification and isolation, molecular analyses were attempted on all cyst isolates, with the focus on the parasite's beta-giardin and glutamate-dehydrogenase (gdh) genes. Unfortunately, the cyst-preservation procedure appeared to have a deleterious effect on the cysts, since genotyping data could only be obtained for 20 of the 95 isolates. These data indicated, however, an approximately equal distribution between assemblage A (nine isolates) and assemblage B (11 isolates). Children found to be excreting relatively large numbers of cysts were more likely to be symptomatic than children who were excreting fewer cysts, and children with Giardia isolates from assemblage B were more likely to have symptomatic infections than children with isolates from assemblage A. Although considerable sequence variability was seen in the assemblage-B isolates, the assemblage-A isolates were relatively genetically homogeneous. This is the first publication from the Caribbean in which the Giardia genotypes circulating within the population have been identified, the first from the Americas providing information on associations between clinical presentation and the assemblage of the infecting Giardia, and the first to indicate that levels of cyst excretion may have clinical significance.

Delivery of immunoprophylactics in transgenic plants: current status.

The search for economic alternatives for the production of recombinant immunoprophylactics has resulted in the concept of generating them in plants at relatively low cost. Two basic strategies are employed: the expression of recombinant antigens or antibodies in transgenic plants, or the presentation of small antigen epitopes on the surface of genetically modified plant viruses. Both approaches have resulted in the production of biologically active immunoprophylactics that have been shown in animal studies to protect from the development of disease symptoms. An especially interesting feature of producing vaccines in edible plant parts is the potential to use the transgenic plant as a vehicle for oral delivery. Substantial progress has been made over the past few years, and the first clinical trials have demonstrated the potential of this new technology. Future challenges are to express the immunoprophylactics at controlled, high concentrations in plants that could be grown locally where they are needed, and to develop easy and standardised administration procedures.

Fracturas de las raíces intraalveolares: Estudio radiográfico e histológico de 50 casos

La presente investigación es un análisis clínico y radiográfico de 50 fracturas intraalveolares de la raiz y una evaluación histológica de 12 de estos dientes. Se presenta una clasificación sobre los resultados de curación. Esta se estableció en 27 dientes (54 porciento). Las fracturas ocurrieron más frecuentemente en el tercio medio de la raíz, pero la situación, sea en el tercio apical, medio o gingival, no influencia en el resultado. La dislocación del fragmento coronal influyó negativamente en el significado del pronóstico, mientras que la reducción óptima de los fragmentos aumentó significativamente la oportunidadpara un pronóstico mejor. La fijación pareció dar un mejor pronóstico comparada con la no fijación(AU)