During recent years, several Leishmania infantum genes have been cloned and characterized. Here, we have summarized the available information on the gene organization and expression in this protozoan parasite. From a comparative analysis, the following outstanding features were found to be common to most of the genes characterized: tandemly organized genes with conserved coding regions and divergent untranslated regions, polycistronic transcription and post-transcriptional regulation of gene expression. The analysis of chromosomes of L. infantum by pulsed-field electrophoresis showed the existence of both size and number polymorphisms such that each strain has a distinctive molecular karyotype. Despite this variability, highly conserved physical linkage groups exists among different strains of L. infantum and even among Old World Leishmania species. Gene mapping on the L. infantum molecular karyotype evidenced a bias in chromosomal distribution of, at least, the evolutionary conserved genes.

Animals↗

PubMedDate not supplied

Thromboembolism in chronic Chagas' heart disease.

Thromboembolic episodes are particularly important in chronic Chagas' heart disease. Systemic and pulmonary embolic phenomena are important complications of the disease. Prophylaxis of the thromboembolic phenomena with anticoagulant therapy should be considered in several clinical forms of the disease. Further studies will have to address the stratification risk issue.

Chagas Cardiomyopathy↗

PubMedDate not supplied

[Chronic diarrhea as a clinical expression of common variable hypogammaglobulinemia: apropos of 3 cases].

Sixty per cent of the patients with immuno-compromise of the humoral compartment may show chronic diarrhoea, specially seen in the common variable hypogammaglobulinemia (CVH). We presented 3 cases of late-onset CVH who referred chronic diarrhoea as the main symptom. The immunodiagnosis revealed undetectable or subnormal immunoglobulins levels (G, M, A), preserved total haemolytic complement and a negative autoimmune screening. The cell compartment analysis showed increased number of suppressor T lymphocytes (CD8) plus hyporesponsiveness of the total peripheral lymphocytes to polyclonal mitogens such PHA. The clinical approach of the CVH patients should be performed by a multispecialized team including the clinical immunologist and the gastrointestinal and infectious diseases specialists.

Adult↗

PubMedDate not supplied

[Seroprevalence of delta infection in a group of patients with HBsAg positive in the city of Maracaibo].

In order to establish a preliminary information about the penetration of delta infection in our population, 40 HBsAg positive sera were tested for antidelta. 20 were asymptomatic patients and 20 were symptomatics. In the group of asymptomatic patients 3 belong to a high risk population: 1 homosexual, 1 dialysis patient, 1 nurse of dialysis unit. None of the patients of this group were positive for antidelta. In the group of symptomatics one was positive for antidelta. It's represents a seroprevalence of 5%. This patient was an indian who lives in the city but was born in Perijá where severe epidemics have been reported. These results support that the infection seems to be restricted to this indigenous group but the spread must be considered because the patient was living in the city. In addition, the use of antidelta as the unique serologic marker should undervalue the real prevalence of infection in the cases of acute hepatitis, which represent the majority of symptomatics patients. In consequence the paper of delta agent must be considered in the genesis of hepatitis in our population as well as its further epidemiologic course.

Adolescent↗

PubMedDate not supplied

[Influence of antiadrenergic drugs on the development of tolerance to the analgesic effect of morphine (author's transl)].

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Animals↗