Future doctors and brain death: what is the prognosis?

OBJECTIVE: To evaluate the knowledge and the opinion of medical students at the Pontifical Catholic University of São Paulo related to the general aspects of donation, organ and tissue procurement, and basic concepts of brain death (BD). MATERIALS AND METHODS: Questionnaires of 24 items were distributed among all students related to the concept and diagnosis of BD, personal aspects of tissue and organ donation, and general question concerning organ donation. The answers classified students as good versus bad experts of the concept and the diagnosis of BD. RESULTS: Of a total of 580 students, 361 (62.24%) answered the questionnaire. Although the concept of BD was known to 70%, only 35% had a good knowledge of the diagnosis. One percent of the students were opposed to the organ donation and 76% of them were donors. Approximately 90% would authorize organ retrieval from their family members but 27% had never discussed organ donation with their families. Most students were interested in the general aspects of donation and organ procurement (88.36%). CONCLUSION: The majority of the students know the concept of BD. General aspects regarding tissue and organ donation and diagnosis of BD might be improved with the continued education on the subject.

Trypanosoma cruzi: detection of a circulating antigen in urine of chagasic patients sharing common epitopes with an immunodominant repetitive antigen.

A monospecific antiserum raised to a Trypanosoma cruzi recombinant antigen, with tandem repeat of 68 amino acids, was used to screen urine samples of chagasic and nonchagasic patients. The antiserum detected a specific 150-160 kDa antigen in urine of 60% of chronic chagasic patients, but not in urine samples from nonchagasic patients and healthy control individuals. The reactivity to 150-160 kDa urinary antigen could be abolished by adsorption with the recombinant repetitive antigen. These results suggest that 150-160 kDa urinary antigen is a T. cruzi-derived antigen and specific for Chagas' disease.

BTG1, a member of a new family of antiproliferative genes.

The BTG1 gene locus has been shown to be involved in a t(8;12)(q24;q22) chromosomal translocation in a case of B-cell chronic lymphocytic leukemia. We report here the cloning and sequencing of the human BTG1 cDNA and establish the genomic organization of this gene. The full-length cDNA isolated from a lymphoblastoid cell line contains an open reading frame of 171 amino acids. BTG1 expression is maximal in the G0/G1 phases of the cell cycle and is down-regulated when cells progress throughout G1. Furthermore, transfection experiments of NIH3T3 cells indicate that BTG1 negatively regulates cell proliferation. The BTG1 open reading frame is 60% homologous to PC3, an immediate early gene induced by nerve growth factor in rat PC12 cells. Sequence and Northern blot analyses indicate that BTG1 and PC3 are not cognate genes. We then postulate that these two genes are the first members of a new family of antiproliferative genes.

Trypanosoma cruzi: cloning and expression of an antigen recognized by acute and chronic human chagasic sera.

Here we describe the characterization of a Trypanosoma cruzi DNA sequence (clone A13) that codes for a polypeptide recognized by IgM and IgG antibodies from sera of acute and congenital chagasic patients. Antibodies to A13 antigen are also detected in the sera of chronic patients with different clinical forms of Chagas' disease, but not in sera of patients with leishmaniasis or other parasitic diseases. The antigenic determinants encoded by clone A13 are found in amastigotes and trypomastigotes of several T. cruzi strains, but not in the noninfective epimastigotes. The DNA sequence of the recombinant clone reveals one open reading frame encoding 251 amino acids without tandemly repeated sequences. Our data suggest that the A13 antigen may be useful for the development of serodiagnostic procedures.

Expression in Escherichia coli of a dominant immunogen of Trypanosoma cruzi recognized by human chagasic sera.

A genomic clone expressing a Trypanosoma cruzi antigen in Escherichia coli was identified using human chagasic sera. Chagasic antibodies affinity purified on extracts of this clone recognized a high-molecular-weight protein expressed in all developmental stages of the parasite life cycle, as well as in various T. cruzi strains. The antigen is associated with the cytoskeleton of the parasite and localizes along the attachment region between the flagellum and the cell body. Antibodies to the recombinant antigen were detected in the sera of 115 chagasic patients from different endemic regions, but not in sera of patients with leishmaniasis, T. rangeli infection, or other parasitic diseases. Our data suggest that the presence of antibodies to this antigen may be specifically associated with Chagas' disease.

Analysis of the specificity of human antibodies to antigens of Leishmania braziliensis braziliensis.

The antigenicity of promastigotes of Leishmania braziliensis braziliensis (L. b. braziliensis) treated with 1% sodium desoxycholate in 10 mM Tris-Hcl pH 8.2 was analysed by immunoblot using as probes sera from American cutaneous leishmaniasis (ACL), American visceral leishmaniasis (AVL), schistosomiasis, malaria and Chagas' disease. The ACL sera reacted constantly with a 60 kD band. No reactivity to this protein was observed with sera from the other diseases above mentioned indicating that the 60 kD protein may be used in serodiagnosis for ACL.

Myenteric plexus in a freshwater teleost intestine. I. Quantitative study of nerve cells.

The number of nerve cells in the myenteric plexus of a freshwater teleost (Pimelodus maculatus) was obtained with the aid of statistical methods. 1. The density of neurons/cm2 was the following: 91,142 in the duodenum; 93,133 in the ileum and 82,857 in the rectum. These 3 portions have not showed statistically significant differences. 2. The mean surface area of the intestine being 48 cm2, the total number of neurons in myenteric plexus of the duodenum, ileum and rectum was calculated to be 4,274,112.

Self-instruction in anatomy for medical students.

The authors describe the results of the use of a self-instructional material (study guide-book) during two Anatomy courses (cardio-respiratory and locomotor) given to first year medical students of São Paulo University. The rate of approval was considered very good in both courses.