[Estimations of the prevalence of attention deficit hyperactivity disorder in Marabino children]. / Estimaciones de la prevalencia del trastorno por déficit de atención-hiperactividad en niños marabinos.

AIMS: This study reports the findings of research aimed at determining the rate of prevalence of attention deficit hyperactivity disorder (ADHD) in children of school age. SUBJECTS AND METHOD: The epidemiological study was conducted using a community sample extracted by means of multi stage stratified sampling according to socio economic level and schooling and consisted in 1,141 children of both sexes of school age from the city of Maracaibo. The revised Conners scales were used to collect data. RESULTS: The estimated prevalence of ADHD was 7.19% and we also obtained 0.35% for the hyperactive type, 1.14% for the disattentional subtype, and 5.70% for the combined type. Contrary to what was expected, prevalence was higher for females. It was found that 7.45% of the general sample scored higher on the academic problems scales, whereas for the sample identified as having ADHD, academic problems were 50% and the comorbidity between ADHD and academic problems was confirmed. CONCLUSIONS: The estimates for prevalence found in this study are consistent with those reported in the literature, which suggests that ADHD is a valid diagnosis for Marabino children.

Studies of cultured human T lymphocytes. II. Initiation of paired T- and B-cell lines from healthy donors.

We report the sustained cultivation of both B- and T-lymphoblastoid cell lines from randomly selected healthy donors, and the results of studies defining the frequency with which these cell lines can be established. B-cell lines were initiated using the Epstein-Barr virus. Of 52 attempts, 40 B-cell lines (77% success) were obtained from 24 different donors. T-cell lines were started and propagated in long-term (greater than 100 days) cultures using the T-cell growth factor interleukin-2 (IL-2). Of 55 attempts, 54 (98%) were successful in initiating IL-2-dependent T-cell lines, and these were derived from 28 healthy adults. Likewise, of 45 attempts, 32 (71%) were successful in producing paired lines in which both the B-cell line and T-cell line were cultivated from a single blood collection (N = 22 donors). Phenotypic profiles of these lines were defined using multiple marker assays, including rosette formation, surface immunoglobulins, cytochemistry, karyotype, as well as xenoantisera and monoclonal antibodies defining different membrane antigens. This work demonstrates the feasibility of propagating paired human B and T lymphoblastoid lines suitable for many comparative immunobiological studies.