Psychic suffering and depression in black children and adolescents: systematic review and meta-analysis

Depression is a common disorder in the population, but some people are more vulnerable to this condition. Groups at higher risk of developing psychic suffering include black children and adolescents living in vulnerable socioeconomic conditions. This study aimed to analyze race and life conditions as determinants of depression in children and adolescents. This was a systematic review with meta-analysis. The study sources were MEDLINE Ovid, Web of Science, Latin American and Caribbean Health Science Information database, Science Citation Index-Expanded, PubMed, EMBASE, and Scopus. The following keywords were used: Child, Adolescent, Stress, Psychological, Depression, and African Continental Ancestry Group, using the logical operators AND and OR. The general criteria were observational studies published in the last 20 years. Language was not restricted to avoid possible bias in the selection of articles. Studies with a high risk of bias were excluded. General analysis was conducted with RStudio 3.0 software using odds ratio analysis with a 95% confidence interval and 0.05 significance level. We firstly found 654 studies, of which 18 met the criteria and were included in this review. Race and life conditions were determinants of depression in children and adolescents, with a negative impact for the black population.

Screening for fragile X syndrome among Brazilian mentally retarded male patients using PCR from buccal cell DNA

Fragile X syndrome is one of the most frequent causes of mental retardation. Since the phenotype in this syndrome is quite variable, clinical diagnosis is not easy and molecular laboratory diagnosis is necessary. Usually DNA from blood cells is used in molecular tests to detect the fragile X mutation which is characterized by an unstable expansion of a CGG repeat in the fragile X mental retardation gene (FMR1). In the present study, blood and buccal cells of 53 mentally retarded patients were molecularly analyzed for FMR1 mutation by PCR. Our data revealed that DNA extraction from buccal cells is a useful noninvasive alternative in the screening of the FMR1 mutation among mentally retarded males.

Colocalization of coilin and nucleolar proteins in Cajal body-like structures of micronucleated PtK2 cells

Cajal bodies (CB) are ubiquitous nuclear structures involved in the biogenesis of small nuclear ribonucleoproteins and show narrow association with the nucleolus. To identify possible relationships between CB and the nucleolus, the localization of coilin, a marker of CB, and of a set of nucleolar proteins was investigated in cultured PtK2 cells undergoing micronucleation. Nocodazol-induced micronucleated cells were examined by double indirect immunofluorescence with antibodies against coilin, fibrillarin, NOR-90/hUBF, RNA polymerase I, PM/Scl, and To/Th. Cells were imaged on a BioRad 1024-UV confocal system attached to a Zeiss Axiovert 100 microscope. Since PtK2 cells possess only one nucleolus organizer region, micronucleated cells presented only one or two micronuclei containing nucleolus. By confocal microscopy we showed that in most micronuclei lacking a typical nucleolus a variable number of round structures were stained by antibodies against fibrillarin, NOR-90/hUBF protein, and coilin. These bodies were regarded as CB-like structures and were not stained by anti-PM/Scl and anti-To/Th antibodies. Anti-RNA polymerase I antibodies also reacted with CB-like structures in some micronuclei lacking nucleolus. The demonstration that a set of proteins involved in RNA/RNP biogenesis, namely coilin, fibrillarin, NOR-90/hUBF, and RNA polymerase I gather in CB-like structures present in nucleoli-devoid micronuclei may contribute to shed some light into the understanding of CB function.