The effects of bilingual language proficiency on recall accuracy and semantic clustering in free recall output: evidence for shared semantic associations across languages.

Two experiments investigated how well bilinguals utilise long-standing semantic associations to encode and retrieve semantic clusters in verbal episodic memory. In Experiment 1, Spanish-English bilinguals (N = 128) studied and recalled word and picture sets. Word recall was equivalent in L1 and L2, picture recall was better in L1 than in L2, and the picture superiority effect was stronger in L1 than in L2. Semantic clustering in word and picture recall was equivalent in L1 and L2. In Experiment 2, Spanish-English bilinguals (N = 128) and English-speaking monolinguals (N = 128) studied and recalled word sequences that contained semantically related pairs. Data were analyzed using a multinomial processing tree approach, the pair-clustering model. Cluster formation was more likely for semantically organised than for randomly ordered word sequences. Probabilities of cluster formation, cluster retrieval, and retrieval of unclustered items did not differ across languages or language groups. Language proficiency has little if any impact on the utilisation of long-standing semantic associations, which are language-general.

δ-Aminolevulinic acid dehydratase single nucleotide polymorphism 2 (ALAD2) and peptide transporter 2*2 haplotype (hPEPT2*2) differently influence neurobehavior in low-level lead exposed children.

Delta-aminolevulinic acid dehydratase single nucleotide polymorphism 2 (ALAD2) and peptide transporter haplotype 2*2 (hPEPT2*2) through different pathways can increase brain levels of delta-aminolevulinic acid and are associated with higher blood lead burden in young children. Past child and adult findings regarding ALAD2 and neurobehavior have been inconsistent, and the possible association of hPEPT2*2 and neurobehavior has not yet been examined. Mean blood lead level (BLL), genotype, and neurobehavioral function (fine motor dexterity, working memory, visual attention and short-term memory) were assessed in 206 males and 215 females ages 5.1-11.8years. Ninety-six percent of children had BLLs<5.0µg/dl. After adjusting for covariates (sex, age and mother's level of education) and sibling exclusion (N=252), generalized linear mixed model analyses showed opposite effects for the ALAD2 and hPEPT2*2 genetic variants. Significant effects for ALAD2 were observed only as interactions with BLL and the results suggested that ALAD2 was neuroprotective. As BLL increased, ALAD2 was associated with enhanced visual attention and enhanced working memory (fewer commission errors). Independent of BLL, hPEPT2*2 predicted poorer motor dexterity and poorer working memory (more commission errors). BLL alone predicted poorer working memory from increased omission errors. The findings provided further substantiation that (independent of the genetic variants examined) lowest-level lead exposure disrupted early neurobehavioral function, and suggested that common genetic variants alter the neurotoxic potential of low-level lead. ALAD2 and hPEPT2*2 may be valuable markers of risk, and indicate novel mechanisms of lead-induced neurotoxicity. Longitudinal studies are needed to examine long-term influences of these genetic variants on neurobehavior.

Sociocultural issues in african american and Hispanic minorities seeking care for attention-deficit/hyperactivity disorder.

OBJECTIVE: To review the sociocultural factors that may affect the diagnosis and management of attention-deficit/hyperactivity disorder (ADHD) in African American and Hispanic minorities seen in the primary care setting in the United States. DATA SOURCES: Searches on MEDLINE and PubMed were conducted in April and September 2012 on ADHD and its related problems and disabilities. A general search was conducted using the terms (attention deficit hyperactivity disorder OR attention deficit/hyperactivity disorder OR ADHD OR AD/HD) AND (ethnicity OR cultural OR culture). Issues of particular relevance to racial and ethnic minorities utilizing health care services were researched using the string (black OR African OR Hispanic OR Latino OR minority OR racial) combined with terms relating to access, insurance, comorbidity, high-risk behavior, treatment compliance, and nonpharmacologic modalities. Searches were limited to English-language citations, and no date parameters were used. References identified as pertinent to this review were selected for citation. STUDY SELECTION/DATA EXTRACTION: Information revealing contrasts between minorities and the US non-Hispanic white population was organized in distinct categories, such as access to medical care and insurance, cultural attitudes, and the effects of stigmatization. The authors also provide perspectives for the primary care physician from their own clinical experience. DATA SYNTHESIS: Rates of diagnosis of in the United States are higher for non-Hispanic whites than for minorities, yet true prevalence is probably similar across racial-ethnic groups. When the stigma of mental illness is added to the challenges faced by racial/ethnic minorities or immigrant status, patients may be especially sensitive. Underuse of clinical services may reflect economic limitations on access to care, cultural attitudes toward mental illness, and the effects of real or perceived prejudice and stigmatization. CONCLUSIONS: Primary care clinicians in the United States should seek to become more aware of cultural factors that could interfere with the recognition and management of ADHD.

Bilingual recognition memory: stronger performance but weaker levels-of-processing effects in the less fluent language.

The effects of bilingual proficiency on recognition memory were examined in an experiment with Spanish-English bilinguals. Participants learned lists of words in English and Spanish under shallow- and deep-encoding conditions. Overall, hit rates were higher, discrimination greater, and response times shorter in the nondominant language, consistent with effects previously observed for lower frequency words. Levels-of-processing effects in hit rates, discrimination, and response time were stronger in the dominant language. Specifically, with shallow encoding, the advantage for the nondominant language was larger than with deep encoding. The results support the idea that memory performance in the nondominant language is impacted by both the greater demand for cognitive resources and the lower familiarity of the words.

δ-Aminolevulinic acid dehydratase single nucleotide polymorphism 2 and peptide transporter 2*2 haplotype may differentially mediate lead exposure in male children.

Child low-level lead (Pb) exposure is an unresolved public health problem and an unaddressed child health disparity. Particularly in cases of low-level exposure, source removal can be impossible to accomplish, and the only practical strategy for reducing risk may be primary prevention. Genetic biomarkers of increased neurotoxic risk could help to identify small subgroups of children for early intervention. Previous studies have suggested that, by way of a distinct mechanism, δ-aminolevulinic acid dehydratase single nucleotide polymorphism 2 (ALAD(2)) and/or peptide transporter 2*2 haplotype (hPEPT2*2) increase Pb blood burden in children. Studies have not yet examined whether sex mediates the effects of genotype on blood Pb burden. Also, previous studies have not included blood iron (Fe) level in their analyses. Blood and cheek cell samples were obtained from 306 minority children, ages 5.1 to 12.9 years. (208)Pb and (56)Fe levels were determined with inductively coupled plasma-mass spectrometry. General linear model analyses were used to examine differences in Pb blood burden by genotype and sex while controlling for blood Fe level. The sample geometric mean Pb level was 2.75 µg/dl. Pb blood burden was differentially higher in ALAD(2) heterozygous boys and hPEPT2*2 homozygous boys. These results suggest that the effect of ALAD(2) and hPEPT2*2 on Pb blood burden may be sexually dimorphic. ALAD(2) and hPEPT2*2 may be novel biomarkers of health and mental health risks in male children exposed to low levels of Pb.

Polymorphisms of delta-aminolevulinic acid dehydratase (ALAD) and peptide transporter 2 (PEPT2) genes in children with low-level lead exposure.

Low-level lead exposure during early childhood has long been associated with altered neurocognitive development and diminished cognitive functions. Over nine thousand U.S. industrial facilities annually emit significant amounts of lead, creating exposure risk particularly for minority children. The mechanisms by which low-level lead exerts neurotoxic effects are poorly understood. Once absorbed, the only intervention is source removal, thus primary prevention is key. Genetic biomarkers could provide an efficient means of identifying children at greatest risk. Common functional variants of genes that alter lead's neurotoxic potential have been identified and include delta-aminolevulinic acid dehydratase (ALAD(2)) and peptide transporter 2 (PEPT2*2). These polymorphisms have not been examined previously in Hispanic minority samples, or with regard to lowest level lead exposure. In 116 children of Mexican-American/Hispanic descent residing in zip codes previously designated as "high risk" for lead exposure (mean age=8.1, S.D.=1.9), blood lead level was measured at three time points over a 3-month period and averaged. DNA extraction was completed using buccal swab samples. The frequencies of the ALAD(2) and PEPT2*2 polymorphisms observed in this sample closely approximated those previously reported for Anglo, European and Asian samples. As compared to children heterozygous for the PEPT2*2 polymorphism, and without the PEPT2*2 polymorphism, the geometric mean blood lead level of children homozygous for the PEPT2*2 polymorphism was significantly higher. In contrast to past studies, mean blood lead level of children heterozygous and homozygous for the ALAD2 polymorphism in this sample did not differ from that of children without the ALAD2 polymorphism. Higher blood lead burden in children with the PEPT2*2 mutation may suggest that this common genetic variant is a biomarker of increased vulnerability to the neurotoxic effects of lowest level lead exposure.

Micosis superficiales en neurofibromatosis

Se investigo la asociación de micosis superficiales en Neurofibromatosis (NF) y se comparó su incidencia con la de un grupo control encontrándose que cerca de las terceras partes de los casos presentaron micosis superficiales del tipo tinea pedis, onicomicosis y pitriases versicolor. Dado estos hallazgos, especulamos que la causa que determina las micosis superficiales en NF pueda esrar relacionada a la quefacilita el desarrollo de tumores no neurales en estos pacientes y ambos a su vez alguna disfunción inmunológica

Reacciones cutáneas de hipersensibilidad tardía en pacientes con neurofibromatosis / Delayeel hypersensitivity cutaneous reaction in patients with neurofibromatosis

Se utilizó un multitest del Meireux Institute (Lyon, Francia) para la evaluación de la inmunidad celular en 19 pacientes con diagnóstico de neurofibromatosis del Sevicio de Genética de la Clínica Infantil Dr. Robert Reid Cabral. Se obtuvieron un total de 17 pacientes con reacciones positivas en las pruebas aplicadas, lo que corresponde a un 89.5% de los mismos, 12 fueron hipoérgicos, o sea, 63.2% y cinco (26.3%) tuvieron una respuesta normal; dos pacientes no respondieron, lo que corresponde a 10.5% de los casos