Sex difference in hemispheric lateralization

Study of sexual differences for the hemispheric prevalence on visual verbal stimuli using a microcomputer-based tachistoscope technic. Seventeen right-handed individuals, 10 males and 7 females (mean age 32 years old), without neurological or visual abnormalities were studied. The subjects performed a verbal trigram tachistoscope test, using a IBM PC microcomputer compatible. The trigram consists of 80 consonant-vowel-consonant pairs of stimuli presented randomly to right and left visual fields. The evaluation was made through two conditions: T1 and T2. In T1 Experiment stimuli exposition time was 260 ms, and in T2 Experiment the stimuli exposition time was 160 ms. In Tl Experiment 80% of females showed a Right Hemispherical Preference while 100% of males showed a Left Hemispherical Preference. In T2 Experiment, both sexes showed Left Hemispheric Preference. A close relationship between sexual difference and hemispheric preference was found. We point out the importance of stimuli exposition time in determination of sexual differences in lateral hemispherical asymmetry.Estudo de 17 indivíduos destros, 10 mulheres e 7 homens, sem anormalidades neurológicas ou sivuais, em relação às diferenças sexuais no processamento hemisférico de estímulos verbais. Os indivíduos foram avaliados por provas taquistoscópicas verbais, utilizando microcomputador compatível ao IBM-PC. As provas constituíram-se de 80 pares de estímulos apresentados simultaneamente ao campo visual direito e esquerdo. A avaliação foi realizada em duas situações distintas, que diferiram entre si pelo tempo de exposição dos estímulos. No Experimento Tl, em que o tempo de exposição foi 260 ms, 80% das mulheres apresentaram Preferência Hemisférica Direita, enquanto 100% dos casos masculinos apresentaram Preferência Hemisférica Esquerda. No Experimento T2 (tempo de exposição 160 ms) houve predomínio da Preferência Hemisférica Esquerda em ambos os sexos. Por este estudo observamos a importância da determinação do tempo de exposição dos estímulos na verificação das diferenças sexuais no processamento da linguagem.Escola Paulista de MedicinaUNIFESP, EPMSciEL

Functional brain asymmetry in motor aphasia during auditory stimulation: report of two cases

This study concerns about brain electrical activity during auditory stimulation in 2 aphasic patients, one with classical (left hemisphere lesion) and another with cross aphasia (right hemisphere lesion). Both cases were submitted to dichotic listening test (consonat-vowel-consonant task) and music audition (gregorian chant), during brain mapping examination. We found, in both cases, a great proportion in delta frequency and power in non-lesional hemisphere during dichotic and musical stimulation. Besides, increasing in frequency of alpha activity was observed only in the non-lesional hemisphere restricted to temporal lobe region. Such findings suggest an interesting field of research about measurements of neurophysiologies correlates of auditory stimulation and brain electrical activity in aphasia.Este estudo diz respeito à atividade elétrica cerebral durante estimulação auditiva em dois pacientes afásicos, um com afasia clássica (lesão no hemisfério esquerdo) e outro com afasia cruzada (lesão no hemisfério direito). Ambos foram submetidos ao teste de estimulação auditiva dicótica (consoante-vogal-consoante) e de audição musical (canto gregoriano) durante mapeamento eletrencefalográfico cerebral. Encontramos, em ambos, grande proporção da frequência delta e potência no hemisfério não lesado, durante a estimulação dicótica e musical. Além disso, foi observado aumento na frequência de atividade alfa somente no hemisfério não lesado, restrito à região do lobo temporal. Esses achados sugerem um interessante campo de pesquisa acerca da medida de correlatos neurofisiológicos de estimulação auditiva e de atividade elétrica cerebral na afasia.Escola Paulista de Medicina Setor de Investigação e Tratamento das EpilepsiasUNIFESP, EPM, Setor de Investigação e Tratamento das EpilepsiasSciEL

Cardiovascular Response to Beta-Adrenergic Blockade or Activation in 23 Inbred Mouse Strains

We report the characterisation of 27 cardiovascular-related traits in 23 inbred mouse strains. Mice were phenotyped either in response to chronic administration of a single dose of the β-adrenergic receptor blocker atenolol or under a low and a high dose of the β-agonist isoproterenol and compared to baseline condition. The robustness of our data is supported by high trait heritabilities (typically H2>0.7) and significant correlations of trait values measured in baseline condition with independent multistrain datasets of the Mouse Phenome Database. We then focused on the drug-, dose-, and strain-specific responses to β-stimulation and β-blockade of a selection of traits including heart rate, systolic blood pressure, cardiac weight indices, ECG parameters and body weight. Because of the wealth of data accumulated, we applied integrative analyses such as comprehensive bi-clustering to investigate the structure of the response across the different phenotypes, strains and experimental conditions. Information extracted from these analyses is discussed in terms of novelty and biological implications. For example, we observe that traits related to ventricular weight in most strains respond only to the high dose of isoproterenol, while heart rate and atrial weight are already affected by the low dose. Finally, we observe little concordance between strain similarity based on the phenotypes and genotypic relatedness computed from genomic SNP profiles. This indicates that cardiovascular phenotypes are unlikely to segregate according to global phylogeny, but rather be governed by smaller, local differences in the genetic architecture of the various strains

The impact of diabetes on the pathogenesis of sepsis

Diabetes is associated with an increased susceptibility to infection and sepsis. Conflicting data exist on whether the mortality of patients with sepsis is influenced by the presence of diabetes, fuelling the ongoing debate on the benefit of tight glucose regulation in patients with sepsis. The main reason for which diabetes predisposes to infection appears to be abnormalities of the host response, particularly in neutrophil chemotaxis, adhesion and intracellular killing, defects that have been attributed to the effect of hyperglycaemia. There is also evidence for defects in humoral immunity, and this may play a larger role than previously recognised. We review the literature on the immune response in diabetes and its potential contribution to the pathogenesis of sepsis. In addition, the effect of diabetes treatment on the immune response is discussed, with specific reference to insulin, metformin, sulphonylureas and thiazolidinediones