Systolic luminal narrowing and morphologic characteristics of myocardial bridging of the mid-left anterior descending coronary artery by dual-source computed tomography

To identify factors that can affect systolic compression of myocardial bridging (MB) of the mid-left anterior descending (LAD) coronary artery with dual-source computed tomography (DSCT). Patients with mid-LAD MB (n = 198) detected by DSCT were studied. MB was classified as incomplete superficial (IS), complete superficial (CS), and deep (D) type. The depth and length of the mid-LAD MB segment in diastole, luminal reduction of the tunneled LAD segment in systole, and degree of systolic left ventricular (LV) wall thickening were all analyzed. Correlation between the depth, length, degree of systolic LV wall thickening, and luminal narrowing in the systolic phase was evaluated. Eighty-one (40.9%) MB were IS, 37 (18.7%) were CS, and 80 (40.4%) were D type. Significant differences in the degree of luminal narrowing in the systolic phase were found among the three MB types (IS, 19.9 ± 10.1%; CS, 26.9 ± 12.1%; D, 36.6 ± 13.8%; P < 0.0001). The luminal narrowing in the systolic phase correlated with the depth (r = 0.56) and percentage of systolic LV wall thickening (r = 0.44), but was not related to length (r = 0.28). In addition to the degree of LV systolic wall thickening and depth of MB, the types of MB also affect luminal narrowing in the systolic phase.     

Effects of physical exercise on spatial memory and astroglial alterations in the hippocampus of diabetic rats

Type 1 diabetes mellitus (T1DM) is associated with neurocognitive dysfunction and astrogliosis. Physical exercise prevents cognitive impairments and induces important brain modifications. The aim of our study was to investigate the effect of treadmill exercise on spatial memory and astrocytic function in the hippocampus of a T1DM model. Fifty-seven Wistar rats were divided into four groups: trained control (TC) (n = 15), non-trained control (NTC) (n = 13), trained diabetic (TD) (n = 14) and non-trained diabetic (NTD) (n = 15). One month after streptozotocin-induced diabetes, exercise groups were submitted to 5 weeks of physical training, and then, all groups were assessed in the novel object-placement recognition task. Locomotor activity was analyzed in the open field apparatus using Any-maze software. The expression of glial fibrillary acidic protein (GFAP) and S100B in hippocampus and cerebrospinal fluid were measured using ELISA assay, and hippocampal GFAP immunoreactivity was evaluated by means of immunohistochemistry and optical densitometry. The results showed that physical exercise prevents and/or reverts spatial memory impairments observed in NTD animals (P < 0.01). Decreased locomotor activity was observed in both the NTD and TD groups when compared with controls (P < 0.05). ELISA and immunohistochemistry analyzes showed there was a reduction in GFAP levels in the hippocampus of NTD animals, which was not found in TD group. ELISA also showed an increase in S100B levels in the cerebrospinal fluid from the NTD group (P < 0.01) and no such increase was found in the TD group. Our findings indicate that physical exercise prevents and/or reverts the cognitive deficits and astroglial alterations induced by T1DM.     

Williams syndrome hypersociability: a neuropsychological study of the amygdala and prefrontal cortex hypotheses

Individuals with Williams syndrome display indiscriminate approach towards strangers. Neuroimaging studies conducted so far have linked this social profile to structural and/or functional abnormalities in WS amygdala and prefrontal cortex. In this study, the neuropsychological hypotheses of amygdala and prefrontal cortex involvement in WS hypersociability was explored using three behavioral tasks - facial emotional recognition task, a social approach task and a go no/go task. Thus, a group 15 individuals with Williams syndrome was compared to two groups of normal developing individuals - a group of 15 individuals matched for chronological age (CA) and 15 individuals matched for mental age (MA), and sex. Individuals with WS present a specific impairment in recognizing negative facial expressions and do not display impairments in response inhibition when compared with typically developing groups. Although these findings partially support the amygdala contribution to WS hypersociability, we found that general cognitive functioning predicted this performance. Additionally, individuals with WS did not differ from both CA and MA groups in the recognition of angry facial expressions, a finding suggesting that they are actually able to identify stimuli associated with social threat. Overall, the results seem to indicate that this social profile must be understood within a developmental framework.