The COMT Val158Met polymorphism and temporal lobe morphometry in healthy adults

We examined the relationship between COMT Val158Met genotype and temporal lobe volumes, including the caudate as a control region. Thirty-one healthy subjects completed 1.5T brain MRI and genotyping. After controlling for demographics, Val158 allele homozygotes exhibited significantly smaller temporal lobe and hippocampal volumes, with a trend for smaller amygdala volumes.     

Characterization of human immunodeficiency virus (HIV)-infected cells in infiltrates associated with CNS opportunistic infections in patients with HIV clade C infection

Infection with human immunodeficiency virus (HIV) clade C is the most common HIV infection worldwide, yet its impact on the nervous system remains largely unknown. Autopsy studies from regions affected by this virus are scarce, and HIV dementia has only rarely been reported from these countries. Most patients who develop neurologic complications die of opportunistic infections. We thus conducted a neuropathologic study from a single institution in India to characterize the HIV-infected cells in the inflammatory infiltrates in a total of 15 cases (5 patients each who died of either CNS toxoplasmosis, tuberculosis, or cryptococcal meningitis). Nearly, all patients had HIV-infected cells in the brain, although these cells were most abundant in patients with toxoplasma encephalitis. Interestingly, none of the patients had any multinucleated giant cells. HIV-infected cells were found in the parenchyma, perivascular regions, and choroid plexus and found infiltrating the parenchyma from the meninges, suggesting multiple portals of entry into the brain. These findings suggest the possibility that patients, even if successfully treated for an opportunistic inflection, may be at high risk of developing HIV encephalitis and subsequent dementia.     

Neural correlates of promotion and prevention goal activation: an fMRI study using an idiographic approach

Regulatory focus theory [Higgins, E. T. Beyond pleasure and pain. American Psychologist, 52, 1280-1300, 1997] postulates two social-cognitive motivational systems, the promotion and prevention systems, for self-regulation of goal pursuit. However, the neural substrates of promotion and prevention goal activation remain unclear. Drawing on several literatures, we hypothesized that priming promotion versus prevention goals would activate areas in the left versus right prefrontal cortex (PFC), respectively, and that activation in these areas would be correlated with individual differences in chronic regulatory focus. Sixteen participants underwent functional magnetic resonance imaging while engaged in a depth-of-processing task, during which they were exposed incidentally to their own promotion and prevention goals. Task-related cortical activation was consistent with previous studies. At the same time, incidental priming of promotion goals was associated with left orbital PFC activation, and activation in this area was stronger for individuals with a chronic promotion focus. Findings regarding prevention goal priming were not consistent with predictions. The data illustrate the centrality of self-regulation and personal goal pursuit within the multilayered process of social cognition.     

Linear affine transformations between 3-lead (Frank XYZ leads) vectorcardiogram and 12-lead electrocardiogram signals

Background

Recent advances in computer graphics and wireless technologies have renewed interest in vectorcardiogram (VCG) signals that use fewer leads than the conventional 12-lead electrocardiogram (ECG) signals for medical diagnostic applications. However, most cardiologists are accustomed to the 12-lead ECG even though some of the leads are either nearly aligned with or derived from the others and consequently contain redundant information. The ability to transform from orthogonal 3-lead VCG to 12-lead ECG enables the use of fewer leads for signal analysis, computer visualization, and wireless transmission of signals. This can also improve mobility, albeit limited, to the patients.

Materials and Methods

We present a statistical approach to transform 3-lead Frank VCG to 12-lead ECG signals and vice versa, based on Dower's pioneering work on lead tranformation. This approach enables compensation of baseline shifts and other constant biases present in long ECG data streams, so that the resulting statistical transforms can be more consistent and accurate. We compare the performance of the affine transform with that of Dower transform (from 3 to 12 and from 12 to 3) using the data from the PhysioNet PTB database.

Results

The results show that for both myocardial infarction (MI) and healthy control (HC) subjects, the statistical affine transform presented here maps 3-lead VCG to12-lead ECG more accurately than Dower or other lead transformation matrices of the ECG recordings.

Discussion

This investigation also shows the limitations associated with single dipole assumption that underlies Dower's geometric transformation. The results also indicate that lead transformation accuracy can be improved using separate customized transforms to, for example, age or pathologic conditions (here, MI vs HC) than a single statistical or geometric transform. Pertinently, we find that the affine transform coefficients can serve as discriminating features for classification/discrimination of MI patients from HC subjects.     

Optic nerve axonal pathology is related to abnormal visual evoked responses in AIDS

Electrophysiological studies in subjects with HIV/AIDS demonstrate subtle changes in the visual pathway even in the absence of visual symptoms. But the pathological correlate of the electrophysiological abnormalities is largely unknown. This study attempts to correlate pathological changes in the retina and intraorbital portion of optic nerve in four drug naïve patients of AIDS caused by HIV-1 clade C, who had abnormalities in the visual evoked potentials recorded antemortem. Three had no visual complaints and one patient had sudden loss of vision in the right eye. In all four patients, the visual evoked potentials disclosed variable prolongation of P100 latencies. Histologically axonal cytoskeletal breakdown and depletion in the optic nerves was the cardinal finding with variable myelin loss, even in the absence of overt visual dysfunction, or infective retinitis. The axonal loss was maximal in the symptomatic case. Retinal ganglion cell depletion was seen in only two patients. Sectoral infiltration of the optic nerve by cryptococci and Cryptococcal choroiditis was the only opportunistic infection to involve the eye. Axonal pathology in the optic nerve appears to be related to the abnormalities recorded in visual evoked potentials even in the absence of overt clinical symptoms. Opportunistic infections could be contributing to the axonal pathology in the optic nerve in patients with AIDS.     

Benign symmetrical lipomatosis (Madelung’S disease)

A case of benign symmetrical lipomatosis of neck in a 10 year, thinly built child is presented with outline of possible etiology and treatment. Since this disease barely finds mention in otolaryngotogy textbooks, although these patients usually first present to olotaryngologists, this case is reported to make aware the young fraternity with the disease entity.     

Recurrent Parotid Adenocarcinoma Presenting as Diffuse Myocardial Metastatic Disease

A 64-year-old man who had undergone treatment for left parotid adenocarcinoma presented with progressive exertional shortness of breath. Evaluation revealed metastatic invasion of the myocardium as a rare presentation of recurrent parotid adenocarcinoma. This case highlights the importance of using multimodal imaging methods in diagnostic evaluation and a collaborative multidisciplinary approach in managing patient care.