Differences between bone mineral density, lean and fat mass of HIV-positive and HIV-negative black women

Objectives: To investigate the differences between bone mineral density (BMD), lean and fat mass of human immunodeficiency virus (HIV-) positive and HIV-negative black women and to investigate factors associated with low BMD. Methods: Case-control study of black women (n= 565) aged 29­65 years from Potchefstroom, North West province, South Africa, based on secondary analysis of data. Total BMD, left femur neck of the hip (LFN BMD), spine BMD, total fat, fat-free tissue mass and percentage body fat (%BF) were measured by dual-energy X-ray absorptiometry. Results: HIV-negative women had significantly higher median BMD, %BF, appendicular skeletal mass (ASM), ASM index, body mass index (BMI) and waist circumference than HIV-positive women. When the groups were matched for age and BMI, only spine BMD was marginally lower in HIV-positive women. In the total group, age, smoking and HIV status were associated with lower BMD, while calcium intake was positively associated with BMD. Similar variables were associated with BMD in HIV-negative women, while age and educational status were associated with BMD in HIV-positive women. Conclusion: Low BMD was more common among HIV-positive than HIV-negative women. Older HIV-positive women with low educational status are particularly at risk

Lessons from altered states of consciousness

Key research related to consciousness is that which investigates the neural systems that are deactivated or attenuated during altered states of consciousness, as well as during unconsciousness. This paper addresses various states of altered consciousness such as anaesthesia; sleep; vegetative states, seizures, post-LSD hallucinations, the minimally conscious state, locked-in syndrome, comatose states and thalamocortical dysrhythmia. Anaesthetics have been shown to act at all levels of integration in the central nervous system, with a wide range of known targets. Various conflicting theories regarding the anaesthetic state exist and a few are examined in this paper. In general, studies into altered states of consciousness emphasize the central role of prefrontal activity, the diffuse brain connectivity and the participation of the thalamocortical system/reticular formation in the maintenance of consciousness

The Effect of Sympathomimetic Medication on Cardiovascular Functioning of Children with Attention-Deficit / Hyperactivity Disorder : Cardiovascular Topic

Objective : The aim of this study was to investigate the effects of sympathomimetic medication on the cardiovascular system of children with attention-deficit / hyperactivity disorder (ADHD). Methods : Cardiovascular functioning of children with ADHD (n = 19) was tested while the children were stimulant free and during a period in which they were on stimulant medication. Electrocardiograms (ECGs) were obtained by means of a Schiller CardioLaptop AT-110 ECG recorder using the standard 12-lead cable positioning for a resting ECG. Blood pressure was measured by means of a stethoscope and mercury sphygmomanometer. Results : The main findings of this study were that methylphenidate usage is associated with increases in heart rate (HR) and blood pressure (BP); and that it does not adversely affect HR-corrected QT and JT intervals or cardiac dispersion values. Conclusion : Methylphenidate causes an increase in HR as well as increases in both systolic and diastolic BP; but no change in cardiac depolarisation and repolarisation duration or homogeneity

Neurological Aspects of Stuttering : Summary Overview of Scientific Fingings

The aim of this article is to provide a summary overview of some of the more important scientific evidence of neurological differences between stutterers and non-stutterers. Stuttering is a complex disorder of speech fluency; the aetiology of which is still largely unclear. Although most of the knowledge about stuttering has been derived from clinical observations; essential information obtained through laboratory research delineated some important neurological differences between people with a stuttering problem and people who do not stutter. These differences are identified in terms of neuroimaging; speech production processes and even in terms of auditory perception and feedback mechanisms. The development of new and improved neuroimaging techniques has greatly enhanced the potential to investigate neurological correlates of stuttering. Current knowledge is indicative of a complex neurological basis for stuttering. However; on the basis of current scientific evidence any currently held theory cannot be conclusively substantiated