Mechanism for low renin in blacks: studies in hypophysectomised rat model

Black people have a lower plasma renin activity (PRA) than is appropriate for the level of blood pressure, but the mechanism remains unknown. Studies in our laboratory, using the hypophysectomised (Hypox) rat model, have provided a partial explanation of the inappropriately low PRA with respect to BP. Kidneys were isolated and perfused and renin secretion responsiveness studied with isoproterenol (Iso) infusion, calcium (Ca) depletion, and pressure reduction; an enriched preparation of juxtaglomerular (JG) cells was prepared for determination of cellular renin content (CRC); and preparations of isolated renin granules (IRG) and plasma membrane vesicles (PMV) from the purified JG cells were used to assess the storage and compartmentalisation of renin. Renin secretion was lower in Hypox than in normal and sodium (Na) deprived rats. On the other hand, CRC, IRG, and PMV were identical (statistically) in Hypox and Na deprived rats. Despite identical content and storage, kidneys from Hypox rats secreted significantly less renin in response to Iso, Ca depletion, and low pressure. One interesting observation is that upon stimulation, PMV of Hypox rats stored a much larger percentage of renin than normal or Na deprived rats, suggesting that the PMV may play a role as a renin sink in the low PRA levels observed in the Hypox rats. Since black people have renin profiles and responsiveness similar to those in Hypox rats, this model may be useful in studying the mechanisms responsible for their lower PRA.     

Do Internet interventions for consumers cause more harm than good? A systematic review

Objective  To systematically review the effect of consumer use of online health information on decision-making, attitudes, knowledge, satisfaction and health outcomes and utilization.
Search strategy  Electronic databases searched included the Cochrane Controlled Trials Register, MEDLINE, PREMEDLINE (to 14 March 2001), CINAHL, Australian Medical Index, Health and Society, National Institutes of Health Clinical Trials Database and CenterWatch.
Inclusion criteria  All post-1995 comparative studies (including controlled studies, before and after studies, and interrupted time series analyses) of Internet users vs. non-Internet users and other communications mediums, and Internet characteristics such as e-mail vs. other communication mediums, were included. Outcomes included consumer decision-making, attitudes, knowledge, satisfaction and measurable changes in health status or health utilization.
Data extraction and synthesis  One reviewer screened all papers then two reviewers independently assessed studies against the selection criteria and any discrepancies were resolved by discussion with a third reviewer. No attempt was made to combine the data for further statistical analysis.
Main results  We identified 10 comparative studies. Studies evaluated the effectiveness of using the Internet to deliver a smoking cessation programme, cardiac and nutrition educational programmes, behavioural interventions for headache and weight loss, and pharmacy and augmentative services. All studies showed some positive effects on health outcomes, although the methodological quality of many studies was poor.
Conclusions  Despite widespread consumer Internet use to obtain health-care information, there is almost a complete lack of evidence of any effects this may have on health outcomes.     

Spondylometaphyseal dysplasia, corner fracture type: a heritable condition associated with coxa vara

The authors present the radiographic features of a previously incompletely delineated bone dysplasia, which they call spondylometaphyseal dysplasia, corner fracture type. This is a dominant heritable condition associated with short stature and developmental coxa vara. The progressive hip deformity usually causes significant disability requiring surgical correction. Developmental coxa vara, simulated corner fractures of long tubular bones, and vertebral body abnormalities result in a diagnostic constellation. Knowledge of these distinctive radiologic features allows accurate diagnosis, which in turn should lead to appropriate genetic counseling and possibly to earlier, more efficacious surgical treatment of the coxa vara.     

Primary headache care delivery by nonspecialists in Brazil

Headaches are common disorders usually examined by nonneurologists. In order to assess how primary headache patients (IHS groups 1, 2, and 3) are generally managed by nonspecialists, 414 patients were asked about their previous headache care. Correct diagnosis had previously been made in only 44.9%, 6.7%, and 26.7% of the migraine, tension-type headache, and cluster headache patients, respectively. The patients underwent 501 investigative procedures motivated by the headache, averaging 1.21 examinations per patient, mostly EEGs. Preventive treatment was largely overlooked irrespective of the headache type. It is concluded that scientific improvements in headache care may be ineffective unless educational programs improve headache knowledge in general.     

No brain structure abnormalities in boys with Tourette's syndrome: A voxel‐based morphometry study

Morphometric findings in Tourette's syndrome (TS) are still inconsistent probably due to differences in analysis approaches as well as several confounders (coexisting psychiatric conditions, medication status, etc.). Our aim was to identify possible morphometric changes in a well‐defined sample of drug‐naïve boys with “pure” TS. High‐resolution structural magnetic resonance images of 38 boys with TS were compared with those of 38 healthy boys matched for age and IQ using voxel‐based morphometry (VBM). Coexisting psychiatric conditions and previous medication were excluded. The inclusion of 10‐ to 15‐year‐old boys minimized the well known compensatory changes due to tic suppression over many years. VBM analyses revealed no differences between the treatment naïve boys with “pure” TS and healthy controls. Brain morphology is not altered in boys with “pure” TS. Further studies should reveal whether previous findings might be ascribed to confounding factors like coexisting psychiatric conditions or long‐term compensatory mechanisms due to voluntary tic suppression. © 2009 Movement Disorder Society