Plasticity and impact of the central renin–angiotensin system during development of ethanol dependence

Pharmacological and genetic interference with the renin-angiotensin system (RAS) seems to alter voluntary ethanol consumption. However, understanding the influence of the RAS on ethanol dependence and its treatment requires modeling the neuroadaptations that occur with prolonged exposure to ethanol. Increased ethanol consumption was induced in rats through repeated cycles of intoxication and withdrawal. Expression of angiotensinogen, angiotensin-converting enzyme, and the angiotensin II receptor, AT1a, was examined by quantitative reverse transcription polymerase chain reaction. Increased ethanol consumption after a history of dependence was associated with increased angiotensinogen expression in medial prefrontal cortex but not in nucleus accumbens or amygdala. Increased angiotensinogen expression also demonstrates that the astroglia is an integral part of the plasticity underlying the development of dependence. The effects of low central RAS activity on increased ethanol consumption were investigated using either spirapril, a blood-brain barrier-penetrating inhibitor of angiotensin-converting enzyme, or transgenic rats (TGR(ASrAOGEN)680) with reduced central angiotensinogen expression. Spirapril reduced ethanol intake in dependent rats compared to controls. After induction of dependence, TGR(ASrAOGEN)680 rats had increased ethanol consumption but to a lesser degree than Wistar rats with the same history of dependence. These data suggest that the central RAS is sensitized in its modulatory control of ethanol consumption in the dependent state, but pharmacological or genetic blockade of the system appears to be insufficient to halt the progression of dependence.

Effects on leg muscular performance from whole-body vibration exercise: a systematic review

The purpose of this study was to investigate the effects on leg muscular performance from whole-body vibration exercise. Literature search was performed on the databases Pubmed, Cinahl, ISI web of science (Sci-expanded, SSCI) and Embase (Rehab & Physical Med). Rating of 19 relevant studies was performed (14 on long-term exercise and five on short-term exercise) using a score system for the methodological quality. Several randomized-controlled trial studies of high to moderate quality show similar improvements from long-term regimen on muscular performance in the legs after a period of whole-body vibration exercise. As there were few studies on short-term exercise and as they had no control groups, the same convincing improvements regarding muscular performance were not achieved. Preliminarily, there is strong to moderate evidence that long-term whole-body vibration exercise can have positive effects on the leg muscular performance among untrained people and elderly women. There is no clear evidence for effects on muscular performance after short-term vibration stimuli.

Scoliosis in Rett syndrome. Clinical and biological aspects

STUDY DESIGN

The natural history of progression of scoliosis was studied. The authors included a wide range of ages and correlated progression and progression rate to both age of the patient and the neurobiologic staging of the disease.

OBJECTIVES

The authors studied information compiled by Hagberg and coworkers regarding Rett syndrome. The total number of patients was 78, with age ranging from 1 to 34 years. Standing or sitting anteroposterior roentgenograms were collected and measured.

METHOD

The material was studied initially separately regarding orthopedic and radiologic analysis on one hand and neurobiologic staging on the other. Radiographic films were measured both retrospectively and prospectively, and scoliosis angle and progression and progression rate was calculated. Staging of patients with Rett syndrome was done according to Hagberg.

RESULTS

When correlating curve magnitude and progression, the authors found that patients progressing > 15 degrees/year were classified as IV-A or IV-B stages. In the 0-5 year group, of the patients already having a curve of 15 degrees or more, all but one rapidly progressed to stage IV. The ten worst cases were characterized by early hypotonia, weakness, and gross motor disturbance.

CONCLUSIONS

The scoliosis in Rett syndrome is of a neurogenic type, and it develops earlier than idiopathic scoliosis. The development of scoliosis is dependent more on stage of disease than on age. Curve progression is usually more rapid than in idiopathic scoliosis and in most other types of neurogenic scoliosis in childhood and occurs in a broader age span. Early hypotonia, weakness, and muscular insufficiency, and an early clinical referral to disease stages IV-A or IV-B are ominous factors. Clinical follow-up should begin early and be repeated regularly and frequently.

Postural control in siblings to scoliosis patients and scoliosis patients

The etiologic importance of postural dysfunction, as shown by many authors in adolescent idiopathic scoliosis (AIS), has been under great debate. The authors' hypothesis was that a factor that is involved in the development of the scoliotic curvature, would be present also in nonscoliotic siblings to scoliosis patients, as AIS is a hereditary transmitted disease. Postural function in 100 siblings to scoliotic children was investigated by means of stabilometry, and compared with a matched control group of healthy children, as well as a group of scoliotic children. The siblings showed a postural control function that was significantly different from both of the other groups. The siblings had a postural sway that was less than the sway measured in both controls and scoliosis patients. The sway was also more asymmetrical than in the two other groups. In the authors' opinion, the presence of this postural aberration in siblings indicates that it is a factor in the etiology of AIS.

Equilibrium factors as predictors of the prognosis in adolescent idiopathic scoliosis

Postural equilibrium factors were evaluated as indicators of the prognosis in 52 patients with adolescent idiopathic scoliosis. The hypothesis was that dysfunction in these equilibrium factors might imply a higher risk for the curve to progress. The postural equilibrium was studied by stabilometry, and the function of the central nervous system was assessed by electoencephalography (EEG) and the vestibular function by electronystomography (ENG). During a follow-up period averaging 2.9 years, ten patients showed progression of the scoliosis. No differences were found in the distribution and frequency of abnormalities between the patients with progressive and nonprogressive scoliosis. Stabilometry, electroencephalography, and electronystomography as used in this study did not seem to be of predictive value for the outcome in the individual case.