Search

Fragile X-associated tremor ataxia syndrome (FXTAS) is a recently identified X-linked neurodegenerative disorder affecting a proportion of premutation carriers of the Fragile X Mental Retardation 1 ( FMR1) gene. Previous research suggests that cognitive and psychiatric features of FXTAS may include primary impairments in executive function and increased vulnerability to mood and anxiety disorders. A number of these reports, however, are based on overlapping cohorts or have produced inconsistent findings. A systematic review was therefore conducted to further elucidate the neuropsychiatric features characteristic of FXTAS. Fourteen papers met inclusion criteria for the review and were considered to represent nine independent FXTAS cohorts. Findings from the review suggest that the neuropsychiatric phenotype of FXTAS is characterised primarily by poorer performance on measures of executive function, working memory, information processing speed, and fine motor control when compared to matched comparison groups. Two studies were identified in which psychiatric symptoms in FXTAS were compared with controls, and these yielded mixed results. Overall the results of this review support previous reports that the neuropsychiatric profile of FXTAS is consistent with a dysexecutive fronto-subcortical syndrome. However, additional controlled studies are required to progress our understanding of FXTAS and how the neuropsychiatric profile relates to underlying pathological mechanisms. [ABSTRACT FROM AUTHOR]

Capillary haemangioma or infantile haemangioma (IH) is the most common congenital vascular tumour in the periocular region. Several treatment modalities have been documented, with variable degree of success. Propranolol has recently been reported to be an effective and safe alternative. The aim of this systematic review is to examine the evidence base for the use of propranolol administered orally in the management of periocular capillary haemangioma, and use this information to guide future research. A systematic review of literature was carried out by two independent reviewers using the search strategies highlighted below. A total of 100 cases of oral propranolol use in periorbital or orbital capillary haemangiomas have been documented in the literature. Of the 85 cases that had details of previous treatment, it was used as first-line treatment in 50 (58.8%). The commonest dose used was 2 mg/kg/day. Adverse events were documented in one-third of cases; in most cases these were minor. Improvement or complete resolution of the lesions occurred in 96% of cases. Recurrence was noted in one-fifth of cases. Propranolol has shown a lot of promise in the therapy of IH and further research in the form of properly designed randomized trials is certainly warranted. Treatment guidelines based on literature available to date is included in this review. [ABSTRACT FROM AUTHOR]

Association between attention-deficit hyperactivity disorder (ADHD) and the 10-repeat allele of the dopamine transporter gene (DAT1) has been reported in independent clinical samples using a categorical clinical definition of ADHD. The present study adopts a quantitative trait loci (QTL) approach to examine the association between DAT1 and a continuous measure of ADHD behaviours in a general-population sample, as well as to explore whether there is an independent association between DAT1 and performance on neuropsychological tests of attention, response inhibition, and working memory. From an epidemiological sample of 872 boys aged 6–11 years, we recruited 58 boys scoring above the 90th percentile for teacher reported ADHD symptoms (SWAN ADHD scale) and 68 boys scoring below 10th percentile for genotyping and neuropsychological testing. A significant association was found between the DAT1 homozygous 10/10-repeat genotype and high-scoring boys (χ2square=4.6, P<0.03; odds ratio=2.4, 95% CI 1.1–5.0). Using hierarchical linear regression, a significant independent association was found between the DAT1 10/10-repeat genotype and measures of selective attention and response inhibition after adjusting for age, IQ, and ADHD symptoms. There was no association between DAT1 and any component of working memory. Furthermore, performance on tasks of selective attention although associated with DAT1 was not associated with SWAN ADHD high scores after controlling for age and IQ. In contrast, impairment on tasks that tapped sustained attention and the central executive component of working memory were found in high-scoring boys after adjusting for age and IQ. The results suggest that DAT1 is a QTL for continuously distributed ADHD behaviours in the general population and the cognitive endophenotype of response inhibition.Molecular Psychiatry (2005) 10, 686–698. doi:10.1038/sj.mp.4001641 Published online 5 April 2005 [ABSTRACT FROM AUTHOR]

Rubber (cis-1,4-polyisoprene) is one of the most important polymers naturally produced by plants because it is a strategic raw material used in more than 40,000 products, including more than 400 medical devices. The sole commercial source, at present, is natural rubber harvested from the Brazilian rubber tree, Hevea brasiliensis. Primarily due to its molecular structure and high molecular weight (>1 million daltons) this rubber has high performance properties that cannot easily be mimicked by artificially produced polymers, such as those derived from, e.g., bacterial poly-hydroxy-alkanoates (PHAs). These high performance properties include resilience, elasticity, abrasion resistance, efficient heat dispersion (minimizing heat build-up under friction), and impact resistance. Medical rubber gloves need to fit well, be break-resistant, allow the wearer to retain fine tactile sensation, and provide an effective barrier against pathogens. The sum of all these characteristics cannot yet be achieved using synthetic gloves. The lack of biodiversity in natural rubber production renders continuity of supply insecure, because of the risk of crop failure, diminishing acreage, and other disadvantages outlined below. A search for alternative sources of natural rubber production has already resulted in a large number of interesting plants and prospects for immediate industrial exploitation of guayule (Parthenium argentatum) as a source of high quality latex. Metabolic engineering will permit the production of new crops designed to accumulate new types of valued isoprenoid metabolites, such as rubber and carotenoids, and new combinations extractable from the same crop. Currently, experiments are underway to genetically improve guayule rubber production strains in both quantitative and qualitative respects. Since the choice for gene activities to be introduced or changed is under debate, we have set up a complementary approach to guayule with yeast species, which may more quickly show the applicability and relevance of genes selected. Although economic considerations may prevent commercial exploitation of new rubber-producing microorganisms, transgenic yeasts and bacteria may yield intermediate or alternative (poly-)isoprenes suitable for specific applications. [ABSTRACT FROM AUTHOR]

Experiments were undertaken to determine the efferent path of the Bainbridge reflex and to investigate the interaction of the Bainbridge reflex with the Bezold-Jarisch reflex in conscious, chronically instrumented dogs. The Bainbridge reflex was elicited by distending the left atrium by inflating a chronically implanted balloon catheter. The Bezold-Jarisch reflex was elicited using chemical stimulation of left ventricular receptors with infusions of veratridine (0.1-0.8 μg/kg/min) into the left circumflex coronary artery. Heart-rate responses to left atrial balloon inflation were compared before and after either β-1 antagonism with metoprolol or cholinergic antagonism with atropine, and before and during left ventricular receptor stimulation with intracoronary veratridine. Left atrial balloon inflation alone caused a significant increase in heart rate (70.1 ± 5 bpm), left atrial pressure (14 ± 3 mm Hg) and mean arterial blood pressure (10 ± 2 mm Hg). Heart-rate responses to left atrial distension were inhibited, but not abolished by either cholinergic or β-1 antagonism. Left atrial distension after both cholinergic and β-1 antagonism abolished the heart-rate response to balloon inflation. These results indicate that the efferent component of the Bainbridge reflex has both a vagal and a sympathetic component in conscious dogs. Left atrial distension during simultaneous left ventricular receptor stimulation resulted in a significantly decreased tachycardia than did left atrial distension alone (26 ± 3 bpm compared to 68 ± 8 bpm in the control experiments). In addition, the slope of the heart rate vs left atrial pressure relationship was significantly inhibited by left ventricular receptor stimulation (1.8 ± 0.2 bpm/mm Hg compared to 5.7 ± 0.3 bpm/mm Hg in the control experiments). There were no significant differences in either the left atrial pressure or arterial blood pressure changes between the two groups. These data suggest an interaction between these two reflexes that may be occurring in the central nervous system. [ABSTRACT FROM AUTHOR]

PurposeTo report two cases of young diabetic patients with intractable neovascular glaucoma (NVG) who were successfully managed with bevacizumab and mitomycin C-augmented trabeculectomy.ResultsTwo young patients present with severe NVG secondary to diabetic proliferative retinopathy. The glaucoma was unresponsive to conventional medical therapy and complete panretinal photocoagulation. Both patients underwent augmented trabeculectomy with MMC and intravitreal injection of bevacizumab. Iris rubeosis resolved within 48 h. Both patients have a follow-up period of 6 months and the intraocular pressure (IOP) remain between 10–15 mmHg.ConclusionsControlling IOP due to NVG in young diabetic patients is difficult and augmented trabeculectomy has a very high failure rate. The addition of intravitreal bevacizumab in the management of NVG particularly in young diabetic patients may improve the success rate of IOP control. It is known that bevacizumab retards neovascularisation. It may also be modulating wound-healing response as well. Bevacizumab may have a potential role in the surgical management of NVG.Eye (2009) 23, 979–981; doi:10.1038/eye.2008.113; published online 2 May 2008 [ABSTRACT FROM AUTHOR]

A response from the authors of the article "The use of propranolol in the management of periocular capillary haemangioma-a systematic review" in the 2011 issue is presented.