Gene for CF severity

The considerable contribution of lung disease to the morbidity and mortality of cystic fibrosis has been targeted by an international group of researchers, who have aimed to clarify the role of neutrophils in the chronic inflammation and airway destruction that characterise the condition. Cystic fibrosis, caused by mutations in the CFTR gene, shows clinical variations in severity, apparently independent of the CFTR genotype. By performing a genome-wide single nucleotide polymorphism scan, scientists were able to identify a gene, IFRD1, which appears to modify disease severity. The gene encodes a protein that regulates the function of neutrophils. Mice in which the IFRD1 gene was deleted showed delayed clearance of bacteria from the airways, but also less inflammation and disease. The authors comment that the identification of IFRD1 could be a potential lead in future therapy for cystic fibrosis.

Nature 2009; 458: 1039-1042

Virtual reality surgery

Virtual reality training for surgeons learning to perform laparoscopic procedures im-proves performance and decreases operation time, say Canadian and Danish researchers. In a randomised controlled and blinded trial, registrars in obstetrics and gynaecology were allocated to two groups — laparoscopic salpingectomy training using a virtual reality simulator or a control group following standard clinical education. When performing an actual procedure, the simulator-trained group demonstrated increased proficiency comparable to the experience gained after 20-50 laparoscopic procedures, as opposed to fewer than five procedures in the control group. The virtual reality-trained registrars also showed a significant reduction in operation time. The authors conclude that virtual reality simulator training can improve patient safety and operating theatre efficiency.

BMJ 2009; 338: b1802

Keratitis cluster

A severe keratitis caused by Acanthamoeba, a common free-living amoeba, is becoming more common worldwide, and a cluster of cases has been recently described in Brisbane, say Australian ophthalmologists.1 In response to an observed increase in patients with Acanthamoeba keratitis, the authors conducted a retrospective, consecutive case-series study. Although the infection appeared to be associated with the use of soft contact lenses and a type of contact lens solution implicated in a previous outbreak in the US, the small number of patients precluded any definite conclusions as to the association. An accompanying review emphasises the importance of early diagnosis of this potentially devastating keratitis, and advises clinicians to have a high level of suspicion when presented with an atypical keratitis.2

1 Clin Exp Ophthal 2009; 37: 181-190

2 Clin Exp Ophthal 2009; 37: 232-238

Oestradiol and heart failure

The role of oestrogens in chronic heart failure (CHF) has been clarified by the results of a Polish prospective observational study involving over 500 men with CHF or reduced left ventricular ejection fraction. Working from the established finding that androgen deficiency is common in men with CHF, researchers measured serum concentrations of oestradiol and androgens in all participants and collected data on mortality during the 3-year follow-up. Results showed a U-shaped outcome in relation to oestradiol concentrations: low and high levels of oestradiol were significant predictors of poor prognosis, independent of other prognostic indicators. Differences in clinical characteristics of men with low and high oestradiol were observed. The authors note the question of whether oestradiol is a causative factor or a marker of disease progression.

JAMA 2009; 301: 1892-1901

Dr Tanya Grassi, MJA

©The Medical Journal of Australia 2005 www.mja.com.au PRINT ISSN: 0025-729X ONLINE ISSN: 1326-5377