Drug-induced torsades de pointes and implications for drug development

Torsades de pointes is a potentially lethal arrhythmia that occasionally appears as an adverse effect of pharmacotherapy. Recently developed understanding of the underlying electrophysiology allows better estimation of the drug-induced risks and explains the failures of older approaches through the surface ECG. This article expresses a consensus reached by an independent academic task force on the physiologic understanding of drug-induced repolarization changes, their preclinical and clinical evaluation, and the risk-to-benefit interpretation of drug-induced torsades de pointes. The consensus of the task force includes suggestions on how to evaluate the risk of torsades within drug development programs. Individual sections of the text discuss the techniques and limitations of methods directed at drug-related ion channel phenomena, investigations aimed at action potentials changes, preclinical studies of phenomena seen only in the whole (or nearly whole) heart, and interpretation of human ECGs obtained in clinical studies. The final section of the text discusses drug-induced torsades within the larger evaluation of drug-related risks and benefits.     

Using cognitive-behavioural techniques to improve exclusive breastfeeding in a low-literacy disadvantaged population

Despite being an important component of Pakistan's primary health care programme, the rates of exclusive breastfeeding at 6 months remain among the lowest in the world. Low levels of literacy in women and deeply held cultural beliefs and practices have been found to contribute to the ineffectiveness of routine counselling delivered universally by community health workers in Pakistan. We aimed to address this by incorporating techniques of cognitive-behavioural therapy (CBT) into the routine counselling process. We conducted qualitative studies of stakeholders' opinions (mothers, community health workers, their trainers and programme managers) and used this data to develop a psycho-educational approach that combined education with techniques of CBT that could be integrated into the health workers' routine work. The workers were trained to use this approach and feedback was obtained after implementation. The new intervention was successfully integrated into the community health worker programme and found to be culturally acceptable, feasible and useful. Incorporating techniques of CBT into routine counselling may be useful to promote health behaviours in traditional societies with low literacy rates.     

FluBreaks: Early Epidemic Detection from Google Flu Trends

Background

The Google Flu Trends service was launched in 2008 to track changes in the volume of online search queries related to flu-like symptoms. Over the last few years, the trend data produced by this service has shown a consistent relationship with the actual number of flu reports collected by the US Centers for Disease Control and Prevention (CDC), often identifying increases in flu cases weeks in advance of CDC records. However, contrary to popular belief, Google Flu Trends is not an early epidemic detection system. Instead, it is designed as a baseline indicator of the trend, or changes, in the number of disease cases.

Objective

To evaluate whether these trends can be used as a basis for an early warning system for epidemics.

Methods

We present the first detailed algorithmic analysis of how Google Flu Trends can be used as a basis for building a fully automated system for early warning of epidemics in advance of methods used by the CDC. Based on our work, we present a novel early epidemic detection system, called FluBreaks (dritte.org/flubreaks), based on Google Flu Trends data. We compared the accuracy and practicality of three types of algorithms: normal distribution algorithms, Poisson distribution algorithms, and negative binomial distribution algorithms. We explored the relative merits of these methods, and related our findings to changes in Internet penetration and population size for the regions in Google Flu Trends providing data.

Results

Across our performance metrics of percentage true-positives (RTP), percentage false-positives (RFP), percentage overlap (OT), and percentage early alarms (EA), Poisson- and negative binomial-based algorithms performed better in all except RFP. Poisson-based algorithms had average values of 99%, 28%, 71%, and 76% for RTP, RFP, OT, and EA, respectively, whereas negative binomial-based algorithms had average values of 97.8%, 17.8%, 60%, and 55% for RTP, RFP, OT, and EA, respectively. Moreover, the EA was also affected by the region’s population size. Regions with larger populations (regions 4 and 6) had higher values of EA than region 10 (which had the smallest population) for negative binomial- and Poisson-based algorithms. The difference was 12.5% and 13.5% on average in negative binomial- and Poisson-based algorithms, respectively.

Conclusions

We present the first detailed comparative analysis of popular early epidemic detection algorithms on Google Flu Trends data. We note that realizing this opportunity requires moving beyond the cumulative sum and historical limits method-based normal distribution approaches, traditionally employed by the CDC, to negative binomial- and Poisson-based algorithms to deal with potentially noisy search query data from regions with varying population and Internet penetrations. Based on our work, we have developed FluBreaks, an early warning system for flu epidemics using Google Flu Trends.     

Bidirectional regulation of neutrophil migration by mitogen-activated protein kinases

To kill invading bacteria, neutrophils must interpret spatial cues, migrate and reach target sites. Although the initiation of chemotactic migration has been extensively studied, little is known about its termination. Here we found that two mitogen-activated protein kinases (MAPKs) had opposing roles in neutrophil trafficking. The extracellular signal-regulated kinase Erk potentiated activity of the G protein-coupled receptor kinase GRK2 and inhibited neutrophil migration, whereas the MAPK p38 acted as a noncanonical GRK that phosphorylated the formyl peptide receptor FPR1 and facilitated neutrophil migration by blocking GRK2 function. Therefore, the dynamic balance between Erk and p38 controlled neutrophil 'stop' and 'go' activity, which ensured that neutrophils reached their final destination as the first line of host defense.     

Zygodactyly with thumb aplasia: an unusual variant in a male subject

This is a presentation of a male subject with unusual combination of limb malformations. The subject had unilateral zygodactyly of the left foot with thumb aplasia in the right hand. Further, the webbing between second and third toes was complete culminating in osseous fusion of the terminal phalanges and valgus deviation of the affected digits of the foot. The nails were also involved but had separate origins. In the right hand, first digital ray was observed to be completely omitted. There was aplasia of certain carpals while the radius showed minimal clinical symptoms. The subject was the product of first cousins union. To the best of our knowledge, this combination of limb phenotype has not been described before.     

Bone marrow infection with Mycobacterium fortuitum in a diabetic patient

Incidence and prevalence of Mycobacterium fortuitum infection vary greatly by location and death is very rare except in disseminated disease in immunocompromised individuals. We present what we believe is the first case of bone marrow infection with Mycobacterium fortuitum in an HIV negative patient. Bone marrow examination revealed presence of numerous acid fast bacilli which were confirmed as Mycobacterium fortuitum on culture and by molecular analysis. Patient was managed successfully with amikacin and ciprofloxacin.