Immune thrombocytopenia in adults: An update

Immune thrombocytopenia (ITP) in adults is a chronic disease resulting from increased platelet destruction and impaired platelet production. Splenectomy remains the most effective and durable treatment in cases that are refractory to first-line therapy, but its use has declined because of the availability of alternate medical therapy, the associated risk of infection, and concern for surgery-related complications. Rituximab (Rituxan) may be an effective alternative but carries the risk of immunosuppression.     

Dissociating hippocampal and striatal contributions to sequential prediction learning

Behavior may be generated on the basis of many different kinds of learned contingencies. For instance, responses could be guided by the direct association between a stimulus and response, or by sequential stimulus-stimulus relationships (as in model-based reinforcement learning or goal-directed actions). However, the neural architecture underlying sequential predictive learning is not well understood, in part because it is difficult to isolate its effect on choice behavior. To track such learning more directly, we examined reaction times (RTs) in a probabilistic sequential picture identification task in healthy individuals. We used computational learning models to isolate trial-by-trial effects of two distinct learning processes in behavior, and used these as signatures to analyse the separate neural substrates of each process. RTs were best explained via the combination of two delta rule learning processes with different learning rates. To examine neural manifestations of these learning processes, we used functional magnetic resonance imaging to seek correlates of time-series related to expectancy or surprise. We observed such correlates in two regions, hippocampus and striatum. By estimating the learning rates best explaining each signal, we verified that they were uniquely associated with one of the two distinct processes identified behaviorally. These differential correlates suggest that complementary anticipatory functions drive each region's effect on behavior. Our results provide novel insights as to the quantitative computational distinctions between medial temporal and basal ganglia learning networks and enable experiments that exploit trial-by-trial measurement of the unique contributions of both hippocampus and striatum to response behavior.     

Anterior prefrontal cortex contributes to action selection through tracking of recent reward trends

The functions of prefrontal cortex remain enigmatic, especially for its anterior sectors, putatively ranging from planning to self-initiated behavior, social cognition, task switching, and memory. A predominant current theory regarding the most anterior sector, the frontopolar cortex (FPC), is that it is involved in exploring alternative courses of action, but the detailed causal mechanisms remain unknown. Here we investigated this issue using the lesion method, together with a novel model-based analysis. Eight patients with anterior prefrontal brain lesions including the FPC performed a four-armed bandit task known from neuroimaging studies to activate the FPC. Model-based analyses of learning demonstrated a selective deficit in the ability to extrapolate the most recent trend, despite an intact general ability to learn from past rewards. Whereas both brain-damaged and healthy controls used comparisons between the two most recent choice outcomes to infer trends that influenced their decision about the next choice, the group with anterior prefrontal lesions showed a complete absence of this component and instead based their choice entirely on the cumulative reward history. Given that the FPC is thought to be the most evolutionarily recent expansion of primate prefrontal cortex, we suggest that its function may reflect uniquely human adaptations to select and update models of reward contingency in dynamic environments.     

Quality control issues and the identification of rare functional variants with next-generation sequencing data

Next-generation sequencing of large numbers of individuals presents challenges in data preparation, quality control, and statistical analysis because of the rarity of the variants. The Genetic Analysis Workshop 17 (GAW17) data provide an opportunity to survey existing methods and compare these methods with novel ones. Specifically, the GAW17 Group 2 contributors investigate existing and newly proposed methods and study design strategies to identify rare variants, predict functional variants, and/or examine quality control. We introduce the eight Group 2 papers, summarize their approaches, and discuss their strengths and weaknesses. For these investigations, some groups used only the genotype data, whereas others also used the simulated phenotype data. Although the eight Group 2 contributions covered a wide variety of topics under the general idea of identifying rare variants, they can be grouped into three broad categories according to their common research interests: functionality of variants and quality control issues, family-based analyses, and association analyses of unrelated individuals. The aims of the first subgroup were quite different. These were population structure analyses that used rare variants to predict functionality and examine the accuracy of genotype calls. The aims of the family-based analyses were to select which families should be sequenced and to identify high-risk pedigrees; the aim of the association analyses was to identify variants or genes with regression-based methods. However, power to detect associations was low in all three association studies. Thus this work shows opportunities for incorporating rare variants into the genetic and statistical analyses of common diseases.     

Switching Health Insurance Plans: Results from a Health Survey

The study is designed to provide an informal summary of what is known about consumer switching of health insurance plans and to contribute to knowledge about what motivates consumers who choose to switch health plans. Do consumers switch plans largely on the basis of critical reflection and assessment of information about the quality, and price? The literature suggests that switching is complicated, not always possible, and often overwhelming to consumers. Price does not always determine choice. Quality is very hard for consumers to understand. Results from a random sample survey (n = 2791) of the Alkmaar region of the Netherlands are reported here. They suggest that rather than embracing the opportunity to be active critical consumers, individuals are more likely to avoid this role by handing this activity off to a group purchasing organization. There is little evidence that consumers switch plans on the basis of critical reflection and assessment of information about quality and price. The new data reported here confirm the importance of a group purchasing organizations. In a free-market-health insurance system confidence in purchasing groups may be more important for health insurance choice than health informatics. This is not what policy makers expected and might result a less efficient health insurance market system.     

An unbalanced (6q;13q) translocation in a male with clinical features of Ehlers-Danlos type II syndrome.

Ehlers-Danlos syndrome has been divided into several different types according to the variety and severity of clinical manifestations, and may follow autosomal dominant, autosomal recessive, or X linked patterns of inheritance. Only rarely have chromosome anomalies been seen in patients manifesting phenotypic features of the syndrome and most are considered insignificant. However, one case report involved a balanced t(9;17)(q34;q11) in a female with the clinical features of Ehlers-Danlos type I and IV syndromes and, as noted by McKusick: "It is possible, furthermore, that certain very rare syndromes that are transmitted in a Mendelian manner are the result of small chromosome aberrations, such as deletion or inversion, affecting the action of several genes". We present a 14 year old male with features of Ehlers-Danlos type II syndrome and an unbalanced (6q;13q) translocation.     

The epidemiology of lip cancer: a review of global incidence and aetiology

Lip cancer (140 ICD-9) is a form of oral cancer that has a distinctive global epidemiology. This review summarises global incidence rates for male and female lip cancer with the aid of cancer atlases. High male lip cancer rates are reported for regions of North America (12.7 per 100 000 per annum), Europe (12.0 per 100 000 per annum) and Oceania (13.5 per 100 000 per annum), while it is virtually unknown in parts of Asia. Factors commonly cited as important in the aetiology of lip cancer include solar radiation, tobacco smoking and viruses. An attempt is made to summarise the evidence for factors that may be important in lip carcinogenesis. While incidence rates are generally stable or falling among males worldwide, they are rising in many female populations. The aetiology of the disease is far from established and much information regarding its pathogenesis is based on anecdotal rather than case-controlled epidemiological evidence. The epidemiology of lip cancer supports the proposal that the lip should be considered as a distinct cancer site, rather than being included with other forms of intraoral cancer.     

Magnetic Resonance Imaging Reveals Micro-haemorrhage in the Feet of Diabetic Patients with a History of Ulceration

Soft tissue haemorrhage in the foot is a possible precursor of ulceration in patients with diabetic peripheral neuropathy. High resolution ‘targetted’ magnetic resonance imaging was used to scan the forefoot. Neuropathic patients with and without previous ulceration were matched for degree of neuropathy, mean vibration perception threshold 33.5 ± 4.2 V (previous ulcer) vs 31.0 ± 6.9 V (no ulcer), age, sex, and duration of diabetes against non-neuropathic controls. There were nine patients in each category. Paramagnetic materials, e.g. iron compounds, cause a signal void (‘drop-out’) on gradient-echo images which disappear on spin-echo images. Evidence of haemorrhage was seen in 6 patients with previous ulceration, and none in the other groups (p = 0.009, chi square test). Autologous injection of 20 μl of blood into the foot of a healthy volunteer produced similar images, a ‘drop-out’ 1 cm across being visible on magnetic resonance scanning 3 days later. Peak vertical forefoot pressures were not significantly different in the neuropathic groups 0.67 ± 0.20 vs 0.60 ± 0.13 Pa but were lower in the non-neuropathic group, 0.43 ± 0.11 Pa (p = 0.0004, Mann-Whitney), and do not explain the appearance of these haemorrhages. Magnetic resonance imaging provides a sensitive way of detecting micro-haemorrhage and its presence may predict an increased risk of foot ulceration.     

Comparison of treatment modalities in burning mouth syndrome

Background: Burning mouth syndrome (BMS) is characterized by a spontaneous burning pain in the oral mucosa without known organic cause or standardized treatment. The aims of this study were to assess and compare the efficacy of clonazepam and diazepam in relieving the symptoms associated with BMS and evaluate for which patients this treatment might be effective by correlating treatment efficacy with underlying psychological status. Methods: The medical records of BMS patients attending an oral medicine private practice (1999–2004) were reviewed. The patients were then contacted and asked to complete a short questionnaire regarding their response to diazepam/clonazepam drug therapies. A second group of patients attending the above clinic (n = 30) were asked to fill out a hospital anxiety and depression assessment form in an attempt to correlate treatment success with underlying psychological status. Results: A total of 71.4 per cent of patients treated with clonazepam had partial or complete resolution of their oral symptoms, while 55.1 per cent of patients treated with diazepam had improvement of their oral symptoms. There was no correlation between underlying anxiety or depression and efficacy of benzodiazepine medication. Conclusions: A greater percentage of patients taking clonazepam reported either partial or complete relief of symptoms compared to diazepam. However, the differences were not statistically significant. There was no correlation found between underlying psychopathology and treatment success with benzodiazepines.