Bilateral fibular fractures in a pre-ambulant infant

Multiple long-bone fractures, particularly bilateral fractures, are of moderate specificity for inflicted injury (physical abuse) in infants and young children. Bilateral healing fractures of the fibulae are rare and, depending on age, raise the suspicion of inflicted injury. We report healing undisplaced fractures of both fibulae, in almost identical positions, in a pre-ambulant infant. The caregivers reported that the infant repeatedly banged his legs against the metal frame of his playpen. A video of this mechanism was provided to the instructed radiology expert and showed that the point of impact of the infant’s legs against the metal frame was at a similar level to the radiographic abnormalities. This mechanism was therefore believed to be consistent with the injuries, resulting in a diagnosis of self-inflicted bilateral fibular fractures and not of inflicted injury

Mycobacterium tuberculosis monoarthritis in a child

A child with isolated Mycobacterium tuberculosis monoarthritis, with features initially suggesting oligoarthritis subtype of juvenile idiopathic arthritis, is presented. This patient illustrates the need to consider the possibility of tuberculosis as the cause of oligoarthritis in high-risk pediatric populations even in the absence of a tuberculosis contact history and without evidence of overt pulmonary disease

Is computer aided detection (CAD) cost effective in screening mammography? A model based on the CADET II study

BACKGROUND: Single reading with computer aided detection (CAD) is an alternative to double reading for detecting cancer in screening mammograms. The aim of this study is to investigate whether the use of a single reader with CAD is more cost-effective than double reading. METHODS: Based on data from the CADET II study, the cost-effectiveness of single reading with CAD versus double reading was measured in terms of cost per cancer detected. Cost (Pound (£), year 2007/08) of single reading with CAD versus double reading was estimated assuming a health and social service perspective and a 7 year time horizon. As the equipment cost varies according to the unit size a separate analysis was conducted for high, average and low volume screening units. One-way sensitivity analyses were performed by varying the reading time, equipment and assessment cost, recall rate and reader qualification. RESULTS: CAD is cost increasing for all sizes of screening unit. The introduction of CAD is cost-increasing compared to double reading because the cost of CAD equipment, staff training and the higher assessment cost associated with CAD are greater than the saving in reading costs. The introduction of single reading with CAD, in place of double reading, would produce an additional cost of £227 and £253 per 1,000 women screened in high and average volume units respectively. In low volume screening units, the high cost of purchasing the equipment will results in an additional cost of £590 per 1,000 women screened.One-way sensitivity analysis showed that the factors having the greatest effect on the cost-effectiveness of CAD with single reading compared with double reading were the reading time and the reader's professional qualification (radiologist versus advanced practitioner). CONCLUSIONS: Without improvements in CAD effectiveness (e.g. a decrease in the recall rate) CAD is unlikely to be a cost effective alternative to double reading for mammography screening in UK. This study provides updated estimates of CAD costs in a full-field digital system and assessment cost for women who are re-called after initial screening. However, the model is highly sensitive to various parameters e.g. reading time, reader qualification, and equipment cost

Wolbachia infections that reduce immature insect survival: Predicted impacts on population replacement

<p>Abstract</p> <p>Background</p> <p>The evolutionary success of <it>Wolbachia </it>bacteria, infections of which are widespread in invertebrates, is largely attributed to an ability to manipulate host reproduction without imposing substantial fitness costs. Here, we describe a stage-structured model with deterministic immature lifestages and a stochastic adult female lifestage. Simulations were conducted to better understand <it>Wolbachia </it>invasions into uninfected host populations. The model includes conventional <it>Wolbachia </it>parameters (the level of cytoplasmic incompatibility, maternal inheritance, the relative fecundity of infected females, and the initial <it>Wolbachia </it>infection frequency) and a new parameter termed relative larval viability (<it>RLV</it>), which is the survival of infected larvae relative to uninfected larvae.</p> <p>Results</p> <p>The results predict the <it>RLV </it>parameter to be the most important determinant for <it>Wolbachia </it>invasion and establishment. Specifically, the fitness of infected immature hosts must be close to equal to that of uninfected hosts before population replacement can occur. Furthermore, minute decreases in <it>RLV </it>inhibit the invasion of <it>Wolbachia </it>despite high levels of cytoplasmic incompatibility, maternal inheritance, and low adult fitness costs.</p> <p>Conclusions</p> <p>The model described here takes a novel approach to understanding the spread of <it>Wolbachia </it>through a population with explicit dynamics. By combining a stochastic female adult lifestage and deterministic immature/adult male lifestages, the model predicts that even those <it>Wolbachia </it>infections that cause minor decreases in immature survival are unlikely to invade and spread within the host population. The results are discussed in relation to recent theoretical and empirical studies of natural population replacement events and proposed applied research, which would use <it>Wolbachia </it>as a tool to manipulate insect populations.</p

Why Does It Take Longer to Read Digital Than Film-Screen Screening Mammograms? A Partial Explanation

Digital screening mammograms (DM) take longer to interpret than film-screen screening mammograms (FSM). We evaluated what part of the process takes long in our reading environment. We selected cases from those for which timed readings had been performed as part of a previous study. Readers were timed as they performed various computer manipulations on groups of DM cases and as they moved the alternator and adjusted lighting and manual shutters for FSM cases. Subtracting manipulation time from the original interpretation times yielded estimated times to reach a decision. Manipulation times for DM ranged from a low of 11 s when four-view DM were simply opened and closed in a 4-on-1 hanging protocol before moving on to the next study to 113.8 s when each view of six-view DM were brought up 1-on-1, enlarged to 100% resolution, and panned through. Manipulation times for groups of FSM ranged from 8.3 to 12.1 s. Estimated decision-making times for DM ranged from 128.0 to 202.2 s, while estimated decision-making time for FSM ranged from 60.9 to 146.3 s. Computer manipulation time partially explains the discrepancy in interaction times between DM and FSM. Radiologists also appear to spend more time looking at DM than at FSM before making a decision