AIDS Surveillance in Africa

Surveillance of the AIDS pandemic in Africa has always posed formidable problems for epidemiologists. Diagnostic accuracy-according to the case definitions for AIDS used in industrialised countries-is impossible to achieve in all but a few places with the right diagnostic facilities. Responding to the urgent need for surveillance, the World Health Organisation drew up a clinical case definition (the WHO/Bangui definition), which depended on clinical criteria without the need for serological verification.'2 Judged by its use, the WHO/Bangui definition has been successful-52 African countries have reported cases ofAIDS using mainly this definition.3 Some countries have modified it to fit local circumstances, removing a defining symptom here, adding the need for an extra sign there, and many now accept or encourage a positive result of an HIV test as supportive evidence. (At least one, COte d'Ivoire, requires such a result.2) Inevitably the definition has its limitations, and two papers in this week's journal discuss these at length (p 11852, p 11894). Because of limited laboratory facilities published evaluations of the WHO/Bangui definition have been mainly restricted to groups of sick patients using HIV positivity as the reference standard. The definition's sensitivity and specificity have been calculated as being between 60% and 90%2 5- useful for purposes of surveillance, but leaving uncertainty over whether this surveillance tool is intended to monitor trends in cases of AIDS or HIV infection. Other problems exist with the WHO/Bangui definition. Because many doctors lack diagnostic facilities they use the definition for diagnosis. The title "clinical case definition" encourages this confusion. The misuse is disturbing as the probability that a patient who fulfils the WHO/Bangui definition tests positive for HIV may fall well below 50% when seroprevalence is low.5 Another problem of using the definition is the delayed and incomplete picture that it gives of the spread of infection.6 Far preferable for surveillance of infection is the unlinked anonymous testing for HIV of sentinel groups attending health services67 (such as pregnant women and people with sexually transmitted diseases), which has now begun in several African countries89 using the same methods as in industrialised countries.'° Where does this leave the WHO/Bangui definition? De Cock and colleagues rehearse the overwhelming case for AIDS reporting to continue and suggest a thoughtful redesign of the definition, which includes the requirement for a positive HIV test result.3 Insisting on positive test results in all circumstances, however, is impractical: HIV tests are already limited and are lioely to become more so as AIDS funding to Africa inevitably falls. As a provisional solution to the problem of surveillance the WHO/Bangui definition has been useful, but the time has come for its reappraisal

Design and evaluation of a soft and wearable robotic glove for hand rehabilitation

In the modern world, due to an increased aging population, hand disability is becoming increasingly common. The prevalence of conditions such as stroke is placing an ever-growing burden on the limited fiscal resources of health care providers and the capacity of their physical therapy staff. As a solution, this paper presents a novel design for a wearable and adaptive glove for patients so that they can practice rehabilitative activities at home, reducing the workload for therapists and increasing the patient’s independence. As an initial evaluation of the design’s feasibility the prototype was subjected to motion analysis to compare its performance with the hand in an assessment of grasping patterns of a selection of blocks and spheres. The outcomes of this paper suggest that the theory of design has validity and may lead to a system that could be successful in the treatment of stroke patients to guide them through finger flexion and extension, which could enable them to gain more control and confidence in interacting with the world around them

Cardiac glycosides and breast cancer risk: A systematic review and meta-analysis of observational studies

Cardiac glycosides are phytoestrogens and have been linked to the risk of estrogen sensitive cancers such as uterus cancer. However, the association between use of cardiac glycosides and risk of breast cancer remains unclear. We investigated the association between cardiac glycosides use and the risk of breast cancer by systematically reviewing the published literature and performing meta-analyses. A comprehensive literature search was performed using MEDLINE, EMBASE, Web of Science and SCOPUS to identify all relevant articles published up to November 2015. Risk estimates, and accompanying standard errors, for the association between cardiac glycoside use and breast cancer were extracted from identified studies. Meta-analysis models were used to calculate a combined hazard ratio (HR), and 95% confidence interval (CI), and to investigate heterogeneity between studies. In total, 9 studies were identified investigating cardiac glycosides use and risk of developing breast cancer. Overall, there was evidence to suggest an association between cardiac glycosides use and breast cancer risk (HR=1.34; 95% CI 1.25, 1.44; p<0.001) with little variation in the association between studies (I2=16%, p for heterogeneity =0.30). Results were little altered when analysis was restricted to studies with high quality scores or cohort studies. Overall, there was a 34% increase in breast risk with use of cardiac glycosides but it is unclear whether this association reflects confounding or is causal. Further observational studies are required to examine this association particularly for estrogen receptor positive breast cancer and to explore the role of potential confounding variables

User-centric feedback for the development and review of a unique robotic glove prototype to be used in therapy

Disability can be a great impediment to daily living in later life and is often the result of illness or trauma. Modern thoughts on treatment are orientated towards the use of robotics; however, these are often designed without consultation with the user. This paper used a 5-point questionnaire to ask former therapy patients what they felt needed further improvements from potential robotics and what features of such a system were the most important. Significant emphasis was placed on helping them to grasp (M = 4.63) as well as having a functional use. They also desired a system with clearly distinguished (M = 4.22) and easy to operate controls (M = 4.44) whilst allowing them some freedom to move around independently (M = 4.44). This provided the rationale for a prototype dual-layered vacuum glove that was sampled by healthcare staff to provide feedback that forms the basis for future improvements

The activated torsion oscillation magnetometer

The activated torsion oscillation magnetometer exploits the mechanical resonance of a cantilever beam, driven by the torque exerted on the sample by an ac field applied perpendicularly to the film plane. We describe a model for the cantilever dynamics which leads to the calculation of the cantilever dynamic profile and allows the mechanical sensitivity of the instrument to be expressed in terms of the minimum electronically detectable displacement. We have developed a capacitance detector of small oscillations which is able to detect displacements of the order of 0.1 nm. We show that sensitivities of the order of 0.5(10-11 Am2 can be in principle achieved. We will subsequently describe the main features of the ATOM prototype which we have built and tested, with particular attention to the design solutions which have been adopted in order to reduce the effects of parasitic vibrations due either to acoustic noise, originating from the ac field coil, or to eddy currents in the capacitor electrodes. The instrument is mounted in a continuous flow cryostat and can work in the 4.2-300 K temperature range. Finally, we will show that our experimental set-up has a second mode of operation, named Torsion Induction Magnetometer (TIM).Comment: Invited Talk at the Moscow International Symposium on Magnetism, 2002 to appear in the J. Mag. Mag. Mat Revised versio