Accuracy of ultrasound in counting and measuring gallstones

A prospective study of accuracy of ultrasound in measuring and counting gallstones was undertaken in 30 patients undergoing cholecystectomy. Stones were correctly counted (up to five) in 27 of 30 patients. Ninety-three of 106 stones (88%) examined were measured accurately (with a 2 mm error margin). The size of the smaller stones tended to be overestimated, whereas the size of the larger stones tended to be underestimated. When non-operative treatment of gallstones is considered, ultrasound can be used as the first examination to identify patients who will not be eligible for one or another protocol on the basis of size or number of stones.     

Gas bubble emboli detected by transcranial Doppler sonography in patients with prosthetic heart valves: a preliminary report.

After observing spikes in the Doppler signal of cerebral arteries of patients with neurologic symptoms and prosthetic heart valves, we then studied two groups of patients with prosthetic heart valves: seven patients with neurologic symptoms and 65 asymptomatic patients. Using transcranial Doppler sonography of the middle cerebral artery, we found Doppler spikes in six symptomatic and 24 asymptomatic patients with mechanical heart valves. No spikes were found in one symptomatic and 21 asymptomatic patients with biological valves or in 20 asymptomatic patients with mechanical valves. We concluded that gas cavitation during the opening or closure of the valve, producing bubble emboli, is the most probable explanation for these Doppler spikes in patients with mechanical prosthetic heart valves.     

Cortical involvement in acquisition and extinction of trace eyeblink conditioning

Previous studies have implicated 2 cortical regions interconnected with the hippocampal formation, the retrosplenial cortex (RSC) and the medial prefrontal cortex (mPFC), as loci important for the acquisition of hippocampally dependent trace eyeblink conditioning. These loci have also been proposed to serve as long-term storage sites of task critical information. This study used lesions made prior to training to investigate the roles of the RSC, as well as the caudal and rostral subdivisions of the mPFC, in the acquisition and subsequent extinction of trace eyeblink conditioning in the rabbit. The caudal mPFC and rostral mPFC were shown to be critical for acquisition and extinction of the conditioned reflex, respectively. The data indicate that the RSC is not critical for acquisition or extinction of the trace conditioned reflex.     

The burden of natural and technological disaster-related mortality on gross domestic product (GDP) in the WHO African region

The WHO Africa region has the highest disaster mortality rate compared to the other five regions of the organization. Those deaths are hypothesized to have significantly negative effect on per capita gross domestic product (GDP). The objective of this study was to estimate the loss in GDP attributable to natural and technological disaster-related mortality in the WHO African Region. We estimated the impact of disaster-related mortality on GDP using double-log econometric model and cross-sectional data (from the UNDP and the World Bank publications) on 45 out of 46 countries in the WHO African Region. The coefficients for capital (K), educational enrolment (EN), life expectancy (LE) and exports (X) had a positive sign; while imports (M) and disaster mortality (DS) were found to impact negatively on GDP. The abovementioned explanatory variables were found to have statistically significant effect on GDP at 5% level in a t-distribution test. Disaster mortality of a single person was found to reduce GDP by US$0.018. We have demonstrated that disaster mortality has a significant negative effect on GDP. Thus, as policy-makers strive to increase GDP through capital investment, export promotion and increase in educational enrolment, they should always recall that investments in strengthening national capacity to mitigate the effects of national disasters expeditiously and effectively shall yield significant economic returns.     

Pancreatic calcifications associate with diverse aetiological risk factors in patients with chronic pancreatitis: A multicentre study of 1500 cases

BackgroundPancreatic calcifications is a common finding in patients with chronic pancreatitis (CP), but the underlying pathophysiology is incompletely understood. Past studies for risk factors of calcifications have generally been focused on single parameters or limited by small sample sizes. The aim of this study was to explore several patient and disease characteristics and their associations with pancreatic calcifications in a large cohort of CP patients with diverse aetiological risk factors.MethodsThis was a multicentre, cross-sectional study including 1509 patients with CP. Patient and disease characteristics were compared for patients with calcifications (n = 912) vs. without calcifications (n = 597). Multivariable logistic regression was performed to assess the parameters independently associated with calcifications.ResultsThe mean age of patients was 53.9 ± 14.5 years and 1006 (67%) were men. The prevalence of calcifications was 60.4% in the overall patient cohort, but highly variable between patients with different aetiological risk factors (range: 2–69%). On multivariate analysis, alcoholic aetiology (OR 1.76 [95% CI, 1.39–2.24]; p < 0.001) and smoking aetiology (OR 1.77 [95% CI, 1.39–2.26], p < 0.001) were positively associated with the presence of calcifications, while an autoimmune aetiology was negatively associated with calcifications (OR 0.15 [95% CI, 0.08–0.27], p < 0.001). Patients with pancreatic calcifications were more likely to have undergone pancreatic duct stenting (OR 1.59 [95%CI, 1.16–2.19], p = 0.004).ConclusionThe presence of pancreatic calcifications is associated with diverse aetiological risk factors in patients with CP. This observation attest to the understanding of CP as a complex disease and may have implications for disease classification.     

Evaluation of Down's syndrome screening population data sets by simulation: analyser-specific parameters may be superior to meta-analysis-derived parameters

Objective: Choice of parameter sets used to calculate Down's syndrome risks is complicated. Published population statistics were compared with assay‐specific parameters to optimise screening efficiency. Design: Weight‐corrected Gaussian population statistics for α‐fetoprotein (AFP), human chorionic gonadotropin (HCG) and unconjugated oestriol (uE₃), expressed as log₁₀ multiples of median (MoM) were established for a Belgian cohort of 748 unaffected pregnancies. Using Cuckle's method and Access^®‐specific data, Down's syndrome parameters were tailored to the Belgian cohort. Correlated marker triplets for affected and unaffected pregnancies were modelled and combined with maternal age to calculate term risks for Trisomy 21. Receiver‐Operator‐Curve (ROC) analysis was performed to identify the optimally‐performing population set. Results: Log‐normal distributions for the Access^® markers had geometric mean MoM values close to zero and standard deviation values equal to 0.1460 (AFP), 0.2185 (HCG) and 0.1317 (uE₃). Correlation between AFP and other markers was significant (p < 0.001). Correlation between HCG and uE₃ was not significant (p = 0.4818). The median ratio between the lowest and highest risk outcomes for the test MoM set was 4.3. Areas under ROC curves differed significantly (p < 0.001) between the models and the analyser‐assay specific parameters resulted in the largest area. At a 1 in 250 threshold, sensitivity and specificity were 69% and 96%. At false‐positive rates (1‐specificity) = 5%, sensitivity was 72.5%. Conclusion: Population parameters significantly affect risk outcome and hence screening performance. Highest efficiency may be obtained with parameters tailored to an assay‐specific population model. Consequently models from literature, without knowledge of the assay/analyser combination may lead to suboptimal performance.     

Falsely high serum drug concentrations caused by blood samples from contaminated fingers

A high serum digoxin concentration (8.9 nmol/L) was recorded in a child suspected of swallowing digoxin tablets (Lanoxin PG 62.5 micrograms). The finger-prick blood sample was taken approximately 3.5 h postingestion. The child remained asymptomatic, and subsequent samples taken 5.5 and 23 h postingestion revealed zero digoxin concentrations. It was postulated that the initial blood sample may have been taken from a finger that was contaminated with digoxin from handling the tablets. To test this hypothesis, blood samples were taken from fingers of volunteers after handling various tablets, including digoxin, carbamazepine, paracetamol, and theophylline. Apparently, toxic digoxin concentrations were found for all volunteers handling digoxin tablets, though no volunteers were taking digoxin. Swabbing or not swabbing the finger with alcohol made minimal difference. Finger-prick samples from volunteers handling other tablets revealed falsely high and often "toxic" concentrations of the respective drugs, although values varied markedly. Caution should be exercised by those taking finger-prick blood samples, or interpreting drug concentrations from these samples, if the patient may have handled the tablets prior to the sample being taken.     

Health security as a public health concept: a critical analysis

There is growing acceptance of the concept of health security. However, there are various and incompatible definitions, incomplete elaboration of the concept of health security in public health operational terms, and insufficient reconciliation of the health security concept with community-based primary health care. More important, there are major differences in understanding and use of the concept in different settings. Policymakers in industrialized countries emphasize protection of their populations especially against external threats, for example terrorism and pandemics; while health workers and policymakers in developing countries and within the United Nations system understand the term in a broader public health context. Indeed, the concept is used inconsistently within the UN agencies themselves, for example the World Health Organization's restrictive use of the term 'global health security'. Divergent understandings of 'health security' by WHO's member states, coupled with fears of hidden national security agendas, are leading to a breakdown of mechanisms for global cooperation such as the International Health Regulations. Some developing countries are beginning to doubt that internationally shared health surveillance data is used in their best interests. Resolution of these incompatible understandings is a global priority.