Effectiveness of antiplatelet therapy in atherosclerotic disease: comparing the ASA low-response prevalence in CVD,CAD and PAD

Although acetylsalicylic acid (ASA, aspirin) reduces the risk of ischemic events in patients with atherosclerosis, a substantial number of incidents continue to occur. As only limited data exist we evaluated the antiplatelet effectiveness of ASA in patients with different manifestations of atherosclerosis as in cerebrovascular, coronary artery and peripheral arterial disease (CVD, CAD, PAD). For the evaluation of the antiplatelet effectiveness of ASA we used whole blood aggregometry (Chrono-log Model 590). The patients in the different subgroups received ASA 100, 200 or 500 mg daily. We analysed 737 consecutive patients: 47.5 % with CVD, 33.6 % with CAD, and 18.9 % with PAD. We identified 28.0 % of the CVD, 18.1 % of the CAD and 21.6 % of the PAD patients to be ASA low-responder (ALR). Comparing subgroups treated with 100 mg ASA, 36.4 % were ALR in the CVD group as were 13.1 % of the CAD and 21.6 % of the PAD patients. Multivariate regression analysis revealed an odds ratio for being ALR of 4.50 (95 % confidence interval (CI) 1.70–11.9) when 100 mg and of 2.97 (95 % CI 1.58–5.60) when 200 mg ASA was taken compared to a dose of 500 mg. Despite the proven benefits of antiplatelet therapy in the secondary prevention of atherosclerotic disease, current antiplatelet management is suboptimal as up to 36 % of patients failed to achieve an adequate platelet inhibitory effect. Our findings may explain, at least in part, the high rates of cardiovascular events observed in the course of atherothrombotic disease and support the need to improve antiplatelet therapy.     

Osteomyelitis due to multiple carbapenemase-producing Gram-negative bacteria: The first case report of a GES-13-producing Pseudomonas aeruginosa isolate in Canada

A case of osteomyelitis in an infant following a burn injury sustained in Pakistan caused by a GES-13-producing Pseudomonas aeruginosa (the first reported in Canada) and an OXA-48 producing Klebsiella pneumoniae is described. The present case serves to highlight the importance of international travel as a risk factor for infection with carbapenemase-producing bacteria and the challenges in the laboratory detection of these organisms.     

Random Forest-Based Bone Segmentation in Ultrasound

Ultrasound (US) imaging is a safe alternative to radiography for guidance during minimally invasive orthopedic procedures. However, ultrasound is challenging to interpret because of the relatively low signal-to-noise ratio and its inherent speckle pattern that decreases image quality. Here we describe a method for automatic bone segmentation in 2-D ultrasound images using a patch-based random forest classifier and several ultrasound specific features, such as shadowing. We illustrate that existing shadow features are not robust to changes in US acquisition parameters, and propose a novel robust shadow feature. We evaluate the method on several US data sets and report that it favorably compares with existing techniques. We achieve a recall of 0.86 at a precision of 0.82 on a test set of 143 spinal US images.     

A test of the chromosomal theory of ecotypic speciation in Anopheles gambiae

The role of chromosomal inversions in speciation has long been of interest to evolutionists. Recent quantitative modeling has stimulated reconsideration of previous conceptual models for chromosomal speciation. Anopheles gambiae, the most important vector of human malaria, carries abundant chromosomal inversion polymorphism nonrandomly associated with ecotypes that mate assortatively. Here, we consider the potential role of paracentric inversions in promoting speciation in A. gambiae via "ecotypification," a term that refers to differentiation arising from local adaptation. In particular, we focus on the Bamako form, an ecotype characterized by low inversion polymorphism and fixation of an inversion, 2Rj, that is very rare or absent in all other forms of A. gambiae. The Bamako form has a restricted distribution by the upper Niger River and its tributaries that is associated with a distinctive type of larval habitat, laterite rock pools, hypothesized to be its optimal breeding site. We first present computer simulations to investigate whether the population dynamics of A. gambiae are consistent with chromosomal speciation by ecotypification. The models are parameterized using field observations on the various forms of A. gambiae that exist in Mali, West Africa. We then report on the distribution of larvae of this species collected from rock pools and more characteristic breeding sites nearby. Both the simulations and field observations support the thesis that speciation by ecotypification is occurring, or has occurred, prompting consideration of Bamako as an independent species.     

The effect of glucosamine and/or chondroitin sulfate on the progression of knee osteoarthritis: a report from the glucosamine/chondroitin arthritis intervention trial

OBJECTIVE: Osteoarthritis (OA) of the knee causes significant morbidity and current medical treatment is limited to symptom relief, while therapies able to slow structural damage remain elusive. This study was undertaken to evaluate the effect of glucosamine and chondroitin sulfate (CS), alone or in combination, as well as celecoxib and placebo on progressive loss of joint space width (JSW) in patients with knee OA. METHODS: A 24-month, double-blind, placebo-controlled study, conducted at 9 sites in the United States as part of the Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT), enrolled 572 patients with knee OA who satisfied radiographic criteria (Kellgren/Lawrence [K/L] grade 2 or grade 3 changes and JSW of at least 2 mm at baseline). Patients with primarily lateral compartment narrowing at any time point were excluded. Patients who had been randomized to 1 of the 5 groups in the GAIT continued to receive glucosamine 500 mg 3 times daily, CS 400 mg 3 times daily, the combination of glucosamine and CS, celecoxib 200 mg daily, or placebo over 24 months. The minimum medial tibiofemoral JSW was measured at baseline, 12 months, and 24 months. The primary outcome measure was the mean change in JSW from baseline. RESULTS: The mean JSW loss at 2 years in knees with OA in the placebo group, adjusted for design and clinical factors, was 0.166 mm. No statistically significant difference in mean JSW loss was observed in any treatment group compared with the placebo group. Treatment effects on K/L grade 2 knees, but not on K/L grade 3 knees, showed a trend toward improvement relative to the placebo group. The power of the study was diminished by the limited sample size, variance of JSW measurement, and a smaller than expected loss in JSW. CONCLUSION: At 2 years, no treatment achieved a predefined threshold of clinically important difference in JSW loss as compared with placebo. However, knees with K/L grade 2 radiographic OA appeared to have the greatest potential for modification by these treatments.