Low-cost tools for diagnosing and monitoring HIV infection in low-resource settings

Low-cost technologies to diagnose and monitor human immunodeficiency virus (HIV) infection in developing countries are a major subject of current research and health care in the developing world. With the great need to increase access to affordable HIV monitoring services in rural areas of developing countries, much work has been focus on the development of point-of-care technologies that are affordable, robust, easy to use, portable and of sufficient quantitative accuracy to enable clinical decision-making. For diagnosis of HIV infection, some low-cost tests, such as lateral flow tests and enzyme-linked immunosorbent assays, are already in place and well established. However, portable quantitative tests for rapid HIV monitoring at the point of care have only recently been introduced to the market. In this review, we discuss low-cost tests for HIV diagnosis and monitoring in low-resource settings, including promising technologies for use at the point of care, that are available or close to market.     

Subclavian stenting in a hostile aortic arch facilitated by a low-profile brachial artery through-and-through access

Subclavian stenting can be extremely difficult in a hostile type II aortic arch (with acute angulation of the subclavian artery origin) or type III aortic arch. This case illustrates use of a low-profile system to gain through-and-through (flossing) access through the brachial artery to facilitate stenting via the femoral approach. This approach can be useful in patients with small brachial arteries where the risk of complication may be high if a standard vascular sheath was placed for stenting via the brachial approach. This technique also avoids the use of a surgical cut down.     

Impact of UK National Guidelines based on FRAX®– comparison with current clinical practice

Objective To assess whether clinician‐determined treatment intervention thresholds are in line with the assessment of fracture risk provided by FRAX^® and treatment recommendations provided by UK guidelines produced by the National Osteoporosis Guidelines Group (NOGG). Design, Patients and Measurements This was a retrospective cohort analysis of 288 patients consecutively referred for dual‐energy X‐ray absorptiometry (DXA) scanning from primary care immediately prior to the introduction of the FRAX^® algorithm. In addition to DXA assessment, patients completed a clinical risk factor questionnaire which included risk factors used in the FRAX^® algorithm. Initial risk assessment and treatment decisions were performed after DXA. FRAX^® was used, retrospectively, with femoral neck T‐score, to estimate fracture risk which was applied to NOGG to generate guidance on treatment intervention. Clinician‐ and NOGG‐determined outcomes were audited for concordance. Results There was concordance between clinician and NOGG treatment decisions in 215 (74·6%) subjects. Discordance was observed in 73 (25·3%) subjects. In the discordant group, seven subjects were given lifestyle advice when NOGG recommended treatment, 42 given treatment when NOGG recommended lifestyle advice only, and 24 were referred to a metabolic bone clinic for further evaluation. The reasons for treatment differences in subjects recommended treatment by clinician but not NOGG were largely (90·2%) attributed to the use of lumbar spine bone mineral density (BMD). Conclusions There is high concordance between clinician‐determined and FRAX^®‐NOGG intervention. The absence of spine BMD from FRAX^® is the primary source of discrepancy. This study provides some assurance of the validity of the treatment thresholds generated from FRAX^®‐NOGG in ‘real‐world’ usage.     

Platelet reactivity in patients and recurrent events post-stenting: results of the PREPARE POST-STENTING Study.

OBJECTIVES: We investigated the relation of high ex vivo platelet reactivity, rapid fibrin generation, and high thrombin-induced clot strength to postdischarge ischemic events in patients undergoing percutaneous coronary intervention (PCI). BACKGROUND: High platelet reactivity and rapid fibrin generation may affect the incidence of ischemic events after PCI. However, limited data is available to link these ex vivo markers to the occurrence of events. METHODS: We measured platelet reactivity to adenosine diphosphate (ADP) by light transmittance aggregometry (LTA) in patients undergoing PCI (n = 192). Clot strength, a measure of thrombin-induced fibrin and platelet interactions, and the time to initial fibrin generation, a marker of thrombin activity, were measured by thrombelastography. The relation of these measurements to ischemic event occurrence was prospectively examined over six months. RESULTS: A total of 100% and 84% of patients were on aspirin and clopidogrel therapy, respectively, at the time of the initial event. Posttreatment ADP-induced aggregation by LTA (63 +/- 12% vs. 56 +/- 15%, p = 0.02) and clot strength (MA) were higher (74 +/- 5 mm vs. 65 +/- 4 mm, p < 0.001) and time to initial fibrin generation was shorter (4.3 +/- 1.3 min vs. 5.9 +/- 1.5 min, p < 0.001) in patients with events (n = 38). The event rates in the highest quartiles of LTA and MA were 32% and 58%, respectively. CONCLUSIONS: High platelet reactivity and clot strength, and rapid fibrin formation are novel risk factors for ischemic events after PCI. Clot strength is more predictive than ADP-induced platelet aggregation and may explain the occurrence of events despite treatment with cyclooxygenase-1 and P2Y12 inhibitors.     

Irritable bowel syndrome: in search of an etiology: role of Blastocystis hominis

This study was designed to examine stool specimens of irritable bowel syndrome (IBS) patients for Blastocystis hominis, a common intestinal parasite. One hundred fifty patients were enrolled, 95 IBS cases and 55 controls. These patients provided a medical history, and underwent physical and laboratory evaluations that included stool microscopy and culture for B. hominis and colonoscopy. The 95 cases (51 males and 44 females) had a mean +/- SD age of 37.8 +/- 13.2 years. Stool microscopy was positive for B. hominis in 32% (30 of 95) of the cases and 7% (4 of 55) of the controls (P = 0.001). Stool culture was positive in 46% (44 of 95) of the cases and 7% (4 of 55) of the controls (P < 0.001). Stool culture for B. hominis in IBS was more sensitive than microscopy (P < 0.001). Blastocystis hominis was frequently demonstrated in the stool samples of IBS patients; however, its significance in IBS still needs to be investigated. Stool culture has a higher positive yield for B. hominis than stool microscopy.