Validation of a method for determination of the ankle-brachial index in the seated position

ObjectiveTo validate a method for determination of the ankle-brachial index (ABI) in the seated position.BackgroundPeripheral arterial disease (PAD) is a prevalent disorder that is associated with quality of life impairment and increased risk of a major cardiovascular event. The ABI is the initial test for screening and diagnosis of PAD. To prevent error due hydrostatic pressure, accurate measurement of the ABI requires supine patient positioning. Access to ABI measurement is limited for patients who are immobilized or unable to lie flat.MethodsPatients presenting to a vascular laboratory for suspected arterial disease were enrolled. Arm and ankle blood pressures were measured in the supine and seated positions. Seated ankle pressures were corrected by the following physiology-based formula: Corrected ankle pressure = Measured ankle pressure – D*(.078), where D = the vertical distance between the arm and ankle cuffs (mm). This formula equates to a correction factor of 78 mm Hg per meter distance between the arm and ankle cuffs. Corrected ankle pressure measurements were used for seated ABI calculation.ResultsComplete data were available for 100 patients. Mean ABI was 0.97, and 31% of patients had an ABI ≤0.9. There was excellent correlation between supine and corrected seated ankle pressure measurements (r = 0.884-0.936, P < .001). The difference between measurements was negligible (<5 mm Hg). Similarly, there was excellent correlation between supine and seated ABI measures (r = 0.936, P < .001). There was no significant difference between the supine and seated ABI measures.ConclusionWe have developed and validated a method for determination of the ABI in the seated position which can be used to broaden availability of PAD testing. This method could also be incorporated into new technologies for ABI determination in the seated position

Loop-mediated isothermal amplification for diagnosis of 18 World Organization for Animal Health (OIE) notifiable viral diseases of ruminants, swine and poultry

AbstractLoop-mediated isothermal amplification (LAMP) is a simple, powerful state-of-the-art gene amplification technique used for the rapid diagnosis and early detection of microbial diseases. Many LAMP assays have been developed and validated for important epizootic diseases of livestock. We review the LAMP assays that have been developed for the detection of 18 viruses deemed notifiable of ruminants, swine and poultry by the World Organization for Animal Health (OIE). LAMP provides a fast (the assay often takes less than an hour), low cost, highly sensitive, highly specific and less laborious alternative to detect infectious disease agents. The LAMP procedure can be completed under isothermal conditions so thermocyclers are not needed. The ease of use of the LAMP assay allows adaptability to field conditions and works well in developing countries with resource-limited laboratories. However, this technology is still underutilized in the field of veterinary diagnostics despite its huge capabilities.</jats:p

Subclavian Artery Stenosis: Prevalence, Risk Factors, and Association With Cardiovascular Diseases

ObjectivesThe objective was to assess the prevalence of subclavian artery stenosis (SS) in four cohorts (two free-living and two clinical populations) and determine both risk factors for this condition and the association with other cardiovascular conditions.BackgroundThe prevalence of SS in the general population is unknown, and its association with risk factors and other cardiovascular diseases is not well-established.MethodsA total of 4,223 subjects (2,975 from two free-living cohorts and 1,248 from two clinical cohorts) were included in this cross-sectional analysis. Subclavian artery stenosis was defined as ≥15 mm Hg interarm pressure difference.ResultsThe prevalence of SS was 1.9% in the free-living cohorts and 7.1% in the clinical cohorts; SS was significantly (p < 0.05) associated with past smoking (odds ratio [OR] = 1.80), current smoking (OR = 2.61), and higher levels of systolic blood pressure (OR = 1.90 per 20 mm Hg). Higher levels of high-density lipoprotein (HDL) cholesterol were inversely and significantly associated with SS (OR = 0.87 per 10 mg/dl). In regression analyses relating SS to other cardiovascular diseases, the only significant finding was with peripheral arterial disease (PAD) (OR = 5.11, p < 0.001).ConclusionsSignificant SS is present in approximately 2% of the free-living population and 7% of the clinical population. Additionally, SS is correlated with current and past smoking histories, systolic blood pressure, HDL levels (inversely), and the presence of PAD. These findings suggest that bilateral brachial blood pressure measurements should routinely be performed in patients with an elevated risk profile, both to screen for SS, and to avoid missing a hypertension or PAD diagnosis because of unilateral pressure measurement in an obstructed arm