Quantitative measurement of lead in paint by XRF analysis without manual substrate correction

X-ray fluorescence analysis has been used for measurement of lead in paint for more than a decade. The early systems provided a nondestructive alternative technology to laboratory-based technologies, but were somewhat time consuming and often led to inconclusive results. The procedure required manual substrate correction, multiple measurements, operator's discretion in validating a measurement due to interfering elements and laboratory analysis of inconclusive samples. A new instrument, the RMD LPA-1 system, has been developed based on X-ray fluorescence technology that addresses all of the drawbacks to the older systems. This new system uses a carefully designed and controlled geometry and modern microprocessor technology to automatically provide a rapid quantitative measurement of lead in paint with a 95% confidence level. The improved precision and accuracy achieved with this system are due to geometric enhancements and a mathematical approach which incorporates corrections for both random and systematic errors such as matrix effects and Compton scatter. This technology has been incorporated in a hand-held X-ray fluorescence lead paint analyzer system. A key design philosophy for this system was to maintain a very narrow, task-specific focus, the system was not designed to be an all purpose XRF analyzer, rather it is optimized to meet regulatory requirements of lead paint testing in the most efficient manner. The development of the LPA-1 system is an example of what can be accomplished by listening to the needs and desires of the users, rethinking the design of an existing technique and incorporating modern microprocessor technology.     

Bench-to-bedside review: Rapid molecular diagnostics for bloodstream infection - a new frontier?

ABSTRACT: Among critically ill patients, the diagnosis of bloodstream infection poses a major challenge. Current standard bacterial identification based on blood culture platforms is intrinsically time-consuming and slow. The continuous evolvement of molecular techniques has the potential of providing a faster, more sensitive and direct identification of causative pathogens without prior need for cultivation. This may ultimately impact clinical decision-making and antimicrobial treatment. This review summarises the currently available technologies, their strengths and limitations and the obstacles that have to be overcome in order to develop a satisfactory bedside point-of-care diagnostic tool for detection of bloodstream infection.     

3T multiparametric MR imaging,PIRADSv2-based detection of index prostate cancer lesions in the transition zone and the peripheral zone using whole mount histopathology as reference standard

Abdominal Radiology - To evaluate 3T mpMRI characteristics of transition zone and peripheral zone index prostate cancer lesions stratified by Gleason Score and PI-RADSv2 with whole mount...     

Disease Expression and Familial Transmission of Fuchs Endothelial Corneal Dystrophy With and Without CTG18.1 Expansion

PurposeTo characterize inheritance, penetrance, and trinucleotide repeat expansion stability in Fuchs endothelial corneal dystrophy (FECD).MethodsOne thousand unrelated and related subjects with and without FECD were prospectively recruited. CTG18.1 repeat length (CTG18.1_L) was determined via short tandem repeat assay and Southern blotting of leukocyte DNA. Multivariable logistic regression and generalized estimating equation models were employed.ResultsThere were 546 unrelated FECD cases (67.6% female; 70 ± 10 years) and 235 controls (63.8% female; 73 ± 8 years; all ≥ 50 years). CTG18.1 expansion (CTG18.1exp+) was observed in 424 (77.7%) cases and 18 (7.7%) controls (P = 2.48 × 10^–44). CTG18.1 expansion was associated with FECD severity (P = 5.62 × 10^–7). The family arm of the study included 331 members from 112 FECD-affected families; 87 families were CTG18.1exp+. Autosomal dominant inheritance with variable expression of FECD was observed, regardless of expansion status. FECD penetrance of CTG18.1 expansion increased with age, ranging from 44.4% in the youngest (19–46 years) to 86.2% in the oldest (64–91 years) age quartiles. Among 62 parent–offspring transmissions of CTG18.1exp+, 48 (77.4%) had a change in CTG18.1_L ≤ 10 repeats, and eight (12.9%) were ≥50 repeats, including five large expansions (∼1000–2000 repeats) that contracted. Among 44 offspring who did not inherit the CTG18.1exp+ allele, eight (18.2%) exhibited FECD.ConclusionsCTG18.1 expansion was highly associated with FECD but demonstrated incomplete penetrance. CTG18.1_L instability occurred in a minority of parent–offspring transmissions, with large expansions exhibiting contraction. The observation of FECD without CTG18.1 expansion among family members in CTG18.1exp+ families highlights the complexity of the relationship between the FECD phenotype and CTG18.1 expansion.     

Efficacy analysis of hydroxychloroquine therapy in systemic lupus erythematosus: a study on disease activity and immunological biomarkers

Background

Hydroxychloroquine (HCQ) is a widely prescribed medication to patients with systemic lupus erythematosus (SLE), with potential anti-inflammatory effects. This study was performed to investigate the efficacy of HCQ therapy by serial assessment of disease activity and serum levels of proinflammatory cytokines in SLE patients.

Methods

In this prospective cohort study, 41 newly diagnosed SLE patients receiving 400 mg HCQ per day were included. Patients requiring statins and immunosuppressive drugs except prednisolone at doses lower than 10 mg/day were excluded. Outcome measures were assessed before commencement of HCQ therapy (baseline visit) as well as in two follow-up visits (1 and 2 months after beginning the HCQ therapy). Serum samples of 41 age-matched healthy donors were used as controls.

Results

Median levels of IL-1β (p?<?0.001), IL-6 (p?=?0.001), and TNF-α (p?<?0.001) were significantly higher, whereas, median CH50 level was significantly lower (p?<?0.001) in SLE patients compared with controls. Two-month treatment with HCQ resulted in significant decrease in SLEDAI-2K (p?<?0.001), anti-dsDNA (p?<?0.001), IL-1β (p?=?0.003), IL-6 (p?<?0.001) and TNF-α (p?<?0.001) and a significant increase in CH50 levels (p?=?0.012). The reductions in SLEDAI-2K and serum levels of IL-1β and TNF-α were significantly greater in the first month compared with the reductions in the second month.

Conclusion

HCQ therapy is effective on clinical improvement of SLE patients through interfering with inflammatory signaling pathways, reducing anti-DNA autoantibodies and normalizing the complement activity.