28,247 research outputs found
Alternative antibody for the detection of CA125 antigen: a European multicenter study for the evaluation of the analytical and clinical performance of the Access (R) OV Monitor assay on the UniCel (R) Dxl 800 Immunoassay System
Background: Cancer antigen CA125 is known as a valuable marker for the management of ovarian cancer. Methods: The analytical and clinical performance of the Access OV Monitor Immunoassay System (Beckman Coulter) was evaluated at five different European sites and compared with a reference system, defined as CA125 on the Elecsys System (Roche Diagnostics). Results: Total imprecision (%CV) of the OV Monitor ranged between 3.1% and 8.8%, and inter-laboratory reproducibility between 4.7% and 5.0%. Linearity upon dilution showed a mean recovery of 100% (SD+8.1%). Endogenous interferents had no influence on OV Monitor levels (mean recoveries: hemoglobin 107%, bilirubin 103%, triglycericles 103%). There was no high-dose hook effect up to 27,193 kU/L. Clinical performance investigated in sera from 1811 individuals showed a good correlation between the Access OV Monitor and Elecsys CA125 (R = 0.982, slope = 0.921, intercept = + 1.951). OV Monitor serum levels were low in healthy individuals (n = 267, median = 9.7 kU/L, 95th percentile = 30.8 kU/L), higher in individuals with various benign diseases (n = 549, medians = 10.9-16.4 kU/L, 95th percentiles = 44.2-355 kU/L) and even higher in individuals suffering from various cancers (n = 995, medians= 12.4-445 kU/L; 95th percentiles = 53.4-4664 kU/L). Optimal diagnostic accuracy for cancer detection against the relevant benign control group by the OV Monitor was found for ovarian cancer {[}area under the curve (AUC) 0.898]. Results for the reference CA125 assay were comparable (AUC 0.899). Conclusions: The Access OV Monitor provides very good methodological characteristics and demonstrates an excellent analytical and clinical correlation with Elecsys CA125. The best diagnostic accuracy for the OV Monitor was found in ovarian cancer. Our results also suggest a clinical value of the OV Monitor in other cancers
Metformin, Sulfonylureas, or Other Antidiabetes Drugs and the Risk of Lactic Acidosis or Hypoglycemia
OBJECTIVE: Lactic acidosis has been associated with use of metformin. Hypoglycemia is a major concern using sulfonylureas. The aim of this study was to compare the risk of lactic acidosis and hypoglycemia among patients with type 2 diabetes using oral antidiabetes drugs. RESEARCH DESIGN AND METHODS: This study is a nested case-control analysis using the U.K.-based General Practice Research Database to identify patients with type 2 diabetes who used oral antidiabetes drugs. Within the study population, all incident cases of lactic acidosis and hypoglycemia were identified, and hypoglycemia case subjects were matched to up to four control patients based on age, sex, practice, and calendar time. RESULTS: Among the study population of 50,048 type 2 diabetic subjects, six cases of lactic acidosis during current use of oral antidiabetes drugs were identified, yielding a crude incidence rate of 3.3 cases per 100,000 person-years among metformin users and 4.8 cases per 100,000 person-years among users of sulfonylureas. Relevant comorbidities known as risk factors for lactic acidosis could be identified in all case subjects. A total of 2,025 case subjects with hypoglycemia and 7,278 matched control subjects were identified. Use of sulfonylureas was associated with a materially elevated risk of hypoglycemia. The adjusted odds ratio for current use of sulfonylureas was 2.79 (95% CI 2.23–3.50) compared with current metformin use. CONCLUSIONS: Lactic acidosis during current use of oral antidiabetes drugs was very rare and was associated with concurrent comorbidity. Hypoglycemic episodes were substantially more common among sulfonylurea users than among users of metformin.Merck SA, Lyon, Franc
Use of depot medroxyprogesterone acetate and fracture risk
Depot medroxyprogesterone acetate (DMPA), which has a high rate of use among teenagers in Europe and the United States, has been associated with impaired bone mineral acquisition during adolescence and accelerated bone loss in later life. Studies on the association between DMPA use and fracture risk are limited.; We aimed at evaluating the relationship between use of hormonal contraceptives, specifically DMPA, and fracture risk.; We conducted a case-control analysis using the United Kingdom-based General Practice Research Database.; Participants were females aged 20-44 yr with an incident fracture diagnosis between 1995 and 2008.; Odds ratios (OR) with 95% confidence intervals (CI) of incident fracture in relation to exposure to DMPA or combined oral contraceptives were assessed. Adjustments were made for smoking, body mass index, and additional potential confounders.; We identified 17,527 incident fracture cases and 70,130 control patients (DMPA exposure: 11 and 8%, respectively). Compared with nonuse, current use of one to two, three to nine, or 10 or more DMPA prescriptions yielded adjusted OR for fractures of 1.18 (95% CI = 0.93-1.49), 1.36 (95% CI = 1.15-1.60), and 1.54 (95% CI = 1.33-1.78), respectively. Fracture risk was highest after longer treatment duration (<2-3 yr), and there was no difference in patients below and above the age of 30 yr. For users of combined estrogen-containing oral contraceptives, the OR were around 1.; This population-based study suggests that use of DMPA is associated with a slightly increased risk of fractures
Monadicity of the Bousfield-Kuhn functor
We consider the localization of the -category of spaces at the -periodic equivalences, the case being rational homotopy theory. We prove that this localization is for equivalent to algebras over a certain monad on the -category of -local spectra. This monad is built from the Bousfield--Kuhn functor
Tunneling induced electron transfer between separated protons
We study electron transfer between two separated nuclei using local control
theory. By conditioning the algorithm in a symmetric system formed by two
protons, one can favored slow transfer processes, where tunneling is the main
mechanism, achieving transfer efficiencies close to unity assuming fixed
nuclei. The solution can be parametrized using sequences of pump and dump pi
pulses, where the pump pulse is used to excite the electron to a highly excited
state where the time for tunneling to the target nuclei is on the order of
femtoseconds. The time delay must be chosen to allow for full population
transfer via tunneling, and the dump pulse is chosen to remove energy from the
state to avoid tunneling back to the original proton. Finally, we study the
effect of the nuclear kinetic energy on the transfer efficiency. Even in the
absence of relative motion between the protons, the spreading of the nuclear
wave function is enough to reduce the yield of electronic transfer to less than
one half.Comment: 7 pages, 8 figure
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