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Selected AbstractsConcentrate safety and efficacyHAEMOPHILIA, Issue 3 2002C. K. KASPER Safety from transmission of infections through plasma-derived clotting factor concentrates is assured by improved donor screening, serological testing of individual donations and direct viral testing of small plasma pools. Modern viral-inactivation techniques are highly effective. Recombinant concentrates stabilized in human albumin are being superaeded by those with other stabilizers. Recently reported discrepancies between estimates of concentrate potency from in vitro assays versus in vivo recovery, depending upon type of assay and reference standard used, are not fully resolved. [source] Assessment of fibrosis in chronic liver diseasesJOURNAL OF DIGESTIVE DISEASES, Issue 1 2009Kun ZHOU The assessment of liver fibrosis provides useful information not only for diagnosis but also for therapeutic decisions. Although liver biopsy is the current gold standard for fibrosis assessment, it has some risks and limitations, including intra-observer and inter-observer variation, sampling error and variability. In recent years, many studies and great interest have been dedicated to the development of non-invasive tests to substitute a liver biopsy for fibrosis assessment and follow up. Advances in serological and radiological tests such as serum marker panels, transient elastography and their combinations can assess fibrosis accurately and reduce the need for a liver biopsy. But at present, all have failed to completely replace a liver biopsy because of their respective limitations and an imperfect gold standard used in current researches. The searching for an ideal surrogate is still in progress. [source] Risk of malnutrition in a sample of acute and long-stay NHS Fife in-patients: an auditJOURNAL OF HUMAN NUTRITION & DIETETICS, Issue 1 2008C. H. S. Ruxton Abstract Background, Hospital malnutrition (undernutrition) continues to attract concern. The implementation of standards for food and fluids in Scotland provided the stimulus for an audit of current practices in NHS Fife hospitals in order to provide baseline data with which to evaluate progress. Methods, One hundred and fifty in-patients were recruited from wards likely to yield those with a high risk of malnutrition. Using patient records and anthropometry, data were collected on weight, weight change, body mass index (BMI), mid-upper-arm circumference (MUAC), dietetic referral, therapeutic diets and patients' perceptions of nutritional status. Malnutrition was estimated by comparing BMI, weight change and MUAC with the Malnutrition Universal Screening Tool (MUST) and standards published by the Scottish Intercollegiate Guidelines Network (SIGN). Results, Depending upon the standard used, the minimum risk of malnutrition varied from 14 to 25%. The prevalence was lower than that reported previously, although methods were not directly comparable. Obesity was also evident with 42% of patients having a BMI > 25. Mean weight change from admission to audit was +0.4 kg, with a wide range (,11 kg to +13 kg). Most patients identified as malnourished were referred to the dietitian or given nutritional support. Conclusions, Fewer patients were at risk of malnutrition than expected. However, improving the provision of food and fluids remains a priority in Fife as malnutrition and eating problems can occur across the entire BMI spectrum. [source] A multicenter pharmacokinetic study of the B-domain deleted recombinant factor VIII concentrate using different assays and standardsJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 11 2003M. Morfini Summary., When the one-stage clotting assay is used in comparison with the chromogenic and immunological assays, plasma levels of factor (F)VIII are underestimated by 40,50% after infusion of B-domain deleted recombinant FVIII (BDD-rFVIII) in patients with hemophilia. A possible way to counteract the underestimation of FVIII levels by the one-stage assay is the adoption of a recombinant FVIII reference standard instead of a plasma standard. To evaluate the usefulness of such a standard [ReFacto® Laboratory Standard (RLS)], the pharmacokinetic parameters of a single dose of BDD-rFVIII (25 U kg,1) were evaluated in a multicenter study carried out in 18 patients with severe hemophilia A. The very low in vivo recovery, obtained with the combination of the one-stage assay and plasma reference standard, was increased up to the values obtained by the chromogenic assay when the results were expressed in terms of RLS. When the plasma standard was used, the one-stage/chromogenic ratio was 0.82 ± 0.12 for FVIII levels above 25 U dL,1 and 1.42 ± 0.99 for FVIII levels below 25 U dL,1. Using the RLS, the one-stage/chromogenic ratio increased to 1.01 ± 0.19 at FVIII levels above 25 U dL,1, as a consequence of a complete overlap of the two decays; however, at FVIII levels below 25 U dL,1, the one-stage/chromogenic ratio was still 1.6 ± 0.85. After the twelfth hour, FVIII concentrations obtained by chromogenic assay were always lower than those resulting from the one-stage clotting assay, independently of the standard used. Results obtained by chromogenic assay were not affected by the type of standard used. Compared with those obtained by the one-stage assay, higher values of clearance, lower volume of distribution area and shorter plasma half-life or mean residence time were obtained by chromogenic assay because of a shape change of the decay curve due to a shift to higher values in the first part (time interval 0,12 h) and to lower values in the second part of the decay curve (time interval 12,48 h). As a consequence, the slope of the decay curve obtained by means of chromogenic assay was steeper. In conclusion, the more homogeneous results of in vivo recovery and pharmacokinetic analysis, due to the decrease of discrepancy between the two methods when RLS was used, make the cheaper and more widely used one-stage assay preferable to the more expensive chromogenic assay, on condition that the ReFacto specific standard has used. [source] Quantification of Greenland halibut serum vitellogenin: a trip from the deep sea to the mass spectrometerRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 7 2009Alejandro M. Cohen This paper focuses on the sequential steps involved in developing a technique for quantifying Greenland halibut vitellogenin, a serum protein biomarker, using a comprehensive mass spectrometric approach. In the first phase of this study, in-gel trypsin digestions of serum proteins separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) were analyzed by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). A characteristic band around a molecular mass of 185,kDa, present in the mature female specimens, but absent in the male samples, was identified as vitellognin according to the peptide mass fingerprint obtained by MALDI-MS. Subsequently, MALDI and electrospray ionization tandem mass spectrometry (ESI-MS/MS) analyses were performed on the digest of the vitellogenin band for de novo sequencing. From these studies, a characteristic 'signature' peptide (sequence: FFGQEIAFANIDK) was selected from a list of candidate peptides as a surrogate analytical standard used for quantification purposes. Sample preparation for vitellogenin quantification consisted of a simple one-step overnight trypsin digestion. Samples were spiked with an isotopologue signature peptide standard and analyzed by high-performance liquid chromatography (HPLC) coupled in-line to an electrospray quadrupole-hexapole-quadrupole tandem mass spectrometer, operated in selective reaction monitoring mode. Transitions [(m/z 750.0,,,1020.4 and 750.0,,,1205.4) and (754.8,,,1028.6 and 754.8,,,1213.2)] were monitored for the signature peptide and the internal standard, respectively. Samples obtained from the field showed that vitellogenin levels were in accordance with fish maturity determined by macroscopic examination of the gonad, proving this technique suitable for measuring vitellogenin as a serum protein biomarker for reproductive maturity in female fish. Copyright © 2009 John Wiley & Sons, Ltd. [source] Condensed tannins in the diets of primates: a matter of methods?AMERICAN JOURNAL OF PRIMATOLOGY, Issue 1 2009Jessica M. Rothman Abstract To understand the ways in which condensed tannins (CT) affect primate diet selection and nutritional status, correct measurements are essential. In the majority of studies of the CT contents of primate foods, a tannin source such as "quebracho" is used to standardize CT assays, but the CT in quebracho tannin may not be similar to those in the plants of interest. We investigated how the choice of standard to calibrate CT assays affects the estimation of CT in the diets of mountain gorillas (Gorilla beringei). We purified the CT from gorilla foods and compared the actual amounts of CT in the foods with estimates produced by using the quebracho tannin. When quebracho was used, the estimates of CT contents of gorilla foods were, on average, 3.6 times the actual content of CT so that the amounts in frequently eaten gorilla foods were substantially overestimated. The overestimation for a given plant could not be predicted reliably and the ranking of plants by tannin content differed according to the standard used. Our results demonstrate that accurate measurements of CT necessitate the use of tannins purified from the plant species of interest. A reevaluation of primatology studies using interspecific comparisons of tannin content will provide new insights into primate food selection and nutritional ecology. Am. J. Primatol. 71:70,76, 2009. © 2008 Wiley-Liss, Inc. [source] Cystatin-C and beta trace protein as markers of renal function in pregnancyBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 5 2005Ayub Akbari Objective To assess the validity of Cystatin-C (Cys-C) and beta trace protein (BTP) as clinical markers of glomerular filtration rate (GFR) in pregnant women. Design Prospective cross sectional study. Setting Obstetric unit of a tertiary care hospital. Population One hundred and thirty-seven normal pregnant women and 13 women postpartum. Methods Twenty-four hour creatinine clearance (CrCl), serum creatinine, Cys-C and BTP concentrations were measured on normal pregnant women in the first trimester (n= 5), second trimester (n= 68) and third trimester (n= 64) and in 13 women postpartum. Data are given as median (2.5th centile, 97.5th centile). Main outcome measures Serum concentrations of Cys-C and BTP compared with creatinine clearance and serum creatinine. Results The median serum creatinine throughout gestation was 53 ,mol/L (39, 71), and median CrCl was 143 mL/minute (91 to 216). Postpartum, creatinine rose to 74 ,mol/L (58, 86) and CrCl decreased to 104 mL/minute (71, 159). For Cys-C, the median concentration was 0.70 mg/L (0.46, 1.32), and 0.54 mg/L (0.36, 0.96) for BTP. Comparing the second and third trimesters, there was no significant difference between CrCl (median 145 vs 141 mL/minute) and BTP concentrations (median 0.51 vs 0.55 mg/L), while median Cys-C was significantly higher in the third trimester (0.61 vs 0.88 mg/L; P < 0.001). Unlike creatinine and BTP, Cys-C levels decreased to 0.72 mg/L (0.57, 0.95) postpartum. The only significant relationship of either of these markers to the standard used for GFR was between Cys-C and CrCl in the third trimester, and the correlation was weak (r= 0.27 for 1/Cys-C vs CrCl). Conclusion These data demonstrate that despite claims to the contrary, Cys-C is a poor marker of GFR during pregnancy. Similarly, BTP shows little promise. [source] | ||||||||||