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Reproducible Results (reproducible + result)
Selected AbstractsRapid determination of enzyme activities of recombinant human cytochromes P450, human liver microsomes and hepatocytesBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 9 2003Anima Ghosal Abstract Cytochrome P450 (CYP) substrates that yield fluorescent metabolites were used for rapid screening of drug metabolism activities of 13 recombinant human cytochromes P450, human liver microsomes and human hepatocytes. Reproducible results were obtained using a fluorescent plate reader (CytoFluor) more expediently than those generated using conventional HPLC methods. Typically, results for 96 samples were obtained with the plate reader in less than 10 min as opposed to 15,35 min/sample required by conventional HPLC. The fluorescent substrates used to measure CYP activities were as follows: 3-cyano-7-ethoxycoumarin (CEC) for CYP1A1, CYP1A2, CYP2C9 and CYP2C19; 7-ethoxyresorufin (7-ER) for CYP1A1, CYP1A2 and CYP1B1; 3-[2-(N,N -diethyl- N -methylammonium)ethyl]-7-methoxy-4-methylcoumarin (AMMC) for CYP2D6; dibenzylfluorescein (DBF) for CYP3A4, CYP3A5 and CYP2C8; 7-methoxy-4-trifluoromethylcoumarin (7-MFC) for CYP2E1, CYP2B6 and CYP2C18; and coumarin for CYP2A6. The chemical inhibition and correlation data indicated that the following substrates can be used as specific functional probes for individual cytochrome P450 present in human liver microsomes: coumarin for CYP2A6 (r=0.82), AMMC for CYP2D6 (r=0.83) and DBF for CYP3A4 (r=0.92). The fluorescent plate reader was found to be useful for the rapid assessment of CYP activities (positive control) in both intact cells and subcellular fractions. Copyright © 2003 John Wiley & Sons, Ltd. [source] An evaluation of the Periotest® method as a tool for monitoring tooth mobility in dental traumatologyDENTAL TRAUMATOLOGY, Issue 2 2010Christine Berthold The aims of this study were to determine normal Periotest® values in the vertical and horizontal dimensions of periodontally healthy teeth in individuals aged 20,35 years and investigate the reliability of Periotest® in terms of intra-series and inter-series reproducibility before and after applying a dental trauma splint in vivo. Materials and methods:, Periotest® values were measured in periodontally healthy dental students (n = 33; mean age 24.7 years) at reproducible measuring points in the vertical and horizontal dimensions, before and after splint insertion. Three readings were taken per series to observe the intra-series reproducibility; three series were measured to test inter-series reproducibility (Friedman-test; P , 0.001). Two different wire-composite splints, 0.45 mm Dentaflex and 0.8 × 1.8 Strengtheners, were inserted and the Periotest® values were measured. Results:, The median Periotest® values before splinting were: canines -2.5, lateral incisors -0.9, and central incisors 0.0 for the vertical dimension, and canines 1.1, lateral incisors 3.2, and central incisors 3.6 for the horizontal dimension. The intra-series and inter-series Periotest® values were highly reproducible. Conclusion:, The Periotest® method provides highly reproducible results. Focused on dental trauma, the method can be applied diagnostically during the splint and follow-up period and for evaluating splint rigidity. [source] Determination of melatonin in wine and plant extracts by capillary electrochromatography with immobilized carboxylic multi-walled carbon nanotubes as stationary phaseELECTROPHORESIS, Issue 13 2010Patricia W. Stege Abstract The finding of melatonin, the often called "hormone of darkness" in plants opens an interesting perspective associated to the plethora of health benefits related to the moderate consumption of red wine. In this study, the implementation of a new method for the determination of melatonin in complex food matrices by CEC with immobilized carboxylic multi-walled carbon nanotubes as stationary phase is demonstrated. The results indicated high electrochromatographic resolution, good capillary efficiencies and improved sensitivity respect to those obtained with conventional capillaries. In addition, it was demonstrated highly reproducible results between runs, days and columns. The LOD for melatonin was 0.01,ng/mL. The method was successfully applied to the determination of melatonin in red and white wine, grape skin and plant extracts of Salvia officinalis L. [source] Carboxylic multi-walled carbon nanotubes as immobilized stationary phase in capillary electrochromatography,ELECTROPHORESIS, Issue 18 2008Lorena Sombra Abstract Carboxylic multi-walled carbon nanotubes (c-MWNT) have been immobilized into a fused-silica capillary for capillary electrochromatography. The c-MWNT were successfully incorporated after the silanization and coupling with glutaraldehyde on the inner surface of the capillary. The electrochromatographic features of the c-MWNT immobilized stationary phase have been evaluated for the analysis of different compounds of pharmaceutical interest. The results indicated high electrochromatographic resolution, good capillary efficiency and retention factors. In addition, highly reproducible results between runs, days and capillaries were obtained. [source] Optimization of capillary electrophoretic enantioseparation for basic drugs with native ,-CD as a chiral selectorELECTROPHORESIS, Issue 12 2006Nerissa L. Deńola Abstract This study presents the advantages of the 20,µm inner diameter (id) capillary for the enantioseparation of ten basic drugs with native ,-CD as the chiral selector. The apparent binding constants of each enantiomeric pair were determined to calculate the optimum ,-CD concentration ([,-CD]opt) and the optimization was subsequently carried out. Comparison of the 20,µm id with 50,µm id were made in terms of the results obtained in the optimization and detection limits. Applying the optimum conditions for each compound, reproducible results (RSD from 0,3; n>5) were obtained for the 20,µm id capillary. Although the sensitivity is lower in the 20,µm id capillary, the LOD determined using this capillary is still found to be acceptable for the ten basic drugs studied. Enhanced resolution and faster analysis times were the main advantages observed with the use of this capillary in enantioseparation. [source] A Facile Method for the Preparation of Gold Glyconanoparticles from Free Oligosaccharides and Their Applicability in Carbohydrate-Protein Interaction Studies,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 17 2005Koen M. Halkes Abstract The weak binding affinity of monomeric oligosaccharides with carbohydrate-binding proteins are hampering their use in in-vivo and in-vitro bio-assays. Gold glyconanoparticles (GNPs), prepared from synthetic oligosaccharides, have been used to overcome this weak binding affinity. In this paper, a convenient method for the preparation of GNPs from free oligosaccharides is presented. The reductive amination of saccharides with trityl-protected cysteamine, followed by de-tritylation, afforded cysteamine-extended saccharides that could be used for the preparation of GNPs under reducing conditions in water. The robust chemistry and facile purification of intermediate and final compounds ensure high yields and reproducible results and the, subsequent, preparation of GNPs proceeded smoothly, even with minute quantities (nanomolar scale) of the cysteamine-extended saccharide. The described method was used to synthesize a series of gluco - and manno -oligosaccharide-containing GNPs. The prepared GNPs were validated in interaction studies with Con A, using either surface plasmon resonance (SPR), UV/Vis spectroscopy, or transmission electron microscopy (TEM). The described method for the preparation of water-soluble gold glyconanoparticles can be used for the identification of carbohydrate ligands for novel carbohydrate-binding proteins, and can find application as inhibitors of pathological interactions. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Measuring remanence anisotropy of hematite in red beds: anisotropy of high-field isothermal remanence magnetization (hf-AIR)GEOPHYSICAL JOURNAL INTERNATIONAL, Issue 3 2009Dario Bilardello SUMMARY The potential of using high-field anisotropy of isothermal remanence magnetization (hf-AIR) measurements for determining the origin of natural remanent magnetization in red beds and for identifying and correcting possible red-bed inclination shallowing was investigated for specimens of the Carboniferous Shepody Formation of New Brunswick and Nova Scotia, Canada. The technique makes it possible for a typical paleomagnetic laboratory to measure the remanence anisotropy of high-coercivity hematite. High-field (hf) AIR was used in conjunction with 100 mT alternating field (af) and 120 °C thermal demagnetization to separate the contribution of hematite to the remanence anisotropy from that of magnetite/maghemite and goethite, respectively. A 5-T impulse DC magnetic field was used for the hf-AIR to reset the magnetic moment of high-coercivity hematite so that demagnetization between AIR orientations was not necessary. The ability of a 5-T field to reset the magnetization was tested by generating an isothermal remanent magnetization acquisition curve for hematite by using impulse DC magnetic fields up to 5 T in one orientation and followed by applying a field in the opposite direction at each step. Each field application was treated by 120 °C heating and 100 mT af demagnetization before measurement. At 5 T, the difference between the magnetizations applied in opposite directions disappeared indicating that no magnetic memory persisted at this field strength. We performed a validity and reproducibility test of our hf-AIR measurement technique by measuring three specimens multiple times along two orthogonal coordinate systems. The method yielded highly reproducible results and, on rotating the specimen's coordinates, the fabric rotated by 90° as expected, showing that it is not an artifact of the technique. We also measured hf-AIR on samples that had previously been chemically demagnetized in 3N HCl to remove the secondary, chemically grown pigmentary hematite. The hf-AIR fabric of leached samples is similar to that of untreated samples, but shows a better-defined magnetic lineation and imbrication. We interpret the fabric observed for the Shepody Formation to be a compactional fabric that has been reoriented by strain during folding following a flexural-slip model. [source] Quantitative analysis of human mitochondrial DNA using a real-time PCR assayHIV MEDICINE, Issue 3 2003K Gourlain Objectives Known for their ability to inhibit the human DNA polymerase-,, nucleoside analogues induce toxic effects on mitochondria ranging from increased serum lactate levels to fatal lactic acidosis. DNA polymerase-, ensures the mitochondrial DNA (mtDNA) replication and, thus, its inhibition leads to the decrease of the mtDNA. We describe a real-time PCR assay for mtDNA quantification associating DNA extraction procedures applied on peripheral blood mononuclear cells (PBMCs) and subcutaneous adipose tissues and to study the antiretroviral effect on mitochondria. Methods Total DNA was extracted from PBMCs and subcutaneous adipose tissues. Nuclear and mitochondrial genes were amplified to determine the number of copies of mtDNA per cell using a cyt-b recombinant plasmid as standard control. We analysed eight HIV-infected asymptomatic patients never treated, four patients who had been treated for 6 months with highly active antiretroviral therapy (HAART) and six non-infected donors. Results The mtDNA quantification gave rise to reproducible results as the mean coefficients of variation were 1.09% for replicates of samples undertaken 10 times within the same run, and 5.78% and 3.7% for replicates tested in five different runs at 1:100 and 1:1000 dilutions, respectively. Median levels of mtDNA in PBMCs of healthy donors, naive and treated HIV-infected patients were 2.94, 2.78 and 1.93 log HIV-1 RNA copies/mL, respectively. Whereas DNA from PBMCs was shown to be devoid of inhibitors, subcutaneous adipose tissues needed an extra treatment as they were found to be highly inhibited. Conclusions The method generated consistent and reproducible results and was successfully applied to DNAs extracted from PBMCs and subcutaneous adipose tissues with adapted extraction. The mtDNA changes in PBMCs were found to be fast as they fall off after 6 months' therapy, decreasing from 2.78 to 1.93 log copies/mL. [source] Pyrosequencing for detection of mutations in the connexin 26 (GJB2) and mitochondrial 12S RNA (MTRNR1) genes associated with hereditary hearing loss,HUMAN MUTATION, Issue 4 2002Alessandro Ferraris Abstract Hereditary hearing loss (HHL) is one of the most common congenital disorders and is highly heterogeneous. Mutations in the connexin 26 (CX26) gene (GJB2) account for about 20% of all cases of childhood deafness, and approach 50% in documented recessive cases of non-syndromic hearing loss. In addition, a single mitochondrial DNA mutation, mt1555A>G, in the 12S rRNA gene (MTRNR1), is associated with familial cases of progressive deafness. Effective screening of populations for HHL necessitates rapid assessment of several of these potential mutation sites. Pyrosequencing links a DNA synthesis protocol for determining sequence to an enzyme cascade that generates light whenever pyrophosphate is released during primer strand elongation. We assessed the ability of Pyrosequencing to detect common mutations causing HHL. Detection of the most common CX26 mutations in individuals of Caucasian (35delG), Ashkenazi (167delT), and Asian (235delC, V37I) descent was confirmed by Pyrosequencing. A total of 41 different mutations in the CX26 gene and the mitochondrial mt1555A>G mutation were confirmed. Genotyping of up to six different adjacent mutations was achieved, including simultaneous detection of 35delG and 167delT. Accurate and reproducible results were achieved taking advantage of assay flexibility and experimental conditions easily optimized for a high degree of standardization and cost-effectiveness. The standardized sample preparation steps, including target amplification by PCR and preparation of single-stranded template combined with automated sequence reaction and automated genotype scoring, positions this approach as a potentially high throughput platform for SNP/mutation genotyping in a clinical laboratory setting. Hum Mutat 20:312,320, 2002. © 2002 Wiley-Liss, Inc. [source] Neccesity for Standardization in Fluorescence Pattern AnalysisIMAGING & MICROSCOPY (ELECTRONIC), Issue 1 2009Petra Perner Dr. Fluorescent pattern analysis is used in cellular and molecular biology as well as in medicine, agriculture or other applications. To make it feasible in daily practice, standardization is necessary to obtain authentically and reproducible results. Standardization has many aspects (fig. 1). It has to do with sample preparation, imaging techniques, knowledge acquisition, and image interpretation. It is an iterative process and cannot be solved from scratch. [source] Nanowire-Based High-Performance "Micro Fuel Cells": One Nanowire, One Fuel Cell,ADVANCED MATERIALS, Issue 9 2008Caofeng Pan A micrometer-sized fuel cell based on Nafion/poly(vinyl pyrrolidone) nanowires is presented. The high-performance micro fuel cell containing a single NPNW proved easy to fabricate and delivered reproducible results. Values for the open-circuit voltage, maximum current-density, and power density were orders of magnitude higher than those of traditional fuel cells (see figure). Micro fuel cell assemblies may have future applications in integrated self-powered nanodevices. [source] Absorption kinetics of oxygen scavengersINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 2 2002Gaurav Tewari The oxygen (O2) absorption kinetics of six commercial O2 scavengers were studied. The scavengers were placed in bags which were filled with 240 mL of air, 4.5 L N2 + 15 mL of air, or 3.5 L CO2 + 9 mL of air. The O2 concentration in each bag was measured at hourly intervals for 8 h. The effects of variability among individual scavengers, initial O2 concentrations of 20% or 500 ppm (0.05%), temperatures of 25, 12, 2 or ,1.5 °C, and scavenger capacity on the O2 absorption rate were determined. In addition, the effect of placing scavengers within over-wrapped trays within bags, was examined. Rates of O2 absorption varied by factors of up to 2 between individual O2 scavengers of the same type, but rates of absorption by groups of four scavengers of the same type were similar. Low temperatures gave longer O2 half-life when compared with those at higher temperatures, e.g. O2 half-lives of 7.1 and 1.0 h at ,1.5 and 25 °C, respectively, were obtained for one scavenger type. Shorter O2 half-lives were obtained in air than in N2 atmospheres at the same temperature, e.g. O2 half-lives of 1.0 and 3.3 h in air and N2 at 25 °C, respectively, were obtained for one scavenger type. The O2 absorption reactions were of first order for both high and low initial O2 concentrations. However, O2 concentration was the primary limiting factor for O2 absorption in atmospheres having O2 concentration of 500 ppm because of the dominance of diffusion. Scavengers, when placed within over-wrapped trays within bags had up to 12 times longer O2 half-lives, indicating that the O2 permeable film acts as an O2 barrier when pack atmosphere has low O2 concentrations. To obtain consistent and reproducible results, it is recommended that multiple scavengers be used in a packaging system. The appropriate number should be based on scavenger type, desired O2 absorption rate, storage temperature, and pack atmosphere (air/N2/CO2). [source] Minisequencing-Based Genotyping of Duffy and ABO Blood Groups for Forensic PurposesJOURNAL OF FORENSIC SCIENCES, Issue 2 2006Gianmarco Ferri Ph.D. ABSTRACT: Duffy and ABO blood group genetic polymorphisms were studied by minisequencing analysis of single-nucleotide polymorphisms (SNPs) at nucleotide positions,33, 125, 265, and 298 of the Duffy gene and at nucleotide positions,261, 297, 467, 646, and 703 of the ABO gene. In an Italian population sample, we found four alleles and seven genotypes for the Duffy and six alleles and 16 genotypes for the ABO systems. The lower limit for reproducible results was 200 pg DNA, with a range of up to 10 ng and an optimum at 1 ng. All of the 16 analyzed inclusive paternity tests were also consistent with parentage and two out of four inconsistencies with parentage cases were excluded by one or more SNPs. Although Duffy and ABO SNP typing show lower informativeness than most current forensic tests, their robustness, the limited population distribution of FY*Fy type, and the sensitivity of the minisequencing technology suggest that these markers can be useful in selected forensic applications. [source] Measurement of bone blood flow using the hydrogen washout technique,part II: Validation by comparison to microsphere entrapmentJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 6 2008Mikko Larsen Abstract Accurate and reproducible measurement of bone blood flow has important clinical and experimental applications. Hydrogen washout is simple, safe, and widely used, but its use in bone tissue has not been validated. To this end, we have compared cortical bone blood flow measurements obtained by radioactive-labeled microsphere entrapment with those from hydrogen washout. Blood flow was measured in tibial cortical bone of 12 New Zealand White rabbits by radioactive microsphere entrapment and by hydrogen washout. Besides a control group (n,=,6), four animals were treated with systemic epinephrine (0.8 µg/kg/min) (group 2) and two with nitroprusside (100 µg/kg/min) (group 3). Furthermore, nine femora from seven rats were isolated on their vascular pedicles and repeated bone blood flow measurements were made at each location with the hydrogen washout method to confirm reproducibility of blood flow determinations by hydrogen washout. An average flow of 2.3,±,2.0 mL/min/100 g was obtained with the microsphere method and 2.0,±,0.5 mL/min/100 g with the hydrogen washout method. There was a significant correlation and agreement: R2,=,0.97 (p,<,0.01). No consistent flow variations were found with systemic vasoactive drug administration. Hydrogen washout provided reproducible results and showed high sensitivity to flow changes. Hydrogen washout is both sensitive and reproducible in measuring bone blood flow. Results agree well with flow values obtained by labeled microsphere entrapment. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:746,752, 2008 [source] Fast analysis in liquid chromatography using small particle size and high pressureJOURNAL OF SEPARATION SCIENCE, JSS, Issue 12 2006Dao T.-T. Abstract In order to enhance chromatographic performances in terms of efficiency and rapidity, LC has recently evolved in the development of short columns packed with small particles (sub-2 ,m) working at high pressures (>400 bar). This approach has been described 30 years ago according to the fundamental chromatographic equations. However, systems and columns compatible with such high pressures have been introduced in the market in 2004 only. Advantages of small particles working at high pressure will be discussed in terms of sensitivity, efficiency, resolution, and analysis time. Potential problems encountered with high pressure in terms of frictional heating and solvent compressibility will also be discussed even if systems working at a maximum pressure of 1000 bar are not influenced by these parameters and give reliable and reproducible results. Several applications will highlight the potential and interest of this new technology. [source] An evaluation of the robustness of the Tanaka characterization protocol for reversed-phase liquid chromatography columnsJOURNAL OF SEPARATION SCIENCE, JSS, Issue 16 2005Patrik Petersson Abstract The robustness of the popular ,Tanaka' LC column characterization protocol has been evaluated by the statistical tools of reduced factorial design, multiple linear regression and principal component analysis. These have shown that in order to obtain reliable and reproducible results, it is especially important to control the methanol content, the temperature and, in the case of the total ion-exchange capacity test (,B/P pH 7.6), the pH of the mobile phase. In particular, the hydrophobicity tests (kPB and ,) are sensitive to small changes in methanol content. Provided that the operating parameters for the Tanaka column characterization protocol are controlled within the following experimental limits, i. e. methanol content ±0.5% v/v, temperature ±3°C, pH ±0.10 and buffer concentration ±2.0 mM, it is feasible to distinguish between RP materials that possess selectivity differences larger than their batch-to-batch reproducibility. These experimental requirements can be easily met by current LC instrumentation. Hence, the validity of the Tanaka testing protocol for characterizing columns has been verified. [source] Evaluation of a Novel Real-Time Continuous Glucose-Monitoring System for Use in CatsJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2010S. Moretti Background: The Guardian REAL-Time is a continuous glucose-monitoring system (CGMS) recently developed to provide instantaneous interstitial glucose concentrations; the system does not require a monitor being fixed to the animal. Hypothesis: The CGMS provides accurate and reproducible real-time readings of glucose concentration in cats. Animals: Thirty-two diabetic cats, 2 cats with suspected insulinoma, and 5 healthy cats. Methods: Prospective, observational study. CGMS accuracy was compared with a reference glucose meter at normal, high, and low blood glucose concentrations using error grid analysis. Reading variability of 2 simultaneously used CGMS was determined in diabetic cats by calculating correlation and percentage of concordance of paired data at different glycemic ranges. The time interval between increasing glycemia and a rise in interstitial fluid glucose measured by the CGMS was assessed in healthy cats receiving glucose IV; the time point of maximal increase in interstitial glucose concentrations was calculated. Results: The CGMS was 100, 96.1, and 91.0% accurate at normal, high, and low blood glucose concentrations. Measurements deviated from reference by ,12.7 ± 70.5 mg/dL at normal, ,12.1 ± 141.5 mg/dL at high, and ,1.9 ± 40.9 mg/dL at low glucose concentrations. Overall, paired CGMS readings correlated significantly (r= 0.95, P < .0001) and concordance was 95.7%. The median delay after IV administration of glucose to an increase in interstitial glucose was 11.4 minutes (range: 8.8,19.7 minutes). Conclusions and Clinical Importance: Although some readings substantially deviated from reference values, the CGMS yields reproducible results, is clinically accurate in cats with hyperglycemia and euglycemia, and is slightly less accurate if blood glucose concentrations are low. Rapidly increasing interstitial glucose after a glycemic rise suggests that the CGMS is suitable for real-time measurement under clinical conditions. [source] Laser scanner analysis in reconstruction of traumatic laceration of the facial nerveLASER PHYSICS LETTERS, Issue 6 2007D.F. Kalbermatten Abstract To present a new concept of outcome analysis after immediate reconstruction of traumatic lesions of the frontal branch of the facial nerve. With the aid of laser surface scanning, changes induced by frontal muscle contraction, i.e. frowning, in skin surface area on the forehead were measured in nine patients after repair of traumatic transection of the frontal branch of the facial nerve and in 10 healthy volunteers. With laser surface scanning analysis, consistent changes in surface area on the forehead were measured in both patients and healthy volunteers. Symmetry of 74 ± 15% in forehead wrinkling was obtained 12 months after coaptation of the transected nerve. Laser surface scanning is a promising tool to assess outcome after repair of facial nerve laceration. It is easy to use, yields reproducible results and might be used in the future for other procedures. (© 2007 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] Technical advance in fungal biotechnology: development of a miniaturized culture method and an automated high-throughput screeningLETTERS IN APPLIED MICROBIOLOGY, Issue 2 2009F. Alberto Abstract Aims:, The goal of the study was to develop a reliable, reproducible and rapid method of culture in order to screen a large number of fungal transformants. Methods and Results:, The method is based upon miniaturized cell cultures and automated expression screening in microwell plates. For the method development, 50 recombinant Aspergillus vadensis clones producing feruloyl esterase B (FaeB) from Aspergillus niger were screened in 6 days. Then a panel of clones showing various behaviours was checked in flasks in order to demonstrate the reproducibility of the method. Using this method, a transformant of A. vadensis producing 1·2 g l,1 of FaeB was selected (12-fold more than the A. niger overproducing strain). Conclusions:, This miniaturized culture method allows to obtain reliable and reproducible results. The procedure has the advantages of being efficient, time-saving and more efficient than conventional in-flask culture screening as it can screen 800 clones per day after a culture of 3 days. Significance and Impact of the Study:, This method could be applied to any other fungal strain culture, enzyme activity or biodiversity screening. [source] Effects of delayed excision of oviducts/ovaries on mouse oocytes and embryosMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 4 2007De-Qiang Miao Abstract To achieve the best and reproducible results of experiments, effects of delayed excision of oviducts/ovaries on mouse ovarian/ovulated oocytes and embryos have been studied. Oviducts/ovaries were excised at different times after death of mice and effects of the postmortem interval on ovarian/ovulated oocytes and embryos were analyzed. When oviduct excision was delayed 10 min, many ovulated oocytes lysed or underwent in vitro spontaneous activation, and this postmortem effect aggravated with the extension of postmortem interval and oocyte aging. Oocytes from different mouse strains responded differently to delayed oviduct removal. Delayed oviduct excision did not cause lysis of zygotes or embryos but compromised their developmental potential. When ovaries were excised at 30 min after death, percentages of atretic follicles increased while blastocyst cell number declined significantly after oocyte maturation in vitro. Preservation of oviducts in vitro, in intact or opened abdomen at different temperatures and histological analysis of oviducts from different treatments suggested that toxic substance(s) were secreted from the dying oviducts which induced oocyte lysis and spontaneous activation and both this effect itself and the sensitivity of oocytes to this effect was temperature dependent. It is concluded that a short delay of oviduct/ovary removal had marked detrimental effects on oocytes and embryos. This must be taken into account in experiments using oocytes or embryos from slaughtered animals. The data may also be important for estimation of the time of death in forensic medicine and for rescue of oocytes from deceased valuable or endangered mammals. Mol. Reprod. Dev. 74: 468,477, 2007. © 2006 Wiley-Liss, Inc. [source] Testing high SPF sunscreens: a demonstration of the accuracy and reproducibility of the results of testing high SPF formulations by two methods and at different testing sitesPHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 4 2002Patricia Poh Agin Background/Purpose: The goals of this study were (i) to demonstrate that existing and widely used sun protection factor (SPF) test methodologies can produce accurate and reproducible results for high SPF formulations and (ii) to provide data on the number of test-subjects needed, the variability of the data, and the appropriate exposure increments needed for testing high SPF formulations. Methods: Three high SPF formulations were tested, according to the Food and Drug Administration's (FDA) 1993 tentative final monograph (TFM) ,very water resistant' test method and/or the 1978 proposed monograph ,waterproof' test method, within one laboratory. A fourth high SPF formulation was tested at four independent SPF testing laboratories, using the 1978 waterproof SPF test method. All laboratories utilized xenon arc solar simulators. Results: The data illustrate that the testing conducted within one laboratory, following either the 1978 proposed or the 1993 TFM SPF test method, was able to reproducibly determine the SPFs of the formulations tested, using either the statistical analysis method in the proposed monograph or the statistical method described in the TFM. When one formulation was tested at four different laboratories, the anticipated variation in the data owing to the equipment and other operational differences was minimized through the use of the statistical method described in the 1993 monograph. Conclusions: The data illustrate that either the 1978 proposed monograph SPF test method or the 1993 TFM SPF test method can provide accurate and reproducible results for high SPF formulations. Further, these results can be achieved with panels of 20,25 subjects with an acceptable level of variability. Utilization of the statistical controls from the 1993 sunscreen monograph can help to minimize lab-to-lab variability for well-formulated products. [source] On the design of end tabs for quasi-static and fatigue testing of fibre-reinforced compositesPOLYMER COMPOSITES, Issue 4 2009I. De Baere The use of end tabs is often necessary when performing quasi-static uniaxial tests on fibre-reinforced composites. However, finding a suitable combination of material and geometry for these end tabs to have acceptable and reproducible results may be a problem. In this article four different geometries and four different materials of the tabs are numerically examined for the tensile testing of a carbon fabric reinforced polyphenylene sulphide. First, it is assessed if a simplified finite element model of a tensile grip is acceptable. Then, this simplified model is used to examine the proposed set-ups. It may be concluded that, for the given material, short straight end tabs with a [(0°,90°)]4s layup should be used and the specimen should be mounted in such a way that the end tabs are completely between the grips. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers [source] Fifty years of antineutrophil cytoplasmic antibodies (ANCA) testing: do we need to revise the international consensus statement on testing and reporting on ANCA?APMIS, Issue 2009JAN WILLEM COHEN TERVAERT During the first international workshop on antineutrophil cytoplasmic antibodies (ANCA), Copenhagen 25 and 26 January 1988, ANCA, as detected by the indirect immunofluorescence (IIF) technique, was extensively discussed. Cytoplasmic fluorescence pattern was found in patients with vasculitis. In contrast, perinuclear fluorescence pattern was found in vasculitis but also in many other inflammatory disorders. At the workshop, it was stated that IIF should be combined with an antigen-specific technique and capture and direct enzyme-linked immunosorbent assay techniques were discussed. In 1999/2003, an international consensus statement on testing and reporting on ANCA was published. For vasculitis, IIF was advocated as a screening assay, followed by an antigen-specific assay. In other non-vasculitic inflammatory diseases, only IIF on ethanol-fixed granulocytes was advocated. Recently, it was demonstrated that antigen-specific tests could be used as screening tests. Furthermore, it became clear that antigen-specific tests, in which antigens are directly coated to the solid phase, demonstrate highly variable sensitivities and specificities, whereas when capture or anchor technologies are used, more reproducible results are obtained. Based on these studies, we propose that the international consensus statement on ANCA should be revised. [source] Using fractional exhaled nitric oxide to guide asthma therapy: design and methodological issues for ASthma TReatment ALgorithm studiesCLINICAL & EXPERIMENTAL ALLERGY, Issue 4 2009P. G. Gibson Prof. Summary Background Current asthma guidelines recommend treatment based on the assessment of asthma control using symptoms and lung function. Noninvasive markers are an attractive way to modify therapy since they offer improvedselection of active treatment(s) based on individual response, and improvedtitration of treatment using markers that are better related to treatment outcomes. Aims: To review the methodological and design features of noninvasive marker studies in asthma. Methods Systematic assessment of published randomized trials of asthma therapy guided by fraction of exhaled nitric oxide(FENO). Results FENO has appeal as a marker to adjust asthma therapy since it is readily measured, gives reproducible results, and is responsive to changes in inhaled corticosteroid doses. However, the five randomised trials of FENO guided therapy have had mixed results. This may be because there are specific design and methodological issues that need to be addressed in the conduct of ASthma TReatment ALgorithm(ASTRAL) studies. There needs to be a clear dose response relationship for the active drugs used and the outcomes measured. The algorithm decision points should be based on outcomes in the population of interest rather than the range of values in healthy people, and the algorithm used needs to provide a sufficiently different result to clinical decision making in order for there to be any discernible benefit. A new metric is required to assess the algorithm performance, and the discordance:concordance(DC) ratio can assist with this. Conclusion Incorporating these design features into future FENO studies should improve the study performance and aid in obtaining a better estimate of the value of FENO guided asthma therapy. [source] | ||||||||||||||||||||||