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Clinical Laboratories (clinical + laboratory)

Distribution by Scientific Domains

Medical Sciences	70%
Life Sciences	13%
Chemistry	10%
2 Other Domains	7%

Terms modified by Clinical Laboratories

clinical laboratory standards

Selected Abstracts

Assessment of protein-incorporated arginine methylation in biological specimens by CZE UV-detection

ELECTROPHORESIS, Issue 23 2007
Angelo Zinellu Dr.
Abstract Protein arginine methyltransferases methylate post-translationally arginine residues in proteins to synthesize monomethylarginine (MMA), asymmetric dimethylarginine (ADMA), or symmetric dimethylarginine. Protein arginine methylation is involved in the regulation of signal transduction, RNA export, and cell proliferation. Moreover, upon proteolysis, arginines are released into the cytosol in which they exert important biological effects. Both MMA and ADMA are inhibitors of nitric oxide synthase and especially elevated levels of ADMA are associated with endothelial dysfunction and cardiovascular disease. Quantification of these analytes is commonly performed by HPLC after sample cleanup and derivatization. We propose a CE method in which these steps have been avoided and the procedure for sample preparation has been simplified. After acidic hydrolysis of proteins, samples were dried, resuspended in water, and directly injected in CE. A baseline separation of analytes was reached in a 60 cm×75,,m id uncoated silica capillary, by using a Tris-phosphate run buffer at pH,2.15. This method allows an accurate assessment of protein arginine methylation degree in different biological samples such as whole blood, plasma, red blood cells, cultured cells, and tissue. Moreover, its good sensitivity permits to evaluate the methylation of a single protein type after the opportune purification steps. A method applicability concerns both clinical laboratories, where the evaluation of blood protein from numerous samples could be rapidly performed, and research laboratories where the factors affecting the arginine protein methylation degree could be easily studied. [source]

High Level of Antimicrobial Resistance in French Helicobacter pylori Isolates

HELICOBACTER, Issue 1 2010
Josette Raymond
Abstract Background: Helicobacter pylori is a human pathogen responsible for serious diseases including peptic ulcer disease and gastric cancer. The recommended triple therapy included clarithromycin but increasing resistance has undermined its effectiveness. It is therefore important to be aware of the local prevalence of antimicrobial resistance to adjust treatment strategy. Materials and Methods: Overall, 530 biopsies were collected between 2004 and 2007. The antimicrobial susceptibility of H. pylori was determined by E-test and molecular methods. Results: Among these, 138/530 (26%) strains were resistant to clarithromycin, 324/530 (61%) to metronidazole and 70/530 (13.2%) to ciprofloxacin. Whereas no resistance against amoxicillin and tetracycline was observed, only one strain was resistant to rifampicin. Compared to the patients never treated for H. pylori infection, the prevalence of resistance was significantly higher in patients previously treated (19.1% vs 68% for clarithromycin; 13.2% vs 53.3% for both clarithromycin and metronidazole). The trend analysis revealed an increase of primary resistance to ciprofloxacin between 2004 and 2005 (7.3%) vs 2006,2007 (14.1%) (p = .04) and the secondary resistance reached 22.7% in 2007. Interestingly, 27 biopsies (19.6%) contained a double population of clarithromycin-susceptible and -resistant strains. Conclusions: The reported high prevalence of clarithromycin and multiple resistances of H. pylori suggest that the empiric therapy with clarithromycin should be abandoned as no longer pretreatment susceptibility testing has assessed the susceptibility of the strain. As culture and antibiogram are not routinely performable in most clinical laboratories, the use of molecular test should be developed to allow a wide availability of pretreatment susceptibility testing. [source]

Detection of single nucleotide substitution by competitive allele-specific short oligonucleotide hybridization (CASSOH) with immunochromatographic strip,

HUMAN MUTATION, Issue 2 2003
Yoichi Matsubara
Abstract Recent advances in human genome research have revealed that genetic polymorphisms, such as single nucleotide polymorphisms (SNPs), are closely associated with susceptibility to various common diseases and adverse drug reactions. Also, numerous mutations responsible for a number of genetic diseases have been identified. Clinical application of genetic information to individual health care requires simple and rapid identification of nucleotide changes in clinical settings. We have devised a novel low-tech method for the detection of a single nucleotide substitution using competitive allele-specific short oligonucleotide hybridization with immunochromatographic strip. The gene of interest is PCR-amplified, hybridized to an allele-specific short oligonucleotide probe in the presence of a competitive oligonucleotide, and subjected to chromatography using a DNA test strip at room temperature. The genotype is unambiguously determined by the presence or the absence of visible purple lines on a strip. Feasibility of the method was demonstrated by the detection of a prevalent disease-causing mutations in glycogen storage disease type Ia (G6PC), medium-chain acyl-CoA dehydrogenase deficiency (ACADM), non-ketotic hyperglycinemia (GLDC), and clinically important polymorphisms in the CYP2C19 gene and the aldehyde dehydrogenase 2 gene (ALDH2). The procedure does not demand either technical expertise or expensive instruments and is readily performed in local clinical laboratories. The result is obtained within 10 min after PCR. This rapid and simple method of SNP detection may be used for point-of-care genetic diagnosis with potentially diverse clinical applications. Hum Mutat 22:166,172, 2003. © 2003 Wiley-Liss, Inc. [source]

Evaluation of Ves-Matic Cube 200 , an automated system for the measurement of the erythrocyte sedimentation rate

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 1p2 2010
E. PEROVIC
Summary Ves-Matic Cube 200 is fully automated analyzer that performs erythrocyte sedimentation rate (ESR) measurement using the standard ethylenediaminetetraacetic acid blood sample tube, thus markedly reducing the analytical time and avoiding the need for an extra blood sample. The aim of this study was to assess the automatic Ves-Matic Cube 200 system for the measurement of ESR in comparison with the original International Council for Standardization in Hematology reference method (Westergren). The evaluation comprised accuracy which was established using a 95% confidence interval (CI) for the mean difference between Ves-Matic Cube 200 and Westergren method (mean of difference: 0.47 ± 6.84 mm/h; 95% CI: ,0.376 to 1.325 mm/h), within-run imprecision for samples with ESR values of 9, 42 and 95 mm/h (coefficients of variation: 9.19%, 13.88% and 5.66%, respectively) and method comparison (, = 0.95; Passing-Bablok regression equation: Y = ,0.0435 + 1.0435 X; bias: ,0.5; limits of agreement: ,13.9 to 12.9). Stability was estimated after 24 h storage either at 4 °C and room temperature (mean of differences: ,1.91 mm/h; 95% CI: ,4.852 to 1.037 mm/h and mean of differences: ,12.48 mm/h; 95% CI: ,16.580 to ,8.390 mm/h, respectively). The obtained results suggest that the Ves-Matic Cube 200 automated analyzer is reliable system for the measurement of ESR in clinical laboratories. [source]

EQAS for peripheral blood morphology in Spain: a 6-year experience

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 6 2008
G. GUTIÉRREZ
Summary The Spanish haematology external quality assessment scheme (EQAS), established in 1984, is run by the Spanish Haematology and Haemotherapy Association (AEHH) [Quality Assurance in Health Care 3 (1991) 75] and functions to evaluate the quality and reproducibility of the assessment of diagnostic samples by clinical laboratories. The Hospital Clinic of the University of Barcelona (HCB) serves as the EQAS Coordination Centre and follows the guidelines established by the International Committee for Standardization in Haematology [Annali dell'Istituto superiore di Sanità 31 (1995) 95; International Journal of Hematology 68 (1998) 45]. During the period 2001,2006, replicates of 25 different blood films were sent to 604 EQAS participants for cell morphology evaluation. Some patient details corresponding to the samples were disclosed, such us age, sex, haemoglobin value and white blood cell count. The participants were asked to select up to four significant morphology features using a coding list, provided by the Coordination Centre, which included significant morphological alterations that appear in haematopoietic cells. For each survey, individual results were assessed against the morphological reference results (MRR) established by the Cytology Group of the AEHH (,true' answers). This paper describes the organization of the 6-year-long study and the evaluation of laboratory performance for blood smear interpretation by the Spanish haematology EQAS. Different performance levels were detected relative to the laboratory category. Laboratories providing services to hospitalized patients showed higher performances compared with laboratories providing services to nonhospitalized patients. Pathological lymphoid cells were the most difficult to identify by the participants. To improve the results in EQAS peripheral blood morphology, the development of specific cytology educational trainings is discussed. [source]

Separation of haemoglobin HbE and HbA2 by the fully automated, high-pressure liquid chromatography Tosoh HLC-723 G7 analyzer

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 5 2008
G. LIPPI
Summary High-pressure liquid chromatography instruments specifically devised for separating haemoglobin (Hb) fractions have been increasingly employed by the hospital laboratories over the recent years since they allow easy and fast screening for several Hb variants. Although such instruments may be proposed as sensitive, specific and reliable alternatives to the classic electrophoretic techniques, a major drawback of this screening strategy is the almost identical retention time of several Hb variants. In particular, at least 18 Hb variants have been reported in the same retention window as HbA2, including HbE, the second most common ,-chain variant in humans after sickle cell trait. Recently, we evaluated the performance characteristics of an improved buffer formulation originally conceived for Hb variants separation procedures on the fully automated high-pressure liquid chromatography instrument Tosoh G7. At variance with other fully automated high-pressure liquid chromatography analyzers, the elution pattern on the G7 in subjects heterozygous for HbE is characterized by the presence of four suggestive peaks (HbF, HbA, HbA2 and HbE), confirming the effective separation of HbE from HbA2. Because of its potential value in the diagnosis of the thalassaemia syndromes, the effective separation of HbA2 from HbE can provide clinical laboratories with a valuable information for the diagnostic reasoning. [source]

Transcription-mediated amplification linked to line probe assay as a routine tool for HCV typing in clinical laboratories,

JOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 5 2007
R.S. Ross
Abstract Typing of hepatitis C virus (HCV) isolates is currently a prerequisite for adequate tailoring of antiviral combination therapy. In many diagnostic laboratories, there seems to be a tendency toward convenient and time-saving procedures utilizing amplification products, which are already available from preceding qualitative or quantitative HCV ribonucleic acid (RNA) assays. In this context, we evaluated the performance characteristics of a combination of techniques, i.e., transcription-mediated amplification-line probe assay (TMA-LiPA), which links highly sensitive TMA of HCV RNA to the VERSANT HCV Genotype Assay (version 1). A total of 100 clinical samples were genotyped by TMA-LiPA. The obtained results were compared to those recorded by the original, nested reverse transcription (RT)-polymerase chain reaction (PCR)-based VERSANT assay, the core-related GEN-ETI-K DEIA, and phylogenetic analyses of partial sequences from the HCV core and NS5B regions. TMA-LiPA assigned the correct genotype to all 100 HCV isolates. For subtyping of genotype 1 and 2 isolates, TMA-LiPA only showed discriminatory powers of 82% and 53%, respectively. Thus, TMA-LiPA in our hands turned out as a convenient and time-saving routine procedure for HCV typing which currently provides sufficient information for clinical purposes. Like all 5,untranslated region (UTR)-based assays, the technique is limited, however, in its potentials to resolve the complexity of existing HCV subtypes. J. Clin. Lab. Anal. 21:340,347, 2007. © 2007 Wiley-Liss, Inc. [source]

Switching from HPLC/UV to MEIA for whole blood sirolimus quantitation: comparison of methods

JOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 6 2006
Luigi Alberto Pini
Abstract Sirolimus is a immunosuppressive agent for renal transplant recipients. Monitoring of whole blood sirolimus concentration is necessary in order to improve clinical outcomes. An increasing number of clinical laboratories (4,14% during 2005) are using microparticle enzyme immunoassay (MEIA) for sirolimus quantitation but previous reports indicated a high variability, with a mean difference of 17% for MEIA method vs. high-performance liquid chromatography/ultraviolet (HPLC/UV). This study was aimed at comparing the reliability of MEIA with the HPLC/UV method. Blood samples from transplant patients were processed using both HPLC/UV and MEIA assays. Comparison and Bland-Altman plots, as well as regression analysis and paired t -test were used to compare results of the assays. Concentrations were stratified into three groups and used to investigate whether any observed difference between methods could be influenced by sirolimus concentration. Regression analysis yielded a coefficient of correlation R of 0.9756, the line of best fit being y=0.9832x+0.1976. The statistical analysis showed no difference between the two sets of experimental data. The average percentage difference between the two methods was found to be ,0.2±19.2%. On the basis of our present results, the tested MEIA assay is able to quantify sirolimus concentration with a clinically acceptable imprecision, similar to that of HPLC/UV method. J. Clin. Lab. Anal. 20:239,244, 2006. © 2006 Wiley-Liss, Inc. [source]

Negative interference of bilirubin and hemoglobin in the MEIA troponin I assay but not in the MEIA CK‐MB assay

JOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 2 2001
Amitava Dasgupta
Abstract Troponin I is a sensitive and specific marker for the diagnosis of myocardial infarction. Several commercially available immunoassays measure the concentration of troponin I in serum. The microparticle enzyme immunoassay (MEIA) for troponin I (Abbott Laboratories, Abbott Park, IL) is widely used in clinical laboratories, including our hospital laboratory. We studied the effect of bilirubin and hemolysis on the MEIA for troponin I and compared our assay with a newly available chemiluminescent assay (CLIA) for troponin I (Bayer Diagnostics, Tarrytown, NY). We also measured CK‐MB concentration using the MEIA CK‐MB assay. One serum pool was prepared by combining several specimens of one patient with elevated troponin I and with a diagnosis of myocardial infarction. Other serum pools were prepared by combining sera with similar troponin I values. All serum pools showed normal bilirubin concentrations and had no hemolysis. Then we supplemented aliquots of serum pools with various concentrations of bilirubin (5.0, 10.0, 15.0, and 20.0 mg/dL). After supplementation, troponin I concentrations were measured again using the MEIA and CLIA. We observed a statistically significant decrease in troponin I concentration in the presence of bilirubin with the MEIA. For example, in serum pool 1, the troponin I concentration was 16.3 (bilirubin: 0.8 mg/dL). In the presence of 5.0, 10.0, 15.0 and 20.0 mg/dL of added bilirubin, the cardiac troponin I concentrations were 13.9, 13.4, 13.3 and 13.0 ng/ml respectively. We observed similar negative interference of bilirubin in troponin I measurement by the MEIA in other pools. The troponin I value decreased slightly (not statistically significant) in one pool and did not change in two other pools in the presence of bilirubin when we measured troponin I concentration using the CLIA. Interestingly, bilirubin did not interfere with the MEIA CK‐MB assay. Moderate hemolysis did not have any effect on the troponin I assay using either the MEIA or CLIA. However, gross hemolysis (hemoglobin > 40 mg/dL) interfered with both assays for troponin I. J. Clin. Lab. Anal. 15:76–80, 2001. © 2001 Wiley‐Liss, Inc. [source]

Inorganic analysis of biological fluids using capillary electrophoresis

JOURNAL OF SEPARATION SCIENCE, JSS, Issue 11 2008
Andrei R. Timerbaev
Abstract This review article focuses on recent advances of CE in determination of inorganic species in biological fluids and covers the years of dedicated research in the field since 2001 when a previous similar review was published [1]. The most productive area, in which CE has distinctively progressed over the review period, encompasses assaying major inorganic anions and cations in blood serum and urine. Other applications include assessing less abundant analytes, e. g., heavy metals or seleno-compounds, and less abundant body fluids (saliva, sweat, etc.). Special emphasis is placed on developments in CE methodology that comprised modifications of separation and detection hardware and using specific electrolyte modifiers to enhance the resolution of a CE system. Significant progress in the application of in-line preconcentration methods in order to move CE ahead closer to trace analyte levels is also brought into focus. A series of tables detailing highly developed CE procedures and the analytical figures of merit accomplished are included. Finally discussed are further strategies for the method's expansion in the practice of biomedical and clinical laboratories where CE could likely acquire the status of a benchmark analytical technique. [source]

Performance of sequence analysis, INNO-LiPA line probe assays and AFFIGENE assays in the detection of hepatitis B virus polymerase and precore/core promoter mutations

JOURNAL OF VIRAL HEPATITIS, Issue 6 2006
A. Olivero
Summary., In this study, we compare results obtained by sequences analysis and commercial kits in the detection of hepatitis B virus (HBV) polymerase and precore (PC) and core promoter mutations. A total of 23 serum samples from lamivudine treated patients were tested for polymerase mutations by direct sequencing, INNO-LiPA HBV DR and AFFIGENE HBV DE/3TC. Full concordance among the three assays was observed in 63% of the total analysed codons. Concordant results were obtained between sequencing and LiPA in 80%, between sequencing and AFFIGENE in 73% and between LiPA and AFFIGENE in 74% of all tested codons. All discrepancies were observed in mixed population samples in which AFFIGENE and LiPA detected additional viral variants not revealed by sequence. In two patients, with serial samples, LiPA detected earlier than sequence and AFFIGENE an emerging mutate strain. PC and core promoter viral variants were detected in 28 serum samples collected from 14 HBV inactive carriers and from 14 hepatitis B patients with chronic liver disease. Direct sequencing, INNO-LiPA HBV PreCore and AFFIGENE HBV MUTANT VL 19 showed fully coincident results in 88% of tested positions. These findings showed that all assays evaluated were sensitive and accurate tools to analyse HBV genomic variability. Sequence analysis is essential to study new emerging mutations as LiPA and AFFIGENE assays are more easily useful in clinical laboratories to detect the appearance of well-characterized HBV variants. [source]

Liquid chromatography,tandem mass spectrometry applications in endocrinology

MASS SPECTROMETRY REVIEWS, Issue 3 2010
Mark M. Kushnir
Abstract Liquid chromatography,tandem mass spectrometry (LC,MS/MS) has been recognized as a primary methodology for the accurate analysis of endogenous steroid hormones in biological samples. This review focuses on the use of LC,MS/MS in clinical laboratories to assist with the diagnosis of diverse groups of endocrine and metabolic diseases. Described analytical methods use on-line and off-line sample preparation and analytical derivatization to enhance analytical sensitivity, specificity, and clinical utility. Advantages of LC,MS/MS as an analytical technique include high specificity, possibility to simultaneously measure multiple analytes, and the ability to assess the specificity of the analysis in every sample. All described analytical methods were extensively validated, utilized in routine diagnostic practice, and were applied in a number of clinical and epidemiological studies, including a study of the steroidogenesis in ovarian follicles. © 2009 Wiley Periodicals, Inc. Mass Spec Rev 29:480-502, 2010 [source]

Analytic validity of genetic tests to identify factor V Leiden and prothrombin G20210A,

AMERICAN JOURNAL OF HEMATOLOGY, Issue 4 2010
Ashkan Emadi
The objective of this study is to systematically review methods for detecting Factor V Leiden or prothrombin G20210A. English-language literature from MEDLINE®, EMBASE®, The Cochrane Library, the Cumulative Index to Nursing and Allied Health Literature, PsycInfo©, 2000-December 2008. Studies assessed methods for detection of these mutations in at least 10 human blood samples and reported concordance, discordance, or reproducibility. Two investigators abstracted data on the sample selection criteria, test operators, DNA extraction, experimental test, reference standard, commercial instruments, concordance rates, explanation of any discordance, and whether discordance resolved after repetition. We assessed strength of the evidence using the GRADE criteria. We reviewed 7,777 titles and included 66 articles. The majority of the reviewed studies used PCR-RFLP or AS-PCR as the reference standard. The studies demonstrated that commercially available and precommercial tests have high analytic validity with all having greater than 99% concordance with the reference standard. With a few exceptions, discordance resolved with repetition of the test, suggesting operator or administrative errors were responsible for the discordant results. In the quality assurance studies, greater than 98% of laboratories demonstrated high, even perfect, accuracy when asked to diagnose a sample with a known mutation. The majority of errors came from a limited number of laboratories. Although not all methods may be accurate, there is high-grade evidence that genetic tests for the detection of FVL and prothrombin G20210A have excellent analytic validity. There is high-grade evidence that most, but not all, clinical laboratories test for FVL and prothrombin G20210A accurately. Am. J. Hematol., 2010. © 2009 Wiley-Liss, Inc. [source]

ISO 9002 certification , expectations of the sponsor's auditor

QUALITY ASSURANCE JOURNAL, Issue 1 2002
Beat Widler
Abstract The value of ISO standards or rather the reliability of their application by clinical laboratories and CROs must be questioned. Results from audits performed by auditors overseeing ISO certification and maintenance do not necessarily provide full confidence in the ISO certification process to sponsors. Based on our sponsor-audits, we concluded that an ISO certification cannot substitute a systems' audit conducted by our own auditors against GCP and, where appropriate, GLP standards. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Let them fly or light them up: matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry and fluorescence in situ hybridization (FISH),

APMIS, Issue 11-12 2004
BIRGITTA SCHWEICKERT
This review focuses on clinical bacteriology and by and large does not cover the detection of fungi, viruses or parasites. It discusses two completely different but complementary approaches that may either supplement or replace classic culture-based bacteriology. The latter view may appear provocative in the light of the actual market penetration of molecular genetic testing in clinical bacteriology. Despite its elegance, high specificity and sensitivity, molecular genetic diagnostics has not yet reached the majority of clinical laboratories. The reasons for this are manifold: Many microbiologists and medical technologists are more familiar with classical microbiological methods than with molecular biology techniques. Culture-based methods still represent the work horse of everyday routine. The number of available FDA-approved molecular genetic tests is limited and external quality control is still under development. Finally, it appears difficult to incorporate genetic testing in the routine laboratory setting due to the limited number of samples received or the lack of appropriate resources. However, financial and time constraints, particularly in hospitals as a consequence of budget cuts and reduced length of stay, lead to a demand for significantly shorter turnaround times that cannot be met by culture-dependent diagnosis. As a consequence, smaller laboratories that do not have the technical and personal equipment required for molecular genetic amplification techniques may adopt alternative methods such as fluorescence in situ hybridization (FISH) that combines easy-to-perform molecular hybridization with microscopy, a technique familiar to every microbiologist. FISH is hence one of the technologies presented here. For large hospital or reference laboratories with a high sample volume requiring massive parallel high-throughput testing we discuss matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF) of nucleic acids, a technology that has evolved from the post-genome sequencing era, for high-throughput sequence variation analysis (1, 2). [source]

Development of the Capacity Necessary to Perform and Promote Knowledge Translation Research in Emergency Medicine

ACADEMIC EMERGENCY MEDICINE, Issue 11 2007
Peter S. Dayan MD
Knowledge translation (KT) research in emergency medicine (EM) is in its infancy, and few EM investigators have the skills needed to perform KT research. Furthermore, the capacity to perform such KT research is underdeveloped in the field of EM. This consensus group used an iterative process to set forth initial recommendations and suggest methods for the development of EM KT research capacity. We have emphasized the need to form sustainable linkages, particularly between EM researchers and KT scientists, and to educate EM researchers in KT research methods to help create and sustain a culture of KT in our field. EM KT researchers must also engage local and national organizations and stakeholders to fund and promote KT research. Finally, we see the need to further develop and support EM research networks, as these networks will be both the clinical laboratories in which to perform the KT research and the incubators for the development of EM KT research experts. [source]

Low-level glycopeptide resistance in methicillin-resistant Staphylococcus aureus and how to test it

CLINICAL MICROBIOLOGY AND INFECTION, Issue 2009
P. M. Hawkey
Abstract Vancomycin resistance in Staphylococcus aureus has emerged over the last ten years due to varying mechanisms and giving variable levels of resistance to vancomycin. The most resistant strains (fortunately rare) bear the vanA gene cluster and these are generally recognisable as MICs of vancomycin are usually found to be in the range 32-64mg/L. It should be noted that some automated systems have failed to detect these isolates. The much more commonly encountered GISA and hGISA vancomycin resistant strains of MRSA and methicillin sensitive Staph. aureus (MSSA) exhibit lower levels of resistance and difficulty is encountered in reliably defining and identifying these strains in clinical laboratories. No single completely reliable, convenient test either phonotypical genetic currently exists which can be readily applied in the clinical laboratory for the detection of hGISA/GISA. The population analysis profile (PAP) method is currently regarded as the reference method but is slow and tedious to perform on a large number of isolates. This enables the differentiation of hGISA and GISA from fully vancomycin sensitive strains. In the clinical laboratory the use of Meuller-Hinton agar with 5mg/L teicoplanin and a 10,L innoculum of MacFarland 0.5 incubated for 48h represents the most reliable and economical screening test. Further confirmation would be required using either macrodilution Etest methodology using an MIC , 8mg/L of vancomycin and/or teicoplanin as the cut off for hGISA or the newer GRD (glycopeptide resistance detection) strip. [source]

Evaluation of the Murex HIV Ag/Ab Combination assay when used with dried blood spots

CLINICAL MICROBIOLOGY AND INFECTION, Issue 11 2007
V. Lakshmi
Abstract This study evaluated the ability of the Murex HIV Ag/Ab Combination assay to detect human immunodeficiency virus (HIV) antibodies in 12 617 dried blood spots (DBSs) on filter paper. The assay had an overall sensitivity of 99.6% and a specificity of 99.9%. In view of its ability to detect p24 antigen and both HIV-1 and HIV-2 antibodies in samples collected in the form of DBSs, the Murex Ag/Ab Combination assay is suitable for use as a standard screening assay for seroprevalence studies, as well as for routine diagnostic use in clinical laboratories. [source]

Comparison of Laboratory Values Obtained by Phlebotomy versus Saline Lock Devices

ACADEMIC EMERGENCY MEDICINE, Issue 1 2007
Jill Corbo MD
Abstract Objectives To assess the utility of a peripheral saline lock device (SLD) as an alternative to a second venipuncture for obtaining selected blood samples. Methods This prospective study used a comparative design and was conducted in an urban emergency department (ED). Adult patients with an existing SLD in place who required serial phlebotomy were eligible for inclusion in the study. Each subject had blood samples obtained by venipuncture (control) with a Vacutainer adapter according to standard protocols. Within 5 minutes of obtaining the control samples, a sample was obtained from the patients' SLDs; a tourniquet was applied proximal to the intravenous line, a 5-mL waste portion was obtained, and a Vacutainer adapter was placed to draw specimens for testing. Each of the paired samples was analyzed for hematocrit, electrolytes, and cardiac enzymes. The Bland-Altman method was used to analyze the concordance between each pair of measurements. Paired t-tests for each of the eight laboratory tests were used to assess whether the values were statistically different from each other. The 95% limits of agreement around the mean differences were calculated. Differences between SLD aspirates and venipuncture aspirates also were compared with the federal regulatory standards that ensure reliable and accurate laboratory testing. Results Eighty-one patients were eligible for the study; in 73 (90.1%; 95% confidence interval [CI] = 81.5% to 95.6%) of the patients, the SLD could be aspirated for testing. The paired t-tests indicated that there were no statistically significant differences between the mean values of the two methods of testing. Of the 584 paired values analyzed, 35 (6.0%; 95% CI = 4.3% to 8.2%) exceeded the Bland-Altman limits of agreement, and 43 (7.4%; 95% CI = 5.4% to 9.8%) fell outside the acceptable range determined by the federal regulation of clinical laboratories. Of those values that exceeded the acceptable Bland-Altman limits of agreement, none would have resulted in clinical intervention. Conclusions Aspirating blood via an SLD is an acceptable method of obtaining serial laboratory values in a group of stable, consenting adult ED patients. [source]

Copeptin: A Biomarker of Cardiovascular and Renal Function

CONGESTIVE HEART FAILURE, Issue 2010
Nils G. Morgenthaler MD
Congest Heart Fail. 2010;16(4)(suppl 1):S37,S44. ©2010 Wiley Periodicals, Inc. Arginine vasopressin (AVP or antidiuretic hormone) is one of the key hormones in the human body responsible for a variety of cardiovascular and renal functions. It has so far escaped introduction into the routine clinical laboratory due to technical difficulties and preanalytical errors. Copeptin, the C-terminal part of the AVP precursor peptide, was found to be a stable and sensitive surrogate marker for AVP release. Copeptin behaves in a similar manner to mature AVP in the circulation, with respect to osmotic stimuli and hypotension. During the past years, copeptin measurement has been shown to be of interest in a variety of clinical indications, including cardiovascular diseases such as heart failure, myocardial infarction, and stroke. This review summarizes the recent progress on the diagnostic use of copeptin in cardiovascular and renal diseases and discusses the potential use of copeptin measurement in the context of therapeutic interventions with vasopressin receptor antagonists. [source]

Assessment of executive function in preschool-aged children

DEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 3 2005
Peter K. Isquith
Abstract Assessment of the overarching self-regulatory mechanisms, or executive functions, in any age group is challenging, in part due to the complexity of this domain, in part due to their dynamic essence, and in part due to the inextricable links between these central processes and the associated domain-specific processes, such as language, motor function, and attention, over which they preside. While much progress has been made in clinical assessment approaches for measuring executive functions in adults and to some extent in adolescents and school-aged children, the toolkit for the preschool evaluator remains sparse. The past decade, however, has seen a substantial increase in attention to executive functions in very young children from a developmental neuropsychological perspective. With this has come a necessity for better, more specific, and more internally valid performance measures, many of which are now described in the experimental literature. Few such tasks, however, have adequately demonstrated psychometric properties for clinical application. We present two performance tasks designed to tap selective aspects of executive function in preschoolers that are emerging from the experimental laboratory and hold promise of appropriate reliability and validity for the clinical laboratory. Performance tests alone, however, are insufficient to develop a comprehensive picture of a child's executive functioning. Thus, we present a rating scale of preschoolers' executive function in the everyday context, and advocate a model of executive function assessment that incorporates both controlled performance tasks that target specific aspects of executive function and parent/teacher ratings that target more global aspects of self-regulation in the everyday context. © 2005 Wiley-Liss, Inc. MRDD Research Reviews 2005;11:209,215. [source]

Classification of the Myoclonic Epilepsies

EPILEPSIA, Issue 2003
Ilo E. Leppik
Summary: The myoclonic epilepsies are a collection of syndromes in which myoclonic seizures are a prominent feature. Proper classification of a patient's syndrome is critical for appropriate treatment and prognosis. However, classification of such syndromes is often difficult because the terminology used to describe seizures can be confusing and inconsistent. Myoclonic epilepsy syndromes can be epileptic or nonepileptic and can also be divided into inherited and acquired forms. Progressive myoclonic epilepsy (PME) syndromes are the most severe of the myoclonic epilepsies. Diagnosis of PME syndromes on clinical grounds can be difficult, but advances in genetic testing have made diagnoses more accurate. Some other benign myoclonic epilepsy syndromes also have identified gene markers, which can aid in diagnosis. To accurately classify a patient's epilepsy syndrome, clinicians should use all available clinical laboratory tools appropriately. Improved accuracy of diagnosis for patients with myoclonic epilepsies should lead to more dependable prognoses and more effective treatment. [source]

Mutational spectrum of the NF2 gene: a meta-analysis of 12 years of research and diagnostic laboratory findings,,

HUMAN MUTATION, Issue 1 2007
Iris Ahronowitz
Abstract The NF2 tumor suppressor gene on chromosome 22 is a member of the protein 4.1 family of cytoskeletal elements. A number of single- and multiple-tumor phenotypes have been linked to alterations of NF2 since its characterization in 1993. We present a meta-analysis of 967 constitutional and somatic NF2 alterations from 93 published reports, along with 59 additional unpublished events identified in our laboratory and 115 alterations identified in clinical samples submitted to the Massachusetts General Hospital (MGH) Neurogenetics DNA Diagnostic Laboratory. In total, these sources defined 1,070 small genetic changes detected primarily by exon scanning, 42 intragenic changes of one whole exon or larger, and 29 whole gene deletions and gross chromosomal rearrangements. Constitutional single-exon events (N=422) were significantly more likely to be nonsense or splice site changes than somatic events (N=533), which favored frameshift changes (,2 test; P<0.001). Somatic events also differed markedly between tumors of different pathology, most significantly in the tendency of somatic events in meningiomas to lie within the 5, FERM domain of the transcript (Fisher's exact test; P<0.01 in comparison to schwannomas) with a complete absence of mutations in exons 14 and 15. There was no statistically significant difference in mutation type or exon distribution between published constitutional events and those found by the clinical laboratory. Less than 10% of all published and unpublished small alterations are nontruncating (N=63) and these changes are clustered in exons 2 and 3, suggesting that this region may be especially crucial to tumor suppressor activity in the protein. Hum Mutat 28(1), 1,12, 2007. Published 2006 Wiley-Liss, Inc. [source]

Comparability of the results of PT,INR with local MNPT and APTTR with MNAPTT on different coagulation analyzers in China

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 3 2009
L. PENG
Summary The prothrombin time (PT), International normalized ratio (INR) and activated partial thromboplastin time (APTT) are the most used coagulation tests in China, where more than one type of automated coagulation analyzer is often used in the clinical laboratory. The PT,INR results of 109 samples were compared with local mean normal PT (MNPT) and APTT ratio (APTTR) with mean normal APTT (MNAPTT) on two different coagulation analyzers in the same laboratory. The two different coagulation analyzers showed no significant difference (P > 0.05) in PT and INR determination, but there was a significant difference (P < 0.01) for APTT. The INR with local MNPT and APTTR with MNAPTT, obtained with the ACL Futura and CA 510, showed much better agreement; 98.8% (82/83) of bias for INR with local MNPT was less than 15% compared with 90.4% (75/83) of bias for INR; and 100% of bias for APTTR (62/62) was less than 15% compared with only 6.5% (4/62) of bias for APTT. Meanwhile, there was no significant difference (P = 0.865) for APTTR with MNAPTT compared with APTT (P = 0.002) between the ACL Futura and CA 510. In conclusion, these analyzers showed very poor agreement for both the PT and APTT, but the calculation of ratios significantly improved agreement. [source]

Simultaneous detection and differentiation of human polyomaviruses JC and BK by a rapid and sensitive PCR-ELAHA assay and a survey of the JCV subtypes within an Australian population

JOURNAL OF MEDICAL VIROLOGY, Issue 3 2004
David M. Whiley
Abstract Human polyomaviruses JCV and BKV can cause several clinical manifestations in immunocompromised hosts, including progressive multifocal leukoencephalopathy (PML) and haemorrhagic cystitis. Molecular detection by polymerase chain reaction (PCR) is recognised as a sensitive and specific method for detecting human polyomaviruses in clinical samples. In this study, we developed a PCR assay using a single primer pair to amplify a segment of the VP1 gene of JCV and BKV. An enzyme linked amplicon hybridisation assay (ELAHA) using species-specific biotinylated oligonucleotide probes was used to differentiate between JCV and BKV. This assay (VP1-PCR-ELAHA) was evaluated and compared to a PCR assay targeting the human polyomavirus T antigen gene (pol - PCR). DNA sequencing was used to confirm the polyomavirus species identified by the VP1-PCR-ELAHA and to determine the subtype of each JCV isolate. A total of 297 urine specimens were tested and human polyomavirus was detected in 105 specimens (35.4%) by both PCR assays. The differentiation of JCV and BKV by the VP1-PCR-ELAHA showed good agreement with the results of DNA sequencing. Further, DNA sequencing of the JCV positive specimens showed the most prevalent JCV subtype in our cohort was 2a (27%) followed by 1b (20%), 1a (15%), 2c (14%), 4 (14%) and 2b (10%). The results of this study show that the VP1-PCR-ELAHA is a sensitive, specific and rapid method for detecting and differentiating human polyomaviruses JC and BK and is highly suitable for routine use in the clinical laboratory. J. Med. Virol. 72:467,472, 2004. © 2004 Wiley-Liss, Inc. [source]

Hypo-osmotic swelling test and unexplained repeat early pregnancy loss

JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 1 2010
Sudhindra M. Bhattacharya
Abstract Aim:, To study the relationship of various sperm characteristics and hypo-osmotic swelling test (HOS test) with repeat unexplained early pregnancy loss. Methods:, Semen samples from husbands of 74 couples with a history of repeat early pregnancy loss (group A) were analyzed according to World Health Organization criteria, and a HOS test was performed in each case. Semen samples from 65 husbands with proven fertility (group B) were also studied for comparison. Results:, No statistically significant differences were noted in the age of the husbands, sperm concentration, sperm morphology and percent motile sperm between groups A and B. The mean HOS test scores of the two groups were significantly different (group A: 60.4%; group B: 76.9%; P = 0.01 [normal value: >60%]). In group A, 33.8% of cases (25/74) and in group B, 12.3% of cases (8/65) showed low HOS test scores. Conclusion:, The sperm HOS test may be helpful to screen for any paternal factor associated with repeat embryonic or early fetal loss and in a resource-poor setting, and may be utilized in any clinical laboratory. [source]

Safety profile of dexlansoprazole MR, a proton pump inhibitor with a novel dual delayed release formulation: global clinical trial experience

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 10 2009
D. A. PEURA
Summary Background, Dexlansoprazole MR is a dual delayed release formulation of dexlansoprazole, an enantiomer of lansoprazole. Aim, To assess safety of dexlansoprazole MR in phase 3 clinical trials. Methods, Data from 4270 patients receiving dexlansoprazole MR 30 mg (n = 455), 60 mg (n = 2311) or 90 mg (n = 1864); lansoprazole 30 mg (n = 1363); or placebo (n = 896) in six randomized controlled trials and a 12-month safety study were pooled. Safety was assessed via adverse events, vital signs, electrocardiograms, clinical laboratory results and gastric biopsies. Adverse events were summarized per 100 patient-months of exposure to account for imbalances in study drug exposure. Results, The number of patients with ,1 treatment-emergent adverse event per 100 patient-months was higher in placebo (24.49) and lansoprazole (21.06) groups than in any dexlansoprazole MR (15.64,18.75) group. Fewer patients receiving dexlansoprazole MR discontinued therapy because of an adverse event (P , 0.05 vs. placebo). Seven patients died of events considered unrelated to study drug. Mean serum gastrin rose in all groups except placebo; increases were not dose-related. No clinically concerning trends were seen in gastric biopsy results. Endocrine cell hyperplasia, dysplasia and neoplasia were not observed. Conclusion, Dexlansoprazole MR 30,90 mg has a safety profile comparable to that of lansoprazole. [source]

Comparative evaluation of Candi Select test and conventional methods for identification of Candida albicans in routine clinical isolates

MYCOSES, Issue 3-4 2002
S. Foongladda
Candida albicans; Identifizierung; Candi Select- Test; Bewertung. Summary. The Candi Select test (Sanofi Diagnostics, Pasteur, Marnes-La-Coquette, France) is a new yeast-selective medium for the identification of Candida albicans in the clinical laboratory. The performance of this test was compared with the conventional methods of chlamydospore formation, germ tube formation and carbohydrate fermentation. Four hundred and twenty clinical yeast isolates from 412 fresh clinical specimens, including 283 C. albicans, 59 C. tropicalis, 39 Trichosporon spp., 19 C. glabrata, 11 Cryptococcus neoformans and 9 other yeasts, were evaluated. Colonies of C. albicans produced a blue-green colour on the Candi Select media which could be distinguished from the other yeasts with the naked eye within 24,48 h. The sensitivity and specificity of the Candi Select test for the identification of C. albicans were 99.65% and 97.08%, respectively. The blue-green colonies of C. albicans were easy to identify and recognize in mixed cultures and did not need detailed microscopic examination. Zusammenfassung., Der Candi Select-Test (Sanofi Diagnostics Pasteur, Marnes-La-Coquette, Frankreich) ist ein neuer selektiver Nährboden für die Identifizierung von Candida albicans im klinischen Labor. Die neue Methode wurde mit den konventionellen Methoden der Chlamydosporenbildung, der Keimschlauchbildung und der Kohlenhydrat-Gärung verglichen. Vierhundertzwanzig Hefeisolate, nämlich 283 C. albicans, 59 Candida tropicalis, 39 Trichosporon spp., 19 Candida glabrata, 11 Cryptococcus neoformans und 9 andere Hefen, isoliert aus 412 frischen klinischen Untersuchungsproben, wurden mit allen Methoden untersucht. Mit blossem Auge erkennbar, unterschieden sich innerhalb von 24,48 Stunden die blau-grünen Farbkolonien von C. albicans von allen anderen Hefen auf dem Candi Select Nährboden. Sensitivität und Spezifizität des Candi Select Tests für die Identifizierung von C. albicans betrugen 99.65% und 97.08%. Die blau-grünen Farbkolonien von C. albicans waren in den Mischkulturen leicht zu identifizieren, eine mikroskopische Untersuchung erübrigt sich daher. [source]

Iridium Oxide Film-Enhanced Impedance Immunosensor for Rapid Detection of Carcinoembyronic Antigen

CHINESE JOURNAL OF CHEMISTRY, Issue 9 2007
Yan-Jun Ding
Abstract A simple, rapid and sensitive impedance immunosensor based on iridium oxide (IrOx) thin film for the detection of carcinoembyronic antigen (CEA) in human sera has been proposed. Gold electrode was electrochemically modified with IrOx thin film and simultaneously functionalized with protein A (PA) to bind anti-CEA antibodies in an orientated way. It has been found that the antibody loading amount was dependent on the PA concentration and the deposition time of IrOx matrix. Under the optimized experimental conditions, the electron transfer resistances obtained were linearly related to the CEA concentration ranging from 36.2 to 460.0 ng/mL, with a detection limit of 28.0 ng/mL. Analytical results of clinical samples from cancer patients show that the proposed immunoassay is reasonably comparable with the chemiluminescence immunoassay (CLIA), indicating the feasibility of using the proposed method for CEA immunoassay in clinical laboratory. [source]