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PubMed2002

Gender differences in C-reactive protein concentrations-confirmation with two sensitive methods.

Two new automated, highly sensitive methods for the measurement of C-reactive protein (CRP) were compared using blood samples from active and retired health care workers (116 males, 114 females). The regression equation was y=1.115x-0.0267 forthe Kamiya K assay immunoturbidimetric method (x) vs. the Behring BNII nephelometric method (y) with medians (IQR) of 0.156 (0.081 to 0.276) and 0.150 (0.060 to 0.240) mg/dl, respectively. Significant differences in hsCRP values between males and females were observed (p=0.013 and p=0.0018 for Behring and Kamiya methods, respectively). This gender difference in CRP levels was confirmed by analysis of serum samples from 1,114 individuals (639 males and 475 females) obtained through Mayo Medical Laboratories reference services, which represents participants from across the United States. The gender difference, which was confirmed (p<0.0001), was independent of age differences as assessed by multiple regression analysis. The observed gender differences have important implications for the establishment of cut-off points for cardiovascular risk stratification.

Adult↗
PubMed2002

Reference values for a heterogeneous ferritin assay and traceability to the 3rd International Recombinant Standard for Ferritin (NIBSC code 94/572).

Reference values for Ferritin Flex on the Dimension RxL analyzer calibrated against the 3rd International Standard for Ferritin (recombinant) and N-Latex Ferritin on the BNA II nephelometer calibrated against the 2nd International Standard for Ferritin (spleen) both from Dade Behring (Marburg, Germany) were established (77 men and 182 women). Exclusion criteria were iron deficiency or iron deficiency anemia, inflammation, liver disease, malignancy, and other hematological or chronic disorders. The reference values (5.0th-95th percentiles) were as follow: for N-Latex Ferritin - men, 12-399 microg/l; women <50 years, 11-102 microg/l and women > or =50 years, 17-219 microg/l; for Ferritin Flex - men, 14-415 microg/l; women <50 years, 11-111 microg/l and women > or =50 years, 22-224 microg/l. Both assays correlated very closely with each other (r=0.993). The linearity was acceptable down to 2 microg/l for the Ferritin Flex method, but only down to 15 microg/l for the N-Latex Ferritin assay. The mean recovery of the 3rd International Standard by N-Latex Ferritin and Ferritin Flex was comparable (approximately 80%). We conclude that the new Ferritin Flex assay, which is based on the new 3rd International Standard, should be used for ferritin measurement in the routine medical laboratories in the future.

Adult↗
PubMed2002

Evaluation of uncertainty of measurement in routine clinical chemistry--applications to determination of the substance concentration of calcium and glucose in serum.

We studied the uncertainty of measurement for the calcium and glucose (amount of) substance concentrations in serum. The evaluation follows a four-step procedure, which complies with the ISO document Guide to the Expression of Uncertainty in Measurement (GUM). The applications were chosen to represent commonly used measuring systems in medical laboratories. The uncertainty components are quantified using observations of the measuring system, and information from calibration certificates, instrument specifications and literature. The evaluation focuses on the measurement step but empirical terms are used to illustrate how the pre-analytical phase and patient-related issues can be accounted for. The software GUM Workbench was used to facilitate calculations and to visualize the importance of each uncertainty component. The combined standard uncertainties (u(c)) for the measurands were < or =2% including the pre-analytical uncertainty sources. The patient-related source is discussed in relation to clinician's diagnosis and decision-making. The evaluation, as carried out here for calcium and glucose substance concentration measurements, can easily be applied to many other measurands in clinical chemistry. This work emphasizes that the internal quality control can provide much of the information needed in the uncertainty evaluation, and that external quality assessment (EQA) schemes are important in the control of the uncertainty evaluated by the individual laboratories. Due to statistical and metrological limitations routine EQA schemes should themselves not be used as a means of uncertainty evaluation.

Bias↗
PubMed2004

Guidelines for blood smear preparation and staining procedure for setting up an external quality assessment scheme for blood smear interpretation. Part I: Control material.

Blood smear analysis is a well known technique in medical laboratories. Clinical relevance of this analysis and its interpretation are very important. Consequently, monitoring of laboratory performance by an external quality assessment scheme is strongly recommended. Most starting external quality organizers set up a scheme for clinical chemistry. Due to a lack of guidance documents, many organizers are reluctant to offer a hematology scheme. This article aims to be a very practical guidance document for external quality assessment organizers for the set up of blood smear schemes.

Chemistry, Clinical↗
PubMed2006

Laboratory network of excellence: enhancing patient safety and service effectiveness.

Clinical laboratories have undergone major changes due to technological progress and economic pressure. While costs of laboratory testing continue to be the dominant issue within the healthcare service worldwide, quality, effectiveness and impact on outcomes are also emerging as critical value-added features. Five Italian laboratories are therefore promoting a network of excellence by investigating markers of effectiveness of laboratory services and sharing their experience of using them in clinical practice. In the present study we report preliminary data on indicators of quality in all phases of the so-called total testing process, the key to evaluating all phases of the total testing process, including the appropriateness of test requests and data interpretation. Initial findings in evaluating pre-analytical causes of specimen rejection in three different laboratories and the effects of introducing three laboratory clinical guidelines are reported. These data should stimulate debate in the scientific community and encourage more clinical laboratories to use the same indicators to improve clinical effectiveness and clinical outcomes within the healthcare service.

Clinical Laboratory Techniques↗
PubMed2006

Guidelines for setting up an external quality assessment scheme for blood smear interpretation. Part II: survey preparation, statistical evaluation and reporting.

Blood smear analysis is a well-known technique in medical laboratories. The clinical relevance of this analysis and its interpretation are very important. Consequently, monitoring of laboratory performance by an external quality assessment scheme is strongly recommended. This article represents a very practical guidance document for External Quality Assessment Scheme (EQAS) organizers for setting up blood smear schemes. In the first part of the guidelines, the Hematology Working Group of the European External Committee for External Quality Assurance Programmes in Laboratory Medicine (EQALM) published practical information for the preparation of blood smears for use in an EQAS. Part II focuses on aspects such as survey preparation, statistical evaluation and reporting, and describes particular details for organizing blood morphology EQA surveys by means of virtual microscopy.

Blood Stains↗
PubMed2004

Long-term persistence of chromosome aberrations in uranium miners.

Chromosome aberration analyses were performed on blood samples from 165 active underground uranium miners between 1981 and 1985. After decommissioning the mine in 1997 chromosome aberration analyses were also included in the medical laboratory investigations of health conditions of 141 subjects between 1998 and 2002 within the framework of a follow-up-study. The numerical data are presented as functions of the exposure categories expressed in working level month up to 600. In the active groups the dicentric level was 7 to 12 times higher than in the unexposed population, the acentrics also higher with more than an order of magnitude, the frequency of total aberrations--including dicentrics, acentrics, rings, deletions, minits and numerical aberrations, i.e. both chromatid and chromosome type of aberrations were also well above the control level. In the group of former uranium miners although there were slight decreases in the dicentrics after 8 to 25 yr, the values were not significantly different from the values of active miners. The frequency of deletions was also maintained in the post-mining period. The frequency of acentrics, however, decreased significantly, but even the lowest values remained 2-3 times higher than the values in the unexposed population.The possibility is suggested that for the long-term persistence of cytogenetic alterations the permanent production and presence of clastogenic factors might be responsible. The comparison of the two datasets suggest a long-term persistence of cytogenetic alterations above the population average values in a large fraction of persons investigated.

Adult↗
PubMedDate not supplied

Implementation and evaluation of a national external quality control program for cervical cytology in Mexico.

OBJECTIVE: To evaluate cytology laboratories and the performance of cytotechnologists for establishing efficient external quality control for Mexico's National Program for the Prevention and Control of Cervical Cancer. MATERIAL AND METHODS: During January and February 1998, an onsite evaluation of all cytology laboratories of the Ministry of Health found that only 70% of the microscopes were in adequate working conditions, reagents were out of date, and working conditions were sub-optimal. A program for external quality control based on proficiency testing was established for cytotechnologists. Fifty slide sets with 20 Papanicolaou slides and 10 photographic slides were prepared. The sets were given to the cytotechnologists for evaluation and again one year later by courier. RESULTS: Twenty-one percent of microscopes were repaired and 9% replaced; reagents were distributed and laboratory facilities improved. Only 16% of cytotechnologists passed the initial proficiency test. Cytotechnologists received a refresher training course: one year later 67% of them passed the proficiency test. To ascertain that each slide was correctly diagnosed, 41 sets were rescreened by expert cytopathologists or cytologists and their diagnoses compared to the original ones. Thirty-seven sets had 86% to 96% concordance. CONCLUSIONS: This new system for external quality control of cervical cytology allowed the opportune and reliable evaluation of the performance of cytotechnologists.

Diagnostic Errors↗
PubMed2004

[The Liver Diseases Program of the Hospital Santa Casa de Misericórdia do Pará--infrastructure and clinical epidemiology in 10 years of attendance].

The Liver Diseases Program of the Hospital Santa Casa de Misericordia do Pará was create because of the need to attend patients with liver diseases of the Amazônia area, taking as priority to attend with quality, diagnosis of aetiologies, clinical following and specific treatment. This study aim to describe dates related to epidemiology, aetiologics agents and histopathologic analysis. One thousand sixty nine patients were evaluated through medical, laboratory, endoscopic, ultrasound or computerized tomography and histopathologic examination. Nine hundred thirty five (63.6%) patients within 1469 patients were diagnose as chronic liver disease. The average age was 50 year, 666 (71.2%) were male, and the most patients lived in Belem, State of Pará. The aetiologic agents most prevail were alcoholism (53.7%) and viral hepatitis (39.1%). Hepatic biopsy were done in 403 (43.1%) within the 935 patients and the results showed chronic hepatitis (34%) and chirrosis (34%). In summary the chronic liver disease in the amazon region is more prevail in male than female, the alcoholism is the principal aetiologie, and the most of these cases were diagnose in the severe phase.

Alcoholism↗
PubMed2003

Evaluation of haematology analyzer CELL-DYN 3700 SL.

Research on the parameters of full blood count and differential white blood count is included in the program of all medical laboratories of primary, secondary and tertiary health care levels. Today, all haematological tests are exclusively performed on the haematology analyzers. Automation of haematology laboratories is a result of the huge requires for haematological test performing, timely issuing of the haematological findings, and possibility of the usage of modern techniques. This work is an evaluation of laser haematology analyzer Cell-Dyn 3700 SL. It investigates the reliability of test results throughout the following parameters: precision, accuracy, sensitivity and specificity of determination methods. It also explores the influence of sample transferring and correlation with haematology analyzer MAXM Retti. Haematology parameters that have been investigated are: white blood cell (WBC), neutrophils (NEU), lymphocytes (LXM), monocytes (MONO), eosinophils (EOS), basophils (BASO), red blood cells (RBC), haemoglobin (HGB), haematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCHC) red cell distribution width (RDW), platelet (PLT), mean platelet volume (MPV), plateletocrit (PCT), and platelet distribution width (PDW). The results confirms that precision of analyzer fulfils the reproducibility of testing parameters: WBC, RBC, HGB, MCV, MCH, MCHC, and PLT. Correlation coefficient values (r) gained throughout the statistical analysis, that is linear regression results obtained throughout the comparison of two analyzers are adequate except for MCHC (r = 0.64), what is in accordance with literature data. Accuracy is tested by haematology analyzer method and microscopic differentiating method. Correlation coefficient results for granulocytes, lymphocytes and monocytes point the accuracy of methods. Sensitivity and specificity parameters fulfil the analytical criteria. It is confirmed that haematology analyzer Cell-Dyn 3700 SL is reliable for the determination of full blood count in everyday work. Analyzer and its program for differential white blood count can be used for the research and separation of normal and pathological blood counts with addition of microscopic methods confirming distribution or morphologic changes of leukocytes.

Journal Article↗
PubMed1998

An overview of the roles and structure of international high-security veterinary laboratories for infectious animal diseases.

The unique structure, role and operations of government high-security (HS) laboratories which work on animal diseases are described, with particular reference to the laboratories of nine countries. High-security laboratories provide cost-effective insurance against catastrophic losses which could occur following exotic disease outbreaks. The importance of these laboratories is reflected in the fact that several new laboratories have recently been constructed at considerable expense and older facilities have undergone major renovations. Biosecurity is fundamental to the operation of high-security laboratories, so good facility design and microbiological security practices are very important. High-security laboratories conduct exotic disease diagnosis, certification and surveillance, and also perform research into virology, disease pathogenesis and improvements to diagnostic tests and vaccines. The mandate of these laboratories includes the training of veterinarians in the recognition of exotic diseases. One extremely important role is the provision of expert advice on exotic diseases and participation (both nationally and internationally) in policy decisions regarding animal disease issues.

Animals↗
PubMed1998

National and international veterinary reference laboratories for infectious diseases.

Reference laboratories play an increasingly important role in the harmonisation of laboratory diagnostic tests and the standardisation of veterinary vaccines. This is particularly important in building confidence between international trading partners. The authors review aspects of the organisation, designation and support of reference laboratories for infectious diseases of animals and discuss the principal activities which such laboratories would normally perform. These activities include advice and consultancy, publications and communication, training, research, disease surveillance, maintenance of culture collections, evaluation of reference methods, preparation of reference materials and organisation of inter-laboratory comparisons.

Animals↗
PubMed1998

Central or national veterinary diagnostic laboratories.

Information on laboratory organisational structure and roles was gathered from twenty-four national veterinary diagnostic laboratories around the world. This information was used to develop an overview of the organisation and roles of the national veterinary diagnostic laboratory. In addition, the national diagnostic laboratory for the United States of America (the National Veterinary Services Laboratories) was used as an example to provide more information on the activities of such a laboratory. The survey revealed great variation in organisation and structure among the twenty-four laboratories. A few have only one facility, others function at multiple locations, and all have different supervisory reporting systems. However, these laboratories all form a significant part of the national veterinary infrastructure. All of the laboratories contacted in the survey report to (or are at least partially under the direction of) the Chief Veterinary Officer or another senior animal health official, and most report to the Ministry of Agriculture. The national veterinary diagnostic laboratories have similar roles, and are all responsible for foreign animal disease diagnosis and for providing support to national disease eradication or control programmes. Most also play an active role in import and export testing, either performing the tests themselves or developing a quality assurance programme for other laboratories that perform the testing. In addition, the national veterinary diagnostic laboratories usually undertake research and provide training, consultation, disease surveillance information and, in some cases, vaccine evaluation.

Animal Diseases↗
PubMed1998

Quality assurance in veterinary diagnostic laboratories.

The authors discuss the responsibility of veterinary diagnostic laboratories as suppliers of analytical data for tests on animals and animal products. The guarantee of the quality of analytical data is a basic quality requirement for veterinary certification. It is therefore important for the laboratory to adopt operational quality assurance standards which are recognised internationally. The management and quality assurance criteria contained in the International Standardisation Organisation/International Electrotechnical Commission Guide 25, or in directives or guidelines established by international organisations such as the Office International des Epizooties and the Codex Alimentarius of the Food and Agriculture Organisation, are reviewed. These documents provide procedures for adopting the principles of quality assurance in order to acquire the recognition of competence to execute the laboratory tests required for national and international veterinary certification.

Animals↗
PubMed1998

Veterinary diagnostic laboratories in developing countries: the challenge of credibility.

The problems facing veterinary diagnostic laboratories in developing countries range from simple problems, such as limited funds to keep good personnel or obtain equipment, supplies, reagents or training, to the more complex problems of designing and executing appropriate sample collection schemes for disease surveillance of evaluating the performance characteristics of a new diagnostic assay. While many developing countries are addressing these problems independently and a number of international and national organisations provide various forms of external support, the Office International des Epizooties (OIE) must continue in its critical role to provide guidelines for the most appropriate diagnostic assays for trade purposes and the development of the primary reference reagents for these assays. In addition, the OIE should take the lead in development of quality management guidelines for veterinary diagnostic testing laboratories. Without these guidelines and standards, diagnostic laboratories in developing countries will have difficulty in gaining the credibility necessary to help improve the positions of their countries in the international trade of livestock and livestock commodities.

Animal Diseases↗
PubMed1998

District, state or regional veterinary diagnostic laboratories.

The district, regional or state laboratory is the local laboratory to which veterinarian practitioners usually submit samples, and consequently these laboratories are usually the first to observe a suspected disease problem. In most countries, these laboratories are under the jurisdiction of the State or region in which they are located. In the United States of America (USA), most veterinary diagnostic laboratories are State-associated and operate under the aegis of either the State Department of Agriculture or a university. The national laboratory provides reference assistance to the State laboratories. In the USA, the national Laboratory (the National Veterinary Services Laboratories) acts as a consultant to confirm difficult diagnoses and administer performance tests for State-associated laboratories. District, state or regional laboratories need to share information regarding technological advances in diagnostic procedures. This need was met in the USA by the formation of the American Association of Veterinary Laboratory Diagnosticians (AAVLD) in the late 1950s. Another requirement of district, state or regional diagnostic laboratories is a method to confirm quality assurance, which was fulfilled in the USA by an accreditation programme established through the AAVLD. The Accreditation Committee evaluates laboratories (on request) in terms of organisation, personnel, physical facilities and equipment, records, finance and budget. Those laboratories which meet the standards as established in the 'Essential Requirements for Accreditation' are given accreditation status, which indicates that they have the expertise and facilities to perform tests on food-producing animals for shipment in national or international commerce and on companion, laboratory or zoo animals. While confidentiality of test records is most important, it is becoming necessary to release certain types of animal disease test information if a country is to participate in the exportation of animals and animal products. As district, state and regional laboratories operate under many different administrative entities (i.e., universities, State governments and the Federal government), various checks at different administrative levels provide safeguards and reduce the possibility of faulty disease reporting.

Accreditation↗