Developing and expanding contributions of the global laboratory network for poliomyelitis eradication, 1997-1999. (41/1696)

In 1988, the World Health Assembly resolved to eradicate poliomyelitis globally by 2000. Substantial progress toward achieving this goal has been reported from all countries where polio is endemic, and three regions of the World Health Organization (WHO) (American Region, European Region, and Western Pacific Region) appear to be free of indigenous wild poliovirus transmission. One key strategy for polio eradication is establishing sensitive surveillance systems for polio (through notification of acute flaccid paralysis [AFP] cases) and poliovirus. To ensure that specimens from AFP cases undergo appropriate processing for viral isolation, WHO has established a global laboratory network. This report describes the proficiency of the network and provides updates on structure, accreditation, performance, expanding activities, and future plans.  (+info)

Evaluation of the Sirscan automated zone reader in a clinical microbiology laboratory. (42/1696)

We compared readings of Kirby-Bauer plates by the Sirscan, an automated image analyzer that measures zone diameters, to those of experienced clinical microbiologists measuring zones with a hand-held caliper interfaced to a computer and with a ruler. To read plates of Escherichia coli, Morganella morganii, and Pseudomonas aeruginosa containing 12 antibiotic disks the Sirscan took 11 s; technologists took 28 s by caliper and 39 s by ruler. Reading times of four different technologists ranged from 22 to 44 s with the caliper and 10 to 12 s with Sirscan. Upon repeated testing zone size variation rarely exceeded 3 mm by caliper and 1 mm by Sirscan. Over a 4-month period, 368 clinical isolates were tested prospectively by both methods in the Clinical Microbiology Laboratory of the Miriam Hospital. There was good correlation of zone sizes for most antibiotics, but Sirscan zone diameter measurements tended to be 3 to 5 mm larger than caliper readings for ciprofloxacin, norfloxacin, aztreonam, erythromycin, clindamycin, and trimethoprim-sulfamethoxazole. Very major errors (resistant by caliper and susceptible by Sirscan) occurred with 10 of 3,770 readings (0.3%), mainly where breakpoint criteria lacked an intermediate zone. They occurred in testing staphylococci with amoxicillin-clavulanate (5 of 127 isolates, 3.9%), pseudomonas with piperacillin (1 of 28, 3.6%), coagulase-negative staphylococci with oxacillin (2 of 74, 2.7%), gram-negative bacilli with cefuroxime (1 of 209, 0.5%), and mixed species with trimethoprim-sulfamethoxazole (1 of 366, 0.3%). The Sirscan zone reader facilitates accurate, fully quantitative susceptibility testing in clinical microbiology laboratories.  (+info)

Applications of flow cytometry to clinical microbiology. (43/1696)

Classical microbiology techniques are relatively slow in comparison to other analytical techniques, in many cases due to the need to culture the microorganisms. Furthermore, classical approaches are difficult with unculturable microorganisms. More recently, the emergence of molecular biology techniques, particularly those on antibodies and nucleic acid probes combined with amplification techniques, has provided speediness and specificity to microbiological diagnosis. Flow cytometry (FCM) allows single- or multiple-microbe detection in clinical samples in an easy, reliable, and fast way. Microbes can be identified on the basis of their peculiar cytometric parameters or by means of certain fluorochromes that can be used either independently or bound to specific antibodies or oligonucleotides. FCM has permitted the development of quantitative procedures to assess antimicrobial susceptibility and drug cytotoxicity in a rapid, accurate, and highly reproducible way. Furthermore, this technique allows the monitoring of in vitro antimicrobial activity and of antimicrobial treatments ex vivo. The most outstanding contribution of FCM is the possibility of detecting the presence of heterogeneous populations with different responses to antimicrobial treatments. Despite these advantages, the application of FCM in clinical microbiology is not yet widespread, probably due to the lack of access to flow cytometers or the lack of knowledge about the potential of this technique. One of the goals of this review is to attempt to mitigate this latter circumstance. We are convinced that in the near future, the availability of commercial kits should increase the use of this technique in the clinical microbiology laboratory.  (+info)

Reliability of immunohistochemical demonstration of oestrogen receptors in routine practice: interlaboratory variance in the sensitivity of detection and evaluation of scoring systems. (44/1696)

AIMS: To investigate interlaboratory variance in the immunohistochemical (IHC) detection of oestrogen receptors so as to determine the rate of false negatives, which could adversely influence the decision to give adjuvant tamoxifen treatment. METHODS: To ensure that similar results are obtained by different institutions, 200 laboratories from 26 countries have joined the UK national external quality assessment scheme for immunocytochemistry (NEQAS-ICC). Histological sections from breast cancers having low, medium, and high levels of oestrogen receptor expression were sent to each of the laboratories for immunohistochemical staining. The results obtained were evaluated for the sensitivity of detection, first by estimating threshold values of 1% and 10% of stained tumour cells, and second by the Quick score method, by a panel of four assessors judging individual sections independently on a single blind basis. The results were also evaluated using participants' own threshold values. RESULTS: Over 80% of laboratories were able to demonstrate oestrogen receptor positivity on the medium and high expressing tumours, but only 37% of laboratories scored adequately on the low expressing tumour. Approximately one third of laboratories failed to register any positive staining in this tumour, while one third showed only minimal positivity. CONCLUSIONS: There is considerable interlaboratory variability, especially in relation to the detection of breast cancers with low oestrogen receptor positivity, with a false negative rate of between 30% and 60%. This variability appears to be caused by minor differences in methodology that may be rectified by fine adjustment of overall technique.  (+info)

Volumetry of hippocampus and amygdala with high-resolution MRI and three-dimensional analysis software: minimizing the discrepancies between laboratories. (45/1696)

Within the medial temporal lobe, both the hippocampus and amygdala are frequently targeted by researchers and clinicians for volumetric analysis based on magnetic resonance imaging (MRI). However, different data acquisition techniques, analysis software and anatomical boundaries have in the past made it difficult to compare results of MRI studies from different laboratories. In order to reduce these differences, a segmentation protocol was established with 40 healthy normal control subjects recently scanned in our laboratory. Data acquisition was performed with a three-dimensional gradient echo technique, and scans were corrected for non-uniformity and registered into standard stereotaxic space prior to segmentation. Volumetric analysis was performed manually using three-dimensional software that allows simultaneous analysis of sagittal, coronal and horizontal images. Intra- and inter-rater coefficients yielded correlation coefficients comparable with other protocols. The hippocampal volume was larger in the right hemisphere (3324 versus 3208 mm(3)), while no interhemispheric differences for the amygdala (1154 versus 1160 mm(3)) could be observed. Most importantly, results from recent segmentation protocols for hippocampus and amygdala seem to approach each other with regard to mean volumes and interhemispheric differences. This indicates that the advances in scanning technique, volume preparation and segmentation protocols allow a more precise definition of medial temporal lobe structures with MRI, and that results for mean volumes for hippocampus and amygdala from different laboratories will eventually become comparable.  (+info)

Reproducibility studies and interlaboratory concordance for androgen assays in female plasma. (46/1696)

We conducted studies to determine the magnitude and sources of variability in androgen assay results and to identify laboratories capable of performing such assays for large epidemiological studies. We studied androstanediol (ADIOL), androstanediol glucuronide (ADIOL G), androstenedione (ADION), androsterone glucuronide (ANDRO G), androsterone sulfate (ANDRO S), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA S), dihydrotestosterone (DHT), and testosterone (TESTO). A single sample of plasma was obtained from five postmenopausal women, five premenopausal women in the midfollicular phase of the menstrual cycle, and five women in the midluteal phase, divided into aliquots, and stored at -70 degrees. Four sets of two coded aliquots from each woman were then sent to participating labs for analysis at monthly intervals over 4 months. Using the logarithm of assay measurements, we estimated the components of variance and three measures of reproducibility. The usual coefficient of variation is a function of the components that are under the control of the laboratory. The intraclass correlation between measurements for a given individual is the proportion of the total variability that is associated with individuals. The minimum detectable relative difference is important to evaluate study feasibility. Results suggest that a single sample of ADIOL G, DHEA, DHEA S, and ANDRO G (with two lab replicates per sample) can be used to discriminate reliably among women in a given menstrual phase or menopausal status. The results for DHT, TESTO, ADION, and ANDRO S are more problematic and suggest that the present measurement techniques should be used with care, especially with midluteal phase women. The results for ADIOL suggest that this assay is not yet ready for use in epidemiological studies.  (+info)

Development of standards for laboratory automation. (47/1696)

In clinical laboratories, the installation of total laboratory automation systems and/or modular systems has grown dramatically in the 1990s, particularly in the US, Japan, and Europe. As the number of installations and level of interest grew, several individuals and corporations active in the automation field recognized that the development of prospective standards might enable customers of such systems or equipment to purchase analyzers, automation systems or devices, and software from different vendors and retain interconnectivity of such equipment. These individuals also believed that the total market for automation systems and equipment would be significantly greater with standards than without standards, especially if customers were not forced to purchase everything from one vendor, and that there might be competitive pricing and new technology fostered via the standards. This early interest in standards development led to the initiation of a program by NCCLS in 1996 to develop prospective standards for laboratory automation. Part of the NCCLS effort has involved interaction and cooperation with other standards organizations in the US and other countries. This report describes the current status of the development of prospective standards for laboratory automation by NCCLS and the relationship of those standards to those of other standards organizations.  (+info)

The role of total laboratory automation in a consolidated laboratory network. (48/1696)

BACKGROUND: In an effort to reduce overall laboratory costs and improve overall laboratory efficiencies at all of its network hospitals, the North Shore-Long Island Health System recently established a Consolidated Laboratory Network with a Core Laboratory at its center. METHODS: We established and implemented a centralized Core Laboratory designed around the Roche/Hitachi CLAS Total Laboratory Automation system to perform the general and esoteric laboratory testing throughout the system in a timely and cost-effective fashion. All remaining STAT testing will be performed within the Rapid Response Laboratories (RRLs) at each of the system's hospitals. RESULTS: Results for this laboratory consolidation and implementation effort demonstrated a decrease in labor costs and improved turnaround time (TAT) at the core laboratory. Anticipated system savings are approximately $2.7 million. TATs averaged 1.3 h within the Core Laboratory and less than 30 min in the RRLs. CONCLUSIONS: When properly implemented, automation systems can reduce overall laboratory expenses, enhance patient services, and address the overall concerns facing the laboratory today: job satisfaction, decreased length of stay, and safety. The financial savings realized are primarily a result of labor reductions.  (+info)