Handling of large brain specimens: the use of microwaves. A review.
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Brain↗
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Results for “SPECIMEN HANDLING”
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[Quality assurance of pathology laboratories: analysis of histopathological diagnosis of endoscopical biopsies from lower alimentary tract based on specimen types].
As a part of the internal quality assurance in the pathology laboratories, we focused on the diagnosis of biopsies from the lower alimentary tract, and investigated the number of independent lesions contributing the specimens, biopsy pieces, and paraffin blocks prepared in each pathological examination, from the standpoint of the types of biopsy procedures employed. In addition, we compared those of pre- and post-operative diagnoses, and examined the adequacy in the cases with repeated biopsies. Regarding the procedures, polypectomy and EMR (endoscopical mucosal resection) accounted for more than 60% of all the specimens handled during the study period. Most of the specimens taken by polypectomy or EMR were derived from neoplastic conditions, and roughly 40% of them were from malignancies including borderline lesions in a narrow sense. The examination of the surgically resected specimens confirmed a hundred percent accuracy ratio of the diagnosis on the biopsy specimens. Three cases (7.1%) out of 42 malignancies resected needed repeated biopsies in preoperative confirmation of malignancy, while the remainder (92.9%) had been diagnosed at the initial biopsy. The result disclosed that biopsies possessing both diagnostic and therapeutic value (polypectomy and EMR) are apparently increased in the field of lower alimentary tract, and the difficulty and efforts required for diagnosis are quite different and depend on the biopsy procedures employed.
Biopsy↗
Preanalytical considerations in drug assays in clinical pharmacokinetic studies.
Many hospital pharmacy laboratories undertake drug analysis in biological fluids for the production of pharmacokinetic data. The success of such an undertaking very much depends on the selection of a suitable analytical method and a proper approach to sample collection and handling. This paper surveys the main types of biological specimens taken from the patients for pharmacokinetic drug analysis and discusses factors that affect them during or subsequent to their removal. Guidelines are provided in specimen handling and dealing with many problems which could arise prior to actual analysis. By its very nature this paper brings in many disciplines, the full details of which are well beyond its scope, however, some discussion on pharmacokinetic and bioavailability methods in relation to sampling procedures is included to put the matter into a proper perspective.
Body Fluids↗
Clinical immunology in practice, new opportunities.
While research provides new opportunities for diagnosing and treating patients with allergic and immunological disorders, there are significant challenges to putting these advances into use in clinical practice. Each new test may require clinicians in private practice to battle with a health insurer's designated clinical laboratory in an effort to get this new test and other accurate immunological laboratory studies. A new test may or may not be covered by some health care plans and may or may not be available from their designated laboratories. Many of these laboratories send time-sensitive samples across the country with risk of time delays and poor specimen handling leading to inaccurate results and/or the need to send repeat specimens. The growing role of managed care in every medical decision has led to frustrations for the patient and physician. This frequently requires a consult at a tertiary care center, where laboratory studies may be more easily accessible with fewer restrictions. Where are the new opportunities? Some are found in the enhanced ability to make intelligent decisions in the diagnosis and treatment of immunological diseases. There is now a greater selection and availability of intravenous gamma-globulin (IVIG), that can be matched to individual patient needs. The appropriate selection of these products will decrease adverse reactions and increase safety. There was a major advance in the treatment of moderate and severe asthma with the addition of omalizumab therapy. It provides allergists and immunologists with their first monoclonal humanized anti-IgE antibody.
Antibodies, Anti-Idiotypic↗
Specimen collection and handling.
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Humans↗
The influence of simulated clinical handling on the flexural and compressive strength of posterior composite restorative materials.
OBJECTIVES: The aim of this study was to investigate the influence of clinical handling on the flexural and compressive strengths of two commercially available posterior composites. METHODS: Since the manufacturing of test specimens in a truly clinical situation presents many problems, an in vitro model was developed, consisting of a phantom-head set-up in a clinical operatory. Two composite materials, recommended for use in posterior teeth, were used: P50 APC (3M Dental Products) and Herculite XRV (Kerr, Dental Manufacturing). Beam specimens for 3-point bending tests of both materials and cylindrical specimens for compression test of P50 were made both under ideal laboratory circumstances and under simulated clinical circumstances. RESULTS: The difference in mean flexural strength between laboratory prepared and the quasi-clinically prepared specimens was highly significant for both the specimens handled in a clinical manner was 15% of the flexural strength of the P50 specimens made under laboratory conditions, and the difference for Herculite XRV was 29%. No difference in compressive strength could be shown between the laboratory-fabricated and the quasi-clinically made specimens of P50. SIGNIFICANCE: The relative flexural strength of composite materials in a clinical situation may differ significantly from that predicted from mechanical properties measured in vitro.
Bicuspid↗
Evaluation of the Du Pont Axial Separation system.
We evaluated the Du Pont Axial Separation Technology (AST) system, which permanently separates a blood specimen into serum or plasma and cells in 1 min. Blood was collected in axial processing containers by standard venipuncture techniques and processed in an Axial Separation Module. Paired patient samples (n = 48 serum pairs, n = 50 plasma pairs) revealed no clinically significant differences in results for common chemistry analytes from samples collected in Becton Dickinson Vacutainer Tubes and centrifuged conventionally vs those from samples collected and processed in the AST system, except for a bias in serum (but not plasma) lactate dehydrogenase activity. This bias was dependent on the extent of stretching of the clot during processing and could be minimized by clotting the blood sample horizontally (axially). We believe the rapid separation of blood by the AST system has the potential to substantially reduce preanalytical specimen handling time.
Blood Chemical Analysis↗
A kinetic spectrophotometric assay for rapid determination of acetoacetate in blood.
We describe an automated kinetic assay for acetoacetate in blood. Acetoacetate is enzymatically reduced to D-beta-hydroxybutyrate and the reaction is monitored for 60 s with a reaction-rate analyzer. This technique allows low concentrations of acetoacetate to be measured with good precision and overcomes many of the problems associated with other automated techniques. Our studies on the stability of acetoacetate emphasize the need for care in handling specimens. The use of a reaction-rate analyzer, an item of equipment common to most laboratories, allows for rapid handling of samples in small or large batches, depending on the needs of the laboratory.
Acetoacetates↗
[Influence of specimen processing method on Mycobacterium tuberculosis detection by PCR-reversed dot hybridization].
OBJECTIVE: To evaluate specimen processing with sodium dodecyl (lauryl) sulfate (SDS) on the detection of Mycobacterium tuberculosis by PCR-reversed dot hybridization. METHODS: Totally 266 specimens were collected from sputum, pleural fluid, ascites, urine or blood of patients with active tuberculosis and were treated with SDS or routine method. All specimens handled were tested for detecting M. tuberculosis by PCR-reversed dot hybridization. RESULTS: The detection rate of M. tuberculosis from specimens prepared by SDS method was 65.0% (173/266) as compared with 51.5% (136/168) by routine method. Results from two methods were considered statistically significant (chi(2) = 35.03, P < 0.001). CONCLUSION: The SDS processing method may be used to detect M. tuberculosis from clinical specimens by PCR and enhances the detection rate of M. tuberculosis.
Detergents↗
Diagnostic mycobacteriology laboratory practices.
The resurgence of tuberculosis has forced clinical laboratories to improve the methods used for detection of M. tuberculosis. Current recommendations for diagnostic laboratory performance [7] include (1) daily processing of specimens (i.e., handling these specimens in the same way that all other specimens sent to the laboratory are handled); (2) inoculation of liquid media (e.g., BACTEC) for the primary culture; (3) use of nucleic acid probes or the NAP test for identifying isolates as M. tuberculosis as soon as possible; (4) determining drug susceptibility with use of liquid media; and (5) reporting results of each step to physicians in a timely manner. The immediate goals are to report identification of M. tuberculosis within 10-14 days of receipt of the specimen and to report drug susceptibilities within 15-30 days. This can be done if current technologies are fully utilized. The amplification-based systems for the identification of M. tuberculosis and the luciferase-based systems for rapid determination of drug susceptibilities should help further shorten turn-around times. The results to date demonstrate that these systems are feasible, although they must be reduced to formats that can be used routinely in clinical laboratories. The gene-amplification systems may be the most promising, and they are nearing commercial availability. If the assays function as well during routine use as they have during clinical trials, a clinical laboratory may soon be able to report confirmed M. tuberculosis infection to the physician within hours of receiving a specimen, instead of within the typical period of 2-4 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)
Bacteriological Techniques↗
Home collection kits for HIV testing: evaluation of three strategies for dealing with insufficient dried blood specimens.
Home collection kits allow individuals to obtain a blood specimen at home and send it to a laboratory for HIV testing. In preliminary studies, 15% of kit users submitted specimens considered to be insufficient for analysis. The current Public Health Service policy requires the laboratory to reject all such specimens entirely and request a second specimen, even though some specimens are sufficient to perform an enzyme immunoassay (EIA) but not a Western blot (WB) test. Using decision analysis, we evaluated three strategies to handle specimens sufficient to perform an EIA but insufficient to perform a WB analysis: current recommendation, or baseline, for which no test is preformed and "quantity not sufficient" is reported; alternative 1 , for which an EIA is done and reported as "negative" or "quantity not sufficient" (if initially reactive); and alternative 2, for which an EIA is done and reported as "negative" or "a reactive screening test" (if initially reactive). Baseline strategy requires all consumers with an initial specimen sufficient for EIA only to submit a second specimen, but either alternative requires fewer than 3% to submit a second specimen. Although 80% of consumers with an initial specimen sufficient for EIA learn their test results only with the baseline strategy, more than 99% learn their test results with either alternative. With the scenario of high (2%) HIV prevalence, 91% of consumers who would be told "reactive screening test" are truly infected. At a low (0.1%) HIV prevalence, 33% of consumers who would be told "reactive screening test" are truly infected. When a specimen is sufficient for EIA only, it is preferable to perform the EIA instead of rejecting the specimen, because many persons can get results from the initial specimen and because many fewer are required to submit a second specimen. Current policy should be reexamined in light of these findings.
Blood Specimen Collection↗
Cytomegalovirus quantitation by real-time PCR is unaffected by delayed separation of plasma from whole blood.
A previous study suggested that delayed sample preparation can cause a false-positive plasma cytomegalovirus (CMV) PCR. We evaluated 78 samples submitted for CMV testing, and we report that a 24-h delay in plasma separation did not affect viral quantitation by real-time PCR. Laboratories should evaluate specimen handling requirements for their own PCR technology.
Blood Specimen Collection↗
Vestibular sensory epithelium in Meniere's disease.
Utricle and horizontal semicircular canal ampulla removed during labyrinthectomy from 11 patients with advanced Meniere's disease were studied under light and electron microscope. In light microscopy the epithelium of both sensory areas appeared fairly normal. Many sensory cells revealed fluid-filled crescents at the nucleus and many cells were extensively vacuolated. Ultrastructurally, a part of the observations were apparently artifacts due to specimen handling; some were normal, age-related findings. Some changes were considered secondary to dilation of the endolymphatic space. True signs of degeneration, seldom seen in these specimens were intraepithelial cysts, necrotic cells, and dark homogeneous masses in the sensory epithelium and dilated nerve fibers in the subepithelial tissue. No general degeneration of the utricular macula or ampullar crista seems to occur in Meniere's disease.
Adult↗
A comparison of IgG anti-rubella activity in frozen serum stored in primary gel separation tubes or secondary tubes.
AIMS: To determine the suitability of primary gel separation tubes for the storage of frozen sera intended for serological testing. METHODS: Blood samples from 102 patients were collected into gel separation tubes. The sera from these samples were split between the primary gel separation tubes and conventional plastic storage tubes and frozen. A year later, the tubes were thawed and anti-rubella IgG concentrations were compared for the serum pairs using the Wilcoxon signed rank test. RESULTS: No significant difference was detected between the two storage methods. CONCLUSIONS: Frozen storage of serum samples in primary gel separation tubes is a practical alternative to storing separated sera in secondary containers. Adopting this practice has advantages for laboratories in reducing specimen handling and reducing errors in labelling stored samples.
Adult↗
Quality control by blind sample analysis.
Quality control efforts may be biased consciously or unconsciously. External programs are handicapped by the time lapse before poor performance is disclosed. Bias induced into internal and external quality control efforts by special handling may be eliminated through submission of blind samples originating from wards, clinics, or phlebotomy areas. Evaluation of laboratory performance is obtained under conditions similar to those experienced by the patients' specimens. Calibration performance by operators, which varies considerably, can be monitored. Laboratory clerical activity can be scrutinized and errors quantitated and corrected. Perhaps most important, the sum of the effects of specimen handling and analytic variability can be determined.
Alkaline Phosphatase↗
Audit in histopathology: description of an internal quality assessment scheme with analysis of preliminary results.
In the first six months of a formal Internal Quality Assessment Scheme operating in the Department of Histopathology, Broadgreen Hospital, Liverpool, 1005 items of data were gathered, relating to 80 cases. The scheme entails a random 2% sample of biopsy specimens being selected, each case being analysed using a structured proforma, and a numerical scoring system being allocated to all aspects of specimen handling. Technical and secretarial performance was good while the quality of clinical information provided by the requesting clinician was poor. There was a wide variation in reporting times, which related partly to the complexity of the specimen, and partly to the degree of supervision required by the reporting pathologist. Month by month analysis of reporting times showed a significant increase in reporting times associated with rotation of junior staff, but not with periods of annual leave. Pathologist performance scores were good, but close examination of components of the overall score for an individual pathologist indicated occasional areas of weakness (such as the adequacy of the macroscopic report). It is concluded that this scheme is worthwhile and its practice will be continued indefinitely. The comprehensive nature of the analysis allows for the formal identification of areas of work which need improvement, and the allocation of a formal numerical score allows improvement in these areas to be monitored. The monthly meetings provide a means whereby performance scores are fed back to the participating pathologists, and they are also of general educational value regarding histological reporting practice. It is intended that the scheme be extended to include the assessment of special stains, frozen sections, and adequacy of the report delivery service. The system is easily adaptable for use within other histopathology departments.
England↗
A review of rapid microwave fixation technology: its expanding niche in morphologic studies.
Microwave (MW) fixation methods are important because excellent preservation of both cell structure and antigenicity can be attained several orders of magnitude faster than by routine chemical fixation methods. However, because of the limitations of commercial MW ovens, fixation results are often irreproducible. We present a standardization protocol for MW fixation in household MW ovens that emphasizes magnetron warm-up; the use of a water load during sample irradiation, of an agar/saline/Giemsa model to evaluate uniformity of irradiation within the MW cavity, and of specimen containers with one dimension less than 1.5 cm; and fast specimen handling to prevent conductive heating artifacts after irradiation. We describe a prototypic MW device that improves the precision of sample irradiation and fixes blocks of tissue and cells in suspension in milliseconds. The solutions used to immerse the specimen during irradiation influence the specimen morphology. Aldehyde- or osmium-containing solutions used simultaneously with MW irradiation resulted in the best morphologic preservation of specimens up to 1 cm3. Using MW fixation methods and a postembedding, ultrastructural immunogold-labeling approach, we have localized granule chymase and histamine in rat mast cells and amylase in rat parotid acinar cells.
Animals↗
Is antiglycolysis required for routine glucose analysis?
We obtained -68 pairs of simultaneously drawn serum and fluoride-oxalate plasma samples from patients and analyzed them by a continuous-flow (AutoAnalyzer II) glucose oxidase method. Glucose concentrations ranged from 370 to 3530 mg/L. Glucose concentrations for samples obtained in the fluoride-oxalate preservative averaged 42 +/- 35 mg/L (mean +/- SD) higher than serum. The magnitude of this difference was independent of glucose concentration. Linear-regression analysis of 270 pairs for which the time from collection to separation was recorded indicated that the difference between serum and plasma increased by 0.32 mg/L per minute of delay over a time span of 15 to 295 min. These differences are smaller than those described in standard textbooks. We conclude that, with the specimen-handling process used in our hospital, serum glucose determinations are clinically acceptable.
Blood Chemical Analysis↗