Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Laboratory Procedures”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 379 records · Page 21Linked to original sources
PubMed2001

Effect of four laboratory decontamination procedures on the quantitative determination of cocaine and metabolites in hair by HPLC-MS.

The testing for drugs of abuse in hair is increasingly used to detect illicit substances. Laboratories have implemented various decontamination, or washing, procedures in order to eliminate concerns regarding potential contamination of the hair with drug from the environment. However, the effect of these decontamination procedures on drug incorporated into the hair shaft via systemic exposure is unknown. This study evaluated the effect of four simple laboratory wash procedures on the quantitative measurement of cocaine and its metabolites in hair from rats administered cocaine by intraperitoneal injection. Washes included (1) methanol only; (2) 0.1 M phosphate buffer, pH 6.0; (3) 0.1 M phosphate buffer, pH 8.0; and (4) isopropanol and phosphate buffer, pH 5.5. Cocaine and its major metabolites, benzoylecgonine, norcocaine, ecgonine methyl ester, and cocaethylene, were analyzed using high-performance liquid chromatography coupled to atmospheric pressure electrospray ionization mass spectrometry. All four washes resulted in significant differences from unwashed hair controls (p < or = 0.05) for some or all of the detectable analytes. Because different wash procedures lead to significant differences in the measured concentrations of analytes in hair known to contain drug, quantitative data must be interpreted cautiously based on the wash procedures employed.

Animals↗
PubMed2006

An adaptive clinical test of temporal resolution.

PURPOSE: It has been recommended that diagnostic and screening test batteries for auditory processing disorder (APD) include a measure of temporal gap detection using broadband noise stimuli. Although psychophysical laboratory procedures exist for the measurement of temporal resolution, none are clinically feasible. This study was designed to obtain preliminary data on a new clinical measure of gap detection, the Adaptive Test of Temporal Resolution (ATTR). METHOD: The ATTR, a currently available clinical test (Random Gap Detection Test), and a standard psychophysical laboratory procedure were used to measure gap detection thresholds (GDTs) from a group of 30 young adults with normal hearing. RESULTS: Mean ATTR GDTs were 2.2 ms, consistent with GDTs measured using the psychophysical laboratory procedure (3.2 ms) and significantly smaller than those measured using the Random Gap Detection Test (7.0 ms). CONCLUSIONS: Because it incorporates standard adaptive psychophysical methodology in a computer application that can be used on any desktop computer but does not depend on specialized hardware for application, the ATTR promises to be a clinically feasible addition to the APD test battery.

Acoustic Stimulation↗
PubMedDate not supplied

Physicians' risk attitudes, laboratory usage, and referral decisions: the case of an academic family practice center.

Individual differences in physicians' laboratory use and referral rates are important aspects of practice variation that have real financial and health consequences. A way to explain these differences is needed. In this empirical study, physicians' risk attitudes (measured on a multidimensional scale) are shown to be good predictors of use rates for certain specific laboratory procedures, but not good predictors of physicians' referral rates. A 15-item survey form that measured risk-taking attitudes in the financial, health, social, and ethical domains was administered to all clinical faculty at an academic family practice center (n = 14). Each physician's utilization rates for the 17 most frequently ordered laboratory procedures were calculated for all patient visits for one calendar year. Overall referral rates were calculated for the same period. Physicians' risk attitudes (12 completed the survey) accounted for over 50% of the variance for several of the laboratory procedures. For example, the rank-order correlation between the complete blood count utilization rate and a Likert-scale item measuring physicians' propensity to take physical risks was 0.91 (p less than 0.001). The details of these findings help to explain an important component of practice variation.

Academic Medical Centers↗
PubMed2004

Salmonella culture: sampling procedures and laboratory techniques.

In some respects, the multitude of options for isolation of Salmonella and the lack of interlaboratory consistency make Salmonella isolation one of the most variable procedures in veterinary laboratories. Even with the vast number of techniques available, it seems that at least one or two new media become available every year that promise to be more sensitive, more specific,and more rapid. With all the potential media and techniques available, the diagnostic laboratory must choose those that efficiently and accurately give the timely results required clinically and epidemiologically. Many veterinary diagnostic laboratories have invested the time and effort to explore these options and usually have developed standard methods to ensure that their laboratory tests have high sensitivity and specificity. Clients have greater assurance in the accuracy of laboratory results if these standards and the process of deriving them are made available to them. Many laboratories participate in external quality assurance programs to demonstrate their ability to culture microorganisms accurately. These quality control programs are designed to ensure that the client receives the correct answers to questions that are vital for the treatment and health care of their horses. This important information is available only if the initial steps of collecting and shipping the samples have been executed appropriately.

Animals↗
PubMed2000

Marginal fit of nickel-chromium copings before and after internal adjustments with duplicated stone dies and disclosing agent.

STATEMENT OF PROBLEM: Despite careful procedures, master stone dies may be damaged during laboratory procedures. The dentist routinely adjusts castings because the marginal fit of casting is not as accurate as on the dies. PURPOSE: This study evaluated the technique of internal adjustment of castings with use of duplicated stone dies and a disclosing agent to improve marginal fit discrepancy. MATERIAL AND METHODS: Thirty-two nickel-chromium copings were fabricated and simulated standard clinical and laboratory procedures with 2 variables: tooth preparation convergence angles of 6 and 18 degrees, with or without internal relief. Master stone dies and their duplicates were selected for coping construction and internal adjustment, respectively. A specimen positioning device was coupled with a Toolmakers microscope to allow reproducibility of measurements. Each coping was evaluated at 8 locations of its marginal perimeter, before and after internal adjustment. RESULTS: Marginal fit discrepancy of copings were significantly reduced with an internal adjustment technique (mean > 52%) for all experimental groups. Tooth preparations with greater convergence and internally relieved castings recorded a better marginal fit. CONCLUSION: The casting internal adjustment technique with use of duplicated stone dies and a disclosing agent substantially reduced marginal fit discrepancy.

Analysis of Variance↗
PubMed2000

[The laboratory in the diagnosis of sexually transmitted diseases].

In light of the wide array of sexually transmitted infections, it is important that accurate, increasingly advanced laboratory procedures be used to identify the specific agents and that the results of these procedures be correctly interpreted. For this reason, guidelines for the laboratory diagnosis of sexually transmitted diseases (STD) must include standardised criteria and protocols. This report presents the results of several Italian studies on the variability of laboratory procedures for diagnosing the most common STD.

Clinical Protocols↗
PubMed2005

[A novel method for patient-oriented assignment of wheelchair cushions based on standardized laboratory testing procedures].

A wheelchair seat cushion represents the interface between the wheelchair and the wheelchair driver and has to manage the force transmission and the stabilization between both of them. An additional very important requirement is the prevention of pressure ulcers by pressure relief and the transfer of humidity and heat away from the patient. The allocation of a cushion to the patient happens normally on the base of a subjective description of the cushion without any transparent decision rules. Consequently the quality of this procedure could be improved by a better description of the cushion, based on standardized laboratory tests and by the development of decision tools helping to identify the main efforts of the user. This article describes a procedure that allows the allocation of wheelchair seat cushions based on the characteristic of cushions from standardized laboratory tests and on the brief description of the user. Additionally the existing principles for wheelchair cushions are listed, described and compared. The possibilities to develop structured decision tools for wheelchair cushions are discussed.

Decision Support Techniques↗
PubMed1981

Laboratory-scale procedure for preparation of horse anti-dog lymphocyte globulin (HADLG).

Procedure of preparation of horse anti-dog lymphocyte globulin on laboratory scale is described. Adsorption of antibodies against dog plasma proteins was performed with the use of immunosorbent prepared by coupling dog plasma proteins to aluminium hydroxide gel. Anti-lymphocyte immunoglobulins G and T were purified using two-step fractionation. Addition of glycine to the purified immunoglobulins prevented the aggregate formation. Purified immunoglobulins were tested in dogs receiving kidney allografts. The short term administration of HADLG significantly prolonged the time of survival of allografted kidney in comparison to the untreated controls.

Animals↗
PubMed1992

Quality assurance and standards in hematopoietic progenitor processing.

Bone marrow transplantation is an increasingly important therapeutic procedure. As more laboratories have become involved in the processing of hematopoietic progenitor cells from marrow or blood, it has been recognized that standards are required for hematopoietic progenitor processing, storage, and handling. Quality assurance is the process of monitoring whether laboratory procedures, equipment, and personnel fulfill their expected functions, and the aim of quality assurance is to ensure compliance with standards. Some standards for hematopoietic progenitor processing have recently been issued by professional organizations. Although these standards are not comprehensive, where applicable they should be met or exceeded. In the absence of published standards, principles of good laboratory practice should guide quality assurance programs. This article presents concepts of quality assurance in hematopoietic progenitor processing, based on standard laboratory practice and published standards.

Blood↗
PubMed1999

The effects of a cumulative alcohol dosing procedure on laboratory aggression in women and men.

OBJECTIVE: This study directly compared the effects of cumulative alcohol dosing procedure on aggression in both women and men. METHOD: Thirteen women and 13 men consumed three beverages 1 hour apart. There were two experimental conditions: (1) a placebo day, when subjects consumed three 240 ml beverages, each containing only 1 ml of alcohol; and (2) an alcohol day, when subjects consumed three 240 ml beverages, each containing 0.35 g/kg of 95% alcohol. Alcohol doses for women were reduced by 8%. Prior to beverage consumption, and periodically after consumption, subjects participated in 25-minute laboratory testing sessions designed to measure aggression. In this paradigm, subjects could earn points by responding on a button, or aggress toward a fictitious opponent who ostensibly subtracted earnings from them. RESULTS: Both women and men showed an increase in aggressive responding after drinking alcohol but not placebo. As a group the greatest increases were observed after consuming the second alcohol drink (BAC = 0.08%). Aggressive responding, however, remained elevated for several hours after alcohol consumption. A post hoc analysis of the data indicated that subjects with high aggression levels under placebo conditions showed the greatest increases in aggression under alcohol conditions. CONCLUSIONS: These results indicate that at least under these conditions, alcohol does increase aggression in both women and men. The aggression-increasing effects of alcohol appear to be long-lasting and specific to individuals with the higher aggressive tendencies while sober.

Adult↗
PubMed2005

Evaluation of analytical methods and workflow performance of the Architect ci8200 integrated serum/plasma analyzer system.

BACKGROUND: The Architect ci8200 is an integrated serum analyzer for photometric, electrochemical and immunological assays. Several assays of each category and the workflow performance of the system were compared with established laboratory procedures in two laboratories. METHODS: Measurements were compared with the ELECSYS 2010 (Roche Diagnostics) for CEA, PSA, FPSA, AFP, folate, vitamin B12, with the CENTAUR (Bayer) for TSH, T4, FT4, FSH and Estradiol, with the LIAISON (DiaSorin) for TSH, FT4 and FT3, with the Behring Nephelometer BN II (Dade-Behring) for ferritin, and with the INTEGRA 800 (Roche Diagnostics), and the AU640 (Olympus) for clinical chemistry assays. Workflow studies were performed to compare times of analysis required for defined analytical workloads. RESULTS: The coefficients of variation (CVs) for within-run imprecision were between 3% and 6% for CEA, PSA, FPSA, AFP and ferritin, and between 3% and 11% for TSH, FT4, FT3, folate and vitamin B12. The CVs for day-to-day imprecision for immunoassays were between 3% and 10%, except for vitamin B12 (CVs 11-13%) and FT4 (CV 10% -13%). For clinical chemistry tests corresponding CVs for within-run imprecision were < 1%, except for HDL, triglyceride, creatinine, ALT, LD and lipase (CVs<2%) and bicarbonate (CV 3%-6%) and magnesium (CV < 3%). The CVs for day-to-day imprecision for clinical chemistry tests were < 1%, except for sodium, CO(2), magnesium, phosphorus, glucose, uric acid, HDL, triglyceride, ALT, AST CK, lipase with CVs < 6% and for CO(2)<11%. Dilutional linearity testing of seven immunoassays and five clinical chemistry analytes resulted in recovery rates of 90-110%. Correlation studies with 15 immunoassays and 25 clinical chemistry tests showed acceptable agreements with established methods. Work flow analyses demonstrated a net gain in time of analysis up to 109 min depending on the size of the sample batch analyzed with the Architect ci8200 as the main analyzer as compared to the currently installed routine laboratory equipment. Median turn-around times were 7 and 30 min for chemistry assays and immunoassays, respectively, when ordered as STAT analyses, and 18 min when chemistry assays were ordered as routine determinations. CONCLUSIONS: Assays on the Architect ci8200 performed well, fulfilling quality control requirements as defined for instance by German quality control guidelines (RiliBAK). Method comparisons showed acceptable agreements with established assays. Workflow studies using the Architect ci8200 documented shorter times of analyses as compared with the conventionally established laboratory routine demonstrating the potential of integrated chemistry/immunoassay analyzers to provide faster and more efficient performance.

Bicarbonates↗
PubMed1996

Occult gastrointestinal bleeding. General overview and approach.

Occult gastrointestinal bleeding is most commonly defined as an acute or chronic loss of blood, the source of which has not been identified after gastroscopy, colonoscopy, and upper gastrointestinal series have been performed. As the title suggests, this article provides a general overview of this disorder. Specific topics discussed include etiology, diagnostic procedures, laboratory studies, radiologic procedures, radionuclide studies, angiography, and endoscopy.

Adult↗
PubMed1978

Intentional poisoning of two siblings by prescription drugs. An unusual form of child abuse.

The two cases described in this report are examples of a bizarre form of a child abuse. Intentional poisoning with prescription drugs was used by the mother to simulate an underlying disease in her two children. Combined with misleading history and interference with laboratory procedures, she confounded physicians for years, and led to unnecessary hospitalizations, treatment and multiple laboratory procedures for these children. This report may alert physicians to earlier recognition of this form of child abuse.

Child↗