PubMed Health⌕ Search

Biomedical subjects

R N Carey

Publications and source records attributed to R N Carey.

17 recordsLinked to original sources
PubMed1991

Multirule quality control procedures.

Multirule quality control procedures employ combinations of individual quality control rules to increase the probability of error detection without increasing the probability of false rejections to unacceptable levels. Performance characteristics of several example multirule procedures are described, and general recommendations are made for their selection and use. Multistage quality control procedures tailor the control rules employed to the frequency of errors expected during a given phase of analyzer operation. During analyzer startup, sensitive rules are employed; after acceptable analyzer performance is demonstrated, less sensitive rules are used for routine monitoring. As they tend to deteriorate quality control rule performance, between-run variations should be minimized.

Chemistry, Clinical↗
PubMed1979

A comparison of hard and soft glass blood-drawing tubes.

The authors examined both hard and soft glass evacuated blood-drawing tubes for possible effects on clinical chemistry measurements. Using routine laboratory procedures, no clinically or statistically significant difference could be detected in 34 analytes using 66 different methods. A special high-precision study utilizing an adaption of the NBS round-robin procedures for calcium, magnesium, sodium, and potassium detected no difference between paired sera when drawn or stored for 72 hours, or both, in the two types of glass. The authors conclude that the type of glass used in production of the evacuated blood-drawing tubes does not affect the clinical chemistry results obtained.

Blood Specimen Collection↗
PubMed1978

Albumin activation of urinary amylase as determined with the Du Pont aca.

Protein activation of urinary alpha-amylase (EC 3.2.1.1) activity was observed during an evaluation of the Du Pont aca procedure for the determination of urinary alpha-amylase. This activation effect became constant for urinary albumin concentrations exceeding 1.50 g/liter. It is recommended that urinary alpha-amylase be analyzed with sufficient albumin added to maximize this effect. The aca alpha-amylase procedure is compared to an amyloclastic method for both serum and urine analysis. Expected ranges are presented for the aca method for serum and urinary amylase, amylase clearance, and the amylase clearance/creatinine clearance ratio.

Albuminuria↗
PubMed1978

Evaluation of the co-immobilized hexokinase/glucose-6-phosphate dehydrogenase method for glucose, as adapted to the Technicon SMAC.

We assessed the analytical performance of the co-immobilized hexokinase (EC 2.7.1.1) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49) method for D-glucose analysis on the Technicon SMAC. The enzyme-containing coils were usable for one month, or 12 000 tests. Bilirubin, hemoglobin, lipemia, creatinine, uric acid, citric acid, and ascorbic acid did not interfere. Results with this method were compared to those by the National Glucose Reference Method. The upper limits of the total error estimate (a combination of random and systematic errors) were 76, 74, and 125 mg/liter at concentrations of 500, 1200, and 3000 mg/liter, respectively. The error estimates were less than allowable errors based on medical usefulness; thus the method was judged to perform acceptably with respect to the Reference Method. We also present performance data for the routine SMAC glucose oxidase (EC 1.1.3.4)/Peroxidase (EC 1.11.1.7) 3-methyl-2-benzothianolinone hydrazone-N,N-dimethylaniline method, the direct hexokinase method with the Du Pont aca, and the glucose oxidase oxygen-rate method with the Beckman Glucose Analyzer.

Autoanalysis↗
PubMed1976

Assessment of the serum separator tube as an intermediate storage device within the laboratory.

An integral blood-drawing-serum separator tube, (SST) is evaluated for use as an in-laboratory serum storage device. Sera stored in the SST were compared with paired controls that were specimens from the same subjects stored in closed culture tubes. Eighty-six serum chemistry determinations showed no clinically significant change as a result of 48 hours of storage in the original blood-drawing tubes. Storage of serum in this manner provides the laboratory with specimens for reanalysis or additional analyses while eliminating manipulative steps, including serum removal, tube relabeling, and intertube transfers, and reducing errors due to misidentification and/or contamination.

Blood Chemical Analysis↗
PubMed1976

Assessment of a serum separator device for obtaining serum specimens suitable for clinical analyses.

We have evaluated a serum separator device that is designed to effect better separation and isolation of serum from clotted blood. This device consists of an evacuated blood-drawing tube (Vacutainer) containing 1.5 ml of a semi-solid silicon polymer that forms a barrier between serum and clot during centrifugation. We compared test specimens with conventionally processed (Vacutainer) specimens as controls. Eighty-one chemical, toxicological, and immunological reactions, tests, or methods were studied. For several tests we observed changes that are statistically but not clinically significant. The one clinically significant change in serum chemistry values occurred in the case of lactate dehydrogenase, for which values were increased by 5-8% of the upper limit of normal.

Blood Chemical Analysis↗
PubMed1976

Automated separation and measurement of lactate dehydrogenase isoenzymes.

We describe a totally automated, computer-controlled system for separating and measuring the activity of lactate dehydrogenase (EC 1.1.1.27) isoenzymes. These isoenzymes in tissue extracts were separated on disposable DEAE-cellulose mini-columns. Resolution was complete except that LD-1 was not resolved from LD-2.

Autoanalysis↗
PubMed1976

Performance studies on the Technicon "SMAC" analyzer: Precision and comparison of values with methods in routine laboratory service.

We present performance studies on the Technicon "SMAC" analyzer. Precision was estimated from control data during routine operation and from blind duplicates of sera from patients. Patients' specimens were analyzed with the SMAC and the SMA 12/60 during initial evaluation studies. Comparisons were also made with the Du Pont aca and other methods during routine service. Performance is judged relative to medical usefulness requirements, by using previously developed criteria and recommendations for decision levels and allowable errors.

Alkaline Phosphatase↗
PubMed1976

Field evaluation of the Becton-Dickinson SST.

The Becton-Dickinson VACUTAINER BRAND SERUM SEPARATOR TUBE (SST) was evaluated in a field test in five hospitals. The SST evacuated blood drawing tube contains a semi-solid silicon polymer which migrates to the serum-clot interface during centrifugation causing a barrier to form which separates serum from red cells. Eighteen clinical chemistry determinations were studied. No clinically significant SST induced changes were observed when compared to conventional blood drawing tubes. Statistically significant changes (t-test, p=0.05) were observed for bicarbonate, calcium, chloride, cholesterol, glucose (Beckman Analyzer), and sodium. For each test (glucose, uric acid, etc.) data were analyzed twice; once as a complete set, and once as a subset consisting of abnormal data only. The small, statistically significant LDH bias observed in the earlier (2,3) clinical trials was not present.

Blood Chemical Analysis↗