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R J Elin

Publications and source records attributed to R J Elin.

At least 127 records · Page 7Linked to original sources
PubMed1985

Hemoglobin interference from in vivo hemolysis.

Laboratory values for specimens from a case of intravascular hemolysis showed that hemoglobin was significantly increased and thus could interfere with the determination of other analytes. We studied this problem by adding increasing amounts of purified hemoglobin (to a maximum concentration of 19.3 mg/L) to aliquots of pooled serum samples. The hemoglobin significantly interfered with the determination of only five analytes: albumin, aspartate aminotransferase, direct bilirubin, and total protein on the SMAC, and creatinine on the Astra. We propose that for cases of proven intravascular hemolysis, values for only the analytes not affected by hemoglobin should be reported. We find lactate dehydrogenase activity useful in assessing the components of in vivo hemolysis; the differences between serum and plasma values for potassium, lactate dehydrogenase, and hemoglobin are related to in vitro hemolysis. Criteria for specimen collection and assessment of type of hemolysis are proposed.

Autoanalysis↗
PubMed1985

Clinical utility of the Limulus amebocyte lysate (LAL) test.

The clinical utility of the limulus amebocyte lysate (LAL) test was assessed with eight different body fluids from 44 different studies. The results show that the LAL test has established clinical utility for the detection of endotoxin in the presence of Gram-negative bacteria with 4 body fluids: cerebrospinal fluid (CSF), urine, cervical and urethral exudates, and ocular exudates. At this time, the data are insufficient to establish clinical utility with 4 body fluids: peripheral blood, portal blood, ascitic fluid, and synovial fluid.

Body Fluids↗
PubMed1985

Comparison of creatinine as determined with the Ames Seralyzer and by three Jaffé-based methods.

We compared results for urinary creatinine, serum creatinine, and creatinine clearance, as determined with the Ames Seralyzer, with results determined with the Beckman ASTRA, the DuPont aca, and Technicon's AutoAnalyzer and SMAC. Results for urinary creatinine from the Seralyzer differed significantly (p less than 0.05) from those obtained with the ASTRA and AutoAnalyzer, but not with the aca. The Seralyzer results for serum creatinine were at least 1.0 mg/L higher (p less than 0.05) than by the other three methods. Results for creatinine clearance from the Seralyzer were 8 to 11 mL/min lower (p less than 0.05) than results by the other three methods. These differences are related to the positive interference by bilirubin in the Seralyzer creatinine method. We also evaluated 23 other compounds for interference with these methods for creatinine.

Autoanalysis↗
PubMed1984

Workload, space, and personnel of microbiology laboratories in teaching hospitals.

The resources needed to operate a microbiology laboratory are known only as rough approximations. In order to gather more information about these resources, a 13-page questionnaire was completed by 50 pathology departments, of which 38 departments provided adequate information about their microbiology sections to permit data analysis. This study reports the results for resource and work load factors and significant regression analyses among these factors for the whole microbiology section and the subsections of aerobic bacteriology, anaerobic bacteriology, mycobacteriology , mycology, parasitology, virology, and antibiotic sensitivity. These data provide a basis for evaluating the current needs of microbiology laboratories and for making projections for the future.

Equipment Design↗
PubMed1984

Comparison of the Du Pont aca and Dow methods for determination of high-density lipoprotein cholesterol.

We compared the Du Pont aca (phosphotungstate-enzymic cholesterol) and the Dow (dextran sulfate/Mg2+-enzymic cholesterol) methods for the determination of high-density lipoprotein cholesterol (HDLC) and total cholesterol in serum from 113 patients. The aca results for both total cholesterol and HDLC were significantly greater (p less than 0.0001) than the Dow results, the aca method overestimating the HDLC concentration (mean recovery 107.2% in serum samples with values assigned by the Centers for Disease Control). The precision of the aca method for HDLC was essentially the same as that of the Dow method. Bilirubin (up to 0.17 g/L), hemoglobin (up to 4 g/L), and slight lipemia (triglycerides up to 5.4 g/L) did not interfere with the aca method.

Autoanalysis↗
PubMed1984

Reaction of picrate with creatinine and cepha antibiotics.

The concentration of creatinine in serum, which is used to estimate glomerular filtration rate, is measured by reaction with alkaline picrate, but this reaction is not specific for creatinine. Although several other cephalosporin antibiotics have been reported not to react with picrate, we reacted picrate with creatinine, cefoxitin, penicillin, and eight different cephalosporins, and found that all compounds reacted with picrate and showed superimposable spectrophotograms with absorption maxima at 485 nm. From these results we conclude that the color-absorbing moiety of the product is the picrate molecule. Further, the structure common to creatinine and the cephalosporins, cefoxitin, or penicillin is the carbonyl group attached to a nitrogen and a carbon atom. We postulate that the carbonyl group with the adjacent carbon and nitrogen atoms is probably the chemical moiety that reacts with picrate to absorb energy at 485 nm.

Cephalosporins↗
PubMed1984

Liquid and lyophilized quality-control materials compared for use in continuous-flow analysis.

Using a Technicon SMAC continuous-flow instrument, we compared a liquid quality-control material ("Decision level 3," Beckman) with two different lyophilized quality-control materials. The variances for 19 analytes in the three materials were significantly greater for Decision than for the Ortho Abnormal and the Omega II lyophilized control sera (p less than 0.00001 for each comparison by the omnibus test). The imprecision for Decision was not due to incomplete mixing or carryover. The viscosity of Decision, however, was more than twice that of the two lyophilized control sera or of pooled human serum.

Autoanalysis↗
PubMed1984

Effect of dialysis on interference by cefoxitin with determination of creatinine.

Interference by cefoxitin with determination of creatinine is less with the Technicon SMAC than with other commercial analytical systems. The SMAC assay involves a single-point kinetic method with dialysis, whereas most other commercial methods are multipoint kinetic without dialysis. The apparent creatinine concentration measured for aqueous solutions of cefoxitin was 73 mmol of creatinine per mole of cefoxitin with the SMAC, 135 mmol/mol with a manual method. Furthermore, we determined for the SMAC that the average fraction of creatinine dialyzed was 0.128 and for cefoxitin, 0.064. Thus, the concentration of and interference by cefoxitin in the reaction mixture for SMAC are reduced by half (i.e., the apparent creatinine concentration for cefoxitin with the manual system multiplied by 0.5 is essentially that noted with the SMAC: 68 vs 73). Thus we conclude that the diminished interference be cefoxitin with determination of creatinine by SMAC is primarily ascribable to the dialysis step.

Autoanalysis↗
PubMed1984

Effect of calibration material lot changes on results for the "SMAC".

The effect of two changes of calibration material (separated by five months) for the SMAC continuous-flow analyzer was followed by means of five quality-control indices: three normal and abnormal control sera, the mean of the central 50th percentile of patients' results, and the mean value for normal individuals. After the first and second changes of calibration materials, eight and six, respectively, of the 20 different tests exhibited statistically significant changes as shown by the indices. The cumulative shift for two of the 20 tests was considered medically significant. Prospective studies on split samples of patients' sera before the change in calibration material only predicted half the significant changes in test results later evidenced by the above-mentioned indices.

Autoanalysis↗
PubMed1983

Predicting space and personnel in academic clinical pathology.

This report compares the results from two surveys of the resources of academic clinical pathology departments. In 1971, the Academy of Clinical Laboratory Physicians and Scientists (ACLPS) obtained data from 25 academic clinical pathology departments on actual workload variables (census, procedures per year, admissions per year, and outpatient visits per year), along with estimates of ideal space and ideal staffing. A study conducted by NIH obtained data from 31 academic clinical pathology departments for 1976 for the same workload variables, along with actual and ideal space and actual staffing. Regression analyses were performed with space, technical personnel, and doctoral personnel as the dependent variables and patients per day, admissions per year, and numbers of procedures per year as the independent variables. For each study, admissions per year and patients per day were statistically significant predictors of both departmental space and technical personnel. The slope of each significant regression from the ACLPS study was greater than the comparable significant slope from the NIH study. These data provide a basis for comparing resources among academic clinical pathology departments, assessing current resources, and projecting future needs.

Academies and Institutes↗
PubMed1983

Comparison of two separation techniques for the determination of blood mononuclear cell magnesium content.

The determination of blood mononuclear cell magnesium content may be a predictor of total body magnesium status. Separation techniques employing Ficoll-Hypaque have been used for this assay; however, Hypaque contains a significant concentration of iodine that may be toxic to the cell membrane and affect the results. We developed a different separation technique using arabinogalactan (Stractan) at concentrations of 13.0 and 17.7%. The blood from 16 normal volunteers was divided and assayed for mononuclear cell magnesium content using both methods. The results (mean +/- standard deviation) with the Ficoll-Hypaque method were 83.6 +/- 30.8 fg/cell, and with the arabinogalactan method they were 78.4 +/- 25.5 fg/cell. A paired sample t test comparing the results between the two methods gave a t value of 1.05 (P greater than .3). The purest population of blood mononuclear cells was obtained with the Ficoll-Hypaque method. Thus, these two separation materials do not have a significant effect on the blood mononuclear cell magnesium content, and the better separation of cells was obtained with Ficoll-Hypaque.

Cell Separation↗
PubMed1983

Workload, space, and personnel of hematology laboratories in teaching hospitals.

The resources needed to operate a hematology laboratory are known only as rough approximations. To gather more information about these resources, a 13-page questionnaire was completed by 50 pathology departments, of which, 34 departments provided adequate information about their hematology sections to permit data analysis. This study reports results for resource and work load factors and significant regression analyses among these factors for the whole hematology section and the subsections of coagulation, special hematology, and bone marrow examination. These data provide a basis for evaluating the current needs of hematology laboratories and for making projections for the future.

Hematology↗
PubMed1983

Physical and biological properties of U.S. standard endotoxin EC after exposure to ionizing radiation.

Techniques that reduce the toxicity of bacterial endotoxins are useful for studying the relationship between structure and biological activity. We used ionizing radiation to detoxify a highly refined endotoxin preparation. U.S. standard endotoxin EC. Dose-dependent changes occurred by exposure to 60Co-radiation in the physical properties and biological activities of the endotoxin. Sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis showed gradual loss of the polysaccharide components (O-side chain and R-core) from the endotoxin molecules. In contrast, although endotoxin revealed a complex absorption pattern in the UV range, radiation treatment failed to modify that pattern. Dose-related destruction of the primary toxic component, lipid A, was suggested by the results of activity tests: both the pyrogenicity and limulus reactivity of the endotoxin were destroyed by increasing doses of radiation. The results indicate that the detoxification is probably due to multiple effects of the ionizing radiation on bacterial lipopolysaccharides, and the action involves (i) the destruction of polysaccharide moieties and possibly (ii) the alteration of lipid A component of the endotoxin molecule.

Animals↗
PubMed1983

Evaluation of four gentamicin and tobramycin assay procedures for clinical laboratories.

Accuracy, precision, and clinical laboratory utility of the TDX (Abbott Laboratories), Auto-ICS (Beckman Instruments, Inc.), COBAS-Bio (Roche Analytical Instruments, Inc.) with reagent kits (Syva), and EMIT (Syva) for gentamicin and tobramycin serum assay were assessed. TDX, COBAS-Bio, and EMIT analytical systems showed a proportional bias of less than 10% for recovery studies and a coefficient of variation less than 5% for within-run precision. The results of the recovery studies with the Auto-ICS showed a proportional bias of 25% with gentamicin and 16% with tobramycin. The within-run precision expressed as the coefficient of variation for the Auto-ICS was 6.7% for gentamicin and 8.6% for tobramycin. In comparisons involving gentamicin- and tobramycin-containing patient samples, the results with the TDX analytical system showed the best agreement with the COBAS-Bio. For the determination of these two antibiotics, the TDX analytical system provided the best overall accuracy and precision.

Gentamicins↗