Values reported for the three inorganic elements in 'lymphocytes'.
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Calcium↗
Biomedical subjects
R J Elin
Publications and source records attributed to R J Elin.
Calibration of the aca for glucose in cerebrospinal fluid.
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Autoanalysis↗
Considerations for the design of a new laboratory.
The purpose of this article is to relate the process of designing a new Clinical Pathology Department laboratory at the National Institutes of Health and the assessment of the resultant open laboratory design based on the response of the laboratory staff to two questionnaires. The responses indicated acceptance and approval of the large open area, work area design, carpeted floor, and laboratory environment. It is the authors' hope that this information will be of help to other pathology departments who are involved in designing or remodeling a new or existing laboratory.
Community Participation↗
Comparison of automated and manual methods for urinalysis.
The authors compared results for accuracy and precision obtained by a semiautomated prototype International Remote Imaging Systems, Inc. (IRIS) urinalysis workstation (IUW) with those from quantitative manual urinalysis (QMU). Three technologists skilled in urinalysis each performed 172 urinalyses with both the IUW and QMU methods. The results show that the IUW method is likely to yield comparable counts for particulate analytes compared with the QMU, except for casts. The QMU reported significantly (P less than 0.001) more casts than the IUW method. This difference is related to at least a ninefold greater volume of untreated urine examined by the QMU method than the IUW method. The IUW method may provide a more accurate result than the QMU method at very low and high concentrations of particulate analytes. The result from 24 blind duplicate urines also analyzed by each of the three technologists with both methods showed comparable precision for particulate analytes between the two methods except for red blood cells; the QMU method had significantly (P less than 0.001) better precision for this analyte.
Automation↗
Relation of structure to function for the U. S. reference standard endotoxin after exposure to 60Co radiation.
The structure and function of the highly purified U.S. reference standard endotoxin (RSE) were studied after exposure to ionizing radiation from a 60Co source. With increasing doses of radiation, the trilaminar ribbon-like structure of untreated endotoxin exhibited focal swelling, after which only spherical particles were seen by electron microscopy. These morphological changes were paralleled by the respective loss of O-side chain repeating units and pieces of the R-core from the lipopolysaccharide molecules, as demonstrated by electrophoresis. The biologic function of the irradiated endotoxin was assessed with a variety of tests. At higher doses of radiation, a direct relation was observed between the degradation of the molecular and supramolecular structure and the loss of biologic function. At lower doses of radiation, however, there was variability among the functional assays in their rate of change with progressive irradiation of the RSE. The results suggest that the carbohydrate moiety plays an important role both in determining the supramolecular structure and in modulating certain biologic activities of bacterial endotoxins.
Animals↗
A sample preparation for quantitative determination of magnesium in individual lymphocytes by electron probe X-ray microanalysis.
We present a sample preparation method for measuring magnesium in individual whole lymphocytes by electron probe X-ray microanalysis. We use Burkitt's lymphoma cells in culture as the test sample and compare X-ray microanalysis of individual cells with atomic absorption analysis of pooled cell populations. We determine the magnesium peak-to-local continuum X-ray intensity ratio by electron probe X-ray microanalysis and calculate a mean cell magnesium concentration of 39 +/- 19 mmol/kg dry weight from analysis of 100 cells. We determine a mean cell magnesium concentration of 34 +/- 4 mmol/kg dry weight by atomic absorption analysis of pooled cells in three cell cultures. The mean cell magnesium concentrations determined by the two methods are not significantly different. We find a 10% coefficient of variation for both methods of analysis and a 30% coefficient of variation in magnesium concentration among individual cells by electron probe X-ray microanalysis. We wash cells in ammonium nitrate for microanalysis or in buffered saline glucose for atomic absorption analysis. We find cells washed in either solution have the same cell viability (85%), recovery (75%), cell volume (555 microns 3) and cytology. We air dry cells on thin film supports and show by magnesium X-ray mapping that magnesium is within the cells. We conclude that: our microanalysis cell preparation method preserves whole intact lymphocytes; there is no systematic difference in results from the two methods of analysis; electron probe X-ray microanalysis can determine the variation in magnesium concentration among individual cells.
Burkitt Lymphoma↗
Modification of the chemical composition and structure of the U.S. Reference Standard Endotoxin (RSE) by 60Co radiation.
A highly purified bacterial lipopolysaccharide (LPS) preparation was exposed in water to megadoses of ionizing radiation from a 60Co source. As evidenced by electrophoresis, the radiation treatment progressively degraded the lipopolysaccharide molecules by removing first the O-side chain units and then components of the R-core. Chemical analysis of the irradiated (LPS) preparations showed that, in accord with the structural changes, the most profound effects of ionizing radiation occurred in the hydrophilic oligo/polysaccharide moieties (R-core and O-side chain). Progressively higher doses of radiation degraded the simple sugars in decreasing order of galactose, galactosamine, glucosamine, glucose, and heptose. The R-core component 2-keto-3-deoxyoctonate was the most "resistant" sugar derivative to ionizing radiation. Due to its central position in the LPS aggregates in water, even at comparatively high doses of radiation the hydrophobic lipid A moiety of endotoxin was less affected than the sugar components. Of the fatty acids of lipid A, however, either partial conversion of beta-hydroxymyristic acid into myristic acid or selective loss of the former occurred. The observed structural and chemical changes of LPS are consistent with the effect of active oxygen radicals of radiolysis. In addition, the extensive physicochemical changes explain the altered biological reactivity of radiation-treated endotoxins.
Cobalt Radioisotopes↗
The concentration, physical state, and purity of bacterial endotoxin affect its detoxification by ionizing radiation.
Increasing concentrations of a highly purified bacterial lipopolysaccharide preparation, the U.S. Reference Standard Endotoxin, were exposed to increasing doses of ionizing radiation from a 60Co source. At identical radiation doses both the structural change and Limulus amebocyte lysate (LAL) reactivity were progressively smaller with increasing concentrations of the lipopolysaccharide in an aqueous medium. Under the experimental conditions used, there was a linear relationship between the endotoxin concentration and radiation dose for the structural changes. In contrast to endotoxin in aqueous medium, endotoxin irradiated in its dry state showed no decrease in LAL reactivity and rabbit pyrogenicity. Endotoxin exposed to radiation in water in the presence of albumin showed a much smaller decrease in LAL and pyrogenic activities than expected. The results show that the concentration, physical state, and purity of endotoxin influence its structural and functional alteration by ionizing radiation.
Chemical Phenomena↗
Comparison of two methods for determination of magnesium concentration of mononuclear blood cells.
We describe and compare two methods for the determination of magnesium concentration in lymphocytes from cell cultures. The magnesium concentration of lymphocytes was 36 +/- 4 mmol/kg dry weight by atomic absorption spectroscopy analysis and 39 +/- 19 mmol/kg dry weight with electron probe X-ray microanalysis. We found no significant difference between the results for the two methods. The coefficient of variation was 30% for magnesium concentration among individual cells with electron probe X-ray microanalysis.
Burkitt Lymphoma↗
Interference by sulfonylurea drugs with the Jaffé method for creatinine.
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Autoanalysis↗
Analytical approaches for biomedical elemental analysis.
Several different analytical systems are available for biomedical elemental analysis related to human nutrition. The principle, detection limits, analytical artifacts, and applications are presented for the following analytical systems for elemental analysis classified by sample volume: macro volume systems--flame atomic absorption spectroscopy (FAAS) and inductively coupled plasma (ICP); micro volume systems--electrothermal atomization (graphite furnace) atomic absorption spectroscopy (ETA-AAS) and x-ray fluorescence (XRF); and ultramicro volume systems--electron probe x-ray microanalysis (EPX) and laser microprobe mass analysis (LAMMA).
Electron Probe Microanalysis↗
Magnesium variability of lymphocytes from cell culture.
We determined the magnesium content for two different Burkitt's lymphoma cell lines (EW 36 and CA 46) after transfer to new media for 7 consecutive days. Aliquots of the cell culture were washed and the cell pellet was obtained by centrifugation and lysed with distilled water with and without the addition of 0.25% lanthanum oxide. Magnesium was determined by atomic absorption spectrophotometry. The addition of lanthanum permitted the detection of between 8 and 40% more magnesium. The increased magnesium liberated by the addition of lanthanum was calculated as the "bound" magnesium. The results show that the total magnesium is inversely related and the bound magnesium directly related to the age of the cell culture. Thus, there is a decrease of lymphocyte magnesium content and an increase in the percentage of magnesium bound for these two cell lines with increasing age of the cell culture.
Burkitt Lymphoma↗
Four methods for determining total protein compared by using purified protein fractions from human serum.
The proportional bias of four methods frequently used for determining low concentrations of protein was evaluated with human serum protein fractions (Cohn Fractions II, III, IV, and V). Each fraction was assigned a protein concentration value as determined by the biuret method, calibrated with purified human serum albumin monomer. All four methods (Coomassie Brilliant Blue dye-binding, the method of Lowry et al., ultraviolet absorption, and immunonephelometry gave acceptable results for Fraction V (albumin). The ultraviolet absorption and the Lowry methods overestimated the three globulin fractions (II, III, and IV), whereas the other two methods underestimated these fractions. The method of Lowry et al. gave the least proportional bias for the globulin fractions.
Blood Proteins↗
Relationships between magnesium and protein concentrations in serum.
We determined concentrations of magnesium, total protein, albumin, and globulin in more than 74 000 serum specimens from patients and noted a direct linear relationship between the concentration of magnesium in serum and the concentrations of total protein, albumin, and globulin in serum. Albumin and magnesium concentrations are linearly related at high and low albumin concentrations; within the reference interval, however, the magnesium concentration is independent of the albumin concentration. Linear regression analysis suggests that 25% of the total serum magnesium is bound to albumin and 8% to globulins.
Blood Proteins↗
How certain drugs interfere negatively with the Jaffé reaction for creatinine.
Phenacemide and cephalothin may interfere either positively or negatively with the determination of creatinine by the Jaffé reaction, depending on the analytical system. The drug-picrate chromophores maximally absorb within the first minute of reaction (21 s for phenacemide, 45 s for cephalothin), after which the absorbances decrease. Thus, these drugs negatively interfere in analytical systems involving kinetic measurements when the time interval of measurement includes the period of decreasing absorbance.
Autoanalysis↗
Magnesium content of mononuclear blood cells.
The magnesium content of mononuclear blood cells may provide a better assessment of intracellular magnesium or total body magnesium status than does measurement of magnesium in plasma or erythrocytes. We describe a method for determining this, and report results for 20 normal volunteers. The mononuclear cells are separated with a discontinuous Ficoll-Hypaque gradient, washed, centrifuged at 400 X g, and lysed by sonication in 10 mmol/L NaCl. The magnesium in the cell lysate, with 2.93 g of added lanthanum oxide per liter, is determined by atomic absorption spectrometry. The mean mononuclear cell magnesium content in our volunteers was 70.7 (SD 14.1) fg per cell and 9.29 (SD 1.85) mg/g of DNA. The CVs for the determinations of magnesium, DNA, and cell count were 3.0%, 5.0%, and 8.7%, respectively. There was a significant correlation (r = 0.67, p less than 0.001) between results by the two methods of expressing magnesium content of mononuclear cells. However, by either method there were no significant correlations among results for magnesium concentration of mononuclear cells, plasma, or erythrocytes.
Adolescent↗
Molar absorptivity and the blank correction factor.
In photometry, where both the product formed and one or several reactants absorb light at the same wavelength, the absorbance of the "blank" of the sample at the end of the reaction may be less than that measured at the beginning of the reaction, because of consumption of reactant(s). The blank correction factor for the determined result with one light-absorbing reagent is epsilon P / (epsilon P - epsilon R), where epsilon R and epsilon P are the molar absorptivities of the reagent and the product, respectively. We derived a factor for the case when more than one reagent absorbs light at the same wavelength as the measured product. This factor is independent of the concentration of reagent(s) and can correct the determined result or absorbance for the consumption of light-absorbing reagent(s) during the reaction.
Biuret Reaction↗
Three turbidimetric methods for determining total protein compared.
We used human serum protein fractions to evaluate the sensitivity and bias of three turbidimetric methods for determining concentrations of proteins. Each fraction (Cohn Fractions II, III, IV, and V) was assigned a protein concentration value that was determined by the biuret method, which we calibrated with purified monomer of human serum albumin. All three turbidimetric methods (those involving sulfosalicylic acid/sodium sulfate, trichloroacetic acid, and alkaline benzethonium chloride) gave acceptable results for Fraction V with crystallized human serum albumin as the reference material, but there was bias by each of the three methods for the three globulin fractions. The method involving alkaline benzethonium chloride with measurement at 450 nm had the best sensitivity within the range of linearity and the most consistent bias among the three globulin fractions. These results define the dilemma for valid calibration of these methods for total serum protein in cerebrospinal fluid and urine.
Biuret↗