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We evaluated the Clinistat Analyzer (Miles Inc., Diagnostics Division, Elkhart, IN) for measuring cholesterol, triglycerides, and high-density lipoprotein (HDL) cholesterol at three medical centers. The system, based on multilayer film technology, uses precalibrated, dry film reagent disks. Ten microliters of serum is applied to the dry film reagent disk in the test procedure. For HDL-cholesterol measurement, serum is pretreated by precipitation with phosphotungstic acid and magnesium chloride. Total precision (CVs) of each of the three assays was less than or equal to 5%. The assay ranges were linear and satisfactory for clinical use. Patients' results compared well with established methods. No significant interferences were found with hemolysis, icterus, and lipemia.

In an effort to reduce overall laboratory costs and improve overall laboratory efficiencies at all of its network hospitals, the North Shore-Long Island Health System recently established a Consolidated Laboratory Network with a Core Laboratory at its center.We established and implemented a centralized Core Laboratory designed around the Roche/Hitachi CLAS Total Laboratory Automation system to perform the general and esoteric laboratory testing throughout the system in a timely and cost-effective fashion. All remaining STAT testing will be performed within the Rapid Response Laboratories (RRLs) at each of the system's hospitals.Results for this laboratory consolidation and implementation effort demonstrated a decrease in labor costs and improved turnaround time (TAT) at the core laboratory. Anticipated system savings are approximately $2.7 million. TATs averaged 1.3 h within the Core Laboratory and less than 30 min in the RRLs.When properly implemented, automation systems can reduce overall laboratory expenses, enhance patient services, and address the overall concerns facing the laboratory today: job satisfaction, decreased length of stay, and safety. The financial savings realized are primarily a result of labor reductions.

Lab automation and consolidation can be a daunting, risky, major reengineering project. Done right, it can mean decreased labor costs and space requirements, increased test volume, and more efficient use of personnel. See how this health system got the job done using a carefully defined, seven-step plan.

The computer, the fax, the cell phone, the pager--all the trappings of the information age--cause much stress in the workplace. Mastering these gadgets--knowing how and when to use them and dealing with the barrage of messages generated by them--is essential to maintaining workplace sanity.

We evaluated the Clinistat Analyzer (Miles Inc., Diagnostics Division, Elkhart, IN) for measuring cholesterol, triglycerides, and high-density lipoprotein (HDL) cholesterol at three medical centers. The system, based on multilayer film technology, uses precalibrated, dry film reagent disks. Ten microliters of serum is applied to the dry film reagent disk in the test procedure. For HDL-cholesterol measurement, serum is pretreated by precipitation with phosphotungstic acid and magnesium chloride. Total precision (CVs) of each of the three assays was less than or equal to 5%. The assay ranges were linear and satisfactory for clinical use. Patients' results compared well with established methods. No significant interferences were found with hemolysis, icterus, and lipemia.

Diet can play a key role in the pathogenesis of cancer. Diets high in fat and low in fiber predispose individuals to colon cancer. A high-fat diet is also implicated in breast cancer and prostate cancer. The dietary fat-cancer linkage is supported by epidemiological evidence, animal studies, and prospective trials. The antioxidants vitamin E, ascorbic acid, and beta-carotene have a protective effect and act as antipromoters of carcinogenesis. A diet of less than or equal to 10% of calories from fat and less than or equal to 40 g of fiber daily that includes fruits and vegetables will prevent up to 35% of cancers.

We evaluated a colorimetric assay of potassium in plasma and serum with the Boehringer Mannheim Reflotron reflectance photometric analyzer, which is designed for near-patient testing in hospitals and physicians' offices. This potassium method does not require calibration or instrument maintenance by the operator. Analysis of 30 microL of plasma or serum takes approximately 140 s. Within-day imprecision (CV) was 1.0-1.2%. Total CVs over a 1-month period were 1.0-1.4%. Patients' results from the Reflotron correlated well with those from the IL 643 flame photometer and the Beckman Synchron CX3 ion-selective electrode methods. The accuracy of Reflotron values was also verified with Standard Reference Material 956 from the National Institute of Standards and Technology.

We evaluated the quantification of high-density lipoprotein (HDL) cholesterol in plasma with the Boehringer Mannheim Reflotron reflectance photometric analyzer. The Reflotron is designed for testing in small to medium-size laboratories and physicians' offices. This HDL method does not require a manual precipitation step because the reagent tab contains dextran sulfate (Mr 50,000) and magnesium acetate. It takes 90 s to complete an analysis of 30 microL of plasma. Within-day standard deviations (SDs) were 0.02-0.04 mmol/L (6-16 mg/L). Total SDs over a three-month period were 0.03-0.06 mmol/L (11-23 mg/L). The Reflotron values averaged 0.02 mmol/L (6 mg/L) or 1.3% lower than the Hitachi 737 values; the standard error of the estimate (Sy.x) was 0.07 mmol/L (29 mg/L).

The analytic performance of the Reflotron System for cholesterol testing has been assessed in 17 studies since 1987. The precision of the test (total coefficient of variation) ranged from 0.8% to 9.9% and was between 1% and 5% in 23 of the 27 specimen types tested. The correlation coefficient of the Reflotron with that of a reference methods was over .9 in 15 specimen types tested and over .95 in ten of 15. The type of specimen tested and the training of the test personnel affected both precision and accuracy. It is concluded that the Reflotron analyzer provides reliable and accurate cholesterol measurements.

In this chapter the application of multivariate techniques for the assessment of laboratory tests in cancer patients has been reviewed. We emphasize that the transformation of laboratory test values into just two categories (normal or abnormal) may entail a considerable loss of information. For instance, correlation between two laboratory tests that may be important for differentiating among various clinical categories of patients may disappear when this procedure is used. When only a single set of laboratory results measured in the same specimen is available for a given patient, we must compare these values to those obtained from other patients or healthy subjects to make inferences about the patient on the basis of the laboratory results. Thus, the analysis of the data must be group based. Discriminant analysis, logistic regression analysis, and survival analysis based on Cox's regression model are the techniques most often used in this situation. By contrast, when previous results are available from the same patient we may compare his or her present values to those previously obtained when we want to make inferences about the patient. Our objective is to make a prediction about the time that will elapse until some specified event (death or recurrence of disease) occurs. Two models that have been applied in this situation--the Markov chain and the autoregressive time series model--were reviewed and examples of specific medical applications presented.

We have assessed the analytical and clinical performance of five thyroid-function tests by commercially available radioimmunoassays in which antibodies attached to paramagnetic micro-particles are used (Corning MAGIC assays). We evaluated the methods for measuring thyroxin, triiodothyronine, triiodothyronine uptake, thyrotropin (thyroid-stimulating hormone), and free thyroxin. Precision, patients' results, and clinical correlation of the MAGIC assays were similar to those of the well-established RIAs used as the comparative methods in this study; the MAGIC assays, however, are much faster and easier to perform.

The amidolytic activity of activated kallikrein in plasma can be measured by use of the chromogenic substrate, S-2302 (H-D-Pro-Phe-Arg-pNA). Plasma prekallikrein was activated to kallikrein by exposure to 50 mg/L dextran sulfate in acetone/water (35/65 by vol) at 0 degrees C for 15 min. The acetone slows anti-kallikrein activity and increases the kallikrein activity by 30%. The 37 degrees C reaction mixture contained 0.54 mmol of S-2302 substrate per liter of Tris buffer (pH 7.5 at 37 degrees C). We monitored the change in absorbance at 405 nm for 60 s. The specificity of the substrate for kallikrein was demonstrated by using plasma deficient in prekallikrein (Fletcher trait) diluted with pooled normal human plasma. We recommend collecting blood specimens with sodium citrate as the anticoagulant and with use of a double-syringe technique and all-plastic containers. Plasma kallikrein activity with Chromozym-PK (Bz-Pro-Phe-Arg-pNA) as substrate (y-axis) compared with S-2302 as substrate (x-axis) gave the relation: y = 0.28x + 0.82 (r = 0.94). Day-to-day analytical variation was 2.4% for a pooled plasma with a mean value of 85.9 mukat/L. The mean (and 2 SD) for 50 healthy adults was 86.4 (32.4) mukat/L.

The magnitude and statistical significance of the various biologic and analytic sources of variation of the serum concentration values of seven proteins: albumin, alpha1-antitrypsin, transferrin, orosomucoid, IgG, IgM, and IgA, were evaluated in 12 healthy subjects. Blood specimens were obtained at 0800 h, 1100 h, and 1400 h on one particular day. The analytic error was partitioned into pre-instrumental and instrumental components; the biologic variation was separated into inter-subject variation of mean levels and intra-individual within-day variation. The mean levels of the subjects differed significantly for all seven proteins studied. For the group as a whole there were no consistent diurnal variations of significance. However, for all the proteins, except for IgM, significant individual within-day biologic fluctuations were noted. The within-day biologic variation was smaller than the total analytic variation for transferrin, IgG, orosomucoid, and IgM. When the total analytic variation was separated into pre-instrumental and instrumental components, it was found that the pre-instrumental sources of variation were of a relatively greater magnitude for albumin, IgG, IgA, alpha1-antitrypsin, and IgM.

The precision of routine urine microscopy for counting erythrocytes and leukocytes was evaluated by using a statistical research-planning technique, factorial experimental design. We examined the relative contribution of the technician preparing the urine specimen, the technician reading the urine slide, the time elapsed since receipt of the urine specimen, and the effect of the microscope used. Results obtained by various technicians differed significantly, because of variation in preparation techniques. This study demonstrates that the routine examination of urine for cellular components may be more imprecise than generally believed, and that the technique should be better defined. It is emphasized that the technique of factorial experiments can be used as an important tool for the design of a rational quality-control program.

In the RA-1000, a random-access discrete analyzer, an inert fluorocarbon fluid is used to prevent interaction and carryover. Production-model instruments were evaluated in two laboratories with respect to determination of glucose, creatinine, total protein, inorganic phosphorus, cholesterol, alkaline phosphatase, lactate dehydrogenase, creatine kinase, gamma-glutamyltransferase, and aspartate and alanine aminotransferases. Within-run, among-run, and day-to-day (for 15 days) precision was assessed, and results were correlated with those obtained by the methods routinely in use in our departments. Precision was excellent, correlation acceptable.

We evaluated the relative contributions of various phospholipids to the formation of foam in the amniotic fluid "foam stability test", by use of an artificial system of saline, ethanol, and dipalmitoyl 3-sn-phosphatidylcholine to determine the relationship between dipalmitoyl 3-sn-phosphatidylcholine concentration, ethanol volume fraction, and the threshold of formation of stable foam. At dipalmitoyl 3-sn-phosphatidylcholine concentrations of 20, 40, and 80 mg/liter, the threshold ethanol volume fraction was 0.46, 0.48, and 0.51, respectively. We similarly evaluated the ability of other phospholipids to form stable foam at various concentrations and ethanol volume fractions and found: bovine brain sphingomyelin greater than dipalmitoyl 3-sn-phosphatidylcholine greater than egg sphingomyelin greater than egg lecithin greater than phosphatidylglycerol. The corresponding propensities of different chemical species of phosphatidylcholine to form foam at 40 mg/liter were: dipalmitoyl 3-sn-phosphatidylcholine greater than dioleoyl phosphatidylcholine greater than dimyristoyl phosphatidylcholine greater than dilauroyl phosphatidyl-cho-line.

We characterize two assays of total amniotic fluid surfactant that are based on function: the surface-tension lowering ability of extracts of amniotic fluid lipid (I) and the foam stability index test (II). I is determined on chloroform extracts of amniotic fluid. II is defined as the highest ethanol volume fraction of an amniotic fluid-ethanol mixture that will permit a stable foam to form after 30 s of vigorous shaking. The relationship of I to disaturated phosphatidylcholine concentrations (after osmium tetroxide treatment of the amniotic fluid lipid extract) is in the expected theoretical form of a hyperbolic function. The relation between values for II and disaturated phosphatidylcholine concentrations showed a consistent bias, suggesting that components other than disaturated phosphatidylcholine contribute to stable foam formation. Phosphatidylclycerol concentrations did not appear to account for this bias. The relation between I to II values suggest that both assays measure total surfactant. I, II, and concentration of disaturated phosphatidyl choline are all excellent indicators of fetal pulmonary maturity. From a practical standpoint, the foam stability index test is the most efficient approach to routine assessment of fetal pulmonary status.

We measured individual temporal changes in gamma-glutamyltransferase activity in serum after four consecutive ethanol challenges in each of eight apparently healthy volunteers. Each challenge consisted of ingesting 0.75 g of ethanol per kilogram of body weight on two evenings, followed by five days of abstention during which the activity was assessed at regular intervals. A nine-day abstention period preceded the study, and initial baseline activity was determined. The highest values for the group mean activity were +12%, +11%, +22%, and +18% greater than baseline after the first, second, third, and fourth ethanol challenges, respectively. We noted marked intra-individual and interindividual variation in the enzymic response; peak values ranged from +1% in one subject to +57% in another. The possible causes for these biological variations are discussed.

Using an automated immunoprecipitin method, we assayed human sera for 10 proteins: haptoglobin, orosomucoid, transferrin, alpha1 antitrypsin, alpha2-macroglobulin, IgG, IGa, IgM, complement C3, and complement C4. Blood from 14 healthy subjects (25-40y) was sampled on six separate days. From each venipuncture serum was divided into four eliquots; two were assayed on the day of venipuncture and two were frozen and kept until the end of the study, when all of the frozen samples were analyzed in one batch. With this experimental design, batch-to-batch analytical variation could be estimated, and we avoided confounding it with the biological variation. Data analysis was based on the analysis of variance technique. The average physiological intra-individual coefficient of variation ranged from 2.5% for transferrin to 11.1% for orosomucoid. THe interindividual variation ranged from 9.5% for transferrin to 70.5% for haptoglobin and the ratio between intra-individual variation and interindividual variation ranged from 0.66 for IgM to 0.26 for orosomucoid and transferrin.

We examined whether inter-individual differences in correlation coefficients previously found among subjects truly reflect consistent inter-individual differences or are time-related within an individual. The consitutents studied in this investigation were (a) the enzmes aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase; and (b) the non=protein nitrogen-containing constituents urea, uric acid, and creatinine. Ten healthy women were each subjected to 15 venipunctures over a five-week period (Series I), and, after a two-month interval, were again subjected to 15 venipunctures over a second five-week period (Series II). Before statistical analysis, the data were corrected for the batch-to-batch (day-to-day) arnalytical variation. There was a signiificant (P less than .05) change in the covariance structure (variances or correlation coefficients, or both) between the two series in four of the 10 subjects for the combination of enzymes, and in three other subjects for the combination of nonprotein nitrogen constitutents. Although we found a significant (P lees than .05) average intra-individual variation in the mean values from series to series in the cases of the three enzymes and urea, the magnitude of the inter-series variation in means was relatively small. CV's were: alkaline phosphatase, 3.4%; lactate dehydrogenase, 2.3+; aspartate aminotransferase, 3.3%; urea, 5.0%; uric acid, 1.0%; and creatinine, 1.2%.

We measured activities of six enzymes, three isoenzymes, and12 specific proteins in 81 cord-blood specimens. We found the following mean values (and ranges), all in U/L, for the enzymes: alanine aminotransferase, 15(6-62); total alkaline phosphatase, 117 (32-245); bone alkaline phosphatase, 91(7-208); aspartate aminotransferase, 25 (7-62); creatine kinase, 139 (28-475); -y-glutamyltransferase, 72 (19-407); lactate dehydrogenase, 444 (327874). With six exceptions, all neonates exhibited predominantly bone alkaline phosphatase (>50% of total); most showed >80% bone fraction. Of the 38 plasma specimens assayed, 21 were creatine kinase BB positive, while three of the specimens were positive for the MB isoenzyme. The mean percentage of lactate dehydrogenaseisoenzyme-1 was lowerfor the neonatal population than for our adult reference population; the percentage of isoenzyme-5 was much higher, about three times the mean percentage for adults. Reference intervals for neonates were comparable to adult values for a1-antitrypsin, a2macroglobulin, immunoglobulin lgG, and orosomucoid. Neonatal values were significantly lower than adult values for a1-antichymotrypsin, complement C3, ceruloplasmin, and transferrin. Concentrations of complement C4 (in plasma), haptoglobin, and the immunoglobulins IgA and 1gMwere usually undetectable.

The physician, the vendor of laboratory systems, the dealer, and the clinical laboratorian all play an important role in doctor's office testing. The interaction of these individuals is necessary for the optimal use of doctor's office testing. The laboratorian can work to promote high-quality testing in the office, can assist the physician in deciding what systems to purchase, can develop training programs for those doing tests, and can serve as a back-up facility for additional testing.

To answer the question of whether reference values are useful in clinical decision-making, this article addresses the following major controversies: (1) Are reference subjects representative of the group from which they are selected? (2) To what extent should the process of collecting reference values be standardized and controlled? (3) Can a single distribution of reference values be used in an meaningful way in the process of clinical decision-making.

We have assessed the analytical and clinical performance of five thyroid-function tests by commercially available radioimmunoassays in which antibodies attached to paramagnetic micro-particles are used (Corning MAGIC assays). We evaluated the methods for measuring thyroxin, triiodothyronine, triiodothyronine uptake, thyrotropin (thyroid-stimulating hormone), and free thyroxin. Precision, patients' results, and clinical correlation of the MAGIC assays were similar to those of the well-established RIAs used as the comparative methods in this study; the MAGIC assays, however, are much faster and easier to perform.

An assay has been developed and evaluated that quantifies the surface tension lowering ability of amniotic fluid surfactant. The formation of stable foam following vigorous shaking of amniotic fluid was evaluated by the addition of various amounts of dipalmitoyl lecithin in a solution of ethanol and saline and by fine adjustments of the ethanol volume fraction in the final assay mixture. The foam stability index (FSI) for a particular sample of amniotic fluid was defined as the highest ethanol volume fraction that would permit the formation of stable foam after vigorously shaking a mixture of ethanol and amniotic fluid. The assay is referred to as the FSI test. We report the FSI values in amniotic fluid specimens from 59 patients obtained within 72 hours of delivery. The L/S ratio was measured in 50 of the same 59 specimens. We observed 6 cases of neonatal hyaline membrane disease (HMD) and 2 cases of transient tachypnea of the newborn (TTNB) in this study. No cases of HMD or TTNB occurred with FSI values of greater than 0.47, while 2 cases of HMD were recorded in association with L/S ratios of 2.5 and 2.8, respectively. The potential clinical value of the FSI test is discussed.