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Biomedical subjects

B E Statland

Publications and source records attributed to B E Statland.

At least 109 records · Page 6Linked to original sources
PubMed1979

Evaluation of two assays of functional surfactant in amniotic fluid: surface-tension lowering ability and the foam stability index test.

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.

Amniotic Fluid↗
PubMed1978

Evaluation of biologic sources of variation of leukocyte counts and other hematologic quantities using very precise automated analyzers.

The authors determined mean day-to-day (daily over five days), mean week-to-week (weekly over five weeks) and mean hour-to-hour (800 h, 1100 h, 1400 h) physiologic intra-individual variation of concentration values of leukocyte cell types, platelet count, and erythrocyte values (hematocrit, hemoglobin) for a group of 20 healthy adult volunteers. Total leukocyte counts and concentration values of leukocyte cell types were determined in duplicate on the Hemalong-DTM Automated Leukocyte Differential Cell Counter to minimize analytic variation. The data sets were analyzed according to an analysis of variance model. The mean physiologic hour-to-hour and week-to-week intra-individual variations in terms of % coefficient of variation included: hemoglobin, 2.5, 2.2; hematocrit, 2.6, 2.7; platelets, 1.6, 6.6; total leukocyte count, 9.4, 15.7; neutrophils, 12.9, 26.0; lymphocytes, 10.3, 13.2; monocytes, 18.6, 19.3; eosinophils, 19.9, 26.9; basophils, 7.4, 15.0; large unstained cells, 13.7, 16.0; "high-peroxidase" cells, 32.7, 25.7. Hour-to-hour variation was partitioned into random diurnal variation, group-consistent diurnal variation, and subject-specific unique individual variation. Subject-specific diurnal variation contributed greatly and statistically significantly to total diurnal variation for many of the leukocyte cell types--especially in the case of eosinophils, where it represented more than half of total diurnal variation.

Adult↗
PubMed1978

Rational basis for foam-stability assays of amniotic fluid surfactant.

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.

Amniotic Fluid↗
PubMed1978

Assessing fetal lung maturation by the foam stability index test.

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.

Amniotic Fluid↗
PubMed1977

Clinical usefulness of alkaline phosphatase isoenzyme determinations.

1. We report on the clinical usefulness of alkaline phosphatase isoenzyme determinations using a combined chemical inhibition method on 731 patient serum specimens exhibiting elevated (greater than 350 U/L) alkaline phosphatase (AP) activity. 2. The relative percentages of the organ-specific alkaline phosphatase activities were computed on the basis of three independent assays: total activity, activity in the presence of 10 mMl-phenylalanine, and activity in the presence of 3.1 M urea. 3. Gamma-glutamyl transferase (GGT) activity assays were also performed on the same specimens. Using an upper reference limit of 30 U/L for GGT and comparing the GGT results with the percent liver AP, we found that the GGT results were 91% sensitive and 60% specific. 4. We conclude that AP isoenzyme determinations are very useful in identifying the organ source(s) responsible for elevated AP values. 5. The reference ranges for several age groups in relation to the adult population and their significance are presented.

Adolescent↗
PubMed1977

Relationship of day-to-day variation of serum iron concentrations to iron-binding capacity in healthy young women.

Biologic intra-individual variations in concentrations of serum iron and serum iron-binding capacity were determined for nine healthy young women in a double experiment. In each of two series approximately one month in duration, venipunctures were performed three times per week. All serum specimens were assayed for iron concentration and iron-binding capacity. The average intra-subject day-to-day biologic variations for the group in terms of coefficient of variation (CV) were 29.3% for serum iron and 8.8% for iron-binding capacity. No significant difference in variances was found for any subject in serum iron concentrations from series I to series II. Only one subject had a significant positive correlation between iron concentrations and iron-binding capacity values. Percentage iron saturation was computed for each iron and iron-binding capacity combination, and the average intra-subject CV was of the same order of magnitude as the CV for serum iron. The clinical significance of an isolated serum iron result in view of the dramatic intra-subject day-to-day variability is discussed.

Adolescent↗
PubMed1977

The effects of ethanol (0.75 g/kg body weight) on the activities of selected enzymes in sera of healthy young adults: 1. Intermediate-term effects.

We report the intermediate-term effects of three consecutive evenings of moderate ethanol ingestion (0.75 g/kg body weight each evening) on activity values for alkaline phosphatase, gamma-glutamyltransferase, creatine kinase, aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase in sera of nine apparently healthy young adults. We define "intermediate-term" effects as those occurring between 10 h and 100 h after completion of the ethanol consumption schedule. The most pronounced changes in enzyme activity for the group of volunteers were: gamma-glutamyltransferase, +25% at 60 h after ethanol ingestion; alanine aminotransferase, +12% at 60 h after ethanol; and aspartate aminotransferase,--12% at 60 h after ethanol. All three enzymes exhibited similar time courses, i.e., mean peak activity changes were observed at 60 h, and all three mean enzyme activity values returned to near baseline by 100 h. The possible explanations for the observed changes and the clinical significance are discussed.

Adult↗
PubMed1977

Effects of ethanol (0.75 g/kg body weight) on the activities of selected enzymes in sera of healthy young adults: 2. Interindividual variations in response of gamma-glutamyltransferase to repeated ethanol challenges.

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.

Adult↗
PubMed1976

Daily variation of lipids and hormones in sera of healthy subjects.

The physiological day-to-day variation of selected hormone and lipid concentration values in sera of healthy subjects was studied. We drew blood specimens from 14 healthy volunteers, aged 22 to 40 years, (8 male and 6 female) at 0800 h on six separate days over a ten day interval. On one occasion all the twelve specimens from each subject (6 days X 2 replicates) were assayed for the hormones: thyroxine and cortisol; and the lipips: cholesterol and triglyceride which were analyzed by enzymatic methods. The assays were performed on one occasion in order to eliminate the batch-to-batch analytical variation which would tend to blur the physiological day-to-day variation. Using an analysis of variance technique, the total variation was separated into the physiological intraindividual day-to-day variation, the biological inter-individual variation, and the within-batch analytical variation. The mean physiological day-to-day variations in terms of percent coefficient of variation were 7.5% for thyroxine, 26.6% for cortisol, 4.8% for cholesterol, , and 25.0% for triglycerides.

Adult↗
PubMed1976

The effect of a short burst of exercise on activity values of enzymes in sera of healthy young men.

We report the effect of exercise on the activity values of five enzymes in sera as studied in four healthy male volunteers. The underlying purpose of this present study was to produce an increase in the activity values in the sera of selected enzymes found in muscle. Then by observing the decay rate of these enzymes, we computed the inter-individual differences in clearance rates serum half-life) of these enzymes. Blood specimens were collected just prior to exercise, 1 h after excerise, and on eight additional times up to 93 h after exercise. All specimens were assayed on one occasion for activity values of creatine kinase, asparate aminotransferase, alanine aminotransferase, alkaline phosphatase, and lactate dehydrogenase. We found increases in the three muscle enzymes with average increases being: creatine kinase, +116%; asparate aminotransferase, +41%; and lactate dehydrogenase, +32%; all of which remained above baseline values for 53 h or longer. In the case of creatine kinase, a monoexponential decay curve depicted the data (from the 19-h specimen to the 67-h specimen). The calculated "apparent serum half-life" for creatine kinase varied from 38 h to 118 h in the subjects tested.

Adult↗
PubMed1976

Variation of serum iron concentration in young healthy men: Within-day and day-to-day changes.

1. Serum iron concentration values were determined on a group of 11 healthy young men on blood specimens which were drawn at various hours of the day: 800 h, 1100 h, and 1400 h; on each of four separate days. 2. using a three-way ANOVA (analysis of variance) model, we determined the diurnal variation both for the group as a whole (main hour effect) and for the individual subjects (subject-hour and subject-day-hour interactions). 3. the total combined within-day variation as expressed in coefficients of variation was 12.9% with the peak value seen at 1400 h. 4. on a separate study, blood specimens were obtained at 1100 h on five separate days during a two week period on the same volunteers. 5. using a two-way ANOVA model (subject and day) the day-to-day coefficient of variation was found to be 26.6% for the group. In both cases (within-day and day-to-day) the biological variation was considerably greater than the analytic variation.

Adult↗
PubMed1976

Biologic and analytic components of variation of concentration values of selected serum proteins.

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.

Adult↗
PubMed1976

Variations of cholesterol and total lipid concentrations in sera of healthy young men. Differentiating analytic error from biologic variability.

Three major sources of variation affecting serum cholesterol and serum total lipid concentration values were studied in a group of healthy men. The first source of variation, analytic error, was separated into pre-instrumental and instrumental components. The pre-instrumental component, which consisted of all uncertainties occurring from the instant of venipuncture to the entrance of the sample into the instrument, was statistically significant for total lipids. The second major source of variation-preparation of the subject-was evaluated for four major stresses: diet, exercise, posture prior to venipuncture, and duration of tourniquet application. Diet affected total lipids, while the specifics of posture and tourniquet application were statistically significant for both serum cholesterol and total lipids. The third source of variation considered was the within-day and the day-to-day changes. Within-day changes were divided into within-hour and hour-to-hour effects. Day-to-day changes occurred over a two-week period. The magnitude and statistical significance of the changes were evaluated using an ANOVA model. The C.V.'s of day-to-day changes for cholesterol and total lipids (biologic) were 5.3% and 10.2%, respectively while the hour-to-hour within-day C.V.'s were 3.8% for cholesterol and 10.4% for serum total lipids. In all cases the biologic variation was in far excess of the analytic variation. The significance of these factors affecting intraindividual variation in healthy subject is discussed.

Adult↗
PubMed1976

Factors contributing to intra-individual variation of serum constituents: Physiological day-to-day variation in concentrations of 10 specific proteins in sera of healthy subjects.

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.

Adult↗