PubMed HealthSearch

Biomedical subjects

F H Wians

Publications and source records attributed to F H Wians.

At least 19 recordsLinked to original sources

Comparison by race of total serum IgG, IgA, and IgM with CD4+ T-cell counts in North American persons infected with the human immunodeficiency virus type 1.

European patients with human immunodeficiency virus type 1 (HIV-1) infection have been reported to have lower titers of anti-p24 antibody than Central African HIV seropositive patients. Recently, black HIV positive patients in the United States were reported to be more likely to have detectable anti-p24 antibodies, less p24 antigenemia, and higher combined serum immunoglobulins than white HIV positive patients. We measured individual total serum immunoglobulins in 853 HIV positive patients (94% male; 58% white and 42% black) on their initial medical evaluation and compared them with CD4+ T-cell counts. Blacks had notably higher IgG levels (p = 0.001) across the entire spectrum of CD4+ T-cell counts. Serum IgM levels were slightly higher in blacks. IgA levels were not significantly different between the races, although the trend (p = 0.006) was toward higher levels in whites. We also measured these three serum immunoglobulins in 60 HIV seronegative, healthy blood donors (30 black and 30 white). In this control group, blacks had statistically higher IgG and IgA levels than whites. A review of the literature prior to the HIV/acquired immune deficiency syndrome epidemic also supports the view that racial differences in IgG levels are not specific for HIV infection. We speculate that racial differences in humoral immunity, independent of geography or strain of HIV, may account for differences in anti-HIV antibody levels and HIV antigenemia.

Acquired Immunodeficiency Syndrome

Interlaboratory standardization of measurements of glycohemoglobins.

The diversity of methods used to measure glycohemoglobins (GHb) makes it difficult to compare patients' results among laboratories. We reported previously the feasibility of providing comparable results from different assays by use of common calibrators. We here compare results from seven different GHb methods calibrated by use of hemolysates assayed by a precise ion-exchange high-performance liquid-chromatographic (HPLC) method for hemoglobin A1c (HbA1c). Thus, regardless of the GHb species measured by the seven methods, results were referenced to the HbA1c content of the calibrators. Without this calibration, GHb values for single samples varied, e.g., from 4.0% to 8.1% and from 10% to 14.2% in the normal and high ranges, respectively. Calibration decreased between-method variability (single sample ranges of, e.g., 4.8% to 5.4% and 9.4% to 10.2% in the normal and high ranges, respectively) and improved interassay precision. We conclude that this approach to calibration of GHb measurements allows direct comparison of results obtained by different methods and improves precision.

Calibration

Plasma protein and apolipoprotein synthesis by human yolk sac carcinoma cells in vitro.

Three human yolk sac carcinoma cell lines were characterized for the expression of several markers. Each of the cell lines expressed alpha-fetoprotein, without detectable levels of chorionic gonadotropin, and the level of alpha-fetoprotein expression increased dramatically when the cultures were held without passage for extended periods. The secretion of a number of plasma proteins was documented by metabolic labeling, immunoprecipitation, and gel analysis. The major plasma proteins detected were alpha-1-antitrypsin, alpha-fetoprotein, transthyretin, beta-2 microglobulin, and plasminogen, with lower levels of transferrin and complement C4 released. Apolipoproteins B, E, and A1 were secreted in high levels as well and were found in the form of lipoprotein particles. Time course experiments on the synthesis of apolipoproteins E and A1 indicated that, as with alpha-fetoprotein, the level of synthesis increased substantially when the cultures were held without passage. The results indicate that these yolk sac carcinoma cells display a protein expression profile similar to that observed for the human yolk sac, and the possibility that the cells may have the potential to differentiate is discussed.

Apolipoproteins

Prospective evaluation of maternal serum human chorionic gonadotropin levels in 3428 pregnancies.

As part of a multicenter prospective study, second-trimester human chorionic gonadotropin and alpha-fetoprotein concentrations were evaluated. Data included maternal age, human chorionic gonadotropin level, alpha-fetoprotein level, weight, race, and pregnancy outcome of 3428 pregnancies at between 15 and 20 weeks' gestation. The results of the study indicate that human chorionic gonadotropin levels decrease as maternal weight increases, that weight-adjusted human chorionic gonadotropin levels for Oriental and black women are higher than for white or Hispanic women, and that twin pregnancies have higher human chorionic gonadotropin levels than singleton pregnancies. Of 255 pregnancies that did not have normal outcomes, 54 (21.2%) had human chorionic gonadotropin levels greater than 2.0 multiples of the median and 26 (10.2%) had alpha-fetoprotein levels greater than 2.5 multiples of the median. Of 11 pregnancies with fetal aneuploidy, 6 (54.5%) had human chorionic gonadotropin levels greater than 2.0 multiples of the median. It is concluded that in human chorionic gonadotropin screening programs for fetal Down syndrome, weight and race adjustments are necessary for accurate risk assessment.

Aneuploidy

Maternal serum alpha-fetoprotein screening: further consideration of low-volume testing.

Unrecognized assay drift that may occur during low-volume (fewer than 500 specimens per week) maternal serum alpha-fetoprotein testing could result in either underestimation or overestimation of the number of pregnant women who are at increased risk of fetal malformations and genetic anomalies. Quality control software programs that incorporate the use of a multirule Shewhart chart are designed to detect assay drift. Careful selection of quality control sera for inclusion in analytic assays and appropriate application of a multirule quality control procedure to values that are obtained on these control materials should detect assay drift, regardless of the volume of patients' specimens in the run.

Costs and Cost Analysis

Interaction of human embryonal carcinoma cells and differentiated derivatives in vitro with simian virus 40, human adenovirus type 7, or PARA.

Polyclonal antibodies were used to assay human embryonal carcinoma (EC), differentiating EC, yolk sac carcinoma, and teratoma cells for expression of viral early antigen (T-Ag) after infection with simian virus 40 (SV40). Cells of four EC lines were induced to differentiate by cultivation at low density or by exposure to retinoic acid or dimethyl sulfoxide. After infection with SV40, T-Ag was expressed by 1%, or less, of the cells (presumed to be differentiated derivatives) in only some EC cultures whereas the antigen was synthesized by a significant percentage of the yolk sac carcinoma, teratoma, and differentiating EC cells. Also, viral late proteins were produced by EC cells infected with human adenovirus type 7 (Ad7), and SV40 T-Ag was expressed by EC cells after infection with PARA, which is an Ad7-SV40 hybrid virus containing the SV40 T-Ag sequence controlled by Ad7 late regulatory sequences. Thus, T-Ag is not synthesized by the parental EC cells infected with SV40, but it is expressed in cultures of infected differentiated derivatives. The EC cells produce T-Ag, however, when expression of the viral protein is controlled by the Ad7 regulatory sequences in PARA particles. These results demonstrate that expression of T-Ag after infection with SV40 is an indicator of EC cell differentiation and also raise the possibility that, as in mouse EC cells infected with the virus, the SV40 regulatory sequences controlling T-Ag synthesis are not active in human EC cells.

Adenoviruses, Human

Magnesium sulfate pharmacokinetics: pregnant Capra hircus model.

A comparison of standard clinical regimens for the administration of magnesium sulfate for treatment of preeclampsia was performed in the pregnant goat model. The regimen of intravenous or intramuscular load and intramuscular maintenance championed by Pritchard was found to yield higher maternal serum levels through the first 4 hours of treatment compared with intravenous load with intravenous maintenance therapy (p less than 0.05); however, neither regimen affected the concentration of magnesium ion in the cerebrospinal fluid. Urinary excretion of magnesium and passage into the amniotic fluid were also evaluated for each route of administration and neither accounted for the disparity in serum concentrations noted during the first 4 hours of magnesium therapy.

Animals

Guidelines for establishing a maternal serum alpha-fetoprotein screening program.

Maternal serum alpha-fetoprotein (MSAFP) screening of all pregnant women between 15 and 20 weeks gestational age is generally recognized as a standard of care in current obstetric practice. There are many factors to consider when deciding to establish MSAFP testing as an in-house procedure versus ship-out testing by a reference laboratory at fee-for-service cost. In this report, we review clinical and analytical aspects of MSAFP testing, along with appropriate guidelines for establishing an on-site MSAFP screening program.

Body Weight

The effect of hypermagnesemia on serum levels of osteocalcin in an animal model.

Using a pregnant goat (Capra hircus) model to study the in vivo effects of hypermagnesemia on serum osteocalcin concentration, magnesium sulfate infusion has been shown to increase circulating levels of osteocalcin. At 2 h after the administration of magnesium sulfate, a 98% increase in Mg2+ concentration over the basal level resulted in: a 38% increase in serum osteocalcin concentration over baseline; a 22% decrease in PTH concentration, and no change in total and ionized calcium concentrations. These in vivo data support previous in vitro results demonstrating that Mg2+ is a potent inhibitor of osteocalcin binding to hydroxyapatite.

Animals

Osteocalcin-hydroxyapatite interaction in the extracellular organic matrix of bone.

Osteocalcin, a major noncollagenous matrix protein of bone, dentin, and cementum, is found in tight association with the calcium phosphate mineral phase of these tissues. This article reviews the structural data for osteocalcin relevant to mineral adsorption. The equilibrium-binding properties for Ca2+ ions and hydroxyapatite are considered, along with the apparent physicochemical effects of osteocalcin on bone mineral dynamics. Several of osteocalcin's possible biological activities (involvement in mineralization, chemoattraction, and leukocyte elastase inhibition) are discussed in relation to the mineral-adsorption characteristics of this protein.

1-Carboxyglutamic Acid

Benzodiazepines identified by capillary gas chromatography-mass spectrometry, with specific ion screening used to detect benzophenone derivatives.

We developed algorithms for confirmation and identification of benzodiazepines and their metabolites, initially detected in urine samples by enzyme-multiplied immunoassay (EMIT). These algorithms are based on the pattern of benzophenone derivatives of benzodiazepines obtained by gas chromatography-mass spectrometry (GC-MS) with use of a modified specific ion selection mode. Benzophenone derivatives were produced by acid hydrolysis of urine samples containing benzodiazepines and (or) their metabolites. We present mass spectra of the newer benzodiazepines--alprazolam, midazolam, and triazolam--and we determined the detection limit (0.2 mg/L) for these drugs as measured with the EMIT d.a.u. benzodiazepine assay and the ETS instrument (both from Syva Co.). We conclude that these algorithms are useful mostly in forensic toxicology in which unequivocal identification of benzodiazepines is the desired goal.

Alprazolam

Thyrotroph function assessed by sensitive measurement of thyrotropin with three immunoradiometric assay kits: analytical evaluation and comparison with the thyroliberin stimulation test.

We evaluated the analytical and clinical performance of three "sensitive" immunoradiometric assay (IRMA) kits (Tandem-R TSH HS, Hybritech, Inc.; EchoClonal TSH, Bio-Rad; Coat-A-Count TSH IRMA, Diagnostic Products Corp.) for measurement of thyrotropin (TSH) and compared their performance against a "regular" IRMA (ARIA-HT, Becton-Dickinson) to determine whether these assays might eliminate the need to perform the thyroliberin (TRF) stimulation test. We concluded that the Tandem and EchoClonal kits may obviate the need to perform TRF stimulation tests in some patients. Using only the basal TSH concentration to predict the TSH response to TRF, we found all three sensitive TSH assays to be useful for detecting abnormal thyrotroph function. Dose-response, linearity, analytical recovery, and specificity were acceptable for all kits, but intra-assay precision at very low TSH concentrations and analytical sensitivity differed considerably among the kits. Using the EchoClonal assay, we established a normal reference interval for TSH of 0.4-4.6 milli-int. units/L.

Adult

Hyperbiliverdinemia in the bronze baby syndrome.

The bronze baby syndrome is an unusual complication of phototherapy for hyperbilirubinemia in the neonate. The pigment or pigments responsible for the discoloration in this syndrome have not yet been identified. Suspected pigments include photodegradation products of bilirubin and copper-porphyrins. We present here the case of a neonate with bronze baby syndrome whose serum had increased spectral absorbance in the region of maximum absorbance for biliverdin. We suggest that biliverdin pigments may also contribute to the "bronze" color associated with this syndrome.

Adult