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Biomedical subjects

W L Trudeau

Publications and source records attributed to W L Trudeau.

At least 37 records · Page 2Linked to original sources
PubMed1993

Elevated serum levels of IL-8 in patients with HIV infection.

Serum levels of IL-8 were determined in HIV-infected individuals and the results were compared with those for HIV- controls. The IL-8 levels were measured by an ELISA with a MoAb and a polyclonal antibody to recombinant IL-8. The means and 95% confidence intervals of IL-8 in sera of 36 HIV-infected individuals and 32 matched controls were 275 and 216-349 pg/ml, and 8 and 4-14 pg/ml, respectively, showing a 34-fold increase in IL-8 in the circulation of HIV-infected individuals. This increase does not appear to be related to the disease state, infection or systemic medical agents. This finding suggests the possible involvement of IL-8 in the pathogenesis of HIV-induced disease.

Adult↗
PubMed1992

Nasal and bronchial provocation challenges with bayberry (Myrica cerifera) pollen extract.

Southern bayberry, distributed throughout the southeastern United States, is the source of the fifth most common windborne tree pollen in Tampa, Fla. Fifteen percent of 400 consecutive subjects evaluated for allergic respiratory symptoms in the Tampa Bay area had positive skin tests to bayberry pollen extract. Bayberry pollen extract was obtained commercially and used to perform 25 nasal and 22 bronchial challenges on 45 subjects. Twelve of 13 (92%) study subjects with allergic rhinitis and positive skin tests to bayberry pollen extract and two of 12 (17%) control subjects with negative skin tests had positive nasal challenges (p = 0.0001). Four of seven (57%) study subjects with extrinsic asthma and positive skin tests to bayberry pollen extract and none of the 15 (0%) control subjects with negative skin tests had positive bronchial challenges (p = 0.001). Sera from 30 subjects who underwent 31 challenges were assayed for bayberry pollen extract-specific IgE by plate radioimmunoassay. Specific IgE antibodies were present in the sera of 8 of 13 (62%) subjects with positive challenges and absent in 15 of 18 (83%) subjects with negative challenges (p = 0.01). Intradermal skin tests with bayberry pollen extract were more predictive of provocation challenge results than plate radioimmunoassay (positive predictive value of 80%, 95% CI 62% to 98%; versus 73%, 95% CI 47% to 99%). Bayberry pollen extract is allergenic, and the Southern bayberry tree fulfills Thommen's criteria defining aeroallergen-producing plants.

Adult↗
PubMed1992

Goodness-of-fit and local identifiability of a receptor-binding radiopharmacokinetic system.

A four-state nonlinear model describing a radiopharmacokinetic system for a hepatic receptor-binding radiopharmaceutical, [99mTc]-galactosyl-neoglycoalbumin (TcNGA), was tested for goodness-of-fit and local identifiability using scanning data from nine healthy subjects and seven patients with severe liver disease. Based on standard deviations of liver and heart imaging data at equilibria as a measure of observational error, the reduced chi-square ranged from 0.5 to 2.6. Values above 1.2 occurred when the subject moved during the 30 min study. Relative standard errors for each parameter were: TcNGA-receptor forward binding rate constant kb, 13-54%; extra-hepatic plasma volume Ve, 0.8-15.0%; hepatic plasma volume Vh, 0.2-6.5%; hepatic plasma flow F, 54----greater than 1000%; and receptor concentration [R]o, 0.3-13%. The highest standard errors occurred when the amount of TcNGA injected exceeded the total amount of receptor. Therefore, when TcNGA functional imaging was performed without excess patient motion and receptor saturation, the kinetic model provided data fits of low systematic error and yielded high precision estimates of receptor concentration and forward binding rate constant. In summary, optimal performance of the kinetic model occurred when the amount of injected TcNGA resulted in the nonlinear operation of the pharmacokinetic system.

Albumins↗
PubMed1991

Source of the aeroallergen of soybean dust: a low molecular mass glycopeptide from the soybean tela.

Airborne soybean allergens in the dust generated during the unloading of soybeans in the harbor caused asthma epidemics in Barcelona, Spain. The major allergen causing the epidemics was a glycopeptide less than 14 kd molecular mass abundant in soybean dust. This allergen occurs in all parts of the soybean plant at all stages of growth, but the telae (hulls) and pods are by far the richest source. Small amounts of a similar cross-reacting allergen are found in some other grain dusts. The botanical function and significance of this soybean plant component is not known nor is the potential for airborne dispersion of this allergen at other grain-handling sites.

Air Pollution↗
PubMed1991

Prevalence of specific IgE to the storage mite, Aleuroglyphus ovatus.

Aleuroglyphus ovatus (Ao) is a storage mite that has a worldwide distribution and has been found in stored bran, wheat, chicken meal, and dried fish products. Ao was isolated from a chicken meal sample, cultured on whole wheat flour at 75% relative humidity, and 1 gm of pure Ao bodies were extracted, 1:20 wt/vol, in 0.2 mol/L of ammonium bicarbonate. Der p I, major allergen of Dermatophagoides, pteronyssinus (Dp), or Der f I major allergen to Dermatophagoides farinae (Df), was not detected in extracts of Ao. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed 25 bands (6 to 110 kd), and thin-layer isoelectric focusing revealed 19 bands (isoelectric point, 3.5 to 9.3). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis immunoblots with six different sera identified nine IgE binding bands (16 to 100 kd). Thin-layer isoelectric focusing immunoblots identified 16 IgE binding bands (isoelectric point, 4.5 to 9.3). An aliquot of the Ao extract was diluted in bicarbonate buffer (pH 9.2) and adsorbed to plastic microtiter plates. RAST to Ao and Dp were performed with sera of 163 atopic individuals (88 with allergic rhinitis and 75 with allergic asthma with or without allergic rhinitis). All individuals had appropriately positive skin tests that correlated with a history of exacerbation secondary to allergen exposure. RAST results to Dp and Ao were analyzed by regression analysis (r = 0.64; p = 0.0001). Fifty-five individuals were RAST positive to Dp alone, 32 to Ao and Dp, and three to Ao alone; 73 individuals were negative to Ao and Dp. RAST inhibition demonstrated moderate cross-reactivity between Ao and Dp.

Adolescent↗
PubMed1991

Caffeine, a naturally occurring acaricide.

Since caffeine is a plant alkaloid that has been described as a naturally occurring insecticide, its acaricidal effect on Dermatophagoides pteronyssinus (Dp) was investigated. Twelve cultures were established by adding 30 Dp to 200 mg of Tetramin fish food and brewer's yeast (8:2 ratio); six cultures were treated with 20 mg of finely ground caffeine. All 12 cultures were incubated at 75% relative humidity, 25 degrees C, and observed during 8 weeks. Live mites were then counted under a stereoscope, cultures were extracted, and supernatants were analyzed for Der p I and Der f I allergen content with a two-site monoclonal RIA. Live mite counts in untreated cultures varied from 146 to 274 (215 +/- 47.1), and in caffeine-treated cultures from 0 to 3 (1 +/- 1.2; p less than or equal to 0.0001). Der p I concentrations in untreated cultures varied from 588 to 9000 ng/gm (3138.3 +/- 2990.8 ng/gm), and in caffeine-treated cultures from 52 to 117 ng/gm (78 +/- 23.8 ng/gm; p less than or equal to 0.01). Der p I was not detected in the food media or caffeine; Der f I was not detected in any of the cultures. Results demonstrate that caffeine inhibits mite growth and allergen production.

Acari↗
PubMed1991

Hepatic uptake of [99mTc]galactosyl-neoglycoalbumin is sensitive to receptor quantity.

[Technetium-99m]galactosyl-neoglycoalbumin (TcNGA) is a synthetic radioligand specific to the receptor, hepatic binding protein (HBP), which resides exclusively at the cell surface of hepatocytes. If the TcNGA time-activity data are to provide valid estimates of receptor biochemistry via pharmacokinetic modeling, the shape of the hepatic uptake curve must change with alterations in receptor concentration or affinity. An index of TcNGA hepatic uptake, T90, was obtained by calculating the time at which the liver time-activity curve reached 90% of its maximum. Receptor quantity was measured by Scatchard binding assay of liver biopsy samples obtained prior to each TcNGA study. The range of T90 was 3.7-16.8 min; HBP quantity ranged from 0.022 to 0.100 mumol. Significant correlation (r) and slope (b) was observed between T90 and HBP quantity (r = 0.82, P = 0.003; tb = 3.98, P = 0.003). We concluded that the hepatic uptake of TcNGA is sensitive to HBP quantity.

Adult↗
PubMed1991

[In vivo measurement of hepatic binding protein in chronic liver disease--validation as a measure of hepatic functional reserve].

[Tc-99m] Galactosyl-neoglycoalbumin (TcNGA) is a synthetic radiolabeled ligand specific to the hepatocyte receptor, hepatic binding protein (HBP), a specific receptor to serum asialoglycoprotein. A TcNGA study was performed on 34 humans: normal volunteers (7) chronic hepatitis (6), hepatic cirrhosis (8), and hepatocellular carcinoma superimposed on cirrhosis (13). Heart and liver time activity curves were obtained following intravenous injection of TcNGA (5 mCi, 1.82 x 10(-9) mol/kg). HBP concentration ([HBP]) was calculated by curve-fitting techniques using the nonlinear three compartment model, which includes biomolecular reaction between HBP and TcNGA. [HBP] values were compared with conventional liver function tests. [HBP] had a good correlation with prothrombin time (n = 34, r = 0.694, p = 0.0001) thrombotest (n = 34, r = 0.692, p = 0.0001), hepaplastin test (n = 26, r = 0.787, p = 0.0001), albumin (n = 34, r = 0.712, p = 0.0001), cholinesterase (n = 34, r = 0.801, p = 0.0001), ICGR15 (n = 33, r = 0.761, p = 0.0001), KICG (n = 30, r = 0.709, p = 0.0001), ICG Rmax (n = 12, r = 0.735, p = 0.0064) and Child-Turcotte classification score (n = 34, r = 0.819, p = 0.0001). We concluded that excellent correlations of [HBP] to conventional liver function tests suggest that in vivo receptor measurement via TcNGA kinetic analysis is a sensitive and promising method in the estimation of hepatic functional reserve in patients with chronic liver disease.

Adult↗
PubMed1991

Measurement of receptor concentration and forward-binding rate constant via radiopharmacokinetic modeling of technetium-99m-galactosyl-neoglycoalbumin.

Technetium-99m-galactosyl-neoglycoalbumin (99mTc-NGA) is a synthetic ligand to the hepatocyte receptor, hepatic binding protein (HBP). A five-state mathematical model containing a bimolecular chemical reaction was utilized for quantitative estimation of the following physiologic and biochemical parameters: extrahepatic plasma volume Ve; hepatic plasma flow F and volume Vh; receptor-ligand forward-binding rate constant kb and reaction volume Vr; and receptor concentration [R]o. Nine normal subjects were studied. Given (a) liver and heart time-activity data, (b) the patient's weight, height, and hematocrit, (c) the fraction of injected dose in a 3-min blood sample, and (d) the amount and galactose density of the NGA dose, a computer program executed a curve-fit to the kinetic model. Systematic error, as measured by reduced chi-square, ranged from 1.43 to 2.56. Based on the nine imaging studies, the mean and relative error of each parameter were: [R]o, 0.813 +/- (0.11) microM; kb, 2.25 +/- (0.15) microM-1 min-1; F, 0.896 +/- (0.20) liter/min; Ve, 1.67 +/- (0.27) liter; and Vh, 0.228 +/- (0.22) liter. Two unique features of 99mTc-NGA radiopharmacokinetic systems permit the simultaneous estimates of receptor quantity, ligand affinity, and hepatic plasma flow. The first is the ability to administer a quantity of ligand capable of occupying a significant fraction of receptor; and the second is a simple model structure that conserves mass.

Adult↗
PubMed1991

Validation of in vivo receptor measurements via in vitro radioassay: technetium-99m-galactosyl-neoglycoalbumin as prototype model.

Hepatic binding protein (HBP) is a hepatocyte-specific receptor for serum asialoglycoproteins. The receptor also recognizes a synthetic glycoprotein that has been developed as a radiopharmaceutical, technetium-99m-galactosyl-neoglycoalbumin (99mTc-NGA). This report describes the correlation between receptor parameters measured in vivo via kinetic modeling of 99mTc-NGA and those measured by in vitro radioassay of biopsied liver tissue. Eleven patients with diffuse hepatic disease underwent percutaneous liver biopsy followed by a 99mTc-NGA functional imaging study. In vivo measurements of HBP quantity Ro and forward binding rate constant kb obtained from the kinetic analysis of 99mTc-NGA liver and blood time-activity data were compared to total receptor quantity and the HBP-99mTc-NGA association constant KA as measured by Scatchard binding assay of the biopsied tissue. The correlation coefficients between in vivo and in vitro measurements were 0.73 (df = 8, p = 0.015) and 0.98 (df = 8, p less than 0.01) for Ro and kb, respectively. The in vivo measurements of HBP biochemistry via kinetic analysis of the radiopharmaceutical time-activity data reflect the average concentration and affinity of the receptor. This study further substantiates the validity of 99mTc-NGA as a quantitative probe for the HBP receptor.

Adult↗
PubMed1990

Serum IgE and human immunodeficiency virus (HIV) infection.

Human immunodeficiency virus infection is characterized by a progressive depletion of helper T-lymphocytes and, like allergic diseases, is associated with altered T cell regulation. Total serum IgE was measured in 67 infected male subjects, 27 uninfected heterosexual male subjects, and 18 uninfected homosexual male subjects. The mean IgE level (132 IU/ml) of infected subjects with a helper T-lymphocyte number less than or equal to 200/mm3 was significantly greater than mean IgE levels of the uninfected heterosexual (38 IU/ml) and homosexual (35 IU/ml) groups. IgE levels were inversely related to both helper T cell and suppressor/cytotoxic T cell numbers but not to IgG or IgA levels. The increase in IgE was not a reflection of an increased prevalence of atopic disease (allergic asthma, allergic rhinitis, or atopic dermatitis) in the infected subjects. The elevation of IgE may be related to a difference among the groups in T cell production of IgE regulatory lymphokines.

Acquired Immunodeficiency Syndrome↗
PubMed1990

In vivo estimates of hepatic binding protein concentration: correlation with classical indicators of hepatic functional reserve.

Hepatic binding protein (HBP) is a hepatic cell surface receptor specific for asialoglycoprotein. In vivo estimates of HBP concentration ([HBP]) were compared to classical indicators for hepatic functional reserve to clarify the validity of [HBP] in estimating the hepatic functional reserve in 30 humans. Estimates of [HBP] were obtained based on kinetic analysis of liver and blood time-activity data resulting from the hepatic clearance of a single injection of technetium-99m galactosyl-neoglycoalbumin, which is a synthetic analog radioligand specific to HBP. Estimates of [HBP] ranged 0.054 to 0.720 microM. Estimates of [HBP] in normal volunteers were 0.668 +/- 0.050 microM, whereas that in liver cirrhosis were 0.188 +/- 0.112 microM. The difference between the mean values of [HBP] estimates was statistically significant (p = 0.0001). Good correlations were observed between [HBP] and prothrombin time (r = 0.625, p = 0.0002), serum albumin level (r = 0.687, p = 0.0001), serum cholinesterase level (r = 0.764, p = 0.0001), indocyanine green plasma disappearance rate (r = 0.602, p = 0.0024), and Child-Turcotte classification score (Pugh's modification) (r = -0.797, p = 0.0001). We concluded that excellent correlations of [HBP] with classical indicators for hepatic functional reserve suggest potential value of [HBP] as a sensitive measure of functioning hepatocyte mass.

Adult↗
PubMed1985

Technetium-99m NGA functional hepatic imaging: preliminary clinical experience.

Technetium-99m galactosyl-neoglycoalbumin ( [Tc]NGA) is a radiolabeled ligand to hepatic binding protein, a receptor which resides at the plasma membrane of hepatocytes. This receptor-binding radiopharmaceutical and its kinetic model provide a noninvasive method for the assessment of liver function. Eighteen patients were studied: seven with hepatoma, eight with liver metastases, four with cirrhosis (two had concurrent hepatoma and one chronic active hepatitis), and one patient with acute fulminant non-A, non-B hepatitis. Technetium-99m NGA liver imaging provided anatomic information of diagnostic quality comparable to that obtained with other routine imaging modalities, including computed tomography, angiography, ultrasound, and [Tc]sulfur colloid scintigraphy. Kinetic modeling of dynamic [Tc]NGA data produced estimates of standardized hepatic blood flow, Q (hepatic blood flow divided by total blood volume), and hepatic binding protein concentration, [HBP]. Clinical correlation was by classical Child-Turcotte criteria (CTC). Significant rank correlation was obtained between [HBP] estimates and CTC scores (rs = -0.72, p = 0.001). This correlation supports the hypothesis that [HBP] is a measure of functional hepatocyte mass. The combination of decreased Q and markedly reduced [HBP] may have prognostic significance; all three patients with this combination died of hepatic failure within 6 wk of imaging.

Adult↗
PubMed1984

The mechanism of action of insulin on phospholipid metabolism in rat adipose tissue. Requirement for protein synthesis and a carbohydrate source, and relationship to activation of pyruvate dehydrogenase.

We studied certain metabolic requirements for insulin-induced increases in phospholipids, and the relationship of phospholipid changes to the insulin-induced activation of pyruvate dehydrogenase, in rat adipocytes and fat pads in vitro. Increases in the contents of phosphatidylinositol and phosphatidylserine mass were maximal in rat fat pads within 10 min of incubation with insulin, and preceded or accompanied measurable increases in pyruvate dehydrogenase activity. In dose-response studies, the contents of these phospholipids and pyruvate dehydrogenase activity increased in parallel in response to increasing concentrations of insulin. Cycloheximide and puromycin inhibited insulin-induced increases in the mass of both of these phospholipids, as well as (in confirmation of previous reports) pyruvate dehydrogenase activity. Effects of insulin on phospholipid metabolism and pyruvate dehydrogenase were found to require an exogenous carbohydrate source, and fructose was nearly as effective as glucose in this regard. Insulin-induced increases in phosphatidylinositol and phosphatidylserine were demonstrated in the mitochondrial fraction, which is also the subcellular locus of pyruvate dehydrogenase. The present findings suggest that there is a relationship between insulin-induced increases in phospholipids and pyruvate dehydrogenase activity, but the nature of this relationship remains to be defined.

Adipose Tissue↗