Ragheb F. Atmeh

Seroprevalence of Toxocara canis antibodies in humans in northern Jordan

Sera of 699 individuals, aged between 5-24 years, from the Irbid area, Jordan, were tested for Toxocara canis antibodies using an ELISA-IgG test. Crude prevalence was 10.9% (76 of 699) but age-adjusted prevalence was 14.3%. The highest prevalence was observed in females aged 5-9 years, 23.3% (7 of 30), and males of 15-19 years of age, 19.5% (16 of 82). The lowest prevalence was observed in females aged 20-25 years, 5.2% (8 of 155). Significant differences (P < 0.05) between the prevalences of the toxocaral antibodies in males and females were observed in the age groups 5-9, 15-19 and 20-24 years. The trend of prevalence in relation to age was different according to sex.

Isolation of high density lipoprotein subclasses by electrofiltration and their chemical components.

Abstract The exact role of high density lipoprotein in atheroprotection is not well understood yet due to its complex nature; it comprises more than ten subclasses that vary in size, composition, and function. Isolation and characterization of these subclasses is an important step for further studies addressing their functions in health and disease. In this work, we present a novel method that is relatively simple and efficient for isolation of high density lipoprotein subclasses. The method depends on fractional filtration of the subclasses through a preformed gel membrane system under the effect of an electric field, where the stepwise isolation of the subclasses depends on differences in their rates of migration in polyacrylamide gel. Using this design, we were able to isolate seven high density lipoprotein subclasses with relative molecular masses of 42,000–50,000; 71,000; 103,000; 124,000; 150,000; 182,000; and 219,000. All the subclasses contained apolipoprotein A-I, phosphatidylcholine, sphingomyelin, free cholesterol, esterified cholesterol, and triacylglycerols. Some fractions of some samples contained the apolipoproteins A-II, C-I, C-II, C-III, and E. A subclass of molecular mass of 106,000 was identified and isolated from a healthy young subject that contained albumin and apoA-I with some free and esterified cholesterol, but with no triacylglycerols. This electrofiltration technique offers a novel tool for isolating pure native high density lipoprotein subclasses in a concentrated form that can be used directly for detailed studies of their physicochemical and physiological properties.

Metabolism of apolipoproteins A-I and A-II in human high-density lipoprotein: a mathematical approach for analysis of their specific activity decay curves

The differential rate equations describing the compartmental model of human high-density lipoprotein (HDL) were integrated by means of Laplace transforms and an exponential equation was obtained for each of the three compartments. These equations were used to fit the observed plasma decay data and give estimates for the rate constants of the system by means of a written computer program. Furthermore, these estimates were used to calculate the exponential constants of the integrated equations. Consequently, the amount of label in any of the intravascular, extravascular, and urine compartments can be calculated as a fraction of the original dose of label at any time point. This method was tested using data for the (AI)HDL subclass because it contains only apolipoprotein A-I as the major apolipoprotein and does not contain apolipoprotein A-II. The calculated plasma and urine radioactivity data were compared with the experimentally obtained data from two normolipoproteinemic subjects and found to be in good agreement. The significance of this method is its application to the analysis of the decay data of the individual apolipoproteins of (AI + AII) HDL subclass where the urinary radioactivity data resulting from the individual apolipoprotein breakdown on the native particle cannot be measured experimentally at present. Such data are essential for the detailed calculation of the kinetic parameters of these apolipoproteins.

Electrophoretic immunodesorption of proteins according to molecular weight by use of a double-membrane system

SummaryA simple method is described for electrophoretic desorption of proteins from antigen-antibody complexes, with more than 90% recovery and without denaturation, after immunosorbent affinity chromatography. Radiolabeled or unlabeled human serum albumin (HSA) and α-1-antitrypsin (AAT), conjugated to rabbit anti-HSA or anti-AAT polyclonal antisera, respectively, were electrophoretically desorbed from Sepharose 4B. In addition, purification and concentration of the major HSA protein band (monomer) of 68 kD from the other oligomeric protein bands were achieved by use of a two-membrane system in a simple electroelution apparatus. The system consisted of an upper cellulose acetate membrane, with pore size 20 nm and separation limit 70 kD, and a lower dialysis cellophane membrane with molecular weight cut-off from 1–50 kD that cnables separation according to size. Furthermore, purification of the monomer HSA or AAT from normal human serum was performed with 92% recovery. Homogeneity was implied by the presence of one band after sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, Western blot, and autoradiography.