Macrophage-HIV interaction: viral isolation and target cell tropism.

Viral isolates were recovered by cocultivation on macrophage colony-stimulatingfactor (MCSF)-treated monocyte target cells from peripheral blood mononuclear cells (PBMCs) in 25 out of 27 patients seropositive or at risk for HIV infection. Frequency of virus recovery was independent of the patient's age, sex, numbers of CD4+ T cells, clinical stage or zidovudine (azidothymidine) therapy. Sixteen out of 19 HIV isolates were serially passaged in MCSF- treated monocytes. Five out of five virus isolates were also passaged in phytohemagglutinin/interleukin-2 (PHA/IL-2)-treated lymphoblasts. In lymphoblasts, no qualitative or quantitative differences were observed between these isolates and human T-cell leukemia virus IIIB (HTLV-IIIB) for (1) release of p24 antigen reverse transcriptase, and infectious virus, (2) induction of typical cytopathic effects (cell syncytia in 3-10% of cells) and cell lysis, (3) frequency of infected cells (5-20% of PBMC) as detected by in situ hybridization for HIV RNA, (4) down-modulation of T cell plasma membrane CD4, and (5) site of progeny virion assembly and budding (plasma membrane only with no intracytoplasmic accumulation of virus). Progeny virus recovered from infected lymphoblasts was fully infectious for other lymphoblasts, but failed to infect MCSF-treated monocytes. Detailed analysis of target cell tropism among HIV isolates showed that HIV isolated in monocytes infected both monocytes and lymphoblasts; progeny virus isolated in lymphoblasts infected only T cells. HIV interacts differently with monocytes and T cells. Understanding this interaction may more clearly define both the pathogenesis of HIV disease and strategies for therapeutic intervention.

A study of the biochemical characteristics of NADP+ isocitrate dehydrogenase from the liver and kidney of the Arabian camel (Camelus dromedarius).

1. NADP+ isocitrate dehydrogenase was partially purified from camel liver and kidney by an FPLC. 2. The specific activity of the purified preparation from liver was 63.5 mumol/min/mg protein and from the kidney was similar, 58.7 mumol/min/mg protein. 3. The enzyme from the two sources were similar in their pH optimum (7.6), electrophoretic mobility and stability to thermal inactivation at 60 degrees C. 4. Heat inactivation was accelerated by oxidized glutathione and cystine and decreased by dithiothreitol, reduced glutathione and cysteine. 5. The molecular weight of the enzyme from both organs was estimated as 60,000 +/- 5000. 6. Divalent metal ions increased the activities of both enzymes, with maximum catalytic activity in the presence of Mn2+ ions.

A comprehensive biochemical analysis of the blood of the camel (Camelus dromedarius).

1. The blood of twenty camels has been analyzed and the levels of eight serum enzymes determined. 2. In addition, PK and G6PD activities in the erythrocytes were assayed. 3. A number of other serum constituents were also measured, including haemoglobin, bilirubin, uric acid, phosphorus, cholesterol, total lipids and glucose. 4. Wherever possible, the values obtained were compared with data for the camel reported in the literature. 5. Where no such values existed, comparisons with other ruminants were drawn.

Purification and comparison of phosphoenolpyruvate carboxykinase from the liver and kidney of the Arabian camel (Camelus dromedarius).

1. Phosphoenolpyruvate carboxykinase was partially purified from camel liver and kidney by ammonium sulphate fractionation, gel filtration and ion-exchange chromatography. 2. The specific activity of the purified preparation from liver was 39.2 mumol/min per mg protein. 3. When isolated from the kidney the specific activity of the enzyme was very much higher 155.5 mumol/min per mg protein. 4. The enzyme from the two sources were similar in their pH optimum which was approx. 7.2 and their relative stability to thermal inactivation at 60 degrees C. 5. The mol. wt of the enzyme from both organs was estimated at 80,000 +/- 5000.

Determination of glycosylated haemoglobin in normal, newborn and diabetic Saudi Arabs.

Colorimetric determinations of glycosylated haemoglobin by the thiobarbituric acid method were carried out in normal adults (n = 142), newly born infants of healthy mothers (n = 81), and in a group of patients with diabetes mellitus (n = 124). The glycosylated haemoglobin level in normal adult males was 4.9%, which is close to that reported for other populations. No correlation was found between age and the levels of glycosylated haemoglobin in males over 10 years old. However, the mean value for glycosylated haemoglobin in cord blood was 4.1%, significantly different from that of adults. The range values for glycosylated haemoglobin in diabetic patients was 7-19%. The mean value for glycosylated haemoglobin was 10.9%, similar to that established in other diabetic populations. Results of colorimetric determinations of glycosylated haemoglobin in the Saudi population compare well with other ethnic groups and, therefore, suggest no ethnic differences in glycosylated haemoglobin levels.

Glycosylated hemoglobin levels in a benign form of sickle cell anemia in Saudi Arabia.

Glycosylated hemoglobin was determined by the thiobarbituric acid method in sickle cell anemia patients from the Eastern Province of Saudi Arabia. The level of glycosylated hemoglobin in a Saudi SS sample (4.36%, SD 0.83) is 90% of that of the sample of normals (4.85%, SD 0.51). This is in contrast with the reported value of glycosylated hemoglobin in an American Black SS sample (3.9%, SD 0.6), which is only 60% of that of the sample of normals (6.6%, SD 0.7). The fetal hemoglobin level in Saudi sickle cell patients was 12.03% (SD 4.84), which is significantly different from that of Americans of African origin at p = 0.001. There was no significant correlation (r = 0.236) between the percentages of glycosylated Hb and Hb F at the 10% confidence level. The reported positive relationship between the percentages of glycosylated Hb and Hb F in American Blacks seems to be valid in the Saudi population only up to the level of 10-12% of fetal hemoglobin. Above this threshold of Hb F no further alleviating effect is seen. The 2,3-diphosphoglycerate value in Saudi Hb SS adults was 21.7 mumol/g (SD 7.4) and accordingly only twice as high as that of normal individuals. The benign clinical course exhibited by Saudi sickle cell patients is reflected by the survival of the RBC as indexed by its content of glycosylated Hb and 2,3-diphosphoglycerate. Moreover 10-12% of fetal hemoglobin in the RBC seems sufficient to ameliorate the severity of this disease in patients from the Eastern Province of Saudi Arabia.