BCL11A enhancer haplotypes and fetal hemoglobin in sickle cell anemia.

BACKGROUND: Fetal hemoglobin (HbF) levels in sickle cell anemia patients vary. We genotyped polymorphisms in the erythroid-specific enhancer of BCL11A to see if they might account for the very high HbF associated with the Arab-Indian (AI) haplotype and Benin haplotype of sickle cell anemia. METHODS AND RESULTS: Six BCL112A enhancer SNPs and their haplotypes were studied in Saudi Arabs from the Eastern Province and Indian patients with AI haplotype (HbF ~20%), African Americans (HbF ~7%), and Saudi Arabs from the Southwestern Province (HbF ~12%). Four SNPs (rs1427407, rs6706648, rs6738440, and rs7606173) and their haplotypes were consistently associated with HbF levels. The distributions of haplotypes differ in the 3 cohorts but not their genetic effects: the haplotype TCAG was associated with the lowest HbF level and the haplotype GTAC was associated with the highest HbF level and differences in HbF levels between carriers of these haplotypes in all cohorts were approximately 6%. CONCLUSIONS: Common HbF BCL11A enhancer haplotypes in patients with African origin and AI sickle cell anemia have similar effects on HbF but they do not explain their differences in HbF.

Vascular endothelial growth factor A polymorphism and risk of Kaposi's sarcoma herpesvirus viremia in kidney allograft recipients.

BACKGROUND: Kaposi's sarcoma herpesvirus (KSHV) causes Kaposi's sarcoma (KS), primary effusion lymphoma, and multicentric Castleman's disease in immunocompromised patients including allograft recipients. Detection of KSHV DNA in blood, as well as host genetic polymorphisms has been found to be associated with an increased risk for KS. We investigated an association between single nucleotide polymorphisms (SNPs) in vascular endothelial growth factor A (VEGFA) gene region and KSHV viremia in kidney transplant recipients (KTR) in Saudi Arabia. METHODS: In total, 152 KTR who have survived kidney transplantation for at least 6 months were included in the study. KSHV viremia was determined by real-time polymerase chain reaction (PCR). Genotyping of SNPs in the VEGFA region was performed by PCR and direct sequencing, as well as by restriction fragment length polymorphism. RESULTS: KSHV DNA was detected in 28.9% (n = 44) of the study population. The A-allele at position C172A VEGFA gene promoter region was found to be associated with KSHV viremia (odd ratio [OR] = 4.8, P = 0.005). In addition, the G-allele at position C+405G in the 5'-untranslated region was associated with KSHV viremia in women, but not in men (OR = 3.98, P = 0.004). CONCLUSIONS: Our results suggest an association of VEGFA polymorphisms with KSHV viremia among KTR in this study population. A limitation of our study is that the results can only be predicated for patients 6 months after kidney transplantation and should be validated in another cohort with larger sample size.

Haematological, lipid profile and other biochemical parameters in normal and hypertensive subjects among the population of the eastern province of Saudi Arabia.

OBJECTIVE: To determine the lipid profile complete blood count and other biochemical parameters in normotensive and hypertensive individuals. DESIGN: Cross-sectional population-based epidemiological household survey. SETTING: Population sample of the Eastern Province of Saudi Arabia. RESULTS: Hypertensive individuals had significantly higher mean levels of glucose, Tc, LDL-c, HDL-c, triglycerides and HBAIc, compared to normotensive individuals while there were no significant difference in the mean levels of Apo AI and Apo B. Within the same group there were variations in the levels of certain parameters between male and female. While the mean levels of haemoglobin, WBC and platelets were significantly higher in the hypertensive group compared to normotensive, there were no significant differences between these two groups in the levels of RBC, MCV, HCT, MCH and MCHC. However, the mean levels haemoglobin, RBC count and HCT were significantly higher in male compared to female within the same group with no significant difference in levels of WBC, MCV, MCH and MCHC. Furthermore, the mean concentration of platelets was significantly higher in females compared to male within the same group. Hypertensive individuals had significantly higher serum sodium, chloride and calcium levels but a significantly lower potassium level when compared to normotensive with no siginificant differences between male and female within the same group. CONCLUSION: The lipid and electrolyte profile of hypertensive individuals differ from that of normotensive individuals in this population. This study has contributed towards establishing the normal values for a number of parameters involved in the aetiology of cardiovascular diseases in the population of Eastern province.

Cimetidine enhances the hepatoprotective action of N-acetylcysteine in mice treated with toxic doses of paracetamol.

Paracetamol, in toxic doses, is associated with extensive liver damage. This represents one of the common causes of morbidity and mortality in drug poisoning cases. This study was undertaken to investigate the possible potentiation of the hepatoprotective action of N-acetylcysteine (NAC) by cimetidine (CMD), an inhibitor of hepatic microsomal oxidative enzymes. The effects of NAC, cimetidine and the two in combination, administered 2 h post-paracetamol dose, on mortality, plasma glutamic oxaloacetic (GOT) and glutamic pyruvic (GPT) transaminase activities and hepatic reduced glutathione (GSH) levels were investigated in mice 24 h after treatment with a single oral dose of paracetamol (400 mg/kg). Both NAC and cimetidine caused a partial improvement of survival rate, plasma GOT and GPT activities. In addition, they prevented the depletion of hepatic GSH contents. However, concomitant administration of NAC and cimetidine produced a 100% survival rate and a marked reduction in plasma GOT and GPT activities to within the normal range, while significantly raising hepatic GSH concentrations to values close to those measured in saline-treated control animals. It is therefore concluded that cimetidine and N-acetylcysteine may have an additive hepatoprotective action in the treatment of paracetamol overdose.

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.

Effects of glucose-6-phosphate dehydrogenase deficiency upon sickle cell anaemia.

The levels of glycated haemoglobin, fetal haemoglobin and methaemoglobin in 618 Saudi subjects were determined. A statistically significant decrease in the percentage of glycated haemoglobin was observed in all haemoglobinopathic groups studied in comparison to normal controls. However, there was no significant difference in the percentage of glycated haemoglobin in patients with sickle cell anaemia when compared with those sickle cell subjects who were also glucose-6-phosphate dehydrogenase deficient. This suggests that there is little survival advantage or disadvantage in the combination of glucose-6-phosphate dehydrogenase deficiency and sickle cell anaemia.

Fructosamine in HbS and G6PD-deficient Saudi Arabs in the Eastern Province of Saudi Arabia.

Plasma fructosamine, total proteins and albumin were estimated in a group of 77 sickle cell anaemia and 32 glucose-6-phosphate dehydrogenase (G6PD)-deficient Saudi Arabs and the results compared with those obtained in a group of 30 normal controls. The mean values of fructosamine in the sickle cell anaemia and G6PD-deficient patients were not statistically different from those of the controls. The mean values of the total proteins and albumin were also not significantly different from those of the normal group. It is concluded that fructosamine level is not affected by sickle cell anaemia and G6PD deficiency, and provides a useful tool for monitoring diabetic patients in regions with high prevalence of haemoglobinopathies and G6PD deficiency.

Common G6PD variant from Saudi population and its prevalence.

Biochemical characterization of erythrocyte glucose-6-phosphate-dehydrogenase from 18 unrelated deficient Saudi Subjects from Al-Hassa and Al-Qatif areas of the Eastern Province was carried out according to WHO procedures. This had led to the identification of one genetically determined common variant, "G6PD Mediterranean". The overall prevalence rate of this deficiency in these areas was determined to be in excess of 42%. None of the subjects studied displayed any sign of favism, a condition usually associated with G6PD Mediterranean, which is characterized by a very low intracellular enzyme activity.

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.

Thermodynamic parameters associated with the binding of adrenalin and norephedrine to heparin.

Pulse radiolysis has been used to determine the thermodynamic parameters (delta G', delta H' and delta S') governing the binding of adrenalin and norephedrine to heparin. These complexes were completely dissociated by increasing concentrations of inorganic salts. Lower concentrations of divalent cations (e.g. Ca2+) than of monovalent cations (e.g. Na+) were necessary to effect dissociation of the complex. For each interaction an increase in drug binding occurred as the temperature was increased from ambient. However, a transition temperature was observed (48 degrees C) above which the drug was progressively released as the temperature was increased. These observations are discussed in terms of conformational changes induced in the polymer below and above its melting temperature.

A pulse radiolysis study of the interaction of ephedrine with carrageenans.

Pulse radiolysis has been used to determine the thermodynamic parameters (delta G', delta H' and delta S') governing the binding of ephedrine to three carrageenans. For each interaction an increase in drug binding occurred as the temperature was increased from ambient. However, a transition temperature was observed (49 degrees C) above which the drug was progressively released as the temperature was increased. These observations are discussed in terms of conformational changes induced in the polymers below and above their melting temperatures.

Paracetamol-induced hepatotoxicity: lack of enhancement of the hepatoprotective effect of N-acetylcysteine by sodium sulphate.

The potential role of sodium sulphate in possible enhancement of the hepatoprotective action of N-acetylcysteine (NAC) in paracetamol (PCM) overdose was examined. The effects of sodium sulphate (200 mg/kg) in combination with NAC (400 mg/kg) administered intraperitoneally 2 h post-PCM dose, on mortality rate and plasma activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were investigated in mice 24 h after receiving a single oral dose of 400 mg/kg PCM. In addition, the effect on the mortality rate of PCM-treated animals of co-administering 400 mg/kg sodium sulphate with NAC (200 or 400 mg/kg) was also studied. NAC alone caused a marked reduction in the mortality rate of PCM-treated mice and a sharp drop in their plasma AST and ALT activities to near normal values. However, no additional reduction in plasma levels of AST and ALT was observed when sodium sulphate was co-administered with NAC. Similarly, sodium sulphate (200 mg/kg) administered alone to PCM-treated mice had no effect on the high mortality rate or the elevation in plasma AST and ALT activities observed in these animals. Furthermore, increasing the dose of sodium sulphate to 400 mg/kg did not influence the mortality rate. It is therefore concluded that sodium sulphate neither protects against paracetamol-induced hepatotoxicity nor enhances the hepatoprotective action of N-acetylcysteine.

A comparative study of glycosylated haemoglobin level in the Arabian camel (Camelus dromedarius) during different seasons.

1. The extent of haemoglobin glycosylation from 60 camels has been determined (4.39%) in blood samples drawn during winter. 2. Phosphate (9.45 mg/dl), DPG (2.9 mumol/ml) and glucose (138 mg/dl) levels were also recorded. 3. In addition the P50 at pH 7.4 was measured (22.8 Torrs). 4. The data obtained compared with human blood levels and with levels reported for camels during summer sampling. 5. Despite the fact that camels have higher blood glucose levels than humans, the extent of glycosylation is much less in camel blood than in human blood.

A comparative study of enzyme profile of camel (Camelus dromedarius) hump and sheep (Ovis aries) tail tissues.

1. The activities of phosphoenolpyruvate carboxykinase, malic enzyme, NAD+ and NADP+ isocitrate isocitrate dehydrogenase, glucose-6-phosphate dehydrogenase, lactate dehydrogenase and pyruvate kinase were assayed in homogenate of camel hump and sheep tail tissues. 2. In addition the levels of glucose, cholesterol, total protein and total lipids in these tissues were measured. 3. Results obtained were utilized to compare the state of metabolism of adipose tissue of camel hump to that of sheep tail, and to shed some light on possible contribution of these tissues toward blood glucose level.

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.

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.

Percentage glycosylated haemoglobin in normal, G6PD deficient and HbSS Saudi Arabs.

Reference values have been established for erythrocyte glycosylated haemoglobin levels in a normal Saudi population and in subjects with various haematological disorders. The mean glycosylated haemoglobin levels (SE) were 7.28% (0.039) for normal, 6.04% (0.057) for G6PD deficient, 4.40% (0.081) for homozygous sickle cell, and 6.44% (0.109) for heterozygous sickle cell subjects. Values of 6.26% (0.103) and 4.75% (0.127) for glycosylated haemoglobin were determined for heterozygous and homozygous sickle cell subjects with G6PD deficiency, respectively. Statistical analysis of the data shows significant differences in the extent of glycosylation between G6PD deficient, HbSS and normal controls. Where possible the results are compared to values reported for other populations.