Apolipoprotein E polymorphism and clinical disease phenotypes in Arab patients with schizophrenia.

Background: Apolipoprotein E (APOE) is polymorphic, and may be involved in the pathogenesis and clinical expression of schizophrenia. This study aimed to investigate the frequency of specific APOE genotypes and alleles in a schizophrenic Arab population and evaluate the association of specific APOE types with clinical phenotypes of the disease.

Subjects And Methods: Two age-matched groups of subjects were studied: (1) healthy controls, n = 165; (2) patients with schizophrenia (SZ), n = 207.

Body mass and atherogenic dyslipidemia as major determinants of blood levels of B-type natriuretic peptides in Arab subjects with acute coronary syndromes.

Introduction: The plasma B-type natriuretic peptide (BNP) level is elevated in cardiac ischemia and may be useful in assessing prognosis in acute coronary syndromes (ACS). This study aimed to: (1) establish BNP levels and its determinants in a healthy Gulf Arab population and in a group of patients with acute myocardial infarction and (2) investigate associations between BNP levels and markers of myocardial damage (ejection fractions, cardiac troponin I [cTnI] levels) and inflammation (serum C-reactive protein [CRP]).

Subjects And Methods: We studied 2 groups of Arab subjects: (1) Healthy control (HC), 142 healthy control subjects; (2) Coronary heart disease (CHD), 257 patients with proven acute myocardial infarction within 1 day of admission.

Association of blood levels of C-reactive protein with clinical phenotypes in Arab schizophrenic patients.

Schizophrenia may be associated with inflammatory reactions and C-reactive protein (CRP) is a nonspecific serum protein marker for persisting inflammatory states. This study aimed to assess concentrations of high sensitivity CRP (hsCRP) in schizophrenic Arab patients and evaluate the relationships of hsCRP levels with aspects of clinical phenotypes of the disease. Two age-matched groups of subjects were studied: (1) healthy controls, HC, n=165; (2) patients with schizophrenia, SZ: n=207.

Insulin-like growth factor (IGF)-I, IGF-II and IGF-binding protein (IGFBP)-3 levels in Arab subjects with coronary heart disease.

Objective: Insulin-like growth factors (IGF-I, IGF-II) and their binding protein (IGFBP-3) may be risk markers for coronary heart disease (CHD). This study aimed to assess the levels and determinants of the serum levels of IGF-I, IGF-II and IGFBP-3 in Arab patients with established CHD.

Material And Methods: Two groups of subjects were matched for age, gender, BMI and waist-hip ratio (WHR): (i) CHD (n = 105), median age 51.

Associations of blood levels of insulin-like growth factor (IGF)-I, IGF-II and IGF binding protein (IGFBP)-3 in schizophrenic Arab subjects.

Background: Insulin-like growth factors (IGFs) are believed to be important in brain development and repair following neuronal damage. It is also speculated that IGFs are involved in the association of foetal and pre-adult growth with schizophrenia (SZ).

Methods: The aim of this study was to assess levels of IGF-I, IGF-II and IGF binding protein (IGFBP)-3 and their associations in male Arab patients with SZ (n=53) and healthy control subjects (HC; n=52).

Associations of blood homocysteine concentrations in Arab schizophrenic patients.

Background: This study aimed to evaluate the blood homocysteine concentration in Arab patients with schizophrenia and assess its associations with clinical phenotypes of the disease.

Subjects And Methods: Two age-matched groups of subjects were studied: (1) Healthy Controls, HC, n=165; (2) patients with schizophrenia, SZ: n=207. Each subject was evaluated with a standard questionnaire for age at disease onset, family history, disease severity and outcome.

Associations of apolipoprotein E polymorphism with low-density lipoprotein size and subfraction profiles in Arab patients with coronary heart disease.

The APOE gene locus has 3 major alleles, E3, E4 and E2, which variably influence coronary heart disease (CHD) risk. Plasma low-density lipoprotein (LDL) profile, another major CHD risk factor, is characterized on the basis of size and density into 2 main patterns: large buoyant LDL and small dense LDL. The latter has also been linked with increased CHD risk.

Apolipoprotein E polymorphism and lipoprotein levels in a Gulf Arab population in Kuwait: a pilot study.

Background: APOE polymorphism is believed to confer susceptibility to coronary heart disease (CHD) and Alzheimer's disease. It is well known that patterns of APOE polymorphisms differ between populations and ethnic groups, although most of the data available so far have been in whites.

Subject And Methods: We evaluated the frequencies of APOE genotypes and their relationships with serum levels of lipids, lipoproteins and apolipoproteins in two groups of Gulf Arab citizens: a control population of healthy voluntary blood donors (n=106), and a group of patients presenting to the lipid clinic for the first time with combined hyperlipidaemia (CH) (n=41).

The relationship of APOE genetic polymorphism with susceptibility to multiple sclerosis and its clinical phenotypes in Kuwaiti Arab subjects.

Background: The possible pathogenetic relationship between APOE genetic polymorphism and susceptibility to a variety of neurodegenerative disorders, including multiple sclerosis, is controversial. Previous studies have been conducted in Caucasian subjects, with little or no data on subjects from the Arabian Gulf. We compared the frequencies of specific APOE genotypes and alleles in patients with multiple sclerosis (MS) with frequencies observed in a healthy control Kuwaiti Arab population to relate APOE frequencies with specific identifiable clinical features of the disease.

Serum lipoprotein (a) concentrations among Arab children: a hospital-based study in Kuwait.

Elevated lipoprotein (a) [Lp(a)] is an independent risk factor for premature atherosclerosis and coronary heart disease, both of which are prevalent among Kuwaitis. Our objective was to measure serum lipids, including Lp(a), in Arab children and compare them with values reported for other ethnic groups. To that end, serum concentrations of Lp(a), total cholesterol [T-CHOL], high density lipoprotein [HDL], low density lipoprotein [LDL], and triglyceride [TG] were assessed in 103 Arab children.

Analysis of the D1S80 (pMCT118) VNTR locus polymorphism in a native Kuwaiti population by the polymerase chain reaction.

We have determined the allele and genotype frequencies at the hypervariable locus D1S80 in a native Kuwaiti population using the polymerase chain reaction technique and subsequent high resolution gel electrophoresis. In a sample of 200 individuals, 21 alleles and 57 genotypes were detected. The alleles with 18 and 24 repeat units were most common with frequencies of 0.

HLA-DQ alpha allele and genotype frequencies in a native Kuwaiti population.

We report the allele and genotype frequencies in a sample of an unrelated native Kuwaiti population determined by the use of polymerase chain reaction (PCR) and reverse dot-blot analysis. This technique, involving the use of commercially available AmpliType HLA-DQ alpha forensic DNA amplification and typing kit, has permitted the definition of six alleles and 21 genotypes in a sample of 220 people. The allelic frequencies are in the range 5.

Chemical modification of rat liver cytosolic NADP(+)-linked isocitrate dehydrogenase by N-ethylmaleimide. Evidence for essential sulphydryl groups.

Incubation of rat liver cytosolic isocitrate dehydrogenase with N-ethylmaleimide (NEM) resulted in the inactivation of the enzyme following pseudo-first order kinetics. Isocitrate affords considerable protection against inactivation whereas NADP+ enhances modification of the enzyme, suggesting localization of the modified group at the active site. Correlation of loss of activity with incorporation of [14C]NEM indicated that two sulphydryl residues/sub-unit are modified of which only one is shown to be involved in catalysis.

Purification and partial characterisation of NADP(+)-linked isocitrate dehydrogenase from rat liver cytosol.

NADP(+)-linked isocitrate dehydrogenase from rat liver cytosol was purified (approximately 135-fold) to apparent homogeneity in 27% yield. The purified enzyme has specific activity of 73 units.mg-1.

Cyclic AMP and free fatty acids in the longer-term regulation of pyruvate dehydrogenase kinase in rat soleus muscle.

Starvation increased pyruvate dehydrogenase (PDH) kinase activity in extracts of freshly excised rat soleus 2.2-fold (from 0.6 min-1 in fed rats to 1.

The effect of a plants mixture extract on liver gluconeogenesis in streptozotocin induced diabetic rats.

We have previously reported on plant mixture extract comprising of Nigella sativa, Myrrh, Gum Olibanum, Gum Asafoetida and Aloe to have a blood glucose lowering effect. The present study with streptozotocin diabetic rats is focussed on the mechanism of action, specifically on a) hepatic gluconeogenesis b) activity of key gluconeogenic enzymes, pyruvate carboxylase (PC) and phosphoenol-pyruvate carboxykinase (PEPCK). Similar studies using a biguanide, phenformin, have been conducted to compare the mode of action of these two compounds.

Modulation of pyruvate dehydrogenase kinase activity in cultured hepatocytes by glucagon and n-octanoate.

The activity of pyruvate dehydrogenase kinase in extracts of mitochondria from rat hepatocytes cultured for 21 h in medium 199 was increased 2.5-fold by the presence of 55 nM-glucagon and 1 mM-sodium n-octanoate in the culture medium. The change was comparable with that induced in vivo by 48 h starvation.

Purification and properties of a protein activator of phosphorylated branched-chain 2-oxo acid dehydrogenase complex.

The protein activator of phosphorylated branched-chain 2-oxo acid dehydrogenase complex was purified greater than 1000-fold from extracts of rat liver mitochondria; the specific activity was greater than 1000 units/mg of protein (1 unit gives half-maximum re-activation of 10 munits of phosphorylated complex). Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis gave two bands (Mr 47700 and 35300) indistinguishable from the alpha- and beta-subunits of the branched-chain dehydrogenase component of the complex. On gel filtration (Sephacryl S-300), apparent Mr was 190000.

Dephosphorylation and reactivation of phosphorylated purified ox-kidney branched-chain dehydrogenase complex by co-purified phosphatase.

The branched-chain 2 oxoacid dehydrogenase complex has been purified from well-washed ox-kidney mitochondria together with branched-chain dehydrogenase kinase. The complex was inactivated and phosphorylated by ATP in about 5 min at 30 degrees C. After hydrolysis of ATP by a contaminating ATPase (5-10 min) the complex was dephosphorylated and reactivated.

On the mechanism of NADP+-linked isocitrate dehydrogenase from heart mitochondria. II. The transient-state kinetics of the oxidative decarboxylation of isocitrate.

The kinetics of a single turnover of enzyme-catalysed oxidative decarboxylation have been studied by mixing a stoichiometric complex of enzyme, isocitrate and Mg2+ with large concentrations of NADP+ in a stopped-flow apparatus, and monitoring the formation of NADPH by fluorescence measurements. A transient is revealed that exhibits enhanced nucleotide fluorescence and is not detectable by light absorption measurements. The results obtained with the largest NADP+ concentrations, such that the product NADPH is largely displaced from its enzyme complex, show that a step that precedes the release of free NADPH is rate-limiting in the oxidative decarboxylation reaction under conditions of catalytic cycling.

On the mechanism of NADP+-linked isocitrate dehydrogenase from heart mitochondria. I. The kinetics of dissociation of NADPH from its enzyme complex.

The kinetics of dissociation of NADPH from its complex with isocitrate dehydrogenase, and from the abortive complex of enzyme, Mg2+, isocitrate and NADPH, have been studied in phosphate and triethanolamine buffers by means of rapid fluorescence measurements. The reactions are complex, and it is suggested that a conformational equilibrium of each of the complexes is involved, and that this conformational change is also responsible for a slow approach to the steady-state rate of oxidative decarboxylation observed previously in triethanolamine buffer under certain conditions (K. Dalziel, N.