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N Kaabachi

Publications and source records attributed to N Kaabachi.

At least 19 recordsLinked to original sources
PubMed2006

Apolipoprotein B signal peptide polymorphism: distribution and influence on lipid parameters in Tunisian population.

Apolipoprotein B (apo B) is the major protein component of LDL, VLDL and chylomicrons. Numerous polymorphisms of the apolipoprotein B gene have been described. Particularly, the insertion/deletion polymorphism located in the coding part of the signal peptide of apo B, associated with modification of lipid concentrations and the risk of cardiovascular disease, has been reported in the general population. No such study in the Tunisian population has been performed. The aim of our study was to assess the effect of insertion/deletion polymorphism of the apolipoprotein B gene on lipid levels in a sample of the Tunisian population. A total of 458 unrelated subjects (321 men and 137 women) were included. The insertion/deletion polymorphism was determined by electrophoresis on polyacrylamide gels after PCR amplification. The relative frequencies of the Ins and Del alleles were 0.74 and 0.26, respectively. These frequencies were similar to those found in other Caucasian populations. There was no significant difference in serum TC, TG, and HDL-C levels due to the influence of the genotypes. However, significant variation among the three genotypes was seen for LDL-cholesterol (p<0.001) and apo B (p<0.001) levels. Individuals homozygous for the Del allele had higher levels than individuals homozygous for the Ins allele, while individuals heterozygous for both alleles exhibited intermediate levels. When the data were analyzed in men and women separately, a similar effect was seen in both groups. Our results show that distribution of apo B insertion/deletion polymorphism in Tunisians is similar to other Caucasian population and confirm the reported association with serum LDL-cholesterol and apo B concentrations.

Adult↗
PubMed2006

Apolipoprotein E polymorphism in the Tunisian population: frequency and effect on lipid parameters.

OBJECTIVES: We determined the frequencies of apolipoprotein E (apo E) gene alleles and examined the association between apo E polymorphism and lipid parameters in a sample of the Tunisian population. DESIGN AND METHODS: Apo E polymorphism was investigated using PCR, and plasma lipid parameters were measured in 122 men and 111 women aged 35 to 87 years. RESULTS: The allele frequencies were epsilon2: 7.3%, epsilon3: 84.6%, and epsilon4: 8.1%. Apo E polymorphism was associated with significant differences (P<0.001) in total cholesterol, apo B and LDL cholesterol in both men and women. epsilon2 carriers had the lowest mean total cholesterol, apo B and LDL-C concentrations, and subjects with the epsilon4 allele had the highest levels. Triglycerides levels increased with the epsilon4 allele, but this did not reach statistical significance. These results remained unchanged after adjustment for age, body mass index, sex, hypertension, diabetes and smoking. However, in obese subjects (BMI>30 kg/m2), TG concentrations were significantly lower in individuals homozygous for the epsilon3 allele compared to those with the alleles epsilon2 or epsilon4. CONCLUSION: In this sample of the Tunisian population, the distribution of apo E gene alleles is similar to that observed in Southern European populations with low prevalence of the epsilon4 allele. Variations in the apo E gene play a role in determining plasma lipid levels. These data also suggest that effects of apo E alleles on lipids levels are partly dependent on environmental variables such as BMI. These findings highlight the importance of the gene/environment interaction on the deleterious effect of obesity on cardiovascular risk factors.

Adult↗
PubMed2006

Clinical and mutational investigations of tyrosinemia type II in Northern Tunisia: identification and structural characterization of two novel TAT mutations.

Tyrosinemia type II or Richner-Hanhart Syndrome (RHS) is an autosomal recessive disorder characterized by keratitis, palmoplantar keratosis, mental retardation, and elevated blood tyrosine levels. The disease is due to a deficiency of hepatic cytosolic tyrosine aminotransferase (TATc), an enzyme involved in the tyrosine catabolic pathway. Because of the high rate of consanguinity this disorder seems to be relatively common among the Arab and Mediterranean populations. RHS is characterized by inter and intrafamilial phenotypic variability. A large spectrum of mutations within TATc gene has been shown to be responsible for RHS. In the present study, we report the clinical features and the molecular investigation of RHS in three unrelated consanguineous Tunisian families including 7 patients with confirmed biochemical diagnosis of tyrosinemia type II. Mutation analyses were performed and two novel missense mutations were identified (C151Y) and (L273P) within exon 5 and exon 8, respectively. The 3D-structural characterization of these mutations provides evidence of defective folding of the mutant proteins, and likely alteration of the enzymatic activity. Phenotype variability was observed even among individuals sharing the same pathogenic mutation.

Adult↗
PubMed2006

[Homocysteinemia and coronary artery disease: a case-control study in a Tunisian population].

We have determined the prevalence of hyperhomocysteinemia and tested its relationship with coronary heart disease in Tunisian patients. The study included 70 angiogrphically proven coronary patients and 140 age- and sex-matched healthy subjects. Plasma homocysteine folate and vitamin B12 were analyzed by immunoenzymatic methods. Hyperhomocysteinemia was considered for plasma homocysteine concentration >17 micromol/L. Mean plasma homocysteine concentration and hyperhomocysteinemia prevalence were significantly (p<0.001) higher in patients (16.3 +/- 7.9 micromol/L and 29%) than controls (12.6 +/- 4.0 micromol/L and 10%). The association between hyperhomocysteinemia and coronary heart disease persisted after adjusting on main cardiovascular risk factors (multi adjusted odds ratio, 2.99; 95% CI, 1.18-7.59; p=0.02). No association was observed between hyperhomocysteinemia and coronary disease severity and extent. This study showed an independent association between hyperhomocysteinemia and coronary heart disease, suggesting a role of hyperhomocysteinemia in atherothrombogenesis. However, causal relationship is not yet established. Until results of homocysteine-lowering therapy trials become available, hyperhomocysteinemia should be researched and treated in coronary heart disease patients.

Case-Control Studies↗
PubMed2004

Vitamin D deficiency in Tunisia.

This study seeks to estimate the status of serum 25-hydroxyvitamin D [25(OH)D] in a healthy section of the population in Tunisia and to compare the achieved results with other published data. A transverse descriptive inquiry was carried out between January and March 2002. Three hundred and eighty-nine subjects aged 20-60 years were included in the study. A questionnaire was used to investigate clinical characteristics: sunlight exposure to ultraviolet light and, for women, parity, breast feeding, whether or not they wore the veil, and menopause. A dietary investigation estimated calcium and vitamin D intake. Morning fasting blood was collected from each subject for the measurement of the following parameters: serum calcium, phosphorus, albumin, alkaline phosphatase, 25(OH)D, parathyroid hormone (PTH). Hypovitaminosis D was defined by a cut-off of 37.5 nmol/l. The population studied was largely female, for the greater part housewives. The accumulated prevalence of hypovitaminosis D was 47.6%, increasing with age. Hypovitaminosis is highly prevalent in women (P<0.001). Multiparity, menopause, wearing the veil, and calcium and vitamin D dietary intake are factors associated with hypovitaminosis D (P<0.05). Analysis of logistic regression shows that only multiparity and vitamin D dietary intake are independent predictive factors. The status of serum 25(OH)D in Tunisia resembles that in southern European countries rather than in Middle Eastern countries. Insufficient vitamin D diet intake, higher parity and wearing the veil explain this deficiency in Tunisia. Dietary enrichment or supplementation by vitamin D and a more outdoor lifestyle, especially for older people, should be seriously considered as a way to reduce this deficiency in Tunisia.

Adult↗
PubMed2004

[Distribution of cardiovascular risk factors in a Tunisian cohort of 6901 coronary patients].

The Tunisian epidemiological data on cardiovascular disease in the hospital environment are scarce. The aim of this study was to evaluate the frequency of cardiovascular risk factors and their association in patients hospitalised for coronary disease in coronary care units at Rabta, Charles Nicolle, Habib Thameur and Military hospitals, Tunis, over the period 1994-1998. The clinical features of 6901 patients (75.7% men, 3760 myocardial infarction, 3141 unstable angina) on hospital admission were analysed. The prevalence of smoking, dyslipidemia, hypertension, diabetes and obesity was 86; 49.8; 33.9; 40.7 and 15.2% respectively in the men and 12.9; 52.4; 64.6; 53.4 and 29.8% respectively in women. With this risk factor profile Tunisia has to implement a national strategy of primary prevention and heart health promotion in addition to the efforts recently made in secondary prevention of some chronic disease such as hypertension, diabetes and smoking.

Adult↗
PubMed2000

Vitamin E and coronary heart disease in Tunisians.

BACKGROUND: Vitamin E (VE) is thought to be effective in preventing atherosclerosis. However, to date no consistent relationship has been identified between VE and coronary heart disease (CHD). This study was designed to assess the degree of association between VE and CHD in a sample of the Tunisian population. METHODS: Sixty-two angiographically confirmed coronary atherosclerotic patients and 65 age- and sex-matched controls were included. VE was measured in plasma and in the LDL fraction by HPLC. Cholesterol, triglycerides, and phospholipids were measured by enzymatic methods. RESULTS: A trend toward a meaningful decrease of plasma VE was observed in affected patients compared with controls (P: = 0.06). VE concentrations standardized for cholesterol and lipid concentrations were significantly lower (P: <0.02) in coronary patients than in controls (4.35 +/- 1.03 vs 4.82 +/- 1.23 mmol/mol for cholesterol-adjusted VE and 2.35 +/- 0.56 vs 2.66 +/- 0.65 mmol/mol for lipid-adjusted VE, respectively). In the LDL fraction, only cholesterol-standardized VE was significantly lower in cases than controls (3.84 +/- 1.13 vs 4.41 +/- 1.16 mmol/mol). This association between VE and CHD remained unchanged independent of age, sex, smoking habit, hypertension, and diabetes. In CHD patients, lower lipid-adjusted VE was associated with enhanced LDL susceptibility to oxidation but without alteration of the serum fatty acid profile. CONCLUSIONS: These results support the hypothesis that VE plays a role in preventing atherosclerosis.

Adult↗
PubMed1998

[Reference values of urinary orotic acid in a healthy Tunisian population].

BACKGROUND: Orotic acid (OA) is an intermediary metabolite of pyrimidine synthesis. An elevation of urinary orotic acid excretion has been described in congenital defect of the urea cycle enzymes and in primary orotic aciduria. Several techniques have been used to measure OA and many reference values are published without considering age and sex. POPULATION AND METHODS: The reference values of urinary OA excretion, expressed in mumol/mmol of creatinine, are reported in a healthy Tunisan population using a colorimetric method. The study included 20 men and 20 women (age = 31 +/- 11 years) and 30 children aged from 3 days to 8 years. RESULTS: There was a significant increase (P < 0.01) of urinary OA excretion in women (4.38 +/- 1.35) compared to men (3.26 +/- 0.80) and of children (5.03 +/- 1.14) compared to adults (3.82 +/- 1.24). Urinary OA excretion was significantly higher among children aged less than 1 year compared to older children. CONCLUSION: It is necessary for every laboratory practicing this kind of exploration to have its own norms which depend on both age and sex.

Adult↗
PubMed1998

Methylmalonic acidaemia with bilateral globus pallidus involvement: a neuropathological study.

A 16-month-old boy was hospitalized because of a 1-day history of severe ketoacidosis with lethargy, hypotonia, vomiting, and important dyspnoea. Organic acid assay by gas chromatography-mass spectrometry confirmed the diagnosis of methylmalonic acidaemia (MMA). On the sixteenth day, he developed an acute extrapyramidal disorder. The CT scan of the brain disclosed bilaterally symmetric lucency of basal ganglia. He died at 17 months of age. Post-mortem neuropathological examination, showed severe necrosis with spongiosis, cystic cavitation and numerous lipid-laden macrophages of the globi pallidi, and mild spongiosis of subthalamic nuclei, mammillary bodies, portion of internal capsule adjacent to globus pallidus, superior cerebellar peduncles and tegmentum of brainstem. Pallidal infarction, a focal ischaemic lesion, demonstrates that ischaemia/energy depletion may be important in the etiology of the neuropathology of MMA.

Cobamides↗
PubMed1998

Dihydropteridine reductase deficiency in a large consanguineous Tunisian family: clinical, biochemical, and neuropathologic findings.

We report the case of a large consanguineous Tunisian family of seven siblings suffering from dihydropteridine reductase deficiency with either typical clinical, biochemical, or autopsy findings. Two cousins also were reported to have the same symptoms. This metabolic disorder is characterized by severe microcephaly, psychomotor regression, and progressive basal ganglia calcifications. Dihydropteridine reductase assay on samples collected from the two brothers still alive did not show measurable activity. The sister and four brothers died between the ages of 3 years and 7 years. A neuropathology study done on the sister showed diffuse demyelination throughout the white matter and spongy vacuolation in the subthalamic nuclei, the superior cerebellar peduncles and the tegmentum tracts of the brain stem. The anterointernal part of the putamen was completely necrotic with nearly total nerve cell loss. Abnormal vascular proliferation and calcification of the walls of small, medium, and large arteries and veins, as well as diffusely scattered pericapillary and isolated calcospherites, were seen in this necrotic region. We think that folate deficiency may be involved in the pathogenesis of the basal ganglia calcification.

Basal Ganglia Diseases↗
PubMed1995

[Zincemia, cupremia and infection in malnourished children].

BACKGROUND: Serum copper and zinc levels are decreased in malnourished and infected children. The role of either malnutrition or infection remains undetermined. POPULATION AND METHODS: Serum zinc and copper concentrations were measured by atomic absorption spectrophotometry in 31 malnourished infants aged 1 to 26 months and 28 eutrophic infants aged 3 to 22 months. Fourteen infants of the first group and 10 of the second were infected at the time of study. RESULTS: Serum zinc and copper levels were significantly decreased in infants with malnutrition (zinc: 66 +/- 32 micrograms/dl and copper: 81 +/- 51 micrograms/dl versus 108 +/- 26 and 185 +/- 21, respectively, in eutrophic infants) (p < 0.001). These levels were still lower in those malnourished infants who were infected (zinc: 49.5 +/- 18 micrograms/dl and copper: 63.5 +/- 37 micrograms/dl versus 81.56 +/- 35 and 94 +/- 56 in non infected patients) (p < 0.02). CONCLUSIONS: Infection increases the risk of low serum zinc and copper concentrations seen in malnourished children. This factor must be taken in account when treating malnutrition.

Analysis of Variance↗
PubMed1994

Clinical and pathological study of three Tunisian siblings with L-2-hydroxyglutaric aciduria.

This report describes three brothers belonging to a consanguineous family suffering from a progressive neurological disorder associated with L-2-hydroxyglutaric aciduria. Clinically this disorder is characterized by childhood onset, pyramidal signs, cerebellar and pseudobulbar syndromes and epilepsy. Pathological examination of the brain in the oldest patient, who died at the age of 30 years, showed bilateral and diffuse spongiosis with notable cystic cavitations of the cerebral white matter without abnormal storage in neurons and glial cells. We consider that these findings are related to L-2 hydroxyglutaric aciduria. To our knowledge this present case represents the first to be reported with neuropathological examination.

Adolescent↗