Predictors of autoimmune hemolytic anemia in beta-thalassemia patients with underlying red blood cells autoantibodies.

In beta-thalassemia patients, erythrocyte autoantibodies can remain silent or lead to Autoimmune Hemolytic Anemia (AIHA).The aim of this study was to identify predictors of AIHA in beta-thalassemia patients with positive Direct Antiglobulin Test (DAT), in Tunisia. This longitudinal prognosis study was carried out on beta-thalassemia patients with a positive confirmed DAT. Predictors of AIHA were identified the Kaplan-Meier method. A Cox model analysis was used to identify independent predictors. Among 385 beta thalassemia patients, 87 developed positive DAT (22.6%). Autoimmune hemolytic anemia was occurred in 25 patients. Multivariate analysis showed that AIHA was independently associated with beta-thalassemia intermedia and similar family history of AIHA. Splenectomy in patients with positive DAT was independently associated with an increased risk of AIHA (HR = 6.175, CI: 2.049-18.612, p < 0.001). The risk of developing AIHA was higher during the first 72 transfusions. Autoimmune hemolytic anemia was significantly associated with polyspecific DAT (anti-complement and anti-IgG), blood group AB and prior alloimmunization. Whereas transfusion by phenotypic and leukoreduced blood was a protective factor. In summary, splenectomy after autoimmunization, prior alloimmunization, DAT specificity (IgG with complement), thalassemia intermedia, AB blood group and family history of AIHA were strongly associated with AIHA. Leukoreduced blood transfusion had a proven preventive role.

Association of PON1 and PON2 polymorphisms with PON1 activity and significant coronary stenosis in a Tunisian population.

PON1 and PON2 have attracted considerable attention as candidate genes for coronary heart disease because their enzymes function as key factors in lipoprotein catabolism pathways. We studied the distribution of PON1 and PON2 polymorphisms, including genotyping, lipid profile, and PON1 activity, and their association with PON1 activity and significant coronary stenosis (SCS) in a Tunisian population. PON1 activity was lower in patients with SCS than in controls. It increased with the R allele (QQ < QR < RR) in PON1-192 genotypes and with the L allele (MM < ML < LL) in PON1-55 genotypes. In the presence of metabolic syndrome and diabetes, PON1-192RR and PON2-311CC were associated with an increased risk of SCS and PON1-55MM seems to have lower risk. This association was evident among nonsmokers for PON1-55MM and among smokers for PON1-192RR and PON2-311CC. The GTGC haplotype seemed to increase the risk of SCS compared with the wild haplotype in a Tunisian population.

Association of three polymorphisms of scavenger receptor class BI gene (exon8, exon1, intron5) with coronary stenosis in a coronary Tunisian population.

BACKGROUND: The potential role of scavenger receptor class BI (gene name SCARB1) in the regulation of lipoproteins metabolism and atherosclerosis has attracted considerable interest. We tested the relationship of SCARB1 polymorphisms with significant coronary stenosis (SCS) and lipid profile in a coronary Tunisian population. METHODS: Three SCARB1 polymorphisms (exon8 (C/T), exon1 (G/A), intron5 (C/T)) were studied in 316 Tunisian patients undergoing coronary angiography. SCS was defined as a luminal narrowing of ≥ 50% in at least one major coronary artery. Lipid profile was measured. Genotyping was performed using PCR-RFLP. RESULTS: Individuals with TT genotypes of exon8 were associated with higher concentrations of plasma HDL-C and ApoAI in the group without SCS. Carriers of T allele of exon8 were associated with 41% lower risk of SCS. This protective effect seemed to be particularly significant in women, nondiabetics and nonsmokers. Subjects homozygous for the variant allele of intron5 were significantly associated with an increased risk of SCS, particularly in smokers. AA genotype of exon1 was associated with an increased risk of SCS in diabetics and in patients with metabolic syndrome. The (CAT) haplotype was associated with increase in the risk of SCS compared to the wild haplotype and had a 4-fold greater risk of SCS than patients with haplotype (TGC) which seems to be the most protective against SCS. CONCLUSION: Carriers of T allele of exon8 in SCARB1 seemed to increase HDL-C and ApoAI concentrations and reduce the risk of SCS. The intron5, exon1 and (CAT) haplotype seemed to have an atherogenic effect.

Four polymorphisms of cholesteryl ester transfer protein gene and coronary stenosis in a Tunisian population.

AIMS: The role of cholesteryl ester transfer protein (CETP) in the development of atherosclerosis is under debate. We studied the association of four polymorphisms (Taq1B, I405V, R451Q and A373P) in the CETP gene with lipid profile and coronary artery disease. METHODS: Four CETP polymorphisms were studied in 316 Tunisian patients undergoing coronary angiography. Patients were clinically examined and their lipid profiles were estimated. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism analysis. RESULTS: The 451Q allele, associated with lower high-density lipoprotein-cholesterol (HDL-C) and higher total cholesterol and apolipoprotein B (ApoB) concentrations, was also significantly associated with an increased risk of significant stenosis [odds ratio (OR) = 1.74, 95% confidence interval (CI) 1.15-2.61, P = 0.007]. The B2 allele of Taq1B polymorphism had an increase in HDL-C concentration and was associated with a decreased risk of coronary stenosis, as described earlier. It was also associated with low risk of hypoHDLaemia [OR = 0.615, 95% CI 0.377-1.002, P = 0.035]. No significant effect of different A373P and I405V alleles was found on the lipid profile and on coronary stenosis. When CETP polymorphisms were combined in haplotypes possessing R451Q, A373P, I405V, Taq1B polymorphisms, the 1112 haplotype (where 1 is the wild genotype and 2 represents carriers of the variant allele) seems to be the most protective against significant stenosis (OR = 0.71, 95% CI 0.188-0.983; P = 0.014), whereas 2111 was probably the most atherogenic, with an OR = 2.17, 95% CI 1.06-5.88; P = 0.039. CONCLUSION: The Q allele of the R451Q polymorphism was associated with decreased HDL-C, increased ApoB concentrations and increased risk of coronary stenosis. In haplotype analysis, we found that 1112 seems to be a protective haplotype, whereas 2111 has an atherogenic effect in a coronary Tunisian population.

Association between eight adiponectin polymorphisms, obesity, and metabolic syndrome parameters in Tunisian volunteers.

BACKGROUND: Adiponectin is a plasma protein produced by the adipose tissue, with insulin sensibility, antiinflammatory and antiatherogenic properties. Many adiponectin gene polymorphisms have been described, and their implication in obesity, metabolic syndrome, and cardiovascular diseases was controversial. Our aim was to study the relationship between eight adiponectin polymorphisms (-1391G/A, -1377C/G, 4522C/T, 395 G/A, 276G/T, 639C/T, 45T/G, and +2019delA), metabolic syndrome parameters, and the risk of obesity in Tunisian volunteers. METHODS: We have recruited 169 nonobese [sex ratio=0.594, mean age 43.25±13.12 years; mean body mass index (BMI) 24.73±3.50 kg/m(2)] and 160 obese (BMI≥30 kg/m(2)) (sex ratio=0.221, mean age 48.41±10.92 years; mean BMI 36.6±4.8 kg/m(2)). Genotyping was performed using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). Glucose, insulin, and lipids were measured. BMI and homeostasis model assessment of insulin resistance (HOMA-IR) were calculated. RESULTS: The polymorphisms 276G/T, 639 C/T, 11391 G/A, 11374C/G, and +2019delA seem to contribute to obesity. In fact, adjusted odds ratios (ORs) of obesity associated with mutated genotypes of each polymorphism were, respectively: OR=0.64, P=0.039; OR=1.85, P=0.018; OR=1.68, P=0.044; OR=1.77, P=0.038; and OR=1.94, P=0.010). Mutated genotypes at 639 C/T were associated with higher waist circumference, BMI, and systolic and diastolic blood pressure. In addition, the 11391AA genotype was associated with increased BMI. Concerning 2019delA, the delAdelA genotype was associated with increased HOMA-IR and BMI, suggesting a possible effect of these single-nucleotide polymorphisms (SNPs) on insulin resistance parameters. Mutated genotypes at 276G/T were associated with lower serum insulin concentration and lower systolic and diastolic blood pressure. The other genotypes showed no association with metabolic syndrome parameters. CONCLUSION: Adiponectin gene polymorphisms were associated with obesity and metabolic syndrome parameters in Tunisian volunteers.

Associations between common polymorphisms of adenosine triphosphate-binding cassette transporter A1 and coronary artery disease in a Tunisian population.

BACKGROUND: The adenosine triphosphate-binding cassette transporter A1 (ABCA1) protein plays an important role in the first step of the reverse cholesterol transport system. AIMS: We studied the association of four polymorphisms in the ABCA1 gene (G1051A, G2706A, G2868A and -565C/T) with lipid profile and coronary artery disease. METHODS: Overall, 316 Tunisian patients underwent coronary angiography. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism analysis. Lipid and apolipoprotein concentrations were measured. RESULTS: Only carriers of the G2706A allele were associated with a decreased risk of significant stenosis (odds ratio [OR] 0.66, 95% confidence interval [CI] 0.22-0.92, p = 0.029), without pronounced effects on high-density lipoprotein (HDL) cholesterol. This protective effect was significant in smokers and diabetes. Carriers of the G1051A allele were associated only with increased concentrations of HDL cholesterol (p = 0.032). G2868A and -565C/T did not show any association with lipids or risk of significant stenosis. When ABCA1 polymorphisms were combined in haplotypes possessing G1051A, G2706A, G2868A and -565C/T, (AAGC) seemed to be most protective against significant stenosis (OR 0.5, 95% CI 0.29-0.96, p = 0.048) whereas (GGAT) was probably the most atherogenic (OR 1.26, 95% CI 1.03-1.56, p = 0.025). CONCLUSION: Only the G2706A allele seems to be associated with a reduced risk of significant stenosis without important modification of HDL-cholesterol concentration, and appears to be more protective for smokers and diabetic patients. We found that (AAGC) seems to be a protective haplotype whereas (GGAT) has an atherogenic effect in a Tunisian population.

Rotavirus strain diversity in the centre coast of Tunisia from 2000 through 2003.

An epidemiological survey investigating rotavirus infection in children was undertaken in the coastal region of Tunisia from January 2000 through September 2003. A total of 309 fecal specimens were screened by enzyme-linked immunosorbent assay and latex agglutination assay for the presence of group A rotavirus antigen. The detection rate was 26.2%. Rotavirus outbreaks showed a temperature-dependant pattern (P = .026) but no significant association with rainfall. Rotavirus strains isolated were analyzed by RNA polyacrylamide gel electrophoresis and were characterized antigenically by monoclonal antibodies to the VP6 subgroup. Eight RNA electropherotypes were identified, with 3 long and 5 short different RNA profiles. Among VP6 typeable strains, all isolates with a long electrophoretic pattern carried the subgroup II specificity, whereas those with a short profile belonged to subgroup I. In total, 48 rotavirus-positive samples were analyzed for G and P typing by reverse-transcription polymerase chain reaction. A total of 8 different G and P combinations were found: G1P[8] (35.7%), G1P[6] (21.4%), G2P[4] (4.8%), G3P[4] (4.8%), G4P[6] (4.8%), G8P[8] (4.8%), G3P[8] (2.3%), and G4P[8] (2.3%). Mixed infections were detected in 19.1% of stool samples. The emergence in Tunisia of unconventional types, such as G8VP7 specificity, highlights the need for a continual survey of the uncommon strains in North Africa.

Metabolic syndrome is a risk factor for coronary artery disease in a tunisian population.

BACKGROUND: Metabolic syndrome is a constellation of disorders that produces a high risk of atherosclerosis. The prevalence of metabolic syndrome clearly varies depending on ethnicity. The aim of this study was to investigate the prevalence of metabolic syndrome and its relationship with significant coronary stenosis (SCS) in a Tunisian population. METHODS: Metabolic syndrome was diagnosed according to the International Diabetes Federation criteria. SCS was defined as a luminal narrowing of more or equal to 50% in at least 1 major coronary artery, as judged by coronary angiography. A total of 192 subjects documented by coronary angiography were recruited from the cardiology department. RESULTS: In all, 54.2% (n = 104) of patients presented with metabolic syndrome, with a higher prevalence among women (65.9% vs. 45.5%; P = 0.004). In the subjects with metabolic syndrome, the fasting hyperglycemia was the most common metabolic disorder (86.5%). The risk of SCS increased approximately 3-fold in the presence of metabolic syndrome [odds ratio (OR) = 3.38, P = 0.004]. In addition, SCS risk was increased according to the increase in the number of metabolic syndrome components. The most atherogenic profile was that which assembled five metabolic syndorme components (OR = 4.18, P = 0.001). There was a significant relationship between the homeostasis model of insulin resistance (HOMA-IR) and the risk of SCS in the presence of metabolic syndrome. In fact, the OR of SCS associated with metabolic syndrome was (4.96, P = 0.001) in participants in the highest quartile of HOMA-IR. CONCLUSIONS: This study suggests that metabolic syndrome is a risk factor for SCS. The detection, prevention, and treatment of the underlying risk factors of metabolic syndrome should become an important approach for reduction of the cardiovascular disease burden in our study population.

[Internet use among medical students in Batna (Algeria), Rouen (France), Sousse (Tunisia)]. / Utilisation de l'internet chez les étudiants en médecine à Batna (algérie), Rouen (France) et Sousse (Tunisie).

The objective of this study was to evaluate the use of the Internet by students in three francophone Faculties of Medicine, in Batna (Algeria), Rouen (France) and Sousse (Tunisia), and to identify and assess students' research skills in seeking educational resources. In 2008, a cross-sectional study was conducted in the three faculties. An anonymous self-administered questionnaire gathered information on the students' IT equipment, the interest and relevance of the Internet in the curriculum of medical studies, and information on the last three research efforts for educational resources done using the Internet. In Batna, 300 students were enrolled, 182 in Rouen and 87 in Sousse. Nearly 80% of students used the Internet to research educational resources. Students in Batna and Sousse more frequently reported a lack of appropriate or sufficient training for Internet use than students in Rouen. In total, 1288 Internet searches were analyzed. For an individual research effort on the Internet, the average time was 61,9 minutes (standard deviation [SD] = 65,9) in Batna, 26,3 minutes (SD = 30,2) in Rouen and 42,6 minutes (SD = 51, 0) Sousse (p 10-4). Less than one in two students considered their research successful. It is important to provide advice and guidance to students on how to use and interpret the multiple types and sources of medical information of varying quality that are found on the Internet. It is the responsibility of teachers to fulfill this role and help to facilitate the navigation of this new source of information.

Clonidine 1 microg/kg is a safe and effective adjuvant to plain bupivacaine in spinal anesthesia in adolescents.

BACKGROUND: Spinal anesthesia is increasingly used in adolescents. However, the anesthesia provided by bupivacaine alone may be too short for the planned surgery. The addition of clonidine 2 microg/kg to bupivacaine provides a prolonged anesthetic action but may be associated with hypotension. In the present study, we investigated the efficacy and safety of intrathecal clonidine 1 mug/kg in adjunction to bupivacaine in spinal anesthesia in adolescents. METHODS: Eighty-three adolescents, 51 males, aged 10-15 yr, scheduled for orthopedic surgery were enrolled in this placebo-controlled, randomized study. Patients were given spinal anesthesia either with plain 0.5% isobaric bupivacaine 0.2-0.4 mg/kg or bupivacaine with clonidine 1 microg/kg. The duration of sensory block was the primary outcome measure. RESULTS: Clonidine prolonged the duration of both the sensory and motor block. The time to regression of sensory block by two dermatomes was 136 (mean) (sd, 56) min in the adolescents with clonidine versus 107 min (sd, 42) in the controls (95% CI for diff: 5-53 min, P = 0.02). The time to full recovery of motor block was 251 min (sd, 79) in the adolescents with clonidine versus 181 min (sd, 59) in the controls (95% CI: 39-103 min, P = 0.001). Time to the first dose of rescue analgesia was longer in the adolescents with clonidine, 461 min (sd, 147) versus 330 min (sd, 138) in the controls (95% CI: 53-207 min, P = 0.01). There was no difference in the frequency of hypotension or bradycardia between the groups. CONCLUSION: In adolescents, clonidine 1 microg/kg prolonged the duration of sensory block achieved with bupivacaine by 30 min and postoperative analgesia by 120 min without severe adverse events.

A ketamine-propofol admixture does not reduce the pain on injection compared with a lidocaine-propofol admixture.

BACKGROUND: Propofol injection pain is a well-known problem in pediatric anesthesia. Premixture of lidocaine with propofol although effective does not abolish injection pain in all children. Promising results have been reported with pretreatment of the vein with ketamine. The purpose of this prospective, double-blind randomized, clinical trial with active control was to evaluate the efficacy of premixing propofol with ketamine in the prevention of injection pain in children. METHODS: After ethics committee and parental approval and children's assent, 116 children, aged 1-12 years, were randomly allocated to receive an IV induction dose of admixture of racemic ketamine 0.5 mg x ml(-1) (ketamine group) or lidocaine 1 mg x ml(-1) in propofol 10 mg x ml(-1) (lidocaine group). The outcome measures were signs and symptoms of injection pain (primary outcome: the incidence of injection pain), hemodynamic and respiratory parameters, and adverse effects during anesthesia induction (secondary outcomes). RESULTS: Patients' characteristics were similar in the two groups. Fewer children (13/58) in the lidocaine group than in the ketamine group (26/58) (mean difference 23%, 95% CI for difference 6-40%, P = 0.018) developed pain on injection of propofol. There were no differences in hemodynamic parameters between the two groups. One child in the lidocaine group developed laryngospasm, but no other adverse events were recorded. CONCLUSIONS: Injection pain was twice as common with ketamine-propofol admixture than with lidocaine-propofol admixture.

Clonidine administered as adjuvant for bupivacaine in ilioinguinal-iliohypogastric nerve block does not prolong postoperative analgesia.

BACKGROUND: Coadministration of clonidine with local anesthetics is associated with improvement of the quality of peripheral nerve block and significant prolongation of postoperative analgesia. Better analgesia has been reported with clonidine in ilioinguinal nerve block compared with caudal use. The object of this study was to determine whether adding of 1 microg.kg(-1) clonidine to bupivacaine 0.25% in ilioinguinal-iliohypogastric nerve block prolongs postoperative analgesia in children. METHODS: Ninety-eight children ASA I-II aged between 1 and 12 years, scheduled for elective outpatient herniorrhaphy or orchidopexy were randomly allocated to receive an ilioinguinal-iliohypogastric nerve block either with 0.3 ml.kg(-1) bupivacaine 0.25% plus 1 microg.kg(-1) clonidine or only bupivacaine. Postoperative analgesic needs, time to the first analgesic supplementation and sedation score were assessed in hospital for 6 h postoperatively and at home by telephone call. RESULTS: Demographic data were similar in both groups. There was no statistical difference in the rate of rescue analgesia between the two groups during the first six postoperative hours (20.4% group clonidine vs 30.6% group no clonidine) (P = 0.17). A slight decrease in systolic blood pressure during surgery was reported in the clonidine group. There was no difference in the scores of sedation between the two groups. At home, 10 patients in the clonidine group and nine patients in the nonclonidine group received analgesic medication. There was no difference between the two groups regarding the number of patients receiving analgesic rescue during the first 24 h (log rank = 0.39). Parental satisfaction was high in both groups. CONCLUSIONS: Our study failed to demonstrate any advantage in addition of 1 microg.kg(-1) clonidine to 0.25% bupivacaine for ilioinguinal-iliohypogastric nerve block compared with bupivacaine 0.25% alone.