Lobna Ben Mahmoud

Risk factors for acute decompensation of chronic kidney disease in hospitalized patients in the nephrology department: a case-control study.

OBJECTIVE To investigate risk factors for acute kidney injury (AKI) in hospitalized patients with chronic kidney disease (CKD) a case-control study was conducted in the Nephrology Department of Hedi Chaker University Hospital in Sfax, Tunisia, for a 1-year period. METHODS All patients with baseline renal insufficiency hospitalized for AKI were considered as cases. They were compared with control patients with CKD. A conditional logistic regression model was used to identify independent risk factors for AKI in patients with CKD. RESULTS A total of 58 cases were compared with 114 control subjects. In multivariable models, baseline diabetes, cardiopathy disease, and exposure to non-steroidal anti-inflammatory drugs were independent risk factors for AKI in patients with CKD. However, exposure to calcium channel blockers (CCBs) was associated with decreased risk for AKI on CKD (OR = 0.4; CI 95%: 0.2 - 0.8, p = 0.007). CONCLUSIONS Patients with CKD may benefit from more aggressive cardiovascular screening to prevent episodes of acute kidney injury. More efforts should be made to prevent prescription drug abuse and to demonstrate the role of CCBs in renal protection in these patients.

Use of MTHFR C677T polymorphism and plasma pharmacokinetics to predict methotrexate toxicity in patients with acute lymphoblastic leukemia

BACKGROUND Methotrexate (MTX) is a key component of acute lymphoblastic leukemia (ALL) therapy, but it is associated with serious toxicities in a considerable number of patients. OBJECTIVES The aim of the current study was to determine which variables were associated with MTX toxicity in children, adolescents and young adults with ALL. MATERIAL AND METHODS In this prospective study, 35 patients with newly diagnosed ALL, treated according to the 58951 European Organization for Research and Treatment of Cancer - Childrens Leukemia Group (EORTC-CLG) protocol, were prospectively enrolled. Toxicity data was collected objectively after each high-dose methotrexate (HD-MTX) course. The risk factors of MTX toxicity were determined using multiple linear regression analysis, with age, gender, immunophenotype, risk group, plasma MTX levels, plasma homocysteine (HCY) levels, and MTHFR C677T included as independent variables. RESULTS Twenty-five (71.4%) patients experienced toxicity on at least 1 course of HD-MTX. In the univariate linear regression, the global toxicity score was associated with a significant rise in plasma HCY concentrations within 48 h after MTX administration (β = 0.4; R2 = 0.12; p = 0.02). In the multiple regression model, the global toxicity score was significantly associated with a higher MTX plasma levels at 48 h (β = 0.5; R2 = 0.38; p = 0.001) and CT 677 MTHFR genotype (β = 0.3; R2 = 0.38; p = 0.01). CONCLUSIONS Routine monitoring of plasma MTX concentrations is essential to detect patients at a high risk of MTX toxicity. MTHFR C677T genotyping may be useful for predicting MTX toxicity.

Oxidative Stress in Tunisian Patients With Acute Lymphoblastic Leukemia and Its Involvement in Leukemic Relapse

The aim of the present study was to evaluate in patients with acute lymphoblastic leukemia (ALL), the oxidative status and antioxidant defense and its involvement in the relapse of ALL. The plasmatic levels of malondialdehyde, advanced oxidation of protein products and reduced glutathione (GSH), and the plasmatic activities of catalase, superoxide dismutase (SOD), and glutathione peroxidase were determined in 34 patients who were newly diagnosed with ALL and compared with 92 healthy individuals. The plasmatic concentrations of malondialdehyde and advanced oxidation of protein products were higher in ALL patients than in controls and increased during chemotherapy. A decrease in glutathione peroxidase activity and an increase in catalase and SOD activities and GSH plasma levels were observed in ALL patients, as compared with sex-matched controls. Moreover, SOD activity and GSH levels were significantly correlated with the relapse of ALL patients. These data suggest the involvement of oxidative stress in acute lymphoid leukemias and leukemic relapse.

Optimization of therapeutic drug monitoring of vancomycin in patients with chronic hemodialysis .

PURPOSE To validate a simplified vancomycin monitoring algorithm in patients on chronic hemodialysis who required intravenous vancomycin for at least 3 weeks. MATERIALS AND METHODS In this prospective study, all hemodialysis patients who were admitted between April 1, 2013, and March 31, 2015, in our unit for suspected or confirmed methicillin-resistant Staphylococcus aureus infection that required vancomycin were enrolled. All patients were categorized into two groups. In group 1 (standard vancomycin dosing algorithm), the maintenance doses of vancomycin were adjusted according to the pre-hemodialysis vancomycin concentrations determined before each hemodialysis session. In group 2 (simplified vancomycin dosing algorithm), pre-dialysis vancomycin trough levels were taken before the 2nd and the 6th session of hemodialysis. Maintenance doses were adjusted according to the residual concentrations of vancomycin. RESULTS A total of 101 blood samples were collected, the average plasma concentration of vancomycin was 13.1 ± 3.8 µg/mL. 64 (63.4%) levels fell out of the therapeutic range. Seven (6.9%) of these exceeded the therapeutic range and 30 (29.7%) were lower. After the loading dose, the average plasma concentration was 11.2 ± 3.4 µg/mL. There were no statistically significant differences between the two groups with respect to the average plasma concentration of vancomycin and the proportion of vancomycin trough levels in the target range. CONCLUSION The vancomycin dosing algorithm using limited concentration monitoring for hemodialysis patients achieved drug concentrations comparable to those found with more frequent monitoring and resulted in significant cost savings.
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Polysaccharides extraction from Opuntia stricta and their protective effect against HepG2 cell death and hypolipidaemic effects on hyperlipidaemia rats induced by high-fat diet

Abstract The aim of this study was to analyse cytoprotective effect of polysaccharides compound from Opuntia stricta (O. stricta) cladode (POS) in vitro including its radical scavenging activities and protective effects against hypercholesterolaemia. Our results showed that glucose was the dominant monosaccharides (30.35%). Arabinose, pyranose, fructose, galactose, glucose, sorbitol, S-inositol, M-inositol, trehalose and saccharose found in this species. O. stricta polysaccharides did not cause any cytotoxic effect on HepG2 cells within the range of concentrations tested (0–400 μgml−1). Pre-treatment of HepG2 cells with POS (100 μgml−1) significantly (p < .05) protected against cytotoxicity induced by DPPH and ABTS radicals. The POS showed strong antioxidant potential in vitro. The results indicated also that POS significantly prevented hypercholesterolaemia-induced elevation of serum biomarkers and induced increase in serum lipid profile. Moreover, the hypercholesterolaemia characterised by elevated lipid peroxidation (MDA) and reduced antioxidant enzyme defences (SOD, CAT and GPx) was restored by POS treatment.