Papers by Khaled Trabelsi
Nanoscale Research Letters, 2014
This work deals with the deposition of Cr-doped TiO 2 thin films on porous silicon (PS) prepared ... more This work deals with the deposition of Cr-doped TiO 2 thin films on porous silicon (PS) prepared from electrochemical anodization of multicrystalline (mc-Si) Si wafers. The effect of Cr doping on the properties of the TiO 2 -Cr/PS/Si samples has been investigated by means of X-ray diffraction (XRD), atomic force microcopy (AFM), photoluminescence, lifetime, and laser beam-induced current (LBIC) measurements. The photocatalytic activity is carried out on TiO 2 -Cr/PS/Si samples. It was found that the TiO 2 -Cr/PS/mc-Si type structure degrades an organic pollutant (amido black) under ultraviolet (UV) light. A noticeable degradation of the pollutant is obtained for a Cr doping of 2 at. %. This result is discussed in light of LBIC and photoluminescence measurements.
American Journal of Analytical Chemistry, 2014
La Tunisie médicale, 2002
Pancreatic involvement in sarcoïdosis is exceptional. We report a case of pancreatic sarcoïdosis ... more Pancreatic involvement in sarcoïdosis is exceptional. We report a case of pancreatic sarcoïdosis diagnosed during the etiologic work-up done for a pancreatic mass associated to a polyadenopathy. Under corticotherapy evolution is favorable with regression of the pancreatic lesions.
La Tunisie médicale, 2002
Pulmonary arterial hypertension PAH is one of the rare expressions of cirrhosis and defined by a ... more Pulmonary arterial hypertension PAH is one of the rare expressions of cirrhosis and defined by a pressure more than 30 mmHg. We report our results in a Tunisian Seria results: 21 cirrhotic patients (19M/12F) with a median age of 60 years (22 to 85) explored by cardiac echographic with measures of PAH. We observe an elevated PAH in 31% of cases. Conclusion elevated PAH is relatively frequent during the evolution of cirrhosis. This symptom needs to be systematically explored in patients proposed for liver graft because increased PAH is a contraindication for liver transplantation.
Chronobiology international, Jan 9, 2015
The aim of this study was to investigate the effect of an Olympic-Weightlifting-session followed ... more The aim of this study was to investigate the effect of an Olympic-Weightlifting-session followed by 48-h recovery period on the oxidative and antioxidant parameters' diurnal variation. Nine weightlifters (21 ± 0.5 years) performed, in randomized order, three Olympic-Weightlifting-sessions at 08 h:00, 14 h:00 and 18 h:00. Blood samples were collected: at rest and 3 min and 48 h after each session. C-reactive protein (CRP), rate of lipid peroxidation and antioxidant activities were assessed. At rest, analysis of variance showed a significant time of day (TOD) effect (p < 0.05) for uric acid, catalase and glutathione peroxidase with higher values at 14 h:00 and 18 h:00 compared with 08 h:00. However, no significant TOD effect for malondialdehyde, total bilirubin and CRP was observed. Given the profound changes (p < 0.001) in the post-training session values, these diurnal variations have been altered immediately and even 48 h after the training sessions. Despite the significa...
La Tunisie médicale, 2008
To compare the tocolytic action and the side effects of nicardipine to those of salbutamol in pat... more To compare the tocolytic action and the side effects of nicardipine to those of salbutamol in patients presenting premature labor in order to propose nicardipine as a promising alternative to salbutamol in the treatment of premature labor. forty eight patients admitted for premature labor were included in this prospective randomized study comparing nicardipine and salbutamol, administered with intra venous drip. The nicardipine group included 25 patients and the salbutamol group included 23 patients. the epidemiologic characteristics of the 2 groups are similar. No significant difference between the 2 groups was noted in the average time of disappearance of the uterine contractions. In nicardipine group, the pregnancy was prolonged more than 48 hours in 87.5% of the cases against 85.8% in salbutamol group (P: NS). Adverse effects linked to tocolysis were recorded. In nicardipine group, 8% of the patients presented an intolerance of the molecule, against 47% of salbutamol group, the ...
International journal of sport nutrition and exercise metabolism, 2012
The aim of this study was to evaluate the effects of a hypertrophic training program during Ramad... more The aim of this study was to evaluate the effects of a hypertrophic training program during Ramadan on body composition and selected metabolic markers in trained bodybuilders. Sixteen male recreational bodybuilders (9 Ramadan fasters and 7 nonfasters) participated in the study. All visited the laboratory 2 d before the start of Ramadan (Bef-R) and on the 29th day of Ramadan (End-R). In the morning of each session, subjects underwent anthropometric measurement, completed a dietary questionnaire, and provided fasting blood and urine samples. Body mass and body-mass index in nonfasters increased by 2.4% (p = .05 and p = .04, respectively) from Bef-R to End-R but remained unchanged in fasters over the period of the investigation. Fasters experienced an increase in the following parameters from Bef-R to End-R: urine specific gravity (1%, p = .022) and serum concentrations of urea (5%, p = .008), creatinine (5%, p = .007), uric acid (17%, p < .001), sodium (2%, p = .019), potassium (6%...
Asian journal of sports medicine, 2011
To evaluate the effect of Ramadan fasting on body water status markers of rugby players at basal ... more To evaluate the effect of Ramadan fasting on body water status markers of rugby players at basal condition and following a simulation of rugby sevens match. TWELVE RECREATIONAL RUGBY SEVENS PLAYERS PLAYED THREE MATCHES: one day before Ramadan (before Ramadan), at the end of the first week of Ramadan (Beg-R) and at the end of Ramadan (End-R). Before and immediately after each match, body weight was determined and blood samples were taken for the measurement of body water status markers. Total body water was measured with an impedancemeter only before matches. At rest, an increase in hematocrit (+4.4%, P=0.03), hemoglobin (+3.4%, P=0.01) and plasma osmolarity (+2.8%, P<0.001) was noticed at End-R compared to before Ramadan. Total body water measured before Ramadan did not differ significantly from that of Ramadan. After the match, values of hematocrit and plasma osmolarity increased significantly at End-R (+1.4%, P=0.02; +3.1%, P<0.001 respectively) compared to before Ramadan. A...
Asian journal of sports medicine, 2011
The aim of this study was to assess the effects of Ramadan fasting on several biochemical and ant... more The aim of this study was to assess the effects of Ramadan fasting on several biochemical and anthropometric parameters in physically active men by comparing fasters and nonfasters before, during, and after Ramadan. Eighteen physically active men (10 fasters and 8 nonfasters) participated in this study. Subjects visited the laboratory for a total of four sessions on the following occasions: three days before Ramadan (Bef-R), the 15(th) day of Ramadan (Mid-R), the 29(th) day of Ramadan (End-R), and 21 days after Ramadan (Post-R). During each session, subjects underwent anthropometric measurements, completed a dietary questionnaire and provided a fasting blood sample. Body weight and body fat percentage decreased in fasters by 1.9% (P<0.001) and 6.2% (P=0.003), respectively, but increased in nonfasters by 2.2% (P<0.001) and 10.2% (P=0.001), respectively, from Bef-R to End-R. Fasters' hematocrit and hemoglobin increased by 5.3% (P<0.001) and 6.3% (P=0.01), respectively, fr...
International journal of sport nutrition and exercise metabolism, 2012
The aim of this study was to evaluate the effects of aerobic training in a fasted versus a fed st... more The aim of this study was to evaluate the effects of aerobic training in a fasted versus a fed state during Ramadan on body composition and metabolic parameters in physically active men. Nineteen men were allocated to 2 groups: 10 practicing aerobic training in a fasted state (FAST) and 9 training in an acutely fed state (FED) during Ramadan. All subjects visited the laboratory for a total of 4 sessions on the following occasions: 3 days before Ramadan (Bef-R), the 15th day of Ramadan; the 29th day of Ramadan (End-R), and 21 days after Ramadan. During each session, subjects underwent anthropometric measurement, completed a dietary questionnaire, and provided fasting blood and urine samples. Body weight decreased in FAST and FED by 1.9% (p<.001) and 2.6% (p=.046), respectively. Body fat percentage decreased only in FAST by 6.2% (p=.016). FAST experienced an increase in the following parameters from Bef-R to End-R: urine specific gravity (0.64%, p=.012), urea (8.7%, p<.001), cre...
Measles vaccination remains the most efficient way to control the spread of the virus. This work ... more Measles vaccination remains the most efficient way to control the spread of the virus. This work focuses on the production of a measles vaccine using stirred conditions as an advanced option for process scale up. Non-porous Cytodex 1 microcarriers were used to support MRC-5 cell growth in suspension cultures. Virus replication was first optimized in spinner flasks, and the effects of various operational parameters were investigated. Cell infection with AIK-C measles strain at an MOI (multiplicity of infection) of 0.005, without glucose regulation and in M199 medium, resulted in a virus titer of 10 6.25 TCID 50 (median tissue culture infective dose)/ml. To optimize the production process in a 7-l bioreactor, we carried out various perfused cultures using minimum essential medium (MEM)+5% FCS diluted with phosphate-buffered saline (PBS). We achieved a high cell density level (4.1× 10 6 cells/ml) with an efficient use of the medium when MEM+5% FCS diluted with PBS at 25% was used during the cell amplification step. Optimization of measles production in MRC-5 cells grown on Cytodex 1 beads in a 7l bioreactor showed that perfusion was the most efficient when compared to repeated-batch culture. Perfusion at a rate of 0.25 V (reactor volume)/day showed the highest specific productivity (1.6 IVP [infectious virus particle] cell −1 day −1 ). Testing of several stabilizers containing pharmaceutically improved components such as sugars, amino acids, and charged ions showed that the formulation composed of sucrose and MgCl 2 , led to the maintenance of the infectivity of the AIK-C measles virus strain to a significant level, when stored at +28°C, +4°C and −60°C.
Vaccine
IPT-AFM is a proprietary animal component free medium that was developed for rabies virus (strain... more IPT-AFM is a proprietary animal component free medium that was developed for rabies virus (strain LP 2061) production in Vero cells. In the present work, we demonstrated the versatility of this medium and its ability to sustain the growth of other cell lines and different virus strains. Here, three models were presented: Vero cells/rabies virus (strain LP 2061), MRC-5 cells/measles virus (strain AIK-C) and BHK-21 cells/rabies virus (strain PV-BHK21). The cell lines were first adapted to grow in IPT-AFM, by progressive reduction of the amount of serum in the culture medium. After their adaptation, BHK-21 cells grew in suspension by forming clumps, whereas MRC-5 cells remained adherent. Then, kinetics of cell growth were studied in agitated cultures for both cell lines. In addition, kinetics of virus replication were investigated.
Applied Microbiology and Biotechnology
Vero cells growth and rabies production in IPT-AF medium, a property animal-component-free medium... more Vero cells growth and rabies production in IPT-AF medium, a property animal-component-free medium are described in this work. Kinetics of cell growth and rabies virus (strain LP 2061) production were first conducted in spinner flasks. Over eight independent experiments, Vero cell growth in IPT-AF medium, on 2 g/l Cytodex 1 was consistent. An average Cd (cell division number) of 3.3+/-0.4 and a specific growth rate micro of 0.017+/-0.006 h(-1) were achieved. Such performances were comparable to those obtained in serum-containing medium (MEM+10% FCS). Rabies virus production on Vero cells in IPT-AF medium was also optimised in spinner flasks. The effects of multiplicity of infection (MOI), regulation of glucose level at 1 g/l and cell washing step, were investigated. The highest virus titer was achieved when the cells were infected at an MOI of 0.1; this level was equal to 10(7) FFU/ml. The step of medium exchange before cell infection can be omitted; nevertheless in this case glucose...
Subcultivation of Vero cells grown in a proprietary animal component-free medium named IPT-AFM, o... more Subcultivation of Vero cells grown in a proprietary animal component-free medium named IPT-AFM, on microcarriers, was studied. TrypLE Select, a non-animal-derived protease, was used as an alternative to trypsin for cell passaging. We first studied the effect of increasing concentrations of TrypLE Select toward cell growth and then studied the inactivation of the protease using either soybean trypsin inhibitor (STI) or the soy hydrolysate Hypep 1510, in sixwell plates. Data showed that cell growth was impaired by residual level of TrypLE Select; STI was identified as an efficient agent to neutralize this effect. To restore cell growth and inactivate TrypLE Select, STI should be added to the medium at least at 0.2 g L −1 . Cells were also grown in spinner flask on 2 g L −1 Cytodex1 in IPT-AFM. In these conditions, the cell detachment yield was equal to 78±8 %. Furthermore, cells exhibited a typical growth profile when using the dislodged cells to seed a new culture. A cell detachment yield of 70±19 % was also achieved when the cells were grown in a 2-L stirred bioreactor in IPT-AFM, on 3 g L −1 Cytodex1. This protocol can be of great interest to scale-up the process of Vero cells cultivation in IPT-AFM on Cytodex1 from one stirred bioreactor culture to another.
Vaccine
The efficiency of an inactivated tissue culture rabies vaccine produced on BHK-21 cells, accordin... more The efficiency of an inactivated tissue culture rabies vaccine produced on BHK-21 cells, according to an in-house developed process, was evaluated and compared to a commercial cell-tissue culture vaccine (Rabisin). Fifteen experimental dogs from local common breed were duly conditioned during a quarantine period, then vaccinated via the subcutaneous route with 1 ml of either the tissue culture vaccine developed in-house or the commercial vaccine Rabisin. The immune response of each dog was monitored for 162 days. Serum-neutralizing antibodies titers to rabies virus were determined by the rapid fluorescent focus inhibition test (RFFIT) which confirmed the strong response of dogs to both vaccines except one dog in the Rabisin group. The dogs were then challenged in the masseter muscle with a rabies street virus of canine origin. All vaccinated dogs except the single dog in the Rabisin group that failed to respond to the vaccine, survived the challenge. In contrast, 80% of animals in t...
Applied biochemistry and biotechnology
Subcultivation of Vero cells grown in a proprietary animal component-free medium named IPT-AFM, o... more Subcultivation of Vero cells grown in a proprietary animal component-free medium named IPT-AFM, on microcarriers, was studied. TrypLE Select, a non-animal-derived protease, was used as an alternative to trypsin for cell passaging. We first studied the effect of increasing concentrations of TrypLE Select toward cell growth and then studied the inactivation of the protease using either soybean trypsin inhibitor (STI) or the soy hydrolysate Hypep 1510, in six-well plates. Data showed that cell growth was impaired by residual level of TrypLE Select; STI was identified as an efficient agent to neutralize this effect. To restore cell growth and inactivate TrypLE Select, STI should be added to the medium at least at 0.2 g L(-1). Cells were also grown in spinner flask on 2 g L(-1) Cytodex1 in IPT-AFM. In these conditions, the cell detachment yield was equal to 78 ± 8 %. Furthermore, cells exhibited a typical growth profile when using the dislodged cells to seed a new culture. A cell detachm...
Journal of Biotechnology
To improve rabies vaccine production by Vero cells, we have developed a strategy based on high ce... more To improve rabies vaccine production by Vero cells, we have developed a strategy based on high cell density culture and optimization of virus yield. We have first optimized cell growth in spinner flask using a Taguchi's L8 experimental design. We analyzed the effects of the following factors: initial glucose and glutamine concentrations, Cytodex 1 concentration and the regulation of glucose level at 1 g l(-1). We have also investigated the effect of the following factor interactions: Cytodex 1 concentration/glutamine concentration, Cytodex 1 concentration/glucose concentration and glucose concentration/glutamine concentration. Statistical analysis of the collected data pointed to the initial glucose concentration, the regulation of glucose level at 1 g l(-1) and the interactions between Cytodex 1 concentration/initial glucose concentration and Cytodex 1 concentration/initial glutamine concentration as the parameters that affected cell growth. Using the optimal conditions determi...
Applied Microbiology and Biotechnology
Measles vaccination remains the most efficient way to control the spread of the virus. This work ... more Measles vaccination remains the most efficient way to control the spread of the virus. This work focuses on the production of a measles vaccine using stirred conditions as an advanced option for process scale up. Non-porous Cytodex 1 microcarriers were used to support MRC-5 cell growth in suspension cultures. Virus replication was first optimized in spinner flasks, and the effects of various operational parameters were investigated. Cell infection with AIK-C measles strain at an MOI (multiplicity of infection) of 0.005, without glucose regulation and in M199 medium, resulted in a virus titer of 10⁶·²⁵ TCID₅₀ (median tissue culture infective dose)/ml. To optimize the production process in a 7-l bioreactor, we carried out various perfused cultures using minimum essential medium (MEM) + 5% FCS diluted with phosphate-buffered saline (PBS). We achieved a high cell density level (4.1 × 10⁶ cells/ml) with an efficient use of the medium when MEM + 5% FCS diluted with PBS at 25% was used dur...
Biochemical Engineering Journal, 2014
Sheep pox virus initially adapted to replicate in primary lamb kidney cells was adapted to Vero c... more Sheep pox virus initially adapted to replicate in primary lamb kidney cells was adapted to Vero cells by serial passages in monolayer cultures. After nine passages the virus was able to correctly replicate in Vero cells, virus titer achieved was 10 5.875 TCID 50 (median tissue culture infective dose) ml −1 .
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Papers by Khaled Trabelsi