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Tunis, Tunisia

Rouissi K.,Laboratory of Genetics | Ouerhani S.,Laboratory of Genetics | Hamrita B.,Laboratory of Genetics | Bougatef K.,Tunis el Manar University | And 6 more authors.
Pathology and Oncology Research | Year: 2011

Cancer epidemiology has undergone marked development since the nineteen-fifties. One of the most spectacular and specific contributions was the demonstration of the massive effect of smoking and genetic polymorphisms on the occurrence of bladder cancer. The tobacco carcinogens are metabolized by various xenobiotic metabolizing enzymes, such as the super-families of Nacetyltransferases (NAT) and glutathione S-transferases (GST). DNA repair is essential to an individual's ability to respond to damage caused by tobacco carcinogens. Alterations in DNA repair genes may affect cancer risk by influencing individual susceptibility to this environmental exposure. Polymorphisms in NAT2, GST and DNA repair genes alter the ability of these enzymes to metabolize carcinogens or to repair alterations caused by this process. We have conducted a case-control study to assess the role of smoking, slow NAT2 variants, GSTM1 and GSTT1 null, and XPC, XPD, XPG nucleotide excision-repair (NER) genotypes in bladder cancer development in North Tunisia. Taken alone, each gene unless NAT2 did not appear to be a factor affecting bladder cancer susceptibility. For the NAT2 slow acetylator genotypes, the NAT2*5/*7 diplotype was found to have a 7- fold increased risk to develop bladder cancer (OR=7.14;95% CI: 1.30-51.41). However, in tobacco consumers, we have shown that Null GSTM1, Wild GSTT1, Slow NAT2, XPC (CC) and XPG (CC) are genetic risk factors for the disease. When combined together in susceptible individuals compared to protected individuals these risk factors give an elevated OR (OR=61). So, we have shown a strong cumulative effect of tobacco and different combinations of studied genetic risk factors which lead to a great susceptibility to bladder cancer. © Arányi Lajos Foundation 2011.


Boubaker K.,Charles Nicole Hospital
Saudi journal of kidney diseases and transplantation : an official publication of the Saudi Center for Organ Transplantation, Saudi Arabia | Year: 2013

Euphorbia paralias is known in traditional medicine as an anti-inflammatory agent, a purgative and for its local anesthetic property. To the best our knowledge, renal toxicity of this substance has not been previously reported. In this paper, we report the case of a 29-year-old male who developed renal damage following ingestion of Euphorbia paralias. He had been on follow-up for nephrotic syndrome since 1986, although irregularly, with several relapses but each responding well to steroid therapy. A kidney biopsy had not been performed earlier due to refusal by the patient. He was off steroids since April 2008 because the patient developed osteoporosis. He was admitted with general malaise and oliguria to our department in May 2009, following repeated vomiting and watery diarrhea for three days. On examination, he was edematous but had normal vital signs except for a pulse rate of 120/min. Hemoglobin was only 5.5 g/dL but with normal white cell and platelet counts. Blood biochemistry showed evidence of advanced renal failure with a serum creatinine level of 1835 μmol/L and urea at 44.6 mmol/L, sodium of 132 μmol/L and potassium at 4.3 mmol/L. He had features of nephrotic syndrome with severe hypoproteinamia and 24-h urinary protein of 10.45 g. Ultrasonography revealed enlarged kidneys with a reduced echogenecity of the medulla and the papillae. Subsequently, after hemodialysis with blood transfusion, a kidney biopsy was performed that showed focal segmental glomerulosclerosis associated with an acute tubular injury. On intensive interrogation, the patient gave a history of ingesting boiled Euphorbia paralias as a native treatment for edema, ten days prior to the onset of the current illness. A diagnosis of acute renal failure (ARF) resulting from the possible nephrotoxic effect of Euphorbia paralias poisoning was made. He was treated with intermittent hemodialysis and corticosteroids. Serum creatinine values improved after 48 days. At six months following the intoxication, serum creatinine of the patient was 240 μmol/L. In cases of unexplained ARF, a toxic mechanism should always be considered and acute renal failure caused by Euphorbia paralias should be included as a cause if renal toxicity is suspected in those places where it is being used as a native medicine.


Kouidhi S.,University of Manar | Rouissi K.,University of Manar | Khedhiri S.,University of Prince Edward Island | Ouerhani S.,Pasteur Institute | And 2 more authors.
Asian Pacific Journal of Cancer Prevention | Year: 2011

Epidemiological studies have investigated that functional polymorphisms in the methylene- tetrahydrofolate reductase (MTHFR) gene may play an essential role in bladder carcinogenesis, but the numerous published studies have reported inconclusive results. The objective of the current study was to conduct an updated analysis in order to investigate the association between polymorphisms in the MTHFR gene and risk of bladder cancer. We searched the Pubmed database for all articles published up to March 31, 2011 that addressed bladder cancer and polymorphisms and variants or mutations of MTHFR for analysis using statistical software. Results for two polymorphisms (C677T and A1298C) in 27 case-control were studies from 15 articles indicated individuals carrying the 677T allele (TC or TT+TC) to have a reduction to a 29% or 21% compared to the wild genotype (CC) in mixed populations (OR: 0.71, 95%CI: 0.55-0.93 or OR: 0.79, 95%CI: 0.64-0.97, respectively) and it is shown that there is significant positive associations between A1298C polymorphism and bladder cancer in Africans (OR: 1.24, 95%CI: 1.02-1.52 for C vs.A; OR: 1.35, 95%CI: 1.10-1.66 for CA vs. AA; OR: 1.29, 95%CI: 1.08-1.55 for CC+CA vs. AA). However, no significant relationship was found in two polymorphisms in the stratified analysis by smoking status. Interestingly, individuals carrying the 677T allele (TT+TC) demonstrated a higher percentage of invasive than superficial cases (OR: 1.38, 95%CI: 1.13-1.69). The results from the current update analysis suggest that C677T and A1298C polymorphisms in the MTHFR gene are associated with bladder cancer risk and prognosis. Further evaluation based on more studies with larger groups of patients are now required.


Houissa F.,Charles Nicole Hospital
La Tunisie médicale | Year: 2011

Colonoscopy is the standard investigation for colonic disease, but clinicians often are reluctant to refer elderly patients for colonoscopy because of a perception of higher risk and a high rate of incomplete examinations. To evaluate feasibility and tolerance of this investigation in elderly and to review the most frequent indications of colonoscopy in these patients. A pilot retrospective study including 901 patients from January 2005 to December 2009; divided into two groups. Group (I) included patients 75 years old and more, group (II) included patients 45 years old or less. All those patients underwent colonoscopy at the gastroenterology department of Charles Nicole hospital. The 1st group included 231 patients, and the 2nd group included 670 one. A past history of colorectal cancer was more frequent in the group I (33.3% versus 9.90%; p<0.05) however history of chronic inflammatory bowel disease was more frequent in group II (0 versus 40.6%; p<0.05). The main indication of colonoscopy was constipation in group II (6.1% versus 27%; p<0.05) and chronic diarrhoea in group I (42.9% versus 16.4%; p<0.05). Bowel preparation was poor in 30.4% cases of the group I and 12.9% of group II (p<0.05). The tolerance was similar in the two groups. The incomplete colonoscopy rate was higher in the group I (38.3% versus 23.4%; p<0.05). The most frequent cause of colonoscopy interruption was the poor preparation in group I and the bad tolerance in group II. Diverticular disease, polyps and colorectal cancers prevailed in group I, whereas inflammatory bowel disease was current in group II. In elderly patients, colonoscopy is safe, well tolerated and offers a good diagnostic yield. Its non completion was essentially due to the poor preparation. Sedation did not seem essential. The optimisation of results of colonoscopy requires an improvement of quality preparation.


Khedhiri S.,University of Prince Edward Island | Stambouli N.,University of Tunis | Ouerhani S.,Institute Pasteur | Rouissi K.,University of Tunis | And 3 more authors.
Journal of Cancer Research and Clinical Oncology | Year: 2010

Cigarette smoking is the predominant risk factor for bladder cancer in males and females. The tobacco carcinogens are metabolized by various xenobiotic metabolizing enzymes such as N-acetyltransferases (NAT) and glutathione S-transferases (GST). Polymorphisms in NAT and GST genes alter the ability of these enzymes to metabolize carcinogens. In this paper, we conduct a statistical analysis based on logistic regressions to assess the impact of smoking and metabolizing enzyme genotypes on the risk to develop bladder cancer using a case-control study from Tunisia. We also use the generalized ordered logistic model to investigate whether these factors do have an impact on the progression of bladder tumors. © 2010 Springer-Verlag.

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