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Paulo Kassab

Publications and source records attributed to Paulo Kassab.

7 recordsLinked to original sources
PubMed2003

Protective effect of ascorbic acid in experimental gastric cancer: reduction of oxidative stress.

AIM: Oxidative stress participates in the cell carcinogenesis by inducing DNA mutations. Our aim was to assess whether ascorbic acid, an antioxidant, could have a role in preventing ROS (Reactive Oxygen Species) generation in experimental gastric carcinoma in a rat model. METHODS: Experimental gastric cancer was induced in twelve Wistar male rats (weighting 250-350 g) by profound duodeno-gastric reflux throught split gastrojenunostomy. The rats were allocated to the following groups: Group I (n=6) was the control; Group II (n=6) which was mantained with daily intake of tape water with Vitamin C (30 mg/Kg). After 6 or 12 months, samples of gastric tumor or non tumor mucosa were taken from the anastomosis of both groups. Oxidative stress was measured by superoxide quantification through lucigenin-amplified chemiluminescence base and by staining with Nitrobluetetrazolium. The histopathologic confirmation of adenocarcinoma was made by eosin-hemathoxilin method. RESULTS: The intestinal type of gastric adenocarcinoma was microscopically identified in all animals of group I whereas only 3 rats of group II showed an adenocarcinoma without macroscopic evidence of them. The cancers were located in the anastomosis in all cases. Basal luminescence from tumor gastric tissue generated 38.4+/-6.8 count per minute/mg/X10(6) (mean+/-SD) and 14.9+/-4.0 count per minute/mg/X10(6), respectively, in group I and II animals (P<0.05). The Nitrobluetetrazolium method showed intense staining in tumor tissues but not in non neoplasic mucosa. CONCLUSION: Experimental gastric tumors seem to produce more reactive oxygen species than non neoplasic gastric tissue. The reduction of oxidative stress and gastric tumor incidence in rats were induced by the intake of ascorbic acid. Therefore, it may have a role in the prevention of gastric carcinoma.

Animals↗
PubMedDate not supplied

[Simulation of D1 lymphadenectomy in patients submitted to D2 lymphadenectomy. Prospective study of 57 patients with gastric adenocarcinoma].

BACKGROUND: To simulate a D1 lymphadenectomy in 57 patients who had already been submitted to D2 lymphadenectomy, and analyze stage migration using the Japanese Gastric Cancer Association (JGCA) staging system. METHODS: All patients underwent a D2 lymphadenectomy between August 1997 and November 2001. At the end of surgery, the surgeon himself separated all lymph node stations. The parameters analyzed were: sex, age, lymph node invasion and number of dissected nodes. All patients were re-staged based on the new data, in order to evaluate the stage migration according to the JGCA staging system. RESULTS: The advanced tumors corresponded to 80.70% and the early ones to 19.30%. In 43.90% there were positive nodes at N1 and N2 levels. The mean number of dissected lymph nodes was 28.63 in each patient. In IA, IB and II tumors, there were no changes in the stage after simulation of D1 lymphadenectomy. In ten IIIA tumors, three migrated to stage II and IB; in 21 tumors staged as IIIB, a migration was observed in 18; all stage IV tumors migrated to IIIB after the D1 simulation. CONCLUSION: a) D2 lymphadenectomy is important for the correct staging of gastric cancer; b) simulation of D1 lymphadenectomy changed the stage of advanced tumors, particularly in stages IIIA, IIIB, and IV; c) D2 lymphadenectomy avoided residual lymph node disease in almost half of the patients operated.

Adenocarcinoma↗