Ultrastructural Criteria That Prove the Similarities between Amphibian and Human Tumors

Self Cite

Liver tumors were induced in the toads, Bufo regularis, in 16 out of 50 cases by the administration of 0.2 mg DMBA/toad, 3 times/week for 12 weeks. Light and electron microscopic photographs demonstrate that these hepatocytes of DMBAtreated toads showed criteria of malignancy. In contrast, toads treated with DMBA at the same dose level and 0.005 percent w/w indomethacin/toad, 3 times/week for 12 weeks showed a lower incidence of liver tumors, 8 out of 50 cases. The biochemical analysis showed that the activity of G6PD, LDH, acid phosphatase and alkaline phosphatase enzymes were decreased in animals treated with DMBA and indornethacin in comparison with toads treated with DMBA alone. It is concluded that indomethacin has an inhibitory effect on hepatocarcinogenesis in toads.

Section: Discussionsupporting

confidence: 93%

Anti-inflammatory Drug (Indomethacin) and its Effect on Liver Tumor Induced by DMBA

Abdelmeguid¹,

Sadek²,

Sorour³

et al. 1999

Self Cite

“…However, type 2 nuclear pockets seems to arise by invagination of the inner nuclear envelope, producing a meandering cleft which sequestrates nuclear material ultimately producing a type 2 pocket. On the other hand, Abdelmeguid et al (1997) observed the two types of nuclear pockets in amphibian tumor. Ultrastructural changes on the surface and within the cytoplasm of mucosa cells including epithelial mucous cells were observed, indicating disturbed metabolism.…”

Section: Discussionmentioning

confidence: 99%

Criteria Characterizing Tumor Cells Observed in the Helicobacter Pylori- Associated-Gastric Epithelial Cells and Predicting Tumorgenesis

Abdelmeguid¹

1999

Helicobacter pylori infection appears to be the most important cause of gastritis, gastric and duodenal ulcer. Biopsy specimens of gastric mucosa of patients with chronic gastritis proven by bacteriological test and endoscopy assessed the presence of organisms in lumen of numerous glands. Light and electron micrographs revealed curved organism, quite close to superficially damaged epithelial cells. Although no direct contact could be detected between the organisms and the epithelial cells yet they influenced their outlook. Changes on the microvillus surface, as well as within the epithelial cells were noticed. The most important of which are the frequent presence of pale-nuclei, type 1 nuclear pocket and nuclear inclusion in the nuclei and pusity of organelle in their cytoplasm. The observation indicated disturbed metabolism and predicting early transformation of normal cells to tumor cells.

“…On the other hand, some studies on the effect of retinoid on carcinogenesis have given apparently contradictory results. In tumor promotion studies, retinoid both inhibit (Hill and Grubbs, 1992) and enhance (Hasegawa et al, 1988) the induction of tumors in toads and human were reported (Abdelmeguid et al, 1997). The present study therefore was undertaken to determine whether acrylamide have any carcinogenic effects on liver of the Egyptian toad, Bufo regularis and to clarify the role of B-carotene on the liver in the experimental toads, previously treated with acrylamide.…”

Section: Introductionmentioning

confidence: 97%

B-carotene Lock the Effect of Acrylamide on Liver in the Egyptian Toad

Sadek¹,

Abou-Gabal²

1999

Several studies on the harmful effects of chemical pollutants have had an increasing influence on public cancer policy. It has been shown that acrylamide, which is widely used in the synthesis of variety of polymers, induced liver tumor in the Egyptian toad (9 cases out of 50 cases). The liver tumor was diagnosed as hepatocellular carcinoma. In contrast toads treated with acrylamide and B-carotene (3 hr. prior to the carcinogen) completely blocked the hepatocarcinogenesis in toads. However B-carotene was less effective when administered 3 hr, after the carcinogen (acrylamide) in 7 out of 50 cases. It is concluded that B-carotene has an inhibitory effect on hepatocarcinogenesis in toads during initiation.