Effect of Helicobacter pylori infection on IL-8, IL-1 and COX-2 expression in patients with chronic gastritis and gastric cancer

Objective. Helicobacter pylori infection is related to gastric cancer development, and chronic inflammation is presumed to be the main cause. The aim of the present study was to evaluate the influence of H. pylori cagA, vacA, iceA, and babA genotypes on COX-2, IL-1, and IL-8 expression. Material and methods. of the 217 patients included in the study, 26 were uninfected, 127 had chronic gastritis and were H. pylori-positive, and 64 had gastric cancer. Bacterial genotypes were evaluated by polymerase chain reaction (PCR), and the expression values were determined by quantitative real-time PCR and immunohistochemistry. Results. An association was found between the infection with cagA, vacA s1m1 strains and gastric cancer development. Regarding the 3' region of the cagA gene, we also found an association between the infection with cagA EPIYA-ABCCC strains and clinical outcome. Higher levels of IL-8, IL-1, and COX-2 were detected in gastric mucosa from infected patients with chronic gastritis, and they were also associated with the infection by cagA, vacA s1m1 strains. The IL-8 and IL-1 levels decrease significantly from chronic gastritis to gastric cancer, while the relative expression remained unaltered when COX-2 expression was analyzed among patients with gastritis and cancer. Conclusions. Since inflammatory response to H. pylori infection plays an important role in cellular proliferation and gastric mucosal damage, the up-regulation of IL-1, IL-8, and COX-2 in patients with chronic gastritis has an important clinical implication in gastric carcinogenesis.

Antigenotoxicity and antimutagenicity of lycopene in HepG2 cell line evaluated by the comet assay and micronucleus test

Epidemiological studies have provided evidence that high consumption of tomatoes effectively reduces the risk of reactive oxygen species (ROS)-mediated diseases such as cancer. Tomatoes are rich sources of lycopene, a potent singlet oxygen-quenching carotenoid. In addition to its antioxidant properties, lycopene shows an array of biological effects including antimutagenic and anticarcinogenic activities. In the present study, the chemopreventive action of lycopene was examined on DNA damage and clastogenic or aneugenic effects of H2O2 and n-nitrosodiethylamine (DEN) in the metabolically competent human hepatoma cell line (HepG2 cells). Lycopene at concentrations of 10. 25, and 50 mu M, was tested under three protocols: before, simultaneously, and after treatment with the mutagen, using the comet and micronucleus assays. Lycopene significantly reduced the genotoxicity and mutagenicity of H2O2 in all of the conditions tested. For DEN, significant reductions of primary DNA damage (comet assay) were detected when the carotenoid (all of the doses) was added in the cell culture medium before or simultaneously with the mutagen. In the micronucleus test, the protective effect of lycopene was observed only when added prior to DEN treatment. In conclusion, our results suggest that lycopene is a suitable agent for preventing chemically-induced DNA and chromosome damage. (C) 2007 Elsevier Ltd. All rights reserved.

Effects of Helicobacter pylori Infection on the Expressions of Bax and Bcl-2 in Patients with Chronic Gastritis and Gastric Cancer

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Paracoccidioidomycosis in a Dog: Case Report of Generalized Lymphadenomegaly

Paracoccidioidomycosis (PCM) is a severe systemic mycosis, endemic in Latin America and highly prevalent in Brazil, where it ranks eighth as a mortality cause among infectious and parasitic diseases in humans. The disease in animals has been little explored. It is observed that armadillos can harbor the fungus at high frequencies, although the active disease has not been well documented in this wild mammal. Dogs are susceptible to experimental infection, and the naturally acquired PCM-disease was reported only recently in a dog from Brazil. The present work reports the second case of naturally acquired PCM in a 6-year-old female dog that presented emaciation, lymphadenomegaly, and hepatosplenomegaly. Biochemical and pulmonary radiographic evaluation did not reveal any abnormalities. PCM was diagnosed by clinical findings, culturing, immunohistochemistry, and histopathology of popliteal lymph node. The fungus was recovered from popliteal lymph node, and the molecular analysis showed respective sequencing similarities of 99 and 100% for 803 nucleotides of the Gp43 gene and 592 nucleotides from the ITS-5.8S region of Paracoccidioides brasiliensis. Immunohistochemistry revealed severe lymphadenitis and presented numerous yeasts, which reacted against the gp43 antibody. Histopathology revealed a severe granulomatous lymphadenitis associated with numerous single or multiple budding yeasts. After diagnosis, the dog was successfully treated with itraconazol for 2 years. Veterinarians should be aware of the importance of considering PCM for differential diagnosis, especially in dogs from PCM-endemic areas, whose monophagocytic system involvement is evident.

No mutations found in exon 2 of gene p16CDKN2A during rat tongue carcinogenesis induced by 4-nitroquinoline-1-oxide

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Does toxoplasmosis cause DNA damage? An evaluation in isogenic mice under normal diet or dietary restriction

Toxoplasmosis is an anthropozoonotic widespread disease, caused by the coccidian protozoan parasite Toxoplasma gondii. Since there are no data regarding the genotoxicity of the parasite in vivo, this study was designed to evaluate the genotoxic potential of the toxoplasmosis on isogenic mice with normal diet or under dietary restriction and submitted to a treatment with sulfonamide (375 mug/kg per day). DNA damage was assessed in peripheral blood, liver and brain cells using the comet assay (tail moment). The results for leucocytes showed increases in the mean tail moment in mice under dietary restriction; in infected mice under normal diet; in infected, sulfonamide-treated mice under normal diet; in infected mice under dietary restriction and in infected sulfonamide-treated mice under dietary restriction. In liver and brain cells, no statistically significant difference was observed for the tail moment. These results indicated that dietary restriction and T. gondii were able to induce DNA damage in peripheral blood cells, as detected by the comet assay. (C) 2004 Elsevier B.V. All rights reserved.

Caracterização morfodinâmica do estuário do Rio Açu, Macau/RN

Estuaries are coastal environments ephemeral life in geological time, derived from the drowning of the shoreline as a function of elevation relative sea level. Such parallel systems is characterized by having two sources of sediment, the river and the sea. The study area comprises the Acu River estuary, located on the northern coast of Rio Grande do Norte State, in a region of intense economic activity, mainly focused on the exploration of oil onshore and offshore, likely to accidental spills. In the oil sector are developed for salt production, shrimp farming, agriculture, fisheries and tourism, which by interacting with sensitive ecosystems, such as estuaries, may alter the natural conditions, thus making it an area susceptible to contamination is essential in understanding the morphodynamic variables that occur in this environment to obtain an environmental license. Information about the submarine relief the estuaries are of great importance for the planning of the activity of environmental monitoring, development and coastal systems, among others, allowing an easy management of risk areas, and assist in the creation of thematic maps of the main aspects of landscape. Morphodynamic studies were performed in this estuary in different seasonal periods in 2009 to observe and quantify morphological changes that have occurred and relate these to the hydrodynamic forcing from the river and its interaction with the tides. Thus, efforts in this area is possible to know the bottom morphology through records of good quality equipment acquired by high resolution geophysical (side-scan sonar and profiler current by doppler effect). The combination of these data enabled the identification of different forms of bed for the winter and summer that were framed in a lower flow regime and later may have been destroyed or modified forms of generating fund scheme than the number according Froude, with different characteristics due mainly to the variation of the depth and type of sedimentary material they are made, and other hydrodynamic parameters. Thus, these features background regions are printed in the channel, sandy banks and muddy plains that border the entire area

Levels of DNA damage in blood leukocyte samples from non-diabetic and diabetic female rats and their fetuses exposed to air or cigarette smoke

dThe objective of the present study was to evaluate DNA damage level in blood leukocytes from diabetic and non-diabetic female Wistar rats exposed to air or to cigarette smoke, and to correlate the findings with levels of DNA damage detected in blood leukocyte samples from their fetuses. A total of 20 rats were distributed into four experimental groups: non-diabetic (control; G1) and diabetic exposed to filtered air (G2): non-diabetic (G3) and diabetic (G4) exposed to cigarette smoke. Rats placed into whole-body exposure chambers were exposed for 30 min to filtered air (control) or to tobacco smoke generated from 10 cigarettes, twice a day, for 2 months. Diabetes was induced by a pancreatic beta-cytotoxic agent, streptozotocin (40 mg/kg b.w.). At day 21 of pregnancy, each rat was anesthetized and humanely killed to obtain maternal and fetal blood samples for genotoxicity analysis using the alkaline comet assay. G2, G3 and G4 dams presented higher DNA damage values in tail moment and tail length as compared to G1 group. There was a significant positive correlation between DNA damage levels in blood leukocyte samples from G2 and G3 groups (tail moment); G3 and G4 groups (tail length) and G3 group (tail intensity) and their fetuses. Thus, this study showed the association of severe diabetes and tobacco cigarette smoke exposure did not exacerbate levels of maternal and fetal DNA damages related with only diabetes or cigarette smoke exposure. Based on the results obtained and taking into account other published data, maternal diabetes requires rigid clinical control and public health and education campaigns should be increased to encourage individuals, especially pregnant women, to stop smoking. (C) 2008 Elsevier B.V. All rights reserved.

Clinical features of tic-related obsessive-compulsive disorder: results from a large multicenter study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Agaricus blazei (Himematsutake) does not alter the development of rat diethylnitrosamine-initiated hepatic preneoplastic foci

The modifying potential of crude extracts of the mushroom Agaricus blazei Murrill (Himematsutake) on the development and growth of glutathione S-transferase placental form (GST-P)-positive liver foci (liver preneoplastic lesion) was investigated in adult male Wistar rats. Six groups of animals were used. Groups 2 to 5 were given a single i.p. injection of 200 mg/kg b.w. of diethylnitrosamine (DEN) and groups 1 and 6 were treated with saline at the beginning of the experiment. After 2 weeks, animals of groups 3 to 6 were orally treated with three dose levels of aqueous extracts of the mushroom A. blazei (1.2, 5.6, 11.5, and 11.5 mg/ml of dry weight of solids) for 6 weeks. All animals were subjected to two-thirds partial hepatectomy at week 3 and sacrificed at week 8. Two hours before sacrifice, ten animals of each group were administered a single i.p injection of 100 mg/kg of bromodeoxyuridine (BrdU). Apoptotic bodies and BrdU-positive hepatocyte nuclei were quantified in liver sections stained for hematoxylin and eosin (H&E) (eosinophilic foci) and simultaneously stained for GST-P expression (GST-P-positive foci), respectively. The 6-week treatment with A. blazei did not alter the development (number and size) of GST-P-positive foci and did not affect the growth kinetics of liver normal parenchyma or foci in DEN-initiated animals. Our results indicate that the treatment with aqueous extracts of the mushroom A. blazei during the post-initiation stage of rat liver carcinogenesis does not exert any protective effect against the development of GST-P-positive foci induced by DEN. (Cancer Sci 2003; 94: 188-192).

DNA damage in patients infected by Helicobacter pylori

Helicobacter pylori (H. pylori) is considered to predispose carriers to gastric cancer but its role on gastric carcinogenesis is still unknown. The aim of this study was to investigate DNA damage by the comet assay in gastric epithelial cells from antrum and corpus in H. pylori-infected patients with gastritis of different degrees. H. pylori status, gastric histology, and DNA damage were studied in 62 H. pylori-infected and 18 non-infected patients, all of them non-smokers, nonalcoholics, and non-drug users. DNA damage was significantly higher in H. pylori-infected patients presenting gastritis than in non-infected patients with normal mucosa. A direct correlation between the levels of DNA damage and the intensity of gastritis was observed in H. pylori-infected patients. Association between DNA damage and age was also found. The levels of DNA damage were significantly higher in patients older than 50 years than in younger patients with the same degree of gastritis. Our results indicate that H. pylori infection is associated with DNA damage in gastric epithelial cells, which could be a biomarker of risk for gastric cancer in humans.

Biocompatibility in vitro tests of mineral trioxide aggregate and regular and white Portland cements

Mineral trioxide aggregate (MTA) and Portland cement are being used in dentistry as root end-filling materials. However, biocompatibility data concerning genotoxicity and cytotoxicity are needed for complete risk assessment of these compounds. In the present study, genotoxic and cytotoxic effects of MTA and Portland cements were evaluated in vitro using the alkaline single cell gel (comet) assay and trypan blue exclusion test, respectively, on mouse lymphoma cells. The results demonstrated that the single cell gel (comet) assay failed to detect DNA damage after a treatment of cells by MTA and Portland cements for concentrations up to 1000 mu g/ml. Similarly, results showed that none of the compounds tested were cytotoxic. Taken together, these results seem to indicate that MTA and Portland cements are not genotoxins and do not induce cellular death.

Evaluation of genetic damage in human peripheral lymphocytes exposed to mineral trioxide aggregate and Portland cements

Mineral trioxide aggregate (MTA) and Portland cement are being used in dentistry as root-end-filling material for periapical surgery and for the sealing of communications between the root canal system and the surrounding tissues. However, genotoxicity tests for complete risk assessment of these compounds have not been conducted up to now. In the present study, the genotoxic effects of MTA and Portland cements were evaluated in peripheral lymphocytes from 10 volunteers by the alkaline single cell gel (comet) assay. The results pointed out that the single cell gel (comet) assay failed to detect the presence of DNA damage after a treatment of peripheral lymphocytes by MTA and Portland cements for concentrations up to 1000 mu g mL(-1). In summary, our results indicate that exposure to MTA or Portland cements may not be a factor that increases the level of DNA lesions in human peripheral lymphocytes as detected by single cell gel (comet) assay.

Viable human buccal mucosa cells do not yield typical nucleoids: Impacts on the single-cell gel electrophoresis/comet assay

Buccal mucosa (BM) cells have been used in human biomonitoring studies for detecting DNA adducts and chromosomal damage in an epithelial cell population. In the present study, we have investigated if human BM cells are suitable for use in the single-cell gel electrophoresis (SCGE)/Comet assay as an approach for estimating the exposure of epithelial cells to DNA-damaging agents. Our results indicate that only a few cells from BM cell samples yield comets that can be analyzed by current methods, and that the yield of cells with comets is independent of the percentage of viable BM cells in the sample. Data generated after enzymatic enrichment of viable cells and immunomagnetic separation of epithelial cells suggest that most of the BM cells that do form comets are probably leukocytes. Moreover, by reevaluating specific cells after running the Comet assay, we found that viable epithelial BM cells give rise to atypical comets that are not included in the analysis. Comparing DNA migration patterns between small groups of smokers and nonsmokers indicated that long-term smoking had no effect on the subpopulation of cells that yield typical comets. Our results indicate that the SCGE assay, as it is commonly performed, may not be useful for genotoxicity monitoring in human epithelial BM cells.