Evaluation of smoking genotoxicity in Turkish young adults

BACKGROUND:

For the past few decades, it has been widely known in developed countries that tobacco is dangerous, but it is still insufficiently realized how big these dangers really are.

AIMS:

To determine and evaluate micronuclei (MN) frequencies of young smokers and nonsmokers in three different tissues (peripheric blood lymphoctes, buccal mucosa, and exfoliative urothelial cells) at the same time.

MATERIALS AND METHODS:

MN assay was performed on buccal mucosa, urothelial cells, and peripheric blood lymphocyte samples obtained from 15 healthy male smokers (>5 pack-years) and 15 healthy male nonsmoker controls who had not been exposed to any known genotoxic agent.

STATISTICAL ANALYSIS USED:

The statistical differences between smoker and nonsmoker groups were calculated by using student t test. The differences between smoker-group tissues were compared by ANOVA.

RESULTS:

It was found that MN frequency (mean value ± standard deviation) in oral mucosa cells from smokers and controls were 1.20 ± 0.22% and 0.26 ± 0.10%; in urothelial exfoliative cells, 1.29 ± 0.28% and 0.12 ± 0.08%; in peripheric blood lymphocytes, 1.53 ± 0.23% and 0.38 ± 0.12%, respectively. The mean MN frequencies in buccal mucosa, urothelial exfoliative cells, and peripheric blood lymphocytes were significantly higher in smokers than in those of controls (P<0.05). All tissues were affected from smoking, but the most destructive effect was seen in urothelial cells of smokers (P<0.05).

CONCLUSIONS:

Our data showed that cigarette smoke is a DNA damage causitive agent on exfoliative buccal mucosa and urothelial cells and peripheric blood lymphocytes of young smokers, but it has most destructive effect on urothelial cells.     

Detection of Adenoviruses and Rotaviruses in Drinking Water Sources Used In Rural Areas of Benin,West Africa

Diseases associated with viruses also found in environmental samples cause major health problems in developing countries. Little is known about the frequency and pattern of viral contamination of drinking water sources in these resource-poor settings. We established a method to analyze 10 liters of water from drinking water sources in a rural area of Benin for the presence of adenoviruses and rotaviruses. Overall, 541 samples from 287 drinking water sources were tested. A total of 12.9% of the sources were positive for adenoviruses and 2.1% of the sources were positive for rotaviruses at least once. Due to the temporary nature of viral contamination in drinking water sources, the probability of virus detection increased with the number of samples taken at one test site over time. No seasonal pattern for viral contaminations was found after samples obtained during the dry and wet seasons were compared. Overall, 3 of 15 surface water samples (20%) and 35 of 247 wells (14.2%) but also 2 of 25 pumps (8%) tested positive for adenoviruses or rotaviruses. The presence of latrines within a radius of 50 m in the vicinity of pumps or wells was identified as being a risk factor for virus detection. In summary, viral contamination was correlated with the presence of latrines in the vicinity of drinking water sources, indicating the importance of appropriate decision support systems in these socioeconomic prospering regions.Although access to safe drinking water is considered a human right, many people suffer from inadequate water supply. Especially in developing countries, improper water quality causes major public health problems affecting mortality rates in highly susceptible people (small children and immunocompromised patients) as well as economic income problems due to disease-related nonproductive time. Only 37.4% of households have access to piped water sources in Benin, West Africa, and in rural areas, even fewer have access (3). Many diseases like diarrhea, gastroenteritis, keratoconjunctivitis, respiratory infections, and hepatitis are associated with viruses, often found in environmental samples like groundwater, surface water, sewage, costal water, shellfish, and tap water (5, 6, 10, 13, 23, 38). Virus concentrations in environmental samples are low both due to the inability to replicate without a host cell and because of continuous degradation and dilution effects. On the other hand and in contrast to most bacterial infections, even small amounts of viruses (as few as 10 PCR-detectable units) are sufficient to establish an infection in the new host (24). Bacterial indicators seem to be inappropriate for analyzing viral contamination, since viruses are more resistant to environmental conditions (2) and spread over a longer distance than bacteria (9). Therefore, viruses are often found without any bacterial indicator for fecal contamination (2, 6). In North America, 15 to 30% of all gastrointestinal diseases were suspected of being related to water (30), whereas worldwide, over 88% of diarrheal diseases are waterborne or water related (18).Routine screening of environmental samples for viral contamination is controversially being discussed at the moment. Furthermore, no standard procedure for the detection of viruses in environmental samples currently exists. In numerous studies, virus concentration from water was achieved by filtration using electropositive filters (1MDS) (12, 15, 25, 26, 33). Further methods using ultrafiltration, glass wool filters (7, 22), or immunomagnetic separation (16, 28) were used to detect small amounts of viruses independently of matrix effects. However, the U.S. Environmental Protection Agency listed adenovirus as one of nine microorganisms on the contamination candidate list for drinking water as a potential indicator virus due to an outstanding resistance to UV disinfection. The 51 presently recognized adenovirus serotypes are responsible for a great variety of human diseases like diarrhea, keratoconjunctivitis, and respiratory infections. However, severe diarrhea, especially in small children and immunocompromised patients, is often caused by rotaviruses. The fatal outcome of infant diarrhea substantially contributes to the high mortality rate of children under the age of 5 years in developing countries (8). In Benin, the probability of dying per 1,000 live births under 5 years of age (under-5 mortality rate) was 152 in 2004, and 17.1% of these deaths were caused by diarrheal diseases (37). To address the frequency and pattern of viral contamination in drinking water sources in rural areas of West Africa, we analyzed water samples during the dry and wet seasons in Benin for contamination with adenoviruses as indicators and rotaviruses as important pathogens in developing countries.     

Efficient,reproducible <Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated transformation of sorghum using heat treatment of immature embryos

A number of parameters related to Agrobacterium-mediated infection were tested to optimize transformation frequencies of sorghum (Sorghum bicolor L.). A plasmid with a selectable marker, phosphomannose isomerase, and an sgfp reporter gene was used. First, storing immature spikes at 4°C before use decreased frequency of GFP-expressing calli, for example, in sorghum variety P898012 from 22.5% at 0 day to 6.4% at 5 days. Next, heating immature embryos (IEs) at various temperatures for 3 min prior to Agrobacterium infection increased frequencies of GFP-expressing calli, of mannose-selected calli and of transformed calli. The optimal 43°C heat treatment increased transformation frequencies from 2.6% with no heat to 7.6%. Using different heating times at 43°C prior to infection showed 3 min was optimal. Centrifuging IEs with no heat or heating at various temperatures decreased frequencies of all tissue responses; however, both heat and centrifugation increased de-differentiation of tissue. If IEs were cooled at 25°C versus on ice after heating and prior to infection, numbers with GFP-expressing cells increased from 34.2 to 49.1%. The most optimal treatment, 43°C for 3 min, cooling at 25°C and no centrifugation, yielded 49.1% GFP-expressing calli and 8.3% stable transformation frequency. Transformation frequencies greater than 7% were routinely observed using similar treatments over 5 months of testing. This reproducible frequency, calculated as numbers of independent IEs producing regenerable transgenic tissues, confirmed by PCR, western and DNA hybridization analysis, divided by total numbers of IEs infected, is several-fold higher than published frequencies.     

The effects of indomethacin, NDGA, allopurinol and superoxide dismutase on prostaglandin E2 and leukotriene C4 levels after mesenteric ischemia-reperfusion injury

In this study, the changes of arachidonic acid metabolites after an ischemia-reperfusion (I/R) period are investigated. The cyclooxygenase and lipoxygenase metabolites were found to be significantly increased after a 45 min period of ischemia followed by 5 min of reperfusion. Prostaglandin E₂ (PGE₂)- and leukotriene C₄ (LTC₄)-like activities did not change in the ischemic period, but they both increased after reperfusion. A cyclooxygenase inhibitor indomethacin and lipoxygenase inhibitor nordehydroguaretic acid (NDGA) decreased PGE₂- and LTC₄-like activities, respectively, while allopurinol and superoxide dismutase (SOD) decreased both activities.According to our results, it can be assumed that free oxygen radicals are responsible for the elevation of PGE₂- and LTC₄-like activities and both of these arachidonic acid metabolites and free oxygen radicals are the main necrotizing agents in ischemia-reperfusion induced damage.     

The relationship between nitric oxide and leptin in the lung of rat with streptozotocin-induced diabetes

Lung structural changes and immunoreactivity of endothelial (eNOS)- and inducible nitric oxide synthase (iNOS) were investigated by light microscopy in lungs of treated and untreated diabetic rats. Diabetes was induced by a single intraperitoneal (i.p.) injection of 65 mg kg(-1) streptozotocin (STZ) in Wistar albino male rats. Diabetic rats received daily i.p. doses of dexamethasone (2 mg kg(-1)), leptin (0.5 microg kg(-1)) and intramuscular insulin (20 U kg(-1)) or a combination of these drugs for 1 week starting 4 weeks after the STZ injections. After treatment, the blood levels of glucose, leptin, insulin and nitrate/nitrite (NO(3) (-)/NO(2) (-)) were measured. Dilatation of alveoli and alveolar ducts, partial alveolar wall thickening and increased eNOS- and iNOS characterized the diabetic rat lungs. High blood glucose and nitrate/nitrite levels as well as low insulin and leptin levels were also present. Treatment with insulin, dexamethasone and a combination of these drugs resulted in improvement of the structural and immunohistochemical abnormalities. The most effective treatment was insulin therapy. Leptin administration resulted in increased relative amounts of extracellular material, which led to noticeable respiratory efficiency in the diabetic rat lungs. All treatments except leptin lowered blood glucose levels. The combination of insulin and dexamethasone increased blood leptin and insulin, while the remaining diabetic rats had blood with low leptin and insulin concentrations. These results suggest that therapy with insulin plus dexamethasone but not therapy with leptin is beneficial for diabetics.     

Biotechnology Applications for Sugar Beet

Sugar beet (Beta vulgaris L.) is an important industrial crop, being one of only two plant sources from which sucrose (i.e., sugar) can be economically produced. Despite its relatively short period of cultivation (ca. 200 years), its yield and quality parameters have been significantly improved by conventional breeding methods. However, during the last two decades or so, advanced in vitro culture and genetic transformation technologies have been incorporated with classical breeding programs, the main aim being the production of herbicide-and salt-tolerant, disease- and pest-resistant cultivars. Among the many applications of in vitro culture techniques, sugar beet has benefited the most from haploid plant production, protoplast culture, and somaclonal variation and in vitro cell selection. Several genetic transformation technologies have been developed, such as Agrobacterium-meditated, PEG-mediated, particle bombardment, electroporation, sonication and somatic hybridization, the first two being the most successful. Development of herbicide- and salt-tolerant, virus-, pest/nematode-, fungus/Cercospora- and insect-resistant sugar beet has been demonstrated. However, only herbicide-tolerant varieties have been approved for commercialization but not yet available in the marketplace; rhizomania-resistant varieties are being evaluated in field trials. Transgenic plants that convert sucrose into fructan, a polymer of fructose, were also developed. Initial attempts to increase sucrose yields produced promising results, but it still requires additional work. Despite marked progress in improving regeneration and transformation of sugar beet, genotype dependence and low regeneration and transformation frequencies are still serious restrictions for routine application of in vitro culture and, more importantly, transformation technologies. Selected food safety and environmental impact, as well as regulatory and public acceptance issues relating to transgenic sugar beet are also discussed.     

Effect of black cumin (Nigella sativa) on cadmium-induced oxidative stress in the blood of rats

The protective effect of black cumin (Nigella sativa=NS) on cadmium-induced oxidative stress was studied in rats. The rats were randomly divided into three experimental groups: A (conrol), B (Cd treated), and C (Cd+NS treated), each containing 10 animals. The Cd-treated and Cd+NS-treated groups were injected subcutaneously daily with CdCl₂ dissolved in isotonic NaCl in the amount of 2 mL/kg for 30 d, resulting in a dosage of 0.49 mg Cd/kg/d. The control group was injected with only isotonic NaCl (2 mL/kg/d) throughout the experiment (for 30 d). Three days prior to induction of CdCl₂, the Cd+NS-treated group received a daily intraperitoneal injection of 0.2 mL/kg NS until the end of the study. Cd treatment increased significantly the malondialdehyde levels in plasma and erythrocyte (p<0.01 and p<0.05, respectively) and also increased significantly the antioxidant levels (superoxide dismutase, glutathione peroxidase, and catalase) (p<0.05) compared to the control group. Cd+NS treatment decreased significantly the elevated malondialdehyde levels in plasma and erythrocyte (p<0.01 and p<0.05, respectively) and also reduced significantly the enhanced antioxidant levels (p<0.05). Cd treatment increased significantly the activity of iron levels (p<0.05) in the plasma compared to the control group. Cd+NS treatment decreased the activity of iron levels (p<0.05) in the plasma compared to the Cd-treated group. In the control group with no treatment, histology of erythrocytes was normal. In the Cd-treated group, there were remarkable membrane destruction and hemolytic changes in erythrocytes. In the Cd+NS treated group, these changes were less than in the Cd-treated group. Our results show that N. sativa exerts a protective effect against cadmium toxicity.     

Associations among plasma selenium,zinc, copper,and iron concentrations and immunoregulatory cytokine levels in patients with cutaneous leishmaniasis

Plasma essential trace elements, selenium, copper, zinc, and iron concentrations and the levels of immunoregulatory cytokines, interleukin-1β (IL-1β), interleukin-2 receptor (IL-2r), IL-6, IL-8, and tumor necrosis factor-α (TNF-α) were evaluated in patients with cutaneous leishmaniasis (CL) to investigate a possible role of these cytokines on selenium, zinc, copper, and iron homeostasis in CL patients. Plasma albumin levels were measured as an index of nutritional status. Plasma selenium, zinc, and iron concentrations, and IL-2r levels were significantly lower, and copper concentrations and IL-1β, IL-8, IL-6 and TNF-α levels were significantly higher in patients with CL than those of healthy controls. There was no significant difference in plasma albumin levels between two groups. There were positive important correlations between plasma selenium and IL-2r, copper and IL-6, and copper and IL-1β, and negative correlations between selenium and IL-8, iron and TNF-α, and zinc and IL-1β contents in patients with CL. Our results showed that plasma trace element contents change in patients with CL. These changes may not be a result of a specific deficiency from dietary inadequacies or imbalances, but, probably, a result of a part of the defense strategies of an organism that is regulated by immunoregulatory cytokines.