Aspirin and other nonsteroidal antiinflammatory drugs inhibit prostaglandin synthesis and tumor growth in many experimental systems, but it is unclear which of these tumor models are relevant to humans. We have reported reduced risk of fatal colon cancer among persons who used aspirin in a large prospective study. This analysis examines other fatal cancers in relation to aspirin among 635,031 adults in that study who provided information in 1982 on the frequency and duration of their aspirin use and did not report cancer. Death rates were measured through 1988. Death rates decreased with more frequent aspirin use for cancers of the esophagus, stomach, colon, and rectum but not generally for other cancers. For each digestive tract cancer, death rates were approximately 40% lower among persons who used aspirin 16 times/month or more for at least 1 year compared to those who used no aspirin. The trend of decreasing risk with more frequent aspirin use was strongest among persons who had used aspirin for 10 years or more; it remained statistically significant, except for esophageal cancer, in multivariate analyses that adjusted for other known risk factors. Biases such as early detection or aspirin avoidance among cases do not appear to explain the results. Our data suggest that regular, prolonged use of aspirin may reduce the risk of fatal cancer of the esophagus, stomach, colon, and rectum. Future epidemiological and basic research should examine all digestive tract cancers in considering the chemopreventive or therapeutic potential of nonsteroidal antiinflammatory drugs.

https://cancerres.aacrjournals.org/content/canres/53/6/1322.full.pdf

Aspirin Use and Risk of Fatal Cancer

Omega-3 fatty acids as cancer chemopreventive agents.

Multistage carcinogenesis in mouse skin

Nutritional and medical importance of gamma-linolenic acid

Conjugated linoleic acid (CLA) is a chemoprotective fatty acid that inhibits mammary, colon, forestomach, and skin carcinogenesis in experimental animals. We hypothesize that the ubiquitous chemoprotective actions of dietary CLA in extrahepatic tissues are dependent upon its role in modulating fatty acid composition and metabolism in liver, the major organ for lipid metabolism. This study begins to evaluate the role of CLA in lipid metabolism by determining the modulation of fatty acid composition by CLA. Female SENCAR mice were fed semipurified diets containing 0.0% (Diet A), 0.5% (Diet B), 1.0% (Diet C), or 1.5% (Diet D) CLA (by weight) for six weeks. Mice fed Diets B, C, and D exhibited lower body weights and elevated amounts of extractable total lipid in livers compared with mice fed diets without CLA (Diet A). Analyses of the fatty acid composition of liver by gas chromatography revealed that dietary CLA was incorporated into neutral and phospholipids at the expense of linoleate in Diets B, C, and D; oleate increased and arachidonate decreased in neutral lipids of CLA diet groups. In addition, increasing dietary CLA was associated with reduced linoleate in hepatic phospholipids. In an in vitro assay, CLA was desaturated to an unidentified 18:3 product to a similar extent as linoleate conversion to gamma-linolenate (9.88, and 13.63%, respectively). These data suggest that CLA may affect metabolic interconversion of fatty acids in liver that may ultimately result in modified fatty acid composition and arachidonate-derived eicosanoid production in extrahepatic tissues. In addition to determining how dietary CLA modulates eicosanoid synthesis, further work is needed to identify enzymatic products that may result from desaturation of CLA.

Conjugated linoleic acid modulates hepatic lipid composition in mice.

The phylogenetic diversity of the bacterial and archaeal community in the water and sediments of three large lakes of the Wadi An Natrun was investigated using 16S rRNA clone libraries. The bacterial community was diverse: 769 clones formed 345 operational taxonomic units (OTUs) defined at 99% 16S rRNA sequence identity. The bacterial community in both the water and sediments of the lakes was dominated by clones affiliated with the low G + C Gram-type-positive group, α-proteobacteria, and Bacteroidetes, (11–39, 11–30, and 10–37% of OTUs observed, respectively), patterns that have been observed in previously described alkaline, athalassohaline systems. However, a relatively high proportion of Firmicutess-related clones in the water of the lakes and α-proteobacteria in the sediments was observed. The bacterial community composition of the water and sediment of the same lake and of different lakes was significantly different (p < 0.05). Operational taxonomic units related to the γ-proteobacteria were more abundant in the sediment of Lake Fazda, whereas the sediment of Lake UmRisha was dominated by members of the δ-proteobacteria. The proportion of γ-proteobacterial and Bacteroidetes-affiliated OTUs were predominant in the water of Lake UmRisha and differed significantly from other lake waters (chi-squared analysis, p ≤ 0.01). The more oxygenated and dilute nature of Lake Hamra was reflected in its microbial community composition, with the abundance of Bacillales sequences in the water, the absence of Halanaerobiales, Clostridiales, and Archaea in the water, and the presence of representatives of more phyla such as the Actinobacteria, Spirochaetes, and Verrucomicrobia. The archaeal community composition appeared less diverse: 589 clones resulted in 198 OTUs defined at 99% 16S rRNA sequence identity, and all sequences fell into the phylum Euryarchaeota. Phylogenetic analysis showed that many of the sequences were distantly related (83–90% 16S rRNA sequence identity) to cultured and uncultured archaea, with many clones forming clusters that branched deeply within the Euryarchaeota. Forty-two and 53% of the bacterial and archaeal clones had less than 90% 16S rRNA sequence identity to previously described sequences. This indicates that the water and sediments of the Wadi An Natrun harbor a unique and novel prokaryotic diversity that is different from what has been described among other alkaline, athalassohaline lakes.

Novel and Unexpected Prokaryotic Diversity in Water and Sediments of the Alkaline, Hypersaline Lakes of the Wadi An Natrun, Egypt

Effects of acute exposure to the radiofrequency fields of cellular phones on plasma lipid peroxide and antioxidase activities in human erythrocytes.

Terrestrial actinomycetes are noteworthy producers of a multitude of antibiotics, however the marine representatives are much less studied in this regard In this study, 90 actinomycetes were isolated from 11 different species of marine sponges that had been collected from offshore Ras Mohamed (Egypt) and from Rovinj (Croatia) Phylogenetic characterization of the isolates based on 16S rRNA gene sequencing supported their assignment to 18 different actinomycete genera representing seven different suborders Fourteen putatively novel species were identified based on sequence similarity values below 982% to other strains in the NCBI database A putative new genus related to Rubrobacter was isolated on M1 agar that had been amended with sponge extract, thus highlighting the need for innovative cultivation protocols Testing for anti-infective activities was performed against clinically relevant, Gram-positive (Enterococcus faecalis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria, fungi (Candida albicans) and human parasites (Leishmania major, Trypanosoma brucei) Bioactivities against these pathogens were documented for 10 actinomycete isolates These results show a high diversity of actinomycetes associated with marine sponges as well as highlight their potential to produce anti-infective agents

/pdf/isolation-phylogenetic-analysis-and-anti-infective-activity-2qhna7q4m9.pdf

Isolation, Phylogenetic Analysis and Anti-infective Activity Screening of Marine Sponge-Associated Actinomycetes

Virgin female Sprague-Dawley rats (50 days of age) were administered a single intragastric 10-mg dose of 7,12-dimethylbenz( a )anthracene (DMBA). Twenty-one days later they were placed on diets containing either 20% corn oil (CO), 15% menhaden oil plus 5% corn oil (MO + CO0, 20% CO plus 0.5% w/w of the irreversible ornithine decarboxylase inhibitor, d,l-2-difluoromethylornithine (CO + DFMO), 20% CO plus 0.004% w/w of the cyclooxygenase inhibitor indomethacin (CO + INDO), 20% CO + 0.004% INDO + 0.5% DFMO (CO + INDO + DFMO), or 15% MO + 5% CO + 0.5% DFMO (MO + CO + DFMO). The incidence of DMBA-induced mammary tumors was significantly reduced in rats fed diets containing DFMO but not in rats fed the diet containing indomethacin. Incidences of mammary tumors at 16 weeks post-DMBA were 86% in rats fed the CO diet, 83% in rats ingesting the diet containing CO + INDO, 28% in rats fed CO + DFMO, 32% in rats fed diet containing CO + INDO + DFMO, 59% in rats fed the MO + CO diet, and 24% in rats fed the MO + CO + DFMO diet. The average number of tumors and tumor burden per tumor-bearing rat were reduced and tumor latency was increased in all rats fed diets containing DFMO. Body weight gain, but not food intake, of rats fed the 20% fat + 0.5% DFMO diets was significantly less than in rats fed the 20% fat diets. Prostaglandin E and leukotriene (LTB4) syntheses, ODC activity and mammary tumorigenesis were significantly inhibited by feeding the diet containing menhaden oil or by adding 0.5% DFMO to any of the high fat diets. Feeding a 20% CO diet containing 0.004% INDO significantly reduced prostaglandin synthesis and ODC activity and increased LTB4 synthesis of mammary tumors but did not inhibit mammary tumorigenesis. This study suggests that the 5-lipoxygenase product LTB4 may be involved in mammary tumor production. Whereas a decrease in LTB4 appears to be associated with a decrease in tumorigenesis, an increase (as seen in the indomethacin group) was not associated with any change in the tumorigenic response.

/pdf/effects-of-d-l-2-difluoromethylornithine-and-indomethacin-on-3ivbisjbq9.pdf

Effects of D,L-2-difluoromethylornithine and indomethacin on mammary tumor promotion in rats fed high n-3 and/or n-6 fat diets.

Glutathione S-transferase (GST) protects cells against oxidative stress. We evaluated the effect of genetic polymorphisms of the GST gene family on the risk of developing type-2 diabetes mellitus and on glycemic control. We also investigated the effects of smoking combined with these polymorphisms on type-2 diabetes mellitus risk. We enrolled 100 type-2 diabetes mellitus patients and 100 healthy controls matched for age, gender and origin, from the Sinai area of Egypt. Fasting serum glucose, HbA(1c) and lipid profiles were determined. Two polymorphisms were identified by multiplex PCR within the GST genes: GSTM1 and GSTT1. The proportion of the GSTT1- and GSTM1-null genotypes was significantly greater in diabetic patients when compared to controls. Patients carrying both null polymorphisms had a 3.17-fold increased risk of having type-2 diabetes mellitus compared to those with normal genotypes of these two genes (P = 0.009). Additionally, patients with the GSTT1-null genotype had higher levels of triglycerides and very low-density lipoprotein cholesterol compared to those with the GSTT1-present genotype. On the other hand, patients with the GSTM1- null genotype had significantly higher levels of HbA(1c) and significantly higher diastolic blood pressure compared to those with the GSTM1- present genotype. The interaction between these genotypes and smoking status was not significant. These results give evidence that the GSTT1- and GSTM1-null genotypes, alone or combined, are associated with increased risk of type-2 diabetes mellitus, regardless of smoking status. Only the GSTM1-null genotype had an effect on glycemic control.

/pdf/influence-of-glutathione-s-transferase-polymorphisms-on-type-1yu0f3lm3l.pdf

Soad H. Abou-El-Ela

Papers

Novel and Unexpected Prokaryotic Diversity in Water and Sediments of the Alkaline, Hypersaline Lakes of the Wadi An Natrun, Egypt

Effects of acute exposure to the radiofrequency fields of cellular phones on plasma lipid peroxide and antioxidase activities in human erythrocytes.

Isolation, Phylogenetic Analysis and Anti-infective Activity Screening of Marine Sponge-Associated Actinomycetes

Effects of D,L-2-difluoromethylornithine and indomethacin on mammary tumor promotion in rats fed high n-3 and/or n-6 fat diets.

Influence of glutathione S-transferase polymorphisms on type-2 diabetes mellitus risk.