Photoprotective effects of some quinoxaline 1,4-dioxides in hairless mice

2-benzoyl-3-phenylquinoxaline 1,4-dioxide (BPQ) and other substituted quinoxaline 1,4-dioxides (QdO) were tested for their ability to inhibit the stimulations of ornithine decarboxylase (ODC) enzyme activity and DNA synthesis, two biochemical markers linked to skin tumour promotion by ultraviolet B (UVB) radiation. Topical application of BPQ on the dorsal skin of hairless mice was found to inhibit in a dose-dependent manner UVB-induced ODC activity and DNA synthesis. When applied 20 min before UVB radiation, a dose of 17 mg BPQ applied in 0.4 ml of vehicle inhibited UVB-induced ODC activity and DNA synthesis by 95% and 85%, respectively. This inhibitory effect is dependent on the time of administration of BPQ relative to UVB radiation, with a generally greater inhibition observed when this compound is applied before rather than after UVB treatment. The inhibitory abilities of the other QdO on the ODC and DNA responses induced by UVB radiation greatly varied and appear to be dependent on the structure of the compounds and their metabolic activation in the skin following irradiation. The remarkable effectiveness of BPQ against the ODC and DNA markers of UVB promotion is also observed following multiple applications of this agent. These results suggest that QdO, in particular BPQ and certain derivatives of it, may be useful in protecting the skin against UVB-induced skin damage.     

The Effects of Pre-Treatment and Post-Treatment of Thymol against tert-Butyl Hydroperoxide (t-BHP) Cytotoxicity in MCF-7 Cell Line and Fibroblast Derived Foreskin

Background:Some recent studies have reported anti-tumor activity for Thymol, but the findings are inconsistent. This study aimed to investigate and compare Thymol''s effects on MCF-7 cancer cells and fibroblasts while treated with tert-Butyl hydroperoxide (t-BHP).Methods:In the pre-treatment, MCF-7 and fibroblast cells were treated with various Thymol concentrations and incubated for 24 h. Then, t-BHP was added to a final concentration of 50 μM, and the cells were incubated for one h. In the post-treatment, cells were incubated first with 50 μM t-BHP for one h and then treated with Thymol. Cell viability was tested by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Thymol''s antioxidant capacity was measured by DPPH and FRAP assays, and lipid peroxidation levels were determined by the TBARS method.Results:The thymol effects were dose-dependent, and despite their antioxidant properties, at concentrations of 100 µg/ml or more, increased t-BHP toxicity and reduced cancer cell viability. MTT assay result showed that pre-treatment and post-treatment with Thymol for 24 hours effectively reduced MCF-7 and fibroblast cell viability compared with the untreated control group. Both pre- and post-treatment of Thymol, normal fibroblast cell viability was significantly greater than that of the MCF-7 cells. Conclusion:Our finding showed that Thymol appears to be toxic to MCF-7 cells at lower concentrations than fibroblasts after 24 hours of incubation. Pre-treatment with Thymol neutralized the oxidative effect of t-BHP in fibroblasts but was toxic for MCF-7 cells.Key Words: Breast Cancer, MCF-7 Cells, Oxidative Stress, tert-Butyl Hydroperoxide, Thymol     

Effect of organic materials addition on transformation of added manganese dioxide to alkali calcareous soils

Summary A study was made of the effect of addition and incubation of two organic materials to two alkali calcareous soils on the transformation undergone by added MnO₂. It is found that decomposition of added organic materials has a solubilizing effect on soil Mn and the added MnO₂ as it resulted in a temporary marked increase in water-soluble plus exchangeable Mn. This increase was accompanied by a decrease in the easily reducible Mn suggesting that part of it is transformed to the divalent form. The intermediate decomposition products form complexes with Mn which are soluble at the pH range of alkaline soils. A great part of the added MnO₂ was recovered in the easily reducible form while it was not extracted by the Na₂-EDTA solution. However, the Na₂-EDTA extractable Mn increased appreciably upon MnO₂ and organic materials addition and incubation, suggesting that part of the added oxide is transformed to the insoluble chelated form. A new hypothesis on the Mn cycle in soils is presented. It is based on oxidation-reduction, and production and decomposition of natural chelating agents during incubation.     

Transformation of cotton (Gossypium hirsutum L.) by Agrobacterium tumefaciens and regeneration of transgenic plants

Cotton (Gossypium hirsutum L.) cotyledon tissues have been efficiently transformed and plants have been regenerated. Cotyledon pieces from 12-day-old aseptically germinated seedlings were inoculated with Agrobacterium tumefaciens strains containing avirulent Ti (tumor-inducing) plasmids with a chimeric gene encoding kanamycin resistance. After three days cocultivation, the cotyledon pieces were placed on a callus initiation medium containing kanamycin for selection. High frequencies of transformed kanamycin-resistant calli were produced, more than 80% of which were induced to form somatic embryos. Somatic embryos were germinated, and plants were regenerated and transferred to soil. Transformation was confirmed by opine production, kanamycin resistance, immunoassay, and DNA blot hybridization. This process for producing transgenic cotton plants facilitates transfer of genes of economic importance to cotton.     

Gingival crevicular fluid infiltrating CD14+ monocytes promote inflammation in periodontitis

Periodontitis is a condition that occurs because of inflammation-mediated tissue degeneration. Many studies have been conducted to identify inflammatory molecules in periodontitis, but the well-defined role of cells from the immune system in the progression of periodontitis as well as in gingival tissue degeneration has not been appropriately established. The objective of the present study was to characterize the monocytes isolated from the gingival crevicular fluid (GCF) in patients with periodontitis. GCF was obtained from periodontitis patients and healthy controls. Cytokine levels of CCL2 were evaluated by ELISA in GCF samples. CD14+ monocytes were separated using magnetic sorting from GCF. RT-qPCR was performed to assess the gene expression. Cytometric bead array analysis was performed to analyze the levels of cytokines and chemokines in the secretome of cells. CD14+ monocytes from GCF secreted higher levels of CCL2 and showed elevated expression of genes responsible for monocyte migration. Additionally, upon lipopolysaccharide stimulation, these monocytes secreted higher levels of inflammatory cytokines and chemokines. This investigation aids in understanding the inflammatory microenvironment of periodontitis by characterizing GCF in terms of infiltrated CD14+ monocytes, cytokines, and molecules secreted by these monocytes, which are specific for cellular differentiation.     

Muscle glycolipids in inherited muscular dystrophy of chickens

Gangliosides and neutral glycolipids of muscles from normal and dystrophic chickens were studied. Total glycolipid content of the degenerating muscles was higher than the normal muscles. In addition, the myopathic muscles contained a ganglioside which was absent in the unaffected muscles from normal and dystrophic chickens. Based on the thin-layer chromatographic mobility, treatment with neuraminidases from Vibrio cholerae and Arthrobacter ureafaciens, and reactivity of the asialo-derivative towards anti-ganglio-N-triaosylceramide antibody, the dystrophic-specific ganglioside was tentatively identified as G_M2. Data obtained from young and old dystrophic chickens suggested a direct relationship of this ganglioside to muscular dystrophy.     

Non-antisense cellular responses to oligonucleotides

Oligonucleotides induce various cellular responses which are not due to the blockade of protein synthesis by an antisense mechanism. Oligonucleotides presenting double-stranded or G-quartet structures (ribo- or deoxyribonucleotides, phosphodiester or phosphorothioated) induce retraction of neurites and aggregation of chicken retinal cells within 10–20 h. This effect is reversible, non-toxic; it appears to require internalization and can be mimicked by treatment of the cells with an RGDS peptide. The oligonucleotides appear to trigger a cascade of intracellular events, affecting the adhesive properties of integrins. In addition, a subset of oligonucleotides induced platelet aggregation, probably through their interaction with membrane receptors. Recognition of these effects is important for the design and interpretation of antisense experiments.     

Flexibility of the shoulder joint measured as range of abduction in a large representative sample of men and women over 65 years of age

In a representative survey of 1000 elderly men and women aged over 65 years living in their own homes, assessments have been made of flexibility measured as range of shoulder abduction in addition to health status, psychological well-being and reported customary activity. The results for shoulder abduction were approximately normally distributed and the mean values (+/- 1 standard deviation) were as follows: - in men aged 65-74 years, 129 (+/- 14) degrees and aged over 74 years, 121 (+/- 19) degrees; in women aged 65-74 years, 124 (+/- 19) degrees and aged over 74 years, 114 (+/- 22) degrees. These mean values are about 30 degrees less than those accepted for younger subjects. Nearly half the distribution falls below the accepted threshold level of 120 degrees for adequate function. There were significant effects of sex and age (P less than 0.001); women had poorer flexibility and the reduction with age amounted to 10 degrees per decade. Multiple regression analysis showed that the effect of age was accounted for in part by health, strength and customary use. The effects of use were most marked in those with some disability. This suggests that maintained or increased use could offset some of the age-related loss of the range of shoulder movement.