A note on the brine shrimp Artemia in Tuz Lake (Turkey)

Population density, fecundity andreproduction period of Artemia sp. in TuzLake, Turkey, beside environmental factors, such as oxygen,temperature, salinity, pH and electrical conductivity werestudied during 1993 and 1994.Artemia sp. occurred at two stations at the coast.Overwintering cysts hatched in early May, when the population was composed of 90% metanauplii (93%at Y4 and 99% at Y5) and few adult females. Peak abundanceoccurred in late May, at 106to 114 ind.m^–3.     

Effects of different Rhododendron control methods in eastern beech (Fagus orientalis Lipsky) ecosystems in the western Black Sea region of Turkey

Intensive weed control and plot preparation practices have become a critical and integral part of productive beech forest management in Turkey’s coastal Black Sea region (BSR). This study was conducted in an eastern beech forest of 100+ year old in the BSR to evaluate ecosystem effects of three different experimental Rhododendron ponticum understory control methods with a randomised block design, including manual grubbing, foliar and cut stump spraying with imazapyr (Arsenal) and foliar and cut stump spraying with triclopyr (Garlon). Untreated vegetation plots served as controls. Evaluation of these treatments included their effects on understory and forest floor biomass and nutrients (C, N, P, S, K, Ca and Mg) and effects on soils, including bulk density, pH, soil nutrients (C, N, P and S), exchangeable cations (K, Ca and Mg) and soil cation exchange capacity (CEC). Grubbing and imazapyr treatments had greatly reduced the amount of understory biomass 5 years after application (P = 0.002). Triclopyr treatment also had a major effect on understory vegetation control, but by 5 years later, about 10% of the rhododendron originally present on these plots had gradually re‐sprouted and partially covered the plots. Five years after woody vegetation control treatments, at the 0‐ to 20‐cm depth, treatments did not appear to affect soil bulk density, pH and CEC. For the upper 20‐cm soil depth, the exchangeable soil K concentration at the 10‐ to 20‐cm depth on triclopyr‐treated plots was 33% higher than on grubbing plots, and it was twice that of imazapyr application plots. Imazapyr plots had almost 11 times more dead organic matter on the forest floor than there was on grubbing plots. Forest floor C concentrations on imazapyr plots were 26 and 14% greater than those on grubbing and triclopyr plots, respectively. Total ecosystem (forest floor + understory + soil exchangeable) Ca content was 50% higher on imazapyr plots than that on triclopyr plots, while the ecosystem K pool on imazapyr treatment plots was 27% lower than that on triclopyr plots. Herbicides can be used as an alternative for achieving some forest management objectives when other vegetation control methods are not feasible or economical. It is recommended that vegetation control not be used on steep slopes because of greater risk of soil erosion. There may be benefits in encouraging slash disposal by fire after imazapyr treatments, thus removing recalcitrant understory residues left on the forest floor and releasing the essential nutrients within them.     

Cisplatin cytotoxicity is enhanced with zoledronic acid in A549 lung cancer cell line: preliminary results of an in vitro study

We tested whether zoledronic acid, a biphosphonate with proposed apoptotic activity, augmented the cytotoxicity of cisplatin and/or gemcitabine in A549 lung cancer cell line. This cell line was subjected to different concentrations of the above chemotherapeutic agents and zoledronic acid. Cytotoxicity was assessed by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrasodium bromide) assay. Particularly, zoledronic acid in 100 micromolar (microM) concentration augmented the cytotoxicity by cisplatin 1microg/ml from 25% to 70% (Z=3.22, P=0.0072). A significant portion of cells underwent apoptosis with or without zoledronic acid, but more so with the combination treatment as assessed by an Annexin V-FITC apoptosis detection kit. However, 100microM zoledronic acid showed 50% cytotoxicity on its own, but failed to improve cytotoxicity by Gemcitabine. Thus, we show for the first time in a lung cancer cell line that zoledronic acid bears cytotoxic potential on its own and in conjunction with cisplatin. The clinical potential of this finding should be further studied.     

Curcumin prevents liver fat accumulation and serum fetuin-A increase in rats fed a high-fat diet

Fetuin-A is synthesized in the liver and is secreted into the bloodstream. Clinical studies suggest involvement of fetuin-A in metabolic disorders such as visceral obesity, insulin resistance, diabetes, and fatty liver. Curcumin is extracted from the rhizome Curcuma longa and has been shown to possess potent antioxidant, anticarcinogenic, anti-inflammatory, and hypoglycemic properties. In this study, we investigated the effect of curcumin treatment on serum fetuin-A levels as well as hepatic lipids and prooxidant–antioxidant status in rats fed a high-fat diet (HFD). Male Sprague–Dawley rats were divided into six groups. Group 1 was fed control diet (10 % of total calories from fat). Groups 2 and 3 were given curcumin (100 and 400 mg/kg bw/day, respectively ) by gavage for 8 weeks and were fed control diet. Group 4 was fed with HFD (60 % of total calories from fat). Groups 5 and 6 received HFD together with the two doses of curcumin, respectively. Curcumin treatment appeared to be effective in reducing liver triglycerides and serum fetuin-A levels. These findings suggest that the reduction of fetuin-A may contribute to the beneficial effects of curcumin in the pathogenesis of obesity.     

Synthesis of naphthalimide derivatives with potential anticancer activity,their comparative ds- and G-quadruplex-DNA binding studies and related biological activities

Molecular Biology Reports - Two new cytotoxic 1,8-naphthalimide derivatives have been synthesized and characterized. Their biological activities as cytotoxicity and antimicrobial activities and...     

Nitric oxide: a novel inducer for enhancement of microbial lipase production

The purpose of this study was to elucidate whether exogenous nitric oxide (NO) has a potential beneficial effect on lipase production capacity of some microorganisms. Sodium nitroprusside (SNP) was used as an exogenous NO donor in production medium. In comparison with the control (0 nM SNP), SNP concentrations from 10 to 100 nM induced lipase production in mesophilic bacterium Bacillus subtilis and cold-adapted yeast Yarrowia lipolytica. Especially, the maximum lipase activities for Y. lipolytica (81.2 U/L) and B. subtilis (74.5 U/L) were attained at 30 and 50 nM SNP concentrations, respectively. When compared to the control, the optimal SNP concentrations resulted in about 5.14 and 2.27-fold increases in lipase activities of B. subtilis and Y. lipolytica, respectively. Besides, it was found that the optimal SNP concentrations provided shorter incubation periods for lipase production. Conversely, no significant positive effect of exogenous NO on lipase production was determined for thermophilic bacterium Geobacillus stearothermophilus. This study showed for the first time that exogenous NO could be used as an inducer in the production of microbial lipases.     

Drosophila MUS312 interacts with the nucleotide excision repair endonuclease MEI-9 to generate meiotic crossovers

MEI-9 is the Drosophila homolog of the human structure-specific DNA endonuclease XPF. Like XPF, MEI-9 functions in nucleotide excision repair and interstrand crosslink repair. MEI-9 is also required to generate meiotic crossovers, in a function thought to be associated with resolution of Holliday junction intermediates. We report here the identification of MUS312, a protein that physically interacts with MEI-9. We show that mutations in mus312 elicit a meiotic phenotype identical to that of mei-9 mutants. A missense mutation in mei-9 that disrupts the MEI-9-MUS312 interaction abolishes the meiotic function of mei-9 but does not affect the DNA repair functions of mei-9. We propose that MUS312 facilitates resolution of meiotic Holliday junction intermediates by MEI-9.     

Deficiency of Dol-P-Man Synthase Subunit DPM3 Bridges the Congenital Disorders of Glycosylation with the Dystroglycanopathies

Alpha-dystroglycanopathies such as Walker Warburg syndrome represent an important subgroup of the muscular dystrophies that have been related to defective O-mannosylation of alpha-dystroglycan. In many patients, the underlying genetic etiology remains unsolved. Isolated muscular dystrophy has not been described in the congenital disorders of glycosylation (CDG) caused by N-linked protein glycosylation defects. Here, we present a genetic N-glycosylation disorder with muscular dystrophy in the group of CDG type I. Extensive biochemical investigations revealed a strongly reduced dolichol-phosphate-mannose (Dol-P-Man) synthase activity. Sequencing of the three DPM subunits and complementation of DPM3-deficient CHO2.38 cells showed a pathogenic p.L85S missense mutation in the strongly conserved coiled-coil domain of DPM3 that tethers catalytic DPM1 to the ER membrane. Cotransfection experiments in CHO cells showed a reduced binding capacity of DPM3(L85S) for DPM1. Investigation of the four Dol-P-Man-dependent glycosylation pathways in the ER revealed strongly reduced O-mannosylation of alpha-dystroglycan in a muscle biopsy, thereby explaining the clinical phenotype of muscular dystrophy. This mild Dol-P-Man biosynthesis defect due to DPM3 mutations is a cause for alpha-dystroglycanopathy, thereby bridging the congenital disorders of glycosylation with the dystroglycanopathies.