Drought-induced oxidative damage and antioxidant responses in peanut (<Emphasis Type="Italic">Arachis</Emphasis><Emphasis Type="Italic">hypogaea</Emphasis> L.) seedlings

Two cultivars of peanut (Arachis hypogaea L.) which were designated as resistant (Florispan) and sensitive (Gazipasa) according to their growth retardation under drought stress conditions were compared for their oxidative damage and antioxidant responses. Sixteen days-old peanut seedlings were subjected to PEG-6000 solutions of two different osmotic potentials; −0.4 and −0.8 MPa, and various growth parameters, photosystem II activity, changes in malondialdehyde (MDA), hydrogen peroxide (H₂O₂) and proline levels, activities of ascorbate peroxidase (APX), catalase (CAT), peroxidase (POX) and gluthatione reductase (GR) enzymes were determined. Both cultivars exhibited water deficit at −0.8 MPa osmotic potential of PEG-6000 and H₂O₂ levels significantly increased during exposure to −0.4 MPa osmotic potential. However, H₂O₂ levels were under control in both cultivars at exposure to −0.8 MPa osmotic potential. Significant proline accumulation was observed in the tissues of cv. Florispan at −0.8 MPa osmotic potential, whereas proline accumulation did not appear to be an essential part of the protection mechanism against drought in cv. Gazipasa. No significant variation in chlorophyll fluorescence values were detected in neither of the cultivars. Enzyme activity measurements revealed that Gazipasa copes well with lesser magnitudes of drought stress by increasing the activity of mainly APX, and during harsh stress conditions, only APX maintains its activity in the tissues. In cultivar Florispan, GR activity appears to take role in lesser magnitudes of drought stress, whereas CAT and APX activities appear to be very crucial antioxidative defenses during intense stress conditions. The results indicate that, the level of proline and activities of the enzymes CAT and APX are important mechanisms for the maintenance of drought tolerance in peanut plants.     

Processive cytoskeletal motors studied with single-molecule fluorescence techniques

Processive cytoskeletal motors from the myosin, kinesin, and dynein families walk on actin filaments and microtubules to drive cellular transport and organization in eukaryotic cells. These remarkable molecular machines are able to take hundreds of successive steps at speeds of up to several microns per second, allowing them to effectively move vesicles and organelles throughout the cytoplasm. Here, we focus on single-molecule fluorescence techniques and discuss their wide-ranging applications to the field of cytoskeletal motor research. We cover both traditional fluorescence and sub-diffraction imaging of motors, providing examples of how fluorescence data can be used to measure biophysical parameters of motors such as coordination, stepping mechanism, gating, and processivity. We also outline some remaining challenges in the field and suggest future directions.     

Structural, technological and productivity analyses of rainbow trout (Oncorhynchus mykiss) farms in the Marmara region, Turkey

This study analyses the structural, technological performance components and the overall productivity of inland rainbow trout ( Oncorhynchus mykiss ) farms in the Marmara region, Turkey. Of 81 active farms, 36 were small scale (1–10 t year⁻¹), 32 medium-sized (11–30 t year⁻¹) and 13 large production units (over 30 t year⁻¹). Sufficient data for this study were collected from 70 farms for inclusion in the analyses; 59.3% were so-called combined farms (hatchery and grow-out), 37.9% on-growing farms (for market production) and 2.9% producing juvenile fish only for stocking or for supply to grow-out farms. Juvenile fish production was largely conducted on large farms. Capacity utilization (102.8%) of the large farms was most similar to their projected capacity. Many large farms (43.9%) use high-tech utilities and tools. Small farms mostly use concrete ponds whereas most medium and large-scale farms use fiberglass tanks. Medium and large-scale farms were found to be more successful in broodstock management, fertilization, hatching success and survival rate of juvenile fish. Fish stocking density in medium-sized farms (21.8 kg m⁻³) was higher than in small-scale (14.5 kg m⁻³) and large-scale farms (15.5 kg m⁻³). Overall feed conversion ratio for all farms was estimated as 1.2. From the survey results it appears that production capacity planning was calculated more accurately in the projection phase for small and large-scale farms rather than for medium-sized farms. Medium and large-scale farms were more successful in terms of performance (good experience, good structural and technological capabilities).     

Plasma selenium levels in rheumatoid arthritis

The plasma selenium (Se) levels were determined in patients with rheumatoid arthritis (RA) and healthy controls. Plasma Se levels in 60 patients were found to be significantly lower than those in 60 normal, healthy controls (p<0.001). Similar significant differences were determined in sex-matched comparisons between patients and controls (p<0.001) but there was no significant difference in plasma Se levels in sex-matched comparisons in both groups (p>0.05). Our results suggest that Se is an important factor in RA.     

IL-12Rβ1 deficiency in two of fifty children with severe tuberculosis from Iran, Morocco, and Turkey

Background and Objectives

In the last decade, autosomal recessive IL-12Rβ1 deficiency has been diagnosed in four children with severe tuberculosis from three unrelated families from Morocco, Spain, and Turkey, providing proof-of-principle that tuberculosis in otherwise healthy children may result from single-gene inborn errors of immunity. We aimed to estimate the fraction of children developing severe tuberculosis due to IL-12Rβ1 deficiency in areas endemic for tuberculosis and where parental consanguinity is common.

Methods and Principal Findings

We searched for IL12RB1 mutations in a series of 50 children from Iran, Morocco, and Turkey. All children had established severe pulmonary and/or disseminated tuberculosis requiring hospitalization and were otherwise normally resistant to weakly virulent BCG vaccines and environmental mycobacteria. In one child from Iran and another from Morocco, homozygosity for loss-of-function IL12RB1 alleles was documented, resulting in complete IL-12Rβ1 deficiency. Despite the small sample studied, our findings suggest that IL-12Rβ1 deficiency is not a very rare cause of pediatric tuberculosis in these countries, where it should be considered in selected children with severe disease.

Significance

This finding may have important medical implications, as recombinant IFN-γ is an effective treatment for mycobacterial infections in IL-12Rβ1-deficient patients. It also provides additional support for the view that severe tuberculosis in childhood may result from a collection of single-gene inborn errors of immunity.     

Genotoxic and Histopathological Effects of Water Pollution on Two Fish Species, <Emphasis Type="Italic">Barbus capito pectoralis</Emphasis> and <Emphasis Type="Italic">Chondrostoma nasus</Emphasis> in the Büyük Menderes River,Turkey

The genotoxic and histopathological effects of water pollution were investigated on two fish species caught from the Buyuk Menderes River and from its tributary, the Cine Stream. The Buyuk Menderes basin is an important agricultural area in Turkey. The levels of copper, zinc, cadmium, cobalt, and lead were measured at the surface of the water and in gills, liver, and muscle tissue of Chondrostoma nasus and Barbus capito pectoralis. In some tissues, the concentrations of some of these metals exceeded acceptable levels for human consumption. Zinc was found to be the most abundant metal in water and tissues. Maximal metal accumulation was observed in the liver. To detect the genotoxic potential of contaminants, the formation of micronucleus in erythrocytes was used as indicator of chromosomal damage. The frequency of micronucleus formation did not show significant differences between locations and controls in B. capito pectoralis caught from three locations and C. nasus from two locations. The histological changes included significant decreases of the mean lengths of primary and secondary lamellae. In gills epithelia, we observed cellular proliferation that developed Because of secondary lamellae fusion, ballooning degenerations, or club deformation of secondary lamellae and cystic structures in secondary lamellae. In the liver, the changes included swollen and ruptured parenchymal cells, loss of cord structure, vacuoles filled with cellular debris, focal necrosis, and a significant increase in Kupffer cells.     

Serum mineral levels at pregnancy and postpartum in single and twin pregnant sheep

This study was performed to investigate calcium (Ca), inorganic phosphorus (P), potassium (K), magnesium (Mg), and chlorine (Cl) levels in blood serum at d 60, 100, and 150 of gestation and at d 45 after parturition and to find out the significance of differences for macromineral levels during these stages of single or twin gestation in Akkaraman sheep. Blood samples of 30 apparently healthy pregnant Akkaraman sheep (15 single pregnancies, 15 twin pregnancies) were used. The samples were analyzed using a biochemical analyzer for Ca, P, Na, K, and Mg concentrations and using the Schales method for Cl levels. A statistically significant decrease (p<0.001 and p<0.05) was found on d 100 of pregnancy for Ca levels and for serum inorganic P levels in both groups. Twin pregnant sheep were found to have lower (p<0.05) serum Ca and inorganic P levels than sheep pregnant with one fetus on d 100 and 150. Significant decreases (p>0.05, p <0.01) for serum Mg levels in both groups were recorded on d 100 and 150 of pregnancy. There were significant increases (p<0.01) in serum Cl levels on d 100 in single and twin pregnant sheep.     

pH-Induced Conformational Change of the β-Barrel-Forming Protein OmpG Reconstituted into Native E. coli Lipids

A gating mechanism of the β-barrel-forming outer membrane protein G (OmpG) from Escherichia coli was recently presented. The mechanism was based on X-ray structures revealed from crystals grown from solubilized OmpG at both neutral pH and acidic pH. To investigate whether these conformations represent the naturally occurring gating mechanism, we reconstituted OmpG in native E. coli lipids and applied high-resolution atomic force microscopy. The reconstituted OmpG molecules assembled into both monomers and dimers. Single monomeric and dimeric OmpG molecules showed open channel entrances at pH 7.5 and at room temperature. The extracellular loops connecting the β-strands that form the transmembrane β-barrel pore exhibited elevated structural flexibility. Upon lowering the pH to 5.0, the conformation of OmpG molecules changed to close the extracellular entrance of their channel. It appears that one or more of the extracellular loops collapsed onto the channel entrance. This conformational change was fully reversible. Our data confirm that the previously reported gating mechanism of OmpG occurs at physiological conditions in E. coli lipid membranes.