The p67(phox) activation domain regulates electron flow from NADPH to flavin in flavocytochrome b(558).

An activation domain in p67(phox) (residues within 199-210) is essential for cytochrome b(558)-dependent activation of NADPH superoxide (O2(-.)) generation in a cell-free system (Han, C.-H., Freeman, J. L. R., Lee, T., Motalebi, S. A., and Lambeth, J. D. (1998) J. Biol. Chem. 273, 16663-16668). To determine the steady state reduction flavin in the presence of highly absorbing hemes, 8-nor-8-S-thioacetamido-FAD ("thioacetamido-FAD") was reconstituted into the flavocytochrome, and the fluorescence of its oxidized form was monitored. Thioacetamido-FAD-reconstituted cytochrome showed lower activity (7% versus 100%) and increased steady state flavin reduction (28 versus <5%) compared with the enzyme reconstituted with native FAD. Omission of p67(phox) decreased the percent steady state reduction of the flavin to 4%, but omission of p47(phox) had little effect. The activation domain on p67(phox) was critical for regulating flavin reduction, since mutations in this region that decreased O2(-.) generation also decreased the steady state reduction of flavin. Thus, the activation domain on p67(phox) regulates the reductive half-reaction for FAD. This reaction is comprised of the binding of NADPH followed by hydride transfer to the flavin. Kinetic deuterium isotope effects along with K(m) values permitted calculation of the K(d) for NADPH. (R)-NADPD but not (S)-NADPD showed kinetic deuterium isotope effects on V and V/K of about 1.9 and 1.5, respectively, demonstrating stereospecificity for the R hydride transfer. The calculated K(d) for NADPH was 40 microM in the presence of wild type p67(phox) and was approximately 55 microM using the weakly activating p67(phox)(V205A). Thus, the activation domain of p67(phox) regulates the reduction of FAD but has only a small effect on NADPH binding, consistent with a dominant effect on hydride/electron transfer from NADPH to FAD.     

Assessment of Heavy Metal Pollution in Water and Sediments from the Ghalechay River,Baychebagh Copper Mine Area,Iran

The concentrations of selected heavy metals in sediments and waters in Baychebagh copper mine were determined using ICP-OES. Except for Co, the average concentrations of Cd, Cu, Pb, and Zn in sediments from the Ghalechay River in the district exceed the world-average shale and continental upper crust value. Enrichment factors for Pb, Cu, and Cd were significantly enriched in sediments, indicating environmental contamination. Geoaccumulation index calculated for different sampling stations indicates that the sediments are unpolluted with respect to Co and Zn while unpolluted to moderately polluted with Cu and highly polluted with Pb and Cd. The Sediment Quality Guidelines (SQGs) suggest that Cd and Pb may pose the highest risk for the environment. Sequential extraction analyses of sediments revealed that Cu, Co, Pb, and Zn bound to extractable, carbonate, reducible and oxidizable fractions are lower than residual fraction. About 10% of the total Pb was associated with the exchangeable fraction, indicating remobilization, while Cd (89%), Pb (73%) Co (58%), Cu (76%), and Zn (68%) closely associated with the residual and oxidizable fractions, resulting in their environmental immobility. The residual forms are not expected to be released under normal conditions in the river and could be considered an inert phase.     

A single-label phenylpyrrolocytidine provides a molecular beacon-like response reporting HIV-1 RT RNase H activity

6-Phenylpyrrolocytidine (PhpC), a structurally conservative and highly fluorescent cytidine analog, was incorporated into oligoribonucleotides. The PhpC-containing RNA formed native-like duplex structures with complementary DNA or RNA. The PhpC-modification was found to act as a sensitive reporter group being non-disruptive to structure and the enzymatic activity of RNase H. A RNA/DNA hybrid possessing a single PhpC insert was an excellent substrate for HIV-1 RT Ribonuclease H and rapidly reported cleavage of the RNA strand with a 14-fold increase in fluorescence intensity. The PhpC-based assay for RNase H was superior to the traditional molecular beacon approach in terms of responsiveness, rapidity and ease (single label versus dual). Furthermore, the PhpC-based assay is amenable to high-throughput microplate assay format and may form the basis for a new screen for inhibitors of HIV-RT RNase H.     

Chromium Supplementation Can Alleviate the Negative Effects of Heat Stress on Growth Performance,Carcass Traits,and Meat Lipid Oxidation of Broiler Chicks without Any Adverse Impacts on Blood Constituents

This study was conducted to determine the effects of dietary supplementation with Cr nicotinate and Cr chloride and their optimum inclusion rate on performance, carcass traits, meat oxidative stability, serum metabolites, hematological parameters, and liver chromium concentration in heat-stressed broilers. A total number of 420, 1-day-old male broiler chicks were randomly assigned to seven treatments with four replicates of 15 chicks. The dietary treatments consisted of the basal diet supplemented with 0 (control), 500, 1,000, and 1,500 μg/kg Cr in the form of Cr nicotinate and Cr chloride. Chicks were raised for 6 weeks in heat stress condition (33 ± 2°C). Supplements of organic and inorganic Cr particularly at 1,500 μg/kg incorporation increased feed consumption (P < 0.05) and body mass gain of broilers (P < 0.01). Cr supplementation increased carcass yield and decreased abdominal fat (P < 0.01). Supplementation of 1,500 μg/kg Cr nicotinate (P < 0.05) enhanced liver Cr concentration. Storage time increased lipid oxidation of meat (P < 0.01). Cr decreased lipid oxidation of breast and thigh muscles over 2 (P < 0.01) or 6 (P < 0.05) days of storage time. Birds fed 1,500 μg/kg Cr nicotinate, had lower concentration of serum glucose and triglyceride at 21 days (P < 0.05). Hematological parameters tested at 21 and 42 days, were not influenced. The results suggested that dietary Cr supplementation regardless of its source have a positive effect on productive, and carcass traits, also enhances oxidative stability of refrigerated meat in broilers reared under heat stress conditions.     

The impact of ant attendance on protecting <Emphasis Type="Italic">Aphis gossypii</Emphasis> against two aphidophagous predators and it’s role on the Intraguild Predation between them

In this study the changes in Aphis gossypii Glover populations tended by the homopteran- tending ant, Tapinoma simrothi Krausse when exposed to the natural enemies Chrysoperla carnea Stephens and Coccinellia septempunctata Mulsant was studied. We also studied the effect of ant’s attendance on the consequence of intraguild predation (IGP) between these two predators. The presence of ants T. simrothi had deterrent impact on natural enemies of A. gossypii compared to control aphid populations in absence of ants. Equally we observed that IGP between two aphid predators decreased when T. simrothi was present. The lowest IGP level was observed when both aphids and ants were present in the microcosm arena. In the microcosm arena the presence of ants had an indirect effect on the occurrence of IGP. Our results suggest that although the mutualistic ants have an indirect impact on the IGP by aphidophages predators, but their roles should not be ignored.     

Comparison of conditioned medium and direct co-culture of human granulosa cells on mouse embryo development

Although numerous investigations have demonstrated the beneficial effects of co-culture system of different somatic cells on in vitro development of embryos, the effects of conditioned-media of co-culture cells have not been well documented. The objective of this study was to compare the effects of human granulosa cells co-culture system and its conditioned medium on the developmental rate of mouse embryos in vitro. Two sets of experiments were undertaken: in the first one 317 mouse one-cell embryos were cultured in human granulosa cell co-culture system (GC). Ham's F10 medium conditioned with granulosa cells (CM) and non-conditioned Ham's F10 for 120 h. In the second experiment. 391 late two-cell embryos were cultured in the 3 fore-mentioned culture treatments for 72 h. Embryos were obtained from NMRI mice. Granulosa cells were collected from patients undergoing an IVF program during oocyte pickup. In the first set of experiments, 23.6, 14.5 and 11.1% of one-cell embryos passed two-cell block and continued growing to 4-cell in GC, CM and HF, respectively. This index in GC was significantly different from two other treatments. Also significantly more embryos reached blastocyst stage in GC compared with two other treatments. The blastocyst rate was not significantly different between CM and HF. In the second set of experiments the proportion of blastocyst stage was significantly higher in CM than that in HF and lower than that in GC. In conclusion, although human granulosa cell-conditioned medium has beneficial effects on mouse embryo development, it was not as effective as co-culture of these cells.     

Soils selenium level and esophageal cancer: An ecological study in a high risk area for esophageal cancer

ProjectGolestan province, located in northeast of Iran, has been known as a high risk area for esophageal cancer (EC). This study was conducted to assess the relationship between soils selenium (Se) level and development of EC in this region.ProceduresIn this ecological study, 135 blocks were identified in Golestan province based on geographical altitude and longitude on the map. One soil sample was collected from the center of each block. Then we investigated Se concentration in soil samples by flame atomic absorption spectrometry. Statistical analysis was performed by the Pearson correlation test and Student t-tests. P-values of less than 0.05 were considered as significant.ResultsThe mean±SD of soils Se level in Golestan province was 3.7±1.61 mg/kg. There was a positive correlation between soils Se level and EC rates in this area (P=0.03) (Pearson correlation coefficient=0.19). Soils Se concentration was significantly higher in high (4.13 mg/kg) than in the low (3.39 mg/kg) EC rate areas (P=0.01).ConclusionsWe found high soils Se concentration and a significant positive relationship between soils Se level and EC rate in Golestan province of Iran. So, high soils Se level may play a possible role in developing EC in this area, specifically in Turkmensahra (very high EC rates).     

Cottonseed Meal Bioactive Peptides as an Alternative to Antibiotic Growth Promoters in Broiler Chicks

The aim of this experiment was to evaluate the effects of bioactive peptides derived from enzymatic hydrolysis of cottonseed meal (CSBP) compared with zinc bacitracin, as an antibiotic growth promoter (AGP), on productive traits, serum lipid profile, and ileal microbial population in broiler chickens. A total number of 240-day-old broiler chicks (Ross 308) were allocated into 4 treatments, replicated 5 times based on a completely randomized design. The dietary treatments included a basal diet serving as control group, basal diet?+?40 mg/kg zinc bacitracin as AGP group, and the basal diet supplemented with 15 or 20 g/kg CSBP substituting equal quantity of maize and soybean meal. Performance traits, including daily weight gain, feed intake, feed conversion ratio (FCR), and livability were recorded. At the end of the study, serum lipid parameters, ileal microbial population, and economical indices were determined. The results indicated that feed intake and FCR increased (P?<?0.05) in birds receiving 20 g/kg CSBP over the entire period (1–35 days), but there was no significant effect of CSBP on body weight, although numerically higher than the control group. However, the antibiotic group showed a significant increase (P?<?0.05) in body weight and feed intake. Livability, European Production Efficiency Factor (EPEF), and European Broiler Index (EBI) significantly improved in broiler chickens fed antibiotic and 15 g/kg CSBP supplement (P?<?0.05). Adding 20 g/kg of CSBP to the diet significantly increased serum triglycerides and decreased low-density lipoproteins (LDL) compared to the control and antibiotic groups on day 35. The relative weight of abdominal fat and LDL to HDL ratio were significantly lower for CSBP and antibiotic treatments than the control group (P?<?0.05). Supplementation of antibiotic and both graded levels of CSBP decreased the ileum population of Escherichia coli (P?<?0.05). The current findings suggest that including CSBP in broiler diets may benefit production through improving growth rate of broilers and balancing gut microbiota population. In addition, CSBP could be considered as a potential alternative to antibiotics in an AGP free production system.

     

Differences in fennel seed responses to drought stress at the seed formation stage in sensitive and tolerant genotypes

To understand the effects of drought on fennel seed production and determine the underlying molecular processes, various fennel genotypes were exposed to drought stress. The yield and quality, including aromatic oil content, of fennel seeds were reduced by drought during seed development. To explore drought-induced biological processes in fennel, a label-free/gel-free proteomic analysis was performed. In Gaziantep and Tatmaj cultivars, which are sensitive and tolerant fennel genotypes, respectively, 106 and 92 drought-responsive proteins were identified. Comparison of protein-functional profiles indicated that proteins classified in stress, cell, and protein synthesis/degradation categories consisted important responsive mechanisms against drought stress. Pathway analysis visualized that the tricarboxylic acid cycle is important for both cultivars. In Tatmaj, moderate activation of proteins related to oxidative pentose phosphate pathway was detected along with an increase in photosynthesis-related proteins. Furthermore, cluster analysis of drought-responsive proteins using protein abundance at milky, dough, and mature stages identified protein homeostasis as a mechanism of drought tolerance in fennel. These results suggest that coordinated energy consumption and supply might be a drought-tolerance mechanism in fennel plants.