Importance of pfkA for rapid growth of Enterobacter cloacae during colonization of crop seeds

Enterobacter cloacae A-11 is a prototrophic, glycolytic mutant of strain 501R3 with a single transposon insertion in pfkA. The populations of strain A-11 on cucumber and radish seeds were smaller than the populations of strain 501R3 in natural soil, but the populations of these two strains on pea, soybean, sunflower, and sweet corn seeds were similar (D. P. Roberts, P. D. Dery, I. Yucel, J. Buyer, M. A. Holtman, and D. Y. Kobayashi, Appl. Environ. Microbiol. 65:2513-2519, 1999). The net effect of the mutation in pfkA in vitro was a shift from rapid growth on certain carbohydrates detected in seed exudates to much slower growth on other carbohydrates, amino acids, and organic acids. The impact of the mutation in pfkA was greatest on the growth rate of E. cloacae on the seeds that released the smallest quantities of fructose, other carbohydrates, and amino acids. Corn, pea, soybean, and sunflower seeds released total amounts of carbohydrates and amino acids at rates that were approximately 10- to 100-fold greater than the rates observed with cucumber and radish seeds for the first 24 h after inhibition began. The growth rate of strain A-11 was significantly less (50% less) than the growth rate of strain 501R3 on radish seeds, and the growth rate of strain A-11 was too low to estimate on cucumber seeds in sterile sand for the first 24 h after inhibition began. The growth rate of strain A-11 was also significantly lower on soybean seeds, but it was only 17% lower than the growth rate of strain 501R3. The growth rates of strains 501R3 and A-11 were similar on pea, sunflower, and corn seeds in sterile sand for the first 30 h after imbibition began. Large reductions in the growth rates of strain A-11 on seeds were correlated with subsequent decreased levels of colonization of seeds compared to the levels of colonization of strain 501R3. The strain A-11 populations were significantly smaller than the strain 501R3 populations only on radish and cucumber seeds. The mutation in pfkA appears to decrease the level of colonization by E. cloacae for seeds that release small quantities of reduced carbon compounds by decreasing the size of the pool of compounds that support rapid growth by this bacterium.     

Pneumolysin activates the NLRP3 inflammasome and promotes proinflammatory cytokines independently of TLR4

Pneumolysin (PLY) is a key Streptococcus pneumoniae virulence factor and potential candidate for inclusion in pneumococcal subunit vaccines. Dendritic cells (DC) play a key role in the initiation and instruction of adaptive immunity, but the effects of PLY on DC have not been widely investigated. Endotoxin-free PLY enhanced costimulatory molecule expression on DC but did not induce cytokine secretion. These effects have functional significance as adoptive transfer of DC exposed to PLY and antigen resulted in stronger antigen-specific T cell proliferation than transfer of DC exposed to antigen alone. PLY synergized with TLR agonists to enhance secretion of the proinflammatory cytokines IL-12, IL-23, IL-6, IL-1β, IL-1α and TNF-α by DC and enhanced cytokines including IL-17A and IFN-γ by splenocytes. PLY-induced DC maturation and cytokine secretion by DC and splenocytes was TLR4-independent. Both IL-17A and IFN-γ are required for protective immunity to pneumococcal infection and intranasal infection of mice with PLY-deficient pneumococci induced significantly less IFN-γ and IL-17A in the lungs compared to infection with wild-type bacteria. IL-1β plays a key role in promoting IL-17A and was previously shown to mediate protection against pneumococcal infection. The enhancement of IL-1β secretion by whole live S. pneumoniae and by PLY in DC required NLRP3, identifying PLY as a novel NLRP3 inflammasome activator. Furthermore, NLRP3 was required for protective immunity against respiratory infection with S. pneumoniae. These results add significantly to our understanding of the interactions between PLY and the immune system.     

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.     

Formulation and <Emphasis Type="Italic">In vitro</Emphasis> Characterization of Eudragit® L100 and Eudragit® L100-PLGA Nanoparticles Containing Diclofenac Sodium

The aim of this study was to formulate and characterize Eudragit® L100 and Eudragit® L100-poly(lactic-co-glycolic acid) (PLGA) nanoparticles containing diclofenac sodium. Diclofenac generates severe adverse effects with risks of toxicity. Thus, nanoparticles were prepared to reduce these drawbacks in the present study. These nanoparticles were evaluated for surface morphology, particle size and size distribution, percentage drug entrapment, and in vitro drug release in pH 6.8. The prepared nanoparticles were almost spherical in shape, as determined by atomic force microscopy. The nanoparticles with varied size (241–274 nm) and 25.8–62% of entrapment efficiency were obtained. The nanoparticles formulations produced the release profiles with an initial burst effect in which diclofenac sodium release ranged between 38% and 47% within 4 h. The extent of drug release from Eudragit® L100 nanoparticles was up to 92% at 12 h. However, Eudragit®/PLGA nanoparticles showed an initial burst release followed by a slower sustained release. The cumulative release at 72 h was 56%, 69%, and 81% for Eudragit®/PLGA (20:80), Eudragit®/PLGA (30:70) and Eudragit®/PLGA (50:50) nanoparticles, respectively. The release profiles and encapsulation efficiencies depended on the amount of Eudragit in the blend. These data demonstrated the efficacy of these nanoparticles in sustaining the diclofenac sodium release profile.     

Sleep disturbances and excessive daytime sleepiness in migraine: A comparison between comorbidities and disability

Sleep and Biological Rhythms - Many studies have investigated the association between headache and sleep disorders, but few have focused on migraine. The goal of this study was to evaluate sleep...     

The relations between antioxidant enzymes and chlorophyll fluorescence parameters in common bean cultivars differing in sensitivity to drought stress

Effects of the antioxidant system and chlorophyll fluorescence on drought tolerance of four common bean (Phaseolus vulgaris L.) cultivars were studied. The cultivars were positioned in the order of a decrease in their drought tolerance: Yakutiye, Pinto Villa, Ozayse, and Zulbiye on the basis of changes in the water potential, stomatal conductance, photosynthetic pigment content, and lipid peroxidation. Under drought conditions, the level of H₂O₂ was not changed in cv. Pinto Villa but decreased in other cultivars. Antioxidant enzymes (superothide dismutase (SOD), guaiacol peroxidase (GPX), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR)) were generally activated in all cultivars. Interestingly, CAT, APX, and GR activities were not changed in cv. Pinto Villa, APX activity decreased in cv. Yakutiye, and CAT activity was not changed in cv. Zulbiye. The increases in SOD and GPX activities in cv. Ozayse were higher than in other cultivars. Drought stress reduced the effective quantum yield of PS2 (Φ_PS2) and the photochemical quenching (q_p), while it increased nonphotochemical quenching (NPQ) in all cultivars. The reduction or increase was more pronounced in cv. Zulbiye. There were generally significant correlations between q_p, NPQ, and ROS scavenging by SOD and APX. Also, there were significant correlations between SOD and q_p in tolerant cultivars and APX and q_p in sensitive ones. The results indicate that activation of SOD and APX was closely related to the efficiency of PS2 in common bean cultivars. This interaction was essential for protection of photosystems and plant survival under drought.     

The role of curcumin on intestinal oxidative stress,cell proliferation and apoptosis after ischemia/reperfusion injury in rats

The aim of this study was to demonstrate the role of curcumin on oxidative stress, cell proliferation and apoptosis in the rat intestinal mucosa after ischemia/reperfusion (I/R). A total of 30 male Wistar albino rats were divided into three groups: sham, I/R and I/R+ curcumin; each group contain 10 animals. Sham group animals underwent laparotomy without I/R injury. After I/R groups animals underwent laparotomy, 1 h of superior mesenteric artery ligation were followed by 1 h of reperfusion. In the curcumin group, 3 days before I/R, curcumin (100 mg/kg) was administered by gastric gavage. All animals were sacrificed at the end of reperfusion and intestinal tissues samples were obtained for biochemical and histopathological investigation in all groups. Curcumin treatment significantly decreased the elevated tissue malondialdehyde levels and increased of reduced superoxide dismutase, and glutathione peroxidase enzyme activities in intestinal tissues samples. I/R caused severe histopathological injury including mucosal erosions and villous congestion and hemorrhage. Curcumin treatment significantly attenuated the severity of intestinal I/R injury, with inhibiting of I/R-induced apoptosis and cell proliferation. These results suggest that curcumin treatment has a protective effect against intestinal damage induced by intestinal I/R. This protective effect is possibly due to its ability to inhibit I/R-induced oxidative stress, apoptosis and cell proliferation.     

Assessment of DNA damage in glue sniffers by use of the alkaline comet assay

Toluene is used widely, not only in industry, but also in households where toluene exposure and abuse can occur. To estimate the genotoxic risk of toluene exposure, DNA damage was determined in peripheral lymphocytes of 20 glue sniffers and 20 age-matched controls by use of the alkaline comet assay. Urinary hippuric acid and o-cresol excretion rates, which are used as a marker for toluene exposure, were also measured in sniffers and compared with historical control values. The increase in genetic damage in sniffers was statistically significant as compared to control subjects (P<0.0001). The mean values of the hippuric acid and o-cresol excretion rate for glue sniffers was 73- and 1582-fold higher, respectively, than in controls and confirms the putative exposure. Education of the general public and efforts to keep adolescents away from volatile solvent-based products, which may lead to a desire of sniffing in the future, would be advisable.     

The effects of PDE5 inhibitory drugs on renal ischemia/reperfusion injury in rats

The aim of the present study was to evaluate the effects of phosphodiesterase type 5 (PDE5) inhibitory drugs, Tadalafil and Sildenafil, on inducible NOS (iNOS), endothelial NOS (eNOS) and p53 genes expressions and apoptosis in ischemia/reperfusion (I/R) induced oxidative injury in rat renal tissue. Eighty Sprague-Dawley rats (300-350?g) were divided into four groups. In ischemia/reperfusion group, rats were subjected to renal ischemia by clamping the left pedicle for 60?min, and then reperfused for 90?min. On the other hand, in other two groups the rats were individually pretreated with Tadalafil and Sildenafil 1?h before the induction of ischemia. Malondialdehyde (MDA) is determined in renal tissue homogenates by high-performance liquid chromatography, the number of apoptotic cell were calculated by TUNEL method and p53 and eNOS expression were detected with immunohistochemistry. On the other hand, myeloperoxidase (MPO) levels were measured by spectrophotometric method and the mRNA level of iNOS in renal tissue was determined by Real-time PCR (RT-PCR). Our results indicate that MDA and MPO levels were increased in the I/R group than those in the control group. Both Tadalafil and Sildenafil treatment decreased the MDA levels in ischemia/reperfusion group, whereas this effect was more potent with Sildenafil. RT-PCR results showed that, iNOS gen expression increased in the I/R group, but decreased in the PDE5 inhibitory drugs treated group. Apoptotic cells, eNOS levels and p53 positive cells were also decreased in PDE5 inhibitory drugs treated group. We suggest that Tadalafil and Sildenafil have beneficial effects against I/R related renal tissue injury and this protective effect is clearer for Sildenafil than Tadalafil.