Depsidone constituents from the quintaria group of Nephroma species

A new lichen depsidone was isolated, in the form of its triacetate derivative from the acetylated extracts of Nephroma antarcticum and has been demonstrated to be hypoconstictic acid-triacetate. Two related depsidones, hypostictic acid hyposalazinic acid, were isolated from N. australe.     

Cellular localization and functional expression of P-glycoprotein in rat astrocyte cultures

We investigated the cellular/subcellular localization and functional expression of P-glycoprotein, an ATP-dependent membrane-associated efflux transporter, in astrocytes, a brain parenchyma compartment that is poorly characterized for the expression of membrane drug transporters. Analyses were carried out on primary cultures of astrocytes isolated from the cerebral cortex of neonatal Wistar rats and CTX TNA2, an immortalized rat astrocyte cell line. Both cell cultures display morphological features typical of type I astrocytes. RT-PCR analysis revealed mdr1a and mdr1b mRNA in primary cultures of astrocytes and in CTX TNA2 cells. Western blot analysis using the P-glycoprotein monoclonal C219 antibody detected a single band of appropriate size in both cell systems. Immunocytochemical analysis using the monoclonal antibodies C219 and MRK16 labeled P-glycoprotein along the plasma membrane, caveolae, coated vesicles and nuclear envelope. Immunoprecipitation studies using the caveolin-1 polyclonal H-97 antibody demonstrated that P-glycoprotein is physically associated with caveolin-1 in both cell culture systems. The accumulation of [(3)H]digoxin (an established P-glycoprotein substrate) by the astrocyte cultures was significantly enhanced in the presence of standard P-glycoprotein inhibitors and an ATP depleting agent. These results demonstrate the cellular/subcellular location and functional expression of P-glycoprotein in rat astrocytes and suggest that this glial compartment may play an important role in the regulation of drug transport in the CNS.     

Experimental evaluation of the relationship between lethal or non-lethal virulence and transmission success in malaria parasite infections

Background

Theoretical studies suggest that direct and indirect selection have the potential to cause substantial evolutionary change in female mate choice. Similarly, sexual selection is considered a strong force in the evolution of male attractiveness and the exaggeration of secondary sexual traits. Few studies have, however, directly tested how female mate choice and male attractiveness respond to selection. Here we report the results of a selection experiment in which we selected directly on female mating preference for attractive males and, independently, on male attractiveness in the guppy, Poecilia reticulata. We measured the direct and correlated responses of female mate choice and male attractiveness to selection and the correlated responses of male ornamental traits, female fecundity and adult male and female survival.

Results

Surprisingly, neither female mate choice nor male attractiveness responded significantly to direct or to indirect selection. Fecundity did differ significantly among lines in a way that suggests a possible sexually-antagonistic cost to male attractiveness.

Conclusions

The opportunity for evolutionary change in female mate choice and male attractiveness may be much smaller than predicted by current theory, and may thus have important consequences for how we understand the evolution of female mate choice and male attractiveness. We discuss a number of factors that may have constrained the response of female choice and male attractiveness to selection, including low heritabilities, low levels of genetic (co)variation in the multivariate direction of selection, sexually-antagonistic constraint on sexual selection and the "environmental covariance hypothesis".

     

The Use of Bayesian Networks to Assess the Quality of Evidence from Research Synthesis: 2. Inter-Rater Reliability and Comparison with Standard GRADE Assessment

Background

The grades of recommendation, assessment, development and evaluation (GRADE) approach is widely implemented in systematic reviews, health technology assessment and guideline development organisations throughout the world. We have previously reported on the development of the Semi-Automated Quality Assessment Tool (SAQAT), which enables a semi-automated validity assessment based on GRADE criteria. The main advantage to our approach is the potential to improve inter-rater agreement of GRADE assessments particularly when used by less experienced researchers, because such judgements can be complex and challenging to apply without training. This is the first study examining the inter-rater agreement of the SAQAT.

Methods

We conducted two studies to compare: a) the inter-rater agreement of two researchers using the SAQAT independently on 28 meta-analyses and b) the inter-rater agreement between a researcher using the SAQAT (who had no experience of using GRADE) and an experienced member of the GRADE working group conducting a standard GRADE assessment on 15 meta-analyses.

Results

There was substantial agreement between independent researchers using the Quality Assessment Tool for all domains (for example, overall GRADE rating: weighted kappa 0.79; 95% CI 0.65 to 0.93). Comparison between the SAQAT and a standard GRADE assessment suggested that inconsistency was parameterised too conservatively by the SAQAT. Therefore the tool was amended. Following amendment we found fair-to-moderate agreement between the standard GRADE assessment and the SAQAT (for example, overall GRADE rating: weighted kappa 0.35; 95% CI 0.09 to 0.87).

Conclusions

Despite a need for further research, the SAQAT may aid consistent application of GRADE, particularly by less experienced researchers.     

Daily physical activity in ankylosing spondylitis: validity and reliability of the IPAQ and SQUASH and the relation with clinical assessments

Introduction

The aim of this study was to investigate the construct validity and test-retest reliability of the International Physical Activity Questionnaire (IPAQ; long form) and the Short QUestionnaire to Assess Health-enhancing physical activity (SQUASH) and to investigate the relation between daily physical activity and clinical assessments in patients with ankylosing spondylitis (AS).

Methods

For validity, the self-report questionnaires IPAQ and SQUASH were compared with daily physical activity assessed with the ActiGraph accelerometer during 7 consecutive days in 63 AS outpatients. For reliability, the IPAQ and SQUASH were administered twice approximately 1 week apart in 52 AS outpatients. In all 115 patients, clinical assessments were performed at the outpatient clinic.

Results

IPAQ and SQUASH total scores correlated significantly with accelerometer outcome: ρ = 0.38 and r = 0.35, respectively. Intraclass correlation coefficients between first and second assessments of the IPAQ and SQUASH were 0.83 and 0.89, respectively. Bland-Altman analyses showed no systemic bias, but in particular for the IPAQ the 95% limits of agreement were wide. Daily physical activity assessed by accelerometer, IPAQ, and SQUASH correlated significantly with disease activity, physical activity, and quality of life. A relation with spinal mobility was found only for the accelerometer and SQUASH. The direction of these correlations indicates that higher daily physical activity is related to lower disease activity and better physical function, spinal mobility and quality of life.

Conclusions

Both physical activity questionnaires showed modest construct validity. The SQUASH showed good test-retest reliability, superior to the IPAQ. These results indicate that the SQUASH is more suitable than the IPAQ to assess daily physical activity in AS population studies. However, it is desirable to add questions on AS-specific physical activity. Further studies are needed to investigate the causality of the relation between daily physical activity and clinical assessments.     

Salmonella Typhimurium-specific bacteriophage ΦSH19 and the origins of species specificity in the Vi01-like phage family

Background

PHYVV and PepGMV are plant viruses reported in Mexico and Southern US as causal agents of an important pepper disease known as "rizado amarillo". Mixed infections with PHYVV and PepGMV have been reported in several hosts over a wide geographic area. Previous work suggested that these viruses might interact at the replication and/or movement level in a complex manner. The aim of present report was to study some aspects of a synergistic interaction between PHYVV and PepGMV in pepper plants. These include analyses of symptom severity, viral DNA concentration and tissue localization of both viruses in single and mixed infections.

Results

Mixed infections with PepGMV and PHYVV induced symptoms more severe than those observed in single viral infections. Whereas plants infected with either virus (single infection) presented a remission stage with a corresponding decrease in viral DNA levels, double-infected plants did not present symptom remission and both viral DNA concentrations dramatically increased. In situ hybridization experiments revealed that both viruses are restricted to the vascular tissue. Interestingly, the amount of viral DNA detected was higher in plants inoculated with PepGMV than that observed in PHYVV-infected plants. During mixed infections, the location of both viruses remained similar to the one observed in single infections, although the number of infected cells increases. Infections with the tripartite mixture PHYVV (A+B) + PepGMV A produced a similar synergistic infection to the one observed after inoculation with both full viruses. On the contrary, tripartite mixture PepGMV (A+B) + PHYVV A did not produce a synergistic interaction. In an attempt to study the contribution of individual genes to the synergism, several mutants of PHYVV or PepGMV were inoculated in combination with the corresponding wild type, second virus (wt PepGMV or wt PHYVV). All combinations tested resulted in synergistic infections, with exception of the TrAP mutant of PepGMV (PepGMV TrAP-) + PHYVV.

Conclusion

In this report, we have demonstrated that synergistic interaction between PHYVV and PepGMV during a mixed infection is mainly due to an increased DNA concentration of both viruses, without any noticeable effect on the localization of either virus on infected plant tissue. Our results have shown that the viral component A from PepGMV is important for synergism during PHYVV-PepGMV mixed infections.     

Whole plant response of Pongamia pinnata to drought stress tolerance revealed by morpho-physiological,biochemical and transcriptome analysis

Molecular Biology Reports - Pongamia is considered an important biofuel species worldwide. Drought stress in the early growth stages of Pongamia influences negatively on the germination and...     

Tempol modulates changes in xenobiotic permeability and occludin oligomeric assemblies at the blood-brain barrier during inflammatory pain

Our laboratory has shown that λ-carrageenan-induced peripheral inflammatory pain (CIP) can alter tight junction (TJ) protein expression and/or assembly leading to changes in blood-brain barrier xenobiotic permeability. However, the role of reactive oxygen species (ROS) and subsequent oxidative stress during CIP is unknown. ROS (i.e., superoxide) are known to cause cellular damage in response to pain/inflammation. Therefore, we examined oxidative stress-associated effects at the blood-brain barrier (BBB) in CIP rats. During CIP, increased staining of nitrosylated proteins was detected in hind paw tissue and enhanced presence of protein adducts containing 3-nitrotyrosine occurred at two molecular weights (i.e., 85 and 44 kDa) in brain microvessels. Tempol, a pharmacological ROS scavenger, attenuated formation of 3-nitrotyrosine-containing proteins in both the hind paw and in brain microvessels when administered 10 min before footpad injection of λ-carrageenan. Similarly, CIP increased 4-hydroxynoneal staining in brain microvessels and this effect was reduced by tempol. Brain permeability to [(14)C]sucrose and [(3)H]codeine was increased, and oligomeric assemblies of occludin, a critical TJ protein, were altered after 3 h CIP. Tempol attenuated both [(14)C]sucrose and [(3)H]codeine brain uptake as well as protected occludin oligomers from disruption in CIP animals, suggesting that ROS production/oxidative stress is involved in modulating BBB functional integrity during pain/inflammation. Interestingly, tempol administration reduced codeine analgesia in CIP animals, indicating that oxidative stress during pain/inflammation may affect opioid delivery to the brain and subsequent efficacy. Taken together, our data show for the first time that ROS pharmacological scavenging is a viable approach for maintaining BBB integrity and controlling central nervous system drug delivery during acute inflammatory pain.