Expression, purification and characterization of recombinant phosphomannomutase and GDP-{alpha}-D-mannose pyrophosphorylase from Salmonella enterica, group B, for the synthesis of GDP-{alpha}-D-mannose from D-mannose

The genes rfbK and rfbM from the rfb cluster (O-antigen biosynthesis)of Salmonella enterica, group B, encoding for the enzymes phosphomannomutase(EC 5.4.2.8 [EC] ) and GDP-     

Methods for identifying SNP interactions: a review on variations of Logic Regression, Random Forest and Bayesian logistic regression

Due to advancements in computational ability, enhanced technology and a reduction in the price of genotyping, more data are being generated for understanding genetic associations with diseases and disorders. However, with the availability of large data sets comes the inherent challenges of new methods of statistical analysis and modeling. Considering a complex phenotype may be the effect of a combination of multiple loci, various statistical methods have been developed for identifying genetic epistasis effects. Among these methods, logic regression (LR) is an intriguing approach incorporating tree-like structures. Various methods have built on the original LR to improve different aspects of the model. In this study, we review four variations of LR, namely Logic Feature Selection, Monte Carlo Logic Regression, Genetic Programming for Association Studies, and Modified Logic Regression-Gene Expression Programming, and investigate the performance of each method using simulated and real genotype data. We contrast these with another tree-like approach, namely Random Forests, and a Bayesian logistic regression with stochastic search variable selection.     

Stability and Durability of Intra- and Intersex Social Bonds of Captive Rhesus Macaques (Macaca mulatta)

Many social species maintain differentiated relationships with their group members. These social bonds may reflect short-term interactions satisfying immediate needs. Alternatively, individuals of some species may entertain stable and valuable bonds that last much longer than opportunistic interactions would predict. This claim is supported by recent research that revealed clear fitness benefits for long-lasting social bonds. Here, we investigated the stability and equitability of social relationships in captive rhesus macaques, measured using their proximity and grooming patterns over a 3-yr period. We show that, in general, proximity patterns of the whole group were stable over 3 yr. More specifically, each individual’s top two nonkin within and between sex relationships based on proximity were relatively stable and some of these relationships lasted the full 3 yr. Female grooming relationships within and between sex were also stable over 3 yr. Moreover, strong social bonds in females were not based on age similarity and were not sex specific, suggesting that a general underlying mechanism of social bonding in female rhesus macaques. In contrast, patterns of male grooming of other males and of females were relatively unstable and male social bonds were less equitable than those of females. The differences in stability of the relationships between the sexes may reflect the dispersal pattern of rhesus macaques, although we have limited data on non-natal males in our study. With these data we add to a growing body of literature describing the value and durability of relationships among primates and other species.     

Preparation of an activated rhodopsin/transducin complex using a constitutively active mutant of rhodopsin

The interaction of rhodopsin and transducin has been the focus of study for more than 30 years, but only recently have efforts to purify an activated complex in detergent solution materialized. These efforts have used native rhodopsin isolated from bovine retina and employed either sucrose density gradient centrifugation or size exclusion chromatography to purify the complex. While there is general agreement on most properties of the activated complex, subunit stoichiometry is not yet settled, with rhodopsin/transducin molar ratios of both 2/1 and 1/1 reported. In this report, we introduce methods for preparation of the complex that include use of recombinant rhodopsin, so as to take advantage of mutations that confer constitutive activity and enhanced thermal stability on the protein, and immunoaffinity chromatography for purification of the complex. We show that chromatography on ConA-Sepharose can substitute for the immunoaffinity column and that bicelles can be used instead of detergent solution. We demonstrate the following: that rhodopsin has a covalently bound all-trans-retinal chromophore and therefore corresponds to the active metarhodopin II state; that transducin has an empty nucleotide-binding pocket; that the isolated complex is active and dissociates upon addition of guanine nucleotide; and finally that the stoichiometry corresponds reproducibly to a 1/1 molar ratio of rhodopsin to transducin.     

Patterns of Migration and Risks Associated with Leprosy among Migrants in Maranh?o,Brazil

Leprosy remains a public health problem in Brazil with new case incidence exceeding World Health Organization (WHO) goals in endemic clusters throughout the country. Migration can facilitate movement of disease between endemic and non-endemic areas, and has been considered a possible factor in continued leprosy incidence in Brazil. A study was conducted to investigate migration as a risk factor for leprosy. The study had three aims: (1) examine past five year migration as a risk factor for leprosy, (2) describe and compare geographic and temporal patterns of migration among past 5-year migrants with leprosy and a control group, and (3) examine social determinants of health associated with leprosy among past 5-year migrants. The study implemented a matched case-control design and analysis comparing individuals newly diagnosed with leprosy (n = 340) and a clinically unapparent control group (n = 340) without clinical signs of leprosy, matched for age, sex and location in four endemic municipalities in the state of Maranhão, northeastern Brazil. Fishers exact test was used to conduct bivariate analyses. A multivariate logistic regression analysis was employed to control for possible confounding variables. Eighty cases (23.5%) migrated 5-years prior to diagnosis, and 55 controls (16.2%) migrated 5-years prior to the corresponding case diagnosis. Past 5 year migration was found to be associated with leprosy (OR: 1.59; 95% CI 1.07–2.38; p = 0.02), and remained significantly associated with leprosy after controlling for leprosy contact in the family, household, and family/household contact. Poverty, as well as leprosy contact in the family, household and other leprosy contact, was associated with leprosy among past 5-year migrants in the bivariate analysis. Alcohol consumption was also associated with leprosy, a relevant risk factor in susceptibility to infection that should be explored in future research. Our findings provide insight into patterns of migration to localize focused control efforts in endemic areas with high population mobility.     

Why preen others? Predictors of allopreening in parrots and corvids and comparisons to grooming in great apes

Allogrooming in primates serves not only a hygienic function, but also plays a crucial role in maintaining strong affiliative bonds between group members, which in turn, underpin the emergence of cooperative behavior. In contrast, although allopreening occurs in many avian species, we know little about its social functions. Our study addresses this issue by investigating allopreening in a broad comparative data set including six corvid and nine parrot species. We assessed whether rates of allopreening initiations, proportion of time spent allopreening, and the number of grooming partners in captive group-housed birds were comparable to patterns observed in captive chimpanzees and bonobos. While parrots and corvids were found to have similar rates of social grooming to bonobos and chimpanzees, Pan species dedicated significantly more time to social grooming. Animals in larger groups had more grooming partners, but when controlling for the number of potential partners, birds tended to have fewer grooming interaction partners than Pan species. We then investigated whether allopreening in parrots and corvids was predicted by behavioral markers of affiliative social bonds (close physical proximity, active feeding, and low levels of agonistic behavior). Results revealed that providing allopreening to a partner was significantly predicted by often being in close proximity, but not engagement in active feeding or agonistic behavior. We examined the region allopreened in a subset of species and found that preening a partner's head was predicted by both close physical proximity and active feeding, while body allopreening was only predicted by close physical proximity. Head preening may confer more hygienic benefits to recipients, and thus, may be more selectively provided to valued partners. Results support the hypothesis that allopreening in corvids and parrots helps maintain social bonds with an individual's most important social partners, showing some similarities to allogrooming in primates.     

Improved bacteria detection by coupling magneto-immunocapture and amperometry at flow-channel microband electrodes

This paper describes the first immunosensing system reported for the detection of bacteria combining immunomagnetic capture and amperometric detection in a one-step sandwich format, and in a microfluidic environment. Detection is based on the electrochemical monitoring of the activity of horseradish peroxidase (HRP), an enzyme label, through its catalysis of hydrogen peroxide (H(2)O(2)) in the presence of the mediator hydroquinone (HQ). The enzymatic reaction takes place in an incubation micro-chamber where the magnetic particles (MPs) are confined, upstream from the working electrode. The enzyme product is then pumped along a microchannel, where it is amperometrically detected by a set of microelectrodes. This design avoids direct contact of the biocomponents with the electrode, which lowers the risk of electrode fouling. The whole assay can be completed in 1h. The experiments performed with Escherichia coli evidenced a linear response for concentrations ranging 10(2)-10(8) cell ml(-1), with a limit of detection of 55 cells ml(-1) in PBS, without pre-enrichment steps. Furthermore, 100 cells ml(-1) could be detected in milk, and with negligible interference by non-target bacteria such as Pseudomonas.     

A New β-Estradiol-lnducible Vector Set that Facilitates Easy Construction and Efficient Expression of Transgenes Reveals CBL3-Dependent Cytoplasm to Tonoplast Translocation of CIPK5

Transient and stable expression of transgenes is central to many investigations in plant biology research. Chemical regulation of expression can circumvent problems of plant lethality caused by constitutive overexpression or allow inducible knock （out/down） approaches. Several chemically inducible or repressible systems have been described and successfully applied. However, cloning and application-specific modification of most available inducible expression systems have been limited and remained complicated due to restricted cloning options. Here we describe a new set of 57 vectors that enable transgene expression in transiently or stably transformed cells. All vectors harbor a synthetically optimized XVE expression cassette, allowing I~-estradiol mediated protein expression. Plasmids are equipped with the reporter genes GUS, GFP, mCherry, or with HA and Strepll epitope tags and harbor an optimized multiple cloning site for flexible and simple clon- ing strategies. Moreover, the vector design allows simple substitution of the driving promoter to achieve tissue-specificity or to modulate expression ranges of inducible transgene expression. We report details of the kinetics and dose-dependence of expression induction in Arabidopsis leaf mesophyll protoplasts, transiently transformed Nicotiana benthamiana leaves, and stably transformed Arabidopsis plants. Using these vectors, we investigated the influence of CBL （Calcineurin B-like） protein expression on the subcellular localization of CIPKs （Calcineurin B-like interacting protein kinases）. These analyses uncovered that induced co-expression of CBL3 is fully sufficient for dynamic translocation of CIPK5 from the cytoplasm to the tonoplast. Thus, the vector system presented here facilitates a broad range of research applications.     

Targeting the RAF/MEK/ERK, PI3K/AKT and P53 pathways in hematopoietic drug resistance

We have presented data which documents the importance of the Raf>MEK>ERK and PI3K>Akt pathways in the development of drug resistance in hematopoietic cells. Further understanding of how these pathways interact and induce drug resistance could result in the identification of novel approaches to treat drug resistance in leukemia. Furthermore, p53 played a role in drug resistance in these cells as introduction of a DN-p53 construct increased the resistance of the cells to chemotherapeutic drugs. The drug-sensitive and drug-resistant FL/ΔAkt:ER+ΔRaf-1:AR cells will allow us the ability to determine not only which downstream components are induced by either Raf>MEK>ERK or PI3K>Akt that are necessary for proliferation and prevention of apoptosis, but also which components are important in drug resistance and how these two pathways can interact to influence drug resistance.