Mycobacterium szulgai identification by hsp65 gene sequencing in an HIV-positive patient with non-Hodgkin's lymphoma

Mycobacterium szulgai, described for the first time in 1972, is a rare human pathogen that mainly causes pulmonary non-tubercular mycobacteriosis. We report its isolation and identification from a bronchoalveolar lavage specimen by hsp65 gene sequencing analysis in an HIV-positive patient with non-Hodgkin's lymphoma.     

Sampling effects, noise, and photobleaching in temporal image correlation spectroscopy

We present an extensive investigation of the accuracy and precision of temporal image correlation spectroscopy (TICS). Using simulations of laser scanning microscopy image time series, we investigate the effect of spatiotemporal sampling, particle density, noise, sampling frequency, and photobleaching of fluorophores on the recovery of transport coefficients and number densities by TICS. We show that the recovery of transport coefficients is usually limited by spatial sampling, while the measurement of accurate number densities is restricted by background noise in an image series. We also demonstrate that photobleaching of the fluorophore causes a consistent overestimation of diffusion coefficients and flow rates, and a severe underestimation of number densities. We derive a bleaching correction equation that removes both of these biases when used to fit temporal autocorrelation functions, without increasing the number of fit parameters. Finally, we image the basal membrane of a CHO cell with EGFP/alpha-actinin, using two-photon microscopy, and analyze a subregion of this series using TICS and apply the bleaching correction. We show that the photobleaching correction can be determined simply by using the average image intensities from the time series, and we use the simulations to provide good estimates of the accuracy and precision of the number density and transport coefficients measured with TICS.     

Measurement of monomer-oligomer distributions via fluorescence moment image analysis

We present higher-order moment analysis of fluorescence intensity fluctuations from individual laser scanning microscopy images applied to study monomer-oligomer distributions. We demonstrate that the number densities and brightness ratios of a mixed population of monomers and oligomers can be determined by analyzing higher-order moments of the fluorescence intensity fluctuations from individual images for specific ranges of densities and particle brightness ratios. Computer simulations and experiments with fluorescent microspheres and cells were performed to illustrate the detection limits and accuracy of this statistical approach. The simulation results show that the concentration of the dimer or oligomer population should be less than or equal to the monomeric concentration for the method to provide accurate results, and that the upper density detection limit of the population of monomers is one order-of-magnitude higher than the concentration of the oligomers. We implemented this technique to resolve two populations of fluorescent microspheres with different brightness ratios and we also applied the moment-analysis method to examine the distribution of aggregation states of PDGF-beta receptors in human fibroblast cells. The method was able to resolve a tetrameric population of the PDGF-beta receptors relative to the background distribution of nonspecifically bound fluorophore.     

Characterization of microsatellite markers in mandarin orange (Citrus reticulata Blanco)

A dinucleotide-enriched genomic library was obtained from mandarin orange (Citrus reticulata Blanco). A subset of 101 positive clones was sequenced and primers were designed. The loci were screened for levels of variation using 26-29 wild mandarin oranges collected in Vietnam. Forty-three loci were polymorphic with the number of alleles ranging from two to 18. The observed heterozygosity (H(O) ) and expected heterozygosity (H(E) ) were from 0.03 to 0.96 and from 0.03 to 0.92, respectively.     

High-performance liquid chromatographic separation and identification of polyphenolic compounds from the infusion of Davilla elliptica St. Hill

The isolation of polyphenolic compounds from an infusion of the Brazilian plant Davilla elliptica (Dilleniaceae), used as tea by virtue of its digestive properties, is described. An improved preparative HPLC method was used in order to isolate pure polyphenols from the complex mixture. Liquid-liquid extraction and solid-phase extraction were employed to minimise the interference of polymeric compounds and to provide an enriched fraction of the compounds of interest. The identification of the isolated compounds was performed using analytical HPLC as well as direct injection electrospray ionisation ion trap tandem mass spectrometry (ESI-IT-MS/MS). The high flavonoid content suggests that D. elliptica may be a promising source of compounds to produce natural phytomedicines.     

Sensitive detection of malaria infection by third harmonic generation imaging

Malaria remains a major health concern worldwide, with 350-500 million cases reported annually in endemic countries. In this study, we report a novel and highly sensitive optical-based detection of malaria-infected blood cells by third harmonic generation (THG) imaging of hemozoin pigment that is naturally deposited by the parasite during its lifecycle. The THG signal from the hemozoin was greater than we have observed in any cell type with signal/noise ratios that reach 1000:1. This method allows a rapid and robust detection of early stage infections of blood cells. The immense nonlinear response of the intrinsic parasitic by-product pigments suggests that automated optical detection by THG could be used for sensitive and rapid screening of parasite infection in blood samples.     

Saponins and Phenolics of Yucca schidigera Roezl: Chemistry and Bioactivity

Yucca schidigera (Agavaceae) is one of the major commercial source of steroidal saponins. Two products of yucca are available on the market. These include dried and finely powdered logs (yucca powder) or mechanically pressed and thermally condensed juice (yucca extract). These products possess the GRAS label which allows their use as foaming agent in soft drink (root beer), pharmaceutical, cosmetic, food, and feeding-stuffs industries. The main application of yucca products is in animal nutrition, in particular as a feed additive to reduce ammonia and fecal odors in animal excreta. The positive effects of dietary supplementation with yucca products on the growth rates, feed efficiency, and health of livestock seem to be due not only to the saponin constituents but also to other constituents. These observations prompted us to investigate the phenolic constituents of Y. schidigera. This study led to the isolation of resveratrol, trans-3,3′,5,5′-tetrahydroxy-4′-methoxystilbene, the sprirobiflavonoid larixinol along with novel phenolic derivatives with very unusual spirostructures, named yuccaols A–E and yuccaone A. Taking into account the multifunctional activities of resveratrol and the novelty of yuccaols A–E, structurally related to resveratrol, a program aimed to evaluate for yucca phenolics some of the activities exerted by resveratrol has been carried out. This review describes the chemistry of yucca saponins and phenolics, summarizes the biological activities of yucca products and constituents and gives an account on the actual and potential applications of yucca products.     

Expression of rolB in apomictic Hieracium piloselloides Vill. causes ectopic meristems in planta and changes in ovule formation, where apomixis initiates at higher frequency

The effects of the Agrobacterium rhizogenes rolB oncogene on apomixis were examined in the facultative apomictic plant Hieracium piloselloides because the oncogene has been shown to alter plant growth, morphogenesis and cellular sensitivity to auxin. Introduction of rolB under the control of either its own promoter or the CaMV35S promoter induced ectopic meristem formation from the inflorescence, confirming in planta a meristem-inducing role for this oncogene previously observed only in tissue culture. These ectopic meristems formed vegetative rosettes and floral plant organs. Upon immersion in water these meristems generated roots, suggesting that meristem commitment towards the generation of a specific organ type is a separate and later event that is dependent upon the developmental context. Ovule identity and form was altered in ectopically induced florets in plants expressing the CaMV35S::rolB construct. In contrast to the ovules of untransformed apomictic plants, the sexual process ceased earlier, prior to meiosis, yet surprisingly, apomixis initiated from a greater number of cells, and embryos and endosperm continued to develop in the structurally altered ovules. The alternative possibilities that the effects on reproduction might result from rolB influencing cellular response to auxin, or from alterations in cell signaling caused by changes in ovule morphology that are induced because of the expression of the oncogene are discussed.