Determination of the efficacy of two building decontamination strategies by surface sampling with culture and quantitative PCR analysis

The efficacy of currently available decontamination strategies for the treatment of indoor furnishings contaminated with bioterrorism agents is poorly understood. Efficacy testing of decontamination products in a controlled environment is needed to ensure that effective methods are used to decontaminate domestic and workplace settings. An experimental room supplied with materials used in office furnishings (i.e., wood laminate, painted metal, and vinyl tile) was used with controlled dry aerosol releases of endospores of Bacillus atrophaeus ("Bacillus subtilis subsp. niger," also referred to as BG), a Bacillus anthracis surrogate. Studies were performed using two test products, a foam decontaminant and chlorine dioxide gas. Surface samples were collected pre- and posttreatment with three sampling methods and analyzed by culture and quantitative PCR (QPCR). Additional aerosol releases with environmental background present on the surface materials were also conducted to determine if there was any interference with decontamination or sample analysis. Culture results indicated that 10(5) to 10(6) CFU per sample were present on surfaces before decontamination. After decontamination with the foam, no culturable B. atrophaeus spores were detected. After decontamination with chlorine dioxide gas, no culturable B. atrophaeus was detected in 24 of 27 samples (89%). However, QPCR analysis showed that B. atrophaeus DNA was still present after decontamination with both methods. Environmental background material had no apparent effect on decontamination, but inhibition of the QPCR assay was observed. These results demonstrate the effectiveness of two decontamination methods and illustrate the utility of surface sampling and QPCR analysis for the evaluation of decontamination strategies.     

Elevated risk for MPNST in NF1 microdeletion patients

An NF1 microdeletion is the single most commonly reported mutation in individuals with neurofibromatosis type 1 (NF1). Individuals with an NF1 microdeletion have, as a group, more neurofibromas at a younger age than the group of all individuals with NF1. We report that NF1 microdeletion individuals additionally have a substantially higher lifetime risk for the development of malignant peripheral nerve sheath tumors than individuals with NF1 who do not have an NF1 microdeletion. This should be taken into account in the medical follow-up of individuals with an NF1 microdeletion.     

Design and characterization of enzymosomes with surface-exposed superoxide dismutase

Superoxide dismutase (SOD) was chemically modified by covalent linkage of fatty acid chains to the accessible epsilon-amino groups of the enzyme. This acylation method gave rise to a different enzyme entity (Ac-SOD) as evidenced by different physicochemical properties such as octanol/water partition coefficient and isoelectric point (pI) as compared to SOD. Ac-SOD was incorporated in conventional and long-circulating liposomes (LCL) and characterized in terms of incorporation efficiency, protein to lipid ratio (Prot/Lip), enzymatic activity retention and zeta potential. The observation that Ac-SOD liposomes present enzymatic activity on their external surface indicates that these formulations can act independent of rate and extent of enzyme release as required in case of SOD liposomes. The decrease of superficial charge of liposomal formulations containing Ac-SOD, as compared to SOD liposomes, may be related to the negatively charged enzyme molecules localized on the liposome surface. The comparative characterization of Ac-SOD and SOD liposomal formulations evidenced that the two enzyme forms differ substantially regarding their intraliposomal location: SOD tends to be localized in the internal aqueous spaces, whereas Ac-SOD is expected to be localized in the lipid bilayers of the liposomes, partially buried into the outer surface and exposed to the external medium. These liposomal structures with surface-exposed SOD were designated as Ac-SOD enzymosomes. The properties of these enzymosomes may influence the therapeutic effect, as the release of the enzyme from extravasated vesicles is no longer a necessary requirement for achieving dismutating activity within the inflamed target site.     

Proteomic analysis of the mouse liver mitochondrial inner membrane

Mitochondria play a crucial role in cellular homeostasis, which justifies the increasing interest in mapping the different components of these organelles. Here we have focused our study on the identification of proteins of the mitochondrial inner membrane (MIM). This membrane is of particular interest because, besides the well known components of the respiratory chain complexes, it contains several ion channels and many carrier proteins that certainly play a key role in mitochondrial function and, therefore, deserve to be identified at the molecular level. To achieve this goal we have used a novel approach combining the use of highly purified mouse liver mitochondrial inner membranes, extraction of membrane proteins with organic acid, and two-dimensional liquid chromatography coupled to tandem mass spectrometry. This procedure allowed us to identify 182 proteins that are involved in several biochemical processes, such as the electron transport machinery, the protein import machinery, protein synthesis, lipid metabolism, and ion or substrate transport. The full range of isoelectric point (3.9-12.5), molecular mass (6-527 kDa), and hydrophobicity values (up to 16 transmembrane predicted domains) were represented. In addition, of the 182 proteins found, 20 were unknown or had never previously been associated with the MIM. Overexpression of some of these proteins in mammalian cells confirmed their mitochondrial localization and resulted in severe remodeling of the mitochondrial network. This study provides the first proteome of the MIM and provides a basis for a more detailed study of the newly characterized proteins of this membrane.     

Dual regulation of neuronal morphogenesis by a delta-catenin-cortactin complex and Rho

Delta-catenin is a neuronal protein that contains 10 Armadillo motifs and binds to the juxtamembrane segment of classical cadherins. We report that delta-catenin interacts with cortactin in a tyrosine phosphorylation-dependent manner. This interaction occurs within a region of the delta-catenin sequence that is also essential for the neurite elongation effects. Src family kinases can phosphorylate delta-catenin and bind to delta-catenin through its polyproline tract. Under conditions when tyrosine phosphorylation is reduced, delta-catenin binds to cortactin and cells extend unbranched primary processes. Conversely, increasing tyrosine phosphorylation disrupts the delta-catenin-cortactin complex. When RhoA is inhibited, delta-catenin enhances the effects of Rho inhibition on branching. We conclude that delta-catenin contributes to setting a balance between neurite elongation and branching in the elaboration of a complex dendritic tree.     

Genital morphology and fertilization success in the dung beetle Onthophagus taurus: an example of sexually selected male genitalia

In animals with internal fertilization and promiscuous mating, male genitalia show rapid and divergent evolution. Three hypotheses have been suggested to explain the evolutionary processes responsible for genital evolution: the lock-and-key hypothesis, the pleiotropy hypothesis and the sexual-selection hypothesis. Here, we determine whether variation in male genital morphology influences fertilization success in the dung beetle Onthophagus taurus, as predicted by the sexual-selection hypothesis. Variation in four out of five genital sclerites of the endophallus influenced a male's fertilization success, supporting the general hypothesis that male genitalia can evolve under sexual selection. Furthermore, different genital sclerites were found to enhance first versus second male paternity, indicating that different sclerites serve offensive and defensive roles. Genital-trait variability was comparable to that in other species but was less variable than a non-genital sexually selected trait (head horns). We suggest that directional selection for genital elaboration may be countered by natural selection, which should favour genitalia of a size and shape necessary for efficient coupling and sperm transfer.     

Vitamin C prevents hyperbaric oxygen-induced growth retardation and lipid peroxidation and attenuates the oxidation-induced up-regulation of glutathione in guinea pigs

Hyperbaric oxygen therapy is used to treat various clinical conditions, but it also causes oxidative damage. The objectives of this study are to determine if increased vitamin C intake can prevent hyperbaric oxygen-induced damage and to determine interactions among vitamin C, glutathione and vitamin E in response to oxidative stress. The growth rates of unexposed guinea pigs fed 1.25 mg vitamin C/day were indistinguishable from that of guinea pigs fed 50 mg vitamin C/day. In contrast, hyperbaric oxygen exposure resulted in growth retardation in guinea pigs fed 1.25 mg vitamin C/day, but it had little effect on the growth rates of guinea pigs fed 50 mg vitamin C/day. Increased vitamin C intake also prevented hyperbaric oxygen-induced lipid peroxidation in the liver. In guinea pigs not exposed to hyperbaric oxygen, levels of vitamin C in tissues were closely related to vitamin C intake, but tissue levels of glutathione and vitamin E were not related to vitamin C intake. However, interactions between vitamin C and glutathione were observed upon chronic hyperbaric oxygen exposure. Chronic hyperbaric oxygen exposure resulted in >2-fold increases in the levels of glutathione in liver and lung of guinea pigs fed 1.25 mg vitamin C/day. In comparison, the oxidation-induced increases in glutathione were significantly attenuated in guinea pigs fed 50 mg vitamin C/day. These data show that increased intake of vitamin C can prevent or alleviate the hyperbaric oxygen-induced damage. The interactions between vitamin C and glutathione upon hyperbaric oxygen exposure indicate that there is a homeostatic regulation of antioxidant capacity in guinea pig tissues.