Bacterial Deposition of Gold on Hair: Archeological,Forensic and Toxicological Implications

Background

Trace metal analyses in hair are used in archeological, forensic and toxicological investigations as proxies for metabolic processes. We show metallophilic bacteria mediating the deposition of gold (Au), used as tracer for microbial activity in hair post mortem after burial, affecting results of such analyses.

Methodology/Principal Findings

Human hair was incubated for up to six months in auriferous soils, in natural soil columns (Experiment 1), soils amended with mobile Au(III)-complexes (Experiment 2) and the Au-precipitating bacterium Cupriavidus metallidurans (Experiment 3), in peptone-meat-extract (PME) medium in a culture of C. metallidurans amended with Au(III)-complexes (Experiment 4), and in non-auriferous soil (Experiment 5). Hair samples were analyzed using scanning electron microscopy, confocal microscopy and inductively coupled plasma-mass spectrometry. In Experiments 1–4 the Au content increased with time (P = 0.038). The largest increase was observed in Experiment 4 vs. Experiment 1 (mean = 1188 vs. 161 µg Kg⁻¹, Fisher''s least significance 0.001). The sulfur content, a proxy for hair metabolism, remained unchanged. Notably, the ratios of Au-to-S increased with time (linear trend P = 0.02) and with added Au and bacteria (linear trend, P = 0.005), demonstrating that larger populations of Au-precipitating bacteria and increased availability of Au increased the deposition of Au on the hair.

Conclusion/Significance

Interactions of soil biota with hair post mortem may distort results of hair analyses, implying that metal content, microbial activities and the duration of burial must be considered in the interpretation of results of archeological, forensic and toxicological hair analyses, which have hitherto been proxies for pre-mortem metabolic processes.     

The socioeconomic conditions determining the development, persistence, and decline of forest garden systems

There is a range of forest management systems between pure extraction and plantation systems. Such “intermediate systems” range from wild forests modified for increased production of selected products to anthropogenic forests with a high-density of valuable species growing within a relatively diverse and complex structure. These systems, classed here as “Forest Garden Systems” (FGS), have important socioeconomic and ecological benefits, and yet they have been largely overlooked by researchers, development practitioners, and policy makers. Based on case examples and the authors’ experience, this paper analyzes the socioeconomic and institutional factors that explain the development, persistence, and decline of FGS. These systems combine productivity and biodiversity values and are important components in the diverse economic systems of their managers. As such, the model warrants increased attention to protect existing values, to support the adaptation of existing systems to changing circumstances, and to inform the development of new models of integrated forest management     

Characterization of mono- and diaminopyrimidine derivatives as novel,nonpeptide gonadotropin releasing hormone (GnRH) receptor antagonists

A novel series of derivatives of mono- and diaminopyrimidines 1 potently displaced binding of a radiolabeled GnRH analogue to human and rat GnRH receptors. Analogues from these series competitively antagonized GnRH-stimulated increases in extracellular acidification in vitro and suppressed GnRH-mediated increases in circulating luteinizing hormone (LH) in castrated rats and testosterone in intact rats. These compounds or their analogues may be useful in treating sex hormone-dependent disease.     

Viral Proteinase Requirements for the Nucleocytoplasmic Relocalization of Cellular Splicing Factor SRp20 during Picornavirus Infections

Infection of mammalian cells by picornaviruses results in the nucleocytoplasmic redistribution of certain host cell proteins. These viruses interfere with import-export pathways, allowing for the cytoplasmic accumulation of nuclear proteins that are then available to function in viral processes. We recently described the cytoplasmic relocalization of cellular splicing factor SRp20 during poliovirus infection. SRp20 is an important internal ribosome entry site (IRES) trans-acting factor (ITAF) for poliovirus IRES-mediated translation; however, it is not known whether other picornaviruses utilize SRp20 as an ITAF and direct its cytoplasmic relocalization. Also, the mechanism by which poliovirus directs the accumulation of SRp20 in the cytoplasm of the infected cell is currently unknown. Work described in this report demonstrated that infection by another picornavirus (coxsackievirus B3) causes SRp20 to relocalize from the nucleus to the cytoplasm of HeLa cells, similar to poliovirus infection; however, SRp20 is relocalized to a somewhat lesser extent in the cytoplasm of HeLa cells during infection by yet another picornavirus (human rhinovirus 16). We show that expression of poliovirus 2A proteinase is sufficient to cause the nucleocytoplasmic redistribution of SRp20. Following expression of poliovirus 2A proteinase in HeLa cells, we detect cleavage of specific nuclear pore proteins known to be cleaved during poliovirus infection. We also find that expression of human rhinovirus 16 2A proteinase alone can cause efficient cytoplasmic relocalization of SRp20, despite the lower levels of SRp20 relocalization observed during rhinovirus infection compared to poliovirus. Taken together, these results further define the mechanism of SRp20 cellular redistribution during picornavirus infections, and they provide additional insight into some of the differences observed between human rhinovirus and other enterovirus infections.     

Wireless platform for controlled nitric oxide releasing optical fibers for mediating biological response to implanted devices

Despite the documented potential to leverage nitric oxide generation to improve in vivo performance of implanted devices, a key limitation to current NO releasing materials tested thus far is that there has not been a means to modulate the level of NO release after it has been initiated. We report the fabrication of a wireless platform that uses light to release NO from a polymethylmethacrylate (PMMA) optical fiber coated with an S-nitroso-N-acetylpenicillamine derivatized polydimethylsiloxane (SNAP-PDMS). We demonstrate that a VAOL-5GSBY4 LED (λ(dominant)=460nm) can be used as a dynamic trigger to vary the level of NO released from 500μm diameter coated PMMA. The ability to generate programmable sequences of NO flux from the surface of these coated fibers offers precise spatial and temporal control over NO release and provides a platform to begin the systematic study of in vivo physiological response to implanted devices. NO surface fluxes up to 3.88±0.57×10(-10)molcm(-2)min(-1) were achieved with ～100μm thick coatings on the fibers and NO flux was pulsed, ramped and held steady using the wireless platform developed. We demonstrate the NO release is linearly proportional to the drive current applied to the LED (and therefore level of light produced from the LED). This system allow the surface flux of NO from the fibers to be continuously changed, providing a means to determine the level and duration of NO needed to mediate physiological response to blood contacting and subcutaneous implants and will ultimately lead to the intelligent design of NO releasing materials tailored to specific patterns of NO release needed to achieve reliable in vivo performance for intravascular and subcutaneous sensors and potentially for a wide variety of other implanted biomedical devices.     

Role of ADAM and ADAMTS metalloproteinases in airway diseases

Lungs are exposed to the outside environment and therefore to toxic and infectious agents or allergens. This may lead to permanent activation of innate immune response elements. A Disintegrin And Metalloproteinases (ADAMs) and ADAMs with Thrombospondin motifs (ADAMTS) are proteinases closely related to Matrix Metalloproteinases (MMPs). These multifaceted molecules bear metalloproteinase and disintegrin domains endowing them with features of both proteinases and adhesion molecules. Proteinases of the ADAM family are associated to various physiological and pathological processes and display a wide spectrum of biological effects encompassing cell fusion, cell adhesion, "shedding process", cleavage of various substrates from the extracellular matrix, growth factors or cytokines... This review will focus on the putative roles of ADAM/ADAMTS proteinases in airway diseases such as asthma and COPD.     

The mechanism-based inactivation of 2,3-dihydroxybiphenyl 1,2-dioxygenase by catecholic substrates.

2,3-Dihydroxybiphenyl 1,2-dioxygenase (EC ), the extradiol dioxygenase of the biphenyl biodegradation pathway, is subject to inactivation during the steady-state cleavage of catechols. Detailed analysis revealed that this inactivation was similar to the O(2)-dependent inactivation of the enzyme in the absence of catecholic substrate, resulting in oxidation of the active site Fe(II) to Fe(III). Interestingly, the catecholic substrate not only increased the reactivity of the enzyme with O(2) to promote ring cleavage but also increased the rate of O(2)-dependent inactivation. Thus, in air-saturated buffer, the apparent rate constant of inactivation of the free enzyme was (0.7 +/- 0.1) x 10(-3) s(-1) versus (3.7 +/- 0.4) x 10(-3) s(-1) for 2,3-dihydroxybiphenyl, the preferred catecholic substrate of the enzyme, and (501 +/- 19) x 10(-3) s(-1) for 3-chlorocatechol, a potent inactivator of 2,3-dihydroxybiphenyl 1,2-dioxygenase (partition coefficient = 8 +/- 2, K(m)(app) = 4.8 +/- 0.7 microm). The 2,3-dihydroxybiphenyl 1,2-dioxygenase-catalyzed cleavage of 3-chlorocatechol yielded predominantly 2-pyrone-6-carboxylic acid and 2-hydroxymuconic acid, consistent with the transient formation of an acyl chloride. However, the enzyme was not covalently modified by this acyl chloride in vitro or in vivo. The study suggests a general mechanism for the inactivation of extradiol dioxygenases during catalytic turnover involving the dissociation of superoxide from the enzyme-catecholic-dioxygen ternary complex and is consistent with the catalytic mechanism.     

Characterization and partial purification of a substance in the pineal gland which inhibits cell multiplication in vitro

A substance which inhibits the in vitro multiplication of 3 cell strains, 37 RC, KB and NCTC clone 929, was characterized in the sheep pineal gland and partially purified using three successive chromatography techniques, respectively on Sephadex G-25, CM-cellulose and Biogel P 60 columms. The sheep cerebral cortex and liver also contain, but at much lower concentration than in the pineal, substance(s) that behave in different tests like the factor isolated from the pineal. The nature of the antimitotic substance from the pineal is as yet unknown. It is not destroyed by treatment with proteolytic enzymes, nor by boiling with 6 M HCl. It was established that it is different from the known antiblastic drugs such as Daunomycin and Methotrexate and from some active substances known to be present in the pineal, such as melatonin, serotonin and norepinephrine, which, in the same conditions, did not show any antimitotic activity. It was shown that when the concentration of the pineal factor in the culture medium was high enough (10 μg/ml), the inhibition of the KB cells multiplication was complete and irreversible. Microscopic examination of the treated cells showed that the morphological alteration was rapid (3–6 h) and deep, with shrinkage of both cytoplasm and nucleus, while the with antiblastic drugs, morphological alteration proceeded slower (1–3 days) and appeared less pronounced.