Metagenomic analyses uncover the differential effect of azide treatment on bacterial community structure by enriching a specific Cyanobacteria present in a saline-alkaline environmental sample.

Treatment of environmental samples under field conditions may require the application of chemical preservatives, although their use sometimes produces changes in the microbial communities. Sodium azide, a commonly used preservative, is known to differentially affect the growth of bacteria. Application of azide and darkness incubation to Isabel soda lake water samples induced changes in the structure of the bacterial community, as assessed by partial 16S rRNA gene pyrosequencing. Untreated water samples (WU) were dominated by gammaproteobacterial sequences accounting for 86%, while in the azide-treated (WA) samples, this group was reduced to 33% abundance, and cyanobacteria-related sequences became dominant with 53%. Shotgun sequencing and genome recruitment analyses pointed to Halomonas campanensis strain LS21 (genome size 4.07 Mbp) and Synechococcus sp. RS9917 (2.58 Mbp) as the higher recruiting genomes from the sequence reads of WA and WU environmental libraries, respectively, covering nearly the complete genomes. Combined treatment of water samples with sodium azide and darkness has proven effective on the selective enrichment of a cyanobacterial group. This approach may allow the complete (or almost-complete) genome sequencing of Cyanobacteria from metagenomic DNA of different origins, and thus increasing the number of the underrepresented cyanobacterial genomes in the databases.

Novel polymeric microspheres: Synthesis, enzyme immobilization, antimutagenic activity, and antimicrobial evaluation against pathogenic microorganisms.

New polymeric microspheres containing azomethine (1a-1c and 2a-2c) were synthesized by condensation to compare the enzymatic properties of the enzyme glucose oxidase (GOx) and to investigate antimutagenic and antimicrobial activities. The polymeric microspheres were characterized by elemental analysis, infrared spectra (FT-IR), proton nuclear magnetic resonance spectra, thermal gravimetric analysis, and scanning electron microscopy analysis. The catalytic activity of the glucose oxidase enzyme follows Michaelis-Menten kinetics. Influence of temperature, reusability, and storage capacity of the free and immobilized glucose oxidase enzyme were investigated. It is determined that immobilized enzymes exhibit good storage stability and reusability. After immobilization of GOx in polymeric supports, the thermal stability of the enzyme increased and the maximum reaction rate (Vmax ) decreased. The activity of the immobilized enzymes was preserved even after 5 months. The antibacterial and antifungal activity of the polymeric microspheres were evaluated by well-diffusion method against some selected pathogenic microorganisms. The antimutagenic properties of all compounds were also examined against sodium azide in human lymphocyte cells by micronuclei and sister chromatid exchange tests.

Generation of Loss-of-Function Mutants for Wheat Rust Disease Resistance Gene Cloning.

One of the most important tools to identify and validate rust resistance gene function is by producing loss-of-function mutants. Mutants can be produced using irradiation, chemicals, and insertions. Among all the mutagens, ethyl methanesulfonate (EMS) and sodium azide are most favored because of the ease of use and generation of random point mutations in the genome. The mutants so produced facilitate the isolation, identification and cloning of rust resistance genes. In this chapter we describe a protocol for seed mutagenesis of wheat with EMS and sodium azide.

Next-generation airbags and the possibility of negative outcomes due to thoracic injury.

Airbags have been shown to decrease morbidity and mortality associated with motor vehicle accidents when used in conjunction with seat belts. Airbag deployment alone however, has recently been implicated as a cause of significant thoracic injuries to unrestrained drivers. Resulting injuries include major cardiovascular and pulmonary complications. Airbags provide safety to occupants of cars and reduce mortality by 25%-30%. When not used in accordance with international standards, however, they can cause serious injury. We searched online databases from 1970 to January 2013 and included 17 retrospective studies, 12 systematic review articles, 18 case reports, 5 prospective studies, 1 lab study, 3 cohort studies, and 1 meta-analysis. Outcomes included clinical/functional response, left ventricular remodelling, hospitalizations, and mortality. Physicians must maintain a high index of suspicion for injury when evaluating drivers who were not wearing seat belts when airbags deployed, regardless of the speed of the collision, because increased risk of thoracic injury with airbags has been described in the literature. Our review indicates that even new technology, specifically the side air bag, has been associated with a risk of thoracic injury. Considering that regulations are a driving force for airbag technology, further research and scrutiny by medical teams is needed to consider the effects of airbag technology advancements on morbidity and mortality rates of car accidents, to help in guiding further improvement, and to help lawmakers in implementing rules that protect the safety of occupants.

Methane biogenesis during sodium azide-induced chemical hypoxia in rats.

Previous studies demonstrated methane generation in aerobic cells. Our aims were to investigate the methanogenic features of sodium azide (NaN(3))-induced chemical hypoxia in the whole animal and to study the effects of l-α-glycerylphosphorylcholine (GPC) on endogenous methane production and inflammatory events as indicators of a NaN(3)-elicited mitochondrial dysfunction. Group 1 of Sprague-Dawley rats served as the sham-operated control; in group 2, the animals were treated with NaN(3) (14 mg·kg(-1)·day(-1) sc) for 8 days. In group 3, the chronic NaN(3) administration was supplemented with daily oral GPC treatment. Group 4 served as an oral antibiotic-treated control (rifaximin, 10 mg·kg(-1)·day(-1)) targeting the intestinal bacterial flora, while group 5 received this antibiotic in parallel with NaN(3) treatment. The whole body methane production of the rats was measured by means of a newly developed method based on photoacoustic spectroscopy, the microcirculation of the liver was observed by intravital videomicroscopy, and structural changes were assessed via in vivo fluorescent confocal laser-scanning microscopy. NaN(3) administration induced a significant inflammatory reaction and methane generation independently of the methanogenic flora. After 8 days, the hepatic microcirculation was disturbed and the ATP content was decreased, without major structural damage. Methane generation, the hepatic microcirculatory changes, and the increased tissue myeloperoxidase and xanthine oxidoreductase activities were reduced by GPC treatment. In conclusion, the results suggest that methane production in mammals is connected with hypoxic events associated with a mitochondrial dysfunction. GPC is protective against the inflammatory consequences of a hypoxic reaction that might involve cellular or mitochondrial methane generation.

A competitive co-cultivation assay for cancer drug specificity evaluation.

The identification of compounds that specifically inhibit or kill cancer cells without affecting cells from healthy tissues is very challenging but very important for reducing the side effects of current cancer therapies. Hence, there is an urgent need for improved assays allowing the selectivity of a given compound to be monitored directly. The authors present an assay system based on the competitive co-cultivation of an excess of cancer cells with a small fraction of noncancer human indicator cells generating a fluorescence signal. In the absence of a specific anticancer compound, the cancer cells outgrow the indicator cells and abolish the fluorescence signal. In contrast, the presence of specific anticancer drugs (such as Tyrphostin-AG1478 or PLX4720) results in the selective growth of the indicator cells, giving rise to a strong fluorescence signal. Furthermore, the authors show that the nonspecific cytotoxic compound sodium azide kills both cancer and noncancer cells, and no fluorescence signal is obtained. Hence, this assay system favors the selection of compounds that specifically target cancer cells and decreases the probability of selecting nonspecific cytotoxic molecules. Z factors of up to 0.85 were obtained, indicating an excellent assay that can be used for high-throughput screening.

Effects of incense smoke on human lymphocyte DNA.

Incense burning is common in Southeast Asia, where it is a traditional and ceremonial practice in deity worship and paying respect to ancestors. However, incense emissions are an important source of indoor air pollution in Asia, and may induce health problems to those exposed. In this in vitro study the effects of incense emissions on human DNA were investigated using the comet assay. Particulates in smoke from six kinds of incense were trapped in saline or ethanol and human lymphocytes were exposed under controlled conditions. Results showed that DNA damage, including strand breaks, was induced by both aqueous and ethanolic extracts of two samples. The ethanolic extract of one sample induced DNA damage, while no significant DNA damage was found in the remaining three samples. The mechanisms underlying DNA damage induced by incense emissions were also investigated. Catalase (CAT), sodium azide, and superoxide dismutase (SOD) were co-incubated with extract, which exerted significant DNA damaging effects. Results showed that CAT with or without SOD diminished DNA damage, whereas sodium azide did not seem able to reduce DNA damage. Data indicate there are potential adverse health effects of such exposure, particularly for temple workers.

Evidence for sodium azide as an artifact mediating the modulation of inducible nitric oxide synthase by C-reactive protein.

C-reactive protein (CRP) is an acute-phase protein identified as a cardiovascular risk marker. In recent years, an increasing number of studies have investigated the possible direct effects of CRP on the vasculature, using mainly commercial CRP. In the present work, a potential role for CRP as a modulator of inducible nitric oxide synthase (iNOS) induction was explored. Cultured human aortic vascular smooth muscle cells (HASMC) were stimulated for 18 hours with 10 ng/mL interleukin-1beta (IL-1beta), resulting in a marked increase of iNOS levels and NO production, as determined by Western blotting and nitrite measurement, respectively. Commercial CRP (1 to 100 microg/mL) concentration-dependently inhibited the effects elicited by IL-1beta. Unexpectedly, similar results were observed when the commercial CRP solution was replaced by the corresponding vehicle medium containing growing concentrations of sodium azide. The inhibitory effects of commercial CRP or vehicle medium were lost on sodium azide removal by dialysis. In conclusion, sodium azide from the commercial CRP solution, but not CRP itself, mainly accounts for the inhibitory effect on IL-1beta-evoked iNOS induction and NO release. Care should be taken before attributing any biologic role to commercial CRP containing sodium azide.

Effects of airbag deployment: lesions, epidemiology, and management.

Airbags are restraining safety devices, but their activation may sometimes induce injuries during road accidents. Rapid deceleration due to an impact causes the ignition of a sodium azide cartridge, which releases nitrogen gas to inflate the nylon rubber bag. Numerous high-temperature gases, sodium hydroxide, carbon dioxide, and various other metallic oxides are also released producing a corrosive alkaline aerosol. Cutaneous and extracutaneous injuries due to airbag deployment may occur. Cutaneous injuries are frequent, and consist of irritant dermatitis, and chemical and thermal burns. Furthermore, numerous kinds of traumatic lesions (abrasions, friction burns, and lacerations) may be observed. Extracutaneous damage may involve the eyes, ears, cardiovascular system, nerves, joints, and bones. The nature of airbag lesions, their frequency, and management are reported. Even though the majority of airbag lesions are minor and do not require hospitalization, correct diagnosis and the choice of the most suitable treatment are necessary.

Burn injuries resulting from (accidental) airbag inflation.

INTRODUCTION: Airbags are intended to minimize facial injuries, alone and when used in combination with seatbelts in high-velocity motor-vehicle accidents. They may occasionally perforate, resulting in the release of sodium azide or sodium hydroxide, which result in chemical burns when in contact with skin. The force of deployment may itself result in significant blunt trauma, and there is a temperature rise during the inflation causing thermal burns, possibly as a separate and unnecessary consequence of a relatively minor accident. METHOD: A case report is presented. The literature on such injuries was reviewed and the mechanism of airbag deployment commented. CONCLUSION: Alternative designs and mechanisms of linking the activation of the device to the velocity of travel or to add a switch which is activated when accessing a motorway are recommended.

Air bag injury and the dermatologist.

Most new car models have driver-side air bags and many also have passenger-side and side-impact air bags. Air bags are known to be dangerous to small children and may cause death, fractures, and cerebral spinal injury. However, the cutaneous manifestations of air bag injury are less well known. Additional potential air bag injuries include retinal damage and high-frequency hearing loss. The following case report illustrates significant burns from a low-impact air bag injury and reviews the pertinent literature.