Preparation of Expanded Chitin Foams and their Use in the Removal of Aqueous Copper.

Chitin is an underexploited, naturally abundant, mechanically robust, and chemically resistant biopolymer. These qualities are desirable in an adsorbent, but chitin lacks the necessary specific surface area, and its modification involves specialized techniques and equipment. Herein is described a novel chemical procedure for expanding chitin flakes, derived from shrimp shell waste, into foams with higher surface area.

Meconium identifies high levels of metals in newborns from a mining community in the U.S.

Background: This pilot study was conducted to determine if we could identify intrauterine exposure to metals in meconium, as a measure of exposure for mother-child pairs living in proximity to a mining operation.

Objectives: We used meconium as a means to measure metal exposure in utero. We set out to quantify the exposure to selected metals that are currently being mined and also are found in the Superfund site in Butte, Montana, and to compare it to that of Columbia, South Carolina, US, where mining is not occurring.

Influence of Iron-Doped Apatite Nanoparticles on Viral Infection Examined in Bacterial Versus Algal Systems.

The Centers for Disease Control and Prevention have estimated that each year, two million people in the United States become infected with antibiotic-resistant bacteria, of which, approximately 23000 die as a direct result of these infections. Phage therapy, or the treatment of bacterial infection by specific, antagonistic viruses, provides one alternative to traditional antibiotics. Bacteriophages, or phages, are bacteria-specific viruses that possess biological traits that allow for not only the removal of bacterial infection, but also the evasion of bacterial resistance, which renders antibiotics ineffective.

Inhibition of mitochondrial respiration as a source of adaphostin-induced reactive oxygen species and cytotoxicity.

Adaphostin is a dihydroquinone derivative that is undergoing extensive preclinical testing as a potential anticancer drug. Previous studies have suggested that the generation of reactive oxygen species (ROS) plays a critical role in the cytotoxicity of this agent. In this study, we investigated the source of these ROS.

Nei deficient Escherichia coli are sensitive to chromate and accumulate the oxidized guanine lesion spiroiminodihydantoin.

Growth inhibition and oxidized guanine lesion formation were studied in a number of base excision repair (BER) deficient Escherichia coli (E. coli) following chromate exposure. The only BER deficient bacterial strain that demonstrated significant growth inhibition by chromate, in comparison to its matched wild-type cell line, was the Nei deficient (TK3D11).

Guanine-specific oxidation of double-stranded DNA by Cr(VI) and ascorbic acid forms spiroiminodihydantoin and 8-oxo-2'-deoxyguanosine.

7,8-dihydro-8-oxoguanine (8-oxoG) is thought to be a major lesion formed in DNA by oxidative attack at the nucleobase guanine. Recent studies have shown that 8-oxoG has a lower reduction potential than the parent guanine and is a hot spot for further oxidation. Spiroiminodihydantoin (Sp) has been identified as one of these further oxidation products.

Recognition of the oxidized lesions spiroiminodihydantoin and guanidinohydantoin in DNA by the mammalian base excision repair glycosylases NEIL1 and NEIL2.

8-Oxoguanine (8-oxoG) is an unstable mutagenic DNA lesion that is prone to further oxidation. High valent metals such as Cr(V) and Ir(IV) readily oxidize 8-oxoG to form guanidinohydantoin (Gh), its isomer iminoallantoin (Ia), and spiroiminodihydantoin (Sp). When present in DNA, these lesions show enhanced base misincorporation over the parent 8-oxoG lesion leading to G --> T and G --> C transversion mutations and polymerase arrest.