6 research outputs found

    Provenance, manufacturing and corrosion behavior of Ancient Hellenistic coins from Egypt

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    Some copper alloy coins of the Ptolemaic period from a private collection, providing valuable evidence for both archaeometric as well as materials science and corrosion studies, have been investigated. The coins were found in the ancient city of Bubastis, known as Tell Basta, in the Nile Delta, Egypt. The coins have been examined by optical microscopy for their metallurgical structure, analysed by X-ray fluorescence and Electron Dispersion Spectroscopy for their composition, and by X-ray diffraction for the characterisation of their corrosion products. An attempt has been made to remove part of their corrosion products by mild chemical cleaning procedures. In some areas the coins are heavily corroded by chlorides, however most of the inscriptions on the coins themselves are still decipherable. Assumptions are made on the coins provenance, the production period, the manufacturing technique and the burial environmental conditions

    Antigen glycosylation regulates efficacy of CAR T cells targeting CD19

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    While chimeric antigen receptor (CAR) T cells targeting CD19 can cure a subset of patients with B cell malignancies, most patients treated will not achieve durable remission. Identification of the mechanisms leading to failure is essential to broadening the efficacy of this promising platform. Several studies have demonstrated that disruption of CD19 genes and transcripts can lead to disease relapse after initial response; however, few other tumor-intrinsic drivers of CAR T cell failure have been reported. Here we identify expression of the Golgi-resident intramembrane protease Signal peptide peptidase-like 3 (SPPL3) in malignant B cells as a potent regulator of resistance to CAR therapy. Loss of SPPL3 results in hyperglycosylation of CD19, an alteration that directly inhibits CAR T cell effector function and suppresses anti-tumor cytotoxicity. Alternatively, over-expression of SPPL3 drives loss of CD19 protein, also enabling resistance. In this pre-clinical model these findings identify post-translational modification of CD19 as a mechanism of antigen escape from CAR T cell therapy

    Cultivable Anaerobic Microbiota of Severe Early Childhood Caries▿¶

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    Severe early childhood caries (ECC), while strongly associated with Streptococcus mutans using selective detection (culture, PCR), has also been associated with a widely diverse microbiota using molecular cloning approaches. The aim of this study was to evaluate the microbiota of severe ECC using anaerobic culture. The microbial composition of dental plaque from 42 severe ECC children was compared with that of 40 caries-free children. Bacterial samples were cultured anaerobically on blood and acid (pH 5) agars. Isolates were purified, and partial sequences for the 16S rRNA gene were obtained from 5,608 isolates. Sequence-based analysis of the 16S rRNA isolate libraries from blood and acid agars of severe ECC and caries-free children had >90% population coverage, with greater diversity occurring in the blood isolate library. Isolate sequences were compared with taxon sequences in the Human Oral Microbiome Database (HOMD), and 198 HOMD taxa were identified, including 45 previously uncultivated taxa, 29 extended HOMD taxa, and 45 potential novel groups. The major species associated with severe ECC included Streptococcus mutans, Scardovia wiggsiae, Veillonella parvula, Streptococcus cristatus, and Actinomyces gerensceriae. S. wiggsiae was significantly associated with severe ECC children in the presence and absence of S. mutans detection. We conclude that anaerobic culture detected as wide a diversity of species in ECC as that observed using cloning approaches. Culture coupled with 16S rRNA identification identified over 74 isolates for human oral taxa without previously cultivated representatives. The major caries-associated species were S. mutans and S. wiggsiae, the latter of which is a candidate as a newly recognized caries pathogen
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