Combined approach to demonstrate acetylcholinesterase activity changes in the rat brain following tabun intoxication and its treatment

Reactivation effects of K203 and currently available oximes (obidoxime, HI-6) in combination with atropine on acetylcholinesterase activities in the brain parts of rats poisoned with tabun were studied. The activity was determined by quantitative histochemical and biochemical methods correlating between them very well. The tabun-induced changes in acetylcholinsterase activity as well as in reactivation potency of reactivators used were different in various parts of the brain. Pontomedullar area seems to be important for observed changes following tabun intoxication and its treatment. From the oximes studied, the reactivation effect of K203 was comparable with obidoxime; HI-6 was ineffective. Combination of bio- and histochemical methods allow fine differentiation among the action of different oximes following tabun poisoning.     

A clinically relevant orthotopic xenograft model of ependymoma that maintains the genomic signature of the primary tumor and preserves cancer stem cells in vivo

Limited availability of in vitro and in vivo model systems has hampered efforts to understand tumor biology and test novel therapies for ependymoma, the third most common malignant brain tumor that occurs in children. To develop clinically relevant animal models of ependymoma, we directly injected a fresh surgical specimen from a 9-year-old patient into the right cerebrum of RAG2/severe complex immune deficiency (SCID) mice. All five mice receiving the initial transplantation of the patient tumor developed intracerebral xenografts, which have since been serially subtransplanted in vivo in mouse brains for 4 generations and can be cryopreserved for long-term maintenance of tumorigenicity. The xenograft tumors shared nearly identical histopathological features with the original tumors, harbored 8 structural chromosomal abnormalities as detected with spectral karyotyping, maintained gene expression profiles resembling that of the original patient tumor with the preservation of multiple key genetic abnormalities commonly found in human ependymomas, and contained a small population (<2.2%) of CD133⁺ stem cells that can form neurospheres and display multipotent capabilities in vitro. The permanent cell line (BXD-1425EPN), which was derived from a passage II xenograft tumor and has been passaged in vitro more than 70 times, expressed similar differentiation markers of the xenograft tumors, maintained identical chromosomal abnormalities, and formed tumors in the brains of SCID mice. In conclusion, direct injection of primary ependymoma tumor cells played an important role in the generation of a clinically relevant mouse model IC-1425EPN and a novel cell line, BXD-1425EPN. This cell line and model will facilitate the biological studies and preclinical drug screenings for pediatric ependymomas.     

Long-term immunogenicity of the new Vero cell-derived, inactivated Japanese encephalitis virus vaccine IC51 Six and 12 month results of a multicenter follow-up phase 3 study

Japanese encephalitis (JE) is the most common viral encephalitis in Asia. IC51 is a new Vero cell-derived, inactivated JE virus vaccine with non-inferior immunogenicity (after 2 months) compared to the US-licensed vaccine JE-VAX (mouse brain-derived, inactivated) and with a more convenient (two injections instead of three) intramuscular dose schedule. Adult subjects from two studies were followed-up for comparative immunogenicity (JE-VAX) at 6 months and long-term immunogenicity of IC51 alone at 12 months. At 6 months, immunogenicity was higher with IC51 (seroconversion rate [SCR] 95%; geometric mean titer [GMT] 84) than with JE-VAX (SCR 74%; GMT 34). At 12 months, the SCR was 83% and the GMT (41) remained above the protective titer of 1:10. Most people immunized with IC51 will have protective neutralizing antibody levels for at least a year.     

The Solidification/Stabilization of Wastewater (From a Landfill Leachate) in Specially Designed Binders Based on Coal Ash

The aim of this study is to assess the possibility to solidify/stabilize a liquid waste from a municipal waste landfill using binders based on coal ash (fly ash and bottom ash) and specially designed cements for waste treatment (INERCEM). The leaching test proved that all cementitious systems are efficient for the solidification/stabilization of the studied wastes and can reduce the leaching potential of heavy metals present in both liquid waste and coal ash. Therefore, these wastes cease to be a source of environmental pollution. X-ray diffraction (XRD) and thermal complex analysis (DTA-TG) were used to assess the nature and amount of compounds formed in these cementitious systems during the hydration and hardening processes; ettringite, calcium silicate hydrates and CaCO₃ were the main compounds formed in these systems assessed by these methods. The microstructure of hardened specimens was assessed by scanning electronic microscopy (SEM); the presence of hydrate phases, at the surface of cenospheres present in fly ash, proved the high pozzolanic reactivity of this phase.     

Synthesis of High-Performance CSA Cements as Low Carbon OPC Alternative

Starting from natural raw materials, cements based calcium sulphoaluminate (CSA) clinkers have been successfully obtained as an eco-friendly alternative to ordinary Portland cement. CSA-based cements with ye’elimite as the main phase have been produced over the years and are widely used today. In this regard, the present paper considers the study of hydration processes for CSA pastes prepared with a water/cement ratio of 0.5 according to the EN-197 standard and their characterization by thermal analysis (DTA-TG), X-ray diffraction analysis (XRD), and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX). A mechanical strength of 60.9 MPa was the greatest achieved for mortars hardened for 28 days.     

The forgotten or underestimated relevance of biopharmaceutical-based assessments for the oral absorption studies of oxime reactivators

Introduction: The absorption, distribution, metabolism, excretion and toxicity (ADME(T)) of oxime reactivators have been assessed with respect to their polarity, a fundamental requirement for their specific mechanism of action in the intoxication with organophosphorous compounds. The limitations of the therapeutic outcome have been associated not only with the severity of intoxication and to particularities of the toxicants, but also to the reduced lipophilicity and consequent restricted permeability across biological barriers.

Areas covered: This article inventories the plethora of mnemotic rules developed throughout the years for defining chemical spaces where drugs share one or more structural and ADME(T) characteristics. Their applicability to oxime is analyzed, especially in relation to intestinal absorption and brain distribution. Other aspects of oximes for antidotal outcome are also reviewed.

Expert opinion: The drugability rules are not applicable to oxime reactivators, because the increase in lipophicity and consequent improved permeability across biological barrier comes together with amplified (neuro)toxicity and reduced reactivating capacity. The available data suggest a high solubility and reduced metabolism, assigning the quaternary oximes to the fourth class of Biopharmaceutical Classification Systems. Reliance upon oral absorption data for designing safe centrally acting oximes can be of potential value, with adequate characterization of uptake-influx transporters interplay.     

Monoclonal antibody specific for histone H1 phosphorylated by cyclin-dependent kinases: a novel immunohistochemical probe of proliferation and neoplasia.

Monoclonal antibody 12D11 (MAb 12D11) has been shown to bind histone H1 isolated from human placenta and other tissues but not histone H1 that has been digested with bacterial alkaline phosphatase. We show here that phosphorylation of phosphatase-treated histone H1 with cyclin dependent-kinase (CDK) restores binding by MAb 12D11. We conclude that MAb 12D11 selectively binds histone H1 that has been phosphorylated by CDKs, and we have investigated the use of MAb 12D11 as an immunohistochemical probe of CDK activity in situ. Previous immunofluorescence studies have revealed strong nuclear staining by MAb 12D11 in proliferating cultured cells and the absence of staining in terminally differentiated cells. Immunohistochemical staining of frozen and formalin-fixed, paraffin-embedded sections of benign tissues with MAb 12D11 was nuclear and confined to recognized foci of cell proliferation. In lymphoid germinal centers, MAb 12D11 preferentially stained large lymphoid cells with a relative lack of staining in small cleaved cells, contrasting with a lack of cell size discrimination observed with the monoclonal antibody proliferation probe, MIB-1. Tumor tissues displayed strong albeit heterogeneous staining of malignant cells by MAb 12D11, with little or no staining observed in surrounding nonneoplastic stromal cells. Differential staining by MAb 12D11 of invasive and in situ carcinoma suggest applications in prognostication. MAb 12D11 may also be useful in identification of tumors more likely to respond to therapeutic CDK inhibitors.