114 research outputs found

    Optimized intermolecular potential for nitriles based on Anisotropic United Atoms model

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    An extension of the Anisotropic United Atoms intermolecular potential model is proposed for nitriles. The electrostatic part of the intermolecular potential is calculated using atomic charges obtained by a simple Mulliken population analysis. The repulsion-dispersion interaction parameters for methyl and methylene groups are taken from transferable AUA4 literature parameters [Ungerer et al., J. Chem. Phys., 2000, 112, 5499]. Non-bonding Lennard-Jones intermolecular potential parameters are regressed for the carbon and nitrogen atoms of the nitrile group (–C≡N) from experimental vapor-liquid equilibrium data of acetonitrile. Gibbs Ensemble Monte Carlo simulations and experimental data agreement is very good for acetonitrile, and better than previous molecular potential proposed by Hloucha et al. [J. Chem. Phys., 2000, 113, 5401]. The transferability of the resulting potential is then successfully tested, without any further readjustment, to predict vapor-liquid phase equilibrium of propionitrile and n-butyronitrile

    G1 checkpoint protein and p53 abnormalities occur in most invasive transitional cell carcinomas of the urinary bladder

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    The G1 cell cycle checkpoint regulates entry into S phase for normal cells. Components of the G1 checkpoint, including retinoblastoma (Rb) protein, cyclin D1 and p16INK4a, are commonly altered in human malignancies, abrogating cell cycle control. Using immunohistochemistry, we examined 79 invasive transitional cell carcinomas of the urinary bladder treated by cystectomy, for loss of Rb or p16INK4a protein and for cyclin D1 overexpression. As p53 is also involved in cell cycle control, its expression was studied as well. Rb protein loss occurred in 23/79 cases (29%); it was inversely correlated with loss of p16INK4a, which occurred in 15/79 cases (19%). One biphenotypic case, with Rb+p16– and Rb-p16+ areas, was identified as well. Cyclin D1 was overexpressed in 21/79 carcinomas (27%), all of which retained Rb protein. Fifty of 79 tumours (63%) showed aberrant accumulation of p53 protein; p53 staining did not correlate with Rb, p16INK4a, or cyclin D1 status. Overall, 70% of bladder carcinomas showed abnormalities in one or more of the intrinsic proteins of the G1 checkpoint (Rb, p16INK4a and cyclin D1). Only 15% of all bladder carcinomas (12/79) showed a normal phenotype for all four proteins. In a multivariate survival analysis, cyclin D1 overexpression was linked to less aggressive disease and relatively favourable outcome. In our series, Rb, p16INK4a and p53 status did not reach statistical significance as prognostic factors. In conclusion, G1 restriction point defects can be identified in the majority of bladder carcinomas. Our findings support the hypothesis that cyclin D1 and p16INK4a can cooperate to dysregulate the cell cycle, but that loss of Rb protein abolishes the G1 checkpoint completely, removing any selective advantage for cells that alter additional cell cycle proteins. © 1999 Cancer Research Campaig

    Non-Neoplastic and Neoplastic Pleural Endpoints Following Fiber Exposure

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    Exposure to asbestos fibers is associated with non-neoplastic pleural diseases including plaques, fibrosis, and benign effusions, as well as with diffuse malignant pleural mesothelioma. Translocation and retention of fibers are fundamental processes in understanding the interactions between the dose and dimensions of fibers retained at this anatomic site and the subsequent pathological reactions. The initial interaction of fibers with target cells in the pleura has been studied in cellular models in vitro and in experimental studies in vivo. The proposed biological mechanisms responsible for non-neoplastic and neoplastic pleural diseases and the physical and chemical properties of asbestos fibers relevant to these mechanisms are critically reviewed. Understanding mechanisms of asbestos fiber toxicity may help us anticipate the problems from future exposures both to asbestos and to novel fibrous materials such as nanotubes. Gaps in our understanding have been outlined as guides for future research

    Protein p16 as a marker of dysplastic and neoplastic alterations in cervical epithelial cells

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    BACKGROUND: Cervical carcinomas are second most frequent type of women cancer. Success in diagnostics of this disease is due to the use of Pap-test (cytological smear analysis). However Pap-test gives significant portion of both false-positive and false-negative conclusions. Amendments of the diagnostic procedure are desirable. Aetiological role of papillomaviruses in cervical cancer is established while the role of cellular gene alterations in the course of tumor progression is less clear. Several research groups including us have recently named the protein p16(INK4a )as a possible diagnostic marker of cervical cancer. To evaluate whether the specificity of p16(INK4a )expression in dysplastic and neoplastic cervical epithelium is sufficient for such application we undertook a broader immunochistochemical registration of this protein with a highly p16(INK4a)-specific monoclonal antibody. METHODS: Paraffin-embedded samples of diagnostic biopsies and surgical materials were used. Control group included vaginal smears of healthy women and biopsy samples from patients with cervical ectopia. We examined 197 samples in total. Monoclonal antibody E6H4 (MTM Laboratories, Germany) was used. RESULTS: In control samples we did not find any p16(INK4a)-positive cells. Overexpression of p16(INK4a )was detected in samples of cervical dysplasia (CINs) and carcinomas. The portion of p16(INK4a)-positive samples increased in the row: CIN I – CIN II – CIN III – invasive carcinoma. For all stages the samples were found to be heterogeneous with respect to p16(INK4a)-expression. Every third of CINs III and one invasive squamous cell carcinoma (out of 21 analyzed) were negative. CONCLUSIONS: Overexpression of the protein p16(INK4a )is typical for dysplastic and neoplastic epithelium of cervix uteri. However p16(INK4a)-negative CINs and carcinomas do exist. All stages of CINs and carcinomas analyzed are heterogeneous with respect to p16(INK4a )expression. So p16(INK4a)-negativity is not a sufficient reason to exclude a patient from the high risk group. As far as normal cervical epithelium is p16(INK4a)-negative and the ratio p16(INK4a)-positive/ p16(INK4a)-negative samples increases at the advanced stages application of immunohisto-/cytochemical test for p16(INK4a )may be regarded as a supplementary test for early diagnostics of cervical cancer

    Oncolytic measles viruses encoding interferon β and the thyroidal sodium iodide symporter gene for mesothelioma virotherapy

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    Mesothelioma usually leads to death within 8–14 months of diagnosis. To increase the potency of oncolytic measles viruses (MVs) for mesothelioma therapy, we inserted the interferon β (IFNβ) gene alone or with the human thyroidal sodium iodide symporter (NIS) gene into attenuated MV of the Edmonston lineage. The corresponding mouse IFNβ (mIFNβ) viruses, MV-mIFNβ and MV-mIFNβ-NIS, successfully propagated in human mesothelioma cells, leading to intercellular fusion and cell death. High levels of mIFNβ were detected in the supernatants of the infected cells, and radioiodine uptake was substantial in the cells infected with MV-mIFNβ-NIS. MV with mIFNβ expression triggered CD68-positive immune cell infiltration 2–4 times higher than MV-GFP injected into the tumor site. The numbers of CD31-positive vascular endothelial cells within the tumor were decreased at day 7 after intratumoral injection of MV-mIFNβ or MV-mIFNβ-NIS, but not after MV-GFP and PBS administration. Immunohistochemical analysis showed that MV-mIFNβ changed the microenvironment of the mesothelioma by increasing innate immune cell infiltration and inhibiting tumor angiogenesis. Oncolytic MVs coding for IFNβ effectively retarded growth of human mesotheliomas and prolonged survival time in several mesothelioma tumor models. The results suggest that oncolytic MVs that code for IFNβ and NIS will be potent and versatile agents for the treatment of human mesothelioma

    Phase I study of bortezomib and cetuximab in patients with solid tumours expressing epidermal growth factor receptor

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    Bortezomib inhibits nuclear factor-κB (NF-κB). Cetuximab is a chimeric mouse–human antibody targeted against epidermal growth factor receptor (EGFR). We hypothesised that concomitant blockade of NF-κB and EGFR signalling would overcome EGFR-mediated resistance to single-agent bortezomib and induce apoptosis through two molecular pathways. The aim of this phase I trial was to establish the maximum tolerated dose (MTD) for bortezomib plus cetuximab in patients with EGFR-expressing epithelial tumours. The 21-day treatment cycle consisted of bortezomib administered on days 1 and 8 through dose escalation (1.3–2 mg m−2). Cetuximab was delivered at a dose of 250 mg m−2 on days 1, 8 and 15 (400 mg m−2 day 1 cycle 1). A total of 37 patients were enroled and given a total 91 cycles. No grade ⩾3 haematological toxicity was noted. Non-hematological grade ⩾3 toxicities included fatigue (22% of patients), dyspnoea (16%) and infection (11%). The MTD was not reached at the highest tested bortezomib dose (2.0 mg m−2). Efficacy outcomes included disease progression in 21 patients (56.7%) and stable disease (SD) at 6 weeks in 16 patients (43.3%). Five of the six patients with SD at 12 weeks were diagnosed with cancers of the lungs or head and neck. This combination therapy was moderately effective in extensively pretreated patients with non-small cell lung or head and neck cancers and warrants further investigation

    The Smiling Abbot: Rediscovering a Unique Medieval Effigial Slab

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Archaeological Journal on 06/11/2017, available online: http://www.tandfonline.com/doi/full/10.1080/00665983.2017.1366705The article reports on a newly re-discovered fragment of a recumbent effigial slab commemorating Abbot Hywel (‘Howel’), most likely an abbot of the Cistercian house of Valle Crucis, near Llangollen (Denbighs.). The slab was probably carved very early in the fourteenth century, and could have covered the abbot’s burial place. The stone was dislocated and fragmented at an unknown point in the abbey’s history, and most likely removed from the site during the nineteenth-century clearance of the abbey ruins. It was briefly reported on in 1895 and has been lost to scholarship subsequently. If indeed from Valle Crucis, the stone is the only known effigial slab commemorating a Cistercian abbot from Wales, and a rare example from Britain. Given that few similar Cistercian abbatial monuments have been identified from elsewhere, the ‘Smiling Abbot’, although only a fragment, is a significant addition to the known corpus of later medieval mortuary monuments. The article discusses the provenance, dating, identification and significance of the monument, including the abbot’s distinctive smile. The stone sheds new light on mortuary and commemorative practice at Valle Crucis Abbey in the early fourteenth century
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