251 research outputs found

    Adaptive response to low dose of EMS or MMS in human peripheral blood lymphocytes

    Get PDF
    Human peripheral blood lymphocytes stimulated in vitro for 6 hr were exposed to a low (conditioning) dose of ethyl methanesulfonate (EMS; 1.5 x 10(-4) M) or methyl methanesulfonate (MMS; 1.5 x 10(-5) M). After 6 hr, the cells were treated with a high (challenging) concentration of the same agent (1.5 x 10(-3) M EMS or 1.5 x 10(-4) M MMS). The cells that received both conditioning and challenging doses became less sensitive to the induction of sister chromatid exchanges (SCEs) than those which did not receive the pretreatment with EMS or MMS. They responded with lower frequencies of SCEs. This suggests that conditioning dose of EMS or MMS has offered the lymphocytes to have decreased SCEs. This led to the realization that pre-exposure of lymphocytes to low dose can cause the induction of repair activity. This is a clear indication of the existence of adaptive response induced by alkylating agents whether it is ethylating or methylating in human lymphocytes in vitro

    Stereochemistry of gabapentin and several derivatives: solid state conformations and solution equilibria

    Get PDF
    Gabapentin (1-(aminomethyl)cycloheaxaneacetic acid; Gpn) is a widely used anti-epileptic drug. The target site of action of Gpn remains controversial. Gpn can exist in two isomeric chair forms. The crystal structures of Gpn 1 and eight derivatives, Gpn hydrochloride 2, Gpn lactam 3, Boc-Gpn-OH 4, Ac-Gpn-OH 5, Piv- Gpn-OH 6, Tosyl-Gpn-OH 7, Boc-Gpn-OSu 8 and Boc-Gpn-NHMe 9, are described. The aminomethyl group occupies an axial position in 1, 3, 6 and 7, while it lies in an equatorial orientation in 2, 4, 5 and 8. The structure of Boc-Gpn-NHMe 9 reveals that the crystals contain both chair forms of the derivative in the ratio 0.7:0.3, favouring the aminomethyl group in an axial position. In all cases, the torsional angles about the Cα–Cβ (θ1) and Cβ–Cγ (θ2) bonds of the g-amino acid residue are characteristic of a gauche, gauche (g, g) conformation. In solution, NMR studies establish rapid conformational exchange, as anticipated, at room temperature. Low temperature NMR studies permit conformational freezing and determination of the freeenergy difference between the two 1,1-disubstituted cyclohexane conformers. The largest free-energy difference is observed in the free amino acid (0.38 kcal mol–1), with the most stable conformer having the aminomethyl group in the equatorial position. The free-energy difference between the two forms is significantly reduced in the protected derivatives, with almost equal populations observed in solution for the fully protected neutral derivatives, Boc-Gpn-NHMe and Gpn lactam

    Loss of chromosome Y leads to down regulation of KDM5D and KDM6C epigenetic modifiers in clear cell renal cell carcinoma

    Get PDF
    Recent genomic studies of sporadic clear cell renal cell carcinoma (ccRCC) have uncovered novel driver genes and pathways. Given the unequal incidence rates among men and women (male:female incidence ratio approaches 2:1), we compared the genome-wide distribution of the chromosomal abnormalities in both sexes. We observed a higher frequency for the somatic recurrent chromosomal copy number variations (CNVs) of autosomes in male subjects, whereas somatic loss of chromosome X was detected exclusively in female patients (17.1%). Furthermore, somatic loss of chromosome Y (LOY) was detected in about 40% of male subjects, while mosaic LOY was detected in DNA isolated from peripheral blood in 9.6% of them, and was the only recurrent CNV in constitutional DNA samples. LOY in constitutional DNA, but not in tumor DNA was associated with older age. Amongst Y-linked genes that were downregulated due to LOY, KDM5D and KDM6C epigenetic modifiers have functionally-similar X-linked homologs whose deficiency is involved in ccRCC progression. Our findings establish somatic LOY as a highly recurrent genetic defect in ccRCC that leads to downregulation of hitherto unsuspected epigenetic factors, and suggest that different mechanisms may underlie the somatic and mosaic LOY observed in tumors and peripheral blood, respectively

    Current Treatment and Outcomes Benchmark for Locally Advanced or Metastatic Urothelial Cancer From a Large UK-Based Single Centre

    Get PDF
    Objectives: To characterize treatment patterns and survival outcomes for patients with locally advanced or metastatic malignancy of the urothelial tract during a period immediately preceding the widespread use of immune checkpoint inhibitors in the UK. Patients and Methods: We retrospectively examined the electronic case notes of patients attending the Leeds Cancer Center, UK with locally advanced or metastatic urothelial carcinoma, receiving chemotherapy between January 2003 and March 2017. Patient characteristics, treatment patterns, and outcomes were collected. Summary and descriptive statistics were calculated for categorical and continuous variables as appropriate. The Kaplan–Meier method was used to estimate median survival and Cox regression proportional hazards model was used to explore relationships between clinical variables and outcome. Results: Two hundred and sixteen patients made up the study cohort, with a median age of 66 years (range: 35–83) and 72.7% being male. First-line treatment consisted of either a cisplatin- (44%) or carboplatin-based regimen (48%) in the majority of patients. Twenty seven percent of patients received a second-line of treatment (most commonly single-agent paclitaxel) following a first-line platinum containing regimen. Grade 4 neutropenia was observed in 19 and 27% of those treated with a first-line cisplatin- and carboplatin-based regimen, respectively. The median overall survival (mOS) of the study cohort was estimated to be 16.2 months (IQR: 10.6–28.3 months). Receipt by patients of cisplatin-based chemotherapy was associated with a longer mOS and this association persisted when survival analysis was adjusted for age, sex, performance status and presence of distant metastases. Conclusions: This study provides a useful benchmark for outcomes achieved in a real-world setting for patients with locally advanced or metastatic UC treated with chemotherapy in the immediate pre-immunotherapy era

    Negative phenotypic and genetic associations between copulation duration and longevity in male seed beetles

    Get PDF
    Reproduction can be costly and is predicted to trade-off against other characters. However, while these trade-offs are well documented for females, there has been less focus on aspects of male reproduction. Furthermore, those studies that have looked at males typically only investigate phenotypic associations, with the underlying genetics often ignored. Here, we report on phenotypic and genetic trade-offs in male reproductive effort in the seed beetle, Callosobruchus maculatus. We find that the duration of a male's first copulation is negatively associated with subsequent male survival, phenotypically and genetically. Our results are consistent with life-history theory and suggest that like females, males trade-off reproductive effort against longevity

    The BLEMAB European project: Muon radiography as an imaging tool in the industrial field

    Get PDF
    The European project called BLEMAB (BLast furnace stack density Estimation through on-line Muons ABsorption measurements), provides for the application of the muon radiography technique in the industrial environment. The project represents a non-invasive way of monitoring a blast furnace and in particular aims to study the geometric and density development of the so-called “cohesive zone”, which is important for the performance of the blast furnace itself. The installation of the detectors is expected in 2022 at the ArcelorMittal site in Bremen (Germany). This paper describes the status of the project, the experimental setup and the first results obtained with preliminary simulations. © 2022 Societa Italiana di Fisica. All rights reserved

    Immunohistochemical analysis of the mechanistic target of rapamycin and hypoxia signalling pathways in basal cell carcinoma and trichoepithelioma

    Get PDF
    Background: Basal cell carcinoma (BCC) is the most common cancer in Caucasians. Trichoepithelioma (TE) is a benign neoplasm that strongly resembles BCC. Both are hair follicle (HF) tumours. HFs are hypoxic microenvironments, therefore we hypothesized that hypoxia-induced signalling pathways could be involved in BCC and TE as they are in other human malignancies. Hypoxia-inducible factor 1 (HIF1) and mechanistic/mammalian target of rapamycin (mTOR) are key players in these pathways. Objectives: To determine whether HIF1/mTOR signalling is involved in BCC and TE. Methods: We used immunohistochemical staining of formalin-fixed paraffin-embedded BCC (n = 45) and TE (n = 35) samples to assess activity of HIF1, mTORC1 and their most important target genes. The percentage positive tumour cells was assessed manually in a semi-quantitative manner and categorized (0%, 80%). Results: Among 45 BCC and 35 TE examined, expression levels were respectively 81% and 57% (BNIP3), 73% and 75% (CAIX), 79% and 86% (GLUT1), 50% and 19% (HIF1 alpha), 89% and 88% (pAKT), 55% and 61% (pS6), 15% and 25% (pMTOR), 44% and 63% (PHD2) and 44% and 49% (VEGF-A). CAIX, Glut1 and PHD2 expression levels were significantly higher in TE when only samples with at least 80% expression were included. Conclusions: HIF and mTORC1 signalling seems active in both BCC and TE. There are no appreciable differences between the two with respect to pathway activity. At this moment immunohistochemical analyses of HIF, mTORC1 and their target genes does not provide a reliable diagnostic tool for the discrimination of BCC and TE

    Spheroid-plug model as a tool to study tumor development, angiogenesis, and heterogeneity in vivo

    Get PDF
    Subcutaneous injection of the tumor cell suspension is a simple and commonly used tool for studying tumor development in vivo. However, subcutaneous models poorly resemble tumor complexity due to the fast growth not reflecting the natural course. Here, we describe an application of the new spheroid-plug model to combine the simplicity of subcutaneous injection with improved resemblance to natural tumor progression. Spheroid-plug model relies on in vitro formation of tumor spheroids, followed by injection of single tumor spheroid subcutaneously in Matrigel matrix. In spheroid-plug model, tumors grow slower in comparison to tumors formed by injection of cell suspension as assessed by 3D ultrasonography (USG) and in vivo bioluminescence measurements. The slower tumor growth rate in spheroid-plug model is accompanied by reduced necrosis. The spheroid-plug model ensures increased and more stable vascularization of tumor than classical subcutaneous tumor model as demonstrated by 3D USG Power Doppler examination. Flow cytometry analysis showed that tumors formed from spheroids have enhanced infiltration of endothelial cells as well as hematopoietic and progenitor cells with stem cell phenotype (c-Kit+ and Sca-1+). They also contain more tumor cells expressing cancer stem cell marker CXCR4. Here, we show that spheroid-plug model allows investigating efficiency of anticancer drugs. Treatment of spheroid-plug tumors with known antiangiogenic agent axitinib decreased their size and viability. The antiangiogenic activity of axitinib was higher in spheroid-plug model than in classical model. Our results indicate that spheroid-plug model imitates natural tumor growth and can become a valuable tool for cancer research
    corecore