378 research outputs found

    Pride of flesh

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    afternoon of the writer

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    Little Caesar on TV

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    Zeptomole Electrochemical Detection of Metallothioneins

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    Thiol-rich peptides and proteins possess a large number of biological activities and may serve as markers for numerous health problems including cancer. Metallothionein (MT), a small molecular mass protein rich in cysteine, may be considered as one of the promising tumour markers. The aim of this paper was to employ chronopotentiometric stripping analysis (CPSA) for highly sensitive detection of MT.In this study, we used adsorptive transfer stripping technique coupled with CPSA for detection of cysteine, glutathione oxidized and reduced, phytochelatin, bovine serum albumin, and metallothionein. Under the optimal conditions, we were able to estimate detection limits down to tens of fg per ml. Further, this method was applied to detect metallothioneins in blood serum obtained from patients with breast cancer and in neuroblastoma cells resistant and sensitive to cisplatin in order to show the possible role of metallothioneins in carcinogenesis. It was found that MT level in blood serum was almost twice higher as compared to the level determined in healthy individuals.This paper brings unique results on the application of ultra-sensitive electroanalytical method for metallothionein detection. The detection limit and other analytical parameters are the best among the parameters of other techniques. In spite of the fact that the paper is mainly focused on metallothionein, it is worth mentioning that successful detection of other biologically important molecules is possible by this method. Coupling of this method with simple isolation methods such as antibody-modified paramagnetic particles may be implemented to lab-on-chip instrument

    A Review of Metallothionein Isoforms and their Role in Pathophysiology

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    The Metallothionein (MT) is a protein which has several interesting biological effects and has been demonstrated increase focus on the role of MT in various biological systems in the past three decades. The studies on the role of MT were limited with few areas like apoptosis and antioxidants in selected organs even fifty years after its discovery. Now acknowledge the exploration of various isoforms of MT such as MT-I, MT-II, MT-III and MT-IV and other isoforms in various biological systems

    A cellular model for studying accommodation to environmental stressors: Protection and potentiation by cadmium and other metals

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    Exposure of P. polycephalum to a subthreshold challenge of Cd2+, which did not delay mitosis, elicited a protective response against a mitotic delay resulting from subsequent exposure to a suprathreshold challenge of Cd2+. Some characteristics of this protective response are herein identified. The concentration of Cd2+ in the subthreshold challenge could be lowered to 10-5 m and maintain complete protection against a suprathreshold challenge of 5 x 10-4 m Cd2+. A subthreshold challenge of 10-4 m provided full protection against a Cd2+ concentration of 7 x 10-4 m. A subthreshold challenge of 10-4 m Cd2+ could be placed anywhere in the cell cycle approaching but not abutting a suprathreshold challenge of 5 x 10-4 m Cd2+ in late G2 and still provide complete protection with the exception of one point in early S. At that point, 10-4 m Cd2+ by itself was toxic to the cell; partial protection, however, developed. Other responses developed when metals were substituted for cadmium. Cd2+ protected against exposure to Hg2+ and Ni2+ but potentiated exposures to Co2+, Cu2+, Pb2+, or Zn2+. A curious observ ation is that exposure to Hg2+ and Ni2+ protected against exposure to Cd2+, while exposure to Co2+, Pb2+, or Zn2+ potentiated exposure to Cd2+. Hg2+ and Ni2+ protected against reexposure to themselves.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22746/1/0000301.pd

    EVER Proteins, Key Elements of the Natural Anti-Human Papillomavirus Barrier, Are Regulated upon T-Cell Activation

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    Human papillomaviruses (HPV) cause a variety of mucosal and skin lesions ranging from benign proliferations to invasive carcinomas. The clinical manifestations of infection are determined by host-related factors that define the natural anti-HPV barrier. Key elements of this barrier are the EVER1 and EVER2 proteins, as deficiency in either one of the EVER proteins leads to Epidermodysplasia Verruciformis (EV), a genodermatosis associated with HPV-induced skin carcinoma. Although EVERs have been shown to regulate zinc homeostasis in keratinocytes, their expression and function in other cell types that may participate to the anti-HPV barrier remain to be investigated. In this work, we demonstrate that EVER genes are expressed in different tissues, and most notably in lymphocytes. Interestingly, in contrast to the skin, where EVER2 transcripts are hardly detectable, EVER genes are both abundantly expressed in murine and human T cells. Activation of CD4+ and CD8+ T cells via the TCR triggers a rapid and profound decrease in EVER expression, accompanied by an accumulation of free Zn2+ ions. Thus, EVER proteins may be involved in the regulation of cellular zinc homeostasis in lymphocytes. Consistent with this hypothesis, we show that the concentration of Zn2+ ions is elevated in lymphoblastoid cells or primary T cells from EVER2-deficient patients. Interestingly, we also show that Zn2+ excess blocks T-cell activation and proliferation. Therefore, EVER proteins appear as key components of the activation-dependent regulation of Zn2+ concentration in T cells. However, the impact of EVER-deficiency in T cells on EV pathogenesis remains to be elucidated
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