Search results for "SORBENT"
showing 10 items of 635 documents
Bovine seminal ribonuclease is cytotoxic for both malignant and normal telomerase-positive cells
2005
Bovine seminal-ribonuclease (BS-RNase) is a member of the 'ribonucleases with special biological actions' family since it possesses specific anti-tumour, anti-spermatogenic and embryotoxic activities and exerts an immunosuppressive effect on T lymphocytes. In previous studies it was demonstrated that BS-RNase induced apoptosis in proliferating, malignant and normal cells and that telomerase activity loss also caused apoptotic death in neoplastic cells. Since an obvious relationship between cell proliferation and telomerase activity exists, the aim of this work was to study if the pro-apoptotic cytotoxic action exerted by BS-RNase on proliferating malignant cells (HT29) and proliferating nor…
Expression pattern of the urokinase-plasminogen activator system in rat DS-sarcoma: Role of oxygenation status and tumour size
2002
The urokinase plasminogen activator system plays a central role in malignant tumour progression. Both tumour hypoxia and enhancement of urokinase plasminogen activator, urokinase plasminogen activator-receptor and plasminogen activator inhibitor type 1 have been identified as adverse prognostic factors. Upregulation of urokinase plasminogen activator or plasminogen activator inhibitor type 1 could present means by which hypoxia influences malignant progression. Therefore, the impact of hypoxia on the expression pattern of the urokinase plasminogen activator system in rat DS-sarcoma in vivo and in vitro was examined. In the in vivo setting, tumour cells were implanted subcutaneously into rat…
Differences in Kaposi sarcoma-associated herpesvirus-specific and herpesvirus-non-specific immune responses in classic Kaposi sarcoma cases and match…
2011
Kaposi sarcoma (KS) might develop because of incompetent immune responses, both non-specifically and specifically against the KS-associated herpesvirus (KSHV). Peripheral blood mononuclear cells from 15 classic (non-AIDS) KS cases, 13 KSHV seropositives (without KS) and 15 KSHV-seronegative controls were tested for interferon-γ T-cell (enzyme-linked immunospot [Elispot]) responses to KSHV-latency-associated nuclear antigen (LANA), KSHV-K8.1 and CMV/Epstein-Barr virus (EBV) peptide pools. The forearm and thigh of each participant was also tested for delayed-type hypersensitivity (DTH) against common recall antigens. Groups were compared with Fisher exact test and multinomial logistic regress…
Antibody generation and immunoassay development in diverse formats for pyrimethanil specific and sensitive analysis
2012
Immunochemical techniques are complementary tools to modern analytical requirements. These methods rely on the production of immunoreagents with adequate binding properties. In the present study, a rationally designed and functionalized derivative of pyrimethanil-a modern anilinopyrimidine fungicide-was synthesized in order to generate for the first time high-affinity and selective antibodies to this xenobiotic. A single coupling procedure-based on hapten activation using N,N′-disuccinimidyl carbonate and purification of the active ester-was followed to prepare both immunizing and assay conjugates. Polyclonal antibodies were produced and characterized by enzyme-linked immunosorbent assay (E…
Solid-Phase Extraction and Clean-Up Procedures in Pharmaceutical Analysis
2012
Solid-phase extraction (SPE) using small cartridges filled with sorbents of a small particle size has rapidly established itself as an important sample clean-up technique. It has prospered at the expense of liquid-liquid extraction (LLE), which is considered labor intensive and frequently plagued by problems, such as emulsion formation and use of large volumes of hazardous solvents. A remarkable characteristic of SPE is its easy adaptation to on-line mode by column-switching techniques; switching can be effected manually or by automated controllers. The same analyte/sorbent interactions that are exploited in liquid chromatography (LC) are of use in SPE, but particle sizes employed are great…
Allogeneic effector/memory Th-1 cells impair FoxP3+ regulatory T lymphocytes and synergize with chaperone-rich cell lysate vaccine to treat leukemia
2011
AbstractTherapeutic strategies combining the induction of effective antitumor immunity with the inhibition of the mechanisms of tumor-induced immunosuppression represent a key objective in cancer immunotherapy. Herein we demonstrate that effector/memory CD4+ T helper-1 (Th-1) lymphocytes, in addition to polarizing type-1 antitumor immune responses, impair tumor-induced CD4+CD25+FoxP3+ regulatory T lymphocyte (Treg) immunosuppressive function in vitro and in vivo. Th-1 cells also inhibit the generation of FoxP3+ Tregs from naive CD4+CD25−FoxP3− T cells by an interferon-γ–dependent mechanism. In addition, in an aggressive mouse leukemia model (12B1), Th-1 lymphocytes act synergistically with …
mRNA-induction and cytokine release during in vitro exposure of human nasal respiratory epithelia to methyl methacrylate
2007
Abstract Background Methyl methacrylate (MMA) has been reported to cause histopathological changes in rodent nasal epithelium after inhalation challenges. Data in humans are lacking. Methods In this in vitro design 22 primary cell cultures taken from inferior turbinate tissue of healthy individuals were exposed to MMA concentrations of 50 ppm (German MAK-value) and 200 ppm. mRNA expression and cytokine release of inflammatory mediators were quantified after 4 h and after 24 h. Controls were exposed to synthetic air. Q-PCR analysis was performed for TNF-α, IL-1β, IL-6, IL-8, MCP-1, GMCSF, Cox-1 and Cox-2. ELISA assays were performed from culture supernatants for TNF-α, IL-1β, IL-6, IL-8, MCP…
Anti-inflammatory effects of chemically modified tetracyclines by the inhibition of nitric oxide and interleukin-12 synthesis in J774 cell line
2001
We investigated the effects of chemically modified tetracyclines (CMTs) on the production of nitric oxide (NO) and on the synthesis of some cytokines: tumour necrosis factor alpha (TNF-alpha), interleukin(IL)-10 and IL-12 in lipopolysaccharide (LPS)-treated J774 cell line. Furthermore, we studied the ability of these drugs to modify the viability in LPS-stimulated J774 macrophages. CMTs decreased, in a dose-dependent manner, inducible NO synthase (iNOS) activity and, consequently, nitrite formation in J774 cultures. The CMT-induced decrease in NO production is due to the inhibition of enzyme activity rather than to a direct effect on enzyme expression. The absence of the inhibition in mRNA …
Increased adhesion and activation of polymorphonuclear neutrophil granulocytes to endothelial cells under heavy metal exposure in vitro.
1994
Heavy metals have been implicated in the mechanisms of endothelial damage. Influences of heavy metal ions on diverse cell types have been studied using a variety of in vitro and in vivo methods. Polymorphonuclear neutrophil granulocytes (PMNs) have physiological and pathological functions, including the modulation of adhesion to and destruction of endothelial cells (ECs). PMNs were studied during interaction with human umbilical vein ECs under exposure to zinc, nickel and cobalt using an in vitro model. We studied adhesion processes with the help of a computer-controlled image-analyzing system and examined the activation of PMNs by quantification of leukotriene B4 (LTB4) release. The biphas…
Recombinant virus-like particles of a norovirus (genogroup II strain) administered intranasally and orally with mucosal adjuvants LT and LT(R192G) in…
2003
We investigated the immune response induced by mucosal immunization of BALB/c mice with virus-like particles (VLPs) of a genogroup II norovirus, Dijon171/96 virus, produced in the baculovirus system. VLPs administered alone by the intranasal route induced a high serum antibody response as well as fecal IgA, which were enhanced when the heat-labile Escherichia coli toxin or its non toxic mutant LT(R192G) was coadministered. In these conditions, the oral route was also efficient. Cytokine production by cells from different lymphoid tissues was then assessed after in vitro restimulation. A Th1/Th2-like response was observed in cervical lymph node and Peyer's patch (PP) cell cultures from mice …