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Results 301 - 350 of 1283
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Bedard Karen - - 2004
Prior induction of an endoplasmic reticulum stress response has been associated with an increased tolerance to cellular toxins in in vitro systems, primarily involving renal and neuronal cells. Reactive intermediates are involved in toxicity in many tissues, therefore, we wished to determine if cytoprotection after induction of an endoplasmic reticulum ...
Timothy Jake - - 2004
OBJECTIVE: The current treatment of hydrocephalus using ventriculoperitoneal shunts and third ventriculostomies remains problematic. We revisited the concept of destruction of the choroid plexus for the treatment of hydrocephalus by using an immunotoxin-based technique to specifically destroy this tissue. This approach was based on the observation that, as an epithelial ...
Yonezawa T - - 2004
GPR40, which has recently been identified as a G-protein-coupled cell-surface receptor for long-chain fatty acids, was assessed in a human breast cancer cell line (MCF-7). We detected GPR40 mRNA by RT-PCR and found that oleate and linoleate, but not palmitate or stearate, caused an increase in cellular Ca(2+) concentrations, which ...
Ilver Dag - - 2004
Helicobacter pylori is the causative agent of peptic ulcer disease. A major virulence factor of H. pylori is VacA, a toxin that causes massive vacuolization of epithelial cell lines in vitro and gastric epithelial erosion in vivo. Although VacA is exported over the outer membrane and is released from the ...
Jedema Inge - - 2004
OBJECTIVE: Unresponsiveness to chemotherapy is a major problem in the treatment of leukemia, which can be caused by unresponsiveness of noncycling cells to cell cycle-dependent cytotoxic agents. Targeted toxins consisting of a targeting and activating cytokine (granulocyte-macrophage colony-stimulating factor [GM-CSF]) and diphtheria toxin (DT) can be used to overcome this ...
Santos A - - 2004
The cytocidal effect of Pichia membranifaciens killer toxin on Candida boidinii cells was studied. The halotolerant yeast P. membranifaciens CYC 1106 produces a unique 18 kDa killer toxin that exerts its killer activity against C. boidinii IGC 3430 only in the presence of NaCl. Metabolic events associated with the loss ...
Jablonowski Daniel - - 2004
Kluyveromyces lactis zymocin, a heterotrimeric toxin complex, imposes a G1 cell cycle block on Saccharomyces cerevisiae that requires the toxin-target (TOT) function of holo-Elongator, a six-subunit histone acetylase. Here, we demonstrate that Elongator is a phospho-complex. Phosphorylation of its largest subunit Tot1 (Elp1) is supported by Kti11, an Elongator-interactor essential ...
Carbonell Gleize Villela - - 2004
In the present work, in vitro assays were used to investigate the toxicity of Serratia marcescens cytotoxin in cultured Chinese hamster ovary (CHO) cells. The time necessary to detect cellular alterations such as the onset of apoptosis, the perturbation of mitochondrial function, and cytoskeletal changes was assessed. The internalization of ...
Banks M R - - 2004
BACKGROUND: Cholera toxin (CT) acts on intestinal epithelial cells both directly and indirectly via activation of a secretory neural reflex. The reflex may release acetylcholine as one of its final neurotransmitters. This opens up the possibility of a third mechanism of action for CT, namely a synergistic interaction between two ...
Ahuja Nidhi - - 2004
Cyclic AMP is a ubiquitous messenger that integrates many processes of the cell. Diverse families of adenylate cyclases and phosphodiesterases stringently regulate the intracellular concentration of cAMP. Any alteration in the cytosolic concentration of cAMP has a profound effect on the various processes of the cell. Disruption of these cellular ...
Rambow-Larsen Amy A - - 2004
Pertussis toxin is an AB(5) toxin comprised of protein subunits S1 through S5. The individual subunits are secreted by a Sec-dependent mechanism into the periplasm, where the toxin is assembled. The Ptl type IV secretion system mediates secretion of assembled toxin past the outer membrane. In this study, we examined ...
Teplova Vera - - 2004
In this study we have investigated the impact of differentiation of neuronal cells on their sensitivity to microbial toxins. We used the human neural crest-derived tumor cell line Paju, which can be induced to differentiation in vitro by treatment with phorbol 12-myristate 13-acetate. Addition of the highly toxic potassium ionophores ...
Sekino Takaomi - - 2004
Shiga toxins (Stxs, also referred to as verotoxins) were first described as a novel cytotoxic activity against Vero cells. In this study, we report the characterization of an Stx1-resistant (R-) stock of Vero cells. (1) When the susceptibility of R-Vero cells to Stx1 cytotoxicity was compared to that of Stx1-sensitive ...
Anichtchik Oleg V - - 2004
Dopaminergic deficiency in the brain of zebrafish was produced by systemic administration of two catecholaminergic neurotoxins, 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), and the neurochemical and behavioural changes were characterized. The levels of dopamine and noradrenaline decreased significantly after the injection of MPTP and 6-OHDA. Corresponding to these changes, fish exhibited ...
Thelestam M - - 2004
The cytolethal distending toxins (CDTs) constitute the most recently discovered family of bacterial protein toxins. CDTs are unique among bacterial toxins as they have the ability to induce DNA double strand breaks (DSBs) in both proliferating and nonproliferating cells, thereby causing irreversible cell cycle arrest or death of the target ...
Gregory Laurel - - 2004
Satratoxin-G (SG) is the major macrocyclic trichothecene mycotoxin produced by Stachybotrys chartarum (atra) and has been implicated as a cause of a number of animal and human health problems including pulmonary hemorrhage in infants. However, there is little understanding where this toxin is localized in the spores and mycelial fragments ...
Haug Gerd - - 2003
The Clostridium botulinum C2 toxin is the prototype of the family of binary actin-ADP-ribosylating toxins. C2 toxin is composed of two separated nonlinked proteins. The enzyme component C2I ADP-ribosylates actin in the cytosol of target cells. The binding/translocation component C2II mediates cell binding of the enzyme component and its translocation ...
Smith Alicia E - - 2003
For murine polyomavirus (Py), previous studies suggest the cellular target is a terminal alpha2,3-linked sialic acid. Here, we investigate the binding and uptake of mouse polyomavirus-like particles (PyVLP) derived from bacterially expressed VP1. We find that in fibroblast 3T6 cells, binding of PyVLP was substantially reduced by sialidase treatment, but ...
Sarret Philippe - - 2004
Amphiphysins are SH3 domain-containing proteins thought to function in clathrin-mediated endocytosis. To investigate the potential role of amphiphysin II in cellular trafficking of G protein-coupled somatostatin (SRIF) receptors, we generated an AtT-20 cell line stably overexpressing amphiphysin IIb, a splice variant that does not bind clathrin. Endocytosis of (125)I-[d-Trp(8)]SRIF was ...
Uzarski Rebecca L - - 2003
The trichothecene mycotoxins, Shiga toxins (STs), and ricin are potent translational inhibitors that exert diverse mechanisms of action but all have the capacity to induce death by apoptosis. Germinal centers containing actively dividing B cells are particularly sensitive to protein synthesis inhibition, and, of these, the immature B cell is ...
LI Ying-Zhang, ZHENG Xiao-Hua, ...
The different resistance of cotton (Gossypium hirsutum   L.) cultivars to crude toxin of Verticillium dahliae   (VD) was correlated with the activities of chitinase and β-1, 3-glucanase in callus cells. The activities of chitinase and β-1, 3-glucanase in the callus cells treated with the VD-toxin were increased to the ...
Essmann F - - 2003
Recent data suggest that alpha-toxin, the major hemolysin of Staphylococcus aureus, induces cell death via the classical apoptotic pathway. Here we demonstrate, however, that although zVAD-fmk or overexpression of Bcl-2 completely abrogated caspase activation and internucleosomal DNA fragmentation, they did not significantly affect alpha-toxin-induced death of Jurkat T or MCF-7 ...
Beal Dominic R - - 2003
The epithelial Madin Darby canine kidney (MDCK) cell line, Caucasian renal leiomyoblastoma (G-402) cells, human small airways epithelial (HSAE) cells, human bronchial epithelial (HBE) cells and human renal proximal tubule (HRPT) epithelial cells were examined for sensitivity to Clostridium perfringens biotype D epsilon-toxin. MDCK and G-402 cells were confirmed as ...
Mashiba Harukazu - - 2003
Attempts to cause temporary pore formation of cancer cell membrane and to introduce intracellulary attenuated diphtheria toxin (fDT) following treatment with formaldehyde were performed utilizing high-voltage electric pulses. Human pancreatic cancer cell line (ASPC-1) and lung cancer cell line (PC9) were electroporated in the presence or the absence of fDT. ...
Hayes Finbarr - - 2003
Antibiotic resistance, virulence, and other plasmids in bacteria use toxin-antitoxin gene pairs to ensure their persistence during host replication. The toxin-antitoxin system eliminates plasmid-free cells that emerge as a result of segregation or replication defects and contributes to intra- and interspecies plasmid dissemination. Chromosomal homologs of toxin-antitoxin genes are widely ...
Ghanekar Yashoda - - 2003
The heat-stable enterotoxin peptides (ST) produced by enterotoxigenic Escherichia coli are one of the major causes of transitory diarrhea in the developing world. Toxin binding to its receptor, guanylyl cyclase C (GC-C), results in receptor activation and the production of high intracellular levels of cGMP. GC-C is expressed in two ...
Sui Bao Quan - - 2003
The plasmid-encoded toxin (Pet) from enteroaggregative Escherichia coli is a serine protease autotransporter that acts as an enterotoxin and cytotoxin. When applied to epithelial cells in culture, purified toxin induces cell elongation and rounding, followed by exfoliation of cells from the substratum. These effects are accompanied by loss of actin ...
Dietze A - - 2003
Further advantages in the treatment of soft-tissue sarcomas will only be achieved by tailoring the adjuvant therapy after surgery. The photochemically directed release of macro-molecules from endosomes and lysosomes into the cytosol is a novel technology, named photochemical internalization (PCI), that has been evaluated for treatment of sarcoma cells in ...
Bernardo Paul H - - 2003
The fungal metabolite gliotoxin is characterized by an internal disulfide bridge and can exist in either disulfide or dithiol forms. Gliotoxin and other members of the epipolythiodioxopiperazine class of toxins have immunosuppressive properties and have been implicated in human and animal mycotoxicoses. The bridged disulfide moiety is thought to be ...
Pfeifer Gunther - - 2003
Clostridium difficile toxin B (269 kDa) is one of the causative agents of antibiotic-associated diarrhea and pseudomembranous colitis. Toxin B acts in the cytosol of eukaryotic target cells where it inactivates Rho GTPases by monoglucosylation. The catalytic domain of toxin B is located at the N terminus (amino acid residues ...
Loak Kylie - - 2003
Mammalian asparaginyl endopeptidase (AEP) or legumain is a recently identified lysosomal cysteine protease belonging to clan CD. To date it has been shown to be involved in antigen presentation within class II MHC positive cells and in pro-protein processing. Further elucidation of the biological functions of the enzyme will require ...
Blöcker Dagmar - - 2003
The binary Clostridium botulinum C2 toxin consists of two individual proteins, the transport component C2II (80 kDa) and the enzyme component C2I, which ADP-ribosylates G-actin in the cytosol of cells. Trypsin-activated C2II (C2IIa) forms heptamers that bind to the cell receptor and mediate translocation of C2I from acidic endosomes into ...
Nagahama Masahiro - - 2003
Clostridium perfringens beta toxin is an important agent of necrotic enteritis. Of the 10 cell lines tested, only the HL 60 cell line was susceptible to beta toxin. The toxin induced swelling and lysis of the cell. Treatment of the cells with the toxin resulted in K+ efflux from the ...
Zhao Jin - - 2003
BACKGROUND & OBJECTIVE: Clostridium difficile is recognized as a frequent cause of antibiotic-induced diarrhea. This study was designed to investigate whether Clostridium difficile toxin A might induce apoptosis on human hepatoma cell line SMMC7721 and African green monkey kidney Vero cells. METHODS: Highly purified toxin A was obtained by bovine ...
Shimizu Takeshi - - 2003
It is well recognized that the Shiga-like toxins (Stxs) preferentially bind to Gb3 glycolipids and the cholera toxin (CT) and heat-labile enterotoxin (LTp) bind to GM1 gangliosides. After binding to the cell surface, A-B bacterial enterotoxins have to be internalized by endocytosis. The transport of the toxin-glycolipid complex has been ...
Bebb James R - - 2003
We show here that Helicobacter pylori broth culture supernatants disrupt the actin cytoskeleton of epithelial cell lines, leading to cell rounding and apoptosis through anoikis. We demonstrate that there are marked quantitative differences between strains and that there are different cell line sensitivities. By constructing VacA null isogenic mutants, we ...
Maggiora Marina - - 2003
The action of 4-hydroxynonenal (HNE), a chemotactic aldehyde produced by lipid peroxidation, was analysed on exocytosis in parallel with its effects on phosphoinositide-specific phospholipase C (PLC) both in undifferentiated HL-60 cells and in cells induced to differentiate toward the granulocytic cell line by 1.25% DMSO. Exocytosis was evaluated by the ...
Barusrux Sahawat - - 2003
The pathological effect of the Bacillus thuringiensis Cry delta- endotoxins on susceptible insect larvae had extensive damage on the midgut epithelial cells. In this study, an ex vivo assay was devised for assessing the insecticidal potency of the cloned Cry4B mosquito-larvicidal protein that is expressed in Escherichia coli. Determination of ...
Singh Raman Deep - - 2003
We studied the endocytosis of fluorescent glycosphingolipid (GSL) analogs in various cell types using pathway-specific inhibitors and colocalization studies with endocytic markers and DsRed caveolin-1 (cav-1). Based on inhibitor studies, all GSLs tested were internalized predominantly (>80%) by a clathrin-independent, caveolar-related mechanism, regardless of cell type. In addition, fluorescent lactosylceramide ...
Manger Ronald L - - 2003
Although cytotoxicity assays provide several advantages over mouse bioassays, sodium channel-blocking marine toxins, such as those associated with paralytic shellfish poison (PSP), require prolonged incubation periods of 24-48 h. This is in marked contrast to in vitro detection of sodium channel-enhancing marine toxins such as ciguatoxins or brevetoxins which can ...
Donelli Gianfranco - - 2003
To investigate the mode of action of Clostridium perfringens epsilon-toxin, MDCK cells were treated with purified toxin and incubated at 37 degrees C for up to 24h. Exposure to epsilon-toxin caused a time-dependent decrease in cell-cell and cell-substrate interactions. After 30min of treatment retraction of the cell body and the ...
Banks D J - - 2003
We previously identified a novel Heliothis virescens 110 kDa aminopeptidase N (APN) that binds Bacillus thuringiensis (Bt) Cry1Ac and Cry1Fa delta-endotoxins, and cloned an internal region of the 110 kDa APN gene (Banks et al., 2001). Here we describe the RACE-PCR cloning and sequence of a cDNA encoding 110 kDa ...
Weaver Keith E - - 2003
Fst is a peptide toxin encoded by the par toxin-antitoxin stability determinant of Enterococcus faecalis plasmid pAD1. Intracellular overproduction of Fst resulted in simultaneous inhibition of all cellular macromolecular synthesis concomitant with cell growth inhibition and compromised the integrity of the cell membrane. Cells did not lyse or noticeably leak ...
Minisini Rosalba - - 2003
An open reading frame (ORF), US28, with homology to mammalian chemokine receptors has been identified in the genome of human cytomegalovirus (HCMV). Its protein product, pUS28, has been shown to bind several human CC chemokines, including RANTES, MCP-1, and MIP-1 alpha, and the CX(3)C chemokine fractalkine with high affinity. Addition ...
Matsushima-Hibiya Yuko - - 2003
Pierisin-1, a cytotoxic protein found naturally in the cabbage butterfly, induces apoptosis of mammalian cells. Our recent studies suggest that pierisin-1 consists of an N-terminal ADP-ribosyltransferase domain, and a C-terminal region that binds to receptors on the surfaces of target cells and incorporates the protein into cells. The present study ...
Chen Ming - - 2003
BACKGROUND: Pyelonephritis is a risk factor for renal tubular epithelial cell damage. Recent studies have shown that Escherichia coli and/or its toxins may stimulate apoptotic cell death in renal tubular cells, but the underlying molecular mechanisms remain to be elucidated. METHODS: Confluent LLC-PK(1) cells were exposed to E. coli toxins ...
Dziak R - - 2003
The effects of the lysophospholipids, sphingosine-1-phosphate (S1P) and lysophosphatidic acid (LPA) were studied in human primary osteoblastic cells and the human osteosarcomal cell lines, G292 and MG-63. The studies focused on the role of the Gi protein in the regulation of S1P and LPA-induced proliferation, the effects of the phospholipids ...
Klegeris Andis - - 2003
To explore whether the proinflammatory products of the 5-lipoxygenase (5-LOX) pathway are involved in microglia-mediated toxicity toward neuronal cells, we evaluated the effects of 5-LOX inhibitors using an in vitro assay system where human neuronal SH-SY5Y cells are exposed to toxic secretions from THP-1 monocytic cells or human microglia. The ...
Han Thomas K - - 2003
Massive deaths of manatees (Trichechus manatus latirostris) during the red tide seasons have been attributed to brevetoxins produced by the dinoflagellate Karenia brevis (formerly Ptychodiscus breve and Gymnodinium breve). Although these toxins have been found in macrophages and lymphocytes in the lung, liver, and secondary lymphoid tissues of these animals, ...
Snyder D Scott - - 2003
Mycolactone is a macrolide secreted by Mycobacterium ulcerans. Experimental evidence suggests that mycolactone plays a prominent role in the pathogenesis of Buruli ulcer by causing both tissue destruction and immunosuppression. To understand the cell biology of mycolactone activity, we have synthesized the fluorescent mycolactone derivativebodipymycolactone. Although derivatization resulted in a ...
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