Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038362 (stomatitis)
 8,852 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The inactivation of enveloped viruses by two different solvent/detergent combinations, i.e. tri-n-butyl phosphate (TNBP)/Triton X-100 or TNBP/Tween 80, has been investigated using a high purity factor VIII (Replenate) and factor IX (Replenine) respectively. Treatment with TNBP/Triton X-100 rapidly inactivated all the typical enveloped viruses tested, i.e. Sindbis, semliki forest virus (SFV), herpes simplex virus type-1 (HSV-1) and vesicular stomatitis virus (VSV), by 3.7-5.8 log within 15 seconds. While virus inactivation with TNBP/Tween 80 was slower, effective inactivation of Sindbis, HSV-1, VSV and human immunodeficiency virus type-1, i.e. 4.1-->6.3 log, occurred within 30 minutes. In contrast, vaccinia virus was relatively resistant to inactivation in either of these solvent/detergent combinations. Incubation times of 10 minutes for TNBP/Triton X-100 or 6-24 hours for TNBP/Tween 80, were required to reach inactivation levels of about 4 log.
 ...
PMID:Resistance of vaccinia virus to inactivation by solvent/detergent treatment of blood products. 1079 53

Phosphatidylinositols (PI) play important roles in regulating numerous cellular processes including cytoskeletal organization and membrane trafficking. The control of PI metabolism by phosphatidylinositol kinases has been the subject of extensive investigation; however, little is known about how phosphatidylinositol kinases regulate traffic in polarized epithelial cells. Because phosphatidylinositol 4-kinase (PI4K)-mediated phosphatidylinositol 4-phosphate (PI(4)P) production has been suggested to regulate biosynthetic traffic in yeast and mammalian cells, we have examined the role of PI4Kbeta in protein delivery in polarized MDCK cells, at different levels of the biosynthetic pathway. Expression of wild type PI4Kbeta had no effect on the rate of transport of influenza hemagglutinin (HA) through the Golgi complex, but inhibited the rate of trans-Golgi network (TGN)-to-cell surface delivery of this protein. By contrast, expression of dominant-negative, kinase-dead PI4Kbeta (PI4Kbeta(D656A)) inhibited intra-Golgi transport but stimulated TGN-to-cell surface delivery of HA. Moreover, expression of PI4Kbeta(D656A) significantly increased the solubility in cold Triton X-100 of HA staged in the TGN, suggesting that altered association of HA with lipid rafts may be responsible for the enhanced transport rate. Both wild type and kinase-dead PI4Kbeta inhibited basolateral delivery of vesicular stomatitis virus G protein, suggesting an effector function for PI4Kbeta in the regulation of basolateral traffic. Thus, by contrast with the observed requirement for PI4Kbeta activity and PI(4)P for efficient transport in yeast, our data suggest that changes in PI(4)P levels can stimulate and inhibit Golgi to cell surface delivery in mammalian cells.
 ...
PMID:Multiple roles for phosphatidylinositol 4-kinase in biosynthetic transport in polarized Madin-Darby canine kidney cells. 1170 66

Combretastatin A-4 phosphate (CA4P) is a novel antitumor vascular targeting agent, the first agent of this class of compounds to enter the clinic. We performed a Phase I trial to determine the maximum-tolerated dose, safety, and pharmacokinetic profile of CA4P on a single-dose i.v. schedule. We also obtained preliminary data on its effect on tumor blood flow using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) techniques and cell adhesion molecules at the higher-dose levels. Twenty-five assessable patients with advanced cancer received a total of 107 cycles over the following dose escalation schema: 18, 36, 60, 90 mg/m(2) as a 10-min infusion and 60 mg/m(2) as a 60-min infusion at 3-week intervals. There was no significant myelotoxicity, stomatitis, or alopecia. Tumor pain was a unique side effect, which occurred in 10% of cycles, and there were four episodes of dose-limiting toxicity at dosages > or =60 mg/m(2), including two episodes of acute coronary syndrome. Pharmacokinetics revealed rapid dephosphorylation of the parent compound (CA4P) to combretastatin A4 (CA4), with a short plasma half-life (approximately 30 min). A significant (P < 0.03) decline in gradient peak tumor blood flow by DCE-MRI in six of seven patients treated at 60 mg/m(2) was observed. A patient with anaplastic thyroid cancer had a complete response and is alive 30 months after treatment. The toxicity profile is consistent with a drug that is "vascularly active" and devoid of traditional "cytotoxic" side effects. Dosages < or =60 mg/m(2) as a 10-min infusion define the upper boundary of the maximum-tolerated dose.
 ...
PMID:A phase I pharmacokinetic and translational study of the novel vascular targeting agent combretastatin a-4 phosphate on a single-dose intravenous schedule in patients with advanced cancer. 1206 83

The phosphoprotein (P) of vesicular stomatitis virus (VSV) is an essential subunit of the viral RNA-dependent RNA polymerase (RdRp) complex. It is phosphorylated at two different domains. Using defective interfering (DI) RNA or minigenomic RNA templates, we previously demonstrated that phosphorylation within the amino-terminal domain I is essential for transcription, whereas phosphorylation within the carboxy-terminal domain II is necessary for replication. For the present study, we examined the role of the phosphorylation of residues in these domains in the life cycle of VSV. Various mutant P coding sequences were inserted into a full-length cDNA clone of VSV, and the virus recovery, kinetics of growth, and mRNA and protein synthesis were examined. We observed that virus recovery was completely abolished when all three phosphate acceptor sites in domain I or both sites in domain II were replaced with alanine. Single or double mutations in domain I (with the exception of P60/64) or single mutations in domain II had no adverse effect on virus recovery. VSVP227, carrying alanine at position 227, showed reduced kinetics of virus growth but increased kinetics of viral mRNA synthesis in infected cells. More interestingly, this particular virus exhibited a significantly reduced cytopathic effects and apoptosis in infected cells, implying that P may be involved in these processes. Furthermore, we found that DI RNAs of different sizes were generated by high-multiplicity passaging of various mutant VSVs, indicating that the viral RdRp may play a significant role in the process of DI particle generation. Taken together, our results suggest that the phosphorylation of residues in domains I and II of VSV P is indispensable for virus growth.
 ...
PMID:Phosphorylation of vesicular stomatitis virus phosphoprotein P is indispensable for virus growth. 1516 35

During viral infection, fusion of the viral envelope with endosomal membranes and nucleocapsid release were thought to be concomitant events. We show here that for the vesicular stomatitis virus they occur sequentially, at two successive steps of the endocytic pathway. Fusion already occurs in transport intermediates between early and late endosomes, presumably releasing the nucleocapsid within the lumen of intra-endosomal vesicles, where it remains hidden. Transport to late endosomes is then required for the nucleocapsid to be delivered to the cytoplasm. This last step, which initiates infection, depends on the late endosomal lipid lysobisphosphatidic acid (LBPA) and its putative effector Alix/AIP1, and is regulated by phosphatidylinositol-3-phosphate (PtdIns3P) signalling via the PtdIns3P-binding protein Snx16. We conclude that the nucleocapsid is exported into the cytoplasm after the back-fusion of internal vesicles with the limiting membrane of late endosomes, and that this process is controlled by the phospholipids LBPA and PtdIns3P and their effectors.
 ...
PMID:Endosome-to-cytosol transport of viral nucleocapsids. 1599 Aug 91

The osteocyte is the most abundant cell type in bone and is embedded in mineralized bone matrix. Osteocytes are still poorly characterized because of their location and the lack of primary osteocyte isolation methods. Data on the cell biology of osteocytes is especially limited. We have isolated primary osteocytes from rat cortical bone by applying repeated enzymatic digestion and decalcification. The isolated osteocytes expressed typical osteocytic morphology with cell-cell contacts via long protrusions after a 1-day culture. These cells were negative or faintly positive for alkaline phosphatase but expressed high levels of osteocalcin, PHEX (phosphate-regulating gene with homology to endopeptidases on the X chromosome), and DMP1 (dentin matrix protein 1). These cells also revealed patchy membrane staining for connexin43. For studying the function of gap junctions in isolated osteocytes, we microinjected rhodamine-labeled dextran (MW: 10,000) and Lucifer yellow (MW: 457) and found that Lucifer yellow was rapidly transmitted to several surrounding cells, whereas dextran remained in the injected cells. Heptanol and 18alpha-glycyrrhetinic acid inhibited the transfer of Lucifer yellow. This clearly showed the existence of functional gap junctions in cultured osteocytes. Enveloped viruses, such as vesicular stomatitis virus and influenza A virus, were used for studying cell polarity. We were unable to demonstrate plasma membrane polarization with enveloped viruses in isolated primary osteocytes in culture. Our results suggest that osteocytes do not possess apical and basolateral plasma membrane domains as do osteoblasts, which are their precursors.
 ...
PMID:Isolated primary osteocytes express functional gap junctions in vitro. 1617 87

Low levels of gene delivery in vivo using replication-defective retroviral vectors have severely limited their application for clinical protocols. To overcome this problem, we describe here a semi-replication-competent retrovirus (s-RCR) in which the gag-pol and envelope (VSV-G, vesicular stomatitis virus G protein) genes were split into two vectors. This system offers potential advantages over both replication-defective vectors, in terms of efficiency of in vivo spread through a tumor, and all-in-one replication-competent vectors in terms of the payload of therapeutic genes that can be carried. We achieved a viral titer of s-RCR viruses approximately 70-fold higher than VSV-G pseudotyped, replication-defective vectors. In addition, s-RCR vectors induced tumor killing by the cytotoxicity of VSV-G during viral spread. Inclusion of the herpes simplex virus thymidine kinase (HSVtk30) gene into vectors significantly improved tumor killing activity followed by ganciclovir (GCV) treatment in vitro under conditions of low-level viral replication. However, at high levels of viral spread, VSV-G-mediated cytotoxicity predominated. Xenografts of human fibrosarcoma HT1080 cells, preinfected by semi-replicative green fluorescent protein vectors (semi-GFP), were completely non-tumorigenic in nude mice. Implantation of cells preinfected by semi-replicative TK30 vectors (semi-TK30) mixed with parental HT1080 cells at a ratio of 1:1 efficiently prevented tumor growth in mice treated by GCV. Direct intratumoral injection of HT1080 tumors growing in nude mice, or B16 murine melanoma in immunocompetent mice, with semi-TK30 viruses significantly prolonged survival. Injection of autologous cells (B16) producing semi-TK30 vector into B16 tumors prolonged survival only in mice treated with GCV but not with phosphate-buffered saline (PBS). In contrast, when xenogeneic cells (293T) producing semi-TK30 vectors were injected into B16 tumors, an optimal survival advantage was obtained in mice treated with PBS rather than GCV. These data indicate that complex interactions exist between direct cytotoxicity of VSV-G and HSVtk expression when placed in the context of additional immune parameters, which combine to determine the efficacy of the therapy. Taken together, our data suggest that s-RCR vectors have some potential advantages for development to deliver genes into tumors for cancer treatment but that a combination of factors will impact on the decision as to whether the s-RCR strategy is worth developing to full clinical trials.
 ...
PMID:VSV-G pseudotyped, MuLV-based, semi-replication-competent retrovirus for cancer treatment. 1672 95

Previous studies demonstrated that sphingosine-1-phosphate (S1P) phosphohydrolase 1 (SPP-1), which is located mainly in the endoplasmic reticulum (ER), regulates sphingolipid metabolism and apoptosis (H. Le Stunff et al., J. Cell Biol. 158:1039-1049, 2002). We show here that the treatment of SPP-1-overexpressing cells with S1P, but not with dihydro-S1P, increased all ceramide species, particularly the long-chain ceramides. This was not due to inhibition of ceramide metabolism to sphingomyelin or monohexosylceramides but rather to the inhibition of ER-to-Golgi trafficking, determined with the fluorescent ceramide analog N-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-pentanoyl)-d-erythro-sphingosine (DMB-Cer). Fumonisin B1, an inhibitor of ceramide synthase, prevented S1P-induced elevation of all ceramide species and corrected the defect in ER transport of DMB-Cer, readily allowing its detection in the Golgi. In contrast, ceramide accumulation had no effect on either the trafficking or the metabolism of 6-([N-(7-nitrobenzo-2-oxa-1,3-diazol-4-yl)amino]hexanoyl)-sphingosine, which rapidly labels the Golgi even at 4 degrees C. Protein trafficking from the ER to the Golgi, determined with vesicular stomatitis virus ts045 G protein fused to green fluorescent protein, was also inhibited in SPP-1-overexpressing cells in the presence of S1P but not in the presence of dihydro-S1P. Our results suggest that SPP-1 regulates ceramide levels in the ER and thus influences the anterograde membrane transport of both ceramide and proteins from the ER to the Golgi apparatus.
 ...
PMID:Sphingosine-1-phosphate phosphohydrolase regulates endoplasmic reticulum-to-golgi trafficking of ceramide. 1678 91

Rhabdovirus is a negative strand RNA virus that packages a ribonucleoprotein (RNP) complex. The RNP is composed of a genome that is encapsidated completely by the nucleoprotein (N). Structural comparisons of the RNA-nucleoprotein complexes from two members, vesicular stomatitis virus (VSV) and rabies virus (RABV), revealed highly conserved characteristics of folding, RNA binding, and assembly despite their lack of significant homology in amino acid sequence. The RNA binding cavity is located between two conserved domains formed by alpha-helices, but the positively charged residues that coordinate with the phosphate groups are at different sites. The intermolecular interactions among N molecules have a conserved pattern that is rendered, however, by different residues. The curvature of the RABV N-RNA complex in the crystal structure is larger than that of the VSV N-RNA complex. The more relaxed curvature allows the bases in the RNA to stack more tightly, and at the same time, the helices near the C-terminus move into the created space in order to cover the bound RNA. This may explain how the RNP can adopt different conformations from being packed as a superhelix in the virion to a relaxed linear structure once being delivered into the cytoplasm.
 ...
PMID:Conserved characteristics of the rhabdovirus nucleoprotein. 1776 75

Phosphatidylinositol-3-phosphate kinase (PI3K) has been reported to exhibit anti-inflammatory roles as a negative modulator of the NF-kappaB pathway (MyD88- and Mal-dependent) triggered upon Toll-like receptor (TLR)4 activation by lipopolysaccharide (LPS). Here, we investigated the role of PI3K on the TLR4-dependent, MyD88-independent signaling cascade which is activated in macrophages infected by Vesicular Stomatitis Virus (VSV) and leads to interferon production, thus conferring antiviral protection. We show that VSV induces TLR4 (and CD14)-dependent Akt phosphorylation. We observed hypersusceptibility to viral infections after pharmacological inactivation of the PI3K pathway in macrophages, which indicates that normal PI3K functions are critical for type I interferon synthesis and viral resistance. Conversely, we noticed increased resistance in macrophages isolated from genetically modified mice in which the PI3K pathway is constitutively active. Our data, which demonstrate that PI3K-Akt axis is an important component of the TLR4-dependent antiviral mechanism, also indicate that pharmacological modulation of this pathway to regulate the inflammatory response could promote viral susceptibility.
 ...
PMID:TLR4/CD14-mediated PI3K activation is an essential component of interferon-dependent VSV resistance in macrophages. 1833 26


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>