996 resultados para C-11 HYDROCARBONS
Resumo:
Bone morphogenetic protein (BMP)-2 and transforming growth factor (TGF)-beta1 are multifunctional cytokines both proposed as stimulants for cartilage repair. Thus it is crucial to closely examine and compare their effects on the expression of key markers of the chondrocyte phenotype, at the gene and protein level. In this study, the expression of alpha 10 and alpha 11 integrin subunits and the IIA/IIB spliced forms of type II procollagen have been monitored for the first time in parallel in the same in vitro model of mouse chondrocyte dedifferentiation/redifferentiation. We demonstrated that TGF-beta1 stimulates the expression of the non-chondrogenic form of type II procollagen, IIA isoform, and of a marker of mesenchymal tissues, i.e. the alpha 11 integrin subunit. On the contrary, BMP-2 stimulates the cartilage-specific form of type II procollagen, IIB isoform, and a specific marker of chondrocytes, i.e. the alpha 10 integrin subunit. Collectively, our results demonstrate that BMP-2 has a better capability than TGF-beta1 to stimulate chondrocyte redifferentiation and reveal that the relative expressions of type IIB to type IIA procollagens and alpha 10 to alpha 11 integrin subunits are good markers to define the differentiation state of chondrocytes. In addition, adenoviral expression of Smad6, an inhibitor of BMP canonical Smad signaling, did not affect expression of total type II procollagen or the ratio of type IIA and type IIB isoforms in mouse chondrocytes exposed to BMP-2. This result strongly suggests that signaling pathways other than Smad proteins are involved in the effect of BMP-2 on type II procollagen expression.
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Purpose: To work out certain, well‑defined aetiologies frequently associated with mesenteric venous thrombosis (MVT) in order to predict a typical population at risk, since MVT is nowadays often incidentally detected on cross‑sectional imaging. To demonstrate the MDCT features, frequency and extent of associated bowel ischemia according to the underlying pathology. Methods and Materials: Our electronic database revealed 71 patients (25 women, mean age 55) with thrombosis of the superior and/or inferior mesenteric vein detected by MDCT between 2000 and 2008. Two radiologists jointly reviewed the corresponding MDCT features including intraluminal extension, underlying aetiology and associated bowel ischemia, if present. Results: MVT was associated with carcinoma in 31 (43.7%) patients (pancreas 21.1%, liver 9.9%, others 12.7%). Concomitant inflammation was seen in 15 (21.1%) patients (pancreatitis 11.3%, diverticulitis 4.2%, others 5.6%), whereas coagulation/hematologic disorders were found in 7 (9.9%) patients, liver cirrhosis in 6 (8.5%), mixed/miscellaneous causes in 5 (7%) and still unknown aetiologies in 5 patients (7%). MVT resulted from recent operations in 2 (2.8%) patients. MDCT features of venous bowel ischemia were present in 15 patients (21.1%). 46.5% of MVT were (sub)acute, while 53.5% chronic. The luminal extension was complete in 52.1%, subtotal (50% of lumen) in 22.5% and partial (50% of lumen) in 25.4% of patients, consisting either of blood clots (76.1%) or tumoral tissue (23.9%), the latter mainly due to pancreas adenocarcinoma (76.4%). Conclusion: MDCT features of MVT are seen with a wide range of underlying diseases. Signs of intestinal ischemia are infrequently associated, mostly occurring with coagulation/hematologic disorders (40%).
Resumo:
PURPOSE: To assess the feasibility and activity of radio-chemotherapy with mitomycin C (MMC) and cisplatin (CDDP) in locally advanced squamous cell anal carcinoma with reference to radiotherapy (RT) combined with MMC and fluorouracil (5-FU). PATIENTS AND METHODS: Patients with measurable disease >4 cmN0 or N+ received RT (36Gy+2 week gap+23.4Gy) with either MMC/CDDP or MMC/5-FU (MMC 10mg/m(2) d1 of each sequence; 5-FU 200mg/m(2)/day c.i.v. daily; CDDP 25mg/m(2) weekly). Forty patients/arm were needed to exclude a RECIST objective response rate (ORR), 8 weeks after treatment, of <75% (Fleming 1, alpha=10%, beta=10%). RESULTS: The ORR was 79.5% (31/39) (lower bound confidence interval [CI]: 68.8%) with MMC/5-FU versus 91.9% (34/ 37) (lower bound CI: 82.8%) with MMC/CDDP. In the MMC/5-FU group, two patients (5.1%) discontinued treatment due to toxicity versus 11 (29.7%) in the MMC/CDDP group. Nine grade 3 haematological events occurred with MMC/CDDP versus none with 5-FU/MMC. The rate of other toxicities did not differ. There was no toxic death. Thirty-one patients in the MMC/5-FU arm (79.5%) and 18 in the MMC/CDDP arm (48.6%) were fully compliant with the protocol treatment (p=0.005). CONCLUSIONS: Radio-chemotherapy with MMC/CDDP seems promising as only MMC/CDDP demonstrated enough activity (RECIST ORR >75%) to be tested further in phase III trials; MMC/5-FU did not. MMC/CDDP also had an overall acceptable toxicity profile.
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We used high-resolution swath-bathymetry data to characterise the morphology of the abandoned subaqueous Sol de Riu delta lobe in the Ebro Delta, Western Mediterranean Sea. This study aims to assess the influence of an abandoned delta lobe on present-day coastal dynamics in a micro-tidal environment. Detailed mapping of the relict Sol de Riu lobe also showed a set of bedforms interpreted as footprints of human activities: seasonal V-shaped depressions on the middle shoreface due to boat anchoring and old trawling marks between 16 and 18 m water depth. Estimations of the mobility of bottom sediment showed that the shallowest shoreface (i.e. less than 7 m depth) is the most dynamic part of the relict lobe, while the middle shoreface experienced significant morphological changes since the lobe was abandoned. The deepest shoreface (i.e. water depth in excess of 15 m), which corresponds to the front of the lobe, is defined by a very small potential for morphological change. Simulations showed that while the relict lobe does not significantly affect the typical short period waves (Tp ≈4 s) in the study area, it does interfere with the most energetic wave conditions (Tp ≥ 7 s) acting as a shoal leading to the concentration of wave energy along the shoreline northwest of the lobe. The consequence of such modification of the high-energy wave propagation pattern by the relict lobe is an alteration of the wave-induced littoral sediment dynamics with respect to a situation without the lobe.
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Induction of the C/EBP homologous protein (CHOP) is considered a key event for endoplasmic reticulum (ER) stress-mediated apoptosis. Type 1 diabetes (T1D) is characterized by an autoimmune destruction of the pancreatic β-cells. Pro-inflammatory cytokines are early mediators of β-cell death in T1D. Cytokines induce ER stress and CHOP overexpression in β-cells, but the role for CHOP overexpression in cytokine-induced β-cell apoptosis remains controversial. We presently observed that CHOP knockdown (KD) prevents cytokine-mediated degradation of the anti-apoptotic proteins B-cell lymphoma 2 (Bcl-2) and myeloid cell leukemia sequence 1 (Mcl-1), thereby decreasing the cleavage of executioner caspases 9 and 3, and apoptosis. Nuclear factor-κB (NF-κB) is a crucial transcription factor regulating β-cell apoptosis and inflammation. CHOP KD resulted in reduced cytokine-induced NF-κB activity and expression of key NF-κB target genes involved in apoptosis and inflammation, including iNOS, FAS, IRF-7, IL-15, CCL5 and CXCL10. This was due to decreased IκB degradation and p65 translocation to the nucleus. The present data suggest that CHOP has a dual role in promoting β-cell death: (1) CHOP directly contributes to cytokine-induced β-cell apoptosis by promoting cytokine-induced mitochondrial pathways of apoptosis; and (2) by supporting the NF-κB activation and subsequent cytokine/chemokine expression, CHOP may contribute to apoptosis and the chemo attraction of mononuclear cells to the islets during insulitis.
Resumo:
The hepatitis C virus (HCV) NS3-4A protease is not only an essential component of the viral replication complex and a prime target for antiviral intervention but also a key player in the persistence and pathogenesis of HCV. It cleaves and thereby inactivates two crucial adaptor proteins in viral RNA sensing and innate immunity, mitochondrial antiviral signaling protein (MAVS) and TRIF, a phosphatase involved in growth factor signaling, T-cell protein tyrosine phosphatase (TC-PTP), and the E3 ubiquitin ligase component UV-damaged DNA-binding protein 1 (DDB1). Here we explored quantitative proteomics to identify novel cellular substrates of the NS3-4A protease. Cell lines inducibly expressing the NS3-4A protease were analyzed by stable isotopic labeling using amino acids in cell culture (SILAC) coupled with protein separation and mass spectrometry. This approach identified the membrane-associated peroxidase GPx8 as a bona fide cellular substrate of the HCV NS3-4A protease. Cleavage by NS3-4A occurs at Cys 11, removing the cytosolic tip of GPx8, and was observed in different experimental systems as well as in liver biopsies from patients with chronic HCV. Overexpression and RNA silencing studies revealed that GPx8 is involved in viral particle production but not in HCV entry or RNA replication. Conclusion: We provide proof-of-concept for the use of quantitative proteomics to identify cellular substrates of a viral protease and describe GPx8 as a novel proviral host factor targeted by the HCV NS3-4A protease. (Hepatology 2014;59:423-433).
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The use of High Performance Concrete (HPC) in Iowa has consisted of achieving slightly higher compressive strengths with an emphasis on reduced permeability. Concrete with reduced permeability has increased durability by slowing moisture and chloride ingress. Achieving reduced permeability has typically been accomplished with combinations of slag and Class C fly ash, or the use of blended cements such as locally available Type IS(20), IS(25) and Type IP(25) in conjunction with Class C fly ash. Fly ash has been used in the majority of concrete placed in Iowa since 1984 and slag has been available in Iowa since 1995. During the economic downturn in 2008, one of the cement plants that produced a Type IS(25) cement was forced to shut down, which reduced the availability of blended cements, typically used on HPC deck overlays. Recently, a source of high reactivity metakaolin has been made available. Metakaolin is produced by heating a pure kaolinite clay to 650 to 700 °C in a rotary kiln (calcining). Metakaolin is a white pozzolan that is used to produce concrete with increased strengths, reduced permeability, reduced efflorescence, and resistance to alkali silica reactivity. The W.R. Grace MK-100 metakaolin will likely be available in dissolvable bags between 25 and 50 pounds. Thus, the mix designs were based on the anticipated bag size range for field use. This research evaluated metakaolin mixes with and without Class C fly ash. Results indicated a seven percent replacement with metakaolin produced concrete with increased strengths and low permeability. When used with Class C fly ash, permeability is reduced to very low rating. Metakaolin may be used to enhance hardened concrete properties for use in high performance concrete (HPC).
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Fast track concrete has proven to be successful in obtaining high early strengths. This benefit does not come without cost. Type III cement and insulation blankets to accelerate the cure add to its expense when compared to conventional paving. This research was intended to determine the increase in time required to obtain opening strength when a fast track mix utilized conventional Type I cement and also used a conventional cure. Standard concrete mixes also were tested to determine the acceleration of strength gain when cured with insulation blankets. The goal was to determine mixes and procedures which would result in a range of opening times. This would allow the most economical design for a particular project and tailor it to that projects time restraint. Three mixes were tested: Class F, Class C, and Class B. Each mix was tested with one section being cured with insulation blankets and another section without. All used Type I cement. Iowa Department of Transportation specifications required 500 psi of flexural strength before a pavement can be opened to traffic. The Class F mix with Type I cement and using insulation blankets reached that strength in approximately 36 hours, the Class C mix using the blankets in approximately 48 hours, and the Class F mix without covers in about 60 hours. (Note: Class F concrete pavement is opened at 400 psi minimum and Class F bonded overlay pavement at 350 psi.) The results showed a significant improvement in early strength gain by the use of insulation blankets. The Type I cement could be used in mixes intended for early opening with sacrifices in time when compared to fast track but are still much sooner than conventional pavement. It appears a range of design alternatives is possible using Type I cement both with and without insulating blankets.
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We evaluated the role of the G alpha-q (Galphaq) subunit of heterotrimeric G proteins in the insulin signaling pathway leading to GLUT4 translocation. We inhibited endogenous Galphaq function by single cell microinjection of anti-Galphaq/11 antibody or RGS2 protein (a GAP protein for Galphaq), followed by immunostaining to assess GLUT4 translocation in 3T3-L1 adipocytes. Galphaq/11 antibody and RGS2 inhibited insulin-induced GLUT4 translocation by 60 or 75%, respectively, indicating that activated Galphaq is important for insulin-induced glucose transport. We then assessed the effect of overexpressing wild-type Galphaq (WT-Galphaq) or a constitutively active Galphaq mutant (Q209L-Galphaq) by using an adenovirus expression vector. In the basal state, Q209L-Galphaq expression stimulated 2-deoxy-D-glucose uptake and GLUT4 translocation to 70% of the maximal insulin effect. This effect of Q209L-Galphaq was inhibited by wortmannin, suggesting that it is phosphatidylinositol 3-kinase (PI3-kinase) dependent. We further show that Q209L-Galphaq stimulates PI3-kinase activity in p110alpha and p110gamma immunoprecipitates by 3- and 8-fold, respectively, whereas insulin stimulates this activity mostly in p110alpha by 10-fold. Nevertheless, only microinjection of anti-p110alpha (and not p110gamma) antibody inhibited both insulin- and Q209L-Galphaq-induced GLUT4 translocation, suggesting that the metabolic effects induced by Q209L-Galphaq are dependent on the p110alpha subunit of PI3-kinase. In summary, (i) Galphaq appears to play a necessary role in insulin-stimulated glucose transport, (ii) Galphaq action in the insulin signaling pathway is upstream of and dependent upon PI3-kinase, and (iii) Galphaq can transmit signals from the insulin receptor to the p110alpha subunit of PI3-kinase, which leads to GLUT4 translocation.
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Objective: To describe the clinical, radiological and histopathological features of lateral periodontal cysts among patients diagnosed in different centers (Vall d"Hebron General Hospital, Granollers General Hospital, the Teknon Medical Center, and the Master of Oral Surgery and Implantology of the University of Barcelona Dental School; Barcelona, Spain). Study design: A retrospective observational study was made of 11 lateral periodontal cysts, all of which were diagnosed following a thorough clinical examination, radiological study and posterior histological study. Results: The mean patient age was 37 years, and males predominated over females. The mean lesion size was 1.25 cm. A single relapse was recorded 7 years after removal of the initial lesion. All the cysts were surgically removed. Discussion and conclusions: Lateral periodontal cysts are very infrequent, and are characterized by the preserved vitality of the adjacent teeth. Identification of the lesion is initially based on the clinical findings, though histological study is required to confirm the diagnosis. The treatment of choice is the surgical removal, though occasional relapses have been documented
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Nonstructural protein 4B (NS4B) is a key organizer of hepatitis C virus (HCV) replication complex formation. In concert with other nonstructural proteins, it induces a specific membrane rearrangement, designated as membranous web, which serves as a scaffold for the HCV replicase. The N-terminal part of NS4B comprises a predicted and a structurally resolved amphipathic α-helix, designated as AH1 and AH2, respectively. Here, we report a detailed structure-function analysis of NS4B AH1. Circular dichroism and nuclear magnetic resonance structural analyses revealed that AH1 folds into an amphipathic α-helix extending from NS4B amino acid 4 to 32, with positively charged residues flanking the helix. These residues are conserved among hepaciviruses. Mutagenesis and selection of pseudorevertants revealed an important role of these residues in RNA replication by affecting the biogenesis of double-membrane vesicles making up the membranous web. Moreover, alanine substitution of conserved acidic residues on the hydrophilic side of the helix reduced infectivity without significantly affecting RNA replication, indicating that AH1 is also involved in virus production. Selective membrane permeabilization and immunofluorescence microscopy analyses of a functional replicon harboring an epitope tag between NS4B AH1 and AH2 revealed a dual membrane topology of the N-terminal part of NS4B during HCV RNA replication. Luminal translocation was unaffected by the mutations introduced into AH1, but was abrogated by mutations introduced into AH2. In conclusion, our study reports the three-dimensional structure of AH1 from HCV NS4B, and highlights the importance of positively charged amino acid residues flanking this amphipathic α-helix in membranous web formation and RNA replication. In addition, we demonstrate that AH1 possesses a dual role in RNA replication and virus production, potentially governed by different topologies of the N-terminal part of NS4B.