Home About us Contact
|
Home About us Contact | ||
|
|
||
Entry Site (entry + site)
Kinds of Entry Site Selected AbstractsGlobal analysis of functional surfaces of core histones with comprehensive point mutantsGENES TO CELLS, Issue 1 2007Kazuko Matsubara The core histones are essential components of the nucleosome that act as global negative regulators of DNA-mediated reactions including transcription, DNA replication and DNA repair. Modified residues in the N-terminal tails are well characterized in transcription, but not in DNA replication and DNA repair. In addition, roles of residues in the core globular domains are not yet well characterized in any DNA-mediated reactions. To comprehensively understand the functional surface(s) of a core histone, we constructed 320 yeast mutant strains, each of which has a point mutation in a core histone, and identified 42 residues responsible for the suppressor of Ty (Spt - ) phenotypes, and 8, 30 and 61 residues for sensitivities to 6-azauracil (6AU), hydroxyurea (HU) and methyl-methanesulfonate (MMS), respectively. In addition to residues that affect one specific assay, residues involved in multiple reactions were found, and surprisingly, about half of them were clustered at either the nucleosome entry site, the surface required for nucleosome,nucleosome interactions in crystal packing or their surroundings. This comprehensive mutation approach was proved to be powerful for identification of the functional surfaces of a core histone in a variety of DNA-mediated reactions and could be an effective strategy for characterizing other evolutionarily conserved hub-like factors for which surface structural information is available. [source] Place and value of the recurrent laryngeal nerve (RLN) palpatory method in preventing RLN palsy during thyroid surgeryHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 4 2009DSci, Áron Altorjay MD Abstract Background. In recent years, certain publications have appeared confirming that intraoperative palpation of the recurrent laryngeal nerve (RLN) is a very reliable method. Method. The characteristics of the surgical anatomy of 1023 RLN have been summarized on the basis of intraoperative palpability, running down, branching variations, thickness, and laryngeal entry site. Results. Palpation was helpful in 81.4% (833/1023), proved false positive in 8.2% (84/1023), and in 10.4% (106/1023) it was of no help in the exact localization. Definitive RLN palsy was experienced in 0.78% of all cases (8/1023), while transient paresis was encountered in 1.2% (12/1023). Only a moderately strong stochastic correlation could be found between RLN palsies and those nerves which were nonpalpable and atypical, which showed the joint occurrence of being both thinner than normal and branching already before the plane of the inferior thyroid artery (Cramer's associate coefficient, C = 0.383). Conclusion. Palpation alone cannot substitute visualization and proper surgical dissection of the nerve. © 2008 Wiley Periodicals, Inc. Head Neck, 2009 [source] A picture says more than a thousand words: Structural insights into hepatitis C virus translation initiation,HEPATOLOGY, Issue 6 2006Pantxika Bellecave Ph.D. Protein synthesis in mammalian cells requires initiation factor eIF3, a ,750-kilodalton complex that controls assembly of 40S ribosomal subunits on messenger RNAs (mRNAs) bearing either a 5,-cap or an internal ribosome entry site (IRES). Cryoelectron microscopy reconstructions show that eIF3, a five-lobed particle, interacts with the hepatitis C virus (HCV) IRES RNA and the 5,-cap binding complex eIF4F via the same domain. Detailed modeling of eIF3 and eIF4F onto the 40S ribosomal subunit reveals that eIF3 uses eIF4F or the HCV IRES in structurally similar ways to position the mRNA strand near the exit site of 40S, promoting initiation complex assembly. [source] Immune enhancement of nitroreductase-induced cytotoxicity: Studies using a bicistronic adenovirus vectorINTERNATIONAL JOURNAL OF CANCER, Issue 1 2003Nicola K. Green Abstract The nitroreductase (NR)/CB1954 enzyme prodrug system has given promising results in preclinical studies and is currently being assessed in phase I clinical trials. It is well established that there is an immune component to the bystander effect observed with other systems such as thymidine kinase and cytosine deaminase; however, such an effect has not previously been described using NR. We have preliminary data suggesting an immune bystander effect with NR to further examine these effects and their potential enhancement by cytokines, an adenoviral vector containing CMV-NR, an internal ribosome entry site (IRES) and the gene for murine GM-CSF (mGM-CSF) was constructed. The NR-GM-CSF virus was validated in 2 experimental models and demonstrated increased therapeutic efficacy in the MC26 murine colorectal tumour model. These data illustrate that the combination of suicide gene therapy using NR and CB1954 with immune stimulation via GM-CSF gives an improved response compared to either modality alone and suggests that the immune component of this response may be beneficial in combating unresectable, metastatic disease and preventing tumour recurrence. © 2002 Wiley-Liss, Inc. [source] Central venous access for haemodialysis: prospective evaluation of possible complicationsJOURNAL OF CLINICAL NURSING, Issue 2 2007Denise De Andrade PhD Aims and objectives., The combination of chronic renal insufficiency and haemodialysis represents a challenge for health professionals. Chronic renal insufficiency patients undergoing haemodialysis treatment through a temporary double-lumen catheter were prospectively studied in order to identify the type and frequency of local and systemic complications. Methods., A six-month period was established with a view to the inclusion of new cases. Data were acquired through interviews, clinical assessment and patient records, and entered into a Microsoft Excel database through a double entry system and exported to the Statistical Package Social Sciences software. Sixty-four patients were evaluated prospectively, of which thirty-eight (59.4%) were men and 35 (54.7%) required catheter insertion for immediate treatment. During the study period, 145 catheters were inserted, ranging from 1 to 7 implants per patient, 29 (45.3%) were single insertions and 127 (87.6%) catheters were inserted into the jugular vein. The catheters were left in place for an average of 30 days. Results., Forty-one (64%) presented inadequate functioning, after about 26 days. A febrile state occurred in 24 (37.5%) patients after 34 days, secretion at the catheter entry site in 27 (42.2% after 26 days and bloodstream infection was encountered in 34(53%) after 34 days. Of the 61 blood culture samples, thirty (49%) were positive for Staphylococcus aureus that was the microorganism most frequently isolated. Conclusion., The findings indicate worrying aspects such as the catheters permanence time, exposing patients to different complications, including infection. Furthermore, inadequate catheter functioning leads to inefficient haemodialysis treatment. Relevance to clinical practice., Knowledge about complications allows for systematic care planning, prevention and control actions. [source] Cell specific internal translation efficiency of Epstein,Barr virus present in solid organ transplant patientsJOURNAL OF MEDICAL VIROLOGY, Issue 5 2007Åsa Isaksson Abstract The U leader exon in the 5, untranslated region of the Epstein,Barr virus nuclear antigen 1 (EBNA1) gene contains an internal ribosome entry site, the EBNA internal ribosome entry segment (IRES), which promotes cap-independent translation and increases the expression level of the EBNA1 protein. It was previously reported that immunosuppressed organ transplanted patients showed an alternatively spliced EBNA1 transcript, excluding the EBNA IRES element. To further investigate the function of the EBNA IRES, sequence analysis of the EBNA IRES mRNA was performed in samples from seven organ transplant patients. Two nucleotide changes, G,,,A at position 67531 and C,,,U at position 67585 were found in the EBNA IRES mRNA, relative to the corresponding genomic Epstein,Barr virus (EBV) sequence in all patients. Moreover, the patient derived EBNA IRES mRNA was shown to differ from the IRES mRNA derived from the cell line B95.8 at position 67531 and from the cell lines Rael and P3HR1 at positions 67531 and 67585. cDNA from the various EBNA IRES sequences were cloned into bicistronic vectors, respectively, and used in transient transfection experiments in six human cell lines. The patient specific sequence significantly decreased the IRES activity in T-cells, while the base changes had no significant impact on the activity in B- or in epithelial cells. The genetic mechanisms behind EBV-associated diseases are complex, involving gene regulation by alternative promoters, alternative splicing, and translational control. The nucleotide changes in the patient specific EBNA IRES transcript and its influence on the translational activity, might illustrate new strategies utilised by the EBV to adapt to the immune control in patients with EBV associated diseases. J. Med. Virol. 79:573,581, 2007. © 2007 Wiley-Liss, Inc. [source] Possible involvement in oncogenesis of a single base mutation in an internal ribosome entry site of Epstein,Barr nuclear antigen 1 mRNAJOURNAL OF MEDICAL VIROLOGY, Issue 4 2004Rika Endo Abstract It has been reported recently that the U leader exon located within the 5, untranslated region of Epstein,Barr nuclear antigen 1 (EBNA1) gene contains an internal ribosome entry site (IRES) element. Sequence analysis of the U leader exon was undertaken in samples from 19 patients with infectious mononucleosis and 19 patients with lethal lymphoproliferative diseases and in 15 spontaneously established lymphoblastoid cell lines. The sequence was conserved except for a single base substitution (T-C) at position 67,585. Although the mutation was detected in only one case of infectious mononucleosis, it was found in more than half of the lethal lymphoproliferative diseases and all lymphoblastoid cell lines. The results suggest that a mutation in the IRES element affects EBNA1 gene expression at the translational level and provides Epstein,Barr virus (EBV)-infected cells with a growth advantage, leading to immortalization of cells in vitro and to the development of lethal lymphoproliferative diseases in vivo. J. Med. Virol. 72:630,634, 2004. © 2004 Wiley-Liss, Inc. [source] Developmental strategy of the endoparasite Xenos vesparum (strepsiptera, Insecta): Host invasion and elusion of its defense reactionsJOURNAL OF MORPHOLOGY, Issue 7 2007Fabio Manfredini Abstract To successfully complete its endoparasitic development, the strepsipteran Xenos vesparum needs to elude the defense mechanisms of its host, the wasp Polistes dominulus. SEM and TEM observations after artificial infections allow us to outline the steps of this intimate host,parasite association. Triungulins, the mobile 1st instar larvae of this parasite, are able to "softly" overcome structural barriers of the larval wasp (cuticle and epidermis) without any traumatic reaction at the entry site, to reach the hemocoel where they settle. The parasite molts 48 h later to a 2nd instar larva, which moves away from the 1st instar exuvium, molts twice more without ecdysis (a feature unique to Strepsiptera) and pupates, if male, or develops into a neotenic female. Host encapsulation involves the abandoned 1st larval exuvium, but not the living parasite. In contrast to the usual process of encapsulation, it occurs only 48 h after host invasion or later, and without any melanization. In further experiments, first, we verified Xenos vesparum's ability to reinfect an already parasitized wasp larva. Second, 2nd instar larvae implanted in a new host did not evoke any response by hemocytes. Third, we tested the efficiency of host defense mechanisms by implanting nylon filaments in control larval wasps, excluding any effect due the dynamic behavior of a living parasite; within a few minutes, we observed the beginning of a typical melanotic encapsulation plus an initial melanization in the wound site. We conclude that the immune response of the wasp is manipulated by the parasite, which is able to delay and redirect encapsulation towards a pseudo-target, the exuvia of triungulins, and to elude hemocyte attack through an active suppression of the immune defense and/or a passive avoidance of encapsulation by peculiar surface chemical properties. J. Morphol., 2007 © 2007 Wiley-Liss, Inc. [source] A novel inducible tyrosine kinase receptor to regulate signal transduction and neurite outgrowthJOURNAL OF NEUROSCIENCE RESEARCH, Issue 12 2009Ronald W. Alfa Abstract Nervous system growth factor gene delivery can promote axonal growth and prevent cell death in animal models of CNS trauma and neurodegenerative diseases. The ability to regulate growth factor expression or signaling pathways downstream from growth factor receptors remains a desirable goal for in vivo gene transfer. To achieve precise pharmacological modulation of neurotrophin activity, we have generated a chimeric trkA receptor (ItrkA) by fusing the entire intracellular domain of the trkA high-affinity NGF receptor to two intracellular, modified FK506 binding domains for the synthetic small molecule dimerization ligand AP20187. Rat PC12 cells were transduced with lentiviral vectors containing ItrkA and green fluorescent protein (GFP; via an internal ribosome entry site). Treatment of ItrkA-expressing PC12 cells with AP20187 induced neurite outgrowth and differentiation in a time- and dose-dependent fashion, with a half-maximal response at a concentration of 1 nM AP20187. Seventy percent of cells responded to AP20187 by day 3. Western blots demonstrated that AP20187 treatment resulted in phosphorylation of Erk1/2 and Akt in ItrkA-transduced PC12 cells but not in nontransduced, naïve cells. Phosphorylation levels were comparable to levels obtained with 50 ng/ml nerve growth factor (NGF). In addition, ItrkA lentiviral transduction of primary E15 dorsal root ganglion neurons significantly increased neurite growth three- to fourfold in the presence of AP20187 compared with control GFP transduced and naïve neurons. These results demonstrate that small ligand-induced dimerization of the intracellular domain of trkA can efficiently simulate the biological activity of NGF and provide a means to regulate intracellular neurotrophin receptor signaling. © 2009 Wiley-Liss, Inc. [source] Normal nigrostriatal innervation but dopamine dysfunction in mice carrying hypomorphic tyrosine hydroxylase allelesJOURNAL OF NEUROSCIENCE RESEARCH, Issue 4 2003Susanna Althini Abstract We investigated the use of the mouse tyrosine hydroxylase (TH) gene to drive knock-in constructs in catecholaminergic neurons. Two targeting constructs representing truncated forms of either of the BMP receptors ALK-2 or BMPR-II preceded by an internal ribosome entry site (IRES) were introduced into the 3, untranslated region of TH. An frt-flanked neomycin-resistance (neor) cassette was placed in the 3, end of the targeting constructs. Mice homozygous for the knock-in alleles showed various degrees of hypokinetic behavior, depending mainly on whether the neor cassette was removed. In situ hybridization and immunohistochemistry showed that TH mRNA and protein were variously down-regulated in these mouse strains. Reduced levels of dopamine and noradrenalin were found in several brain areas. However, number and morphology of neurons in substantia nigra and their projections to striatum appeared normal in the neor -positive TH hypomorphic mice as examined by markers for L-aromatic amino acid decarboxylase and the dopamine transporter. Elimination of the neor cassette from the knock-in alleles partially restored TH and dopamine levels. The present neor -positive TH hypomorphic mice show that nigrostriatal innervation develops independently of TH and should find use as a model for conditions of reduced catecholamine synthesis, as seen in, for example, L-dihydroxyphenylalanine-responsive dystonia/infantile parkinsonism. © 2003 Wiley-Liss, Inc. [source] Effects of adenoviral-mediated coexpression of bone morphogenetic protein-7 and insulin-like growth factor-1 on human periodontal ligament cellsJOURNAL OF PERIODONTAL RESEARCH, Issue 4 2010L. Yang Yang L, Zhang Y, Dong R, Peng L, Liu X, Wang Y, Cheng X. Effects of adenoviral-mediated coexpression of bone morphogenetic protein-7 and insulin-like growth factor-1 on human periodontal ligament cells. J Periodont Res 2010; 45: 532,540. © 2010 John Wiley & Sons A/S Background and Objective:, Bone morphogenetic protein-7 (BMP-7) and insulin-like growth factor-1 (IGF-1) are important in periodontal reconstruction. However, their synergistic effect in periodontal regeneration by gene delivery has not been reported. In this study, gene delivery of these two growth factors to human periodontal ligament cells (hPDLCs) was examined for its effects on cell proliferation and differentiation. Material and Methods:, Recombinant adenoviruses containing both human BMP-7 and IGF-1 cDNA created by introducing the internal ribosome entry site (IRES) sequence were used to transfer the genes into hPDLCs. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and cell cycle analysis were used to observe their effects on cell proliferation, while alkaline phosphatase activity measurement, RT-PCR and in vivo tests were conducted to investigate their effects on cell differentiation. Results:, The proliferation of hPDLCs transduced by adenoviruses coexpressing BMP-7 and IGF-1 was suppressed while their differentiation ability was enhanced. There was a synergism of BMP-7 and IGF-1 in up-regulating alkaline phosphatase activity and mRNA levels of collagen type I and Runx2. Implantation in vivo with scaffolds illustrated that the transduced cells exhibited osteogenic differentiation and formed bone-like structures. Conclusion:, The combined delivery of BMP-7 and IGF-1 genes using an IRES-based strategy synergistically enhanced differentiation of hPDLCs. It is suggested that this could be a new potential method in gene therapy for periodontal reconstruction. [source] Hepatitis A virus (HAV) proteinase 3C inhibits HAV IRES-dependent translation and cleaves the polypyrimidine tract-binding proteinJOURNAL OF VIRAL HEPATITIS, Issue 9 2010T. Kanda Summary., Hepatitis A virus (HAV) infection is still an important issue worldwide. A distinct set of viruses encode proteins that enhance viral cap-independent translation initiation driven by an internal ribosome entry site (IRES) and suppress cap-dependent host translation. Unlike cytolytic picornaviruses, replication of HAV does not cause host cell shut off, and it has been questioned whether HAV proteins interfere with its own and/or host translation. HAV proteins were coexpressed in Huh-7 cells with reporter genes whose translation was initiated by either cap-dependent or cap-independent mechanisms. Among the proteins tested, HAV proteinase 3C suppressed viral IRES-dependent translation. Furthermore, 3C cleaved the polypyrimidine tract-binding protein (PTB) whose interaction with the HAV IRES had been demonstrated previously. The combined results suggest that 3C-mediated cleavage of PTB might be involved in down-regulation of viral translation to give way to subsequent viral genome replication. [source] Correlation between translation efficiency and outcome of combination therapy in chronic hepatitis C genotype 3JOURNAL OF VIRAL HEPATITIS, Issue 2 2006A. Yasmeen Summary., Combination therapy with interferon- , (IFN- ,) and ribavirin (RBV) in chronic hepatitis C demonstrates the best responses against hepatitis C virus (HCV) of genotype 3. Still, it has proven to be ineffective in 20,30% of patients infected with this genotype. In the present study, we analysed the translation efficiency mediated by the internal ribosome entry site (IRES) region in HCV genotype 3 genomes isolated from sustained responders (SR) and non-responders (NR), assuming that this may influence the outcome of treatment. Pretreatment isolates of genotype 3 from 22 individuals (15 SR, seven NR) were selected for such analyses. The IRES region [nucleotide (nt) 1,407] was cloned into a dual luciferase vector and IRES activity assessed following transfection into various cell lines. Low relative translation efficiency was observed for IRES elements derived from SR patients, whereas those of NR patients showed significantly greater translation efficiency (29.7 ± 13 vs 69.4 ± 22; P < 0.01). Subsequently, the effect of IFN- , plus RBV on IRES-driven translation in vitro was determined. A greater suppressive effect was observed on IRES activity isolated from seven SR patients, when compared with seven NR patients. In conclusion, IRES efficiency in vitro correlated with treatment response for HCV genotype 3. Further studies are warranted to investigate whether IRES efficiency in vitro, or sequence motifs associated with IRES efficiency, will be worthwhile to explore as prognostic tools for other HCV genotypes in the treatment of chronic HCV infection. [source] Introduction of NS5A mutations enables subgenomic HCV replicon derived from chimpanzee-infectious HC-J4 isolate to replicate efficiently in Huh-7 cellsJOURNAL OF VIRAL HEPATITIS, Issue 5 2004S. Maekawa Summary., Hepatitis C virus (HCV) subgenomic replicon has been reported to replicate efficiently and continuously in human hepatoma Huh-7 cells. To extend the previous results to other isolated HCV clones, we constructed another HCV replicon from HC-J4, one of chimpanzee-infectious HCV clones. An HCV replicon derived from HC-J4 (RpJ4) consists of HCV-5, untranslated region, neomycin phosphotransferase gene, the encephalomyocarditis virus internal ribosomal entry site, HCV nonstructural region, NS3 to NS5B, and HCV-3, untranslated region. The adaptive mutations known to be required for HCV-Con1 replicon were introduced in RpJ4 replicon, aa.(amino acids number according to HC-J4) 2197 serine to proline, deletion of serine at aa.2201, and aa.2204 serine to isoleucine (RpJ4-S2197P, RpJ4-S22001del, and RpJ4-S2204I). RpJ4/ISDR mutant and RpJ4-S2201del/ISDR mutant were also constructed by introducing six amino acid mutations into the interferon sensitivity determining region (ISDR). After transfection into Huh-7 cells and G418 selection, RpJ4 and RpJ4/ISDR mutants did not produce any colony. In contrast, G418-resistant cells were transduced efficiently by RpJ4-S2197P, RpJ4-S2204I, RpJ4-S2201del and RpJ4-S2201del/ISDR mutant, with the RpJ4-S2201del/ISDR mutant being most efficient. Hence the HCV replicon derived from HC-J4 can replicate efficiently following the introduction of adaptive mutations into the upstream region of ISDR. Moreover, additional introduction of mutations into ISDR further enhanced its replication. These findings demonstrate that the genetic structure of the NS5A domain is critical in HCV replications. [source] Single nucleotide insertion in the 5,-untranslated region of hepatitis C virus with clearance of the viral RNA in a liver transplant recipient during acute hepatitis B virus superinfectionLIVER INTERNATIONAL, Issue 1 2002Consolato Sergi Abstract: Hepatitis C virus (HCV) infection is an important etiology in patients undergoing orthotopic liver transplantation (OLT) world-wide. Antiviral therapy-related clearance of HCV RNA may occur both in patients with chronic HCV infection and in transplanted patients for HCV-related liver cirrhosis, but the role of the 5,-untranslated region (UTR) of HCV containing the internal ribosome entry site (IRES), which directs the translation of the viral open reading frame has not hitherto been evaluated. We studied the 5,-UTR in an HCV-infected recipient of a liver graft that showed spontaneous clearance of HCV RNA during an acute hepatitis B virus (HBV) superinfection. Sequencing of the 5,-UTR of HCV showed a nucleotide A insertion at position 193 of the IRES. [source] Role of adult living donor liver transplantation in patients with hepatitis CLIVER TRANSPLANTATION, Issue 10C 2003Gregory T. Everson Key points 1. Living donor liver transplantation (LDLT) is an option for patients with end-stage liver disease or hepatoma caused by chronic hepatitis C. 2. Reports from some, but not all, transplant centers indicate that hepatitis C may recur earlier, recurrence may be more severe, and graft loss caused by recurrent hepatitis C may be more frequent in LDLT compared with cadaveric transplantation. 3. Several unique characteristics of LDLT (versus cadaveric transplantation) may favor severe recurrence of hepatitis C. These include an increase in genetic similarity between donor and recipient, higher degree of HLA matching, greater systemic bioavailability of immunosuppressive agent, and hepatic regeneration. 4. Hepatic regeneration may promote the acceleration and severity of recurrent hepatitis C by enhancement of hepatitis C viral uptake by hepatocytes through stimulation of the low-density lipoprotein receptor and increase in activity of the internal ribosomal entry site. [source] Inactivation of the decay pathway initiated at an internal site by RNase E promotes poly(A)-dependent degradation of the rpsO mRNA in Escherichia coliMOLECULAR MICROBIOLOGY, Issue 4 2003Paulo E. Marujo Summary In Escherichia coli, RNA degradation is mediated by endonucleolytic processes, frequently mediated by RNase E, and also by a poly(A)-dependent mechanism. The dominant pathway of decay of the rpsO transcripts is initiated by an RNase E cleavage occurring at a preferential site named M2. We demonstrate that mutations which prevent this cleavage slow down degradation by RNase E. All these mutations reduce the single-stranded character of nucleotides surrounding the cleavage site. Moreover, we identify two other cleavage sites which probably account for the slow RNase E-mediated degradation of the mutated mRNAs. Failure to stabilize the rpsO transcript by appending a 5, hairpin indicates that RNase E is not recruited by the 5, end of mRNA. The fact that nucleotide substitutions which prevent cleavage at M2 facilitate the poly(A)-dependent degradation of the rpsO transcripts suggest an interplay between the two mechanisms of decay. In the discussion, we speculate ,that ,a ,structural ,feature ,located ,in ,the ,vicinity of M2 could be an internal degradosome entry site promoting both RNase E cleavages and poly(A)-dependent degradation of the rpsO mRNA. We also discuss the role of poly(A)-dependent decay in mRNA metabolism. [source] Venous Occlusion of the Access Vein in Patients Referred for Lead Extraction:PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 8 2003Influence of Patient, Lead Characteristics The aim of this study was to determine the effect of patient and lead characteristics on occlusion of the access vein in pacemaker and ICD patients. Contrast venography of the access vein was obtained in 89 patients (17 patients with an ICD) scheduled for lead extraction. The indication for extraction was infection in 57 patients (systemic infection in 9) and lead malfunction in 32 patients. In 6 of the 89 patients, leads were introduced in both the right and left subpectoral area, resulting in a total of 95 venous entry sites. In 22 of these entry sites one lead was present, in 61 two leads, in 11 three, and in 1 four leads. The vessel patency was graded open or occluded. Occlusion of the subclavian vein occurred in four (13%) patients with lead malfunction versus 18 (32%) patients with infection (P = 0.07). In patients with systemic infection, 5 of 9 showed venous occlusion (P = 0.01 when compared to patients with malfunction, odds ratio 8.75, 95% confidence interval 1.21,64.11). Considered per entry site, the incidence of occlusion was 7 of 22 with one lead present, 17 of 61 with two leads, 0 of 11 with three leads, and 0 of 1 with four leads (P = 0.13). No patient had a superior vena caval occlusion. Patients with systemic infection have an increased risk of occlusion of the access vein. On the contrary, the study found no support for the concept that the risk of venous occlusion increases with a higher number of leads present. (PACE 2003; 26:1649,1652) [source] (634) Reliability and Clinical Utility of an Implanted Intraspinal Catheter Used in the Treatment of Spasticity and PainPAIN MEDICINE, Issue 2 2000Article first published online: 25 DEC 200 Authors: Elliot Krames, Pacific Pain Treatment Center; Iva Chapple, Carolina Pain Center Objectives: To examine the performance and reliability of a redesigned implantable intrathecal catheter. Materials: A total of 212 catheters were implanted in 202 patients in this 22-center, prospective study of an implantable catheter/pump system used to deliver intrathecal drugs for the treatment of pain and spasticity. Along with physician assessments of each use, the rates of common catheter complications (dislodgements, disconnections, fractures, and kinks) experienced during the study were analyzed in relation to implant conditions (catheter entry site, tip position, and anchoring method). Results: A cumulative study of 3112.8 months of patient experience (average: 15.4 months; range: 0 to 30.2 months per catheter) revealed an overall catheter-caused complication rate of 0.3% per patient month. Physician assessments were favorable, with 89% rating this catheter as better than previously used intraspinal catheters. A measure of catheter survival estimates (Kaplan-Meier) at 9 months was 89% including all complications. Comparison of data relating to implant techniques demonstrated a variety of catheter implant techniques (entry, positioning, anchoring) with no correlation between any one technique and the common complications. Conclusions: Performance data and physician assessments indicate that this catheter is an improvement over the previously available catheter. [source] Local Recurrence of Breast Cancer after Skin-Sparing Mastectomy Following Core Needle Biopsy: Case Reports and Review of the LiteratureTHE BREAST JOURNAL, Issue 3 2006Juan Luis Uriburu MD Abstract: The latest advances in diagnostic and therapeutic procedures for breast cancer have provided valuable technological breakthroughs. Yet the long-term consequences of these modern methods are still quite unclear. Such is the case for stereotactic or ultrasound-guided histologic needle biopsy and skin-sparing mastectomy. We report on three patients who presented with multicentric breast cancer diagnosed by stereotactic needle biopsy and treated by skin-sparing mastectomy. All three patients developed recurrence at the core needle entry site. Records of 58 patients with breast cancer who were treated by skin-sparing mastectomy followed by immediate reconstruction (with transverse rectus abdominis muscle [TRAM] flap or tissue expander) at the Breast Diseases Division of Buenos Aires British Hospital between December 1999 and December 2003 were reviewed retrospectively. Eleven of these patients were diagnosed by histologic needle biopsy. The mean follow-up was 28 months (range 5,60 months). Three (skin or subcutaneous) local recurrences at the needle entry site, diagnosed in a mean time of 23.6 months (16, 22, and 23 months), were reported. The three patients underwent complete resection with clear margins, radiation therapy to the "neobreast," and tamoxifen. All three patients are disease free with a mean postrecurrence follow-up of 24.3 months (30, 23, and 22 months). Based on the evidence of displacement of tumor cells and the potential nonresection of such tumor seeding at the time of skin-sparing mastectomy, as well as the poor probability of postoperative radiation therapy, we recommend surgical resection of the needle biopsy tract, including the dermal entry site, at the time of mastectomy. [source] Implementation in Australia of molecular diagnostic techniques for the rapid detection of foot and mouth disease virusAUSTRALIAN VETERINARY JOURNAL, Issue 7 2004DB BOYLE Objective To evaluate and implement rapid molecular diagnostic techniques for the detection of foot and mouth disease virus (FMDV) suitable for use in Australia. Design Two PCR TaqMan assays targeted to the FMDV internal ribosome entry site or the 3D polymerase coding region for the rapid detection of FMDV were evaluated using non-infectious materials to determine the test most appropriate for implementation as part of Australia's national preparedness for the rapid detection and diagnosis of FMD outbreaks. Results Two published tests (PCR TaqMan assays targeted to the FMDV IRES region or the FMDV 3D polymerase coding region) were evaluated for their ability to detect FMDV genetic material in non-infectious FMDV ELISA antigen stocks held at Australian Animal Health Laboratory. Both tests were able to detect FMDV genetic material from strains O1 Manisa, O-3039, A22, A24, A Malaysia, C, Asia 1 and SAT 1, 2 and 3. With the exception of Asia 1, the TaqMan assay targeted to the FMD 3D polymerase coding region had Ct values equal to or lower than for the TaqMan assay targeted to the IRES region suggesting that this test may provide broader serotype detection and sensitivity. However, the TaqMan assay directed to the FMDV IRES is the only one to date to have undergone substantial evaluation using clinical samples collected during an outbreak. The greatest differences observed were for O-3039, SAT 1, and 3. Conclusion Given the ease of setting up both tests, AAHL currently runs both tests on highly suspect FMD investigations to provide independent confirmation of the absence of FMDV because the tests are focused on two independent regions of the FMDV genome. These tests add substantially to Australia's preparedness for FMD diagnosis complementing the already well-established virus isolation and antigen capture ELISA tests for index case diagnosis of FMD in Australia. [source] A novel synthetic mammalian promoter derived from an internal ribosome entry siteBIOTECHNOLOGY & BIOENGINEERING, Issue 4 2006Shizuka Hartenbach Abstract Introduction of specific mutations into a synthetic internal ribosome entry site (IRESGTX) derived from the GTX homeodomain protein revealed additional transcriptional activity. This novel synthetic PGTX promoter exhibited consensus core promoter modules such as the initiator (Inr) and the partial downstream promoter elements (DPE) and mediated high-level expression of a variety of transgenes including the human vascular endothelial growth factor 121 (VEGF121), the human placental secreted alkaline phosphatase (SEAP), and the Bacillus stearothermophilus -derived secreted ,-amylase (SAMY) in Chinese hamster ovary cells (CHO-K1) and a variety of other mammalian and human cell lines. The spacing between Inr and DPE modules was found to be critical for promoter performance since introduction of a single nucleotide (resulting in PGTX2) doubled the SEAP expression levels in CHO-K1. PGTX2 reached near 70% of PSV40 -driven expression levels and outperformed constitutive phosphoglycerate kinase (PPGK) and human ubiquitin C (PhUBC) promoters in CHO-K1. Also, PGTX2 was successfully engineered for macrolide-inducible transgene expression. Owing to its size of only 182 bp, PGTX2 is one of the smallest eukaryotic promoters. Although PGTX2 was found to be a potent promoter, it retained its IRESGTX -specific translation-initiation capacity. Synthetic DNAs, which combine multiple activities in a most compact sequence format may foster advances in therapeutic engineering of mammalian cells. © 2006 Wiley Periodicals, Inc. [source] Long-term pericardial catheterization is associated with minimum foreign-body responseCATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 2 2007Carlo R. Bartoli BS Abstract Objectives: The goals of this study were to assess the feasibility and to characterize the foreign-body response of a long-term catheter in the pericardium. Background: Long-term access to the normal pericardial space provides opportunities for diagnostic sampling and therapeutic intervention. Methods: After thoracotomy, in 7 anesthetized canines, the pericardium was opened and a 5 French silicone vascular access catheter was advanced 10 cm into the pericardial sac toward the apex of the heart. A hydraulic coronary balloon occluder was implanted (N = 6). Pericardium was sealed with Prolene suture. Catheters were tunneled to the nape of the neck, attached to a subcutaneous vascular access port, and buried in the fascia. Animals underwent multiple experimental coronary artery occlusions across months. At sacrifice, we assessed the histopathological response of pericardium and epicardium to chronically indwelling silicone catheters. Results: Post-mortem examinations were performed at 213 days post-operatively (mean, range = 96,413, N = 6), with one animal maintained for longer-term study. At sacrifice, all catheters were bidirectionally patent and completely mobile in the pericardium without evidence of tissue overgrowth around the intrapericardial segment. Adhesion tissue was found only at the site of catheter entry through the pericardium. Microscopic histopathological examination at catheter entry site, surrounding pericardium, and myocardium revealed minimum chronic inflammation. Conclusions: This subcutaneous system provides dependable, chronic access to the normal pericardial space for drug delivery and sampling. The presence of a chronic silicone catheter in the pericardium does not precipitate clinically significant pathologic changes even after repeated ischemic events. © 2007 Wiley-Liss, Inc. [source] Periorbital ecchymosis as a sign of perforating injury of the globeCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 2 2005Seyed M Ghazi-Nouri MRCOphth Abstract The distinction between penetrating eye injury with retained intraocular foreign body and perforating globe injuries is not always easy clinically. The case is presented of a 25-year-old man who sustained a perforating eye injury that was through a clear self-sealing corneal entry site and had no conjunctival or periorbital injury. He had periorbital ecchymosis on presentation suggesting that the globe had been perforated with resulting retro-orbital blood tracking to the periorbital region. This sign would not be expected had the foreign body remained intraocular. The management options of these cases are discussed. [source] Bacterial colonization of stimulation electrode wires in patients undergoing temporary sacral nerve stimulationCOLORECTAL DISEASE, Issue 2 2010T. Dudding Abstract Objective, In patients undergoing sacral nerve stimulation (SNS), a temporary percutaneous stimulation wire is often used to assess the clinical response to therapy prior to chronic stimulation. The aim of this study was to evaluate the incidence of bacterial colonization of screening wires and risk of clinical infection in patients undergoing prolonged temporary SNS screening. Method, Data were collected prospectively on a consecutive series of patients undergoing temporary SNS for bowel dysfunction. Procedures were performed using a standardized percutaneous technique with a single shot of either co-amoxyclav 1.2 g or cefuroxime 1.5 g given intravenously on induction. Adherent polyurethane dressings were applied to secure the wire. At the end of the screening period the wire and dressings were removed, the skin entry site was cleaned using an alcohol wipe and the wire removed via an aseptic technique. The distal tip of the wire was then cut and sent for culture. Results, Thirteen wires were removed at a median of 21 (range 16,29) days following insertion. There were no signs of local or systemic infection. Seven of the thirteen wires (54%) were found to have deep bacterial colonization. The commonest organisms isolated were staphylococcus species. There was no correlation between the length of time the lead had been implanted and the incidence of bacterial colonization. Conclusion, Bacterial colonization of the temporary stimulation wire is common but appears to be associated with a low risk of clinical infection. A single peri-operative dose of antibiotics does not appear to prevent colonization. [source] Contact-dependent aggregation of functional Ca2+ channels, synaptic vesicles and postsynaptic receptors in active zones of a neuromuscular junctionEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2001David A. DiGregorio Abstract To examine whether Ca2+ channels aggregate in a contact-dependent manner, we characterized the distribution of synaptic vesicles and postsynaptic receptors, and compared it to the location of Ca2+ entry sites, in a Xenopus laevis nerve-muscle coculture preparation using a localized Ca2+ detection method. The majority (75%) of Ca2+ entry sites at spontaneously formed nerve,muscle contacts were associated with enhanced immunofluorescence to the synaptic vesicle protein, SV2. In contrast, only 11% of recorded sites without Ca2+ transients exhibited significant SV2 immunofluorescence. When comparing the spatial distribution of synaptic markers with that of Ca2+ entry sites, we found that the majority of Ca2+ entry sites (61%) were associated with both enhanced SV2 immunofluorescence and R-BTX fluorescence, thereby identifying putative neurotransmitter release sites where Ca2+ channels, synaptic vesicles and postsynaptic receptors are colocalized. Using polystyrene beads coated with a heparin binding protein known to mediate in vitro postsynaptic receptor clustering, we show that the location of Ca2+ domains was associated with enhanced SV2 immunofluorescence at neurite-to-bead contacts. We conclude that the localization of functional Ca2+ channels to putative active zones follows a contact-dependent signalling mechanism similar to that known to mediate vesicle aggregation and AChR clustering. [source] Venous Occlusion of the Access Vein in Patients Referred for Lead Extraction:PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 8 2003Influence of Patient, Lead Characteristics The aim of this study was to determine the effect of patient and lead characteristics on occlusion of the access vein in pacemaker and ICD patients. Contrast venography of the access vein was obtained in 89 patients (17 patients with an ICD) scheduled for lead extraction. The indication for extraction was infection in 57 patients (systemic infection in 9) and lead malfunction in 32 patients. In 6 of the 89 patients, leads were introduced in both the right and left subpectoral area, resulting in a total of 95 venous entry sites. In 22 of these entry sites one lead was present, in 61 two leads, in 11 three, and in 1 four leads. The vessel patency was graded open or occluded. Occlusion of the subclavian vein occurred in four (13%) patients with lead malfunction versus 18 (32%) patients with infection (P = 0.07). In patients with systemic infection, 5 of 9 showed venous occlusion (P = 0.01 when compared to patients with malfunction, odds ratio 8.75, 95% confidence interval 1.21,64.11). Considered per entry site, the incidence of occlusion was 7 of 22 with one lead present, 17 of 61 with two leads, 0 of 11 with three leads, and 0 of 1 with four leads (P = 0.13). No patient had a superior vena caval occlusion. Patients with systemic infection have an increased risk of occlusion of the access vein. On the contrary, the study found no support for the concept that the risk of venous occlusion increases with a higher number of leads present. (PACE 2003; 26:1649,1652) [source] Crystallization and preliminary X-ray diffraction analysis of the MIF4G domain of DAP5ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 1 2010Filipp Frank Death-associated protein 5 (DAP5) is a member of the eIF4G family of scaffolding proteins that mediate cap-independent translation initiation by recruiting the translational machinery to internal ribosomal entry sites (IRESs) on mRNA. The MIF4G domain of DAP5 directly interacts with the eukaryotic initiation factors eIF4A and eIF3 and enhances the translation of several viral and cellular IRESs. Here, the crystallization and preliminary X-ray diffraction analysis of the MIF4G domain of DAP5 is presented. [source] Novel CNBP- and La-based translation control systems for mammalian cellsBIOTECHNOLOGY & BIOENGINEERING, Issue 1 2003Stefan Schlatter Abstract Throughout the development of Xenopus, production of ribosomal proteins (rp) is regulated at the translational level. Translation control is mediated by a terminal oligopyrimidine element (TOP) present in the 5, untranslated region (UTR) of rp -encoding mRNAs. TOP elements adopt a specific secondary structure that prevents ribosome-binding and translation-initiation of rp -encoding mRNAs. However, binding of CNBP (cellular nucleic acid binding protein) or La proteins to the TOP hairpin structure abolishes the TOP-mediated transcription block and induces rp production. Based on the specific CNBP-TOP/La-TOP interactions we have designed a translation control system (TCS) for conditional as well as adjustable translation of desired transgene mRNAs in mammalian cells. The generic TCS configuration consists of a plasmid encoding CNBP or La under control of the tetracycline-responsive expression system (TETOFF) and a target expression vector containing a TOP module between a constitutive PSV40 promoter and the human model product gene SEAP (human secreted alkaline phosphatase) (PSV40 -TOP- SEAP -pA). The TCS technology showed excellent SEAP regulation profiles in transgenic Chinese hamster ovary (CHO) cells. Alternatively to CNBP and La, TOP-mediated translation control can also be adjusted by artificial phosphorothioate anti-TOP oligodeoxynucleotides. Confocal laser-scanning microscopy demonstrated cellular uptake of FITC-labeled oligodeoxynucleotides and their localization in perinuclear organelles within 24 hours. Besides their TOP-based translation-controlling capacity, CNBP and La were also shown to increase cap-independent translation from polioviral internal ribosomal entry sites (IRES) and La alone to boost cap-dependent translation initiation. CNBP and La exemplify for the first time the potential of RNA-binding proteins to exert translation control of desired transgenes and to increase heterologous protein production in mammalian cells. We expect both of these assets to advance current gene therapy and biopharmaceutical manufacturing strategies. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 1,12, 2003. [source] 3315: Transconjunctival sutureless 20GACTA OPHTHALMOLOGICA, Issue 2010CJ POURNARAS Purpose To evaluate a trocar system that allows the use of the regular 20-gauge vitrectomy instruments for a transconjunctival sutureless surgery for the treatment of various surgically treated vitreo-retinal pathologies. Methods The 20-gauge trocar system uses a 10° self-sealing tunneled incision made with trocars introduced with a inserter blade of 0.9 mm diameter. Incisions are radially made at 3.5 mm from the limbus and tunnels are made limbus-parallel. Evaluation of the surgical procedure, sclerotomies closure by OCT, anatomical and visual outcomes in various vitreoretinal pathologies treated in current vitreoretinal practice. Results Postoperative patient comfort and less eye inflammation are provided by the sutureless technique, allthough small conjunctival hemorrhage caused by the grasping forceps used to hold the eye during the insertion of the trocars may occur. The 20-gauge trocar system using 10° self-sealing tunneled incision remains very stable in the eye even during peripheral vitrectomy with indentation and they also decrease the surgical induced trauma at the entry sites. The use of nonflexible instruments, the same as in 20-gauge conventional vitrectomy, provides easy access to the entire periphery.thus the system can be used in almost all vitreoretinal surgeries. It allows the use of phragmatome and is easy to work even with 5,000 centistokes silicone oil. Conclusion In the era of sutureless surgeries, the 20-gauge trocar system is a safe, comfortable, convinient with current instrumentation and less expensive alternative to 25- and 23-gauge vitrectomy. [source] | |||||||||||||||||||||||||