93 research outputs found
Phase II trial of Modified Vaccinia Ankara (MVA) virus expressing 5T4 and high dose Interleukin-2 (IL-2) in patients with metastatic renal cell carcinoma
<p>Abstract</p> <p>Background</p> <p>Interleukin-2 (IL-2) induces durable objective responses in a small cohort of patients with metastatic renal cell carcinoma (RCC) but the antigen(s) responsible for tumor rejection are not known. 5T4 is a non-secreted membrane glycoprotein expressed on clear cell and papillary RCCs. A modified vaccinia virus Ankara (MVA) encoding 5T4 was tested in combination with high-dose IL-2 to determine the safety, objective response rate and effect on humoral and cell-mediated immunity.</p> <p>Methods</p> <p>25 patients with metastatic RCC who qualified for IL-2 were eligible and received three immunizations every three weeks followed by IL-2 (600,000 IU/kg) after the second and third vaccinations. Blood was collected for analysis of humoral, effector and regulatory T cell responses.</p> <p>Results</p> <p>There were no serious vaccine-related adverse events. While no objective responses were observed, three patients (12%) were rendered disease-free after nephrectomy or resection of residual metastatic disease. Twelve patients (48%) had stable disease which was associated with improved median overall survival compared to patients with progressive disease (not reached vs. 28 months, p = 0.0261). All patients developed 5T4-specific antibody responses and 13 patients had an increase in 5T4-specific T cell responses. Although the baseline frequency of Tregs was elevated in all patients, those with stable disease showed a trend toward increased effector CD8+ T cells and a decrease in Tregs.</p> <p>Conclusion</p> <p><b>V</b>accination with MVA-5T4 did not improve objective response rates of IL-2 therapy but did result in stable disease associated with an increase in the ratio of 5T4-specific effector to regulatory T cells in selected patients.</p> <p>Trial registration number</p> <p>ISRCTN83977250</p
Percutaneous vertebral compression fracture management with polyethylene mesh-contained morcelized allograft bone
Study design A comprehensive systematic review of the literature. Objectives To assess the modern literature on the use of polyethylene mesh-contained morcelized allograft (PMCMA) bone for spinal fusion and vertebral compression fracture management. Summary of background data There are presently no systematic reviews of PMCMA. Methods A systematic literature review was performed within three databases (OVID, PubMed, and Google Scholar) using the following keyword search terms: vertebroplasty, kyphoplasty, vertebral compression fracture, percutaneous, polyethylene mesh, and osteoporosis. Results The initial search identified 764 items, from which two pertinent technique-based articles were identified. There were no published scientific peer-reviewed or case series reporting the clinical results of this technique. The use of PMCMA in the management of vertebral compression fractures (VCFs) is similar to vertebroplasty and kyphoplasty. This novel, percutaneous system uses the properties of granular mechanics to establish a conforming, semirigid graft that is purportedly capable of withstanding physiologic loads. Discussion PMCMA is a novel percutaneous technology for the management of VCF and possibly for use as a conforming interbody graft. The available published literature lacks outcome data of the use of PMCMA. Careful, independent research is needed to assess the viability of this technology and its long-term results
Altered Patterns of Gene Expression Underlying the Enhanced Immunogenicity of Radiation-Attenuated Schistosomes
Schistosoma mansoni is a blood-dwelling parasitic worm that causes schistosomiasis in humans throughout Africa and parts of South America. A vaccine would enhance attempts to control and eradicate the disease that currently relies on treatment with a single drug. Although a manufactured vaccine has yet to generate high levels of protection, this can be achieved with infective parasite larvae that have been disabled by exposure to radiation. How these weakened parasites are able to induce protective immunity when normal parasites do not, is the question addressed by our experiments. We have used a technique of gene expression profiling to compare the patterns in normal and disabled parasites, over the period when they would trigger an immune response in the host. We found that only a handful of genes were differentially expressed, all of them diminished in the disabled parasite. However, a more sensitive technique to examine groups of genes revealed that those involved in nervous system and muscle function were depressed in the disabled parasites. We suggest that reduced mobility of these larvae permits them longer contact with the immune system, thus enabling a strong protective immune response to develop
CD4(+)CD25(+)FOXP3(+) Regulatory T Cells Suppress Anti-Tumor Immune Responses in Patients with Colorectal Cancer
BACKGROUND: A wealth of evidence obtained using mouse models indicates that CD4(+)CD25(+)FOXP3(+) regulatory T cells (Treg) maintain peripheral tolerance to self-antigens and also inhibit anti-tumor immune responses. To date there is limited information about CD4(+) T cell responses in patients with colorectal cancer (CRC). We set out to measure T cell responses to a tumor-associated antigen and examine whether Treg impinge on those anti-tumor immune responses in CRC patients. METHODOLOGY AND PRINCIPAL FINDINGS: Treg were identified and characterized as CD4(+)CD25(+)FOXP3(+) using flow cytometry. An increased frequency of Treg was demonstrated in both peripheral blood and mesenteric lymph nodes of patients with colorectal cancer (CRC) compared with either healthy controls or patients with inflammatory bowel disease (IBD). Depletion of Treg from peripheral blood mononuclear cells (PBMC) of CRC patients unmasked CD4(+) T cell responses, as observed by IFNγ release, to the tumor associated antigen 5T4, whereas no effect was observed in a healthy age-matched control group. CONCLUSIONS/SIGNIFICANCE: Collectively, these data demonstrate that Treg capable of inhibiting tumor associated antigen-specific immune responses are enriched in patients with CRC. These results support a rationale for manipulating Treg to enhance cancer immunotherapy
A Nitrile Hydratase in the Eukaryote Monosiga brevicollis
Bacterial nitrile hydratase (NHases) are important industrial catalysts and waste water remediation tools. In a global computational screening of conventional and metagenomic sequence data for NHases, we detected the two usually separated NHase subunits fused in one protein of the choanoflagellate Monosiga brevicollis, a recently sequenced unicellular model organism from the closest sister group of Metazoa. This is the first time that an NHase is found in eukaryotes and the first time it is observed as a fusion protein. The presence of an intron, subunit fusion and expressed sequence tags covering parts of the gene exclude contamination and suggest a functional gene. Phylogenetic analyses and genomic context imply a probable ancient horizontal gene transfer (HGT) from proteobacteria. The newly discovered NHase might open biotechnological routes due to its unconventional structure, its new type of host and its apparent integration into eukaryotic protein networks
Detection and quantitation of copy number variation in the voltage-gated sodium channel gene of the mosquito Culex quinquefasciatus
Insecticide resistance is typically associated with alterations to the insecticidal target-site or with gene expression variation at loci involved in insecticide detoxification. In some species copy number variation (CNV) of target site loci (e.g. the Ace-1 target site of carbamate insecticides) or detoxification genes has been implicated in the resistance phenotype. We show that field-collected Ugandan
Culex quinquefasciatus display CNV for the voltage-gated sodium channel gene (Vgsc), target-site of pyrethroid and organochlorine insecticides. In order to develop field-applicable diagnostics for Vgsc
CN, and as a prelude to investigating the possible association of CN with insecticide resistance, three
assays were compared for their accuracy in CN estimation in this species. The gold standard method is
droplet digital PCR (ddPCR), however, the hardware is prohibitively expensive for widespread utility.
Here, ddPCR was compared to quantitative PCR (qPCR) and pyrosequencing. Across all platforms, CNV was detected in ≈10% of mosquitoes, corresponding to three or four copies (per diploid genome).
ddPCR and qPCR-Std-curve yielded similar predictions for Vgsc CN, indicating that the qPCR protocol developed here can be applied as a diagnostic assay, facilitating monitoring of Vgsc CN in wild populations and the elucidation of association between the Vgsc CN and insecticide resistance
Lignosulfonic Acid Exhibits Broadly Anti-HIV-1 Activity – Potential as a Microbicide Candidate for the Prevention of HIV-1 Sexual Transmission
Some secondary metabolites from plants show to have potent inhibitory activities against microbial pathogens, such as human immunodeficiency virus (HIV), herpes simplex virus (HSV), Treponema pallidum, Neisseria gonorrhoeae, etc. Here we report that lignosulfonic acid (LSA), a polymeric lignin derivative, exhibits potent and broad activity against HIV-1 isolates of diverse subtypes including two North America strains and a number of Chinese clinical isolates values ranging from 21.4 to 633 nM. Distinct from other polyanions, LSA functions as an entry inhibitor with multiple targets on viral gp120 as well as on host receptor CD4 and co-receptors CCR5/CXCR4. LSA blocks viral entry as determined by time-of-drug addiction and cell-cell fusion assays. Moreover, LSA inhibits CD4-gp120 interaction by blocking the binding of antibodies specific for CD4-binding sites (CD4bs) and for the V3 loop of gp120. Similarly, LSA interacts with CCR5 and CXCR4 via its inhibition of specific anti-CCR5 and anti-CXCR4 antibodies, respectively. Interestingly, the combination of LSA with AZT and Nevirapine exhibits synergism in viral inhibition. For the purpose of microbicide development, LSA displays low in vitro cytotoxicity to human genital tract epithelial cells, does not stimulate NF-κB activation and has no significant up-regulation of IL-1α/β and IL-8 as compared with N-9. Lastly, LSA shows no adverse effect on the epithelial integrity and the junctional protein expression. Taken together, our findings suggest that LSA can be a potential candidate for tropical microbicide
Tinnitus referral pathways within the National Health Service in England: a survey of their perceived effectiveness among audiology staff
<p>Abstract</p> <p>Background</p> <p>In the UK, audiology services deliver the majority of tinnitus patient care, but not all patients experience the same level of service. In 2009, the Department of Health released a Good Practice Guide to inform commissioners about key aspects of a quality tinnitus service in order to promote equity of tinnitus patient care in UK primary care, audiology, and in specialist multi-disciplinary centres. The purpose of the present research was to evaluate utilisation and opinions on pathways for the referral of tinnitus patients to and from English Audiology Departments.</p> <p>Methods</p> <p>We surveyed all audiology staff engaged in providing tinnitus services across England. A 36-item questionnaire was mailed to 351 clinicians in all 163 National Health Service (NHS) Trusts identified as having a tinnitus service. 138 clinicians responded. The results presented here describe experiences and opinions of the current patient pathways to and from the audiology tinnitus service.</p> <p>Results</p> <p>The most common referral pathway was from general practice to a hospital-based Ear, Nose & Throat department and from there to a hospital-based audiology department (64%). Respondents considered the NHS tinnitus referral process to be generally effective (67%), but expressed needs for improving GP referral and patients' access to services. 'Open access' to the audiology clinic was rarely an option for patients (9%), nor was the opportunity to access specialist counselling provided by clinical psychology (35%). To decrease the number of inappropriate referrals, 40% of respondents called for greater awareness by referrers about the audiology tinnitus service.</p> <p>Conclusions</p> <p>Respondents in the present survey were generally satisfied with the tinnitus referral system. However, they highlighted some potential targets for service improvement including 1] faster and more appropriate referral from GPs, to be achieved through education on tinnitus referral criteria, 2] improved access to psychological services through audiologist training, and 3] ongoing support from tinnitus support groups, national charities, or open access to the tinnitus clinic for existing patients.</p
Crystal Structure of an Integron Gene Cassette-Associated Protein from Vibrio cholerae Identifies a Cationic Drug-Binding Module
Background
The direct isolation of integron gene cassettes from cultivated and environmental microbial sources allows an assessment of the impact of the integron/gene cassette system on the emergence of new phenotypes, such as drug resistance or virulence. A structural approach is being exploited to investigate the modularity and function of novel integron gene cassettes.
Methodology/Principal Findings
We report the 1.8 A crystal structure of Cass2, an integron-associated protein derived from an environmental V. cholerae. The structure defines a monomeric beta-barrel protein with a fold related to the effector-binding portion of AraC/XylS transcription activators. The closest homologs of Cass2 are multi-drug binding proteins, such as BmrR. Consistent with this, a binding pocket made up of hydrophobic residues and a single glutamate side chain is evident in Cass2, occupied in the crystal form by polyethylene glycol. Fluorescence assays demonstrate that Cass2 is capable of binding cationic drug compounds with submicromolar affinity. The Cass2 module possesses a protein interaction surface proximal to its drug-binding cavity with features homologous to those seen in multi-domain transcriptional regulators.
Conclusions/Significance
Genetic analysis identifies Cass2 to be representative of a larger family of independent effector-binding proteins associated with lateral gene transfer within Vibrio and closely-related species. We propose that the Cass2 family not only has capacity to form functional transcription regulator complexes, but represents possible evolutionary precursors to multi-domain regulators associated with cationic drug compounds.National Health and Medical Research Council (Australia) (NHMRC grant 488502)National Institutes of Health (U.S.) (Grant GM62414-0 )Ontario. Ministry of Revenue (Challenge Fund
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