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1.
Br J Cancer ; 110(5): 1221-7, 2014 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-24496456

RESUMO

BACKGROUND: The epidermal growth factor receptor (EGFR) is overexpressed in colorectal cancer (CRC), and is correlated with poor prognosis, making it an attractive target for monoclonal antibody (mAb) therapy. A component of the therapeutic efficacy of IgG1 mAbs is their stimulation of antibody-dependent cellular cytotoxicity (ADCC) by natural killer (NK) cells bearing the CD16 receptor. As NK cells are functionally impaired in cancer patients and may be further compromised upon chemotherapy, it is crucial to assess whether immunotherapeutic strategies aimed at further enhancing ADCC are viable. METHODS: CRC patients before, during and after chemotherapy were immunophenotyped by flow cytometry for major white blood cell populations. ADCC-independent NK cell functionality was assessed in cytotoxicity assays against K562 cells. ADCC-dependent killing of EGFR(+) A431 cancer cells by NK cells was measured with a degranulation assay where ADCC was induced by GA201, an anti-EGFR mAb glyco-engineered to enhance ADCC. RESULTS: Here, we confirm the observation that NK cells in cancer patients are dysfunctional. However, GA201 was able to induce robust NK cell-dependent cytotoxicity in CRC patient NK cells, effectively overcoming their impairment. CONCLUSIONS: These findings support the evaluation of the therapeutic potential of GA201 in combination with chemotherapy in CRC patients.


Assuntos
Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Monoclonais Humanizados/farmacologia , Neoplasias Colorretais/imunologia , Neoplasias Colorretais/terapia , Receptores ErbB/imunologia , Glicoproteínas/imunologia , Glicoproteínas/farmacologia , Células Matadoras Naturais/imunologia , Citotoxicidade Celular Dependente de Anticorpos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Estudos de Casos e Controles , Linhagem Celular Tumoral , Neoplasias Colorretais/sangue , Neoplasias Colorretais/tratamento farmacológico , Proteínas Ligadas por GPI/imunologia , Humanos , Imunoglobulina G/imunologia , Células K562 , Receptores de IgG/imunologia
2.
Transpl Infect Dis ; 16(1): 90-7, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24256514

RESUMO

INTRODUCTION: Advances in autologous hematopoietic stem cell transplantation (HSCT) over the past 20 years may have had an impact on the morbidity and mortality associated with infections post transplant. PATIENTS AND METHODS: We sought to retrospectively analyze the epidemiology of the first episode of bacterial, fungal, viral, or parasitic infections 0-30 days post transplant in a cohort of 320 children and adolescents who underwent autologous HSCT in a single institution, between 1990 and 2009 for solid tumors or lymphoma, and in 65 children transplanted for acute leukemia during the same period. RESULTS: Infections occurred in 66 (21%) patients with solid tumors or lymphoma. Bacterial infections occurred in 33 (10%) including bacteremia in 23 (7%), and viral infections in 34 (11%) patients. Gram-positive bacterial infections were more prevalent than gram-negative bacterial infections (P = 0.03). Infections caused by fungal or parasitic pathogens were uncommon. The decade when transplant was performed (1990-1999 vs. 2000-2009) had no impact on the incidence of bacterial (P = 0.41) or viral (P = 0.47) infection. Between 1990 and 1999, a total of 60 (92%) children were transplanted for leukemia, and 5 (8%) in the 2000-2009 period (P < 0.0001). Infections occurred in 32 (49%) patients. Bacterial (P = 0.004), candidal (P = 0.003), and herpes simplex viral (P = 0.03) infections were more common in patients transplanted for leukemia. In patients transplanted for leukemia, 3 deaths occurred attributed to infection, all before 2000. CONCLUSION: Changes in epidemiology of infection are likely a result of decline in autologous transplantation for childhood leukemia in the recent era. Autologous transplantation for solid tumors or lymphoma was not associated with mortality from early infections at our institution.


Assuntos
Infecções Bacterianas/epidemiologia , Transplante de Células-Tronco Hematopoéticas , Leucemia/terapia , Linfoma/terapia , Micoses/epidemiologia , Doenças Parasitárias/epidemiologia , Viroses/epidemiologia , Adolescente , Infecções Bacterianas/microbiologia , Candidíase/epidemiologia , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Herpes Simples/epidemiologia , Humanos , Incidência , Lactente , Masculino , Micoses/microbiologia , Neoplasias/terapia , Doenças Parasitárias/parasitologia , Estudos Retrospectivos , Transplante Autólogo , Viroses/virologia , Adulto Jovem
3.
Radiography (Lond) ; 30(2): 474-482, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38217933

RESUMO

INTRODUCTION: Medical imaging is arguably the most technologically advanced field in healthcare, encompassing a range of technologies which continually evolve as computing power and human knowledge expand. Artificial Intelligence (AI) is the next frontier which medical imaging is pioneering. The rapid development and implementation of AI has the potential to revolutionise healthcare, however, to do so, staff must be competent and confident in its application, hence AI readiness is an important precursor to AI adoption. Research to ascertain the best way to deliver this AI-enabled healthcare training is in its infancy. The aim of this scoping review is to compare existing studies which investigate and evaluate the efficacy of AI educational interventions for medical imaging staff. METHODS: Following the creation of a search strategy and keyword searches, screening was conducted to determine study eligibility. This consisted of a title and abstract scan, then subsequently a full-text review. Articles were included if they were empirical studies wherein an educational intervention on AI for medical imaging staff was created, delivered, and evaluated. RESULTS: Of the initial 1309 records returned, n = 5 (∼0.4 %) of studies met the eligibility criteria of the review. The curricula and delivery in each of the five studies shared similar aims and a 'flipped classroom' delivery was the most utilised method. However, the depth of content covered in the curricula of each varied and measured outcomes differed greatly. CONCLUSION: The findings of this review will provide insights into the evaluation of existing AI educational interventions, which will be valuable when planning AI education for healthcare staff. IMPLICATIONS FOR PRACTICE: This review highlights the need for standardised and comprehensive AI training programs for imaging staff.


Assuntos
Inteligência Artificial , Diagnóstico por Imagem , Humanos , Escolaridade , Radiografia , Currículo
4.
Radiography (Lond) ; 30(4): 1158-1166, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38848642

RESUMO

INTRODUCTION: With the use of expert consensus a digital training tool was developed which proved useful when teaching radiographers how to interpret chest images. The training tool included A) a search strategy and B) an educational video programme to communicate the search strategies using eye tracking technology. METHODS: A multi-reader multi-case study was undertaken to assess the effectiveness of a training tool and study day. The interventions were designed to cover a range of potential pathological presentations. Participants, physiotherapists and nurse practitioners working at a cardiothoracic Intensive Care Unit (ICU), were asked to interpret 20 chest images at the beginning of the study and following access to each intervention. Participants received access to the training tool at different times for a period of 4-6 weeks. A study day was then be provided to all participants and interpretations of a different dataset were completed by all. Each participant was asked to complete a questionnaire to gain perceptions of the training provided. RESULTS: Twenty-eight participants interpreted a total of 1680 chest radiographs. Improvements in specificity were noted across the participants. Sensitivity fell in both groups following both training interventions. CONCLUSION: Face to face learning and digital components are potentially useful in professional development and revision in chest x-ray interpretation for non-medical healthcare professionals working in an ICU setting. IMPLICATIONS FOR PRACTICE: The training tool and study day may be useful as image interpretation revision aids or to accompany formal methods of education.


Assuntos
Competência Clínica , Radiografia Torácica , Humanos , Pessoal de Saúde/educação , Inquéritos e Questionários , Sensibilidade e Especificidade , Feminino , Masculino
5.
Radiography (Lond) ; 29 Suppl 1: S128-S136, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36907794

RESUMO

INTRODUCTION: Radiotherapy is a major component of cancer care and treatment is delivered almost exclusively by therapeutic radiographers/radiation therapists (RTTs). Numerous government and professional guidance publications have recommended a person-centred approach to healthcare through communication and collaboration between professionals, agencies, and users. With approximately half of patients undergoing radical radiotherapy experiencing some degree of anxiety and distress, RTTs are uniquely placed as frontline cancer professionals to engage with patients regarding their experience. This review seeks to map the available evidence of patient reported views of their experience of being treated by RTTs and any impact, this treatment had on the patient's frame of mind or perception of treatment. METHODS: In line with the principles of the Preferred Reporting Items for Systematic and Meta-Analyses (PRISMA) systematic review methodology, a review of relevant literature was conducted. Electronic databases MEDLINE, PROQUEST, EMBASE and CINAHL were searched. RESULTS: Nine hundred and eighty-eight articles were identified. Twelve papers were included in the final review. CONCLUSION: Increased time with, and continuity of RTTs during treatment has a positive influence on patients' perspectives of RTTs. A positive patient perspective of their engagement with RTTs can be a strong predictor of overall satisfaction in radiotherapy. IMPLICATIONS FOR PRACTICE: RTTs should not underestimate the impact of their supportive role in guiding patients through treatment. A standardised method for integrating patients' experience and engagement with RTTs is lacking. Further RTT led research is required in this area.


Assuntos
Participação do Paciente , Radioterapia (Especialidade) , Humanos , Pacientes , Pessoal Técnico de Saúde , Comunicação
6.
Radiography (Lond) ; 27(2): 505-511, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33257162

RESUMO

INTRODUCTION: Eye tracking technology, checklists and search strategies have been demonstrated as useful aids in image interpretation. A training tool was developed, by the research team, which included these features. This study aimed to evaluate the effect of the training tool on participant image interpretation performance. METHODS: The study was carried out with reporting radiographers who had either commenced training in chest image interpretation (n = 12) or were trained in musculoskeletal image interpretation (n = 23) (total n = 35). Participants were allocated to a control or intervention group. Participants completed an initial assessment at recruitment and re-attended nine months later for a follow-up assessment. The intervention group were given unlimited access to a digital training tool. During assessments participants interpreted 20 chest images whilst using eye tracking technology (total of 1400 images were interpreted). A confidence level was obtained from participants on their diagnosis and a questionnaire, to obtain demographic data, was completed following the assessment. RESULTS: Improvements were seen in the confidence of intervention group participants (p < 0.05). False Positive (FP) scores decreased for both the control and intervention group (p < 0.05), this decrease was from 4.20 to 3.20 for the control group and from 5.87 to 3.27 for the intervention group. True Negative (TN) scores increased, from 5.13 to 6.73 for the intervention group (p < 0.05). Mean decision time decreased for both the control and intervention group. CONCLUSION: The tool led to positive effects on participant performance and could be a useful aid in chest image interpretation learning. IMPLICATIONS FOR PRACTICE: Improvements in performance were observed with a digital tool. The tool could improve image interpretation methods and training.


Assuntos
Competência Clínica , Tecnologia de Rastreamento Ocular , Pessoal Técnico de Saúde , Lista de Checagem , Humanos , Tecnologia
7.
Water Res ; 43(9): 2531-9, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19371919

RESUMO

The objective of this study was to examine the feasibility of using a two-step, fully biological and sustainable strategy for the treatment of carbohydrate rich wastes. The primary step in this strategy involves the application of thermostable enzymes produced by the thermophilic, aerobic fungus, Talaromyces emersonii, to carbohydrate wastes producing a liquid hydrolysate discharged at elevated temperatures. To assess the potential of thermophilic treatment of this hydrolysate, a comparative study of thermophilic and mesophilic digestion of four sugar rich thermozyme hydrolysate waste streams was conducted by operating two high rate upflow anaerobic hybrid reactors (UAHR) at 37 degrees C (R1) and 55 degrees C (R2). The operational performance of both reactors was monitored from start-up by assessing COD removal efficiencies, volatile fatty acid (VFA) discharge and % methane of the biogas produced. Rapid start-up of both R1 and R2 was achieved on an influent composed of the typical sugar components of the organic fraction of municipal solid waste (OFMSW). Both reactors were subsequently challenged in terms of volumetric loading rate (VLR) and it was found that a VLR of 9 gCOD l(-1)d(-1) at a hydraulic retention time (HRT) of 1 day severely affected the thermophilic reactor with instability characterised by a build up of volatile fatty acid (VFA) intermediates in the effluent. The influent to both reactors was changed to a simple glucose and sucrose-based influent supplied at a VLR of 4.5 gCOD l(-1)d(-1) and HRT of 2 days prior to the introduction of thermozyme hydrolysates. Four unique thermozyme hydrolysates were subsequently supplied to the reactors, each for a period of 10 HRTs. The applied hydrolysates were derived from apple pulp, bread, carob powder and cardboard, all of which were successfully and comparably converted by both reactors. The % total carbohydrate removal by both reactors was monitored during the application of the sugar rich thermozyme hydrolysates. This approach offers a sustainable technology for the treatment of carbohydrate rich wastes and highlights the potential of these wastes as substrates for the generation of second-generation biofuels.


Assuntos
Reatores Biológicos/microbiologia , Carboidratos , Fungos/enzimologia , Resíduos , Anaerobiose , Biomassa , Estabilidade Enzimática , Ácidos Graxos Voláteis/biossíntese , Temperatura Alta
8.
Insect Mol Biol ; 17(2): 125-35, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18353102

RESUMO

Three CYP6Z genes are linked to a major pyrethroid resistance locus in the mosquito Anopheles gambiae. We have expressed CYP6Z2 in Escherichia coli and produced a structural model in order to examine its role in detoxification. E. coli membranes co-expressing CYP6Z2 and An. gambiae P450 reductase (AgCPR) catalysed the dealkylation of benzyloxyresorufin with kinetic parameters K(m) = 0.13 microM; K(cat) = 1.5 min(-1). The IC(50) values of a wide range of compounds were measured. Pyrethroids cypermethrin and permethrin produced low IC(50) values, but were not metabolized. Plant flavanoids were the most potent inhibitors. Several compounds were shown to be substrates, suggesting that CYP6Z2 has broad substrate specificity and plays an important chemo-protective role during the herbivorous phase of the life-cycle.


Assuntos
Anopheles/enzimologia , Inibidores das Enzimas do Citocromo P-450 , Sistema Enzimático do Citocromo P-450/metabolismo , Insetos Vetores/enzimologia , Inseticidas/farmacologia , Piretrinas/farmacologia , Laranja de Acridina , Sequência de Aminoácidos , Animais , Anopheles/genética , Clonagem Molecular , Sistema Enzimático do Citocromo P-450/genética , DNA/química , DNA/genética , Escherichia coli/enzimologia , Escherichia coli/genética , Concentração Inibidora 50 , Insetos Vetores/genética , Resistência a Inseticidas , Inseticidas/farmacocinética , Isoenzimas , Modelos Moleculares , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Piretrinas/farmacocinética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Alinhamento de Sequência
10.
Ir Med J ; 101(4): 102-6, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18557510

RESUMO

For the purpose of this study twenty cases, involving the deaths of Irish nationals while abroad, were examined. The aims of the report were 1) to observe whether autopsy guidelines are being implemented by countries throughout the world investigating the deaths of foreign citizens, particularly Irish nationals, 2) to compare/contrast the cause(s) of death established in Ireland and the countries where the deaths occurred and 3) where appropriate, suggest improvements to the current system. The results revealed that where a complete autopsy is not performed then the chance of forming a correct cause of death, or any cause of death, decreases from 100% to 0%. The standard of autopsies on foreign nationals varies from country to country and within countries. Currently there are many different autopsy procedure guidelines available. The time may have come to formulate one universal set of guidelines that are to be implemented worldwide.


Assuntos
Autopsia/normas , Internacionalidade , Autopsia/métodos , Humanos , Irlanda , Guias de Prática Clínica como Assunto
11.
Radiography (Lond) ; 24(2): 159-164, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29605114

RESUMO

INTRODUCTION: Time delays and errors exist which lead to delays in patient care and misdiagnosis. Reporting clinicians follow guidance to form their own search strategy. However, little research has tested these training guides. With the use of eye tracking technology and expert input we developed a digital training platform to be used in chest image interpretation learning. METHODS: Two sections of a digital training platform were planned and developed; A) a search strategy training tool to assist reporters during their interpretation of images, and B) an educational tool to communicate the search strategies of expert viewers to trainees by using eye tracking technology. RESULTS: A digital training platform for use in chest image interpretation was created based on evidence within the literature, expert input and two search strategies previously used in clinical practice. Images and diagrams, aiding translation of the platform content, were incorporated where possible. The platform is structured to allow the chest image interpretation process to be clear, concise and methodical. CONCLUSION: A search strategy was incorporated within the tool to investigate its use, with the possibility that it could be recommended as an evidence based approach for use by reporting clinicians. Eye tracking, a checklist and voice recordings have been combined to form a multi-dimensional learning tool, which has never been used in chest image interpretation learning before. The training platform for use in chest image interpretation learning has been designed, created and digitised. Future work will establish the efficacy of the developed approaches.


Assuntos
Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Radiografia Torácica , Radiologia/educação , Lista de Checagem , Erros de Diagnóstico/prevenção & controle , Movimentos Oculares , Humanos , Capacitação em Serviço , Interface Usuário-Computador , Gravação em Vídeo
12.
J Clin Invest ; 106(9): 1105-13, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11067863

RESUMO

Apolipoprotein J/clusterin (apoJ/clusterin), an intriguing protein with unknown function, is induced in myocarditis and numerous other inflammatory injuries. To test its ability to modify myosin-induced autoimmune myocarditis, we generated apoJ-deficient mice. ApoJ-deficient and wild-type mice exhibited similar initial onset of myocarditis, as evidenced by the induction of two early markers of the T cell-mediated immune response, MHC-II and TNF receptor p55. Furthermore, autoantibodies against the primary antigen cardiac myosin were induced to the same extent. Although the same proportion of challenged animals exhibited some degree of inflammatory infiltrate, inflammation was more severe in apoJ-deficient animals. Inflammatory lesions were more diffuse and extensive in apoJ-deficient mice, particularly in females. In marked contrast to wild-type animals, the development of a strong generalized secondary response against cardiac antigens in apoJ-deficient mice was predictive of severe myocarditis. Wild-type mice with a strong Ab response to secondary antigens appeared to be protected from severe inflammation. After resolution of inflammation, apoJ-deficient, but not wild-type, mice exhibited cardiac function impairment and severe myocardial scarring. These results suggest that apoJ limits progression of autoimmune myocarditis and protects the heart from postinflammatory tissue destruction.


Assuntos
Doenças Autoimunes/etiologia , Glicoproteínas/fisiologia , Chaperonas Moleculares , Miocardite/etiologia , Animais , Antígenos CD/biossíntese , Autoanticorpos/biossíntese , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Sequência de Bases , Clusterina , Primers do DNA/genética , Feminino , Glicoproteínas/deficiência , Glicoproteínas/genética , Antígenos de Histocompatibilidade Classe II/biossíntese , Masculino , Camundongos , Camundongos Knockout , Miocardite/imunologia , Miocardite/patologia , Miosinas/imunologia , Receptores do Fator de Necrose Tumoral/biossíntese , Receptores Tipo I de Fatores de Necrose Tumoral , Linfócitos T/imunologia
13.
Neuropeptides ; 41(4): 195-205, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17576012

RESUMO

We have generated mouse transgenic lines using yeast artificial chromosome (YAC) technology which demonstrate expression from the human NK1 receptor (NK1R) locus. We introduced a 380 kb fragment encompassing the human NK1R gene and flanking regions which we hoped would recapitulate the expected endogenous expression of the human gene. To visualise this expression the NK1 locus co-expresses the green fluorescence protein gene (GFP) under the control of an internal ribosome entry site (IRES) sequence. We have generated five mouse lines that express the human NK1 receptor gene with and without the marker gene. All the lines incorporating the marker gene appear to exhibit the same expression pattern in analysis of selected anatomical regions throughout the mouse. The lack of a human specific NK1R antibody determined that we could not distinguish between expression of the transgene and endogenous NK1R. Our analysis has shown transgene expression in brain areas known to express NK1R in human such as the hippocampus and caudate putamen. The majority of these cells were also positive for GFP fluorescence. These transgenic lines may prove a good pre-clinical model as drugs can be addressed against both the human receptor and modulators of its expression in vivo.


Assuntos
Camundongos Transgênicos , Receptores da Neurocinina-1/metabolismo , Transgenes , Animais , Cromossomos Artificiais , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Hipocampo/citologia , Hipocampo/metabolismo , Humanos , Camundongos , Receptores da Neurocinina-1/genética , Medula Espinal/citologia , Medula Espinal/metabolismo
14.
Radiography (Lond) ; 23(4): 350-357, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28965900

RESUMO

OBJECTIVES: This systematic review aimed to determine the strength of evidence available in the literature on the effect of training to develop the skills required by radiographers to interpret plain radiography chest images. KEY FINDINGS: Thirteen articles feature within the review. Sample size varied from one reporting radiographer to 148 radiography students/experienced radiographers. The quality of the articles achieved a mean score of 7.5/10, indicating the evidence is strong and the quality of studies in this field is high. Investigative approaches included audit of participants' performance in clinical practice post formal training, evaluation of informal training and the impact of short feedback sessions on performance. CONCLUSION: All studies demonstrated positive attributions on user performance. Using a combination of training techniques can help maximise learning and accommodate those with different preferred learning types.


Assuntos
Pessoal Técnico de Saúde/educação , Competência Clínica , Radiografia Torácica , Radiologia/educação , Tecnologia Radiológica/educação , Humanos
15.
Clin Vaccine Immunol ; 24(9)2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28724524

RESUMO

The pneumococcal enzyme-linked immunosorbent assay (ELISA) reference standard serum, lot 89SF, had been in use since 1990 and was replaced with a new reference standard serum, 007sp, in 2013. This serum was generated under an FDA-approved clinical protocol where 278 adult volunteers were immunized with the 23-valent unconjugated polysaccharide vaccine Pneumovax II and a unit of blood was obtained twice within 120 days following immunization. Pooled serum was prepared from the plasma, filled at 6 ml per vial, and lyophilized. Five independent laboratories participated in bridging the serotype-specific IgG assignments of 89SF to 007sp to establish equivalent reference values for 13 pneumococcal capsular serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 23F) using the WHO reference ELISA. A subsequent follow-up study established equivalent reference values for an additional seven serotypes (8, 10A, 11A, 12F, 15B, 22F, 33F). In this study, three laboratories assigned weight-based IgG concentrations in micrograms per milliliter of serum to 007sp for four additional serotypes: 2, 9N, 17F, and 20A. This study completes the assignment of serotypes for 89SF to 007sp. In addition, the IgG antibody assignments for a 12-member WHO quality control (QC) serum panel were extended to cover the four additional serotypes. Agreement was excellent, with a concordance correlation coefficient (rc ) of >0.996 when values from each laboratory were compared to the assigned values for the 12 WHO QC sera. The 007sp preparation has replaced 89SF as the pneumococcal reference standard. Sufficient quantities of 007sp are projected to be available for the next 25 years.

17.
Nucleic Acids Res ; 28(10): 2128-34, 2000 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-10773082

RESUMO

The synthesis and triplex stabilizing properties of oligodeoxyribonucleotides functionalized at the 5'- and/or 3'-termini with a naphthalene diimide-based (NDI) intercalator is described. The NDI intercalator was prepared in a single step from the corresponding dianhydride and was attached to the 5'-terminus of an oligodeoxyribonucleotide following a reverse coupling procedure. The DMT protecting group was removed and the sequence phosphitylated to generate the phosphoramidite derivative on the 5'-terminus of the support-bound oligodeoxyribonucleotide. The NDI intercalator with a free hydroxyl was then added in the presence of tetrazole. Attachment of the NDI to the 3'-terminus relied upon a tethered amino group that could be functionalized first with the naphthalene dianhydride, which was subsequently converted to the diimide. Using both procedures, an oligonucleo-tide conjugate was prepared having the NDI intercalator at both the 5'- and 3'-termini. Thermal denaturation studies were used to determine the remarkable gain in stability for triplexes formed when the NDI-conjugated oligonucleotide was present as the third strand in the complex.


Assuntos
DNA/química , Imidas/síntese química , Substâncias Intercalantes/síntese química , Conformação de Ácido Nucleico , Oligodesoxirribonucleotídeos/química , Sequência de Bases , Cromatografia Líquida de Alta Pressão , Imidas/química , Indicadores e Reagentes , Substâncias Intercalantes/química , Naftalenos , Ressonância Magnética Nuclear Biomolecular , Fenantrolinas , Termodinâmica
18.
Nucleic Acids Res ; 28(17): 3316-22, 2000 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-10954600

RESUMO

Two analog uridine triphosphates tethering additional functionality, one a primary amino group and the second a mercapto group, were prepared and tested for their compatibility with in vitro RNA selection procedures. 5-(3-Aminopropyl)uridine triphosphate (UNH(2)) as a uridine substitute was a more effective substrate for T7 RNA polymerase than 5-(2-mercaptoethyl)uridine triphosphate (USH). However, both functioned in transcription assays of 100 nt templates to generate RNA transcripts in quantities sufficient to initiate RNA selection procedures. Transcription of RNA pools with T7 RNA polymerase and UNH(2) or USH occurred with efficiencies of 43 and 29%, respectively, of the values obtained for native UTP transcription. In addition, the transcribed RNA containing roughly 25% UNH(2) residues exhibited better substrate properties for SuperScript(TM) II RNase H reverse transcriptase than did RNA transcripts containing approximately 25% of the USH analog. With either analog, both transcription and reverse transcription proceeded with high fidelity for insertion of the analog residue.


Assuntos
Transcrição Gênica , Uridina/análogos & derivados , Uridina/metabolismo , Sequência de Bases , Cromatografia Líquida de Alta Pressão , RNA Polimerases Dirigidas por DNA/metabolismo , Cinética , Dados de Sequência Molecular , RNA/biossíntese , RNA/genética , RNA/metabolismo , DNA Polimerase Dirigida por RNA/metabolismo , Ribonuclease H/metabolismo , Especificidade por Substrato , Moldes Genéticos , Transcrição Gênica/genética , Uridina/química , Uridina Trifosfato/análogos & derivados , Uridina Trifosfato/síntese química , Uridina Trifosfato/química , Uridina Trifosfato/metabolismo , Proteínas Virais
19.
HLA ; 87(3): 141-52, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26880737

RESUMO

This study presents performance specifications of an in-house developed human leukocyte antigen (HLA) typing assay using next-generation sequencing (NGS) on the Illumina MiSeq platform. A total of 253 samples, previously characterized for HLA-A, -B, -C, -DRB1 and -DQB1 were included in this study, which were typed at high-resolution using a combination of Sanger sequencing, sequence-specific primer (SSP) and sequence-specific oligonucleotide probe (SSOP) technologies and recorded at the two-field level. Samples were selected with alleles that cover a high percentage of HLA specificities in each of five different race/ethnic groups: European, African-American, Asian Pacific Islander, Hispanic and Native American. Sequencing data were analyzed by two software programs, Omixon's target and GenDx's NGSengine. A number of metrics including allele balance, sensitivity, specificity, precision, accuracy and remaining ambiguity were assessed. Data analyzed by the two software systems are shown independently. The majority of alleles were identical in the exonic sequences (third field) with both programs for HLA-A, -B, -C and -DQB1 in 97.7% of allele determinations. Among the remaining discrepant genotype calls at least one of the analysis programs agreed with the reference typing. Upon additional manual analysis 100% of the 2530 alleles were concordant with the reference HLA genotypes; the remaining ambiguities did not exceed 0.8%. The results demonstrate the feasibility and significant benefit of HLA typing by NGS as this technology is highly accurate, eliminates virtually all ambiguities, provides complete sequencing information for the length of the HLA gene and forms the basis for utilizing a single methodology for HLA typing in the immunogenetics labs.


Assuntos
Alelos , Genótipo , Antígenos HLA/classificação , Antígenos HLA/genética , Teste de Histocompatibilidade/métodos , Primers do DNA/síntese química , Sondas de DNA/síntese química , Antígenos HLA/imunologia , Sequenciamento de Nucleotídeos em Larga Escala , Teste de Histocompatibilidade/instrumentação , Teste de Histocompatibilidade/normas , Humanos , Reação em Cadeia da Polimerase , Grupos Raciais , Sensibilidade e Especificidade , Análise de Sequência de DNA , Software
20.
J Mol Biol ; 202(4): 823-34, 1988 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-3172240

RESUMO

The ligation of a decadeoxynucleotide containing the EcoRI recognition site forms a series of multimers which appear to be curved based on observed anomalous gel migration in polyacrylamide gels. The degree of DNA curvature present in the recognition sequence, based upon the observed migration anomaly, can be altered by modifications to the purine functional groups at the 2- and 6-positions. Deletion of the guanine 2-amino group, occurring in the minor groove of the B-DNA helix, is most effective in increasing the observed DNA curvature. Conversely, the displacement of an amino group from the major groove to the minor groove eliminates curvature. DNA curvature is also modulated by the exocyclic group at the purine 6-position with decreasing curvature observed when changing the amino group to a carbonyl or proton substituent. Differences in the kinetic parameters characterizing the cleavage reaction by the endonuclease for many of the modified sequences are the result of modifications of functional groups in the major groove, which are likely to contact the endonuclease during catalysis. However, with two examples, significant decreases in the observed specificity constant (kcat/Km), characterizing the protein-nucleic acid interaction, cannot be easily explained in terms of such functional group contacts. It is more likely in these cases that the functional group modifications affect the efficiency of the endonuclease-DNA interaction by modulation of the structure of the double-stranded DNA helix. With both examples, modifications have been made to minor groove substituents. The extent of DNA curvature is increased significantly for one and decreased for the other, compared with that observed for the native recognition site. The results suggest that curvature of the DNA helix axis is an intrinsic property of the d(GAATTC) sequence which helps to optimize the protein-nucleic acid interactions observed for the EcoRI restriction endonuclease.


Assuntos
DNA , Conformação de Ácido Nucleico , Sequência de Bases , DNA/metabolismo , Desoxirribonuclease EcoRI/metabolismo , Eletroforese em Gel de Poliacrilamida , Cinética , Oligodesoxirribonucleotídeos/farmacocinética
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