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1.
Hered Cancer Clin Pract ; 21(1): 15, 2023 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-37568169

RESUMO

BACKGROUND: High-risk surveillance for patients with Li-Fraumeni syndrome (LFS) has shown a stage shift and improved overall survival, but is demanding. Our objective was to evaluate surveillance adherence in a population of patients with LFS presenting for high-risk care. METHODS: A retrospective analysis of surveillance adherence of adult patients with LFS at a single institution was performed. Adherence was defined by the duration from initial University of Virginia (UVA) LFS clinic visit to the time of first missed surveillance test. Two-sample t-tests and ANOVA tests were used to identify factors associated with duration of adherence. RESULTS: A total of 42 patients were evaluated in the UVA LFS clinic between 2017 and 2021. Of these, 21 patients met inclusion criteria. At the time of review, 6 patients (29%) were up to date with high-risk surveillance recommendations. The mean duration of adherence was 17 months. Female sex was found to be associated with longer duration of adherence (mean 21 mo vs. 3.5 mo for males, p = 0.02). A personal history or active diagnosis of cancer was also associated with increased adherence (p = 0.02). However, neither age (p = 0.89), geography (p = 0.84), or known family history of LFS (p = 0.08) were associated with duration of adherence. CONCLUSION: Female sex as well as a personal history of cancer were associated with longer duration of adherence to recommended high-risk surveillance among patients with LFS. Identification of barriers to surveillance will be essential moving forward to increase adherence and promote early detection of cancer, thereby reducing the morbidity and mortality of LFS.

2.
Sociol Health Illn ; 38(7): 1137-50, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27113456

RESUMO

In Vancouver, Canada, there has been a continuous shift in the policing of sex work away from arresting sex workers, which led to the implementation of a policing strategy that explicitly prioritised the safety of sex workers and continued to target sex workers' clients. We conducted semi-structured interviews with 26 cisgender and five transgender women street-based sex workers about their working conditions. Data were analysed thematically and by drawing on concepts of structural stigma and vulnerability. Our results indicated that despite police rhetoric of prioritising the safety of sex workers, participants were denied their citizenship rights for police protection by virtue of their 'risky' occupation and were thus responsiblised for sex work related violence. Our findings further suggest that sex workers' interactions with neighbourhood residents were predominantly shaped by a discourse of sex workers as a 'risky' presence in the urban landscape and police took swift action in removing sex workers in the case of complaints. This study highlights that intersecting regimes of stigmatisation and criminalisation continued to undermine sex workers citizenship rights to police protection and legal recourse and perpetuated labour conditions that render sex workers at increased risk for violence and poor health.


Assuntos
Polícia/legislação & jurisprudência , Trabalho Sexual/psicologia , Profissionais do Sexo/psicologia , Estigma Social , Adulto , Canadá , Feminino , Humanos , Masculino , Pesquisa Qualitativa , Delitos Sexuais/psicologia , Trabalho Sexual/legislação & jurisprudência , Profissionais do Sexo/legislação & jurisprudência
3.
J Trauma Dissociation ; 17(1): 67-80, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26211678

RESUMO

The present study investigates whether symptom severity can distinguish patients diagnosed with dissociative identity disorder and dissociative disorder not otherwise specified with a recent history of nonsuicidal self-injury (NSSI) and suicide attempts from those patients without recent self-harm. A total of 241 clinicians reported on recent history of patient NSSI and suicide attempts. Of these clinicians' patients, 221 completed dissociative, depressive, and posttraumatic stress disorder symptomatology measures. Baseline cross-sectional data from a naturalistic and prospective study of dissociative disorder patients receiving community treatment were utilized. Analyses evaluated dissociative, depressive, and posttraumatic stress disorder symptom severity as methods of classifying patients into NSSI and suicide attempt groupings. Results indicated that dissociation severity accurately classified patients into NSSI and suicidality groups, whereas depression severity accurately classified patients into NSSI groups. These findings point to dissociation and depression severity as important correlates of NSSI and suicidality in patients with dissociative disorders and have implications for self-harm prevention and treatment.


Assuntos
Transtorno Depressivo/classificação , Transtorno Depressivo/terapia , Transtornos Dissociativos/classificação , Transtornos Dissociativos/terapia , Comportamento Autodestrutivo/psicologia , Transtornos de Estresse Pós-Traumáticos/classificação , Transtornos de Estresse Pós-Traumáticos/terapia , Suicídio , Adolescente , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Índice de Gravidade de Doença
4.
PLoS Pathog ; 9(2): e1003149, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23459584

RESUMO

As one of the largest protein families, protein kinases (PKs) regulate nearly all processes within the cell and are considered important drug targets. Much research has been conducted on inhibitors for PKs, leading to a wealth of compounds that target PKs that have potential to be lead anthelmintic drugs. Identifying compounds that have already been developed to treat neglected tropical diseases is an attractive way to obtain lead compounds inexpensively that can be developed into much needed drugs, especially for use in developing countries. In this study, PKs from nematodes, hosts, and DrugBank were identified and classified into kinase families and subfamilies. Nematode proteins were placed into orthologous groups that span the phylum Nematoda. A minimal kinome for the phylum Nematoda was identified, and properties of the minimal kinome were explored. Orthologous groups from the minimal kinome were prioritized for experimental testing based on RNAi phenotype of the Caenorhabditis elegans ortholog, transcript expression over the life-cycle and anatomic expression patterns. Compounds linked to targets in DrugBank belonging to the same kinase families and subfamilies in the minimal nematode kinome were extracted. Thirty-five compounds were tested in the non-parasitic C. elegans and active compounds progressed to testing against nematode species with different modes of parasitism, the blood-feeding Haemonchus contortus and the filarial Brugia malayi. Eighteen compounds showed efficacy in C. elegans, and six compounds also showed efficacy in at least one of the parasitic species. Hypotheses regarding the pathway the compounds may target and their molecular mechanism for activity are discussed.


Assuntos
Anti-Helmínticos/farmacologia , Brugia Malayi/efeitos dos fármacos , Caenorhabditis elegans/efeitos dos fármacos , Haemonchus/efeitos dos fármacos , Proteínas Quinases/química , Animais , Brugia Malayi/genética , Caenorhabditis elegans/genética , Haemonchus/genética , Estrutura Molecular , Proteínas Quinases/genética , Interferência de RNA
5.
PLoS Pathog ; 9(8): e1003505, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23935495

RESUMO

Parasitic roundworm infections plague more than 2 billion people (1/3 of humanity) and cause drastic losses in crops and livestock. New anthelmintic drugs are urgently needed as new drug resistance and environmental concerns arise. A "chokepoint reaction" is defined as a reaction that either consumes a unique substrate or produces a unique product. A chokepoint analysis provides a systematic method of identifying novel potential drug targets. Chokepoint enzymes were identified in the genomes of 10 nematode species, and the intersection and union of all chokepoint enzymes were found. By studying and experimentally testing available compounds known to target proteins orthologous to nematode chokepoint proteins in public databases, this study uncovers features of chokepoints that make them successful drug targets. Chemogenomic screening was performed on drug-like compounds from public drug databases to find existing compounds that target homologs of nematode chokepoints. The compounds were prioritized based on chemical properties frequently found in successful drugs and were experimentally tested using Caenorhabditis elegans. Several drugs that are already known anthelmintic drugs and novel candidate targets were identified. Seven of the compounds were tested in Caenorhabditis elegans and three yielded a detrimental phenotype. One of these three drug-like compounds, Perhexiline, also yielded a deleterious effect in Haemonchus contortus and Onchocerca lienalis, two nematodes with divergent forms of parasitism. Perhexiline, known to affect the fatty acid oxidation pathway in mammals, caused a reduction in oxygen consumption rates in C. elegans and genome-wide gene expression profiles provided an additional confirmation of its mode of action. Computational modeling of Perhexiline and its target provided structural insights regarding its binding mode and specificity. Our lists of prioritized drug targets and drug-like compounds have potential to expedite the discovery of new anthelmintic drugs with broad-spectrum efficacy.


Assuntos
Anti-Helmínticos/uso terapêutico , Bases de Dados de Proteínas , Descoberta de Drogas , Proteínas de Helminto , Nematoides/metabolismo , Infecções por Nematoides , Animais , Drosophila melanogaster , Proteínas de Helminto/genética , Proteínas de Helminto/metabolismo , Humanos , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/genética , Infecções por Nematoides/metabolismo , Consumo de Oxigênio/efeitos dos fármacos
6.
Nucleic Acids Res ; 40(Database issue): D720-8, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22139919

RESUMO

Nematode.net (http://nematode.net) has been a publicly available resource for studying nematodes for over a decade. In the past 3 years, we reorganized Nematode.net to provide more user-friendly navigation through the site, a necessity due to the explosion of data from next-generation sequencing platforms. Organism-centric portals containing dynamically generated data are available for over 56 different nematode species. Next-generation data has been added to the various data-mining portals hosted, including NemaBLAST and NemaBrowse. The NemaPath metabolic pathway viewer builds associations using KOs, rather than ECs to provide more accurate and fine-grained descriptions of proteins. Two new features for data analysis and comparative genomics have been added to the site. NemaSNP enables the user to perform population genetics studies in various nematode populations using next-generation sequencing data. HelmCoP (Helminth Control and Prevention) as an independent component of Nematode.net provides an integrated resource for storage, annotation and comparative genomics of helminth genomes to aid in learning more about nematode genomes, as well as drug, pesticide, vaccine and drug target discovery. With this update, Nematode.net will continue to realize its original goal to disseminate diverse bioinformatic data sets and provide analysis tools to the broad scientific community in a useful and user-friendly manner.


Assuntos
Bases de Dados Genéticas , Sequenciamento de Nucleotídeos em Larga Escala , Nematoides/genética , Animais , Mineração de Dados , Genoma Helmíntico , Genômica , Redes e Vias Metabólicas , Nematoides/metabolismo , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Software
7.
Biochim Biophys Acta Gen Subj ; 1868(2): 130504, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37967728

RESUMO

The transgenic expression of rice triketone dioxygenase (TDO; also known as HIS1) can provide protection from triketone herbicides to susceptible dicot crops such as soybean. Triketones are phytotoxic inhibitors of plant hydroxyphenylpyruvate dioxygenases (HPPD). The TDO gene codes for an iron/2-oxoglutarate-dependent oxidoreductase. We obtained an X-ray crystal structure of TDO using SeMet-SAD phasing to 3.16 Å resolution. The structure reveals that TDO possesses a fold like that of Arabidopsis thaliana 2-oxoglutarate­iron-dependent oxygenase anthocyanidin synthase (ANS). Unlike ANS, this TDO structure lacks bound metals or cofactors, and we propose this is because the disordered flexible loop over the active site is sterically constrained from folding properly in the crystal lattice. A combination of mass spectrometry, nuclear magnetic resonance, and enzyme activity studies indicate that rice TDO oxidizes mesotrione in a series of steps; first producing 5-hydroxy-mesotrione and then oxy-mesotrione. Evidence suggests that 5-hydroxy-mesotrione is a much weaker inhibitor of HPPD than mesotrione, and oxy-mesotrione has virtually no inhibitory activity. Of the close homologues which have been tested, only corn and rice TDO have enzymatic activity and the ability to protect plants from mesotrione. Correlating sequence and structure has identified four amino acids necessary for TDO activity. Introducing these four amino acids imparts activity to a mesotrione-inactive TDO-like protein from sorghum, which may expand triketone herbicide resistance in new crop species.


Assuntos
4-Hidroxifenilpiruvato Dioxigenase , Arabidopsis , Dioxigenases , Oryza , Oryza/genética , Oryza/metabolismo , 4-Hidroxifenilpiruvato Dioxigenase/química , 4-Hidroxifenilpiruvato Dioxigenase/metabolismo , Ácidos Cetoglutáricos , Arabidopsis/metabolismo , Aminoácidos , Ferro
8.
Vaccine ; 39(8): 1349-1357, 2021 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-33518467

RESUMO

BACKGROUND: In Ontario, Canada, little is currently known about the extent to which un-immunized children may cluster geographically. Our objectives were to: describe the geographic distribution of fully un-immunized children; identify geographic clusters (hotspots) of un-immunized children; and to characterize the contribution of spatial effects and covariates on hotspots, where found. METHODS: Our analytic cohort consisted of Ontario students aged 7-17 years in the 2016-2017 school year. We defined students as un-immunized if they had zero doses of any vaccine and a non-medical exemption recorded in Ontario's registry. We calculated unadjusted proportions of un-immunized students by Census Subdivision (CSD) and then used a sequential approach to identify hotspots starting first with hotspot identification at the CSD level and then probed identified hotspots further by Dissemination Area (DA) and including covariates. Hotspots were identified using the Besag-York-Mollie Bayesian spatial model and were defined as areas with >95% probability of having two times the proportion of un-immunized students, relative to the province overall. RESULTS: We identified 15,208 (0.94%) un-immunized children within our cohort consisting of more than 1.61 million students. Unadjusted proportions of un-immunized students varied greatly by geography, ranging from 0% to 21.5% by CSD. We identified 16 hotspot CSDs which clustered in five distinct areas, all of which were located in southern Ontario. The contribution of covariates and spatial effects on the risk of having un-immunized students varied greatly across hotspot areas. CONCLUSIONS: Although the provincial proportion (0.94%) of un-immunized students is small, geographical clustering of such students is evident in Ontario and in some areas presents an important risk for future outbreaks. Further qualitative work within these hotspot areas would be a helpful next step to better characterize the factors associated with vaccine refusal in these communities.


Assuntos
Instituições Acadêmicas , Adolescente , Teorema de Bayes , Criança , Análise por Conglomerados , Humanos , Ontário/epidemiologia , Análise Espacial
9.
PLoS One ; 16(12): e0260532, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34928980

RESUMO

The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is a major maize pest in the United States causing significant economic loss. The emergence of field-evolved resistant WCR to Bacillus thuringiensis (Bt) traits has prompted the need to discover and deploy new insecticidal proteins in transgenic maize. In the current study we determined the crystal structure and mode of action (MOA) of the Vpb4Da2 protein (formerly known as Vip4Da2) from Bt, the first identified insecticidal Vpb4 protein with commercial level control against WCR. The Vpb4Da2 structure exhibits a six-domain architecture mainly comprised of antiparallel ß-sheets organized into ß-sandwich layers. The amino-terminal domains 1-3 of the protein share structural homology with the protective antigen (PA) PA14 domain and encompass a long ß-pore forming loop as in the clostridial binary-toxB module. Domains 5 and 6 at the carboxyl-terminal half of Vpb4Da2 are unique as this extension is not observed in PA or any other structurally-related protein other than Vpb4 homologs. These unique Vpb4 domains adopt the topologies of carbohydrate-binding modules known to participate in receptor-recognition. Functional assessment of Vpb4Da2 suggests that domains 4-6 comprise the WCR receptor binding region and are key in conferring the observed insecticidal activity against WCR. The current structural analysis was complemented by in vitro and in vivo characterizations, including immuno-histochemistry, demonstrating that Vpb4Da2 follows a MOA that is consistent with well-characterized 3-domain Bt insecticidal proteins despite significant structural differences.


Assuntos
Bacillus thuringiensis/metabolismo , Proteínas de Bactérias/química , Inseticidas/farmacologia , Sequência de Aminoácidos , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Besouros/efeitos dos fármacos , Besouros/crescimento & desenvolvimento , Cristalografia por Raios X , Inseticidas/química , Intestinos/metabolismo , Larva/efeitos dos fármacos , Larva/metabolismo , Mutagênese Sítio-Dirigida , Multimerização Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/farmacologia , Zea mays/metabolismo , Zea mays/parasitologia
10.
Proteins ; 78(2): 271-85, 2010 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-19731375

RESUMO

This study presents the results of a de novo approach modeling possible conformational dynamics of the extracellular (EC) loops in G-protein-coupled receptors (GPCRs), specifically in bovine rhodopsin (bRh), squid rhodopsin (sRh), human beta-2 adrenergic receptor (beta2AR), turkey beta-1 adrenergic receptor (beta1AR), and human A2 adenosine receptor (A2AR). The approach deliberately sacrificed a detailed description of any particular 3D structure of the loops in GPCRs in favor of a less precise description of many possible structures. Despite this, the approach found ensembles of the low-energy conformers of the EC loops that contained structures close to the available X-ray snapshots. For the smaller EC1 and EC3 loops (6-11 residues), our results were comparable with the best recent results obtained by other authors using much more sophisticated techniques. For the larger EC2 loops (25-34 residues), our results consistently yielded structures significantly closer to the X-ray snapshots than the results of the other authors for loops of similar size. The results suggested possible large-scale movements of the EC loops in GPCRs that might determine their conformational dynamics. The approach was also validated by accurately reproducing the docking poses for low-molecular-weight ligands in beta2AR, beta1AR, and A2AR, demonstrating the possible influence of the conformations of the EC loops on the binding sites of ligands. The approach correctly predicted the system of disulfide bridges between the EC loops in A2AR and elucidated the probable pathways for forming this system.


Assuntos
Receptores A2 de Adenosina/química , Receptores Adrenérgicos beta 1/química , Receptores Adrenérgicos beta 2/química , Rodopsina/química , Sequência de Aminoácidos , Animais , Bovinos , Cristalografia por Raios X , Decapodiformes , Humanos , Ligantes , Modelos Moleculares , Dados de Sequência Molecular , Ressonância Magnética Nuclear Biomolecular , Ligação Proteica , Conformação Proteica , Receptores A2 de Adenosina/metabolismo , Receptores Adrenérgicos beta 1/metabolismo , Receptores Adrenérgicos beta 2/metabolismo , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/metabolismo , Rodopsina/metabolismo , Turquia
12.
Vaccine ; 37(23): 3123-3132, 2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-31029513

RESUMO

BACKGROUND: Our objectives were: (1) to quantify and describe un-immunized students in Ontario, Canada and assess the extent to which these students have exemptions; and (2) to quantify and describe students with non-medical exemptions (NMEs), including what proportion have up-to-date immunizations. METHODS: We examined Ontario students 7 to 17 years-of-age in the 2016-2017 school year using information within a centralized immunization repository. We identified and described students with different immunization/exemption classifications by age, sex, school type, geography and area-level material deprivation using descriptive and multivariable logistic regression analyses. Finally, we assessed the immunization status of students with NMEs, by antigen. RESULTS: We found that students could be recorded as un-immunized with or without an NME, or be immunized with an NME. From a cohort of 1.65 million students, 2.9% of students had zero vaccine doses recorded, and of these 68% had no exemption of any kind. A total of 2.4% of students had an NME. Of these, 39% were un-immunized and 61% had received ≥1 vaccine. Among all students with NMEs, 19-48% had up-to-date immunizations, varying by antigen. Factors associated with increased odds of having a NME and being un-immunized included: attendance at private and 'other' schools, rural residence, and geography. Older age and greater area-level deprivation were associated with a reduced odds. CONCLUSIONS: Our assessment revealed that Ontario students with NMEs cannot be assumed to be un-immunized and at risk for all vaccine-preventable diseases. Conversely, not all un-immunized students had NMEs suggesting that future studies of un-immunized children in Ontario must consider additional factors beyond NME status alone. Other jurisdictions that use NME data to inform research and surveillance of vaccine hesitancy and risks for VPD outbreaks may wish to undertake a similar assessment to determine how well student NMEs correlate with student immunization status.


Assuntos
Imunização/legislação & jurisprudência , Imunização/estatística & dados numéricos , Instituições Acadêmicas/legislação & jurisprudência , Estudantes/estatística & dados numéricos , Vacinas/administração & dosagem , Adolescente , Criança , Surtos de Doenças/prevenção & controle , Feminino , Política de Saúde , Humanos , Masculino , Ontário , Aceitação pelo Paciente de Cuidados de Saúde , População , Recusa de Vacinação/legislação & jurisprudência
13.
Am J Orthopsychiatry ; 78(1): 1-10, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18444721

RESUMO

This study examines risks, resources, and adjustment among siblings of children with severe emotional disturbances (SED) involved in an initiative to develop family centered Systems of Care in North Carolina. These siblings experience many of the same risks as the children who have been diagnosed with SED (i.e., "targets"), but have received relatively little attention from the system or researchers. This first systematic study of these siblings describes an early sample (n = 56), compares them to their system-identified brothers and sisters, and explores contextual factors related to sibling resources and adjustment. Findings suggest the siblings, much like the targets: (a) have been exposed to extremely high levels of adversity, and (b) evidence substantial variability in behavioral and emotional strengths and social-emotional adjustment. Although many siblings exhibit significant strengths and positive adjustment, a substantial proportion displays levels of competencies or problem behaviors on par with those targeted to receive services. Factors associated with positive sibling adjustment are consistent with those identified in prior risk and resilience work. Additional systematic study of these children could have implications for service delivery and preventive interventions.


Assuntos
Adaptação Psicológica , Serviços de Saúde Mental/estatística & dados numéricos , Transtornos do Humor/psicologia , Irmãos , Adolescente , Cuidadores/psicologia , Criança , Pré-Escolar , Efeitos Psicossociais da Doença , Família , Feminino , Humanos , Masculino , Transtornos do Humor/diagnóstico , Transtornos do Humor/epidemiologia , North Carolina/epidemiologia , Relações Pais-Filho , Assistência ao Paciente/métodos , Relações Profissional-Família , Fatores de Risco , Relações entre Irmãos , Ajustamento Social , Inquéritos e Questionários
14.
Psychol Rep ; 103(2): 358-60, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19102458

RESUMO

The coverage of religion and mythology in undergraduate courses in the Psychology of Women was explored by (a) surveying a sample of undergraduate instructors (N=72); and (b) examining coverage in textbooks on the Psychology of Women (N=95). 48.6% of teachers said they include some coverage, while 43.1% said they never do. The total percentage of coverage in textbooks is small, ranging from a mean of 2.0% in the 1970s to 1.1% in the current decade.


Assuntos
Currículo/normas , Mitologia , Psicologia/educação , Religião , Estudantes , Adulto , Comportamento de Escolha , Feminino , Humanos , Preconceito , Livros de Texto como Assunto , Inconsciente Psicológico
15.
Structure ; 13(2): 225-34, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15698566

RESUMO

The study of short, autonomously folding peptides, or "miniproteins," is important for advancing our understanding of protein stability and folding specificity. Although many examples of synthetic alpha-helical structures are known, relatively few mixed alpha/beta structures have been successfully designed. Only one mixed-secondary structure oligomer, an alpha/beta homotetramer, has been reported thus far. In this report, we use structural analysis and computational design to convert this homotetramer into the smallest known alpha/beta-heterotetramer. Computational screening of many possible sequence/structure combinations led efficiently to the design of short, 21-residue peptides that fold cooperatively and autonomously into a specific complex in solution. A 1.95 A crystal structure reveals how steric complementarity and charge patterning encode heterospecificity. The first- and second-generation heterotetrameric miniproteins described here will be useful as simple models for the analysis of protein-protein interaction specificity and as structural platforms for the further elaboration of folding and function.


Assuntos
Biologia Computacional , Peptídeos/química , Sequência de Aminoácidos , Cristalização , Cristalografia por Raios X , Dados de Sequência Molecular , Mutação/genética , Peptídeos/genética , Dobramento de Proteína , Estrutura Secundária de Proteína
16.
Chem Biol Interact ; 240: 102-9, 2015 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-26296760

RESUMO

Fluorinated nucleoside analogues are a major class of cancer chemotherapy agents, and include the drugs 5-fluorouracil (5FU) and 5-fluoro-2'-deoxyuridine (FdUrd). The aim of this study was to examine the cellular toxicity of two novel fluorinated pyrimidine L-nucleosides that are enantiomers of D-nucleosides and may be able to increase selectivity for cancer cells as a result of their unnatural L-configuration. Two fluorinated pyrimidine L-nucleosides were examined in this study, L110 ([ß-L, ß-D]-5-fluoro-2'-deoxyuridine) and L117 (ß-L-deoxyuridine:ß-D-5'-fluoro-2'-deoxyuridine). The cytotoxicity of these L-nucleoside was determined in primary mouse fibroblasts and was compared with 5FU and FdUrd. In addition, the influence of p53 status on cytotoxicity was investigated. These cytotoxicity assays were performed on a matched set of primary mouse fibroblasts that were either wild type or null for the p53 tumour suppressor gene. It was found that cells lacking functional p53 were over 7500 times more sensitive to the drugs L110, L117 and FdUrd than cells containing wild type p53.


Assuntos
Antineoplásicos/toxicidade , Nucleosídeos de Pirimidina/toxicidade , Proteína Supressora de Tumor p53/metabolismo , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Desoxiuridina/análogos & derivados , Desoxiuridina/farmacologia , Desoxiuridina/uso terapêutico , Fluoruracila/farmacologia , Fluoruracila/uso terapêutico , Fluoruracila/toxicidade , Concentração Inibidora 50 , Camundongos , Estrutura Molecular , Nucleosídeos de Pirimidina/farmacologia , Nucleosídeos de Pirimidina/uso terapêutico
17.
PLoS One ; 6(7): e21832, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21760913

RESUMO

A vast majority of the burden from neglected tropical diseases result from helminth infections (nematodes and platyhelminthes). Parasitic helminthes infect over 2 billion, exerting a high collective burden that rivals high-mortality conditions such as AIDS or malaria, and cause devastation to crops and livestock. The challenges to improve control of parasitic helminth infections are multi-fold and no single category of approaches will meet them all. New information such as helminth genomics, functional genomics and proteomics coupled with innovative bioinformatic approaches provide fundamental molecular information about these parasites, accelerating both basic research as well as development of effective diagnostics, vaccines and new drugs. To facilitate such studies we have developed an online resource, HelmCoP (Helminth Control and Prevention), built by integrating functional, structural and comparative genomic data from plant, animal and human helminthes, to enable researchers to develop strategies for drug, vaccine and pesticide prioritization, while also providing a useful comparative genomics platform. HelmCoP encompasses genomic data from several hosts, including model organisms, along with a comprehensive suite of structural and functional annotations, to assist in comparative analyses and to study host-parasite interactions. The HelmCoP interface, with a sophisticated query engine as a backbone, allows users to search for multi-factorial combinations of properties and serves readily accessible information that will assist in the identification of various genes of interest. HelmCoP is publicly available at: http://www.nematode.net/helmcop.html.


Assuntos
Anti-Helmínticos/farmacologia , Genômica , Helmintíase/prevenção & controle , Helmintos/efeitos dos fármacos , Helmintos/genética , Internet , Software , Sequência de Aminoácidos , Animais , Helmintíase/imunologia , Helmintíase/parasitologia , Humanos , Anotação de Sequência Molecular , Dados de Sequência Molecular , Especificidade da Espécie , Tetra-Hidrofolato Desidrogenase/química , Interface Usuário-Computador , Vacinas
18.
PLoS One ; 6(4): e18381, 2011 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-21556146

RESUMO

Finding new drug targets for pathogenic infections would be of great utility for humanity, as there is a large need to develop new drugs to fight infections due to the developing resistance and side effects of current treatments. Current drug targets for pathogen infections involve only a single protein. However, proteins rarely act in isolation, and the majority of biological processes occur via interactions with other proteins, so protein-protein interactions (PPIs) offer a realm of unexplored potential drug targets and are thought to be the next-generation of drug targets. Parasitic worms were chosen for this study because they have deleterious effects on human health, livestock, and plants, costing society billions of dollars annually and many sequenced genomes are available. In this study, we present a computational approach that utilizes whole genomes of 6 parasitic and 1 free-living worm species and 2 hosts. The species were placed in orthologous groups, then binned in species-specific orthologous groups. Proteins that are essential and conserved among species that span a phyla are of greatest value, as they provide foundations for developing broad-control strategies. Two PPI databases were used to find PPIs within the species specific bins. PPIs with unique helminth proteins and helminth proteins with unique features relative to the host, such as indels, were prioritized as drug targets. The PPIs were scored based on RNAi phenotype and homology to the PDB (Protein DataBank). EST data for the various life stages, GO annotation, and druggability were also taken into consideration. Several PPIs emerged from this study as potential drug targets. A few interactions were supported by co-localization of expression in M. incognita (plant parasite) and B. malayi (H. sapiens parasite), which have extremely different modes of parasitism. As more genomes of pathogens are sequenced and PPI databases expanded, this methodology will become increasingly applicable.


Assuntos
Proteínas de Helminto/metabolismo , Helmintíase/prevenção & controle , Helmintos/patogenicidade , Sequência de Aminoácidos , Animais , Bases de Dados de Proteínas , Proteínas de Helminto/química , Humanos , Cadeias de Markov , Modelos Moleculares , Dados de Sequência Molecular , Ligação Proteica , Estrutura Secundária de Proteína , Homologia de Sequência de Aminoácidos , Especificidade da Espécie
19.
Nat Genet ; 43(3): 228-35, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21336279

RESUMO

Genome evolution studies for the phylum Nematoda have been limited by focusing on comparisons involving Caenorhabditis elegans. We report a draft genome sequence of Trichinella spiralis, a food-borne zoonotic parasite, which is the most common cause of human trichinellosis. This parasitic nematode is an extant member of a clade that diverged early in the evolution of the phylum, enabling identification of archetypical genes and molecular signatures exclusive to nematodes. We sequenced the 64-Mb nuclear genome, which is estimated to contain 15,808 protein-coding genes, at ∼35-fold coverage using whole-genome shotgun and hierarchal map-assisted sequencing. Comparative genome analyses support intrachromosomal rearrangements across the phylum, disproportionate numbers of protein family deaths over births in parasitic compared to a non-parasitic nematode and a preponderance of gene-loss and -gain events in nematodes relative to Drosophila melanogaster. This genome sequence and the identified pan-phylum characteristics will contribute to genome evolution studies of Nematoda as well as strategies to combat global parasites of humans, food animals and crops.


Assuntos
Genoma Helmíntico , Trichinella spiralis/genética , Animais , Sequência de Bases , Sequência Conservada , Evolução Molecular , Dados de Sequência Molecular , Nematoides/genética , Filogenia , Análise de Sequência de DNA/métodos
20.
Chem Biol Drug Des ; 75(3): 325-32, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20659113

RESUMO

G-protein coupled receptors play an essential role in many biological processes. Despite an increase in the number of solved X-ray crystal structures of G-protein coupled receptors, capturing a G-protein coupled receptor in its activated state for structural analysis has proven to be difficult. An unexplored paradigm is stabilization of one or more conformational states of a G-protein coupled receptor via binding a small molecule to the intracellular loops. A short tetrazole peptidomimetic based on the photoactivated state of rhodopsin-bound structure of Gt(alpha)(340-350) was previously designed and shown to stabilize the photoactivated state of rhodopsin, the G-protein coupled receptor involved in vision. A pharmacophore model derived from the designed tetrazole tetrapeptide was used for ligand-based virtual screening to enhance the possible discovery of novel scaffolds. Maybridge Hitfinder and National Cancer Institute diversity libraries were screened for compounds containing the pharmacophore. Forty-seven compounds resulted from virtually screening the Maybridge library, whereas no hits resulted with the National Cancer Institute library. Three of the 47 Maybridge compounds were found to stabilize the MII state. As these compounds did not inhibit binding of transducin to photoactivated state of rhodopsin, they were assumed to be allosteric ligands. These compounds are potentially useful for crystallographic studies where complexes with these compounds might capture rhodopsin in its activated conformational state.


Assuntos
Ligantes , Receptores Acoplados a Proteínas G/química , Regulação Alostérica , Azóis/química , Azóis/farmacologia , Ligação Proteica , Estabilidade Proteica , Receptores Acoplados a Proteínas G/metabolismo , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia
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