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1.
J Intellect Disabil Res ; 67(10): 986-1002, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37344986

RESUMO

BACKGROUND: No previous studies have reported predictors and moderators of outcome of psychological therapies for depression experienced by adults with intellectual disabilities (IDs). We investigated baseline variables as outcome predictors and moderators based on a randomised controlled trial where behavioural activation was compared with guided self-help. METHODS: This study was an exploratory secondary data analysis of data collected during a randomised clinical trial. Participants (n = 161) were randomised to behavioural activation or guided self-help and followed up for 12 months. Pre-treatment variables were included if they have previously been shown to be associated with an increased risk of having depression in adults with IDs or have been reported as a potential predictor or moderator of outcome of treatment for depression with psychological therapies. The primary outcome measure, the Glasgow Depression Scale for Adults with Learning Disabilities (GDS-LD), was used as the dependant variable in mixed effects regression analyses testing for predictors and moderators of outcome, with baseline GDS-LD, treatment group, study centre and antidepressant use as fixed effects, and therapist as a random effect. RESULTS: Higher baseline anxiety (mean difference in outcome associated with a 1 point increase in anxiety 0.164, 95% confidence interval [CI] 0.031, 0.297; P = 0.016), lower performance intelligence quotient (IQ) (mean difference in outcome associated with a 1 point increase in IQ 0.145, 95% CI 0.009, 0.280; P = 0.037) and hearing impairment (mean difference 3.449, 95% CI 0.466, 6.432; P = 0.024) were predictors of poorer outcomes, whilst greater severity of depressive symptoms at baseline (mean difference in outcome associated with 1 point increase in depression -0.160, 95% CI -0.806, -0.414; P < 0.001), higher expectation of change (mean difference in outcome associated with a 1 point increase in expectation of change -1.013, 95% CI -1.711, -0.314; p 0.005) and greater percentage of therapy sessions attended (mean difference in outcome with 1 point increase in percentage of sessions attended -0.058, 95% CI -0.099, -0.016; P = 0.007) were predictors of more positive outcomes for treatment after adjusting for randomised group allocation. The final model included severity of depressive and anxiety symptoms, lower WASI performance IQ subscale, hearing impairment, higher expectation of change and percentage of therapy sessions attended and explained 35.3% of the variance in the total GDS-LD score at 12 months (R2  = 0.353, F4, 128  = 17.24, P < 0.001). There is no evidence that baseline variables had a moderating effect on outcome for treatment with behavioural activation or guided self-help. CONCLUSIONS: Our results suggest that baseline variables may be useful predictors of outcomes of psychological therapies for adults with IDs. Further research is required to examine the value of these potential predictors. However, our findings suggest that therapists consider how baseline variables may enable them to tailor their therapeutic approach when using psychological therapies to treat depression experienced by adults with IDs.


Assuntos
Depressão , Deficiência Intelectual , Adulto , Humanos , Depressão/terapia , Deficiência Intelectual/terapia , Deficiência Intelectual/psicologia , Terapia Comportamental/métodos , Ansiedade , Comportamentos Relacionados com a Saúde
2.
Infect Genet Evol ; 68: 153-160, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30576837

RESUMO

The equine parasite Theilera equi continues to curtail global equine commerce due primarily to its ability to persist indefinitely in the immunocompetent horse. Details regarding the parasite life cycle, pathogenesis and mechanism of persistence remain unclear. The recently discovered T. haneyi is also capable of persistence in the horse, creating a potential reservoir for additional infections. These two divergent parasites share a unique gene family that expresses surface merozoite antigens, or equi merozoite antigens (EMAs). The EMA family was maintained in number and size in both parasites despite a species divergence of over 30 million years ago. This family is unique amongst Theilerias in number, structure and biochemical properties. In silico analysis revealed no evidence of selection for diversity within this family, indicating a role in host adaptation and persistence rather than antigenic variation and immune escape. Biochemical analysis revealed the presence of a conserved domain, homologous to the hemolysin toxin found in cobra venom. This finding combined with data from protein interaction prediction models may indicate interaction with the structural components of the host erythrocyte and a role in merozoite entry or escape. Additional predicted protein interactions focus on disruption of the enzymatic functions of the host cell, potentially resulting in enhanced parasite survival.


Assuntos
Antígenos de Protozoários/imunologia , Evolução Biológica , Doenças dos Cavalos/imunologia , Doenças dos Cavalos/parasitologia , Theileria/imunologia , Theileriose/imunologia , Theileriose/parasitologia , Sequência de Aminoácidos , Animais , Antígenos de Protozoários/química , Antígenos de Protozoários/genética , Biodiversidade , Códon , Sequência Conservada , Genoma de Protozoário , Cavalos , Interações Hospedeiro-Parasita/imunologia , Merozoítos/imunologia , Theileria/genética
3.
Ticks Tick Borne Dis ; 9(2): 135-140, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28887100

RESUMO

Certain countries including the United States remain non-endemic for particular infectious diseases such as equine piroplasmosis through import restrictions and surveillance. Endemic regions often employ premunition as the primary method to control disease, however in non-endemic countries, chemosterilization combined with methods to confirm parasite elimination are required to maintain disease-free status. The ability of imidocarb diproprionate (ID) to clear persistent Theileria equi infection from infected horses has been shown through the inability of treated horses to transmit via blood transfer. However, the common lengthy persistence of anti-T. equi antibody causes regulatory tests such as cELISA or IFA to remain positive for extended periods. Persistence of positive testing creates challenges for regulatory veterinary medicine and international trade. Concordance between nested polymerase chain reaction (nPCR) targeting the ema1 gene and immunoblotting (IB) measuring declination in anti-EMA1 and anti-EMA2 antibody were used to verify clearance of T. equi from 179 ID-treated horses. These data support the use of IB to demonstrate declining anti-EMA1 and EMA2 titers in T. equi-infected horses subsequent to successful ID treatment. Such data provide concordant support to a negative nPCR and allow for a more timely determination of effective ID clearance of T. equi. The post ID treatment results indicate that while nPCR was consistently negative by 14 days and cELISA generally remained positive after 1 year, immunoblot was on average negative after 4 months and 100% in agreement with nPCR.


Assuntos
Antiprotozoários/uso terapêutico , Western Blotting/veterinária , Doenças dos Cavalos/prevenção & controle , Imidocarbo/análogos & derivados , Reação em Cadeia da Polimerase/veterinária , Theileriose/prevenção & controle , Animais , Anticorpos Antiprotozoários/sangue , Western Blotting/métodos , Ensaio de Imunoadsorção Enzimática/veterinária , Doenças dos Cavalos/parasitologia , Cavalos , Imidocarbo/uso terapêutico , Reação em Cadeia da Polimerase/métodos , Proteínas de Protozoários/análise , Texas , Theileria/efeitos dos fármacos , Theileriose/parasitologia
4.
BMC Vet Res ; 13(1): 171, 2017 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-28606148

RESUMO

BACKGROUND: The objective of the current study was to develop a stochastic agent-based model using empirical data from Ontario (Canada) swine sites in order to evaluate different surveillance strategies for detection of emerging porcine reproductive and respiratory syndrome virus (PRRSV) strains at the regional level. Four strategies were evaluated, including (i) random sampling of fixed numbers of swine sites monthly; (ii) risk-based sampling of fixed numbers, specifically of breeding sites (high-consequence sites); (iii) risk-based sampling of fixed numbers of low biosecurity sites (high-risk); and (iv) risk-based sampling of breeding sites that are characterized as low biosecurity sites (high-risk/high-consequence). The model simulated transmission of a hypothetical emerging PRRSV strain between swine sites through three important industry networks (production system, truck and feed networks) while considering sites' underlying immunity due to past or recent exposure to heterologous PRRSV strains, as well as demographic, geographic and biosecurity-related PRRS risk factors. Outcomes of interest included surveillance system sensitivity and time to detection of the three first cases over a period of approximately three years. RESULTS: Surveillance system sensitivities were low and time to detection of three first cases was long across all examined scenarios. CONCLUSION: Traditional modes of implementing high-risk and high-consequence risk-based surveillance based on site's static characteristics do not appear to substantially improve surveillance system sensitivity. Novel strategies need to be developed and considered for rapid detection of this and other emerging swine infectious diseases. None of the four strategies compared herein appeared optimal for early detection of an emerging PPRSV strain at the regional level considering model assumptions, the underlying population of interest, and absence of other forms of surveillance.


Assuntos
Doenças Transmissíveis Emergentes/veterinária , Monitoramento Epidemiológico/veterinária , Modelos Biológicos , Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína , Animais , Canadá/epidemiologia , Doenças Transmissíveis Emergentes/virologia , Simulação por Computador , Síndrome Respiratória e Reprodutiva Suína/transmissão , Processos Estocásticos , Suínos
5.
Breast Cancer (Auckl) ; 10: 45-52, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27127408

RESUMO

BACKGROUND: Breast cancer is the most common form of cancer affecting women in the Bahamas, which consists of many islands. This is the first attempt to identify which island has the highest occurrence of breast cancer. OBJECTIVE: The aim of this study was to describe the sociodemographical and spatial features of breast cancer in the Bahamas in 2009-2011. METHODS: A review of the medical records of all women with a confirmed diagnosis of breast cancer during the period January 1, 2009-December 31, 2011, was undertaken. Data were first obtained from the National Oncology Board of the Bahamas and validated by a review of the medical records. The patient address was geocoded and mapped using ArcGIS 10.0 Environmental Systems Research Institute (ESRI) to satellite images obtained from The Nature Conservancy in the Bahamas. RESULTS: We recruited 270 patients who satisfied the entry criteria. The cumulative incidences of breast cancer for the years 2009-2011 were 51.4, 45.4, and 51.4, respectively. Breast cancer occurred most often in women of African origin with a mean age at diagnosis of 56.6 ± 13.8 years. Ductal carcinoma was the most common histological type observed with most cancers occurring in Grade II or higher and presenting as late stage (≥ Stage II). Surgery was the preferred method of treatment with modified radical mastectomy being the procedure of choice. Spatial distribution of cases across the Bahamas revealed one cluster, which is present on the island of New Providence. Further analysis of New Providence showed a consistently skewed kernel density in the central and eastern regions, compared with a scattered distribution in the southern and western regions. CONCLUSION: The island of New Providence had the highest occurrence of breast cancer among all the islands of the Bahamas. The increasing incidence of breast cancer in young women is likely to impose a significant burden on the future of Bahamian health care.

7.
Leukemia ; 30(3): 594-604, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26530011

RESUMO

PRDM1/Blimp1, a master regulator of B-cell terminal differentiation, has been identified as a tumor suppressor gene in aggressive lymphomas, including diffuse large B-cell lymphoma (DLBCL). It has been shown in DLBCL and Hodgkin lymphoma that PRDM1 is downregulated by cellular microRNAs. In this study, we identify the Epstein-Barr virus (EBV) microRNA (miRNA), EBV-miR-BHRF1-2, as a viral miRNA regulator of PRDM1. EBV-miR-BHRF1-2 repressed luciferase reporter activity by specific interaction with the seed region within the PRDM1 3' untranslated region. EBV-miR-BHRF1-2 inhibition upregulated PRDM1 protein expression in lymphoblastoid cell lines (LCL), supporting a role of miR-BHRF1-2 in PRDM1 downregulation in vivo. Discordance of PRDM1 messenger RNA and protein expressions is associated with high EBV-miR-BHRF1-2 levels in LCLs and primary post-transplant EBV-positive DLBCL. Enforced expression of PRDM1-induced apoptosis and cell cycle arrest in LCL cells. Inhibition of EBV-miR-BHRF1-2 negatively regulates cell cycle and decreases expression of SCARNA20, a small nucleolar RNA that is also downregulated by PRDM1 overexpression. The interaction between EBV-miR-BHRF1-2 and PRDM1 may be one of the mechanisms by which EBV-miR-BHRF1-2 promotes EBV lymphomagenesis. Our results support the potential of EBV-miR-BHRF1-2 as a therapeutic target in EBV-associated lymphoma.


Assuntos
Carcinogênese/genética , Infecções por Vírus Epstein-Barr/genética , Regulação Neoplásica da Expressão Gênica , Linfoma Difuso de Grandes Células B/genética , MicroRNAs/genética , Proteínas Repressoras/genética , Proteínas Virais/genética , Regiões 3' não Traduzidas , Sequência de Bases , Sítios de Ligação , Carcinogênese/metabolismo , Carcinogênese/patologia , Pontos de Checagem do Ciclo Celular , Linhagem Celular Tumoral , Infecções por Vírus Epstein-Barr/metabolismo , Infecções por Vírus Epstein-Barr/patologia , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/patogenicidade , Interações Hospedeiro-Patógeno , Humanos , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/patologia , MicroRNAs/metabolismo , Dados de Sequência Molecular , Inclusão em Parafina , Fator 1 de Ligação ao Domínio I Regulador Positivo , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , RNA Nucleolar Pequeno/genética , RNA Nucleolar Pequeno/metabolismo , Proteínas Repressoras/metabolismo , Transdução de Sinais , Fixação de Tecidos , Proteínas Virais/antagonistas & inibidores , Proteínas Virais/metabolismo
8.
Biochemistry ; 54(22): 3528-42, 2015 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-25962980

RESUMO

In this work, we obtain the data needed to predict chemical interactions of polyethylene glycols (PEGs) and glycerol with proteins and related organic compounds and thereby interpret or predict chemical effects of PEGs on protein processes. To accomplish this, we determine interactions of glycerol and tetraEG with >30 model compounds displaying the major C, N, and O functional groups of proteins. Analysis of these data yields coefficients (α values) that quantify interactions of glycerol, tetraEG, and PEG end (-CH2OH) and interior (-CH2OCH2-) groups with these groups, relative to interactions with water. TetraEG (strongly) and glycerol (weakly) interact favorably with aromatic C, amide N, and cationic N, but unfavorably with amide O, carboxylate O, and salt ions. Strongly unfavorable O and salt anion interactions help make both small and large PEGs effective protein precipitants. Interactions of tetraEG and PEG interior groups with aliphatic C are quite favorable, while interactions of glycerol and PEG end groups with aliphatic C are not. Hence, tetraEG and PEG300 favor unfolding of the DNA-binding domain of lac repressor (lacDBD), while glycerol and di- and monoethylene glycol are stabilizers. Favorable interactions with aromatic and aliphatic C explain why PEG400 greatly increases the solubility of aromatic hydrocarbons and steroids. PEG400-steroid interactions are unusually favorable, presumably because of simultaneous interactions of multiple PEG interior groups with the fused ring system of the steroid. Using α values reported here, chemical contributions to PEG m-values can be predicted or interpreted in terms of changes in water-accessible surface area (ΔASA) and separated from excluded volume effects.


Assuntos
Proteínas de Escherichia coli/química , Glicerol/química , Repressores Lac/química , Modelos Químicos , Polietilenoglicóis/química
9.
Biopolymers ; 103(9): 517-27, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25924886

RESUMO

Small and large PEGs greatly increase chemical potentials of globular proteins (µ2), thereby favoring precipitation, crystallization, and protein-protein interactions that reduce water-accessible protein surface and/or protein-PEG excluded volume. To determine individual contributions of PEG-protein chemical and excluded volume interactions to µ2 as functions of PEG molality m3 , we analyze published chemical potential increments µ23 = dµ2/dm3 quantifying unfavorable interactions of PEG (PEG200-PEG6000) with BSA and lysozyme. For both proteins, µ23 increases approximately linearly with the number of PEG residues (N3). A 1 molal increase in concentration of PEG -CH2 OCH2 - groups, for any chain-length PEG, increases µBSA by ∼2.7 kcal/mol and µlysozyme by ∼1.0 kcal/mol. These values are similar to predicted chemical interactions of PEG -CH2 OCH2 - groups with these protein components (BSA ∼3.3 kcal/mol, lysozyme ∼0.7 kcal/mol), dominated by unfavorable interactions with amide and carboxylate oxygens and counterions. While these chemical effects should be dominant for small PEGs, larger PEGS are expected to exhibit unfavorable excluded volume interactions and reduced chemical interactions because of shielding of PEG residues in PEG flexible coils. We deduce that these excluded volume and chemical shielding contributions largely compensate, explaining why the dependence of µ23 on N3 is similar for both small and large PEGs.


Assuntos
Polietilenoglicóis/química , Polietilenoglicóis/metabolismo , Proteínas/química , Proteínas/metabolismo , Animais , Bovinos , DNA , Muramidase/química , Muramidase/metabolismo , Ligação Proteica , Soroalbumina Bovina/química , Soroalbumina Bovina/metabolismo , Termodinâmica
10.
Contemp Clin Trials ; 41: 100-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25602581

RESUMO

BACKGROUND: Relapse prevention interventions for Bipolar Disorder are effective but implementation in routine clinical services is poor. Web-based approaches offer a way to offer easily accessible access to evidence based interventions at low cost, and have been shown to be effective for other mood disorders. METHODS/DESIGN: This protocol describes the development and feasibility testing of the ERPonline web-based intervention using a single blind randomised controlled trial. Data will include the extent to which the site was used, detailed feedback from users about their experiences of the site, reported benefits and costs to mental health and wellbeing of users, and costs and savings to health services. We will gain an estimate of the likely effect size of ERPonline on a range of important outcomes including mood, functioning, quality of life and recovery. We will explore potential mechanisms of change, giving us a greater understanding of the underlying processes of change, and consequently how the site could be made more effective. We will be able to determine rates of recruitment and retention, and identify what factors could improve these rates. DISCUSSION: The findings will be used to improve the site in accordance with user needs, and inform the design of a large scale evaluation of the clinical and cost effectiveness of ERPonline. They will further contribute to the growing evidence base for web-based interventions designed to support people with mental health problems.


Assuntos
Transtorno Bipolar/terapia , Internet , Aceitação pelo Paciente de Cuidados de Saúde , Prevenção Secundária , Autocuidado/métodos , Terapia Assistida por Computador/métodos , Adaptação Psicológica , Adulto , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pesquisa Qualitativa , Qualidade de Vida , Método Simples-Cego , Resultado do Tratamento
11.
Blood Cancer J ; 4: e261, 2014 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-25382611

RESUMO

PRDM1/Blimp-1 is a tumor suppressor gene in the activated B-cell subtype of diffuse large B-cell lymphomas. Its inactivation contributes to pathogenesis in this setting by impairing terminal B-cell differentiation induced by constitutive nuclear factor-κB activation. The role of PRDM1 in Burkitt lymphoma (BL) lymphomagenesis is not known. Here we identified hypermethylation of the promoter region and exon 1 of PRDM1 in all six Epstein-Barr virus (EBV)-positive BL cell lines and 12 of 23 (52%) primary EBV-positive BL or BL-related cases examined, but in none of the EBV-negative BL cell lines or primary tumors that we assessed, implying a tumor suppressor role for PRDM1 specifically in EBV-associated BL. A direct induction of PRDM1 hypermethylation by EBV is unlikely, as PRDM1 hypermethylation was not observed in EBV-immortalized B lymphoblastoid cell lines. Treatment of EBV-positive BL cells with 5' azacytidine resulted in PRDM1 induction associated with PRDM1 demethylation, consistent with transcriptional silencing of PRDM1 as a result of DNA methylation. Overexpression of PRDM1 in EBV-positive BL cell lines resulted in cell cycle arrest. Our results expand the spectrum of lymphoid malignancies in which PRDM1 may have a tumor suppressor role and identify an epigenetic event that likely contributes to the pathogenesis of BL.


Assuntos
Linfoma de Burkitt/metabolismo , Metilação de DNA , Herpesvirus Humano 4 , Proteínas Repressoras/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Linfoma de Burkitt/genética , Linfoma de Burkitt/patologia , Linfoma de Burkitt/virologia , Linhagem Celular Tumoral , Feminino , Humanos , Masculino , Fator 1 de Ligação ao Domínio I Regulador Positivo , Proteínas Repressoras/genética , Proteínas Supressoras de Tumor/genética
14.
Anim Genet ; 45(2): 297-300, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24303974

RESUMO

Ovine lentivirus (OvLV) is a macrophage-tropic lentivirus found in many countries that causes interstitial pneumonia, mastitis, arthritis and cachexia in sheep. There is no preventive vaccine and no cure, but breed differences suggest marker-assisted selective breeding might improve odds of infection and control of OvLV post-infection. Although variants in TMEM154 have consistent association with odds of infection, no variant in any gene has been associated with host control of OvLV post-infection in multiple animal sets. Proviral concentration is a live-animal diagnostic measure of OvLV control post-infection related to severity of OvLV-induced lesions. A recent genome-wide association study identified a region including four zinc finger genes associated with proviral concentration in one Rambouillet flock. To refine this region, we tested additional variants and identified a small insertion/deletion variant near ZNF389 that showed consistent association with proviral concentration in three animal sets (P < 0.05). These animal sets contained Rambouillet, Polypay and crossbred sheep from multiple locations and management conditions. Strikingly, one flock had exceptionally high prevalence (>87%, including yearlings) and mean proviral concentration (>950 copies/µg), possibly due to needle sharing. The best estimate of proviral concentration by genotype, obtained from all 1310 OvLV-positive animals tested, showed insertion homozygotes had less than half the proviral concentration of other genotypes (P < 0.0001). Future work will test additional breeds, management conditions and viral subtypes, and identify functional properties of the haplotype this deletion variant tracks. To our knowledge, this is the first genetic variant consistently associated with host control of OvLV post-infection in multiple sheep flocks.


Assuntos
Resistência à Doença/genética , Infecções por Lentivirus/veterinária , Deleção de Sequência , Doenças dos Ovinos/genética , Animais , Genótipo , Infecções por Lentivirus/genética , Infecções por Lentivirus/imunologia , Lentivirus Ovinos-Caprinos/imunologia , Ovinos , Doenças dos Ovinos/imunologia
15.
J Vet Intern Med ; 27(6): 1334-46, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24033559

RESUMO

Equine piroplasmosis is caused by one of 2 erythrocytic parasites Babesia caballi or Theileria equi. Although the genus of the latter remains controversial, the most recent designation, Theileria, is utilized in this review. Shared pathogenesis includes tick-borne transmission and erythrolysis leading to anemia as the primary clinical outcome. Although both parasites are able to persist indefinitely in their equid hosts, thus far, only B. caballi transmits across tick generations. Pathogenesis further diverges after transmission to equids in that B. caballi immediately infects erythrocytes, whereas T.equi infects peripheral blood mononuclear cells. The recent re-emergence of T.equi in the United States has increased awareness of these tick-borne pathogens, especially in terms of diagnosis and control. This review focuses in part on factors leading to the re-emergence of infection and disease of these globally important pathogens.


Assuntos
Babesia/crescimento & desenvolvimento , Babesiose/veterinária , Doenças dos Cavalos/parasitologia , Theileria/crescimento & desenvolvimento , Theileriose/parasitologia , Carrapatos/parasitologia , Animais , Babesiose/sangue , Babesiose/epidemiologia , Babesiose/parasitologia , Babesiose/transmissão , Doenças dos Cavalos/sangue , Doenças dos Cavalos/epidemiologia , Doenças dos Cavalos/transmissão , Cavalos , Prevalência , Theileriose/sangue , Theileriose/epidemiologia , Theileriose/transmissão , Estados Unidos/epidemiologia
16.
Proc Natl Acad Sci U S A ; 108(31): 12699-704, 2011 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-21742980

RESUMO

Small solutes affect protein and nucleic acid processes because of favorable or unfavorable chemical interactions of the solute with the biopolymer surface exposed or buried in the process. Large solutes also exclude volume and affect processes where biopolymer molecularity and/or shape changes. Here, we develop an analysis to separate and interpret or predict excluded volume and chemical effects of a flexible coil polymer on a process. We report a study of the concentration-dependent effects of the full series from monomeric to polymeric PEG on intramolecular hairpin and intermolecular duplex formation by 12-nucleotide DNA strands. We find that chemical effects of PEG on these processes increase in proportion to the product of the amount of DNA surface exposed on melting and the amount of PEG surface that is accessible to this DNA, and these effects are completely described by two interaction terms that quantify the interactions between this DNA surface and PEG end and interior groups. We find that excluded volume effects, once separated from these chemical effects, are quantitatively described by the analytical theory of Hermans, which predicts the excluded volume between a flexible polymer and a rigid molecule. From this analysis, we show that at constant concentration of PEG monomer, increasing PEG size increases the excluded volume effect but decreases the chemical interaction effect, because in a large PEG coil a smaller fraction of the monomers are accessible to the DNA. Volume exclusion by PEG has a much larger effect on intermolecular duplex formation than on intramolecular hairpin formation.


Assuntos
Algoritmos , DNA/química , Modelos Químicos , Conformação de Ácido Nucleico , Sequência de Bases , Relação Dose-Resposta a Droga , Etilenoglicol/química , Etilenoglicol/farmacologia , Etilenoglicóis/química , Etilenoglicóis/farmacologia , Cinética , Desnaturação de Ácido Nucleico/efeitos dos fármacos , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Polímeros/química , Polímeros/farmacologia , Cloreto de Potássio/química , Cloreto de Potássio/farmacologia , Propriedades de Superfície , Termodinâmica , Água/química
17.
J Anal Toxicol ; 35(4): 199-204, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21513612

RESUMO

Imidocarb [N,N'-bis[3-(4,5-dihydro-1H-imidazol-2-yl)phenyl]urea, C(19)H(20)N(6)O(1), m.w. 348.41] is a symmetrical carbanilide derivative used to treat disease caused by protozoans of the Babesia genus. Imidocarb, however, is also considered capable of suppressing Babesia-specific immune responses, allowing Babesia-positive horses to pass a complement fixation test (CFT) without eliminating the infection. This scenario could enable Babesia-infected horses to pass CFT-based importation tests. It is imperative to unequivocally identify and quantify equine tissue residues of imidocarb by mass spectrometry to address this issue. As a pretext to development of sensitive tissue assays, we have investigated possibilities of mass spectrometric (MS) detection of imidocarb. Our analyses disclosed that an unequivocal mass spectral analysis of imidocarb is challenging because of its rapid fragmentation under standard gas chromatography (GC)-MS conditions. In contrast, solution chemistry of imidocarb is more stable but involves distribution into mono- and dicationic species, m/z 349 and 175, respectively, in acid owing to the compound's inherent symmetrical nature. Dicationic imidocarb was the preferred complex as viewed by either direct infusion-electrospray-MS or by liquid chromatography (LC)-MS. Dicationic imidocarb multiple reaction monitoring (MRM: m/z 175 → 162, 145, and 188) therefore offer the greatest opportunities for sensitive detection and LC-MS is more likely than GC-MS to yield a useful quantitative forensic analytical method for detecting imidocarb in horses.


Assuntos
Antiprotozoários/química , Imidocarbo/química , Espectrometria de Massas/métodos , Antiprotozoários/análise , Cromatografia Líquida , Cromatografia Gasosa-Espectrometria de Massas , Imidocarbo/análise
18.
Mod Pathol ; 24(1): 108-16, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20852592

RESUMO

Splenic hamartoma is a rare tumor-like lesion composed of structurally disorganized red pulp elements. It has been hypothesized that two other splenic lesions, cord capillary hemangioma and myoid angioendothelioma, may fall within the spectrum of splenic hamartoma, simply representing morphological variants. In this study, we compared the vascular and stromal composition of cord capillary hemangioma and myoid angioendothelioma with those of classical hamartoma. In addition, we assessed the clonal vs polyclonal nature of the lesions in nine female cases by performing clonality analysis for X-chromosome inactivation at the human androgen receptor locus (HUMARA) on laser-assisted microdissected samples. In 15 of 17 cases, increased reticulin and/or collagen content was observed. The classical hamartoma cases showed a vasculature predominantly composed of CD8+ CD31+ CD34- splenic sinuses, whereas cases of cord capillary hemangioma and myoid angioendothelioma contained many CD8- CD31+ CD34+ cord capillaries, but very little CD8+ vasculature. All cases lacked expression of D2-40 and Epstein Barr virus-encoded RNA. All cases showed a proliferation index of ≤5% by Ki-67. Cases of classical hamartoma lacked significant perisinusoidal expression of collagen IV and low-affinity nerve growth factor receptor. Both markers were variably expressed in the other lesions. Increased CD163-positive histiocytes were found in four cases (three cord capillary hemangiomas and one myoid angioendothelioma). HUMARA analysis was informative in all nine tested cases, of which three cases showed a non-random X-chromosome inactivation pattern, indicating clonality. All three clonal cases were cord capillary hemangiomas. Our study has shown that in spite of considerable morphologic heterogeneity and overlapping features, classical hamartoma and cord capillary hemangioma and myoid angioendothelioma are different in terms of their vascular and stromal composition. Clonality analysis supports a true neoplastic origin for the cord capillary hemangioma. A larger study using additional immunohistochemical and molecular studies is necessary to further evaluate the biological significance of the current findings.


Assuntos
Cromossomos Humanos X , Hamartoma/genética , Hemangioma Capilar/genética , Neoplasias Esplênicas/genética , Inativação do Cromossomo X/genética , Adolescente , Adulto , Idoso , Criança , Células Clonais , Diagnóstico Diferencial , Feminino , Hamartoma/patologia , Hemangioendotelioma/genética , Hemangioendotelioma/patologia , Hemangioma Capilar/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Esplênicas/patologia , Adulto Jovem
19.
Parasite Immunol ; 33(1): 34-44, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21155841

RESUMO

The spleen is a critical organ in defence against haemoparasitic diseases like babesiosis. Many in vitro and ex vivo studies have identified splenic cells working in concert to activate mechanisms required for successful resolution of infection. The techniques used in those studies, however, remove cells from the anatomical context in which cell interaction and trafficking take place. In this study, an immunohistological approach was used to monitor the splenic distribution of defined cells during the acute response of naïve calves to Babesia bovis infection. Splenomegaly was characterized by disproportionate hyperplasia of large versus small leucocytes and altered distribution of several cell types thought to be important in mounting an effective immune response. In particular, the results suggest that the initial crosstalk between NK cells and immature dendritic cells occurs within the marginal zone and that immature dendritic cells are first redirected to encounter pathogens as they enter the spleen and then mature as they process antigen and migrate to T-cell-rich areas. The results of this study are remarkably similar to those observed in a mouse model of malarial infection, suggesting these dynamic events may be central to the acute response of naïve animals to haemoparasitic infection.


Assuntos
Babesia bovis/imunologia , Babesia bovis/parasitologia , Babesiose/imunologia , Babesiose/parasitologia , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/parasitologia , Células Dendríticas/imunologia , Células Dendríticas/parasitologia , Imunofenotipagem , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/parasitologia , Baço/imunologia , Baço/parasitologia , Esplenomegalia/imunologia , Esplenomegalia/parasitologia , Doença Aguda , Animais , Antígenos de Protozoários/imunologia , Babesia bovis/ultraestrutura , Babesiose/veterinária , Bovinos , Doenças dos Bovinos/fisiopatologia , Contagem de Células , Proliferação de Células , Imuno-Histoquímica , Imunofenotipagem/veterinária , Espectroscopia de Ressonância Magnética , Masculino , Tamanho do Órgão , Baço/fisiopatologia , Esplenomegalia/veterinária
20.
Vet Pathol ; 47(3): 518-28, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20382821

RESUMO

In situ detection of ovine progressive pneumonia virus (OPPV) and the phenotypic identification of the cells that harbor OPPV have not been described for the OPPV-affected tissues, which include lung, mammary gland, synovial membranes of the carpal joint, and choroid plexus of the brain. In this study, the authors first developed a single enzyme-based automated immunohistochemical (IHC) analysis for detection of OPPV capsid antigen (CA) on OPPV-affected tissues, using 2 anti-CAEV CA monoclonal antibodies, 5A1 and 10A1, and 2 enzyme-based IHC systems. Out of 10 naturally and persistently OPPV-infected ewes, OPPV CA was detected in intercellular regions of the carpal synovial membrane of 1 ewe, in cells resembling alveolar macrophages and pulmonary interstitial macrophages in lung tissue of 3 ewes, and in mammary alveolar cells of 1 ewe. Furthermore, dual enzyme-based automated IHC analyses revealed that OPPV CA was predominantly detected in CD172a- or CD163-positive alveolar macrophages of the lungs and mammary gland. That anti-inflammatory (CD163) and downregulatory (CD172a) types of alveolar macrophage harbor OPPV CA leads to the possibility that during persistent infection with OPPV, the host alveolar macrophage might serve to limit inflammation while OPPV persists undetected by the host adaptive immune response in the lung and mammary gland.


Assuntos
Antígenos Virais/análise , Infecções por Lentivirus/veterinária , Lentivirus Ovinos-Caprinos/imunologia , Macrófagos Alveolares/virologia , Doenças dos Ovinos/virologia , Animais , Antígenos CD/análise , Antígenos de Diferenciação Mielomonocítica/análise , Capsídeo/imunologia , Plexo Corióideo/virologia , Feminino , Infecções por Lentivirus/imunologia , Infecções por Lentivirus/virologia , Macrófagos Alveolares/imunologia , Glândulas Mamárias Animais/virologia , Receptores de Superfície Celular/análise , Ovinos , Doenças dos Ovinos/imunologia , Membrana Sinovial/virologia
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