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1.
J Steroid Biochem Mol Biol ; 243: 106571, 2024 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-38909866

RESUMO

Prostate cancer is primarily hormone-dependent, and medical treatments have focused on inhibiting androgen biosynthesis or signaling through various approaches. Despite significant advances with the introduction of androgen receptor signalling inhibitors (ARSIs), patients continue to progress to castration-resistant prostate cancer (CRPC), highlighting the need for targeted therapies that extend beyond hormonal blockade. Chimeric Antigen Receptor (CAR) T cells and other engineered immune cells represent a new generation of adoptive cellular therapies. While these therapies have significantly enhanced outcomes for patients with hematological malignancies, ongoing research is exploring the broader use of CAR T therapy in solid tumors, including advanced prostate cancer. In general, CAR T cell therapies are less effective against solid cancers with the immunosuppressive tumor microenvironment hindering T cell infiltration, activation and cytotoxicity following antigen recognition. In addition, inherent tumor heterogeneity exists in patients with advanced prostate cancer that may prevent durable therapeutic responses using single-target agents. These barriers must be overcome to inform clinical trial design and improve treatment efficacy. In this review, we discuss the innovative and rationally designed strategies under investigation to improve the clinical translation of cellular immunotherapy in prostate cancer and maximise therapeutic outcomes for these patients.

2.
J Hosp Infect ; 147: 25-31, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38447803

RESUMO

Healthcare hygiene plays a crucial role in the prevention of healthcare-associated infections. Patients admitted to a room where the previous occupant had a multi-drug-resistant bacterial infection are at an increased risk of colonization and infection with the same organism. A 2006 systematic review by Kramer et al. found that certain pathogens can survive for months on dry surfaces. The aim of this review is to update Kramer et al.'s previous review and provide contemporary data on the survival of pathogens relevant to the healthcare environment. We systematically searched Ovid MEDLINE, CINAHL and Scopus databases for studies that described the survival time of common nosocomial pathogens in the environment. Pathogens included in the review were bacterial, viral, and fungal. Studies were independently screened against predetermined inclusion/exclusion criteria by two researchers. Conflicts were resolved by one of two senior researchers. A spreadsheet was developed for the data extraction. The search identified 1736 studies. Following removal of duplicates and application of the search criteria, the synthesis of results from 62 included studies were included. 117 organisms were reported. The longest surviving organism reported was Klebsiella pneumoniae which was found to have persisted for 600 days. Common pathogens of concern to infection prevention and control, can survive or persist on inanimate surfaces for months. This data supports the need for a risk-based approach to cleaning and disinfection practices, accompanied by appropriate training, audit and feedback which are proven to be effective when adopted in a 'bundle' approach.


Assuntos
Bactérias , Infecção Hospitalar , Fungos , Humanos , Infecção Hospitalar/prevenção & controle , Infecção Hospitalar/microbiologia , Bactérias/classificação , Bactérias/isolamento & purificação , Fungos/isolamento & purificação , Fungos/classificação , Microbiologia Ambiental , Fatores de Tempo , Vírus/classificação , Vírus/isolamento & purificação , Vírus/patogenicidade
3.
Nat Commun ; 14(1): 5346, 2023 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-37660083

RESUMO

Chimeric antigen receptor (CAR) T cells have transformed the treatment landscape for hematological malignancies. However, CAR T cells are less efficient against solid tumors, largely due to poor infiltration resulting from the immunosuppressive nature of the tumor microenvironment (TME). Here, we assessed the efficacy of Lewis Y antigen (LeY)-specific CAR T cells in patient-derived xenograft (PDX) models of prostate cancer. In vitro, LeY CAR T cells directly killed organoids derived from androgen receptor (AR)-positive or AR-null PDXs. In vivo, although LeY CAR T cells alone did not reduce tumor growth, a single prior dose of carboplatin reduced tumor burden. Carboplatin had a pro-inflammatory effect on the TME that facilitated early and durable CAR T cell infiltration, including an altered cancer-associated fibroblast phenotype, enhanced extracellular matrix degradation and re-oriented M1 macrophage differentiation. In a PDX less sensitive to carboplatin, CAR T cell infiltration was dampened; however, a reduction in tumor burden was still observed with increased T cell activation. These findings indicate that carboplatin improves the efficacy of CAR T cell treatment, with the extent of the response dependent on changes induced within the TME.


Assuntos
Fibroblastos Associados a Câncer , Neoplasias da Próstata , Masculino , Animais , Humanos , Carboplatina/farmacologia , Carboplatina/uso terapêutico , Microambiente Tumoral , Linfócitos T , Neoplasias da Próstata/tratamento farmacológico , Modelos Animais de Doenças
4.
Clin Radiol ; 76(8): 615-620, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34103146

RESUMO

AIM: To assess safety and efficiency of the Cheshire & Merseyside Collaborative, the largest trainee led on-call service in the UK, based on discrepancy rates and time taken to issue reports. MATERIALS & METHODS: All studies reported by the collaborative in a 4-week period were evaluated for discrepancy and the time taken to issue a report. These figures were compared against the Royal College of Radiologists (RCR) guidelines and a recent national audit of discrepancy rates. The time taken to report was measured against the National Institute of Health and Clinical Excellence (NICE) and Trauma Audit Research Network (TARN) guidelines. RESULTS: The overall discrepancy rates for the collaborative were 2.5% for minor discrepancies and 2% for major discrepancies, which is within the RCR standard. The median time taken to issue a report was 30 min, which is within the NICE and TARN 1-h targets. CONCLUSIONS: The Cheshire & Merseyside Collaborative can be deemed a safe and efficient way of delivering an out-of-hours radiology service.


Assuntos
Plantão Médico/métodos , Plantão Médico/estatística & dados numéricos , Competência Clínica/estatística & dados numéricos , Eficiência Organizacional/estatística & dados numéricos , Radiologistas/estatística & dados numéricos , Radiologia/métodos , Humanos , Radiologia/estatística & dados numéricos , Fatores de Tempo , Reino Unido
5.
Front Cell Dev Biol ; 9: 806521, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35096832

RESUMO

The ability of cells to sense diverse environmental signals, including nutrient availability and conditions of stress, is critical for both prokaryotes and eukaryotes to mount an appropriate physiological response. While there is a great deal known about the different biochemical pathways that can detect and relay information from the environment, how these signals are integrated to control progression through the cell cycle is still an expanding area of research. Over the past three decades the proteins Tuberin, Hamartin and TBC1D7 have emerged as a large protein complex called the Tuberous Sclerosis Complex. This complex can integrate a wide variety of environmental signals to control a host of cell biology events including protein synthesis, cell cycle, protein transport, cell adhesion, autophagy, and cell growth. Worldwide efforts have revealed many molecular pathways which alter Tuberin post-translationally to convey messages to these important pathways, with most of the focus being on the regulation over protein synthesis. Herein we review the literature supporting that the Tuberous Sclerosis Complex plays a critical role in integrating environmental signals with the core cell cycle machinery.

6.
Poult Sci ; 99(1): 39-47, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32416824

RESUMO

In a previous study, we demonstrated that a 15% feed restriction (FR) during the first 2 wk after hatch could improve gait in Pekin meat ducks, but did result in reduced breast mass. We hypothesized that feed restriction after day 5 following muscle satellite cell development would allow the full growth of the breast meat. To accomplish this goal, 300 1-day-old ducklings (Maple Leaf Farms Inc.) were randomly allocated to 1 of the 3 groups (n = 4 pens, 25 ducks per pen): (1) Control group fed to ad libitum; (2) 85% daily feed intake from days 1 to 14 (FR 85% 1-14); 85% daily feed intake from days 5 to 14 (FR 85% 5-14). All ducks were vaccinated with inactivated Salmonella enteritidis on day 14 and boosted on day 26. The FR 85% 5-14 did show similar production standards to controls, and improved gait characteristics (P < 0.05). To determine if the partial feed restriction would have an impact on intestinal epithelial tight junction integrity, we treated ducks on days 7, 14, 21, 28, and 35 with 8.32 mg/kg FITC-d in water per os and blood samples were obtained via the tibial vein 1 h later. Serum samples were analyzed for presence and quantification of FITC-d. Feed restriction elicited a significant increase in FITC-d permeability at all points of evaluation. Anti-S. enteritidis specific IgY responses were assessed by ELISA from serum collected at 14 D, 28 D, and 35 D. Although all ducks showed an increase humoral immune response to the S. enteritidis, both feed restricted groups showed reduced IgY production compared to ad lib controls. Our data suggest that although the FR 5-14 feed restriction paradigm may reduce gait abnormalities without affecting production rates, some challenges exist due to increased gut leakiness or decreased acquired immune activity. Future studies will look at altering the feed restriction milieu to ameliorate these challenges.


Assuntos
Ração Animal/análise , Patos/fisiologia , Marcha , Imunidade Humoral , Músculos Peitorais/crescimento & desenvolvimento , Animais , Dieta/veterinária , Patos/crescimento & desenvolvimento , Marcha/efeitos dos fármacos , Imunidade Humoral/efeitos dos fármacos , Carne/análise , Músculos Peitorais/efeitos dos fármacos , Distribuição Aleatória , Fatores de Tempo
7.
Infect Prev Pract ; 2(3): 100073, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34316562

RESUMO

BACKGROUND: Transmission in healthcare settings can result in significant infections in healthcare workers and patients. Understanding infection dynamics has important implications for methods employed in hospitals to prevent nosocomial transmission events. METHODS: In this case series report we describe a cluster of COVID-19 (Coronavirus disease 2019) in a tertiary care university hospital, in the early phases of the epidemic, after hospital visiting had been stopped and when the UK lockdown was in place. FINDINGS: A 48 year old patient developed COVID-19 31 days post-admission and four days after admission to a medical ward from ITU. Infection was likely acquired from an asymptomatic or minimally symptomatic healthcare worker (HCW). Subsequent investigation over a 14 day period revealed symptoms in 23 staff members and five linked cases in patients on the same ward.Nine of the 23 affected staff members provided care for and had direct exposure with the index case. Four staff reported caring for the index case without use of personal protective equipment. One was coughed on directly by the patient 24 hours prior to the onset of symptoms. CONCLUSION: SARS CoV2 infection can be introduced to a ward area by asymptomatic and minimally symptomatic healthcare workers. Staff members and patients can act as Trojan horses carrying infection into and around the hospital, setting up unexpected transmission events.Transmission of infection from pre-symptomatic, asymptomatic and minimally symptomatic individuals means that universal use of measures to prevent transmission is required for successful reduction of transmission events in the hospital setting.

8.
Prev Med ; 121: 128-135, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30771362

RESUMO

This single-blind, pragmatic, cluster randomised controlled trial aims to investigate uptake of children's weight management services in response to enhanced National Child Measurement Programme (NCMP) letters providing weight status feedback to parents in three English counties in 2015. Parents of 2642 overweight or very overweight (obese) children aged 10-11 years received an intervention or control letter informing them of their child's weight status. Intervention letters included (i) a visual tool to help weight status recognition, (ii) a social norms statement, and for very overweight children, (iii) a prepopulated booking form for weight management services. The primary outcome was weight management service enrolment. Additional outcome measures included attendance at and contact made with weight management services, and a number of self-report variables. A small effect was observed, with intervention parents being significantly more likely to enrol their children in weight management services (4.33% of Intervention group) than control parents (2.19% of Control group) in both unadjusted (OR = 2.08, p = .008) and adjusted analyses (AOR = 2.48, p = .001). A similar picture emerged for contact with services (4.80% Intervention vs. 2.41% Control; OR = 2.10, p = .003; AOR = 2.46, p < .001) and attendance at services, although group differences in the latter measure were not significant after corrections for multiple comparisons (1.89% Intervention vs. 1.02% Control; AOR = 2.11, p = .047). No effects were found on self-report variables. Theoretically informed weight status feedback letters appear to be an effective strategy to improve enrolment in paediatric weight management services.


Assuntos
Peso Corporal , Correspondência como Assunto , Promoção da Saúde/métodos , Pais/psicologia , Normas Sociais , Índice de Massa Corporal , Criança , Retroalimentação , Feminino , Humanos , Masculino , Relações Pais-Filho , Obesidade Infantil/prevenção & controle , Inquéritos e Questionários , Reino Unido
9.
Poult Sci ; 97(12): 4262-4271, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29992329

RESUMO

The Pekin duck is an excellent model for the study of seasonal reproduction. To more completely understand the lighting requirements for maximal fertility in duck breeder houses, we housed adult (45 week old) drakes and hens in the Hope College aviary as 5 drakes and 25 hens. Light conditions in each floor pen were normalized based upon quantal energy and divided into the following categories: (1) to simulate summer, 14.5 h 65 lux with 9.5 h 1 lux; (2) to simulate winter, 8 h 65 lux with 16 h 1 lux; (3) winter augmented, 8 h 65 lux with 16 h at 15 lux. The experiment was repeated with rotation of light treatments among 3 pens until a final N = 6 was obtained. Daily, total number of eggs laid was tallied, and a daily average of eggs laid was calculated throughout the study. Weekly, eggs were weighed and the perivitilline membrane was assayed for the number of sperm holes as an indirect measure of drake fertility. As expected, winter conditions caused a reduction in the percent of eggs laid and a reduction in the number of fertilized eggs compared to the summer light conditions. The augmented winter light conditions prevented the loss in the percent eggs laid and fertilized eggs. Surprisingly, even after 4 wk of the study, the winter conditions did not cause a complete loss of fertility in the Pekin ducks. At the end of the study, no differences in the relative expression in brain deep brain photoreceptors or gonadotropin inhibitory hormone mRNAs were observed among any light treatment. Although a minimum (1 lux) of light can support some fertility, our findings suggest commercial Pekin duck barns may benefit from increasing the augmented light to 15 lux to maintain optimal fertility during winter months. Furthermore, our data suggest that drakes may be more sensitive to environmental light conditions than hens.


Assuntos
Criação de Animais Domésticos/métodos , Patos/fisiologia , Fertilidade , Abrigo para Animais , Iluminação , Animais , Feminino , Luz , Masculino , Fatores Sexuais
10.
Appetite ; 124: 111-123, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28479406

RESUMO

Children consume too much sugar and not enough fruit and vegetables, increasing their risk of adverse health outcomes. Inhibitory control training (ICT) reduces children's and adults' intake of energy-dense foods in both laboratory and real-life settings. However, no studies have yet examined whether ICT can increase healthy food choice when energy-dense options are also available. We investigated whether a food-specific Go/No-Go task could influence the food choices of children aged 4-11, as measured by a hypothetical food choice task using healthy and unhealthy food images printed on cards. Participants played either an active game (healthy foods = 100% go, unhealthy foods = 100% no-go; Studies 1 & 2), a food control game (both healthy and unhealthy foods = 50% go, 50% no-go; Studies 1 & 2) or a non-food control game (sports equipment = 100% go, technology = 100% no-go; Study 2 only) followed by the choice task. In Study 2, food card choices were also measured before training to examine change in choices. A post-training real food choice task was added to check that choices made in the card-based task were representative of choices made when faced with real healthy and unhealthy foods. Overall, the active group chose the greatest number of healthy food cards. Study 2 confirmed that this was due to increases in healthy food card choice in this group only. Active group participants chose a greater number of healthy foods in the real food choice task compared to children in the non-food control group only. The results are discussed with reference to methodological issues and the development of future healthy eating interventions.


Assuntos
Comportamento de Escolha , Preferências Alimentares/psicologia , Inibição Psicológica , Lanches , Índice de Massa Corporal , Criança , Pré-Escolar , Dieta/psicologia , Dieta Saudável/psicologia , Ingestão de Alimentos/psicologia , Feminino , Frutas , Humanos , Fome , Masculino , Projetos Piloto , Verduras
11.
Child Care Health Dev ; 44(1): 147-160, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28833334

RESUMO

BACKGROUND: Advocacy has been described by parents of children with autism as an important coping strategy, enabling them to move forward by redirecting emotions into actions. A key factor in the development of collaborative and constructive partnerships between service providers and parents is having an understanding of how parents engage in advocacy and the support needed to do so. This meta-synthesis was undertaken to consolidate in-depth qualitative data from parents' perspectives of the process that they use to advocate for their children with autism. METHODS: A qualitative meta-synthesis was conducted, whereby 15 databases were systematically searched. Thirty-one studies were identified and appraised using an adapted version of the Critical Appraisal Skills Programme tool. Data were synthesized into themes through the steps of review, meta-aggregation, integration, and interpretation. RESULTS: The voices of 1,662 parents are presented describing the process of advocacy in the stages of seeking a diagnosis, seeking self-education, and taking action. Taking action includes 2 subthemes: seeking, access, and use of support services and community engagement and educating others. CONCLUSIONS: Results highlight the significant impact that positive experiences with first-line professionals have during the diagnosis process and how these experiences lay the foundation for all future relationships with other service providers. Important implications arise from this meta-synthesis for service providers in supporting parents' advocacy and hence building constructive relationships with families with a child with autism.


Assuntos
Transtorno do Espectro Autista/psicologia , Defesa da Criança e do Adolescente , Pais/psicologia , Transtorno do Espectro Autista/diagnóstico , Transtorno do Espectro Autista/terapia , Criança , Humanos , Pesquisa Qualitativa , Apoio Social
12.
Paediatr Anaesth ; 27(7): 760-767, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28504322

RESUMO

BACKGROUND: When pain management has been studied in settings such as pediatric emergency departments, racial disparities have been clearly identified. To our knowledge, this has not been studied in the pediatric perioperative setting. We sought to determine whether there are differences based on race in the administration of analgesia to children suffering from pain in the postanesthesia care unit. METHODS: This is a prospective, observational, study of 771 children aged 4-17 years who underwent elective outpatient surgery. Racial differences in probability of receiving analgesia for pain in the recovery room were assessed using bivariable and multivariable logistic regression analyses. RESULTS: A total of 294 children (38.2%) received at least one class of analgesia (opioid or nonopioid); while 210 (27.2%) received intravenous (i.v.) opioid analgesia in the recovery room. Overall postanesthesia care unit analgesia utilization was similar between white and minority children (white children 36.8% vs minority children 43.4%, OR 1.3; 95% CI=0.92-1.89; P=.134). We found no significant difference by racial/ethnic group in the likelihood of a child receiving i.v. opioid for severe postoperative pain (white children 76.0% vs 85.7%, OR 1.89; 95% CI=0.37-9.67; P=.437). However, minority children were more likely to receive i.v. opioid analgesia than their white peers (white children 24.5% vs minority children 34.2%, OR 1.5; 95% CI=1.04-2.2; P=.03). On multivariable analysis, minority children had a 63% higher adjusted odds of receiving i.v. opioids in the recovery room (OR=1.63; 95% CI, 1.05-2.62; P=.03). CONCLUSIONS: Receipt of analgesia for acute postoperative pain was not significantly associated with a child's race. Minority children were more likely to receive i.v. opioids for the management of mild pain.


Assuntos
Período de Recuperação da Anestesia , Etnicidade , Manejo da Dor/métodos , Dor Pós-Operatória/terapia , Administração Intravenosa , Adolescente , Procedimentos Cirúrgicos Ambulatórios , Analgésicos/uso terapêutico , Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/uso terapêutico , Criança , Pré-Escolar , Procedimentos Cirúrgicos Eletivos , Feminino , Disparidades em Assistência à Saúde , Humanos , Lactente , Masculino , Manejo da Dor/estatística & dados numéricos , Estudos Prospectivos , População Branca
13.
Clin Exp Allergy ; 47(6): 770-784, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28000962

RESUMO

BACKGROUND: Inflamed environments are typically hypercellular, rich in pro-inflammatory cytokines, and profoundly hypoxic. While the effects of hypoxia on neutrophil longevity and function have been widely studied, little is known about the consequences of this stimulus on eosinophils. OBJECTIVE: We sought to investigate the effects of hypoxia on several key aspects of eosinophil biology, namely secretion, survival, and their sensitivity to glucocorticosteroids (GCS), agents that normally induce eosinophil apoptosis. METHODS: Eosinophils derived from patients with asthma/atopy or healthy controls were incubated under normoxia and hypoxia, with or without glucocorticoids. Activation was measured by flow cytometry, ELISA of cultured supernatants, and F-actin staining; apoptosis and efferocytosis by morphology and flow cytometry; and GCS efficacy by apoptosis assays and qPCR. RESULTS: Hypoxic incubation (3 kPa) caused (i) stabilization of HIF-2α and up-regulation of hypoxia-regulated genes including BNIP3 (BCL2/adenovirus E1B 19-kDa protein-interacting protein 3) and GLUT1 (glucose transporter 1); (ii) secretion of pre-formed IL-8, and Charcot Leyden crystal (CLC) formation, which was most evident in eosinophils derived from atopic and asthmatic donors; (iii) enhanced F-actin formation; (iv) marked prolongation of eosinophil lifespan (via a NF-κB and Class I PI3-kinase-dependent mechanism); and (v) complete abrogation of the normal pro-apoptotic effect of dexamethasone and fluticasone furoate. This latter effect was evident despite preservation of GCS-mediated gene transactivation under hypoxia. CONCLUSION AND CLINICAL RELEVANCE: These data indicate that hypoxia promotes an eosinophil pro-inflammatory phenotype by enhancing eosinophil secretory function, delaying constitutive apoptosis, and importantly, antagonizing the normal pro-apoptotic effect of GCS. As eosinophils typically accumulate at sites that are relatively hypoxic, particularly during periods of inflammation, these findings may have important implications to understanding the behaviour of these cells in vivo.


Assuntos
Hipóxia Celular/fisiologia , Eosinófilos/patologia , Interleucina-8/metabolismo , Anti-Inflamatórios/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Células Cultivadas , Dexametasona/farmacologia , Eosinófilos/efeitos dos fármacos , Eosinófilos/metabolismo , Glucocorticoides/farmacologia , Humanos , Corpos de Inclusão/patologia , Inflamação/imunologia , Inflamação/patologia
14.
Child Care Health Dev ; 42(6): 784-797, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27445227

RESUMO

Parenting a child with autism spectrum disorder (ASD) can be stressful, and accessing services can add to this stress. Self-efficacy, agency and advocacy are important for parents when accessing and using services. To develop insight into parental advocacy, a meta-synthesis was undertaken to consolidate the literature focussing on parents' experiences of advocating for their child with ASD. A qualitative meta-synthesis was conducted. Fifteen databases were systematically searched by using key terms related to ASD, children, parents/carers, advocacy and qualitative studies. Twenty-four studies were identified and appraised using an adapted version of the Critical Appraisal Skills Programme tool. Data were synthesized into themes through the steps of review, meta-aggregation, integration and interpretation. Two overarching concepts emerged, illustrating both the challenging nature of advocacy and the associated personal and societal benefits. These two concepts are supported by eight themes: a life-long, all-encompassing challenge; advocacy as a parental coping strategy; advocacy involving working to create a future; balancing roles and needs; isolation versus support; personal impacts of advocacy; benefits of advocacy; and the barriers to advocacy. The experience of advocacy for parents with a child with ASD is complex and intensive, presenting both personal and societal benefits, as well as challenges for parents. In supporting individuals with ASD and family well-being, service providers need to have an understanding of the advocating role of parents and ensure that opportunities exist for their voices to be heard during service delivery.


Assuntos
Transtorno do Espectro Autista/psicologia , Defesa da Criança e do Adolescente , Pais/psicologia , Adaptação Psicológica , Atitude Frente a Saúde , Transtorno do Espectro Autista/reabilitação , Criança , Humanos , Poder Familiar , Pesquisa Qualitativa , Apoio Social
15.
J Chem Phys ; 144(8): 084704, 2016 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-26931715

RESUMO

The structural properties of a-HfO2/Ge(2 × 1)-(001) and a-ZrO2/Ge(2 × 1)-(001) interfaces were investigated with and without a GeOx interface interlayer using density-functional theory (DFT) molecular dynamics (MD) simulations. Realistic a-HfO2 and a-ZrO2 samples were generated using a hybrid classical-DFT MD "melt-and-quench" approach and tested against experimental properties. The oxide/Ge stacks were annealed at 700 K, cooled to 0 K, and relaxed providing the system with enough freedom to form realistic interfaces. For each high-K/Ge stack type, two systems with single and double interfaces were investigated. All stacks were free of midgap states; however, stacks with a GeO(x) interlayer had band-edge states which decreased the band gaps by 0%-30%. These band-edge states were mainly produced by under-coordinated Ge atoms in GeO(x) layer or its vicinity due to deformation, intermixing, and bond-breaking. The DFT-MD simulations show that electronically passive interfaces can be formed either directly between high-K dielectrics and Ge or with a monolayer of GeO2 if the processing does not create or properly passivate under-coordinated Ge atoms and Ge's with significantly distorted bonding angles. Comparison to the charge states of the interfacial atoms from DFT to experimental x-ray photoelectron spectroscopy results shows that while most studies of gate oxide on Ge(001) have a GeO(x) interfacial layer, it is possible to form an oxide/Ge interface without a GeO(x) interfacial layer. Comparison to experiments is consistent with the dangling bonds in the suboxide being responsible for midgap state formation.

16.
Am J Primatol ; 78(3): 298-314, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25573250

RESUMO

Tamarins are reported to live in small multimale-multifemale groups characterized by a single breeding female. Here we present information on the composition and genetic relatedness of individuals in 12 wild-trapped groups of Weddell's saddleback tamarins (Saguinus weddelli) from northern Bolivia to determine if groups are best described as nuclear or extended families suggesting social monogamy or whether groups contain several unrelated same sex adults indicative of social polyandry/polygyny. Mean group size was 6.25 including an average of 2.16 adult males (range 1-4) and 2.08 adult females (1-3). No group contained only one adult male and one adult female and 25% of groups contained two parous females. We estimated the genetic relatedness among individuals using 13 polymorphic microsatellite markers. Across the population, mean relatedness was low and not significantly different among adult males versus among adult females, suggesting that both sexes disperse from their natal groups. Adults of both sexes also tended to have close same-sex adult relatives within their groups; relatedness among adult females of the same group averaged 0.31 and among adult males was 0.26. This suggests that tamarins of one or both sexes sometimes delay dispersal and remain as adults in their natal group or that emigration of same-sexed relatives into the same group may be common. Finally, parentage analyses indicated that, whereas the parents of juveniles generally were present in the group, this was not always the case. Based on these data, published reports of the presence of multiple breeding males and occasionally multiple breeding females in the same group, and the fact that less than 10% of groups in the wild contain a single adult male-adult female pair, we argue that social polyandry best characterizes the composition of tamarin groups and that monogamy is not a common mating pattern in Saguinus weddelli or other tamarin species.


Assuntos
Ligação do Par , Reprodução , Saguinus/fisiologia , Comportamento Social , Animais , Bolívia , Feminino , Masculino , Repetições de Microssatélites , Saguinus/genética
17.
Neuroscience ; 316: 41-52, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26705739

RESUMO

Previous studies have indicated that sodium salicylate (SS) can cause hearing abnormalities through affecting the central auditory system. In order to understand central effects of the drug, we examined how a single intraperitoneal injection of the drug changed the level of subunits of the type-B γ-aminobutyric acid receptor (GABAB receptor) in the rat's inferior colliculus (IC). Immunohistochemical and western blotting experiments were conducted three hours following a drug injection, as previous studies indicated that a tinnitus-like behavior could be reliably induced in rats within this time period. Results revealed that both subunits of the receptor, GABABR1 and GABABR2, reduced their level over the entire area of the IC. Such a reduction was observed in both cell body and neuropil regions. In contrast, no changes were observed in other brain structures such as the cerebellum. Thus, a coincidence existed between a structure-specific reduction in the level of GABAB receptor subunits in the IC and the presence of a tinnitus-like behavior. This coincidence likely suggests that a reduction in the level of GABAB receptor subunits was involved in the generation of a tinnitus-like behavior and/or used by the nervous system to restore normal hearing following application of SS.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Colículos Inferiores/efeitos dos fármacos , Receptores de GABA-B/metabolismo , Salicilato de Sódio/farmacologia , Animais , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Tubulina (Proteína)/metabolismo
18.
Insect Mol Biol ; 24(5): 539-50, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26108887

RESUMO

Silencing Amblyomma americanum insulin-like growth factor binding protein-related protein 1 (AamIGFBP-rP1) mRNA prevented ticks from feeding to repletion. In this study, we used recombinant (r)AamIGFBP-rP1 in a series of assays to obtain further insight into the role(s) of this protein in tick feeding regulation. Our results suggest that AamIGFBP-1 is an antigenic protein that is apparently exclusively expressed in salivary glands. We found that both males and females secrete AamIGFBP-rP1 into the host during feeding and confirmed that female ticks secrete this protein from within 24-48 h after attachment. Our data suggest that native AamIGFBP-rP1 is a functional insulin binding protein in that both yeast- and insect cell-expressed rAamIGFBP-rP1 bound insulin, but not insulin-like growth factors. When subjected to anti-blood clotting and platelet aggregation assays, rAamIGFBP-rP1 did not have any effect. Unlike human IGFBP-rP1, which is controlled by trypsinization, rAamIGFBP-rP1 is resistant to digestion, suggesting that the tick protein may not be under mammalian host control at the tick feeding site. The majority of tick-borne pathogens are transmitted 48 h after the tick has attached. Thus, the demonstrated antigenicity and secretion into the host within 24-48 h of the tick starting to feed makes AamIGFBP-rP1 an attractive target for antitick vaccine development.


Assuntos
Antígenos/metabolismo , Proteínas de Artrópodes/metabolismo , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/metabolismo , Insulina/metabolismo , Ixodidae/metabolismo , Somatomedinas/metabolismo , Sequência de Aminoácidos , Animais , Antígenos/imunologia , Antígenos/farmacologia , Proteínas de Artrópodes/imunologia , Proteínas de Artrópodes/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Bovinos , Feminino , Humanos , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/imunologia , Ixodidae/imunologia , Lepidópteros , Masculino , Dados de Sequência Molecular , Pichia , Agregação Plaquetária/efeitos dos fármacos , Ligação Proteica , Coelhos/parasitologia , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologia , Saliva/metabolismo , Células Sf9
19.
Cell Death Differ ; 22(9): 1540-50, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25744025

RESUMO

Prelamin A accumulation and persistent DNA damage response (DDR) are hallmarks of vascular smooth muscle cell (VSMC) ageing and dysfunction. Although prelamin A is proposed to interfere with DNA repair, our understanding of the crosstalk between prelamin A and the repair process remains limited. The extracellular signal-regulated kinases 1 and 2 (ERK1/2) have emerged as key players in the DDR and are known to enhance ataxia telangiectasia-mutated protein (ATM) activity at DNA lesions, and in this study, we identified a novel relationship between prelamin A accumulation and ERK1/2 nuclear compartmentalisation during VSMC ageing. We show both prelamin A accumulation and increased DNA damage occur concomitantly, before VSMC replicative senescence, and induce the localisation of ERK1/2 to promyelocytic leukaemia protein nuclear bodies (PML NBs) at the sites of DNA damage via nesprin-2 and lamin A interactions. Importantly, VSMCs treated with DNA damaging agents also displayed prelamin A accumulation and ERK compartmentalisation at PML NBs, suggesting that prelamin A and nesprin-2 are novel components of the DDR. In support of this, disruption of ERK compartmentalisation at PML NBs, by either depletion of nesprin-2 or lamins A/C, resulted in the loss of ATM from DNA lesions. However, ATM signalling and DNA repair remained intact after lamins A/C depletion, whereas nesprin-2 disruption ablated downstream Chk2 activation and induced genomic instability. We conclude that lamins A/C and PML act as scaffolds to organise DNA-repair foci and compartmentalise nesprin-2/ERK signalling. However, nesprin-2/ERK signalling fidelity, but not their compartmentalisation at PML NBs, is essential for efficient DDR in VSMCs.


Assuntos
Dano ao DNA , Proteínas dos Microfilamentos/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Músculo Liso Vascular/citologia , Músculo Liso Vascular/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas Nucleares/metabolismo , Adulto , Ciclo Celular/fisiologia , Senescência Celular/fisiologia , Reparo do DNA , Feminino , Humanos , Corpos de Inclusão Intranuclear/genética , Corpos de Inclusão Intranuclear/metabolismo , Lamina Tipo A/metabolismo , Masculino , Proteínas dos Microfilamentos/genética , Pessoa de Meia-Idade , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/genética , Músculo Liso Vascular/enzimologia , Proteínas do Tecido Nervoso/genética , Proteínas Nucleares/genética , Transfecção , Adulto Jovem
20.
Heredity (Edinb) ; 113(4): 353-63, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24781807

RESUMO

The occurrence and frequency of outcrossing in homothallic fungal species in nature is an unresolved question. Here we report detection of frequent outcrossing in the homothallic fungus Sclerotinia sclerotiorum. In using multilocus linkage disequilibrium (LD) to infer recombination among microsatellite alleles, high mutation rates confound the estimates of recombination. To distinguish high mutation rates from recombination to infer outcrossing, 8 population samples comprising 268 S. sclerotiorum isolates from widely distributed agricultural fields were genotyped for 12 microsatellite markers, resulting in multiple polymorphic markers on three chromosomes. Each isolate was homokaryotic for the 12 loci. Pairwise LD was estimated using three methods: Fisher's exact test, index of association (IA) and Hedrick's D'. For most of the populations, pairwise LD decayed with increasing physical distance between loci in two of the three chromosomes. Therefore, the observed recombination of alleles cannot be simply attributed to mutation alone. Different recombination rates in various DNA regions (recombination hot/cold spots) and different evolutionary histories of the populations could explain the observed differences in rates of LD decay among the chromosomes and among populations. The majority of the isolates exhibited mycelial incompatibility, minimizing the possibility of heterokaryon formation and mitotic recombination. Thus, the observed high intrachromosomal recombination is due to meiotic recombination, suggesting frequent outcrossing in these populations, supporting the view that homothallism favors universal compatibility of gametes instead of traditionally believed haploid selfing in S. sclerotiorum. Frequent outcrossing facilitates emergence and spread of new traits such as fungicide resistance, increasing difficulties in managing Sclerotinia diseases.


Assuntos
Ascomicetos/genética , Desequilíbrio de Ligação , Ascomicetos/fisiologia , Variação Genética , Hibridização Genética , Repetições de Microssatélites , Recombinação Genética
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