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1.
Environ Microbiol ; 24(8): 3390-3404, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35641308

RESUMO

Fine root endophyte mycorrhizal fungi in the Endogonales (Mucoromycota arbuscular mycorrhizal fungi, M-AMF) are now recognized as at least as important globally as Glomeromycota AMF (G-AMF), yet little is known about the environmental factors which influence M-AMF diversity and colonization, partly because they typically only co-colonize plants with G-AMF. Wild populations of Lycopodiella inundata predominantly form mycorrhizas with M-AMF and therefore allow focussed study of M-AMF environmental drivers. Using microscopic examination and DNA sequencing we measured M-AMF colonization and diversity over three consecutive seasons and modelled interactions between these response variables and environmental data. Significant relationships were found between M-AMF colonization and soil S, P, C:N ratio, electrical conductivity, and the previously overlooked micronutrient Mn. Estimated N deposition was negatively related to M-AMF colonization. Thirty-nine Endogonales Operational Taxonomic Units (OTUs) were identified in L. inundata roots, a greater diversity than previously recognized in this plant. Endogonales OTU richness correlated negatively with soil C:N while community composition was mostly influenced by soil P. This study provides first evidence that M-AMF have distinct ecological preferences in response to edaphic variables also related to air pollution. Future studies require site-level atmospheric pollution monitoring to guide critical load policy for mycorrhizal fungi in heathlands and grasslands.


Assuntos
Glomeromycota , Micorrizas , Poluição Ambiental , Fungos/fisiologia , Glomeromycota/genética , Micorrizas/genética , Nutrientes , Raízes de Plantas/microbiologia , Plantas , Solo , Microbiologia do Solo
2.
Adv Exp Med Biol ; 1395: 89-93, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36527619

RESUMO

There may be a relationship between hypoxia and inflammation, which is important in the outcomes of a wide array of human diseases. Multiple sclerosis (MS) is one such disease. There is evidence that hypoxia may influence inflammation in MS. We showed previously that about 40% of participants with MS had hypoxia in the cortical grey matter using frequency-domain near-infrared spectroscopy (fdNIRS). In this study, we aimed to determine if hypoxia in MS persists chronically (for a year or more) by measuring at baseline and ≥12 months later. We found that hypoxia persists for at least a year in 80% of participants with MS. As more individuals remained hypoxic than returned to normoxia, the development of hypoxia may relate to disease progression.


Assuntos
Esclerose Múltipla , Humanos , Esclerose Múltipla/diagnóstico por imagem , Espectroscopia de Luz Próxima ao Infravermelho , Hipóxia , Progressão da Doença , Inflamação/diagnóstico por imagem
3.
J Environ Manage ; 290: 112589, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33906116

RESUMO

Agri-environment schemes (AES) are key mechanisms to deliver conservation policy, and include management to provide resources for target taxa. Mobile species may move to areas where resources are increased, without this necessarily having an effect across the wider countryside or on populations over time. Most assessments of AES efficacy have been at small spatial scales, over short timescales, and shown varying results. We developed a survey design based on orthogonal gradients of AES management at local and landscape scales, which will enable the response of several taxa to be monitored. An evidence review of management effects on butterflies, birds and pollinating insects provided data to score AES options. Predicted gradients were calculated using AES uptake, weighted by the evidence scores. Predicted AES gradients for each taxon correlated strongly, and with the average gradient across taxa, supporting the co-location of surveys across different taxa. Nine 1 × 1 km survey squares were selected in each of four regional blocks with broadly homogenous background habitat characteristics. Squares in each block covered orthogonal contrasts across the range of AES gradients at local and landscape scales. This allows the effects of AES on species at each scale, and the interaction between scales, to be tested. AES options and broad habitats were mapped in field surveys, to verify predicted gradients which were based on AES option uptake data. The verified AES gradient had a strong positive relationship with the predicted gradient. AES gradients were broadly independent of background habitat within each block, likely allowing AES effects to be distinguished from potential effects of other habitat variables. Surveys of several mobile taxa are ongoing. This design will allow mobile taxa responses to AES to be tested in the surrounding countryside, as well as on land under AES management, and potentially in terms of population change over time. The design developed here provides a novel, pseudo-experimental approach for assessing the response of mobile species to gradients of management at two spatial scales. A similar design process could be applied in other regions that require a standardized approach to monitoring the impacts of management interventions on target taxa at landscape scales, if equivalent spatial data are available.


Assuntos
Agricultura , Borboletas , Animais , Biodiversidade , Aves , Ecossistema , Meio Ambiente
4.
Int J Obes (Lond) ; 44(9): 1958-1969, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32678325

RESUMO

Diet has important effects on normal physiology and the potential deleterious effects of high fat diets and obesity on male reproductive health are being increasingly described. We conducted a histological review of the effects of chronic high fat (HF) diet (using a mouse model fed a 45% fat diet for 21 weeks) with a discovery proteomic study to assess for changes in the abundance of proteins in the testis. Mice on a HF diet became obese and developed glucose intolerance. Using mass spectrometry, we identify 102 proteins affected in the testis of obese mice. These included structural proteins important for the blood testis barrier (filamin A, FLNA), proteins involved in oxidative stress responses (spermatogenesis associated 20, SPATA-20) and lipid homoeostasis (sterol regulatory element-binding protein 2, SREBP2 and apolipoprotein A1, APOA1). In addition, an important regulator protein paraspeckle component 1, PSPC-1, which interacts with the androgen receptor was significantly downregulated. Proteomic data was validated using both Western blotting and immunostaining which confirmed and localised protein expression in both mouse and human testis using biopsy specimens. This study focused mainly on the abnormalities that occurred at the protein level and as a result, we have identified several candidate proteins and conducted pathway analysis around the effects of HF diet on the testis providing novel insights not previously described. Some of the identified targets could be targeted therapeutically and future work is directed in this area.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Gorduras na Dieta/farmacologia , Obesidade/metabolismo , Proteoma/efeitos dos fármacos , Testículo , Animais , Humanos , Masculino , Camundongos , Testículo/efeitos dos fármacos , Testículo/patologia
5.
BJOG ; 127(7): 876-884, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32012415

RESUMO

OBJECTIVE: To determine maternal, obstetric and neonatal outcomes in a cohort of women with primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC). DESIGN: Retrospective cohort study. SETTING: Ten specialist centres managing pregnant women with liver disease. POPULATION: Women with a diagnosis of PBC and PSC and a pregnancy of ≥20 completed weeks of gestation. METHODS: Retrospective case notes review. MAIN OUTCOME MEASURES: Adverse outcomes were defined as: maternal - development of ascites, variceal bleeding, encephalopathy and jaundice; obstetric events - gestational hypertension, pre-eclampsia and postpartum haemorrhage; and neonatal - stillbirth, preterm delivery and admission to neonatal unit. The relationship of alanine transferase (ALT) and bile acid levels with gestation at delivery was studied. RESULTS: The first recorded pregnancies of 34 women with PSC and 27 women with PBC were analysed. There were 60 live births and one intrapartum stillbirth that did not occur in the context of maternal cholestasis. The overall median gestation of delivery was 38 weeks but the rate of preterm birth was 28% (17/61 deliveries), 76% (13/17) of which were spontaneous. Gestation at birth negatively correlated with maternal serum ALT concentration at booking (P = 0.017) and serum bile acid concentration during pregnancy (P = 0.016). There were no other significant correlations and maternal and neonatal outcomes were good. CONCLUSIONS: Pregnancy in PBC and PSC is well tolerated, but women should be counselled regarding the increased risk of preterm birth. Measurement of maternal ALT and bile acids may help identify women at risk of preterm delivery. TWEETABLE ABSTRACT: Pregnancy in women with PBC and PSC is well tolerated; however, rates of preterm birth are high and are related to maternal bile acid levels.


Assuntos
Colangite Esclerosante , Cirrose Hepática Biliar , Complicações na Gravidez , Nascimento Prematuro , Adulto , Colangite Esclerosante/complicações , Colangite Esclerosante/diagnóstico , Colangite Esclerosante/epidemiologia , Feminino , Humanos , Recém-Nascido , Cirrose Hepática Biliar/complicações , Cirrose Hepática Biliar/diagnóstico , Cirrose Hepática Biliar/epidemiologia , Testes de Função Hepática/métodos , Gravidez , Complicações na Gravidez/diagnóstico , Complicações na Gravidez/epidemiologia , Resultado da Gravidez/epidemiologia , Nascimento Prematuro/etiologia , Nascimento Prematuro/prevenção & controle , Estudos Retrospectivos , Medição de Risco , Reino Unido/epidemiologia
6.
Public Health ; 174: 110-117, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31326760

RESUMO

OBJECTIVES: Without urgent action, climate change will put the health of future populations at risk. Policies to reduce these risks require support from today's populations; however, there are few studies assessing public support for such policies. Willingness to pay (WtP), a measure of the maximum a person is prepared to pay for a defined benefit, is widely used to assess public support for policies. We used WtP to investigate whether there is public support to reduce future health risks from climate change and if individual and contextual factors affect WtP, including perceptions of the seriousness of the impacts of climate change. STUDY DESIGN: A cross-sectional British survey. METHODS: Questions about people's WtP for policies to reduce future climate change-related deaths and their perceptions of the seriousness of climate change impacts were included in a British survey of adults aged 16 years and over (n=1859). We used contingent valuation, a survey-based method for eliciting WtP for outcomes like health which do not have a direct market value. RESULTS: The majority (61%) were willing to pay to reduce future increases in climate change-related deaths in Britain. Those regarding climate change impacts as not at all serious were less willing to pay than those regarding the impacts as extremely serious (OR 0.04, 95% CI 0.02-0.09). Income was also related to WtP; the highest-income group were twice as likely to be willing to pay as the lowest-income group (OR 2.14, 95% CI 1.40-3.29). CONCLUSIONS: There was public support for policies to address future health impacts of climate change; the level of support varied with people's perceptions of the seriousness of these impacts and their financial circumstances. Our study adds to evidence that health, including the health of future populations, is an outcome that people value and suggests that framing climate change around such values may help to accelerate action.


Assuntos
Mudança Climática/mortalidade , Política de Saúde/economia , Saúde Pública , Adulto , Estudos Transversais , Feminino , Previsões , Humanos , Masculino , Inquéritos e Questionários , Reino Unido/epidemiologia
7.
Br J Anaesth ; 121(2): 453-461, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30032885

RESUMO

BACKGROUND: Propofol is used to induce deep sedation or general anaesthesia for procedures in children. Adjuvants, such as ketamine, are routinely added to reduce the dose of propofol required and propofol-related adverse events. We conducted a randomised controlled trial to determine the effective bolus dose of propofol in combination with ketamine that induces adequate depth of anaesthesia in 50% of children (ED50) undergoing gastro-duodenoscopy. METHODS: Children were randomised to one of four doses of ketamine: 0 (control), 0.25, 0.5, and 1 mg kg-1, followed by a dose of propofol according to Dixon's up-and-down methodology. Excessive movement, coughing, gagging, or airway obstruction that prevented endoscope insertion was considered a failure. RESULTS: The ED50 of propofol (median, 95% CI) was greater in the ketamine 0, 0.25, and 0.5 mg kg-1 groups compared with the ketamine 1 mg kg-1 group (6.1, 4.1-8.1; 4.5, 2.9-6; 4.7, 3.1-6.2 mg kg-1vs 1.1, 0.5-1.8 mg kg-1, respectively, P<0.008). Total dose of propofol administered during the procedure was reduced with ketamine 1 mg kg-1. The mean arterial pressure was lower in the ketamine 0 mg kg-1 group compared with the 1 mg kg-1 group during and immediately after the procedure. The ketamine 1 mg kg-1 group experienced a higher incidence of nausea and visual disturbances. CONCLUSIONS: Ketamine at 0.5-1 mg kg-1 reduces the dose of propofol required to provide general anaesthesia for gastro-duodenoscopy in children and may reduce the incidence of propofol-related changes in haemodynamics. CLINICAL TRIAL REGISTRATION: NCT 02295553.


Assuntos
Anestésicos Dissociativos/administração & dosagem , Anestésicos Intravenosos/administração & dosagem , Endoscopia Gastrointestinal/métodos , Ketamina/administração & dosagem , Propofol/administração & dosagem , Adolescente , Período de Recuperação da Anestesia , Anestésicos Dissociativos/efeitos adversos , Anestésicos Intravenosos/efeitos adversos , Pressão Arterial/efeitos dos fármacos , Criança , Relação Dose-Resposta a Droga , Método Duplo-Cego , Duodenoscopia/métodos , Feminino , Gastroscopia/métodos , Humanos , Intubação Intratraqueal , Ketamina/efeitos adversos , Masculino , Náusea/induzido quimicamente , Náusea/epidemiologia , Propofol/efeitos adversos , Transtornos da Visão/induzido quimicamente , Transtornos da Visão/epidemiologia
8.
Eur J Cancer Care (Engl) ; 27(2): e12820, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29337398

RESUMO

Clinical trials of adjuvant endocrine therapy in women with early breast cancer have consistently reported that genitourinary symptoms are common. However, little is known about women's experiences of genitourinary symptoms, their views about the symptoms and how they impact on their lives. The aim of this study was to explore knowledge, attitudes and experiences of genitourinary symptoms among women receiving adjuvant endocrine therapy for early breast cancer. Thirty-two semi-structured interviews were conducted and subjected to a rigorous qualitative analysis. Genitourinary symptoms were commonly reported to negatively impact on personal, social and physical activities, were often attributed to anxiety and stress and were a source of embarrassment. Women also commented on the limited information available or provided regarding the potential genitourinary adverse effects of adjuvant endocrine therapy. There was a general lack of awareness that their symptoms could be associated with or exacerbated by adjuvant endocrine therapy. Women indicated a preference to receive information and advice about potential management options from either their general practitioner or specialist. These findings underscore the importance of improving communication and increasing awareness among both clinicians and patients about the potential impact of adjuvant endocrine therapy on genitourinary symptoms.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/psicologia , Doenças Urogenitais Femininas/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Adulto , Idoso , Ansiedade/etiologia , Atitude Frente a Saúde , Neoplasias da Mama/tratamento farmacológico , Quimioterapia Adjuvante , Feminino , Comportamento de Busca de Ajuda , Humanos , Acontecimentos que Mudam a Vida , Pessoa de Meia-Idade , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Autorrelato , Disfunções Sexuais Fisiológicas/etiologia , Incontinência Urinária/psicologia
9.
J Eur Acad Dermatol Venereol ; 32(12): 2200-2207, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29730888

RESUMO

BACKGROUND: Therapeutic advances have made the achievement of clear/almost clear skin possible for many patients with moderate-to-severe plaque psoriasis. OBJECTIVE: To determine patient perceptions of the impact of psoriasis and of attaining clear/almost clear skin. METHODS: Global survey of patients with moderate-to-severe psoriasis. RESULTS: A total of 8338 patients from 31 countries participated. The majority (57%) had not achieved self-assessed clear/almost clear skin with their current therapy, and 56% of those who had not met this goal believed it would be impossible to do so. Among the patients who had clear/almost clear skin, 73% had not initiated their current treatment until >1 year after psoriasis diagnosis, and 28% had to wait >5 years. Eighty-four percent of all respondents experienced discrimination and/or humiliation due to psoriasis, and many reported negative effects on work, intimate relationships, sleep and mental health. Patients without clear/almost clear skin reported that such achievement would open new possibilities, such as swimming (58%), a wider choice of clothing (40%), and meeting new people (26%). A limitation of this study, as with any survey-based research, is that selection and recall bias may have been present. Additionally, respondent definitions of clear/almost clear skin were subjective and may have varied. CONCLUSION: Despite the importance of clear/almost clear skin to psoriasis patients, most are still not achieving it, and many are unaware it is possible.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Percepção , Psoríase/psicologia , Adulto , Feminino , Humanos , Internacionalidade , Masculino , Pessoa de Meia-Idade , Psoríase/tratamento farmacológico , Qualidade de Vida , Índice de Gravidade de Doença , Discriminação Social , Inquéritos e Questionários , Resultado do Tratamento
10.
Br J Surg ; 103(10): 1385-93, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27487317

RESUMO

BACKGROUND: The National Early Warning Score (NEWS) is used to identify deteriorating patients in hospital. NEWS is a better discriminator of outcomes than other early warning scores in acute medical admissions, but it has not been evaluated in a surgical population. The study aims were to evaluate the ability of NEWS to discriminate cardiac arrest, death and unanticipated ICU admission in patients admitted to surgical specialties, and to compare the performance of NEWS in admissions to medical and surgical specialties. METHODS: Hospitalwide data over 31 months, from adult inpatients who stayed at least one night or died on the day of admission, were analysed. The data were categorized as elective or non-elective surgical or medical admissions. The ability of NEWS to discriminate the outcomes above in these different groups was assessed using the area under the receiver operating characteristic curve (AUROC). RESULTS: There were too few outcomes to permit meaningful comparison of elective admissions, so the analysis was constrained to comparison of non-elective admissions. NEWS performed equally well, or better, for surgical as for medical patients. For death within 24 h the AUROC for surgical admissions was 0·914 (95 per cent c.i. 0·907 to 0·922), compared with 0·902 (0·898 to 0·905) for medical admissions. For the combined outcome of any of death, cardiac arrest or unanticipated ICU admission, the AUROC was 0·874 (0·868 to 0·880) for surgical admissions and 0·874 (0·871 to 0·877) for medical admissions. CONCLUSION: NEWS discriminated deterioration in non-elective surgical patients at least as well as in non-elective medical patients.


Assuntos
Departamentos Hospitalares , Hospitalização , Índice de Gravidade de Doença , Adulto , Área Sob a Curva , Emergências , Parada Cardíaca/diagnóstico , Mortalidade Hospitalar , Humanos , Unidades de Terapia Intensiva/estatística & dados numéricos , Admissão do Paciente/estatística & dados numéricos , Prognóstico , Curva ROC , Medição de Risco , Centro Cirúrgico Hospitalar , Reino Unido , Sinais Vitais
12.
Nanotechnology ; 24(17): 175102, 2013 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-23571459

RESUMO

Amyloid fibres displaying cytochrome b562 were probed using scanning tunnelling microscopy (STM) in vacuo. The cytochromes are electron transfer proteins containing a haem cofactor and could, in principle, mediate electron transfer between the tip and the gold substrate. If the core fibres were insulating and electron transfer within the 3D haem network was detected, then the electron transport properties of the fibre could be controlled by genetic engineering. Three kinds of STM images were obtained. At a low bias (<1.5 V) the fibres appeared as regions of low conductivity with no evidence of cytochrome mediated electron transfer. At a high bias, stable peaks in tunnelling current were observed for all three fibre species containing haem and one species of fibre that did not contain haem. In images of this kind, some of the current peaks were collinear and spaced around 10 nm apart over ranges longer than 100 nm, but background monomers complicate interpretation. Images of the third kind were rare (1 in 150 fibres); in these, fully conducting structures with the approximate dimensions of fibres were observed, suggesting the possibility of an intermittent conduction mechanism, for which a precedent exists in DNA. To test the conductivity, some fibres were immobilized with sputtered gold, and no evidence of conduction between the grains of gold was seen. In control experiments, a variation of monomeric cytochrome b562 was not detected by STM, which was attributed to low adhesion, whereas a monomeric multi-haem protein, GSU1996, was readily imaged. We conclude that the fibre superstructure may be intermittently conducting, that the cytochromes have been seen within the fibres and that they are too far apart for detectable current flow between sites to occur. We predict that GSU1996, being 10 nm long, is more likely to mediate successful electron transfer along the fibre as well as being more readily detectable when displayed from amyloid.


Assuntos
Amiloide/química , Amiloide/ultraestrutura , Grupo dos Citocromos b/ultraestrutura , Microscopia de Tunelamento/métodos , Grupo dos Citocromos b/química , Grupo dos Citocromos c/química , Grupo dos Citocromos c/ultraestrutura , Condutividade Elétrica , Geobacter/química , Geobacter/enzimologia , Modelos Moleculares
13.
BJOG ; 120(1): 85-91, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23095012

RESUMO

OBJECTIVE: To estimate the incidence of multiple repeat caesarean section (MRCS) (five or more) in the UK and to describe the outcomes for women and their babies relative to women having fewer repeat caesarean sections. DESIGN: A national population-based prospective cohort study using the UK Obstetric Surveillance System (UKOSS). SETTING: All UK hospitals with consultant-led maternity units. POPULATION: Ninety-four women having their fifth or greater MRCS between January 2009 and December 2009, and 175 comparison women having their second to fourth caesarean section. METHODS: Prospective cohort and comparison identification through the UKOSS monthly mailing system. MAIN OUTCOME MEASURES: Incidence, maternal and neonatal complications. Relative risk, unadjusted (OR) and adjusted (aOR) odds ratio estimates. RESULTS: The estimated UK incidence of MRCS was 1.20 per 10 000 maternities [95% confidence interval (CI), 0.97-1.47]. Women with MRCS had significantly more major obstetric haemorrhages (>1500 ml) (aOR, 18.6; 95% CI, 3.89-88.8), visceral damage (aOR, 17.6; 95% CI, 1.85-167.1) and critical care admissions (aOR, 15.5; 95% CI, 3.16-76.0), than women with lower order repeat caesarean sections. These risks were greatest in the 18% of women with MRCS who also had placenta praevia or accreta. Neonates of mothers having MRCS were significantly more likely to be born prior to 37 weeks of gestation (OR, 6.15; 95% CI, 2.56-15.78) and therefore had higher rates of complications and admissions. CONCLUSIONS: MRCS is associated with greater maternal and neonatal morbidity than fewer caesarean sections. The associated maternal morbidity is largely secondary to placenta praevia and accreta, whereas higher rates of preterm delivery are most likely a response to antepartum haemorrhage.


Assuntos
Recesariana/estatística & dados numéricos , Complicações na Gravidez/cirurgia , Adulto , Índice de Massa Corporal , Feminino , Humanos , Incidência , Placenta Prévia/epidemiologia , Placenta Prévia/cirurgia , Hemorragia Pós-Parto/epidemiologia , Hemorragia Pós-Parto/cirurgia , Gravidez , Complicações na Gravidez/epidemiologia , Resultado da Gravidez , Segundo Trimestre da Gravidez , Terceiro Trimestre da Gravidez , Estudos Prospectivos , Reino Unido/epidemiologia
14.
Bull Math Biol ; 75(8): 1284-303, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23354930

RESUMO

The mechanical behavior of the actin cytoskeleton has previously been investigated using both experimental and computational techniques. However, these investigations have not elucidated the role the cytoskeleton plays in the compression resistance of cells. The present study combines experimental compression techniques with active modeling of the cell's actin cytoskeleton. A modified atomic force microscope is used to perform whole cell compression of osteoblasts. Compression tests are also performed on cells following the inhibition of the cell actin cytoskeleton using cytochalasin-D. An active bio-chemo-mechanical model is employed to predict the active remodeling of the actin cytoskeleton. The model incorporates the myosin driven contractility of stress fibers via a muscle-like constitutive law. The passive mechanical properties, in parallel with active stress fiber contractility parameters, are determined for osteoblasts. Simulations reveal that the computational framework is capable of predicting changes in cell morphology and increased resistance to cell compression due to the contractility of the actin cytoskeleton. It is demonstrated that osteoblasts are highly contractile and that significant changes to the cell and nucleus geometries occur when stress fiber contractility is removed.


Assuntos
Osteoblastos/fisiologia , Fibras de Estresse/fisiologia , Células 3T3 , Citoesqueleto de Actina/fisiologia , Animais , Fenômenos Biomecânicos , Forma Celular , Força Compressiva , Simulação por Computador , Camundongos , Microscopia de Força Atômica , Modelos Biológicos , Osteoblastos/citologia
15.
Animal ; 17(11): 101006, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37897868

RESUMO

It is common in many countries for sheep to be housed during winter from mid-gestation until lambing to protect ewes and lambs from adverse conditions and improve late gestation nutritional management. Keeping ewes indoors, however, has its own challenges as the animals may be mixed with unfamiliar conspecifics, have limited floor and feeding space, experience changes to their diet and increased handling by humans. Therefore, the objective of this study was to investigate the effect of variation in housing management (space allowance and social stability) on the behaviour and hypothalamic-pituitary-adrenal (HPA) axis responses of pregnant ewes from mid-to-late gestation (weeks 11-18 of pregnancy). Seventy-seven ewes (41 primiparous, 36 multiparous) were divided into two groups: 'Control' and 'Restricted space and mixed' (RS-Mix), where RS-Mix ewes were allocated half the amount of space (1.27 vs 2.5 m2 for RS-Mix and Control, respectively) and feedface (concentrate feeder space) allowance (36 vs 71 cm per ewe) given to the Control group and were also subjected to two social mixing events. Aggressive behaviour at the feedface and time spent standing, lying, walking, feeding and ruminating were recorded and faecal samples were collected for assessment of faecal glucocorticoid metabolite (FGM) concentrations. Higher aggression was observed in RS-Mix ewes during the first week of observation (P = 0.044), which gradually declined to the same level as Control ewes by the end of the study (P = 0.045). RS-Mix ewes were significantly less likely to be able to freely join the feedface compared to Controls (P = 0.022). No other significant treatment effects on aggressive behaviour or FGM during gestation were found. RS-Mix ewes displayed significantly higher ruminating behaviour at week 18 of gestation compared to Control ewes (P < 0.001), but no other effects were seen on general pen behaviour. However, the effect of indoor housing had a significant impact on primiparous ewes, who had lower weight gain (P = 0.015) and higher FGM concentrations (P = 0.014) compared to multiparous ewes regardless of treatment group. The data suggest that, although no sustained effects on behaviour or HPA axis responses were seen with the differences in space and feeder allowance or social stability at the levels used in this study, inexperienced (primiparous) ewes may find indoor housing more stressful; and are less able to adapt compared to multiparous ewes. These effects may influence the behaviour of the ewe at lambing time, and her offspring.


Assuntos
Sistema Hipotálamo-Hipofisário , Sistema Hipófise-Suprarrenal , Humanos , Ovinos , Animais , Gravidez , Feminino , Paridade , Dieta/veterinária , Abrigo para Animais
16.
Phys Rev Lett ; 108(26): 268302, 2012 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-23005019

RESUMO

We show that the precise orientation of a C(60) molecule which terminates the tip of a scanning probe microscope can be determined with atomic precision from submolecular contrast images of the fullerene cage. A comparison of experimental scanning tunneling microscopy data with images simulated using computationally inexpensive Hückel theory provides a robust method of identifying molecular rotation and tilt at the end of the probe microscope tip. Noncontact atomic force microscopy resolves the atoms of the C(60) cage closest to the surface for a range of molecular orientations at tip-sample separations where the molecule-substrate interaction potential is weakly attractive. Measurements of the C(60)-C(60) pair potential acquired using a fullerene-terminated tip are in excellent agreement with theoretical predictions based on a pairwise summation of the van der Waals interactions between C atoms in each cage, i.e., the Girifalco potential [L. Girifalco, J. Phys. Chem. 95, 5370 (1991)].

17.
Phys Chem Chem Phys ; 14(47): 16250-7, 2012 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-23111800

RESUMO

Complex interplay between topography and dissipation signals in Non-Contact Atomic Force Microscopy (NC-AFM) is studied by a combination of state-of-the-art theory and experiment applied to the Si(001) surface prone to instabilities. Considering a wide range of tip-sample separations down to the near-contact regime and several tip models, both stiff and more flexible, a sophisticated architecture of hysteresis loops in the simulated tip force-distance curves is revealed. At small tip-surface distances the dissipation was found to be comprised of two related contributions due to both the surface and tip. These are accompanied by the corresponding surface and tip distortion approach-retraction dynamics. Qualitative conclusions drawn from the theoretical simulations such as large dissipation signals (>1.0 eV) and a step-like dissipation dependent on the tip-surface distance are broadly supported by the experimental observations. In view of the obtained results we also discuss the reproducibility of NC-AFM imaging.

18.
Exp Physiol ; 95(1): 184-93, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19734174

RESUMO

Women are generally recognized to be less orthostatically tolerant than men. We hypothesized that during head-up tilt (HUT), women would demonstrate less splanchnic vasoconstriction, leading to splanchnic pooling, lower blood pressure and lower orthostatic tolerance. Mean arterial blood pressure (MAP), heart rate (HR), cardiac output ((.)Q(c), assessed by C2H2 rebreathing), stroke volume, splanchnic blood flow (SpBF, assessed by Indocyanine Green clearance) and vascular conductance (systemic, SVC = (.)Qc/MAP; splanchnic, SpVC = SpBF/MAP; non-splanchnic, non-SpVC = SVC - SpVC) were measured during supine baseline conditions, 70 deg HUT and recovery in 14 healthy women (23 +/- 6 years old; mean +/- S.D.) and 16 men (23 +/- 5 years old). The proportion of sexes surviving 45 min of HUT trended towards significance (chi(2) = 2.92, P = 0.09). The MAP was lower in women than in men (supine, 77 +/- 5 versus 86 +/- 9 mmHg, P < 0.01; tilt, 72 +/- 8 versus 83 +/- 10 mmHg, P < 0.01), while HR and cardiac index ( /body surface area) were not different between the sexes (heart rate supine, 66 +/- 6 versus 64 +/- 8 beats min(-1); heart rate tilt, 96 +/- 13 versus 94 +/- 10 beats min(-1); cardiac index supine, 3.8 +/- 0.9 versus 3.7 +/- 0.7 l min(-1) m(2); cardiac index tilt, 2.7 +/- 0.8 versus 2.3 +/- 0.5 l min(-1) m(2)). The SpBF and SpVC were lower in women at rest but not during tilt (SpBF supine, 1174 +/- 243 versus 1670 +/- 391 ml min(-1), P < 0.01; SpVC supine, 14.83 +/- 3.61 versus 19.59 +/- 4.95 ml min(-1) mmHg(1), P < 0.01; SpBF tilt, 884 +/- 300 versus 1094 +/- 271 ml min(-1); SpVC tilt, 13.14 +/- 4.28 versus 14.82 +/- 4.16 ml min(-1) mmHg(-1)). However, in the women the SpVC did not decrease from baseline to tilt (SpVC, in women, 1.70 +/- 3.19 ml min(-1) mmHg(-1), n.s.; in men, 4.81 +/- 3.44 ml min(-1) mmHg(-1), P < 0.01), suggesting a blunted vasoconstrictor response. In conclusion, women tended to have lower tilt-table tolerance associated with a smaller splanchnic vasoconstrictor reserve than men.


Assuntos
Caracteres Sexuais , Teste da Mesa Inclinada/métodos , Vasoconstrição/fisiologia , Adolescente , Adulto , Pressão Sanguínea/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Circulação Esplâncnica/fisiologia , Teste da Mesa Inclinada/instrumentação , Adulto Jovem
19.
Emerg Med J ; 27(1): 74-5, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20029019

RESUMO

Pomegranate juice is growing in popularity in the UK. We report a potential interaction between pomegranate juice and warfarin. Laboratory studies have shown that pomegranate juice inhibits cytochrome P450 enzymes involved in warfarin metabolism. As with previous reports of interactions between food and warfarin, this case does not definitively prove the association between pomegranate juice consumption and increased warfarin bioactivity but highlights the importance of taking a complete drug, food and juice history when assessing patients with unstable anticoagulation.


Assuntos
Anticoagulantes/uso terapêutico , Interações Alimento-Droga , Frutas/efeitos adversos , Hematoma/etiologia , Lythraceae/efeitos adversos , Varfarina/uso terapêutico , Feminino , Hematoma/diagnóstico , Humanos , Coeficiente Internacional Normatizado , Pessoa de Meia-Idade
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