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1.
medRxiv ; 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38559227

RESUMEN

Type 2 diabetes mellitus (T2DM) may be a long-term sequela of infection with Mycobacterium tuberculosis (M.tb) by mechanisms that remain to be fully explained. We evaluated association between M.tb sensitization and T2DM among U.S adults and, via formal mediation analysis, the extent to which this association is mediated by insulin resistance and/or ß-cell failure. These evaluations accounted for demographic, socio-economic, behavioral and clinical characteristics. T2DM was assessed by fasting plasma glucose, 2-hour oral glucose tolerance testing and HbA1c; homoeostasis model assessment 2 (HOMA2) was used to estimate ß-cell dysfunction (HOMA2-B) and insulin resistance (HOMA2-IR); while M.tb sensitization status was ascertained by tuberculin skin testing (TST). Exposure to M.tb was associated with increased risk for T2DM, likely driven by an increase in insulin resistance. Definitive prospective studies examining incident T2DM following tuberculosis are warranted. Research in Context: What is already known about this subject?: Accumulating evidence suggests that pre-diabetes and new-onset type 2 diabetes mellitus (T2DM) may be a long-term complication of exposure to Mycobacterium tuberculosis ( M.tb ) via mechanisms that remain to be unraveled What is the key question?: To what extent do insulin resistance and ß-cell failure mediate the association between M.tb sensitization with T2DM among US adults? What are the new findings?: M.tb sensitization is characterized by distinct glucose metabolic disturbances manifesting as increased risk of T2DM and isolated impaired fasting glucose (IFG) Insulin resistance, and not ß-cell impairment, likely independently mediate the observed diabetogenic effects of M.tb sensitization How might this impact on clinical and/or public health practice in the foreseeable future?: If corroborated by prospective studies, both TB programs and individual clinical care must incorporate monitoring of serum glucose and long-term metabolic outcomesThis will be particularly urgent in sub-Saharan Africa and South-East Asia where scarce health resources coincide with overlapping endemic TB and epidemic T2DM.

2.
J Dairy Sci ; 107(6): 3543-3557, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38211692

RESUMEN

The increasing cost of milk production, in association with tighter manure N application regulations and challenges associated with ammonia emissions in many countries, has increased interest in feeding lower crude protein (CP) diets based on legume silages. Most studies have focused on alfalfa silage, and little information is available on low-CP diets based on red clover silage. Our objectives were to examine the effects of dietary CP content and supplementing a low-CP diet with dietary starch or rumen-protected Met (RPMet) on the performance, metabolism, and nitrogen use efficiency (NUE; milk N output/N intake) in dairy cows fed a red clover and grass silage-based diet. A total of 56 Holstein-Friesian dairy cows were blocked and randomly allocated to 1 of 4 diets over a 14-wk feeding period. Diets were based on red clover and grass silages at a ratio of 50:50 on a dry matter (DM) basis and were fed as a total mixed ration, with a 53:47 ratio of forage to concentrate (DM basis). The diets were formulated to supply a similar metabolizable protein (MP) content, and had a CP concentration of either 175 g/kg DM (control [CON]) or 150 g/kg DM (low-protein [LP]), or LP supplemented with either additional barley as a source of starch (LPSt; +64 g/kg DM) or RPMet (LPM; +0.3 g/100 g MP). At the end of the 14-wk feeding period, 20 cows (5 per treatment) continued to be fed the same diets for a further 6 d, and total urine output and fecal samples were collected. We observed that dietary treatment did not affect DM intake, with a mean of 21.5 kg/d; however, we also observed an interaction between diet and week with intake being highest in cows fed LPSt in wk 4 and CON in wk 9 and 14. Mean milk yield, 4% fat-corrected milk, and energy-corrected milk were not altered by treatment. Similarly, we found no effect of dietary treatment on milk fat, protein, or lactose content. In contrast, milk and plasma urea concentrations were highest in cows fed CON. The concentration of blood plasma ß-hydroxybutyrate was highest in cows receiving LPM and lowest in LPSt. Apparent NUE was 28.6% in cows fed CON and was higher in cows fed any of the low-protein diets (LP, LPSt, or LPM), with a mean value of 34.2%. The sum of milk fatty acids with a chain length below C16:0 was also highest in cows fed CON. We observed that dietary treatment did not affect the apparent whole-tract nutrient digestibility of organic matter, N, neutral detergent fiber, and acid detergent fiber, with mean values of 0.785, 0.659, 0.660, and 0.651 kg/kg respectively, but urinary N excretion was approximately 60 g/d lower in cows fed the low-CP diets compared with CON. We conclude that reducing the CP content of red clover and grass silage-based diets from 175 to 150 g/kg DM while maintaining MP supply did not affect performance, but reduced the urinary N excretion and improved NUE, and that supplementing additional starch or RPMet had little further effect.


Asunto(s)
Dieta , Proteínas en la Dieta , Suplementos Dietéticos , Lactancia , Metionina , Leche , Nitrógeno , Rumen , Ensilaje , Almidón , Animales , Bovinos , Femenino , Nitrógeno/metabolismo , Metionina/metabolismo , Dieta/veterinaria , Almidón/metabolismo , Rumen/metabolismo , Leche/química , Leche/metabolismo , Proteínas en la Dieta/metabolismo , Alimentación Animal , Trifolium/metabolismo , Poaceae/metabolismo
3.
J Theor Biol ; 581: 111745, 2024 03 21.
Artículo en Inglés | MEDLINE | ID: mdl-38272110

RESUMEN

Migrating cells traverse a range of topographic configurations presented by the native extracellular environment to conduct their physiologic functions. It is well documented cells can modulate their behaviour in response to different topographic features, finding promising applications in biomaterial and bioimplant design. It is useful, in these areas of research, to be able to predict which topographic arrangements could be used to promote certain patterns of migration prior to laboratory experimentation. Despite a profusion of study and interest shown in these fields by experimentalists, the related modelling literature is as yet relatively sparse and tend to focus more on either cell-matrix interaction or morphological responses of cells. We propose a mathematical model for individual cell migration based on an Ornstein-Uhlenbeck process, and set out to see if the model can be used to predict migration patterns on 2-d isotropic and anisotropic topographies, whose characteristics can be broadly described as either uniform flat, uniform linear with variable ridge density or non-uniform disordered with variable feature density. Results suggest the model is capable of producing realistic patterns of migration for flat and linear topographic patterns, with calibrated output closely approximating NIH3T3 fibroblast migration behaviour derived from an experimental dataset, in which migration linearity increased with ridge density and average speed was highest at intermediate ridge densities. Exploratory results for non-uniform disordered topographies suggest cell migration patterns may adopt disorderedness present in the topography and that 'distortion' introduced to linear topographic patterns may not impede linear guidance of migration, given its magnitude is bounded within certain limits. We conclude that an Ornstein-Uhlenbeck based model for topographically influenced migration may be useful to predict patterns of migration behaviour for certain isotropic (flat) and anisotropic (linear) topographies in the NIH3T3 fibroblast cell line, but additional investigation is required to predict with confidence migration patterns for non-uniform disordered topographic arrangements.


Asunto(s)
Células 3T3 NIH , Ratones , Animales , Movimiento Celular
4.
Epidemiol Psychiatr Sci ; 32: e65, 2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-37964589

RESUMEN

AIMS: Three factors converge to underscore the heightened importance of evaluating the potential health/well-being effects of friendships in older adulthood. First, policymakers, scientists, and the public alike are recognizing the importance of social relationships for health/well-being and creating national policies to promote social connection. Second, many populations are rapidly aging throughout the world. Third, we currently face what some call a 'friendship recession'. Although, growing research documents associations between friendship with better health and well-being, friendship can also have a 'dark side' and can potentially promote negative outcomes. To better capture friendship's potential heterogeneous effects, we took an outcome-wide analytic approach. METHODS: We analysed data from 12,998 participants in the Health and Retirement Study (HRS) - a prospective and nationally representative cohort of U.S. adults aged >50, and, evaluated if increases in friendship strength (between t0; 2006/2008 and t1; 2010/2012) were associated with better health/well-being across 35 outcomes (in t2; 2014/2016). To assess friendship strength, we leveraged all available friendship items in HRS and created a composite 'friendship score' that assessed the following three domains: (1) friendship network size, (2) friendship network contact frequency and (3) friendship network quality. RESULTS: Stronger friendships were associated with better outcomes on some indicators of physical health (e.g. reduced risk of mortality), health behaviours (e.g. increased physical activity) and nearly all psychosocial indicators (e.g. higher positive affect and mastery, as well as lower negative affect and risk of depression). Friendship was also associated with increased likelihood of smoking and heavy drinking (although the latter association with heavy drinking did not reach conventional levels of statistical significance). CONCLUSIONS: Our findings indicate that stronger friendships can have a dual impact on health and well-being. While stronger friendships appear to mainly promote a range of health and well-being outcomes, stronger friendships might also promote negative outcomes. Additional research is needed, and any future friendship interventions and policies that aim to enhance outcomes should focus on how to amplify positive outcomes while mitigating harmful ones.


Asunto(s)
Amigos , Relaciones Interpersonales , Humanos , Anciano , Amigos/psicología , Estudios Prospectivos , Envejecimiento
5.
J Dairy Sci ; 106(3): 1773-1789, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36710192

RESUMEN

Reducing the dietary crude protein (CP) concentration can decrease the financial cost and lower the environmental impact of milk production. Two studies were conducted to examine the effects of reducing the dietary CP concentration on animal performance, nutrient digestibility, milk fatty acid (FA) profile, and nitrogen use efficiency (NUE; milk N/N intake) in dairy cows fed legume silage-based diets. Thirty-six multiparous Holstein-Friesian dairy cows that were 76 ± 14 (mean ± SD) days in milk and 698 ± 54 kg body weight were used in a 3 × 3 Latin square design in each of 2 studies, with 3 periods of 28 d. In study 1, cows were fed diets based on a 50:50 ratio of red clover to grass silage [dry matter (DM) basis] containing 1 of 3 dietary CP concentrations: high (H) = 175 g of CP/kg of DM; medium (M) = 165 g of CP/kg of DM; or low (L) = 150 g of CP/kg of DM. In study 2, cows were fed 175 g of CP/kg of DM with a 50:50 ratio of alfalfa to corn silage (H50) or 1 of 2 diets containing 150 g of CP/kg of DM with either a 50:50 (L50) or a 60:40 (L60) ratio of alfalfa to corn silage. Cows in both studies were fed a total mixed ration with a forage-to-concentrate ratio of 52:48 (DM basis). All diets were formulated to meet the MP requirements, except L (95% of MP requirements). In study 1, cows fed L ate 1.6 kg of DM/d less than those fed H or M, but milk yield was similar across treatments. Mean milk protein, fat, and lactose concentrations were not affected by diet. However, the apparent total-tract nutrient digestibility was decreased in cows fed L. The NUE was 5.7 percentage units higher in cows fed L than H. Feeding L also decreased milk and plasma urea concentrations by 4.4 mg/dL and 0.78 mmol/L, respectively. We found no effect of dietary treatment on the milk saturated or monounsaturated FA proportion, but the proportion of polyunsaturated FA was increased, and milk odd- and branched-chain FA decreased in cows fed L compared with H. In study 2, DM intake was 2 kg/d lower in cows receiving L50 than H50. Increasing the alfalfa content and feeding a low-CP diet (L60) did not alter DMI but decreased milk yield and milk protein concentration by 2 kg/d and 0.6 g/kg, respectively, compared with H50. Likewise, milk protein and lactose yield were decreased by 0.08 kg/d in cows receiving L60 versus H50. Diet had no effect on apparent nutrient digestibility. Feeding the low-CP diets compared with H50 increased the apparent NUE by approximately 5 percentage units and decreased milk and plasma urea concentrations by 7.2 mg/dL and 1.43 mmol/L, respectively. Dietary treatment did not alter milk FA profile except cis-9,trans-11 conjugated linoleic acid, which was higher in milk from cows receiving L60 compared with H50. We concluded that reducing CP concentration to around 150 g/kg of DM in red clover and grass or alfalfa and corn silage-based diets increases the apparent NUE and has little effect on nutrient digestibility or milk performance in dairy cows.


Asunto(s)
Ensilaje , Trifolium , Femenino , Bovinos , Animales , Ensilaje/análisis , Poaceae/metabolismo , Zea mays/metabolismo , Medicago sativa/metabolismo , Trifolium/metabolismo , Lactancia , Lactosa/metabolismo , Nitrógeno/metabolismo , Dieta/veterinaria , Proteínas de la Leche/metabolismo , Ácidos Grasos/metabolismo , Urea/metabolismo
6.
Clin Oncol (R Coll Radiol) ; 35(2): e199-e205, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36509615

RESUMEN

AIMS: Uterine serous carcinoma (USC) is an aggressive subtype of endometrial cancer with high rates of relapse and death. As adjuvant therapy might be beneficial in early-stage disease, the impact of standard complete surgical staging is questioned. Therefore, we wanted to explore the optimal treatment strategy for women diagnosed with USC. MATERIALS AND METHODS: A retrospective multicentre study of women diagnosed with primary USC in the UK and the Netherlands. Treatment strategy in relation to overall survival and progression-free survival was recorded and evaluated with Kaplan-Meier and Cox regression analysis. Furthermore, primary surgical staging and/or adjuvant treatment in relation to patterns of recurrence were evaluated. RESULTS: In total, 272 women with a median age of 70 years were included. Most patients presented with International Federation of Gynecology and Obstetrics (FIGO) stage I disease (44%). Overall, 48% of patients developed recurrent disease, most (58%) with a distant component. Women treated with chemotherapy showed significantly better overall survival (hazard ratio 0.50, 95% confidence interval 0.31-0.81; P = 0.005) and progression-free survival (hazard ratio 0.48, 95% confidence interval 0.28-0.80; P = 0.04) in multivariable analysis. Furthermore, even in surgically staged women with FIGO stage IA disease, a high recurrence rate of 42% was seen. CONCLUSION: Women with USC who received adjuvant chemotherapy showed better survival rates compared with those who received other or no adjuvant treatment. The benefit of adjuvant chemotherapy was observed across all tumour stages, including surgically staged FIGO stage IA. These data question the role of surgical staging in the absence of macroscopic disease in USC.


Asunto(s)
Cistadenocarcinoma Seroso , Neoplasias Endometriales , Neoplasias Uterinas , Humanos , Femenino , Anciano , Estadificación de Neoplasias , Terapia Combinada , Cistadenocarcinoma Seroso/cirugía , Quimioterapia Adyuvante , Supervivencia sin Enfermedad , Estudios Retrospectivos , Neoplasias Uterinas/cirugía , Neoplasias Uterinas/tratamiento farmacológico , Neoplasias Endometriales/patología
7.
S. Afr. j. sports med. (Online) ; 35(2): 1-7, 2023. figures, tables
Artículo en Inglés | AIM (África) | ID: biblio-1531593

RESUMEN

Background: By using complementary therapies, such as exercise rehabilitation during and after cancer treatment, breast cancer patients and survivors can improve their quality of life and overall health while also negating the deleterious effects of breast cancer and its treatment. Objectives: The aim of this study was to determine the physical activity levels of female breast cancer patients and survivors in Ekurhuleni, South Africa. Methods: The International Global Physical Activity Questionnaire (2002) determined participants' physical activity levels during work, travel and leisure. The questionnaire was disseminated to medical facilities in hard copy format and online via the Google Forms platform. Statistics were computed using the Statistical Package for Social Science (SPSS) with the level of significance set at 95% (p < 0.05). Results: One hundred female breast cancer patients and survivors with a mean age of 55 years from Ekurhuleni, South Africa participated in this study. The findings reflected that most participants (59%) were meeting the American College of Sports Medicine's physical activity guidelines when considering activity done during work, travel and leisure. No significant difference was seen in physical activity participation between breast cancer patients and breast cancer survivors, or those attending private and public facilities. Conclusion: For the breast cancer patient, physical activity and exercise may be a promising and effective adjuvant treatment both during and after anticancer therapies, improving quality of life, playing a role in increasing treatment tolerance, mitigating a range of symptoms and side effects brought on by cancer diagnosis and treatments and enhancing outcomes


Asunto(s)
Humanos , Femenino
8.
S Afr J Sports Med ; 35(1): v35i1a16001, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38249762

RESUMEN

Background: By using complementary therapies, such as exercise rehabilitation during and after cancer treatment, breast cancer patients and survivors can improve their quality of life and overall health while also negating the deleterious effects of breast cancer and its treatment. Objectives: The aim of this study was to determine the physical activity levels of female breast cancer patients and survivors in Ekurhuleni, South Africa. Methods: The International Global Physical Activity Questionnaire (2002) determined participants' physical activity levels during work, travel and leisure. The questionnaire was disseminated to medical facilities in hard copy format and online via the Google Forms platform. Statistics were computed using the Statistical Package for Social Science (SPSS) with the level of significance set at 95% (p < 0.05). Results: One hundred female breast cancer patients and survivors with a mean age of 55 years from Ekurhuleni, South Africa participated in this study. The findings reflected that most participants (59%) were meeting the American College of Sports Medicine's physical activity guidelines when considering activity done during work, travel and leisure. No significant difference was seen in physical activity participation between breast cancer patients and breast cancer survivors, or those attending private and public facilities. Conclusion: For the breast cancer patient, physical activity and exercise may be a promising and effective adjuvant treatment both during and after anticancer therapies, improving quality of life, playing a role in increasing treatment tolerance, mitigating a range of symptoms and side effects brought on by cancer diagnosis and treatments and enhancing outcomes.

9.
medRxiv ; 2023 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-38168355

RESUMEN

Mortality from HIV-associated tuberculosis (HIV-TB) is high, particularly among hospitalised patients. In 433 people living with HIV admitted to hospital with symptoms of TB, we investigated plasma matrix metalloproteinases (MMP) and matrix-derived biomarkers in relation to TB diagnosis, mortality and Mycobacterium tuberculosis (Mtb) blood stream infection (BSI). Compared to other diagnoses, MMP-8 was elevated in confirmed TB and in Mtb-BSI, positively correlating with extracellular matrix breakdown products. Baseline MMP-3, -7, -8, -10 and procollagen III N-terminal propeptide (PIIINP) associated with Mtb-BSI and 12-week mortality. These findings implicate MMP dysregulation in pathophysiology of advanced HIV-TB and support MMP inhibition as a host-directed therapeutic strategy for HIV-TB.

10.
Infect Dis Ther ; 11(4): 1327-1341, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35767219

RESUMEN

Tuberculous meningitis (TBM) is the most severe and disabling form of tuberculosis (TB), with at least 100,000 cases per year and a mortality rate of up to 50% in individuals co-infected with human immunodeficiency virus type 1 (HIV-1). To evaluate the efficacy and safety of an intensified anti-tubercular regimen and an anti-inflammatory treatment, the INTENSE-TBM project includes a phase III randomised clinical trial (TBM-RCT) in four countries in sub-Saharan Africa (SSA). Within this framework, we designed a comprehensive capacity-building work package ensuring all centres had, or would acquire, the ability to conduct the TBM-RCT and developing a network of skilled researchers, clinical centres and microbiology laboratories. Here, we describe these activities, identify strengths/challenges and share tools adaptable to other projects, particularly in low- and lower-middle income countries with heterogeneous settings and during the coronavirus disease 2019 (COVID-19) pandemic. Despite major challenges, TBM-RCT initiation was achieved in all sites, promoting enhanced local healthcare systems and encouraging further clinical research in SSA. In terms of certified trainings, the achievement levels were 95% (124/131) for good clinical practice, 91% (39/43) for good clinical laboratory practice and 91% (48/53) for infection prevention and control. Platform-based research, developed as part of capacity-building activities for specific projects, may be a valuable tool in fighting future infectious diseases and in developing high-level research in Africa.


The INTENSE-TBM project aimed to design a comprehensive work-package on capacity building, ensuring all centres would acquire the ability to conduct a phase III randomised clinical trial on TBM in sub-Saharan Africa, to reduce tuberculous meningitis mortality and morbidity in patients with/without HIV-1 co-infection. Therefore, the INTENSE-TBM project is an example of how an international clinical research consortium can provide opportunities to enhance local capacity building and promote centres without previous experience in clinical research. This article provides practical approaches for implementing effective capacity-building programmes. We highlight how to overcome limitations imposed by the COVID-19 pandemic to successfully complete clinics, laboratory set-ups and personnel training, so as to optimise resources and empower African institutions on a local level. At the same time, our experience shows how capacity-building programmes can deliver long-lasting impact that extends beyond the original aims of the project (e.g. HIV and TB), and support local health systems in fighting other infectious disease (e.g. COVID-19). Research projects in low- and lower-middle income countries with heterogeneous settings could stand to benefit the most.

11.
S Afr J Sports Med ; 34(1): v34i1a11555, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36815925

RESUMEN

Background: Little epidemiological research on rheumatoid arthritis (RA) has been done in Africa, suggesting that it is an uncommon illness. In rural South Africa, RA has an overall prevalence of 0.07% and a prevalence of 2.5% in urban areas; therefore, it is not as uncommon as perceived by the lack of research. Patient-centred programmes to improve physical function have been lacking and, as a result, the prior assumption was that physical activity should be avoided. Objectives: To determine pain and physical activity levels among RA patients between the ages of 18 to 50 years in South Africa. Methods: A combination of two questionnaires were used, namely, the Global Physical Activity Questionnaire (2002) and the Pain Outcomes Questionnaire (2003). The collated questionnaires were distributed by rheumatologists and on social media platforms to RA patients between the ages of 18 to 50 years old living in South Africa. This study had a sample size of 105 participants, with participation occurring through the online Google forms platform. Results: One hundred and five participants with RA were recruited with an average age of 38±9 years. Most of the participants were females (93.3%). Seventy-two percent of the sample was classified as physically active, where work, leisure and travel activities were considered. No significant correlation between pain and physical activity was evident (r=0.10; p=0.311). Results showed significant correlations between pain and personal grooming (r=0.30; p=0.002), pain and ambulation (r=0.60; p=0.000), and pain and stair climbing (r=0.60; p=0.000). Conclusion: Physical activity has proven to have multiple benefits for those suffering with RA. In this South African sample of RA patients, the majority were classified as physically active, and pain did not affect the activity levels of the involved participants. This study opens further research questions regarding RA prevalence in South Africa, and the type and intensity of physical activity that would be beneficial for RA.

12.
J Public Health (Oxf) ; 43(4): e645-e655, 2021 12 10.
Artículo en Inglés | MEDLINE | ID: mdl-33300580

RESUMEN

BACKGROUND: Ill health associated with household air pollution (HAP) is increasingly recognized as a public health problem in sub-Saharan Africa. To date, attempts to reduce HAP have focussed on smoke from cooking fires and have ignored traditional cultural practices which generate purposely produced smoke (PPS). This study aimed to investigate PPS prevalence, reasons for use and safety perceptions. METHODS: The study was conducted in Wollo, Ethiopia, and used a mixed methods approach of quantitative surveys (analysed descriptively) and qualitative interviews with householders and healthcare workers (analysed thematically). RESULTS: PPS use was reported by 99% of survey respondents and it was considered a fundamental part of life. Although reasons for use included housekeeping, culture/religion and well-being, coffee ceremony was most commonly cited (44% of respondents). Both householders and healthcare workers appeared to assume PPS is safe, except for people with certain underlying conditions. Healthcare workers felt the lack of evidence of harm from PPS meant there was no justification for intervention. CONCLUSION: This study, the first in-depth study of PPS, has shown its use to be widespread, with many perceived benefits and thus a very important part of local culture in this sample Ethiopian community. Consequently, any public health interventions aimed at reducing HAP in this setting need to consider PPS.


Asunto(s)
Contaminación del Aire Interior , Contaminación del Aire , Contaminación del Aire/efectos adversos , Contaminación del Aire Interior/análisis , Culinaria , Etiopía , Humanos , Humo
13.
Proc Math Phys Eng Sci ; 475(2224): 20180854, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31105458

RESUMEN

The study of palaeoclimates relies on information sampled in natural archives such as deep sea cores. Scientific investigations often use such information in multi-stage analyses, typically with an age model being fitted to a core to convert depths into ages at stage one. These age estimates are then used as inputs to develop, calibrate or select climate models in a second stage of analysis. Here, we show that such multi-stage approaches can lead to misleading conclusions, and develop a joint inferential approach for climate reconstruction, model calibration and age estimation. As an illustration, we investigate the glacial-interglacial cycle, fitting both an age model and dynamical climate model to two benthic sediment cores spanning the past 780 kyr. To show the danger of a multi-stage analysis, we sample ages from the posterior distribution, then perform model selection conditional on the sampled age estimates, mimicking standard practice. Doing so repeatedly for different samples leads to model selection conclusions that are substantially different from each other, and from the joint inferential analysis. We conclude that multi-stage analyses are insufficient when dealing with uncertainty, and that to draw sound conclusions the full joint inferential analysis should be performed.

14.
Animal ; 13(3): 524-532, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29983121

RESUMEN

The particle size of the forage has been proposed as a key factor to ensure a healthy rumen function and maintain dairy cow performance, but little work has been conducted on ryegrass silage (GS). To determine the effect of chop length of GS and GS:maize silage (MS) ratio on the performance, reticular pH, metabolism and eating behaviour of dairy cows, 16 multiparous Holstein-Friesian cows were used in a 4×4 Latin square design with four periods each of 28-days duration. Ryegrass was harvested and ensiled at two mean chop lengths (short and long) and included at two ratios of GS:MS (100:0 or 40:60 dry matter (DM) basis). The forages were fed in mixed rations to produce four isonitrogenous and isoenergetic diets: long chop GS, short chop GS, long chop GS and MS and short chop GS and MS. The DM intake (DMI) was 3.2 kg/day higher (P<0.001) when cows were fed the MS than the GS-based diets. The short chop length GS also resulted in a 0.9 kg/day DM higher (P<0.05) DMI compared with the long chop length. When fed the GS:MS-based diets, cows produced 2.4 kg/day more (P<0.001) milk than when fed diets containing GS only. There was an interaction (P<0.05) between chop length and forage ratio for milk yield, with a short chop length GS increasing yield in cows fed GS but not MS-based diets. An interaction for DM and organic matter digestibility was also observed (P<0.05), where a short chop length GS increased digestibility in cows when fed the GS-based diets but had little effect when fed the MS-based diet. When fed the MS-based diets, cows spent longer at reticular pH levels below pH 6.2 and pH 6.5 (P<0.01), but chop length had little effect. Cows when fed the MS-based diets had a higher (P<0.05) milk fat concentration of C18 : 2n-6 and total polyunsaturated fatty acids compared with when fed the GS only diets. In conclusion, GS chop length had little effect on reticular pH, but a longer chop length reduced DMI and milk yield but had little effect on milk fat yield. Including MS reduced reticular pH, but increased DMI and milk performance irrespective of the GS chop length.


Asunto(s)
Bovinos/fisiología , Tamaño de la Partícula , Poaceae , Rumen/fisiología , Ensilaje , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Dieta/veterinaria , Ácidos Grasos Insaturados/metabolismo , Femenino , Concentración de Iones de Hidrógeno , Lactancia , Leche/metabolismo
15.
Int J Ment Health Addict ; 16(5): 1125-1139, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30416401

RESUMEN

Risky paternal alcohol use is associated with maternal alcohol use during pregnancy, poor fetal and infant outcomes, domestic violence and depression. This study developed 30 SMS text messages about alcohol for fathers who drink at risky levels. The text messages were developed using two motivational styles: messages presented in a second person voice and the same messages presented in a child's voice. Fifty-one fathers were recruited through social media to complete an online survey rating the SMS text messages for message importance and likelihood of seeking further information and measuring risky alcohol use and psychosocial distress. Seventeen participants then participated in a semi-structured qualitative interview. Fathers rated the text messages presented in the child's voice as more important than messages presented in the second person. Qualitative data supported survey results that motivational SMS text messages could provide an acceptable way to raise awareness of risky alcohol consumption for future fathers.

16.
J Theor Biol ; 436: 39-50, 2018 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-28970093

RESUMEN

Immunotherapies exploit the immune system to target and kill cancer cells, while sparing healthy tissue. Antibody therapies, an important class of immunotherapies, involve the binding to specific antigens on the surface of the tumour cells of antibodies that activate natural killer (NK) cells to kill the tumour cells. Preclinical assessment of molecules that may cause antibody-dependent cellular cytotoxicity (ADCC) involves co-culturing cancer cells, NK cells and antibody in vitro for several hours and measuring subsequent levels of tumour cell lysis. Here we develop a mathematical model of such an in vitro ADCC assay, formulated as a system of time-dependent ordinary differential equations and in which NK cells kill cancer cells at a rate which depends on the amount of antibody bound to each cancer cell. Numerical simulations generated using experimentally-based parameter estimates reveal that the system evolves on two timescales: a fast timescale on which antibodies bind to receptors on the surface of the tumour cells, and NK cells form complexes with the cancer cells, and a longer time-scale on which the NK cells kill the cancer cells. We construct approximate model solutions on each timescale, and show that they are in good agreement with numerical simulations of the full system. Our results show how the processes involved in ADCC change as the initial concentration of antibody and NK-cancer cell ratio are varied. We use these results to explain what information about the tumour cell kill rate can be extracted from the cytotoxicity assays.


Asunto(s)
Citotoxicidad Celular Dependiente de Anticuerpos , Modelos Inmunológicos , Línea Celular Tumoral , Humanos , Análisis Numérico Asistido por Computador
17.
Phys Rev Lett ; 119(24): 242701, 2017 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-29286739

RESUMEN

We have performed a direct measurement of the ^{19}Ne(p,γ)^{20}Na reaction in inverse kinematics using a beam of radioactive ^{19}Ne. The key astrophysical resonance in the ^{19}Ne+p system has been definitely measured for the first time at E_{c.m.}=456_{-2}^{+5} keV with an associated strength of 17_{-5}^{+7} meV. The present results are in agreement with resonance strength upper limits set by previous direct measurements, as well as resonance energies inferred from precision (^{3}He, t) charge exchange reactions. However, both the energy and strength of the 456 keV resonance disagree with a recent indirect study of the ^{19}Ne(d, n)^{20}Na reaction. In particular, the new ^{19}Ne(p,γ)^{20}Na reaction rate is found to be factors of ∼8 and ∼5 lower than the most recent evaluation over the temperature range of oxygen-neon novae and astrophysical x-ray bursts, respectively. Nevertheless, we find that the ^{19}Ne(p,γ)^{20}Na reaction is likely to proceed fast enough to significantly reduce the flux of ^{19}F in nova ejecta and does not create a bottleneck in the breakout from the hot CNO cycles into the rp process.

18.
Am J Transplant ; 17(8): 2178-2185, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28489305

RESUMEN

Since the first attempt of pig-to-primate liver xenotransplantation (LXT) in 1968, survival has been limited. We evaluated a model utilizing α-1,3-galactosyltransferase knockout donors, continuous posttransplant infusion of human prothrombin concentrate complex, and immunosuppression including anti-thymocyte globulin, FK-506, methylprednisone, and costimulation blockade (belatacept, n = 3 or anti-CD40 mAb, n = 1) to extend survival. Baboon 1 remained well until postoperative day (POD) 25, when euthanasia was required because of cholestasis and plantar ulcers. Baboon 2 was euthanized following a seizure on POD 5, despite normal liver function tests (LFTs) and no apparent pathology. Baboon 3 demonstrated initial stable liver function but was euthanized on POD 8 because of worsening LFTs. Pathology revealed C4d positivity, extensive hemorrhagic necrosis, and a focal cytomegalovirus inclusion. Baboon 4 was clinically well with stable LFTs until POD29, when euthanasia was again necessitated by plantar ulcerations and rising LFTs. Final pathology was C4d negative and without evidence of rejection, inflammation, or thrombotic microangiopathy. Thus, nearly 1-mo rejection-free survival has been achieved following LXT in two of four consecutive recipients, demonstrating that the porcine liver can support life in primates for several weeks and has encouraging potential for clinical application as a bridge to allotransplantation for patients with acute-on-chronic or fulminant hepatic failure.


Asunto(s)
Factores de Coagulación Sanguínea/metabolismo , Supervivencia de Injerto/efectos de los fármacos , Inmunosupresores/farmacología , Trasplante de Hígado/mortalidad , Trasplante Heterólogo , Animales , Animales Modificados Genéticamente , Supervivencia de Injerto/inmunología , Papio , Tasa de Supervivencia , Porcinos
19.
Br Dent J ; 222(10): 778-781, 2017 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-28546627

RESUMEN

Aim To explore the value of DGA data as an indicator of the impact and inequalities associated with child dental decay (caries) in Southampton.Design Data from the local DGA provider in Southampton was used to investigate trends in child (17 years and under) DGAs between 2006/7 and 2014/15. Retrospective analysis of anonymised child-level 2013/14 and 2014/15 data from the same service was carried out to identify any inequalities with respect to deprivation, impact on school attendance and cost to the health economy.Results Around 400-500 Southampton children needed a DGA annually within this period. There were year-on-year variations, but no upward or downward trend. The DGA rate was 2.5 to three times higher in the most deprived quintile compared to the least. This translates to an equivalent gap in school absences, which could impact on educational achievement. The cost of these procedures in 2014/15 was around £210,000.Conclusions DGA data have value in highlighting the impact and inequalities associated with dental decay on children and the wider economy. Nationally, they could be used for benchmarking. Locally, these data could be used to target and evaluate health improvement programmes as well as to highlight DGA service changes that would disproportionately affect children from more deprived backgrounds.


Asunto(s)
Anestesia Dental/estadística & datos numéricos , Anestesia General/estadística & datos numéricos , Caries Dental/epidemiología , Extracción Dental/estadística & datos numéricos , Anestesia Dental/economía , Anestesia General/economía , Preescolar , Caries Dental/cirugía , Inglaterra/epidemiología , Costos de la Atención en Salud , Disparidades en el Estado de Salud , Humanos , Lactante , Recién Nacido , Pobreza/estadística & datos numéricos , Estudios Retrospectivos , Extracción Dental/economía , Extracción Dental/métodos
20.
Tuberculosis (Edinb) ; 98: 62-76, 2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-27156620

RESUMEN

Infection with HIV-1 greatly increases the risk of active tuberculosis (TB). Although hypotheses suggest HIV-1 disrupts Mycobacterium tuberculosis (Mtb) granuloma function, few studies have examined this directly. The objective of this study was to determine what evidence exists about the effect HIV-1 co-infection has upon Mtb granulomas. A systematic search of PubMed, Web of Science, and Medline up to 20 March 2015 was conducted, to identify studies comparing Mtb-infected tissue from HIV-1 infected and uninfected persons, or HIV-1 infected persons with stratified peripheral CD4 T cell (pCD4) counts. We summarized findings that focused on how HIV-1 changes granuloma formation, bacterial presence, cellular composition, and cytokine production. Nineteen studies with a combined sample size of 899 persons were included. Although studies frequently were limited by variable or inadequately described definitions of outcomes and analytical methods, HIV-1 was found to be associated with increased bacillary load within Mtb-infected tissue. Reductions in pCD4 counts within co-infected persons associated with both poorer granuloma formation and higher bacterial load. The high degree of heterogeneity among studies combined with experimental limitations made it difficult to conclusively support previously published and prevalent hypotheses about HIV-1/Mtb co-infection granulomas. To elucidate the validity of these hypotheses we have described areas that can be improved in future studies in order to clarify the influence HIV-1 co-infection has upon the Mtb granuloma.


Asunto(s)
Coinfección , Granuloma/microbiología , Infecciones por VIH/virología , VIH-1/patogenicidad , Mycobacterium tuberculosis/patogenicidad , Tuberculosis/microbiología , Distribución de Chi-Cuadrado , Citocinas/inmunología , Granuloma/diagnóstico , Granuloma/epidemiología , Granuloma/inmunología , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Infecciones por VIH/inmunología , VIH-1/inmunología , Interacciones Huésped-Patógeno , Humanos , Mycobacterium tuberculosis/inmunología , Oportunidad Relativa , Pronóstico , Factores de Riesgo , Tuberculosis/diagnóstico , Tuberculosis/epidemiología , Tuberculosis/inmunología
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