Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 907
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Mol Cell ; 84(1): 2-4, 2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38181761

RESUMO

Molecular Cell talks with corresponding authors Steven West and Torben Heick Jensen about the journey toward back-to-back publication of their recent Molecular Cell papers, and they share their advice for coordinating the steps along the way.

2.
Proc Natl Acad Sci U S A ; 115(22): E5243-E5249, 2018 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-29760065

RESUMO

NF-κB signaling plays a pivotal role in control of the inflammatory response. We investigated how the dynamics and function of NF-κB were affected by temperature within the mammalian physiological range (34 °C to 40 °C). An increase in temperature led to an increase in NF-κB nuclear/cytoplasmic oscillation frequency following Tumor Necrosis Factor alpha (TNFα) stimulation. Mathematical modeling suggested that this temperature sensitivity might be due to an A20-dependent mechanism, and A20 silencing removed the sensitivity to increased temperature. The timing of the early response of a key set of NF-κB target genes showed strong temperature dependence. The cytokine-induced expression of many (but not all) later genes was insensitive to temperature change (suggesting that they might be functionally temperature-compensated). Moreover, a set of temperature- and TNFα-regulated genes were implicated in NF-κB cross-talk with key cell-fate-controlling pathways. In conclusion, NF-κB dynamics and target gene expression are modulated by temperature and can accurately transmit multidimensional information to control inflammation.


Assuntos
Regulação da Expressão Gênica/fisiologia , NF-kappa B/metabolismo , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Animais , Linhagem Celular Tumoral , Células Cultivadas , Citocinas/metabolismo , Regulação da Expressão Gênica/genética , Técnicas de Silenciamento de Genes , Humanos , Inflamação , Camundongos , NF-kappa B/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Temperatura , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/análise , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/genética
3.
Microvasc Res ; 126: 103906, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31330149

RESUMO

BACKGROUND: Sugar sweetened beverages (SSB) are a major source of dietary sugar and a public health concern. Glucose consumption acutely influences microvascular reactivity in healthy adults, possibly via oxidative stress. The purpose of this study was to observe the acute influence of a more relevant dose of sucrose on microvascular reactivity, and to identify whether this response is influenced by the amount of vitamin C typically contained in SSB. METHODS: Thirteen ostensibly healthy adults (8 male, 5 female) performed three 1-day trials in a randomized order; the consumption of 300 ml water (control; CON), or 300 ml water with 50 g sucrose (SUGAR) or 50 g sucrose with 160 mg of vitamin C (VITC). Near infrared spectroscopy was used to determine peak reactive hyperaemia (PRH), the rate of desaturation (Slope 1) and reperfusion (Slope 2), and the total area under the reperfusion curve versus time (TRH) following 5 min of forearm cuff occlusion before and 30, 60, 90 and 120 min after test drink consumption. RESULTS: SUGAR and VITC significantly increased the total area under the curve versus time for plasma glucose (P < 0.05 for both). No changes in microvascular reactivity were observed between trials, although VITC increased Slope 1 compared to both SUGAR and CON 30 and 60 min post drink (P < 0.05 for both). CONCLUSION: The consumption of a sugar load representative of commercially available SSB did not influence microvascular reactivity. The co-ingestion of Vitamin C also failed to influence microvascular reactivity, but did increase the rate of oxygen extraction.


Assuntos
Ácido Ascórbico/administração & dosagem , Antebraço/irrigação sanguínea , Microcirculação/efeitos dos fármacos , Sacarose/administração & dosagem , Administração Oral , Inglaterra , Feminino , Humanos , Hiperemia , Masculino , Fluxo Sanguíneo Regional , Fatores de Tempo , Adulto Jovem
4.
AIDS Behav ; 22(9): 2916-2946, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29869184

RESUMO

We conducted a systematic review of safer conception strategies (SCS) for HIV-affected couples in sub-Saharan Africa to inform evidence-based safer conception interventions. Following PRISMA guidelines, we searched fifteen electronic databases using the following inclusion criteria: SCS research in HIV-affected couples; published after 2007; in sub-Saharan Africa; primary research; peer-reviewed; and addressed a primary topic of interest (SCS availability, feasibility, and acceptability, and/or education and promotion). Researchers independently reviewed each study for eligibility using a standardized tool. We categorize studies by their topic area. We identified 41 studies (26 qualitative and 15 quantitative) that met inclusion criteria. Reviewed SCSs included: antiretroviral therapy (ART), pre-exposure prophylaxis, timed unprotected intercourse, manual/self-insemination, sperm washing, and voluntary male medical circumcision (VMMC). SCS were largely unavailable outside of research settings, except for general availability (i.e., not specifically for safer conception) of ART and VMMC. SCS acceptability was impacted by low client and provider knowledge about safer conception services, stigma around HIV-affected couples wanting children, and difficulty with HIV disclosure in HIV-affected couples. Couples expressed desire to learn more about SCS; however, provider training, patient education, SCS promotions, and integration of reproductive health and HIV services remain limited. Studies of provider training and couple-based education showed improvements in communication around fertility intentions and SCS knowledge. SCS are not yet widely available to HIV-affected African couples. Successful implementation of SCS requires that providers receive training on effective SCS and provide couple-based safer conception counseling to improve disclosure and communication around fertility intentions and reproductive health.


Assuntos
Antirretrovirais/uso terapêutico , Circuncisão Masculina , Infecções por HIV/prevenção & controle , Acessibilidade aos Serviços de Saúde , Inseminação Artificial , Profilaxia Pré-Exposição , Comportamento Reprodutivo , África Subsaariana , Aconselhamento , Revelação , Feminino , Fertilidade , Fertilização , Infecções por HIV/transmissão , Heterossexualidade , Humanos , Intenção , Masculino , Cuidado Pré-Concepcional , Saúde Reprodutiva , Parceiros Sexuais , Estigma Social
6.
Hum Reprod ; 32(2): 423-431, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28031324

RESUMO

STUDY QUESTION: What are the respective roles of polycystic ovary syndrome (PCOS), long-term weight gain and obesity for the development of prediabetes or Type 2 diabetes mellitus (T2DM) by age 46 years? SUMMARY ANSWER: The risk of T2DM in women with PCOS is mainly due to overweight and obesity, although these two factors have a synergistic effect on the development of T2DM. WHAT IS KNOWN ALREADY: PCOS is associated with an increased risk of prediabetes and T2DM. However, the respective roles of PCOS per se and BMI for the development of T2DM have remained unclear. STUDY DESIGN, SIZE, DURATION: In a prospective, general population-based follow-up birth cohort 1966 (n = 5889), postal questionnaires were sent at ages 14 (95% answered), 31 (80% answered) and 46 years (72% answered). Questions about oligoamenorrhoea and hirsutism were asked at age 31 years, and a question about PCOS diagnosis at 46 years. Clinical examination and blood sampling were performed at 31 years in 3127 women, and at 46 years in 3280 women. A 2-h oral glucose tolerance test (OGTT) was performed at 46 years of age in 2780 women. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women reporting both oligoamenorrhoea and hirsutism at age 31 years and/or diagnosis of PCOS by 46 years were considered as women with PCOS (n = 279). Women without any symptoms at 31 years and without PCOS diagnosis by 46 years were considered as controls (n = 1577). The level of glucose metabolism was classified according to the results of the OGTT and previous information of glucose metabolism status from the national drug and hospital discharge registers. MAIN RESULTS AND THE ROLE OF CHANCE: PCOS per se significantly increased the risk of T2DM in overweight/obese (BMI ≥ 25.0 kg/m2) women with PCOS when compared to overweight/obese controls (odds ratio: 2.45, 95% CI: 1.28-4.67). Normal weight women with PCOS did not present with an increased risk of prediabetes or T2DM. The increase in weight between ages 14, 31 and 46 years was significantly greater in women with PCOS developing T2DM than in women with PCOS and normal glucose tolerance, with the most significant increase occurring in early adulthood (between 14 and 31 years: median with [25%; 75% quartiles]: 27.25 kg [20.43; 34.78] versus 13.80 kg [8.55; 20.20], P < 0.001). LIMITATIONS, REASONS FOR CAUTION: The diagnosis of PCOS was based on self-reporting, and the questionnaire at 46 years did not distinguish between polycystic ovaries only in ultrasonography and the syndrome. Ovarian ultrasonography was not available to aid the diagnosis of PCOS. WIDER IMPLICATIONS OF THE FINDINGS: These results emphasize weight management already during adolescence and early adulthood to prevent the development of T2DM in women with PCOS, as the period between 14 and 31 years seems to be a crucial time-window during which the women with PCOS who are destined to develop T2DM by 46 years of age experience a dramatic weight gain. Furthermore, our results support the view that, particularly in times of limited sources of healthcare systems, OGTT screening should be targeted to overweight/obese women with PCOS rather than to all women with PCOS. STUDY FUNDING/COMPETING INTERESTS: Finnish Medical Foundation; North Ostrobothnia Regional Fund; Academy of Finland (project grants 104781, 120315, 129269, 1114194, 24300796, Center of Excellence in Complex Disease Genetics and SALVE); Sigrid Juselius Foundation; Biocenter Oulu; University Hospital Oulu and University of Oulu (75617); Medical Research Center Oulu; National Institute for Health Research (UK); National Heart, Lung, and Blood Institute (grant 5R01HL087679-02) through the STAMPEED program (1RL1MH083268-01); National Institute of Health/National Institute of Mental Health (5R01MH63706:02); ENGAGE project and grant agreement HEALTH-F4-2007-201413; EU FP7 EurHEALTHAgeing-277849 European Commission and Medical Research Council, UK (G0500539, G0600705, G1002319, PrevMetSyn/SALVE) and Medical Research Center, Centenary Early Career Award. The authors have no conflicts of interests. TRIAL REGISTRATION NUMBER: N/A.


Assuntos
Diabetes Mellitus Tipo 2/etiologia , Obesidade/complicações , Sobrepeso/complicações , Síndrome do Ovário Policístico/complicações , Estado Pré-Diabético/etiologia , Adulto , Índice de Massa Corporal , Peso Corporal/fisiologia , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Teste de Tolerância a Glucose , Humanos , Pessoa de Meia-Idade , Obesidade/fisiopatologia , Sobrepeso/fisiopatologia , Síndrome do Ovário Policístico/fisiopatologia , Estado Pré-Diabético/fisiopatologia , Estudos Prospectivos , Fatores de Risco
7.
J Evol Biol ; 30(4): 806-813, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28181358

RESUMO

It is commonly assumed that in order for animal signals to be advantageous, the information being signalled could not have been obtained otherwise, and is therefore 'cryptic' or 'private'. Here, we suggest a scenario in which individuals can gain an advantage by signalling 'public' information that is neither cryptic nor private. In that scenario, signalling increases the efficiency with which that 'public' information is transmitted. We formalize our idea with a game in which offspring can signal their condition to their parents. Specifically, we consider a resource-strapped parent who can only invest in one of its two offspring, and we allow offspring the chance to influence parental investment through a signal. A parent in the game seeks to invest in the higher-quality offspring, which it could identify either through a publicly available cue, such as body size, or by relying on a signal provided by the offspring. We find that if the signal can convey information about offspring quality more efficiently than cues, then signalling of condition between offspring and parents can be favoured by selection, even though parents could potentially have acquired the same information from the cue. Our results suggest that the biological function of signals may be broader than currently considered, and provide a scenario where low cost signalling can be favoured. More generally, efficiency benefits could explain signalling across a range of biological and economic scenarios.


Assuntos
Comunicação Animal , Tamanho Corporal , Sinais (Psicologia) , Animais
8.
J Evol Biol ; 30(2): 352-360, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28000957

RESUMO

When competing for space and resources, bacteria produce toxins known as bacteriocins to gain an advantage over competitors. Recent studies in the laboratory have confirmed theoretical predictions that bacteriocin production can determine coexistence, by eradicating sensitive competitors or driving the emergence of resistant genotypes. However, there is currently limited evidence that bacteriocin-mediated competition influences the coexistence and distribution of genotypes in natural environments, and what factors drive interactions towards inhibition remain unclear. Using natural soil populations of Pseudomonas fluorescens, we assessed the ability of the isolates to inhibit one another with respect to spatial proximity in the field, genetic similarity and niche overlap. The majority of isolates were found to produce bacteriocins; however, widespread resistance between coexisting isolates meant relatively few interactions resulted in inhibition. When inhibition did occur, it occurred more frequently between ecologically similar isolates. However, in contrast with results from other natural populations, we found no relationship between the frequency of inhibition and the genetic similarity of competitors. Our results suggest that bacteriocin production plays an important role in mediating competition over resources in natural settings and, by selecting for isolates resistant to local bacteriocin production, can influence the assembly of natural populations of P. fluorescens.


Assuntos
Bacteriocinas/análise , Pseudomonas fluorescens/química , Variação Genética , Dinâmica Populacional , Microbiologia do Solo
9.
Am J Transplant ; 16(1): 181-93, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26361242

RESUMO

Donation after cardiac death is an important source of transplantable organs, but evidence suggests donor warm ischemia contributes to inferior outcomes. Attempts to predict recipient outcome using donor hemodynamic measurements have not yielded statistically significant results. We evaluated novel measures of donor hemodynamics as predictors of delayed graft function and graft failure in a cohort of 1050 kidneys from 566 donors. Hemodynamics were described using regression line slopes, areas under the curve, and time beyond thresholds for systolic blood pressure, oxygen saturation, and shock index (heart rate divided by systolic blood pressure). A logistic generalized estimation equation model showed that area under the curve for systolic blood pressure was predictive of delayed graft function (above median: odds ratio 1.42, 95% confidence interval [CI] 1.06-1.90). Multivariable Cox regression demonstrated that slope of oxygen saturation during the first 10 minutes after extubation was associated with graft failure (below median: hazard ratio 1.30, 95% CI 1.03-1.64), with 5-year graft survival of 70.0% (95%CI 64.5%-74.8%) for donors above the median versus 61.4% (95%CI 55.5%-66.7%) for those below the median. Among older donors, increased shock index slope was associated with increased hazard of graft failure. Validation of these findings is necessary to determine the utility of characterizing donor warm ischemia to predict recipient outcome.


Assuntos
Morte , Função Retardada do Enxerto/mortalidade , Rejeição de Enxerto/mortalidade , Hemodinâmica/fisiologia , Nefropatias/cirurgia , Transplante de Rim/efeitos adversos , Obtenção de Tecidos e Órgãos , Adulto , Idoso , Idoso de 80 Anos ou mais , Função Retardada do Enxerto/etiologia , Feminino , Rejeição de Enxerto/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida , Doadores de Tecidos , Resultado do Tratamento , Isquemia Quente , Adulto Jovem
10.
J Evol Biol ; 29(3): 551-9, 2016 03.
Artigo em Inglês | MEDLINE | ID: mdl-26663204

RESUMO

A key step in the evolution of multicellular organisms is the formation of cooperative multicellular groups. It has been suggested that predation pressure may promote multicellular group formation in some algae and bacteria, with cells forming groups to lower their chance of being eaten. We use the green alga Chlorella vulgaris and the protist Tetrahymena thermophila to test whether predation pressure can initiate the formation of colonies. We found that: (1) either predators or just predator exoproducts promote colony formation; (2) higher predator densities cause more colonies to form; and (3) colony formation in this system is facultative, with populations returning to being unicellular when the predation pressure is removed. These results provide empirical support for the hypothesis that predation pressure promotes multicellular group formation. The speed of the reversion of populations to unicellularity suggests that this response is due to phenotypic plasticity and not evolutionary change.


Assuntos
Chlorella vulgaris/fisiologia , Tetrahymena thermophila/fisiologia , Animais , Evolução Biológica , Comportamento Predatório
11.
J Evol Biol ; 29(9): 1728-36, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27223690

RESUMO

Microbes engage in cooperative behaviours by producing and secreting public goods, the benefits of which are shared among cells, and are therefore susceptible to exploitation by nonproducing cheats. In nature, bacteria are not typically colonizing sterile, rich environments in contrast to laboratory experiments, which involve inoculating sterile culture with few bacterial cells that then race to fill the available niche. Here, we study the potential implications of this difference, using the production of pyoverdin, an iron-scavenging siderophore that acts as a public good in the bacteria Pseudomonas aeruginosa. We show that (1) nonproducers are able to invade cultures of producers when added at the start of growth or during early exponential growth phase, but not during late exponential or stationary phase; (2) the producer strain does not produce pyoverdin in the late exponential and stationary phases and so is not paying the cost of cooperating during those phases. These results suggest that whether a nonproducing mutant can invade will depend upon when the mutation arises, as well as the population structure, and raise a potential difficulty with the use of antimicrobial treatment strategies that propose to exploit the invasive abilities of cheats.


Assuntos
Oligopeptídeos/metabolismo , Pseudomonas aeruginosa , Adaptação Fisiológica , Ferro , Sideróforos
12.
Practitioner ; 260(1793): 30-2, 3, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27382917

RESUMO

The most common cause of adolescent heel pain is calcaneal apophysitis also known as Sever's disease. The condition may occur in adolescent athletes, particularly those involved in running or jumping activities, during the pubertal growth spurt. The mean age of presentation in Sever's disease is ten, (range 7-15). It presents with posterior heel pain that is worse with activity and relieved by rest in most cases. Sever's disease, Osgood Schlatter's disease (tibial tuberosity) and Sinding-Larsen Johansson syndrome (distal patella) are all overuse syndromes brought about by repetitive submaximal loading and microtrauma. They are, however, entirely self-limiting and resolve at skeletal maturity or earlier. Careful assessment is required to differentiate them from other rare pathologies. Achilles tendinitis is rare under the age of 14. As in Sever's disease, it may occur in jumping athletes, those who suddenly increase their sporting activities and in individuals with relative gastrosoleus tightness. It may also occur in those with inflammatory arthropathies and merit rheumatological investigation if there are other suggestive signs or symptoms. Benign and malignant tumours of the adolescent calcaneus are extremely rare In a unilateral case, atypical features such as night pain or absence of a precipitating activity should raise the index of suspicion. There may be localised swelling and bony expansion.


Assuntos
Calcâneo , Transtornos Traumáticos Cumulativos , Calcanhar , Dor , Adolescente , Traumatismos em Atletas/complicações , Bursite/complicações , Bursite/fisiopatologia , Calcâneo/patologia , Calcâneo/fisiopatologia , Criança , Transtornos Traumáticos Cumulativos/diagnóstico , Transtornos Traumáticos Cumulativos/etiologia , Transtornos Traumáticos Cumulativos/fisiopatologia , Diagnóstico Diferencial , Calcanhar/patologia , Calcanhar/fisiopatologia , Humanos , Dor/diagnóstico , Dor/etiologia , Medição da Dor/métodos , Tendinopatia/complicações , Tendinopatia/fisiopatologia
13.
Am J Transplant ; 15(11): 2978-85, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26082322

RESUMO

Allosensitized children listed with a requirement for a negative prospective crossmatch have high mortality. Previously, we found that listing with the intent to accept the first suitable organ offer, regardless of the possibility of a positive crossmatch (TAKE strategy), results in a survival advantage from the time of listing compared to awaiting transplantation across a negative crossmatch (WAIT). The cost-effectiveness of these strategies is unknown. We used Markov modeling to compare cost-effectiveness between these waitlist strategies for allosensitized children listed urgently for heart transplantation. We used registry data to estimate costs and waitlist/posttransplant outcomes. We assumed patients remained in hospital after listing, no positive crossmatches for WAIT, and a base-case probability of a positive crossmatch of 47% for TAKE. Accepting the first suitable organ offer cost less ($405 904 vs. $534 035) and gained more quality-adjusted life years (3.71 vs. 2.79). In sensitivity analyses, including substitution of waitlist data from children with unacceptable antigens specified during listing, TAKE remained cost-saving or cost-effective. Our findings suggest acceptance of the first suitable organ offer for urgently listed allosensitized pediatric heart transplant candidates is cost-effective and transplantation should not be denied because of allosensitization status alone.


Assuntos
Redução de Custos , Transplante de Coração/economia , Transplante de Coração/métodos , Teste de Histocompatibilidade/economia , Listas de Espera , Criança , Pré-Escolar , Estudos de Coortes , Análise Custo-Benefício , Bases de Dados Factuais , Emergências , Feminino , Rejeição de Enxerto , Sobrevivência de Enxerto , Transplante de Coração/efeitos adversos , Teste de Histocompatibilidade/métodos , Custos Hospitalares , Humanos , Lactente , Masculino , Cadeias de Markov , Seleção de Pacientes , Pediatria , Prognóstico , Sistema de Registros , Medição de Risco , Sensibilidade e Especificidade , Fatores de Tempo , Resultado do Tratamento
14.
J Intern Med ; 278(1): 19-28, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25758353

RESUMO

Men and women with chronic kidney disease (CKD) are at an increased risk of fracture, and this risk increases as kidney function deteriorates. Fractures are associated with morbidity, mortality and economic costs. Despite this, there is a paucity of data regarding how to evaluate risk for fractures in CKD and how to treat high-risk patients. Evidence suggests that bone mineral density (BMD) as assessed by dual-energy X-ray absorptiometry (DXA) is associated with fractures and can also predict future fractures in predialysis (stages 1-3) patients with CKD. In the absence of considerable abnormalities in markers of mineral metabolism, treatment with antiresorptive agents in men and women with early CKD at high fracture risk may be appropriate. Of note, recent data suggest that low BMD as measured by DXA can also predict fractures in patients with more advanced CKD (stages 4, 5 and 5D). However, treatment in patients with advanced CKD requires bone biopsy, the gold standard to assess bone turnover, prior to treatment. Further research, focusing on noninvasive methods to assess fracture risk and bone turnover, together with randomized controlled trials of treatments to reduce fractures in patients at all stages of CKD, is required.


Assuntos
Fraturas Ósseas/etiologia , Fraturas Ósseas/prevenção & controle , Osteoporose/complicações , Insuficiência Renal Crônica/complicações , Medição de Risco , Absorciometria de Fóton , Densidade Óssea , Conservadores da Densidade Óssea/uso terapêutico , Humanos , Osteoporose/prevenção & controle
15.
Osteoporos Int ; 26(2): 449-58, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25477230

RESUMO

SUMMARY: The utility of bone mineral density (BMD) testing in chronic kidney disease (CKD) is not known. We performed a meta-analysis of studies reporting on BMD and fracture in CKD. All but one study was cross-sectional. BMD was lower in those with CKD and fractures compared to those without fractures. INTRODUCTION: CKD is associated with an increased risk of fracture. The utility of dual energy X-ray absorptiometry (DXA) to assess fracture risk in CKD is unknown. METHODS: We performed an updated meta-analysis and systematic review of published studies that reported on the association between DXA and fracture (morphometric spine or clinical nonspine) in predialysis and dialysis CKD. We identified 2,894 potential publications, retrieved 292 for detailed review, and included 13. All but one study was cross-sectional and three reported on the ability of DXA to discriminate fracture status in predialysis CKD. Results were pooled using a random effects model and statistical heterogeneity was assessed using the I2 statistic. RESULTS: BMD was statistically significantly lower at the femoral neck, lumbar spine, the 1/3 and ultradistal radius in subjects with fractures compared to those without regardless of dialysis status. For example, femoral neck BMD was 0.06 g/cm2 lower in dialysis subjects and 0.102 g/cm2 lower in predialysis subjects with fractures compared to those without. Lumbar spine BMD was 0.05 g/cm2 lower in dialysis subjects and 0.108 g/cm2 lower in predialysis subjects with fractures compared to those without. Our meta-analysis was limited to studies with small numbers of subjects and even smaller numbers of fractures. All of the studies were observational and only one was prospective. There was statistical heterogeneity at the lumbar spine, 1/3 and ultradistal radius. CONCLUSIONS: Our findings suggest that BMD can discriminate fracture status in predialysis and dialysis CKD. Larger, prospective studies are needed.


Assuntos
Densidade Óssea/fisiologia , Osso e Ossos/diagnóstico por imagem , Fraturas por Osteoporose/complicações , Insuficiência Renal Crônica/complicações , Absorciometria de Fóton , Idoso , Humanos , Pessoa de Meia-Idade , Fatores de Risco
16.
J Evol Biol ; 28(12): 2264-74, 2015 12.
Artigo em Inglês | MEDLINE | ID: mdl-26348785

RESUMO

The production of beneficial public goods is common in the microbial world, and so is cheating--the exploitation of public goods by nonproducing mutants. Here, we examine co-evolutionary dynamics between cooperators and cheats and ask whether cooperators can evolve strategies to reduce the burden of exploitation, and whether cheats in turn can improve their exploitation abilities. We evolved cooperators of the bacterium Pseudomonas aeruginosa, producing the shareable iron-scavenging siderophore pyoverdine, together with cheats, defective in pyoverdine production but proficient in uptake. We found that cooperators managed to co-exist with cheats in 56% of all replicates over approximately 150 generations of experimental evolution. Growth and competition assays revealed that co-existence was fostered by a combination of general adaptions to the media and specific adaptions to the co-evolving opponent. Phenotypic screening and whole-genome resequencing of evolved clones confirmed this pattern, and suggest that cooperators became less exploitable by cheats because they significantly reduced their pyoverdine investment. Cheats, meanwhile, improved exploitation efficiency through mutations blocking the costly pyoverdine-signalling pathway. Moreover, cooperators and cheats evolved reduced motility, a pattern that likely represents adaptation to laboratory conditions, but at the same time also affects social interactions by reducing strain mixing and pyoverdine sharing. Overall, we observed parallel evolution, where co-existence of cooperators and cheats was enabled by a combination of adaptations to the abiotic and social environment and their interactions.


Assuntos
Evolução Biológica , Pseudomonas aeruginosa/genética , Adaptação Fisiológica , Genes Bacterianos , Mutação , Polimorfismo de Nucleotídeo Único , Pseudomonas aeruginosa/fisiologia
17.
Nutr Metab Cardiovasc Dis ; 25(1): 52-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25240692

RESUMO

BACKGROUND AND AIMS: Little is known about the effect of various dietary fatty acids on pro- and anti-inflammatory processes. We investigated the effect of 5 oils containing various amounts of alpha-linolenic acid (ALA), linoleic acid (LA), oleic acid (OA) and docosahexaenoic acid (DHA) on plasma inflammatory biomarkers and expression levels of key inflammatory genes and transcription factors in whole blood cells. METHODS AND RESULTS: In a randomized, crossover controlled nutrition intervention, 114 adult men and women with abdominal obesity and at least one other criterion for the metabolic syndrome consumed 5 experimental isoenergetic diets for 4 weeks each, separated by 4-week washout periods. Each diet provided 60 g/3000 kcal of different oils: 1) control corn/safflower oil blend (CornSaff; LA-rich), 2) flax/safflower oil blend (FlaxSaff; ALA-rich), 3) conventional canola oil (Canola; OA-rich), 4) high oleic canola oil (CanolaOleic; highest OA content), 5) DHA-enriched high oleic canola oil (CanolaDHA; OA- and DHA-rich). Gene expression in whole blood cells was assessed in a subset of 62 subjects. CanolaDHA increased plasma adiponectin concentrations compared with the control CornSaff oil treatment (+4.5%, P = 0.04) and FlaxSaff (+6.9%, P = 0.0008). CanolaDHA also reduced relative expression levels of interleukin (IL)1B compared with CornSaff and Canola (-11% and -13%, respectively, both P = 0.03). High-sensitivity C-reactive protein concentrations were lower after Canola than after FlaxSaff (-17.8%, P = 0.047). CONCLUSION: DHA-enriched canola oil exerts anti-inflammatory effects compared with polyunsaturated fatty acids from plant sources.


Assuntos
Adiponectina/agonistas , Anti-Inflamatórios não Esteroides/uso terapêutico , Ácidos Docosa-Hexaenoicos/uso terapêutico , Ácidos Graxos Monoinsaturados/uso terapêutico , Mediadores da Inflamação/antagonistas & inibidores , Síndrome Metabólica/prevenção & controle , Obesidade Abdominal/dietoterapia , Adiponectina/sangue , Adulto , Idoso , Anti-Inflamatórios não Esteroides/análise , Anti-Inflamatórios não Esteroides/química , Biomarcadores/sangue , Biomarcadores/metabolismo , Células Sanguíneas/imunologia , Células Sanguíneas/metabolismo , Índice de Massa Corporal , Canadá/epidemiologia , Estudos Cross-Over , Ácidos Docosa-Hexaenoicos/análise , Método Duplo-Cego , Ácidos Graxos Monoinsaturados/química , Feminino , Alimentos Fortificados , Regulação da Expressão Gênica , Humanos , Mediadores da Inflamação/sangue , Mediadores da Inflamação/metabolismo , Masculino , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/etiologia , Pessoa de Meia-Idade , Obesidade Abdominal/imunologia , Obesidade Abdominal/metabolismo , Obesidade Abdominal/fisiopatologia , Pennsylvania/epidemiologia , Óleo de Brassica napus , Risco , Adulto Jovem
18.
Clin Radiol ; 70(6): 614-21, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25799364

RESUMO

AIM: To estimate and compare the extent of myeloma bone disease by skeletal region using whole-body diffusion-weighted imaging (WB-DWI) and skeletal survey (SS) and record interobserver agreement, and to investigate differences in imaging assessments of disease extent and apparent diffusion coefficient (ADC) between patients with pathological high versus low disease burden. MATERIALS AND METHODS: Twenty patients with relapsed myeloma underwent WB-DWI and SS. Lesions were scored by number and size for each skeletal region by two independent observers using WB-DWI and SS. Observer scores, ADC, and ADC-defined volume of tumour-infiltrated marrow were compared between patients with high and low disease burden (assessed by serum paraproteins and marrow biopsy). RESULTS: Observer scores were higher on WB-DWI than SS in every region (p<0.05) except the skull, with greater interobserver reliability in rating the whole skeleton (WB-DWI: ICC = 0.74, 95% CI: 0.443-0.886; SS: ICC = 0.44, 95% CI: 0.002-0.730) and individual body regions. WB-DWI scores were not significantly higher in patients with high versus low disease burden (observer 1: mean ± SD: 48.8 ± 7, 38.6 ± 14.5, observer 2: mean ± SD: 37.3 ± 13.5, 30.4 ± 15.5; p = 0.06, p = 0.35). CONCLUSION: WB-DWI demonstrated more lesions than SS in all regions except the skull with greater interobserver agreement. Sensitivity is not a limiting factor when considering WB-DWI in the management pathway of patients with myeloma.


Assuntos
Doenças Ósseas/diagnóstico , Mieloma Múltiplo/diagnóstico , Idoso , Efeitos Psicossociais da Doença , Imagem de Difusão por Ressonância Magnética/métodos , Feminino , Fraturas Espontâneas/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Estudos Prospectivos , Imagem Corporal Total/métodos
19.
Hum Reprod ; 29(3): 628-33, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24324025

RESUMO

STUDY QUESTION: To what extent do self-reported oligo-amenorrhea and hirsutism affect reproductive performance (childlessness, age at first delivery, family size and miscarriage rates)? SUMMARY ANSWER: At the age of 44, among women with both self-reported oligo-amenorrhea and hirsutism the prevalence of childlessness was not significantly different from non-symptomatic women but they had a smaller family size than non-symptomatic women. WHAT IS KNOWN ALREADY: Polycystic ovary syndrome (PCOS) is a common endocrine disorder characterized by oligo-amenorrhea or amenorrhea, hyperandrogenism and hirsutism and it is the most frequent cause of anovulatory infertility, but there are few studies on the reproductive capacity of women with PCOS. In our previous population-based cohort study the women with self-reported oligo-amenorrhea and hirsutism were found to have more infertility problems and smaller family size than non-symptomatic women at the age of 31. STUDY DESIGN, SIZE, DURATION: A prospective population-based cohort study. The population of the study is derived from the prospective Northern Finland Birth Cohort 1966 (NFBC1966), comprising all expected births from the year 1966 in the two northernmost provinces of Finland (n = 12 058). Of them, 5889 were females. Enrollment in this database begun at the 24th gestational week and so far data have been collected from the subjects at the ages of 1, 14 and 31 years. PARTICIPANTS/MATERIALS, SETTING, METHODS: A postal questionnaire including questions about oligo-amenorrhea and hirsutism was sent to all women at the age of 31 (n = 5608, response rate 81%, n = 4535) and a clinical examination was performed (attendance rate 76.5%). Those who reported both hirsutism and oligo-amenorrhea were defined as women with both symptoms (n = 153). Data on pregnancies/deliveries were obtained from the Finnish Medical Birth Register (FMBR) in 2010 when the women were 44 years old. MAIN RESULTS AND THE ROLE OF CHANCE: Women with both symptoms had delivered at least one child as often as non-symptomatic women [75.2 versus 79.0%, adjusted odds ratio (OR) 0.86, 95% confidence intervals (CI) 0.57-1.30], were of similar age [mean (SD)] at first delivery [27.7 (4.81) versus 27.3 (4.71)] and had similar incidence of miscarriages. However, non-symptomatic women had more often ≥2 deliveries (61.6 versus 52.9%, adjusted OR 0.70, 95% CI 0.49-1.00, P = 0.048) and had larger family size [mean (SD)] [2.4 (1.4) versus 1.9 (0.8), P < 0.001]. Women with both symptoms had been treated more often for infertility than non-symptomatic women (6.1 versus 2.4%, adjusted OR 2.74, 95% CI 1.14-6.60, P = 0.024). LIMITATIONS, REASONS FOR CAUTION: The diagnosis of oligo-amenorrhea and hirsutism was based on a questionnaire, suggesting a risk of information bias in reporting the symptoms. However, we have previously shown that self-reported oligo-amenorrhea and hirsutism can distinguish most women with the typical profile of PCOS. Only the women who had delivered at least once were recorded in the FMBR, thus excluding from the study those who had experienced miscarriages and/or infertility treatments but did not have a live birth. This feature could potentially decrease the differences in incidence of miscarriages and/or infertility treatment between symptomatic and non-symptomatic subjects. WIDER IMPLICATIONS OF THE FINDINGS: This is one of the few studies, in which the impact of self-reported oligo-amenorrhea and hirsutism on lifetime reproductive success can be measured. Our results suggest that even at more advanced age, women with both symptoms do not quite match the parity of healthy non-symptomatic women, and that infertility treatment does not always restore normal reproductive capacity in these women. Obese women with both symptoms had the worst prognostic as regards reproduction, which emphasizes the importance of life intervention and preventive politics against obesity in this group of women. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by grants from the Finnish Medical Society Duodecim, the North Ostrobothnia Regional Fund, the Academy of Finland, University Hospital Oulu, Biocenter, University of Oulu, Finland, the European Commission and the Medical Research Council, UK, the National Institute for Health Research (NIHR). None of the authors has any conflict of interest to declare.


Assuntos
Fertilidade , Hirsutismo/epidemiologia , Síndrome do Ovário Policístico/epidemiologia , Reprodução , Adulto , Amenorreia/complicações , Índice de Massa Corporal , Estudos de Coortes , Características da Família , Feminino , Finlândia/epidemiologia , Humanos , Infertilidade Feminina/terapia , Paridade , Gravidez , Estudos Prospectivos
20.
Hum Reprod ; 29(10): 2339-51, 2014 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-25085801

RESUMO

STUDY QUESTION: Do teenage girls with a history of menstrual irregularity and/or elevated androgen levels in adolescence exhibit an increased risk of polycystic ovary syndrome (PCOS) and/or infertility later on in adulthood? SUMMARY ANSWER: Our results suggest that menstrual irregularity and/or elevated androgen levels at 16 years are still associated with symptoms of PCOS at 26 years as well as infertility problems at 26 years but not with decreased pregnancy or delivery rates at 26 years. WHAT IS KNOWN ALREADY: Hyperandrogenaemia is associated with menstrual irregularity, hirsutism, acne and potentially higher risk for PCOS, but there are few follow-up studies investigating whether adolescent hyperandrogenaemia and/or menstrual irregularity are an early sign of PCOS. STUDY DESIGN, SIZE, DURATION: A prospective population-based cohort study was conducted using two postal questionnaires targeting girls in the Northern Finland Birth Cohort 1986 (NFBC1986, n = 4567). The NFBC1986 comprises all expected births from the year 1986 in the two northernmost provinces of Finland. Collection of the database was performed at the age of 16 and 26. The 16-year and 26-year questionnaires included one question about the regularity and length of the menstrual cycle. The 26-year questionnaire also included questions about symptoms of PCOS, reproduction and infertility problems. PARTICIPANTS, SETTING, METHODS: The response rates for the questionnaires were 80% (n = 3669) at 16 years and 50% (n = 2270) at 26 years. At 15-16 years, of 2448 girls, 709 (29%) girls reported menstrual irregularity (symptomatic girls) and 1739 (71%) had regular periods (non-symptomatic girls). After combining data from the two questionnaires a total of 2033 girls were included in the analyses. The χ(2) and Student's t-test was used to compare reproductive outcome and prevalence of clinical hyperandrogenaemia, PCOS and infertility at 26 years between the study groups. Univariate and multivariate logistic regression models were employed to estimate the association of menstrual irregularity at 16 years with clinical hyperandrogenaemia, PCOS and infertility at 26 years. MAIN RESULTS AND THE ROLE OF CHANCE: At follow-up, the proportion of symptomatic girls who had conceived at least once (68.0 versus 67.9%) and had delivered at least one child (25.7 versus 28.1%) was similar to the non-symptomatic women and the groups had similar miscarriage rates (11.6 versus 12.1%). Logistic regression analyses indicated that menstrual irregularity at 16 years was associated with an increased risk of menstrual irregularity [adjusted odds ratio (OR) 1.37, 95% confidence interval (CI) 1.00-1.88, P = 0.050], PCOS (adjusted OR 2.91, 95% CI 1.74-4.84, P < 0.001) and infertility problems (adjusted OR 2.07, 95% CI 1.16-3.76, P = 0.013) at 26 years. At 26 years, women with PCOS (P = 0.013), hirsutism (P = 0.001) and acne (P < 0.001) exhibited significantly higher values of free androgen index (FAI) at 16 years than control women. There was a significant linear trend in the higher FAI quartiles at 16 years towards higher prevalence of PCOS (P = 0.005), hirsutism (P < 0.001) and acne (P < 0.001) at 26 years. Only 10.5% of the girls with menstrual irregularity at 16 years had PCOS at 26 years. LIMITATIONS, REASONS FOR CAUTION: The diagnosis of menstrual irregularity was based on a self-reported questionnaire, thus introducing a risk of information bias in reporting the symptoms. Moreover, ovarian ultrasonography was not available to aid the diagnosis of PCOS and there was no clinical evaluation of hyperandrogenism. The relatively low rate of participation to the questionnaire at 26 years may also have biased the results. WIDER IMPLICATIONS OF THE FINDINGS: Our findings confirm that menstrual irregularity and/or elevated androgen levels are already present in adolescence in women with PCOS and infertility in later life, which strengthens the importance of early identification of menstrual irregularity. STUDY FUNDING/COMPETING INTERESTS: This work was supported by grants from the Finnish Medical Society Duodecim, the North Ostrobothnia Regional Fund, the Academy of Finland, the Sigrid Juselius Foundation, University Hospital Oulu and University of Oulu, the European Commission and the Medical Research Council, UK, Welcome Trust (089549/Z/09/Z). None of the authors have any conflict of interest.


Assuntos
Hiperandrogenismo/complicações , Infertilidade Feminina/complicações , Distúrbios Menstruais/complicações , Síndrome do Ovário Policístico/complicações , Adolescente , Adulto , Feminino , Finlândia , Seguimentos , Humanos , Hiperandrogenismo/epidemiologia , Síndrome do Ovário Policístico/epidemiologia , Prevalência , Testosterona/sangue
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA