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Remote observations of the asteroid (1) Ceres from ground- and space-based telescopes have provided its approximate density and shape, leading to a range of models for the interior of Ceres, from homogeneous to fully differentiated. A previously missing parameter that can place a strong constraint on the interior of Ceres is its moment of inertia, which requires the measurement of its gravitational variation together with either precession rate or a validated assumption of hydrostatic equilibrium. However, Earth-based remote observations cannot measure gravity variations and the magnitude of the precession rate is too small to be detected. Here we report gravity and shape measurements of Ceres obtained from the Dawn spacecraft, showing that it is in hydrostatic equilibrium with its inferred normalized mean moment of inertia of 0.37. These data show that Ceres is a partially differentiated body, with a rocky core overlaid by a volatile-rich shell, as predicted in some studies. Furthermore, we show that the gravity signal is strongly suppressed compared to that predicted by the topographic variation. This indicates that Ceres is isostatically compensated, such that topographic highs are supported by displacement of a denser interior. In contrast to the asteroid (4) Vesta, this strong compensation points to the presence of a lower-viscosity layer at depth, probably reflecting a thermal rather than compositional gradient. To further investigate the interior structure, we assume a two-layer model for the interior of Ceres with a core density of 2,460-2,900 kilograms per cubic metre (that is, composed of CI and CM chondrites), which yields an outer-shell thickness of 70-190 kilometres. The density of this outer shell is 1,680-1,950 kilograms per cubic metre, indicating a mixture of volatiles and denser materials such as silicates and salts. Although the gravity and shape data confirm that the interior of Ceres evolved thermally, its partially differentiated interior indicates an evolution more complex than has been envisioned for mid-sized (less than 1,000 kilometres across) ice-rich rocky bodies.
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Lameness is a major concern to animal health and welfare within the dairy industry. Our objectives were to describe the prevalence of lameness in high-producing cows on farms with automated milking systems (AMS) and to identify the main risk factors for lameness at the animal and farm level. We visited 36 AMS farms across Canada and Michigan. Farm-level factors related to stall design, bedding use, flooring, and stocking rates were recorded by trained observers. Cows were scored for lameness, leg injuries, body condition (BCS), and body size (hip width and rump height; n=1,378; 25-40 cows/farm). Mean herd prevalence of clinical lameness was 15% (range=2.5-46%). Stall width relative to cow size and parity was found to be the most important factor associated with lameness. Not fitting the average stall width increased the odds of being lame 3.7 times in primiparous cows. A narrow feed alley [<430cm; odds ratio (OR)=1.9], obstructed lunge space (OR=1.7), a low BCS (OR=2.1 for BCS ≤2.25 compared with BCS 2.75-3.0), and presence of hock lesions (OR=1.6) were also identified as important risk factors for lameness. Only 1 of 36 farms had stalls of adequate width and length for the cows on their farm. For lameness prevention, it can be concluded that more emphasis needs be placed on either building stalls of appropriate width or selecting for smaller-framed cows that fit the existing stalls.
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Indústria de Laticínios , Coxeadura Animal/epidemiologia , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Fazendas , Feminino , Abrigo para Animais , Fatores de RiscoRESUMO
Lying down and resting are important for optimal cow health, welfare, and production. In comparison with free stall farms with a milking parlor, farms with automated milking systems (AMS) may place less constraint on how long cows can lie down. However, few studies report lying times on AMS farms. The aims of this study were to describe the variation in lying times of dairy cows in AMS farms and to understand how much of the variation in individual lying times is related to cow-level factors, including lameness, the presence of hock and knee lesions, and body condition score (BCS). We visited 36 farms in Canada (Quebec: n = 10; Ontario: n = 10; British Columbia: n = 4; and Alberta: n = 5), and the United States (Michigan: n = 7). Gait scores, presence of hock and knee lesions, and BCS were recorded for 40 Holstein cows from each herd. Parity and days in milk were retrieved from farm records. Lying time was recorded across 4d using accelerometers (n = 1,377). Multivariable analysis was performed. Of scored cows, 15.1% were lame (i.e., obviously limping; 203 of 1,348 cows). Knee lesions were found in 27.1% (340 of 1,256 cows) and hock lesions were found in 30.8% (421 of 1,366 cows) of the animals. Daily lying time varied among cows. Cows spent a median duration of 11.4 h/d lying down (25th-75th percentile = 9.7-12.9 h), with a lying bout frequency of 9.5 bouts/d (25th-75th percentile = 7.5-12 bouts/d) and a median bout duration of 71 min (25th-75th percentile = 58-87 min/bout). Lameness was associated with cows lying down for 0.6 h/d longer in fewer, longer bouts. Increased lying time was also associated with increased parity, later stage of lactation and higher BCS. Older cows (parity ≥ 3) spent about 0.5 h/d more lying down compared with parity 1 cows, and cows with BCS ≥ 3.5 lay down on average 1 h/d longer than cows with BCS ≤ 2.25. Hock lesions were associated with shorter lying times in univariable models, but no associations were found in the multivariable models. We concluded that only a small proportion of the variation between cows in lying time is explained by lameness, leg lesions, and BCS.
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Comportamento Animal , Doenças dos Bovinos/fisiopatologia , Coxeadura Animal/fisiopatologia , Animais , Canadá/epidemiologia , Bovinos , Indústria de Laticínios , Feminino , Marcha , Abrigo para Animais , Lactação , Michigan/epidemiologia , Paridade , Postura , Gravidez , Fatores de TempoRESUMO
INTRODUCTION AND OBJECTIVES: Although economic evaluations of haemophilia-related care have highlighted both the health care payer and societal perspectives, the costs to families with children with haemophilia have not been examined. This study determined the costs incurred by families of children with haemophilia, attending a haemophilia treatment centre (HTC), servicing a large geographical area in Eastern Canada. METHODS: Families recorded all direct and indirect costs associated with haemophilia-related care for a year. Costs incurred to receive care at the HTC and local health care centres were compared. The relationship between distance to the HTC and costs was modelled using linear regression. RESULTS: Participants included 31/45 children (68%) from 27 families attending the HTC. Median age was 12 years (range: 0.5-17 years); 24/31 (77%) had severe haemophilia. The median distance to the HTC and local health care facility was 230 km (range: 7-600 km) and 33.5 km (range: 2-400 km) respectively. Due to this difference in distance, 23/31 (74%) children do not attend the HTC for management of acute haemorrhage. The median annual total cost per family to attend the HTC is $775.93 (range: $200.00-$5741.00). The total cost to attend the HTC increases by $2.16 (95% CI 1.24-3.9) per kilometer from the HTC. The median total annual cost of haemophilia-related care per family is $1222.50 (range: $396.00-$8037.00). CONCLUSION: Families incur high costs related to haemophilia care. The distance to the HTC is a barrier to care. Improving access to HTCs is paramount in improving haemophilia-related outcomes.
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Efeitos Psicossociais da Doença , Hemofilia A/economia , Adolescente , Criança , Pré-Escolar , Atenção à Saúde/economia , Hemofilia A/patologia , Humanos , Lactente , Masculino , Qualidade de VidaRESUMO
Seasonal acclimatization in terrestrial mammals in the Northern Hemisphere involves changes in coat insulation. It is more economical to provide increased insulation than increased heat production for protection against the cold. This study was done to test a technique for the non-invasive measurement of mammal coat insulation and to measure coat insulation over several seasons on captive exotics. The working hypothesis was that species that have no coat or have a coat that does not change seasonally do not acclimatize seasonally. Three surface temperature readings were measured from the torso area. The insulation was calculated using measured metabolic rates and body temperature when possible. The African elephants, giraffe and okapi did not acclimatize with average maximum insulation values of 0.256°Cm(2) W(-1) . The Amur tigers and mountain goats acclimatized to seasonal ambient conditions by increasing the insulation values of the hair coats in the cold with an average maximum insulation values of 0.811°Cm(2) W(-1) . The cold adapted species are more than three times more insulated in the cold than the equatorial species. The husbandry implications of exotics that have no ability to acclimatize to Northern Hemisphere seasonal ambient changes are profound. Giraffe, African elephants, and okapi when exposed to cold conditions with ambient air temperatures below 21°C will use body energy reserves to maintain a heat balance and will require housing that provides ambient conditions of 21°C.
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Aclimatação/fisiologia , Animais de Zoológico/fisiologia , Temperatura Baixa , Cabelo/fisiologia , Estações do Ano , Animais , Animais de Zoológico/crescimento & desenvolvimento , Regulação da Temperatura CorporalRESUMO
Necrotising fasciitis is an uncommon life-threatening surgical emergency. While most commonly seen in the lower limb it can also affect the upper limb. This article reviews and summarises the current literature on necrotising fasciitis in the upper limb, covering common predisposing factors, clinical presentations, scoring systems, common organism types and the timing of surgical treatment. The key to managing this condition continues to be early clinical diagnosis and aggressive surgical debridement to attempt to reduce the morbidity and mortality of this condition.
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OBJECTIVE: This retrospective study was designed to assess the effects of the combination of pioglitazone and extended-release niacin on the lipid panel, particularly HDL-cholesterol, when used in patients with type 2 diabetes in an endocrinology specialty practice. METHODS: The electronic medical records of 434 adult patients with type 2 diabetes receiving extended-release niacin and pioglitazone were screened for review. Patients with type 2 diabetes and hyperlipidemia were included for review if they received the combination of pioglitazone at doses ≥ 15 mg/day and extended-release niacin (Niaspan) at doses ≥ 1000 mg/day for ≥6 months. Statistical analysis used paired t-tests with p < 0.05 as statistically significant. Both ANOVA and the Tukey-Kramer test for multiple comparisons (α = 0.05) were also used. RESULTS: A total of 47 patients, 83% were men with average age of 58, met all eligibility criteria for the study. Compared with baseline, a statistically significant increase in HDL-C (+ 25.13%, p < 0.0001) was observed at the conclusion of combination therapy. The HDL-C levels progressively increased with duration of combination treatment, and were not correlated with concomitant statin use. Significant decreases in total cholesterol and triglycerides were detected, and HbA1c decreased 0.84% during combination therapy for all therapies combined. CONCLUSION: The combination of pioglitazone and extended-release niacin in patients with type 2 diabetes and hyperlipidemia, used in commonly prescribed doses for at least 6 months, resulted in statistically significant improvements in HDL-C, total cholesterol, and triglycerides, and did not result in deteriorations in glycemic control.
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HDL-Colesterol/efeitos dos fármacos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Hipolipemiantes/administração & dosagem , Niacina/administração & dosagem , Tiazolidinedionas/administração & dosagem , Análise de Variância , HDL-Colesterol/metabolismo , Preparações de Ação Retardada , Diabetes Mellitus Tipo 2/sangue , Quimioterapia Combinada , Feminino , Intolerância à Glucose/prevenção & controle , Hemoglobinas Glicadas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Pioglitazona , Estudos Retrospectivos , Resultado do TratamentoRESUMO
14-3-3s are abundant proteins that regulate essentially all aspects of cell biology, including cell cycle, motility, metabolism, and cell death. 14-3-3s work by docking to phosphorylated Ser/Thr residues on a large network of client proteins and modulating client protein function in a variety of ways. In recent years, aided by improvements in proteomics, the discovery of 14-3-3 client proteins has far outpaced our ability to understand the biological impact of individual 14-3-3 interactions. The rate-limiting step in this process is often the identification of the individual phospho-serines/threonines that mediate 14-3-3 binding, which are difficult to distinguish from other phospho-sites by sequence alone. Furthermore, trial-and-error molecular approaches to identify these phosphorylations are costly and can take months or years to identify even a single 14-3-3 docking site phosphorylation. To help overcome this challenge, we used machine learning to analyze predictive features of 14-3-3 binding sites. We found that accounting for intrinsic protein disorder and the unbiased mass spectrometry identification rate of a given phosphorylation significantly improves the identification of 14-3-3 docking site phosphorylations across the proteome. We incorporated these features, coupled with consensus sequence prediction, into a publicly available web app, called "14-3-3 site-finder". We demonstrate the strength of this approach through its ability to identify 14-3-3 binding sites that do not conform to the loose consensus sequence of 14-3-3 docking phosphorylations, which we validate with 14-3-3 client proteins, including TNK1, CHEK1, MAPK7, and others. In addition, by using this approach, we identify a phosphorylation on A-kinase anchor protein-13 (AKAP13) at Ser2467 that dominantly controls its interaction with 14-3-3.
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Proteínas 14-3-3 , Mapas de Interação de Proteínas , Humanos , Proteínas 14-3-3/metabolismo , Sítios de Ligação , Proteínas Fetais/metabolismo , Aprendizado de Máquina , Proteína Quinase 7 Ativada por Mitógeno/metabolismo , Fosforilação , Proteínas Tirosina Quinases/metabolismo , Proteoma/metabolismo , Serina/metabolismo , Treonina/metabolismoRESUMO
Body mass is the primary determinant of an animal's energy requirements. At their optimum walking speed, large animals have lower mass-specific energy requirements for locomotion than small ones. In animals ranging in size from 0.8 g (roach) to 260 kg (zebu steer), the minimum cost of transport (COT(min)) decreases with increasing body size roughly as COT(min)âbody mass (M(b))(-0.316±0.023) (95% CI). Typically, the variation of COT(min) with body mass is weaker at the intraspecific level as a result of physiological and geometric similarity within closely related species. The interspecific relationship estimates that an adult elephant, with twice the body mass of a mid-sized elephant, should be able to move its body approximately 23% cheaper than the smaller elephant. We sought to determine whether adult Asian and sub-adult African elephants follow a single quasi-intraspecific relationship, and extend the interspecific relationship between COT(min) and body mass to 12-fold larger animals. Physiological and possibly geometric similarity between adult Asian elephants and sub-adult African elephants caused body mass to have a no effect on COT(min) (COT(min)âM(b)(0.007±0.455)). The COT(min) in elephants occurred at walking speeds between 1.3 and â¼1.5 m s(-1), and at Froude numbers between 0.10 and 0.24. The addition of adult Asian elephants to the interspecific relationship resulted in COT(min)âM (-0.277±0.046)(b). The quasi-intraspecific relationship between body mass and COT(min) among elephants caused the interspecific relationship to underestimate COT(min) in larger elephants.
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Elefantes/fisiologia , Marcha/fisiologia , Locomoção/fisiologia , Animais , Fenômenos Biomecânicos , Tamanho Corporal , Peso Corporal , Metabolismo Energético/fisiologia , Feminino , Consumo de Oxigênio , Reprodutibilidade dos Testes , CaminhadaRESUMO
Until 2006 the performance of confocal Raman spectroscopy depth profiling was typically described and modeled through the application of geometrical optics, including refraction at the surface, to explain the degree of resolution and the precise form of the depth profile obtained from transparent and semicrystalline materials. Consequently a range of techniques, physical and analytical, was suggested to avoid the errors thus encountered in order to improve the practice of Raman spectroscopy, if not the understanding of the underlying mechanisms. These approaches were completely unsuccessful in accounting for the precise form of the depth profile, the fact that spectra obtained from laminated samples always contain characteristic peaks from all materials present both well above and below the focal point and that spectra can be obtained when focused some 40 mum above the sample surface. This paper provides further evidence that the physical processes underlying Raman spectroscopy are better modeled and explained through the concept of an extended illuminated volume contributing to the final Raman spectrum and modeled through a photon scattering approach rather than a point focus ray optics approach. The power of this numerical model lies in its ability to incorporate, simultaneously, the effects of degree of refraction at the surface (whether using a dry or oil objective lens), the degree of attenuation due to scatter by the bulk of the material, the Raman scattering efficiency of the material, and surface roughness effects. Through this we are now able to explain why even removing surface aberration and refraction effects through the use of oil immersion objective lenses cannot reliably ensure that the material sampled is only that at or close to the point of focus of the laser. Furthermore we show that the precise form of the depth profile is affected by the degree of flatness of the surface of the sample. Perhaps surprisingly, we show that the degree of flatness of the material surface is, in fact, more important than obtaining a precise refractive index match between the immersion oil and the material when seeking a high-quality depth profile or Raman spectrum from within a transparent or semicrystalline material, contrary to accepted norms that samples for interrogation by Raman spectroscopy require little preparation.
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OBJECTIVE: R-spondin 2 (RSPO2) is required for lung morphogenesis, activates Wnt signaling, and is upregulated in idiopathic lung fibrosis. Our objective was to investigate whether RSPO2 is similarly important in homeostasis of the adult lung. While investigating the characteristics of bronchoalveolar lavage in RSPO2-deficient (RSPO2-/-) mice, we observed unexpected changes in neutrophil homeostasis and vascular permeability when compared to control (RSPO2+/+) mice at baseline. Here we quantify these observations to explore how tonic RSPO2 expression impacts lung homeostasis. RESULTS: Quantitative PCR (qPCR) analysis demonstrated significantly elevated myeloperoxidase (MPO) expression in bronchoalveolar lavage fluid (BALF) cells from RSPO2-/- mice. Likewise, immunocytochemical (ICC) analysis demonstrated significantly more MPO+ cells in BALF from RSPO2-/- mice compared to controls, confirming the increase of infiltrated neutrophils. We then assessed lung permeability/barrier disruption via Fluorescein Isothiocyanate (FITC)-dextran instillation and found a significantly higher dextran concentration in the plasma of RSPO2-/- mice compared to identically treated RSPO2+/+ mice. These data demonstrate that RSPO2 may be crucial for blood-gas barrier integrity and can limit neutrophil migration from circulation into alveolar spaces associated with increased lung permeability and/or barrier disruption. This study indicates that additional research is needed to evaluate RSPO2 in scenarios characterized by pulmonary edema or neutrophilia.
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Neutrófilos/metabolismo , Alvéolos Pulmonares/metabolismo , Trombospondinas/metabolismo , Animais , Líquido da Lavagem Broncoalveolar , Feminino , Deleção de Genes , Masculino , Camundongos Endogâmicos C57BL , Permeabilidade , Trombospondinas/deficiênciaRESUMO
The gravity field of a small body provides insight into its internal mass distribution. We used two approaches to measure the gravity field of the rubble-pile asteroid (101955) Bennu: (i) tracking and modeling the spacecraft in orbit about the asteroid and (ii) tracking and modeling pebble-sized particles naturally ejected from Bennu's surface into sustained orbits. These approaches yield statistically consistent results up to degree and order 3, with the particle-based field being statistically significant up to degree and order 9. Comparisons with a constant-density shape model show that Bennu has a heterogeneous mass distribution. These deviations can be modeled with lower densities at Bennu's equatorial bulge and center. The lower-density equator is consistent with recent migration and redistribution of material. The lower-density center is consistent with a past period of rapid rotation, either from a previous Yarkovsky-O'Keefe-Radzievskii-Paddack cycle or arising during Bennu's accretion following the disruption of its parent body.
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Sunspots, flares, and the myriad time-varying "events" observable in the Sun-the only star whose surface we can examine in detail-are testimony that the Sun is a magnetically variable or active star. Its magnetic field, carried into interplanetary space by the solar wind, produces observable changes in Earth's magnetosphere and variations in the flux of galactic cosmic-ray particles incident upon Earth's upper atmosphere. Centuries of observation have enabled solar scientists to recognize that the Sun's magnetism exists and varies in a globally organized pattern that is somehow coupled to the Sun's rotation. Within the past decade O. C. Wilson demonstrated that analogs of solar activity exist and can be studied in many other dwarf stars. From the continuing study, knowledge of the precise rates of rotation of the stars under investigation is being gained for the first time. The results are expected to increase our understanding of the origin of solar activity and stellar activity in general.
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AIMS: To investigate antifungal activity produced by lactic acid bacteria (LAB) isolated from malted cereals and to determine if such LAB have the capacity to prevent fungal growth in a particular food model system. METHODS AND RESULTS: The effect of pH, temperature and carbon source on production of antifungal activity by four LAB was determined. Pediococcus pentosaceus was used to conduct a trial to determine if it is feasible to eliminate Penicillium expansum, the mould responsible for apple rot, using an apple model. Penicillium expansum was incapable of growth during the trial on apple-based agar plates inoculated with the antifungal-producing culture, whereas the mould did grow on apple plates inoculated with an LAB possessing no antifungal activity. CONCLUSION: Partial characterization of the antifungal compounds indicates that their activity is likely to be because of production of antifungal peptides. The trial conducted showed that the antifungal culture has the ability to prevent growth of the mould involved in apple spoilage, using apples as a model. SIGNIFICANCE AND IMPACT OF THE STUDY: The ability of an LAB to prevent growth of Pen. expansum using the apple model suggests that these antifungal LAB have potential applications in the food industry to prevent fungal spoilage of food.
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Antifúngicos/metabolismo , Microbiologia de Alimentos , Lactobacillaceae/metabolismo , Malus/microbiologia , Antifúngicos/farmacologia , Reatores Biológicos/microbiologia , Grão Comestível/microbiologia , Conservação de Alimentos , Concentração de Íons de Hidrogênio , Lactobacillaceae/isolamento & purificação , Testes de Sensibilidade Microbiana , Penicillium/efeitos dos fármacos , TemperaturaRESUMO
BACKGROUND: Continuing advances in the understanding of Alzheimer's disease progression have inspired development of disease-modifying therapeutics intended for use in preclinical populations. However, identification of clinically meaningful cognitive and functional outcomes for individuals who are, by definition, asymptomatic remains a significant challenge. Clinical trials for prevention and early intervention require measures with increased sensitivity to subtle deficits in instrumental activities of daily living (IADL) that comprise the first functional declines in prodromal disease. Validation of potential endpoints is required to ensure measure sensitivity and reliability in the populations of interest. OBJECTIVES: The present research validates use of the Virtual Reality Functional Capacity Assessment Tool (VRFCAT) for performance-based assessment of IADL functioning in older adults (age 55+) with subjective cognitive decline. DESIGN: Cross-sectional validation study. SETTING: All participants were evaluated on-site at NeuroCog Trials, Durham, NC, USA. PARTICIPANTS: Participants included 245 healthy younger adults ages 20-54 (131 female), 247 healthy older adults ages 55-91 (151 female) and 61 older adults with subjective cognitive decline (SCD) ages 56-97 (45 female). MEASURES: Virtual Reality Functional Capacity Assessment Tool; Brief Assessment of Cognition App; Alzheimer's Disease Cooperative Study Prevention Instrument Project - Mail-In Cognitive Function Screening Instrument; Alzheimer's Disease Cooperative Study Instrumental Activities of Daily Living - Prevention Instrument, University of California, San Diego Performance-Based Skills Assessment - Validation of Intermediate Measures; Montreal Cognitive Assessment; Trail Making Test- Part B. RESULTS: Participants with SCD performed significantly worse than age-matched normative controls on all VRFCAT endpoints, including total completion time, errors and forced progressions (p≤0001 for all, after Bonferonni correction). Consistent with prior findings, both groups performed significantly worse than healthy younger adults (age 20-54). Participants with SCD also performed significantly worse than controls on objective cognitive measures. VRFCAT performance was strongly correlated with cognitive performance. In the SCD group, VRFCAT performance was strongly correlated with cognitive performance across nearly all tests with significant correlation coefficients ranging from 0.3 to 0.7; VRFCAT summary measures all had correlations greater than r=0.5 with MoCA performance and BAC App Verbal Memory (p<0.01 for all). CONCLUSIONS: Findings suggest the VRFCAT provides a sensitive tool for evaluation of IADL functioning in individuals with subjective cognitive decline. Strong correlations with cognition across groups suggest the VRFCAT may be uniquely suited for clinical trials in preclinical AD, as well as longitudinal investigations of the relationship between cognition and function.
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Atividades Cotidianas , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/psicologia , Testes Neuropsicológicos , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Realidade Virtual , Adulto JovemRESUMO
Essentials Endothelial activation initiates multiple processes, including hemostasis and inflammation. The molecules that contribute to these processes are co-stored in secretory granules. How can the cells control release of granule content to allow differentiated responses? Selected agonists recruit an exocytosis-linked actin ring to boost release of a subset of cargo. SUMMARY: Background Endothelial cells harbor specialized storage organelles, Weibel-Palade bodies (WPBs). Exocytosis of WPB content into the vascular lumen initiates primary hemostasis, mediated by von Willebrand factor (VWF), and inflammation, mediated by several proteins including P-selectin. During full fusion, secretion of this large hemostatic protein and smaller pro-inflammatory proteins are thought to be inextricably linked. Objective To determine if secretagogue-dependent differential release of WPB cargo occurs, and whether this is mediated by the formation of an actomyosin ring during exocytosis. Methods We used VWF string analysis, leukocyte rolling assays, ELISA, spinning disk confocal microscopy, high-throughput confocal microscopy and inhibitor and siRNA treatments to demonstrate the existence of cellular machinery that allows differential release of WPB cargo proteins. Results Inhibition of the actomyosin ring differentially effects two processes regulated by WPB exocytosis; it perturbs VWF string formation but has no effect on leukocyte rolling. The efficiency of ring recruitment correlates with VWF release; the ratio of release of VWF to small cargoes decreases when ring recruitment is inhibited. The recruitment of the actin ring is time dependent (fusion events occurring directly after stimulation are less likely to initiate hemostasis than later events) and is activated by protein kinase C (PKC) isoforms. Conclusions Secretagogues differentially recruit the actomyosin ring, thus demonstrating one mechanism by which the prothrombotic effect of endothelial activation can be modulated. This potentially limits thrombosis whilst permitting a normal inflammatory response. These results have implications for the assessment of WPB fusion, cargo-content release and the treatment of patients with von Willebrand disease.
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Actomiosina/fisiologia , Células Endoteliais/metabolismo , Exocitose/efeitos dos fármacos , Hemostasia/fisiologia , Inflamação/fisiopatologia , Corpos de Weibel-Palade/metabolismo , 1-Metil-3-Isobutilxantina/farmacologia , Actomiosina/antagonistas & inibidores , Actomiosina/química , Citocalasinas/farmacologia , Células Endoteliais/efeitos dos fármacos , Epinefrina/farmacologia , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Histamina/farmacologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Migração e Rolagem de Leucócitos/fisiologia , Selectina-P/genética , Selectina-P/fisiologia , Conformação Proteica , Interferência de RNA , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/farmacologia , Acetato de Tetradecanoilforbol/farmacologia , Corpos de Weibel-Palade/efeitos dos fármacos , Fator de von Willebrand/fisiologiaRESUMO
The ABC1 transporter was identified as the defect in Tangier disease by a combined strategy of gene expression microarray analysis, genetic mapping, and biochemical studies. Patients with Tangier disease have a defect in cellular cholesterol removal, which results in near zero plasma levels of HDL and in massive tissue deposition of cholesteryl esters. Blocking the expression or activity of ABC1 reduces apolipoprotein-mediated lipid efflux from cultured cells, and increasing expression of ABC1 enhances it. ABC1 expression is induced by cholesterol loading and cAMP treatment and is reduced upon subsequent cholesterol removal by apolipoproteins. The protein is incorporated into the plasma membrane in proportion to its level of expression. Different mutations were detected in the ABC1 gene of 3 unrelated patients. Thus, ABC1 has the properties of a key protein in the cellular lipid removal pathway, as emphasized by the consequences of its defect in patients with Tangier disease.
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Transportadores de Cassetes de Ligação de ATP/fisiologia , Apolipoproteínas/fisiologia , Glicoproteínas/fisiologia , Metabolismo dos Lipídeos , Doença de Tangier/genética , Transportador 1 de Cassete de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Adolescente , Animais , Células Cultivadas , Regulação da Expressão Gênica , Glicoproteínas/genética , Humanos , Masculino , Camundongos , Mutação , Doença de Tangier/complicaçõesRESUMO
Compromised function of an epiphyseal plate caused by trauma, tumor, infection, or congenital malformation can result in significant musculoskeletal deformity. Techniques used to correct or minimize the extent of these deformities include autogenous or allogeneic cancellous bone grafts, nonvascularized cortical allografts, vascularized bone and composite tissue transfers, and distraction osteogenesis. These solutions are not ideal for children because they do not adequately address the actively growing nature of the extremity. Microvascular techniques have enabled the experimental transplantation of vascularized epiphyseal plates with high levels of postoperative viability and subsequent growth and offer a potential advantage over conventional treatments.
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Doenças Ósseas/cirurgia , Transplante Ósseo/métodos , Lâmina de Crescimento/irrigação sanguínea , Lâmina de Crescimento/transplante , Animais , Humanos , Tíbia/irrigação sanguínea , Tíbia/transplante , Transplante Homólogo , Resultado do TratamentoRESUMO
BACKGROUND: Pneumonia is estimated to cause 2 million deaths every year in children. Streptococcus pneumoniae is the most important cause of severe pneumonia. We aimed to assess the efficacy of a nine-valent pneumococcal conjugate vaccine in children. METHODS: We undertook a randomised, placebo-controlled, double-blind trial in eastern Gambia. Children age 6-51 weeks were randomly allocated three doses of either pneumococcal conjugate vaccine (n=8718) or placebo (8719), with intervals of at least 25 days between doses. Our primary outcome was first episode of radiological pneumonia. Secondary endpoints were clinical or severe clinical pneumonia, invasive pneumococcal disease, and all-cause admissions. Analyses were per protocol and intention to treat. FINDINGS: 529 children assigned vaccine and 568 allocated placebo were not included in the per-protocol analysis. Results of per-protocol and intention-to-treat analyses were similar. By per-protocol analysis, 333 of 8189 children given vaccine had an episode of radiological pneumonia compared with 513 of 8151 who received placebo. Pneumococcal vaccine efficacy was 37% (95% CI 27-45) against first episode of radiological pneumonia. First episodes of clinical pneumonia were reduced overall by 7% (95% CI 1-12). Efficacy of the conjugate vaccine was 77% (51-90) against invasive pneumococcal disease caused by vaccine serotypes, 50% (21-69) against disease caused by all serotypes, and 15% (7-21) against all-cause admissions. We also found an efficacy of 16% (3-28) against mortality. 110 serious adverse events arose in children given the pneumococcal vaccine compared with 131 in those who received placebo. INTERPRETATION: In this rural African setting, pneumococcal conjugate vaccine has high efficacy against radiological pneumonia and invasive pneumococcal disease, and can substantially reduce admissions and improve child survival. Pneumococcal conjugate vaccines should be made available to African infants.
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Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/administração & dosagem , Pneumonia Pneumocócica/prevenção & controle , Pré-Escolar , Feminino , Gâmbia/epidemiologia , Humanos , Esquemas de Imunização , Incidência , Lactente , Masculino , Infecções Pneumocócicas/diagnóstico , Infecções Pneumocócicas/epidemiologia , Vacinas Pneumocócicas/efeitos adversos , Pneumonia Pneumocócica/diagnóstico , Pneumonia Pneumocócica/epidemiologia , Vacinas ConjugadasRESUMO
Exposure to topoisomerase II inhibitors is linked to the generation of leukemia involving translocations of the MLL gene, normally restricted to an 8.3 kbp tract, the breakpoint cluster region (BCR). Using an in vitro assay, apoptotic activators, including radiation and anti-CD95 antibody, trigger site-specific cleavage adjacent to exon 12 within the MLL BCR and promote translocation of the MLL gene in cells that can survive. To explore the mechanism of cleavage and rearrangement in more detail, the entire MLL BCR was placed into the pREP4 episomal vector and transfected into human lymphoblastoid TK6 cells. Episomes containing either the MLL BCR, or deletion constructs of 367 bp or larger, were cleaved at the same position as genomic MLL after exposure to apoptotic stimuli. Further analysis of sequence motifs surrounding the cleaved region of MLL showed the presence of both a predicted nuclear matrix attachment sequence and a potential strong binding site for topoisomerase II, flanking the site of cleavage. Inactivation of topoisomerase II by the catalytic inhibitor merbarone did not inhibit MLL cleavage, suggesting that the initial cleavage step for MLL rearrangement is not mediated by topoisomerase II.