RESUMO
Marine traffic is increasing globally yet collisions with endangered megafauna such as whales, sea turtles, and planktivorous sharks go largely undetected or unreported. Collisions leading to mortality can have population-level consequences for endangered species. Hence, identifying simultaneous space use of megafauna and shipping throughout ranges may reveal as-yet-unknown spatial targets requiring conservation. However, global studies tracking megafauna and shipping occurrences are lacking. Here we combine satellite-tracked movements of the whale shark, Rhincodon typus, and vessel activity to show that 92% of sharks' horizontal space use and nearly 50% of vertical space use overlap with persistent large vessel (>300 gross tons) traffic. Collision-risk estimates correlated with reported whale shark mortality from ship strikes, indicating higher mortality in areas with greatest overlap. Hotspots of potential collision risk were evident in all major oceans, predominantly from overlap with cargo and tanker vessels, and were concentrated in gulf regions, where dense traffic co-occurred with seasonal shark movements. Nearly a third of whale shark hotspots overlapped with the highest collision-risk areas, with the last known locations of tracked sharks coinciding with busier shipping routes more often than expected. Depth-recording tags provided evidence for sinking, likely dead, whale sharks, suggesting substantial "cryptic" lethal ship strikes are possible, which could explain why whale shark population declines continue despite international protection and low fishing-induced mortality. Mitigation measures to reduce ship-strike risk should be considered to conserve this species and other ocean giants that are likely experiencing similar impacts from growing global vessel traffic.
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Tubarões , Animais , Espécies em Perigo de Extinção , Plâncton , NaviosRESUMO
OBJECTIVE: The lack of consensus and specific guidelines, and the introduction of new treatments in thrombocytopenia management in liver cirrhosis patients, required a series of recommendations by experts to improve knowledge on this disease. This study's aim was to improve the knowledge around thrombocytopenia in liver cirrhosis patients, in order to contribute to the generation of future evidence to improve the management of this disease. PATIENTS AND METHODS: A modified version of the RAND/UCLA appropriateness method was used. The scientific committee, a multidisciplinary team of 7 experts in managing thrombocytopenia in liver cirrhosis patients, identified the expert panel, and participated in elaborating the questionnaire. Thirty experts from different Spanish institutions were invited to answer a 48-item questionnaire covering 6 areas on a nine-point Likert scale. Two rounds were voted. The consensus was obtained if >77.7% of panelists reached agreement or disagreement. RESULTS: A total of 48 statements were developed by the scientific committee and then voted by the experts, resulting in 28 defined as appropriate and completely necessary, relating to evidence generation (10), care circuit, (8), hemorrhagic risk assessment, decision-making and diagnostic tests (14), professionals' role and multidisciplinary coordination (9) and patient education (7). CONCLUSIONS: This is the first consensus in Spain on the management of thrombocytopenia in liver cirrhosis patients. Experts indicated several recommendations to be carried out in different areas that could help physicians make better decisions in their clinical practice.
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Cirrose Hepática , Trombocitopenia , Humanos , Cirrose Hepática/complicações , Consenso , Trombocitopenia/complicações , Trombocitopenia/terapia , Espanha , Inquéritos e QuestionáriosRESUMO
OBJECTIVES: To describe the association between chronic noncommunicable diseases and age with hospitalization, death and severe clinical outcomes for COVID-19 in confirmed cases within the mexican population, comparing the first three epidemiological waves of the pandemic in Mexico. DESIGN: We performed an analysis using Mexico's Government Epidemiological Surveillance System database for COVID-19. EMPLACEMENT: Mexico's Epidemiological Surveillance System for Respiratory Diseases. PARTICIPANTS: Mexican population confirmed with SARS-CoV-2 registered on Mexico's Epidemiological Surveillance System for Respiratory Diseases. PRIMARY MEASUREMENTS: The analysed severe outcomes were hospitalization, pneumonia, use of mechanical ventilation, intensive care unit admission and death. The association (odds ratio) between the outcomes and clinical variables was evaluated, comparing the three epidemiological waves in Mexico. RESULTS: Age over 65 is associated with a higher ratio of hospitalization and pneumonia, independent of the effect of chronic comorbidities. There is an interaction between age and obesity, which is associated with hospitalization, pneumonia and highly associated with death. These findings were consistent throughout the three epidemiological waves. CONCLUSION: Obesity, COPD and diabetes in interaction with age, are associated with worse clinical outcomes and, more importantly, death in patients with COVID-19.
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COVID-19 , Humanos , COVID-19/epidemiologia , COVID-19/terapia , SARS-CoV-2 , México/epidemiologia , Fatores de Risco , Obesidade/complicações , Obesidade/epidemiologia , Atenção Primária à SaúdeRESUMO
INTRODUCTION: Type 2N von Willebrand disease (VWD) is characterized by a decreased affinity of von Willebrand factor (VWF) for factor VIII (FVIII). Abnormal binding of FVIII to VWF (VWF:FVIIIB), results in low FVIII plasma levels, which can lead to a misdiagnosis of mild haemophilia A. Accurate diagnosis of type 2N VWD is essential for appropriate genetic counselling and therapy. This disease can be distinguished from haemophilia A by in vitro assays (measurement VWF:FVIIIB activity) and/or genetic analysis. AIM: To identify the current challenges in the diagnosis and treatment of this type of VWD and provide an in-depth description of the phenotypes and mutations identified. RESULTS: Twenty-eight patients had at least one type 2N mutation, and 13 of these had a type 2N mutation combined with other variations. Three type 2N mutations were detected: p.Arg816Trp, p.Arg854Gln, and p.Arg763Ser. Two of these are the most frequently described mutations worldwide. This mutational spectrum differs from the broad spectrum seen in neighbouring France, where at least eight distinct 2N mutations have been found. In the PCM-EVW-ES cohort, 11 asymptomatic type 2N carriers with borderline FVIII plasma levels would probably have been excluded if the evaluation had been based on clinical and laboratory data only. Likewise, three patients with a severe phenotype would have been classified as homozygous for a 2N mutation if only the phenotype study had been performed. CONCLUSION: The high detection yield and affordability of next-generation sequencing support the use of this technology as a first-line diagnostic tool in this setting.
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Hemofilia A , Doença de von Willebrand Tipo 2 , Doenças de von Willebrand , Fator de von Willebrand/genética , Fator VIII/genética , Heterozigoto , Homozigoto , Humanos , Doença de von Willebrand Tipo 2/diagnóstico , Doença de von Willebrand Tipo 2/genéticaRESUMO
Collisions with buildings cause up to 1 billion bird fatalities annually in the United States and Canada. However, efforts to reduce collisions would benefit from studies conducted at large spatial scales across multiple study sites with standardized methods and consideration of species- and life-history-related variation and correlates of collisions. We addressed these research needs through coordinated collection of data on bird collisions with buildings at sites in the United States (35), Canada (3), and Mexico (2). We collected all carcasses and identified species. After removing records for unidentified carcasses, species lacking distribution-wide population estimates, and species with distributions overlapping fewer than 10 sites, we retained 269 carcasses of 64 species for analysis. We estimated collision vulnerability for 40 bird species with ≥2 fatalities based on their North American population abundance, distribution overlap in study sites, and sampling effort. Of 10 species we identified as most vulnerable to collisions, some have been identified previously (e.g., Black-throated Blue Warbler [Setophaga caerulescens]), whereas others emerged for the first time (e.g., White-breasted Nuthatch [Sitta carolinensis]), possibly because we used a more standardized sampling approach than past studies. Building size and glass area were positively associated with number of collisions for 5 of 8 species with enough observations to analyze independently. Vegetation around buildings influenced collisions for only 1 of those 8 species (Swainson's Thrush [Catharus ustulatus]). Life history predicted collisions; numbers of collisions were greatest for migratory, insectivorous, and woodland-inhabiting species. Our results provide new insight into the species most vulnerable to building collisions, making them potentially in greatest need of conservation attention to reduce collisions and into species- and life-history-related variation and correlates of building collisions, information that can help refine collision management.
Correlaciones de las Colisiones de Aves contra Edificios en Tres Países de América del Norte Resumen Las colisiones contra los edificios causan hasta mil millones de fatalidades de aves al año en los Estados Unidos y en Canadá. Sin embargo, los esfuerzos por reducir estas colisiones se beneficiarían con estudios realizados a grandes escalas espaciales en varios sitios de estudio con métodos estandarizados y considerando las variaciones relacionadas a la historia de vida y a la especie y las correlaciones de las colisiones. Abordamos estas necesidades de investigación por medio de una recolección coordinada de datos sobre las colisiones de aves contra edificios en los Estados Unidos (35), Canadá (3) y México (2). Recolectamos todos los cadáveres y los identificamos hasta especie. Después de retirar los registros de cadáveres no identificados, las especies sin estimaciones poblacionales a nivel distribución y las especies con distribuciones traslapadas en menos de diez sitios, nos quedamos con 269 cadáveres de 64 especies para el análisis. Estimamos la vulnerabilidad a colisiones para 40 especies con ≥2 fatalidades con base en la abundancia poblacional para América del Norte, el traslape de su distribución entre los sitios de estudio y el esfuerzo de muestreo. De las diez especies que identificamos como las más vulnerables a las colisiones, algunas han sido identificadas previamente (Setophaga caerulescens), y otras aparecieron por primera vez (Sitta carolinensis), posiblemente debido a que usamos una estrategia de muestreo más estandarizada que en los estudios previos. El tamaño del edificio y el área del vidrio estuvieron asociados positivamente con el número de colisiones para cinco de ocho especies con suficientes observaciones para ser analizadas independientemente. La vegetación alrededor de los edificios influyó sobre las colisiones solamente para una de esas ocho especies Catharus ustulatus). Las historias de vida pronosticaron las colisiones; el número de colisiones fue mayor para las especies migratorias, insectívoras y aquellas que habitan en las zonas boscosas. Nuestros resultados proporcionan una nueva perspectiva hacia las especies más vulnerables a las colisiones contra edificios, lo que las pone en una necesidad potencialmente mayor de atención conservacionista para reducir estas colisiones y de estudio de las variaciones relacionadas con la especie y la historia de vida y las correlaciones de las colisiones contra edificios, información que puede ayudar a refinar el manejo de colisiones.
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Conservação dos Recursos Naturais , Aves Canoras , Animais , Canadá , México , América do Norte , Estados UnidosRESUMO
Readthrough therapy relies on the use of small molecules that enable premature termination codons in mRNA open reading frames to be misinterpreted by the translation machinery, thus allowing the generation of full-length, potentially functional proteins from mRNA carrying nonsense mutations. In patients with hemophilia A, nonsense mutations potentially sensitive to readthrough agents represent approximately 16% of the point mutations. The aim of this study was to measure the readthrough effect of different compounds and to analyze the influence of premature termination codon context in selected nonsense mutations causing hemophilia A. To this end, primary fibroblasts from three patients with hemophilia A caused by nonsense mutations (p.W1586X, p.Q1636X and p.R1960X) and Chinese hamster ovary (CHO) cells transfected with 12 different plasmids encoding mutated F8 (p.Q462X, p.Q1705X, p.Q1764X, p.W274X, p.W1726X, p.W2015X, p.W2131X, p.R1715X, p.R1822X, p.R1960X, p.R2071X and p.R2228X) were treated with gentamicin, geneticin, PTC124, RTC13 or RTC14. Responses were assessed by analyzing not only F8 mRNA expression and FVIII biosynthesis (FVIII antigen by ELISA, western blot and immunofluorescence) but also the FVIII activity (by chromogenic assay). In the patients' fibroblasts, readthrough agents neither stabilized F8 mRNA nor increased FVIII protein or activity to detectable levels. In CHO cells, only in five of the 12 F8 variants, readthrough treatment increased both FVIII antigen and activity levels, which was associated with a reduction in intracellular accumulation of truncated forms and an increase in full-length proteins. These results provide experimental evidence of genetic context dependence of nonsense suppression by readthrough agents and of factors predicting responsiveness.
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Códon sem Sentido , Hemofilia A , Animais , Células CHO , Cricetinae , Cricetulus , Hemofilia A/tratamento farmacológico , Hemofilia A/genética , Humanos , RNA Mensageiro/genéticaRESUMO
Whale sharks (Rhincodon typus) - the largest extant fish species - reside in tropical environments, making them an exception to the general rule that animal size increases with latitude. How this largest fish thrives in tropical environments that promote high metabolism but support less robust zooplankton communities has not been sufficiently explained. We used open-source inertial measurement units (IMU) to log 397â h of whale shark behavior in Yucatán, Mexico, at a site of both active feeding and intense wildlife tourism. Here we show that the strategies employed by whale sharks to compensate for the increased drag of an open mouth are similar to ram feeders five orders of magnitude smaller and one order of magnitude larger. Presumed feeding constituted 20% of the total time budget of four sharks, with individual feeding bouts lasting up to 11 consecutive hours. Compared with normal, sub-surface swimming, three sharks increased their stroke rate and amplitude while surface feeding, while one shark that fed at depth did not demonstrate a greatly increased energetic cost. Additionally, based on time-depth budgets, we estimate that aerial surveys of shark populations should consider including a correction factor of 3 to account for the proportion of daylight hours that sharks are not visible at the surface. With foraging bouts generally lasting several hours, interruptions to foraging during critical feeding periods may represent substantial energetic costs to these endangered species, and this study presents baseline data from which management decisions affecting tourist interactions with whale sharks may be made.
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Tubarões , Natação , Animais , Espécies em Perigo de Extinção , Masculino , MéxicoRESUMO
OBJECTIVES: The Galápagos provides an important setting to investigate the health impacts of a new drinking water treatment plant (DWTP) in a limited resource environment. We examine how household perceptions and practices affect the relationship between water quality and infections before and after DWTP. METHODS: Ethnographic data and self-reported infections were collected from 121 mothers and 168 children ages 2 to 10 from Isla San Cristóbal. Household tap water samples were tested for levels of fecal contamination. Community level infection rates were estimated using discharge records from the Ministry of Public Health. The effects of the new DWTP and fecal contamination levels on infections were tested using logistic and Poisson models. RESULTS: Perceptions of water quality and household practices influenced exposures to contaminated tap water. We found minimal change in drinking water sources with 85% of mothers sampled before the DWTP and 83% sampled after using bottled water, while >85% from the pooled sample used tap water for cooking and hygiene practices. The DWTP opening was associated with lower odds of fecal contamination in tap water, reported urinary infections, and community level rates of urinary and gastrointestinal infections. The household practice of recently washing the cistern contributed to higher contamination levels after the DWTP opened. CONCLUSIONS: To ensure access to clean water, public health works need to consider how household perceptions and practices influence tap water use and quality, in addition to infrastructure improvements. Exposures to contaminated tap water contribute to the burden of infectious disease in environments with inadequate water infrastructure.
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Água Potável/análise , Gastroenteropatias/epidemiologia , Conhecimentos, Atitudes e Prática em Saúde , Infecções Urinárias/epidemiologia , Qualidade da Água , Adulto , Criança , Pré-Escolar , Equador/epidemiologia , Características da Família , Fezes/química , Feminino , Humanos , Higiene , Masculino , Características de Residência/estatística & dados numéricos , Adulto JovemRESUMO
Large studies in von Willebrand disease patients, including Spanish and Portuguese registries, led to the identification of >250 different mutations. It is a challenge to determine the pathogenic effect of potential splice site mutations on VWF mRNA. This study aimed to elucidate the true effects of 18 mutations on VWF mRNA processing, investigate the contribution of next-generation sequencing to in vivo mRNA study in von Willebrand disease, and compare the findings with in silico prediction. RNA extracted from patient platelets and leukocytes was amplified by RT-PCR and sequenced using Sanger and next generation sequencing techniques. Eight mutations affected VWF splicing: c.1533+1G>A, c.5664+2T>C and c.546G>A (p.=) prompted exon skipping; c.3223-7_3236dup and c.7082-2A>G resulted in activation of cryptic sites; c.3379+1G>A and c.7437G>A) demonstrated both molecular pathogenic mechanisms simultaneously; and the p.Cys370Tyr missense mutation generated two aberrant transcripts. Of note, the complete effect of three mutations was provided by next generation sequencing alone because of low expression of the aberrant transcripts. In the remaining 10 mutations, no effect was elucidated in the experiments. However, the differential findings obtained in platelets and leukocytes provided substantial evidence that four of these would have an effect on VWF levels. In this first report using next generation sequencing technology to unravel the effects of VWF mutations on splicing, the technique yielded valuable information. Our data bring to light the importance of studying the effect of synonymous and missense mutations on VWF splicing to improve the current knowledge of the molecular mechanisms behind von Willebrand disease. clinicaltrials.gov identifier:02869074.
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Inativação Gênica , Íntrons , Mutação de Sentido Incorreto , Splicing de RNA , Fator de von Willebrand/genética , Alelos , Sequência de Bases , Plaquetas/metabolismo , Biologia Computacional , Éxons , Feminino , Frequência do Gene , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Leucócitos/metabolismo , Masculino , Sítios de Splice de RNA , RNA Mensageiro/genética , Doenças de von Willebrand/genéticaRESUMO
AIM: The use of musculoskeletal ultrasound (MSK-US) following protocols for haemophilic arthropathy and the Haemophilia Early Arthropathy Detection with Ultrasound (HEAD-US) score can help standardize monitoring in haemophilia. This study evaluated the joint status (elbows, knees and ankles) of patients with haemophilia B (HB) in Spain using MSK-US and the HEAD-US score. METHODS: Haemophilia B patients ≥14 years old were included in this observational, multicentre, cross-sectional study, regardless of their clinical condition, HB severity and treatment received. Two blinded observers were involved in image acquisition and scoring in each centre. RESULTS: Eighty-two patients from 12 centres were enrolled: 27% mild HB, 23% moderate, 50% severe HB. Mean age was 38.9 ± 16.4 years, 60% were treated on demand (OD) and 40% were on prophylaxis. HEAD-US was zero in all joints in 28.6% OD patients and 36.4% on prophylaxis. Mean scores significantly worsened with HB severity, except for the left knee. Patients on primary and secondary prophylaxis had significantly better joint health vs OD patients in all joints, except the right ankle. Among OD patients, those with severe disease presented significantly worse scores in all HEAD-US items related to permanent damage. CONCLUSION: Joint status of HB patients in Spain is influenced by severity and treatment modality, related to the development of arthropathy, which appears prevalent in OD patients with severe HB. Routine assessment with an imaging tool such as ultrasound and HEAD-US system may help to improve joint health by personalizing and adjusting treatment in this population.
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Hemofilia B/patologia , Artropatias/diagnóstico , Articulações/diagnóstico por imagem , Sinovite/diagnóstico , Adolescente , Adulto , Estudos Transversais , Humanos , Artropatias/patologia , Modelos Logísticos , Pessoa de Meia-Idade , Razão de Chances , Índice de Gravidade de Doença , Espanha , Sinovite/patologia , Ultrassonografia , Adulto JovemRESUMO
Molecular diagnosis of patients with von Willebrand disease is pending in most populations due to the complexity and high cost of conventional molecular analyses. The need for molecular and clinical characterization of von Willebrand disease in Spain prompted the creation of a multicenter project (PCM-EVW-ES) that resulted in the largest prospective cohort study of patients with all types of von Willebrand disease. Molecular analysis of relevant regions of the VWF, including intronic and promoter regions, was achieved in the 556 individuals recruited via the development of a simple, innovative, relatively low-cost protocol based on microfluidic technology and next-generation sequencing. A total of 704 variants (237 different) were identified along VWF, 155 of which had not been previously recorded in the international mutation database. The potential pathogenic effect of these variants was assessed by in silico analysis. Furthermore, four short tandem repeats were analyzed in order to evaluate the ancestral origin of recurrent mutations. The outcome of genetic analysis allowed for the reclassification of 110 patients, identification of 37 asymptomatic carriers (important for genetic counseling) and re-inclusion of 43 patients previously excluded by phenotyping results. In total, 480 patients were definitively diagnosed. Candidate mutations were identified in all patients except 13 type 1 von Willebrand disease, yielding a high genotype-phenotype correlation. Our data reinforce the capital importance and usefulness of genetics in von Willebrand disease diagnostics. The progressive implementation of molecular study as the first-line test for routine diagnosis of this condition will lead to increasingly more personalized and effective care for this patient population.
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Doenças de von Willebrand/genética , Estudos de Associação Genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Mutação , Espanha/epidemiologia , Doenças de von Willebrand/diagnóstico , Fator de von Willebrand/genéticaRESUMO
BACKGROUND: The inflammatory process in aortic valvular stenosis persists after surgery to replace the valve in almost half of the patients. No association has been found to its persistence. The main objective of this study was to evaluate the inflammatory response in patients with aortic stenosis through the determination of several biomarkers in plasma measured before and after the valvular replacement and to seek an association with the type of prosthesis used. METHODS: This is an observational study with a follow up of 6 months in subjects with severe aortic stenosis. Seric concentrations of TNFa, IL-1, IL-6 and ICAM and echocardiographic variables were quantified previous to the surgery and a week and 6 months after it. A group of control subjects paired by age and gender was included. RESULTS: Seventy-nine subjects were studied of which 57% were male; the average age was of 59 (± 11.4) years. Previous to surgery, the concentration of cytokines was higher in patients than in control subjects. A biological prosthesis was implanted in 48 patients and a mechanical prosthesis in 31. Both, types of prosthesis have components made of titanium. The echocardiograms 1 week and 6 months after the surgery showed a decrease in the mean aortic gradient and an increase in the valvular area (p = 0.001). Half of the patients still showed high proinflammatory cytokine levels. There were no differences according to the type of prosthesis implanted after adjustments for demographic variables, comorbidities and echocardiographic data. CONCLUSIONS: The inflammatory response caused by both types of valvular prothesis at 6 months after implantation were similar. Both types of prosthesis are recommended, they had similarities in hemodynamic profiles registered with Doppler echocardiography. Age of the patient or the suitability use of anticoagulants determines the type of prosthesis to be used.
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Estenose da Valva Aórtica/cirurgia , Biomarcadores/sangue , Bioprótese , Próteses Valvulares Cardíacas , Inflamação/sangue , Estenose da Valva Aórtica/sangue , Ecocardiografia Doppler , Feminino , Seguimentos , Humanos , Inflamação/etiologia , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Período Pré-Operatório , Estudos Prospectivos , Desenho de Prótese , Fatores de TempoRESUMO
BACKGROUND AND AIM OF THE STUDY: The aim of this retrospective study was to evaluate the inflammatory response in patients with aortic and/or mitral prostheses, and to correlate the level of inflammatory markers with prosthesis functionality. METHODS: A total of 48 patients with biological or mechanical prostheses was included in the study, in which levels of tumor necrosis factor-alpha (TNFα), interleukin (IL)-1, -4, and -6, interferon-gamma (IFNγ), osteopontin (OPN), intercellular adhesion molecule (ICAM), vascular cell adhesion molecule (VCAM), endothelin-1 and C-reactive protein were analyzed. Functionality of the prosthesis was evaluated using transthoracic echocardiography at three years after surgery. RESULTS: The mean period from the date of surgery was seven years. High levels of IL-1 were found in patients with mechanical prostheses compared to those with bioprostheses (p = 0.04). Patients with aortic bioprostheses and stenosis had higher levels of OPN and endothelin-1, those with aortic mechanical prostheses with stenosis had increased levels of matrix metalloproteinase (MMP)-9, OPN and ICAM, and those with aortic mechanical leakage had increased levels of MMP-1 and endothelin-1. In mitral bioprostheses with leakage of endothelin-1, ICAM and MMP-9 levels were increased, while in mechanical prostheses with leakage there were increases of ICAM and endothelin-1. Tricuspid bioprostheses with double lesions had increased levels of OPN and endothelin-1. CONCLUSIONS: Valvular dysfunction was similar across the types of prosthesis material. IL-1 was increased in subjects with mechanical prostheses independently of dysfunction, while in biological prostheses there were increases in OPN and endothelin-1, and these were related to valvular dysfunction. Given that in the analysis of durability and functionality there were no significant differences between biological and mechanical prostheses, biological prostheses may represent the first treatment option in patients with low economic resources, the elderly, and even young patients.
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Valva Aórtica/cirurgia , Bioprótese , Implante de Prótese de Valva Cardíaca/efeitos adversos , Próteses Valvulares Cardíacas , Mediadores da Inflamação/imunologia , Inflamação/imunologia , Valva Mitral/cirurgia , Pericárdio/transplante , Idoso , Idoso de 80 Anos ou mais , Animais , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/imunologia , Valva Aórtica/fisiopatologia , Bovinos , Ecocardiografia Transesofagiana , Feminino , Xenoenxertos , Humanos , Inflamação/sangue , Inflamação/diagnóstico , Mediadores da Inflamação/sangue , Masculino , Pessoa de Meia-Idade , Valva Mitral/diagnóstico por imagem , Valva Mitral/imunologia , Valva Mitral/fisiopatologia , Pericárdio/diagnóstico por imagem , Pericárdio/imunologia , Desenho de Prótese , Falha de Prótese , Estudos Retrospectivos , Fatores de Tempo , Resultado do TratamentoRESUMO
Human genetic variation contributes to differences in susceptibility to HIV-1 infection. To search for novel host resistance factors, we performed a genome-wide association study (GWAS) in hemophilia patients highly exposed to potentially contaminated factor VIII infusions. Individuals with hemophilia A and a documented history of factor VIII infusions before the introduction of viral inactivation procedures (1979-1984) were recruited from 36 hemophilia treatment centers (HTCs), and their genome-wide genetic variants were compared with those from matched HIV-infected individuals. Homozygous carriers of known CCR5 resistance mutations were excluded. Single nucleotide polymorphisms (SNPs) and inferred copy number variants (CNVs) were tested using logistic regression. In addition, we performed a pathway enrichment analysis, a heritability analysis, and a search for epistatic interactions with CCR5 Δ32 heterozygosity. A total of 560 HIV-uninfected cases were recruited: 36 (6.4%) were homozygous for CCR5 Δ32 or m303. After quality control and SNP imputation, we tested 1 081 435 SNPs and 3686 CNVs for association with HIV-1 serostatus in 431 cases and 765 HIV-infected controls. No SNP or CNV reached genome-wide significance. The additional analyses did not reveal any strong genetic effect. Highly exposed, yet uninfected hemophiliacs form an ideal study group to investigate host resistance factors. Using a genome-wide approach, we did not detect any significant associations between SNPs and HIV-1 susceptibility, indicating that common genetic variants of major effect are unlikely to explain the observed resistance phenotype in this population.
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Resistência à Doença/genética , Estudo de Associação Genômica Ampla , Infecções por HIV/genética , Hemofilia A/genética , Adulto , Variações do Número de Cópias de DNA , Epistasia Genética , Fator VIII/uso terapêutico , Feminino , Deleção de Genes , Predisposição Genética para Doença , Soropositividade para HIV/genética , Heterozigoto , Homozigoto , Humanos , Modelos Logísticos , Masculino , Metanálise como Assunto , Pessoa de Meia-Idade , Fenótipo , Polimorfismo de Nucleotídeo Único , Estudos Prospectivos , Receptores CCR5/genética , Receptores CCR5/metabolismoRESUMO
The purpose of this work is reviewing some reduction results to deal with systems of nonautonomous ordinary differential equations with two time scales. They could be included among the so-called approximate aggregation methods. The existence of different time scales in a system, together with some long-term features, are used to build up a simpler system governed by a lesser number of state variables. The asymptotic behavior of the latter system is then used to describe the asymptotic behaviour of the former one. The reduction results are stated in two particular but important cases: periodic systems and asymptotically autonomous systems. The reduction results are illustrated with the help of simple spatial SIS epidemic models including either periodic or asymptotically autonomous terms.
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Modelos Teóricos , Dinâmica PopulacionalRESUMO
The expansion of the world's merchant fleet poses a great threat to the ocean's biodiversity. Collisions between ships and marine megafauna can have population-level consequences for vulnerable species. The Endangered whale shark (Rhincodon typus) shares a circumglobal distribution with this expanding fleet and tracking of movement pathways has shown that large vessel collisions pose a major threat to the species. However, it is not yet known whether they are also at risk within aggregation sites, where up to 400 individuals can gather to feed on seasonal bursts of planktonic productivity. These "constellation" sites are of significant ecological, socio-economic and cultural value. Here, through expert elicitation, we gathered information from most known constellation sites for this species across the world (>50 constellations and >13,000 individual whale sharks). We defined the spatial boundaries of these sites and their overlap with shipping traffic. Sites were then ranked based on relative levels of potential collision danger posed to whale sharks in the area. Our results showed that researchers and resource managers may underestimate the threat posed by large ship collisions due to a lack of direct evidence, such as injuries or witness accounts, which are available for other, sub-lethal threat categories. We found that constellations in the Arabian Sea and adjacent waters, the Gulf of Mexico, the Gulf of California, and Southeast and East Asia, had the greatest level of collision threat. We also identified 39 sites where peaks in shipping activity coincided with peak seasonal occurrences of whale sharks, sometimes across several months. Simulated collision mitigation options estimated potentially minimal impact to industry, as most whale shark core habitat areas were small. Given the threat posed by vessel collisions, a coordinated, multi-national approach to mitigation is needed within priority whale shark habitats to ensure collision protection for the species.
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Conservação dos Recursos Naturais , Tubarões , Navios , Animais , Tubarões/fisiologia , Espécies em Perigo de Extinção , Monitoramento AmbientalRESUMO
Understanding the mechanisms of coexistence and niche partitioning in plant communities is a central question in ecology. Current theories of forest dynamics range between the so-called neutral theories which assume functional equivalence among coexisting species to forest simulators that explain species assemblages as the result of tradeoffs in species individual strategies at several ontogenetic stages. Progress in these questions has been hindered by the inherent difficulties of developing analytical size-structured models of stand dynamics. This precludes examination of the relative importance of each mechanism on tree coexistence. In previous simulation and analytical studies emphasis has been given to interspecific differences at the sapling stage, and less so to interspecific variation in seedling recruitment. In this study we develop a partial differential equation model of stand dynamics in which competition takes place at the recruitment stage. Species differ in their size-dependent growth rates and constant mortality rates. Recruitment is described as proportional to the basal area of conspecifics, to account for fecundity and seed supply per unit of basal area, and is corrected with a decreasing function of species specific basal area to account for competition. We first analyze conditions for population persistence in monospecific stands and second we investigate conditions of coexistence for two species. In the monospecific case we found a stationary stand structure based on an inequality between mortality rate and seed supply. In turn, intra-specific competition does not play any role on the asymptotic extinction or population persistence. In the two-species case we found that coexistence can be attained when the reciprocal negative effect on recruitment follows a given relation with respect to intraspecific competition. Specifically a tradeoff between recruitment potential (i.e. shade tolerance or predation avoidance) and fecundity or growth rate. This is to our knowledge the first study that describes coexistence mechanisms in an analytical size-structured model in terms of competitive differences at the regeneration state.
Assuntos
Ecossistema , Modelos Biológicos , Fenômenos Fisiológicos Vegetais , Plantas , Especificidade da EspécieRESUMO
Background: Obesity, a public health problem, is a state of metainflammation that influences the development of chronic degenerative diseases, particularly in patients with severe obesity. Objective: The objective of this study was to evidence immunometabolic differences in patients with different degrees of obesity, including severe obesity, by determining correlations between lymphocyte subpopulations and metabolic, body composition, and clinical variables. Methods: Peripheral blood immune cells (CD4+, CD8+ memory and effector T lymphocytes) were analyzed, and measures of body composition, blood pressure, and biochemical composition (glucose, glycated hemoglobin (HbA1c), insulin, C-reactive protein (CRP), and the lipid profile) were carried out in patients with different degrees of obesity. Results: The patients were classified according to total body fat (TBF) percentage as normal body fat, class 1 and 2 obesity, class 3 obesity, and class 4 obesity. The greater the TBF percentage, the more pronounced the differences in body composition (such as a decrease in the fat-free mass (FFM) that is defined as sarcopenic obesity) and the immunometabolic profile. There was an increase of CD3+ T lymphocytes (mainly CD4+, CD4+CD62-, and CD8+CD45RO+ T lymphocytes) and an increase in the TBF percentage (severity of obesity). Conclusions: The correlations between lymphocyte subpopulations and metabolic, body composition, and clinical variables demonstrated the existence of a chronic, low-intensity inflammatory process in obesity. Therefore, measuring the immunometabolic profile by means of lymphocyte subpopulations in patients with severe obesity could be useful to determine the severity of the disease and the increased risk of presenting obesity-associated chronic degenerative diseases.
Assuntos
Linfócitos T CD4-Positivos , Obesidade Mórbida , Humanos , Obesidade Mórbida/metabolismo , Subpopulações de Linfócitos , Linfócitos T CD8-Positivos , Obesidade/metabolismoRESUMO
Genetic analysis of von Willebrand disease by von Willebrand factor gene sequencing has not yet become routine practice. Nevertheless, the prospects for molecular diagnosis have changed dramatically in recent years with the unveiling of next-generation sequencing platforms. With the goal of applying this technology to von Willebrand disease, we designed a strategy for von Willebrand factor gene enrichment and multiplexing based on short polymerase chain reactions. Forty patients were simultaneously analyzed enabling the identification of 43 mutations, including 36 substitutions, 2 intronic splice site mutations, 2 indels, and 3 deletions. By pooling patient genomic DNA before polymerase chain reaction enrichment, indexing samples with barcode tags, and re-sequencing on the next-generation sequencing instrument, at least 350 patients and relatives per run can be simultaneously analyzed in a fast, inexpensive manner. This is one of the first reports in which this technology has been shown to be feasible for large-scale mutation screening by single gene re-sequencing.