RESUMO
Age-related macular degeneration (AMD) is a major cause of vision loss among the elderly in the Western world. Genetic variants in the complement factor H (CFH) gene are associated with AMD, but the functional consequences of many of these variants are currently unknown. In this study, we aimed to determine the effect of 64 rare and low-frequency variants in the CFH gene on systemic levels of factor H (FH) and complement activation marker C3bBbP using plasma samples of 252 carriers and 159 non-carriers. Individuals carrying a heterozygous nonsense, frameshift or missense variant in CFH presented with significantly decreased FH levels and significantly increased C3bBbP levels in plasma compared to non-carrier controls. FH and C3bBbP plasma levels were relatively stable over time in samples collected during follow-up visits. Decreased FH and increased C3bBbP concentrations were observed in carriers compared to non-carriers of CFH variants among different AMD stages, with the exception of C3bBbP levels in advanced AMD stages, which were equally high in carriers and non-carriers. In AMD families, FH levels were decreased in carriers compared to non-carriers, but C3bBbP levels did not differ. Rare variants in the CFH gene can lead to reduced FH levels or reduced FH function as measured by increased C3bBbP levels. The effects of individual variants in the CFH gene reported in this study will improve the interpretation of rare and low-frequency variants observed in AMD patients in clinical practice.
Assuntos
Degeneração Macular , Polimorfismo de Nucleotídeo Único , Idoso , Fator H do Complemento/genética , Proteínas do Sistema Complemento/genética , Heterozigoto , Humanos , Degeneração Macular/genética , Mutação de Sentido IncorretoRESUMO
BACKGROUND: Common genetic variants of the enzymes and efflux pump involved in tacrolimus disposition have been associated with calcineurin inhibitor nephrotoxicity, but their importance is unclear because of the multifactorial background of renal fibrosis. This study explores the pro-fibrotic response of tacrolimus exposure in relation to the differential capacity for tacrolimus metabolism in proximal tubule cells (PTCs) with a variable (pharmaco)genetic background. METHODS: PTCs were obtained from protocol allograft biopsies with different combinations of CYP3A5 and ABCB1 variants and were incubated with tacrolimus within the concentration range found in vivo. Gene and protein expression, CYP3A5 and P-glycoprotein function, and tacrolimus metabolites were measured in PTC. Connective tissue growth factor (CTGF) expression was assessed in protocol biopsies of kidney allograft recipients. RESULTS: PTCs produce CTGF in response to escalating tacrolimus exposure, which is approximately 2-fold higher in cells with the CYP3A5*1 and ABCB1 TT combination in vitro. Increasing tacrolimus exposure results in relative higher generation of the main tacrolimus metabolite {13-O-desmethyl tacrolimus [M1]} in cells with this same genetic background. Protocol biopsies show a larger increase in in vivo CTGF tissue expression over time in TT vs. CC/CT but was not affected by the CYP3A5 genotype. CONCLUSIONS: Tacrolimus exposure induces a pro-fibrotic response in a PTC model in function of the donor pharmacogenetic background associated with tacrolimus metabolism. This finding provides a mechanistic insight into the nephrotoxicity associated with tacrolimus treatment and offers opportunities for a tailored immunosuppressive treatment.
Assuntos
Nefropatias , Transplante de Rim , Humanos , Tacrolimo , Citocromo P-450 CYP3A/genética , Imunossupressores/farmacologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Genótipo , Polimorfismo de Nucleotídeo Único , Subfamília B de Transportador de Cassetes de Ligação de ATP/genéticaRESUMO
Hemolytic uremic syndrome can be initiated by Escherichia coli infections (Shiga-toxin-producing enterohemorrhagic Escherichia coli hemolytic uremic syndrome). When hemoglobin and heme released from ruptured erythrocytes interact with the kidney cells, this can result in platelet activation, vascular inflammation and occlusion, and kidney injury. Pirschel et al. now report that in the absence of protective mechanisms against free hemoglobin and heme, heme-induced kidney injury can be exacerbated. Therapeutic strategies should therefore also target heme-mediated deleterious effects in (severely ill) patients with Shiga-toxin-producing enterohemorrhagic Escherichia coli hemolytic uremic syndrome.
Assuntos
Infecções por Escherichia coli , Síndrome Hemolítico-Urêmica , Escherichia coli Shiga Toxigênica , Infecções por Escherichia coli/complicações , Infecções por Escherichia coli/tratamento farmacológico , Heme/uso terapêutico , Síndrome Hemolítico-Urêmica/terapia , Humanos , Rim , Toxina Shiga/uso terapêuticoRESUMO
Factor I (FI) is one of the main inhibitors of complement activity, and numerous rare coding variants have been reported in patients with age-related macular degeneration, atypical hemolytic uremic syndrome and C3 glomerulopathy. Since many of these variants are of unknown clinical significance, this study aimed to determine the effect of rare coding variants in the complement factor I (CFI) gene on FI expression. We measured FI levels in plasma samples of carriers of rare coding variants and in vitro in the supernatants of epithelial cells expressing recombinant FI. FI levels were measured in 177 plasma samples of 155 individuals, carrying 24 different rare coding variants in CFI. In carriers of the variants p.Gly119Arg, p.Leu131Arg, p.Gly188Ala and c.772G>A (r.685_773del), significantly reduced FI plasma levels were detected. Furthermore, recombinant FI expression levels were determined for 126 rare coding variants. Of these variants 68 (54%) resulted in significantly reduced FI expression in supernatant compared to wildtype (WT). The recombinant protein expression levels correlated significantly with the FI level in plasma of carriers of CFI variants. In this study, we performed the most comprehensive FI expression level analysis of rare coding variants in CFI to date. More than half of CFI variants lead to reduced FI expression, which might impair complement regulation in vivo. Our study will aid the interpretation of rare coding CFI variants identified in clinical practice, which is in particular important in light of patient inclusion in ongoing clinical trials for CFI gene supplementation in AMD.
Assuntos
Síndrome Hemolítico-Urêmica Atípica/genética , Fator I do Complemento/genética , Fibrinogênio/genética , Degeneração Macular/genética , Idoso , Idoso de 80 Anos ou mais , Alelos , Síndrome Hemolítico-Urêmica Atípica/sangue , Síndrome Hemolítico-Urêmica Atípica/patologia , Feminino , Regulação da Expressão Gênica/genética , Predisposição Genética para Doença , Genótipo , Heterozigoto , Humanos , Degeneração Macular/sangue , Degeneração Macular/patologia , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
BACKGROUND: Unilateral nephrectomy is a relatively common procedure in children which results in a solitary functioning kidney (SFK). Living with an SFK predisposes to kidney injury, but it remains unknown which children are most at risk. We aimed to investigate kidney injury rates in patients who underwent unilateral nephrectomy in childhood and to investigate differences among nephrectomies performed for a congenital anomaly, malignancy or other condition. METHODS: MEDLINE and EMBASE were searched for studies reporting kidney injury rates [i.e. proteinuria, hypertension and/or a decreased glomerular filtration rate (GFR)] of patients who underwent unilateral nephrectomy during childhood. Studies including five or more patients with at least 12 months of follow-up were eligible. Analyses were performed using random effects models and stratified by indication for nephrectomy. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines were used for reporting. RESULTS: Over 5000 unique articles were screened, of which 53 studies reporting on >4000 patients were included in the analyses. Proteinuria, hypertension and a decreased GFR were present in 15.3, 14.5 and 11.9% of patients, respectively. Heterogeneity among the studies was large in several subgroups, impairing quantitative meta-analyses. However, none of our analyses indicated differences in injury rates between a congenital anomaly or malignancy as an indication for nephrectomy. CONCLUSIONS: Unilateral nephrectomy during childhood results in signs of kidney injury in >10% of patients, with no clear difference between the indications for nephrectomy. Therefore, structured follow-up is necessary in all children who underwent nephrectomy, regardless of the indication.
Assuntos
Hipertensão , Nefrectomia , Humanos , Nefrectomia/efeitos adversos , Nefrectomia/métodos , Rim , Proteinúria/epidemiologia , Proteinúria/etiologia , Hipertensão/etiologiaRESUMO
The last remaining population of European sturgeon (Acipenser sturio) lives in the Gironde-Garonne-Dordogne (France) catchment (GGD). Captive young individuals are released into the GGD hydrosystem each year, as part of a restocking programme. This study aims to assess the health status of juveniles A. sturio to current conditions in the GGD hydrosystem, to evaluate their capacity to survive and grow in a moderately anthropized ecosystems. 3-month-old farmed sturgeons were exposed for one month in experimental conditions that mimic the environmental conditions in the Garonne and Dordogne rivers, followed by five months of depuration. After one month of exposure, fish exposed to Dordogne and Garonne waters bioaccumulated higher levels of metals and persistent organic pollutants, displayed a reduced hepato-somatic index, and had depleted levels of lipids and glycogen content in their liver, when compared with the Reference group. However, metabolic and swimming performance, as well as the costs of swimming were not impaired. After the 5 months depuration, a significant decrease of K was observed for all exposure conditions. HSI also decreased with time. The overall health status and adaptive capacity of juvenile A. sturio appeared to be maintained over the experimental 6 months' period. Juveniles of A. sturio seem to have the adaptive capacity to survive and grow in the GGD hydrosystem, after being released as part of a restocking programme.
Assuntos
Poluentes Orgânicos Persistentes , Rios , Animais , Ecossistema , Peixes , Humanos , Lactente , MetaisRESUMO
Hemolytic uremic syndrome (HUS) is characterized by a triad of symptoms consisting of hemolytic anemia, thrombocytopenia and acute renal failure. The most common form of HUS is caused by an infection with Shiga toxin (Stx) producing Escherichia coli bacteria (STEC-HUS), and the kidneys are the major organs affected. The development of HUS after an infection with Stx occurs most frequently in children under the age of 5 years. However, the cause for the higher incidence of STEC-HUS in children compared to adults is still not well understood. Human glomerular microvascular endothelial cells (HGMVECs) isolated and cultured from pediatric and adult kidney tissue were investigated with respect to Stx binding and different cellular responses. Shiga toxin-1 (Stx-1) inhibited protein synthesis in both pediatric and adult HGMVECs in a dose-dependent manner at basal conditions. The preincubation of pediatric and adult HGMVECs for 24 hrs with TNFα resulted in increased Stx binding to the cell surface and a 20-40% increase in protein synthesis inhibition in both age groups. A decreased proliferation of cells was found when a bromodeoxyuridine (BrdU) assay was performed. A trend towards a delay in endothelial wound closure was visible when pediatric and adult HGMVECs were incubated with Stx-1. Although minor differences between pediatric HGMVECs and adult HGMVECs were found in the assays applied in this study, no significant differences were observed. In conclusion, we have demonstrated that in vitro primary HGMVECs isolated from pediatric and adult kidneys do not significantly differ in their cell biological responses to Stx-1.
Assuntos
Células Endoteliais/metabolismo , Mesângio Glomerular/metabolismo , Microvasos/metabolismo , Toxina Shiga I/toxicidade , Adulto , Células Cultivadas , Pré-Escolar , Relação Dose-Resposta a Droga , Células Endoteliais/patologia , Feminino , Mesângio Glomerular/patologia , Humanos , Masculino , Microvasos/patologiaRESUMO
AIMS: To investigate the nature and extent of microbial contamination in five categories of used cosmetic products (lipstick, lip gloss, eyeliners, mascaras and beauty blenders) and highlight the potential risk posed to consumers in the UK. METHODS AND RESULTS: Used products were donated and microbial contents were determined by microbial culture and identification. About 79-90% of all used products were contaminated with bacteria, with bacterial loads ranging between 102 and 103 CFU per ml, beauty blenders contained an average load of >106 CFU per ml. Presence of Staphylococcus aureus, Escherichia coli and Citrobacter freundii was detected. Enterobacteriaceae and fungi were detected in all product types, and were prevalent in beauty blenders (26·58 and 56·96% respectively). Ninety-three per cent of beauty blenders had not been cleaned and 64% had been dropped on the floor and continued to be used. CONCLUSIONS: Significant levels of microbial contamination occur during use of cosmetic products and presence of pathogenic organisms pose a potential risk to health. SIGNIFICANCE AND IMPACT OF THE STUDY: The nature and high level of contamination in used cosmetic products indicate that greater user awareness and education are required. Manufacturers should ensure that product expiry dates are prominently displayed and consumers can identify the symbols used on product packaging.
Assuntos
Bactérias/isolamento & purificação , Cosméticos/análise , Fungos/isolamento & purificação , Bactérias/classificação , Bactérias/genética , Contagem de Colônia Microbiana , Qualidade de Produtos para o Consumidor , Fungos/classificação , Fungos/genética , HumanosRESUMO
Although mitochondrial disorders are clinically heterogeneous, they frequently involve the central nervous system and are among the most common neurogenetic disorders. Identifying the causal genes has benefited enormously from advances in high-throughput sequencing technologies; however, once the defect is known, researchers face the challenge of deciphering the underlying disease mechanism. Here we characterize large biallelic deletions in the region encoding the ATAD3C, ATAD3B and ATAD3A genes. Although high homology complicates genomic analysis of the ATAD3 defects, they can be identified by targeted analysis of standard single nucleotide polymorphism array and whole exome sequencing data. We report deletions that generate chimeric ATAD3B/ATAD3A fusion genes in individuals from four unrelated families with fatal congenital pontocerebellar hypoplasia, whereas a case with genomic rearrangements affecting the ATAD3C/ATAD3B genes on one allele and ATAD3B/ATAD3A genes on the other displays later-onset encephalopathy with cerebellar atrophy, ataxia and dystonia. Fibroblasts from affected individuals display mitochondrial DNA abnormalities, associated with multiple indicators of altered cholesterol metabolism. Moreover, drug-induced perturbations of cholesterol homeostasis cause mitochondrial DNA disorganization in control cells, while mitochondrial DNA aggregation in the genetic cholesterol trafficking disorder Niemann-Pick type C disease further corroborates the interdependence of mitochondrial DNA organization and cholesterol. These data demonstrate the integration of mitochondria in cellular cholesterol homeostasis, in which ATAD3 plays a critical role. The dual problem of perturbed cholesterol metabolism and mitochondrial dysfunction could be widespread in neurological and neurodegenerative diseases.
Assuntos
Adenosina Trifosfatases/genética , Cerebelo/anormalidades , DNA Mitocondrial/genética , Proteínas de Membrana/genética , Doenças Mitocondriais/genética , Proteínas Mitocondriais/genética , Malformações do Sistema Nervoso/genética , ATPases Associadas a Diversas Atividades Celulares , Adulto , Cerebelo/diagnóstico por imagem , Cerebelo/fisiopatologia , Consanguinidade , Deficiências do Desenvolvimento/diagnóstico por imagem , Deficiências do Desenvolvimento/genética , Deficiências do Desenvolvimento/fisiopatologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Doenças Mitocondriais/diagnóstico por imagem , Doenças Mitocondriais/fisiopatologia , Malformações do Sistema Nervoso/diagnóstico por imagem , Malformações do Sistema Nervoso/fisiopatologiaRESUMO
Ecosystem fragmentation is a serious threat to biodiversity and one of the main challenges in ecosystem restoration. River continuity restoration (RCR) has often targeted diadromous fishes, a group of species supporting strong cultural and economic values and especially sensitive to river fragmentation. Yet it has frequently produced mixed results and diadromous fishes remain at very low levels of abundance. Against this background, this paper presents the main challenges for defining, evaluating and achieving effective RCR. We first identify challenges specific to disciplines. In ecology, there is a need to develop quantitative and mechanistic models to support decision making, accounting for both direct and indirect impacts of river obstacles and working at the river catchment scale. In a context of dwindling abundances and reduced market value, cultural services provided by diadromous fishes are becoming increasingly prominent. Methods for carrying out economic quantification of non-market values of diadromous fishes become ever more urgent. Given current challenges for rivers to meet all needs sustainably, conflicts arise over the legitimate use of water resources for human purposes. Concepts and methods from political science and geography are needed to develop understandings on how the political work of public authorities and stakeholders can influence the legitimacy of restoration projects. Finally, the most exciting challenge is to combine disciplinary outcomes to achieve a multidisciplinary approach to RCR. Accordingly, the co-construction of intermediary objects and diagrams of flows of knowledge among disciplines can be first steps towards new frameworks supporting restoration design and planning.
Assuntos
Conservação dos Recursos Naturais/métodos , Ecossistema , Peixes , Rios , Animais , Biodiversidade , Ecologia , Geografia , Humanos , Movimentos da ÁguaRESUMO
Atypical hemolytic uremic syndrome (aHUS) is a disorder characterized by thrombocytopenia and microangiopathic hemolytic anemia due to endothelial injury. aHUS is felt to be caused by defective complement regulation due to underlying genetic mutations in complement regulators or activators, most often of the alternative pathway. Mutations causing aHUS can be subdivided into two groups, loss of function mutations (affecting factor H, factor H-related proteins, membrane co-factor protein, and factor I), and gain of function mutations (affecting factor B and C3). As more information becomes available on the relationship between specific mutations and clinical outcome, complete genetic workup of aHUS patients becomes more and more important. In this review, we will discuss the genetic background of aHUS, the role of complement for aHUS pathogenesis, and the different groups of specific mutations known to be involved in the pathogenesis of aHUS.
RESUMO
BACKGROUND: The role of complement in the atypical form of hemolytic uremic syndrome (aHUS) has been investigated extensively in recent years. As the HUS-associated bacteria Shiga-toxin-producing Escherichia coli (STEC) can evade the complement system, we hypothesized that complement dysregulation is also important in infection-induced HUS. METHODS: Serological profiles (C3, FH, FI, AP activity, C3d, C3bBbP, C3b/c, TCC, αFH) and genetic profiles (CFH, CFI, CD46, CFB, C3) of the alternative complement pathway were prospectively determined in the acute and convalescent phase of disease in children newly diagnosed with STEC-HUS or aHUS. Serological profiles were compared with those of 90 age-matched controls. RESULTS: Thirty-seven patients were studied (26 STEC-HUS, 11 aHUS). In 39 % of them, including 28 % of STEC-HUS patients, we identified a genetic and/or acquired complement abnormality. In all patient groups, the levels of investigated alternative pathway (AP) activation markers were elevated in the acute phase and normalized in remission. The levels were significantly higher in aHUS than in STEC-HUS patients. CONCLUSIONS: In both infection-induced HUS and aHUS patients, complement is activated in the acute phase of the disease but not during remission. The C3d/C3 ratio displayed the best discrepancy between acute and convalescent phase and between STEC-HUS and aHUS and might therefore be used as a biomarker in disease diagnosis and monitoring. The presence of aberrations in the alternative complement pathway in STEC-HUS patients was remarkable, as well.
Assuntos
Síndrome Hemolítico-Urêmica Atípica/genética , Via Alternativa do Complemento/genética , Adolescente , Síndrome Hemolítico-Urêmica Atípica/sangue , Síndrome Hemolítico-Urêmica Atípica/imunologia , Biomarcadores/sangue , Estudos de Casos e Controles , Criança , Pré-Escolar , Fator H do Complemento/genética , Fator H do Complemento/imunologia , Via Alternativa do Complemento/imunologia , Feminino , Humanos , Lactente , Masculino , Mutação , Estudos Prospectivos , Recidiva , Escherichia coli Shiga ToxigênicaRESUMO
Extremophilic organisms require specialized enzymes for their exotic metabolisms. Acid-loving thermophilic Archaea that live in the mudpots of volcanic solfataras obtain their energy from reduced sulphur compounds such as hydrogen sulphide (H(2)S) and carbon disulphide (CS(2)). The oxidation of these compounds into sulphuric acid creates the extremely acidic environment that characterizes solfataras. The hyperthermophilic Acidianus strain A1-3, which was isolated from the fumarolic, ancient sauna building at the Solfatara volcano (Naples, Italy), was shown to rapidly convert CS(2) into H(2)S and carbon dioxide (CO(2)), but nothing has been known about the modes of action and the evolution of the enzyme(s) involved. Here we describe the structure, the proposed mechanism and evolution of a CS(2) hydrolase from Acidianus A1-3. The enzyme monomer displays a typical ß-carbonic anhydrase fold and active site, yet CO(2) is not one of its substrates. Owing to large carboxy- and amino-terminal arms, an unusual hexadecameric catenane oligomer has evolved. This structure results in the blocking of the entrance to the active site that is found in canonical ß-carbonic anhydrases and the formation of a single 15-Å-long, highly hydrophobic tunnel that functions as a specificity filter. The tunnel determines the enzyme's substrate specificity for CS(2), which is hydrophobic. The transposon sequences that surround the gene encoding this CS(2) hydrolase point to horizontal gene transfer as a mechanism for its acquisition during evolution. Our results show how the ancient ß-carbonic anhydrase, which is central to global carbon metabolism, was transformed by divergent evolution into a crucial enzyme in CS(2) metabolism.
Assuntos
Acidianus/enzimologia , Dissulfeto de Carbono/metabolismo , Evolução Molecular , Hidrolases/genética , Acidianus/classificação , Acidianus/genética , Domínio Catalítico , Cristalografia por Raios X , Hidrolases/química , Modelos Moleculares , Dados de Sequência Molecular , Mutação , Filogenia , Estrutura Terciária de ProteínaRESUMO
We aimed to measure gastric antral cross-sectional area with ultrasound and estimate the gastric volume of 300 patients before unplanned surgery, fasted for at least six hours. Measurements were successfully recorded in 263 semi-recumbent patients. The median (IQR [range]) area was 333 (241-472 [28-1803]) mm2 and the mean (SD) estimated volume was 45.8 (34.0) ml. The area exceeded 410 mm2 in 92/263 (35%) measurements. Body mass index and morphine administration were associated with larger gastric areas on multivariable linear regression analysis, with beta coefficient (95%CI) 0.02 (0.01-0.04), p = 0.01, 0.23 (0.01-0.46), p = 0.04, respectively. Fasting time was not associated with gastric area and therefore could not substitute for ultrasound measurements in this cohort.
Assuntos
Aspiração Respiratória de Conteúdos Gástricos/diagnóstico por imagem , Aspiração Respiratória de Conteúdos Gástricos/prevenção & controle , Estômago/diagnóstico por imagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anatomia Transversal , Índice de Massa Corporal , Estudos de Coortes , Estudos Transversais , Serviços Médicos de Emergência , Jejum , Feminino , Esvaziamento Gástrico , Humanos , Masculino , Pessoa de Meia-Idade , Morfina/farmacologia , Antro Pilórico/diagnóstico por imagem , Reprodutibilidade dos Testes , Ultrassonografia , Adulto JovemRESUMO
BACKGROUND: Because the International Cancer Benchmarking Partnership, in a study of diagnosis years between 1995 and 2007, showed lower-than-expected survival for Manitoba's ovarian cancer patients, we undertook an analysis to describe the features of ovarian cancer diagnosed in Manitoba during a 20-year period. We also determined the most recent trends in survival to see if the previous results were sustained. METHODS: In this retrospective cohort study, ovarian cancer cases diagnosed during 1992-2011 were extracted from the Manitoba Cancer Registry. The incidence of ovarian cancer was calculated for the overall group and for age, morphology, residence, treatment, and stage. Trends over time, with a particular focus on changes that might correlate with poor survival, were analyzed. The 1- and 3-year relative survival rates were also calculated. RESULTS: The incidence of ovarian cancer did not vary over time (p = 0.640), even when stratified by age or morphology groups. Use of adjuvant chemotherapy decreased (p = 0.005) and use of neoadjuvant chemotherapy increased over time (p = 0.002). Diagnoses of stage iv cancers declined over time (p < 0.020). Trends in incidence did not coincide with previously observed decreases in relative survival. CONCLUSIONS: A decline in diagnoses of stage iv ovarian cancer could be responsible for a recent increase in relative survival. However, sample size might have limited power in some analyses, and the previously reported decrease in relative survival might have been due to a random fluctuation in the data. Future efforts will focus on continued monitoring of the patterns of ovarian cancer presentation and outcomes in Manitoba.
RESUMO
Streptococcus pneumoniae is a major cause of life-threatening infections. Complement activation plays a vital role in opsonophagocytic killing of pneumococci in blood. Initial complement activation via the classical and lectin pathways is amplified through the alternative pathway amplification loop. Alternative pathway activity is inhibited by complement factor H (FH). Our study demonstrates the functional consequences of the variability in human serum FH levels on host defense. Using an in vivo mouse model combined with human in vitro assays, we show that the level of serum FH correlates with the efficacy of opsonophagocytic killing of pneumococci. In summary, we found that FH levels determine a delicate balance of alternative pathway activity, thus affecting the resistance to invasive pneumococcal disease. Our results suggest that variation in FH expression levels, naturally occurring in the human population, plays a thus far unrecognized role in the resistance to invasive pneumococcal disease.
Assuntos
Infecções Pneumocócicas/imunologia , Animais , Complemento C3/imunologia , Fator H do Complemento/imunologia , Resistência à Doença/imunologia , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Infecções Pneumocócicas/prevenção & controleRESUMO
BACKGROUND: Older women with breast cancer have poorer relative survival outcomes, but whether achieving earlier stage at diagnosis would translate to substantial reductions in mortality is uncertain. METHODS: We analysed data on East of England women with breast cancer (2006-2010) aged 70+ years. We estimated survival for different stage-deprivation-age group strata using both the observed and a hypothetical stage distribution (assuming that all women aged 75+ years acquired the stage distribution of those aged 70-74 years). We subsequently estimated deaths that could be postponed beyond 5 years from diagnosis if women aged 75+ years had the hypothetical stage distribution. We projected findings to the English population using appropriate age and socioeconomic group weights. RESULTS: For a typically sized annual cohort in the East of England, 27 deaths in women with breast cancer aged 75+ years can be postponed within 5 years from diagnosis if their stage distribution matched that of the women aged 70-74 years (4.8% of all 566 deaths within 5 years post diagnosis in this population). Under assumptions, we estimate that the respective number for England would be 280 deaths (5.0% of all deaths within 5 years post diagnosis in this population). CONCLUSIONS: The findings support ongoing development of targeted campaigns aimed at encouraging prompt presentation in older women.
Assuntos
Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/patologia , Carcinoma Lobular/patologia , Disparidades nos Níveis de Saúde , Disparidades em Assistência à Saúde , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/mortalidade , Carcinoma Ductal de Mama/diagnóstico , Carcinoma Ductal de Mama/mortalidade , Carcinoma Lobular/diagnóstico , Carcinoma Lobular/mortalidade , Estudos de Coortes , Inglaterra , Feminino , Humanos , Fatores Socioeconômicos , Taxa de SobrevidaRESUMO
BACKGROUND: Although inequalities in cancer survival are thought to reflect inequalities in stage at diagnosis, little evidence exists about the size of potential survival gains from eliminating inequalities in stage at diagnosis. METHODS: We used data on patients diagnosed with malignant melanoma in the East of England (2006-2010) to estimate the number of deaths that could be postponed by completely eliminating socioeconomic and sex differences in stage at diagnosis after fitting a flexible parametric excess mortality model. RESULTS: Stage was a strong predictor of survival. There were pronounced socioeconomic and sex inequalities in the proportion of patients diagnosed at stages III-IV (12 and 8% for least deprived men and women and 25 and 18% for most deprived men and women, respectively). For an annual cohort of 1025 incident cases in the East of England, eliminating sex and deprivation differences in stage at diagnosis would postpone approximately 24 deaths to beyond 5 years from diagnosis. Using appropriate weighting, the equivalent estimate for England would be around 215 deaths, representing 11% of all deaths observed within 5 years from diagnosis in this population. CONCLUSIONS: Reducing socioeconomic and sex inequalities in stage at diagnosis would result in substantial reductions in deaths within 5 years of a melanoma diagnosis.
Assuntos
Disparidades nos Níveis de Saúde , Disparidades em Assistência à Saúde , Melanoma/mortalidade , Modelos Estatísticos , Neoplasias Cutâneas/mortalidade , Classe Social , Adulto , Idoso , Idoso de 80 Anos ou mais , Inglaterra , Feminino , Humanos , Masculino , Melanoma/diagnóstico , Melanoma/patologia , Pessoa de Meia-Idade , Mortalidade , Estadiamento de Neoplasias , Fatores Sexuais , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/patologia , Fatores Socioeconômicos , Taxa de SobrevidaRESUMO
The application of multiple imputation (MI) techniques as a preliminary step to handle missing values in data analysis is well established. The MI method can be classified into two broad classes, the joint modeling and the fully conditional specification approaches. Their relative performance for the longitudinal ordinal data setting under the missing at random (MAR) assumption is not well documented. This article intends to fill this gap by conducting a large simulation study on the estimation of the parameters of a longitudinal proportional odds model. The two MI methods are also illustrated in quality of life data from a cancer clinical trial.
Assuntos
Estudos Longitudinais , Modelos Estatísticos , Pacientes Desistentes do Tratamento , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Neoplasias do Sistema Nervoso Central/tratamento farmacológico , Neoplasias do Sistema Nervoso Central/radioterapia , Simulação por Computador , Glioblastoma/tratamento farmacológico , Glioblastoma/radioterapia , Humanos , Modelos Logísticos , Análise Multivariada , Pacientes Desistentes do Tratamento/estatística & dados numéricos , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Distribuições Estatísticas , Inquéritos e QuestionáriosRESUMO
AIMS: The relation between selenium status and risk of Type 2 diabetes is controversial. We aimed to evaluate associations of serum selenium, a marker of dietary selenium, with measures of glucose metabolism and risk of diabetes. METHODS: We used data from a population-based, longitudinal cohort of 1925 Swedish men who were 50 years old and did not have diabetes at baseline in the 1970s. At baseline, an intravenous glucose tolerance test was performed and, at a follow-up examination after 20 years, an oral glucose tolerance test and a hyperinsulinaemic euglycaemic clamp for the assessment of insulin sensitivity were conducted. RESULTS: At baseline, the mean (standard deviation) selenium concentration was 75.6 (14.3) µg/l. During 20 years of follow-up, 88 incident cases of diabetes occurred in 1024 participants with follow-up data. Baseline serum selenium levels were not associated with risk of diabetes (odds ratio 1.06; 95% CI 0.83-1.38). Higher selenium levels were associated with lower early insulin response (standardized ß -0.08; 95% CI -0.14 to -0.03) at baseline after adjusting for potential confounders, but not with any other measures of ß-cell function or insulin sensitivity at baseline or follow-up. The association with early insulin response was non-significant after taking multiple testing into account. CONCLUSIONS: Our results do not support a role of dietary selenium in the development of disturbances in glucose metabolism or diabetes in older individuals.