RESUMO
Myocardial fibrosis confers an almost threefold mortality risk in heart disease. There are no prognostic therapies and novel therapeutic targets are needed. Many thousands of unannotated small open reading frames (smORFs) have been identified across the genome with potential to produce micropeptides (< 100 amino acids). We sought to investigate the role of smORFs in myocardial fibroblast activation.Analysis of human cardiac atrial fibroblasts (HCFs) stimulated with profibrotic TGFß1 using RNA sequencing (RNA-Seq) and ribosome profiling (Ribo-Seq) identified long intergenic non-coding RNA LINC01013 as TGFß1 responsive and containing an actively translated smORF. Knockdown of LINC01013 using siRNA reduced expression of profibrotic markers at baseline and blunted their response to TGFß1. In contrast, overexpression of a codon-optimised smORF invoked a profibrotic response comparable to that seen with TGFß1 treatment, whilst FLAG-tagged peptide associated with the mitochondria.Together, these data support a novel LINC01013 smORF micropeptide-mediated mechanism of fibroblast activation. TGFß1 stimulation of atrial fibroblasts induces expression of LINC01013, whose knockdown reduces fibroblast activation. Overexpression of a smORF contained within LINC01013 localises to mitochondria and activates fibroblasts.
Assuntos
Fibrilação Atrial , RNA Longo não Codificante , Humanos , Proteômica , RNA Longo não Codificante/genética , Fibroblastos , MicropeptídeosRESUMO
BACKGROUND: Sinonasal complaints contribute to low adherence to continuous positive airway pressure (CPAP) treatment. We aimed to investigate sinonasal health in obstructive sleep apnoea (OSA) patients, using the sinonasal outcome test-22 (SNOT-22), and to analyse whether SNOT-22 is affected by CPAP adherence. We also aimed to investigate whether peak nasal inspiratory flow (PNIF) was able to predict adherence to CPAP. METHODS: The study population comprised 197 OSA patients (60 females) initiating CPAP treatment. The SNOT-22, PNIF and the Epworth Sleepiness Scale were assessed at baseline and follow-up. One-night polygraphy, the Hospital Anxiety and Depression Scale, peak expiratory flow and health-related issues were assessed at baseline. At follow-up, the patients were categorised into adherent (more than 4 hours/night) and non-adherent (less than 4 hours/night) to CPAP treatment. RESULTS: The average time for following up CPAP treatment was (mean plus or minus SD) 24.0 plus or minus 23.9 days and it did not differ significantly between the groups. The SNOT-22 score was elevated among all OSA patients, 36.1 plus or minus 19.4. There was a larger improvement in the SNOT-22 score at follow-up among adherent CPAP users compared with non-adherent users (-10.4 plus or minus 13.9 vs. -3.2 plus or minus 15.4). A PNIF value of less than 100 litres/min increased the risk of non-adherence to CPAP with an adjusted odds ratio (OR) of 2.40 ((95% CI 1.16-5.00)). CONCLUSIONS: The SNOT-22 was elevated in patients with OSA, indicating a considerable sinonasal disease burden. The SNOT-22 improved with good CPAP adherence. A low PNIF value was able to predict poor CPAP adherence. Both the SNOT-22 and PNIF can be valuable tools in the evaluation of OSA patients and in the management of CPAP treatment.
Assuntos
Teste de Desfecho Sinonasal , Apneia Obstrutiva do Sono , Pressão Positiva Contínua nas Vias Aéreas , Feminino , Humanos , Apneia Obstrutiva do Sono/terapiaRESUMO
The heterogeneity of myelodysplastic syndromes (MDSs) has made evaluating patient response to treatment challenging. In 2006, the International Working Group (IWG) proposed a revision to previously published standardized response criteria (IWG 2000) for uniformly evaluating clinical responses in MDSs. These IWG 2006 criteria have been used prospectively in many clinical trials in MDSs, but proved challenging in several of them, especially for the evaluation of erythroid response. In this report, we provide rationale for modifications (IWG 2018) of these recommendations, mainly for "hematological improvement" criteria used for lower-risk MDSs, based on recent practical and reported experience in clinical trials. Most suggestions relate to erythroid response assessment, which are refined in an overall more stringent manner. Two major proposed changes are the differentiation between "procedures" and "criteria" for hematologic improvement-erythroid assessment and a new categorization of transfusion-burden subgroups.
Assuntos
Ensaios Clínicos como Assunto/normas , Hematologia/métodos , Hematologia/normas , Síndromes Mielodisplásicas/terapia , Transfusão de Sangue , Linhagem da Célula , Progressão da Doença , Transfusão de Eritrócitos , Eritrócitos/citologia , Humanos , Cooperação Internacional , Contagem de Leucócitos , Neutrófilos , Contagem de Plaquetas , Guias de Prática Clínica como Assunto , Qualidade de Vida , Recidiva , Comportamento de Redução do Risco , Sociedades Médicas , Resultado do TratamentoRESUMO
Protein kinases are quintessential regulators of cellular function. Numerous pathologies are intimately linked to the dysregulated activity of a particular protein kinase. Herein we report a technology based on a proximity-induced chemical transformation that enables the detection and imaging of specific kinases. Using two probes that target the nucleotide-binding site and substrate binding site of a target kinase respectively, the reagents appended on the probes are brought within reactive distance thereby enabling the chemical transformation. The reaction used for sensing is a ruthenium-photocatalyzed reduction of a pyridinium immolative linker, which uncages a fluorophore (rhodamine). We demonstrate that this technology can be used to discriminate between closely related kinases with a high signal to noise ratio. We further demonstrate that the technology operates within the complexity of a cellular context with a good correlation between the level of kinase activity and fluorescence output.
RESUMO
BACKGROUND: We evaluated the impact of different case definition algorithms on the prevalence of paediatric inflammatory bowel disease (IBD), Crohn's disease (CD) and ulcerative colitis (UC) and to compare the occurrence of certain diseases compared to matched controls. METHODS: Paediatric patients (<18 years) were identified via ICD codes for UC and CD in Swedish registers between 1993 and 2010 (n = 1432). Prevalence was defined as ≥2 IBD-related visits. Prevalence of treated children in 2010 was defined as ≥2 IBD-related visits with one visit and ≥1 dispensed IBD-related drug prescription in 2010. To test the robustness of the estimates, prevalence was also calculated according to alternative case definitions. The presence of rheumatic, hepatobiliary, pancreatic, and dermatologic diseases were compared with age-/sex-/county-of-residence-matched general population controls. RESULTS: The IBD prevalence was 75/100,000 (CD: 29/100,000; UC: 30/100,000; patients with IBD-U: 16/100,000). Prevalence of treated disease in 2010 was 62/100,000 (CD: 23/100,000; UC: 25/100,000; patients with IBD-U: 13/100,000). When age restrictions were employed, the prevalence estimate decreased (<17y: 61/100,000, <16y: 49/100,000 and <15y: 38/100,000). Compared to general population controls (n = 8583), children with IBD had a higher prevalence of dermatologic (4.7% vs. 0.6%), hepatobiliary (including primary sclerosing cholangitis) (5.5% vs. 0.1%), pancreatic (1.7% vs. 0%) and rheumatic diseases (7.2% vs. 1.2%; all P < 0.01). CONCLUSIONS: The overall prevalence of paediatric IBD in Sweden was similar to that in earlier regional cohorts. IBD patients had a higher prevalence of comorbid conditions than matched general population controls.
Assuntos
Doenças Inflamatórias Intestinais/epidemiologia , Adolescente , Criança , Pré-Escolar , Colite Ulcerativa/epidemiologia , Colite Ulcerativa/terapia , Comorbidade , Doença de Crohn/epidemiologia , Doença de Crohn/terapia , Feminino , Serviços de Saúde/estatística & dados numéricos , Humanos , Lactente , Recém-Nascido , Doenças Inflamatórias Intestinais/terapia , Masculino , Prevalência , Sistema de Registros , Suécia/epidemiologiaRESUMO
BACKGROUND: The EUMDS registry is an unique prospective, longitudinal observational registry enrolling newly diagnosed patients with lower-risk myelodysplastic syndrome (MDS) from 17 European countries from both university hospitals and smaller regional hospitals. OBJECTIVE: The aim of this study was to describe the usage and clinical impact of erythropoiesis-stimulating agents (ESAs) in 1696 patients enrolled between 2008 and 2014. METHODS: The effects of ESAs on outcomes were assessed using proportional hazards models weighting observations by propensity to receive ESA treatment within a subset of anaemic patients with or without a regular transfusion need. RESULTS: ESA treatment (median duration of 27.5 months, range 0-77 months) was administered to 773 patients (45.6%). Outcomes were assessed in 897 patients (484 ESA treated and 413 untreated). ESA treatment was associated with a nonsignificant survival benefit (HR 0.82, 95% CI: 0.65-1.04, P = 0.09); this benefit was larger amongst patients without prior transfusions (P = 0.07). Amongst 539 patients for whom response to ESA treatment could be defined, median time to first post-ESA treatment transfusion was 6.1 months (IQR: 4.3-15.9 months) in those transfused before ESA treatment compared to 23.3 months (IQR: 7.0-47.8 months) in patients without prior transfusions (HR 2.4, 95% CI: 1.7-3.3, P < 0.0001). Responding patients had a better prognosis in terms of a lower risk of death (HR 0.65, 95% CI: 0.45-0.893, P = 0.018), whereas there was no significant effect on the risk of progression to acute myeloid leukaemia (HR 0.71, 95% CI: 0.39-1.29, P = 0.27). CONCLUSION: Appropriate use of ESAs can significantly delay the onset of a regular transfusion need in patients with lower-risk MDS.
Assuntos
Transfusão de Sangue , Hematínicos/uso terapêutico , Síndromes Mielodisplásicas/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/mortalidade , Estudos Prospectivos , Fatores de Risco , Taxa de Sobrevida , Fatores de Tempo , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: According to the hygiene hypothesis, insufficient immune activation by microbes increases the risk of allergy development. Staphylococcus aureus, which is part of the skin and gut microbiota of infants in Western countries, produces a variety of T-cell-activating enterotoxins, called superantigens. OBJECTIVES: To investigate whether early (0-2 months of age) gut colonization by S. aureus strains that carry specific superantigens and adhesins was related to subsequent development of atopic eczema in a Swedish birth cohort. METHODS: Staphylococcus aureus was isolated from rectal swabs and cultured quantitatively from faecal samples, with individual strains being tested for carriage of genes for superantigens and adhesins. Atopic eczema was diagnosed at onset of symptoms and at 18 months of age. RESULTS: Although the frequency of early gut colonization by S. aureus was not related to subsequent eczema development, the S. aureus strains that were found to colonize those infants who developed atopic eczema were less likely to carry the gene encoding the superantigen SElM (P = 0·008) and the gene for elastin-binding protein (P = 0·03), compared with strains that were isolated from infants who had not developed atopic eczema by 18 months of age. CONCLUSIONS: Gut colonization by S. aureus strains carrying a certain combination of superantigen and adhesin genes was negatively associated with subsequent development of atopic eczema. Such strains may provide stimulation and promote maturation of the infant immune system.
Assuntos
Adesinas Bacterianas/imunologia , Dermatite Atópica/etiologia , Microbioma Gastrointestinal/imunologia , Staphylococcus aureus/imunologia , Superantígenos/metabolismo , Adesinas Bacterianas/genética , Pré-Escolar , Colo/microbiologia , Dermatite Atópica/imunologia , Enterotoxinas/genética , Fezes/microbiologia , Humanos , Lactente , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificaçãoRESUMO
Labelling of proteins with a luminescent ruthenium complex enables the direct visualization and photocatalytic reduction of aryl azide in live cells. The confinement of catalysis to the labeled proteins was visualized using an azide-based immolative linker releasing a precipitating dye.
Assuntos
Azidas/química , Receptores ErbB/química , Corantes Fluorescentes/química , Compostos Organometálicos/química , Processos Fotoquímicos , Receptores de Estrogênio/química , Rutênio/química , Catálise , Linhagem Celular Tumoral , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , Células HEK293 , Humanos , Luminescência , Células MCF-7 , Estrutura Molecular , Oxirredução , Receptores de Estrogênio/metabolismoRESUMO
This prospective phase II study evaluated the efficacy of azacitidine (Aza)+erythropoietin (Epo) in transfusion-dependent patients with lower-risk myelodysplastic syndrome (MDS). Patients ineligible for or refractory to full-dose Epo+granulocyte colony stimulation factors for >8 weeks and a transfusion need of î¶4 units over 8 weeks were included. Aza 75 mg m(-2) d(-1), 5/28 days, was given for six cycles; non-responding patients received another three cycles combined with Epo 60 000 units per week. Primary end point was transfusion independence (TI). All patients underwent targeted mutational screen for 42 candidate genes. Thirty enrolled patients received î¶one cycle of Aza. Ten patients discontinued the study early, 7 due to adverse events including 2 deaths. Thirty-eight serious adverse events were reported, the most common being infection. Five patients achieved TI after six cycles and one after Aza+Epo, giving a total response rate of 20%. Mutational screening revealed a high frequency of recurrent mutations. Although no single mutation predicted for response, SF3A1 (n=3) and DNMT3A (n=4) were only observed in non-responders. We conclude that Aza can induce TI in severely anemic MDS patients, but efficacy is limited, toxicity substantial and most responses of short duration. This treatment cannot be generally recommended in lower-risk MDS. Mutational screening revealed a high frequency of mutations.
Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Azacitidina/farmacologia , Metilação de DNA/efeitos dos fármacos , Histonas/metabolismo , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/metabolismo , Acetilação/efeitos dos fármacos , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Células Cultivadas , Epigênese Genética/efeitos dos fármacos , Epigenômica , HumanosRESUMO
BACKGROUND: Asthma and rhinitis have been related to insomnia. The aim of this study was to further analyse the association between asthma, nasal symptoms and insomnia and to identify risk factors for sleep disturbance among patients with asthma, in a large population-based set of material. METHOD: In 2008, a postal questionnaire was sent to a random sample of 45 000 adults in four Swedish cities. The questionnaire included questions on insomnia, asthma, rhinitis, weight, height, tobacco use and physical activity. RESULTS: Twenty-five thousand six hundred and ten subjects participated. Asthma was defined as either current medication for asthma or at least one attack of asthma during the last 12 months, and 1830 subjects (7.15%) were defined as asthmatics. The prevalence of insomnia symptoms was significantly higher among asthmatics than non-asthmatics (47.3% vs 37.2%, <0.0001). In the subgroup reporting both asthma and nasal congestion, 55.8% had insomnia symptoms compared with 35.3% in subjects without both asthma and nasal congestion. The risk of insomnia increased with the severity of asthma, and the adjusted OR for insomnia was 2.65 in asthmatics with three symptoms compared with asthmatics without symptoms. Nasal congestion (OR 1.50), obesity (OR 1.54) and smoking (OR 1.71) also increased the risk of insomnia. CONCLUSION: Insomnia remains a common problem among asthmatics. Uncontrolled asthma and nasal congestion are important, treatable risk factors for insomnia. Lifestyle factors, such as smoking and obesity, are also risk factors for insomnia among asthmatics.
Assuntos
Asma/epidemiologia , Obstrução Nasal/epidemiologia , Distúrbios do Início e da Manutenção do Sono/epidemiologia , Adulto , Distribuição por Idade , Idoso , Asma/diagnóstico , Comorbidade , Intervalos de Confiança , Estudos Transversais , Feminino , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Obstrução Nasal/diagnóstico , Obesidade/epidemiologia , Razão de Chances , Prevalência , Medição de Risco , Distribuição por Sexo , Distúrbios do Início e da Manutenção do Sono/diagnóstico , Fumar/epidemiologia , Inquéritos e Questionários , Suécia/epidemiologiaAssuntos
Antineoplásicos/uso terapêutico , Deleção Cromossômica , Cromossomos Humanos Par 5 , Síndromes Mielodisplásicas/genética , Telômero , Talidomida/análogos & derivados , Progressão da Doença , Humanos , Lenalidomida , Síndromes Mielodisplásicas/tratamento farmacológico , Talidomida/uso terapêuticoRESUMO
BACKGROUND: Myelodysplastic syndromes are a diverse and common group of chronic hematologic cancers. The identification of new genetic lesions could facilitate new diagnostic and therapeutic strategies. METHODS: We used massively parallel sequencing technology to identify somatically acquired point mutations across all protein-coding exons in the genome in 9 patients with low-grade myelodysplasia. Targeted resequencing of the gene encoding RNA splicing factor 3B, subunit 1 (SF3B1), was also performed in a cohort of 2087 patients with myeloid or other cancers. RESULTS: We identified 64 point mutations in the 9 patients. Recurrent somatically acquired mutations were identified in SF3B1. Follow-up revealed SF3B1 mutations in 72 of 354 patients (20%) with myelodysplastic syndromes, with particularly high frequency among patients whose disease was characterized by ring sideroblasts (53 of 82 [65%]). The gene was also mutated in 1 to 5% of patients with a variety of other tumor types. The observed mutations were less deleterious than was expected on the basis of chance, suggesting that the mutated protein retains structural integrity with altered function. SF3B1 mutations were associated with down-regulation of key gene networks, including core mitochondrial pathways. Clinically, patients with SF3B1 mutations had fewer cytopenias and longer event-free survival than patients without SF3B1 mutations. CONCLUSIONS: Mutations in SF3B1 implicate abnormalities of messenger RNA splicing in the pathogenesis of myelodysplastic syndromes. (Funded by the Wellcome Trust and others.).
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Síndromes Mielodisplásicas/genética , Fosfoproteínas/genética , Mutação Puntual , Ribonucleoproteína Nuclear Pequena U2/genética , Eritrócitos/patologia , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Fenótipo , Fatores de Processamento de RNARESUMO
OBJECTIVE: Neuronal loss in the locus coeruleus (LC) is common in Alzheimer's disease (AD), dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD). The aims of the present study were to investigate LC degeneration in different dementia disorders including vascular dementia (VaD) and frontotemporal lobar degeneration (FTLD), to compare LC degeneration with severity of pathology in AD and DLB/PDD, to further evaluate the usefulness of a previously presented scoring system and to examine the predictive value of macroscopic assessment of the LC. METHODS: A horizontal mid-level section of the pons was examined in 200 neuropathologically examined cases with clinical dementia. A previous macroscopic assessment of the LC was performed in 149 of the cases. RESULTS: Cases with DLB/ PDD and AD presented with the highest microscopic LC degeneration scores, with significant differences compared to combined AD + VaD, in turn with a higher score than VaD, FTLD and other dementia disorders. Interrater agreement (weighted kappa;) for LC degeneration scoring was 0.83 - 0.91. DLB/ PDD, AD and AD + VaD were the diagnoses for 85% of the cases with macroscopic LC depigmentation. CONCLUSION: LC degeneration, which may be macroscopically noted, often indicates synuclein and/or Alzheimer pathology among demented. When clinical information is scarce or inconsistent, a macroscopic assessment of the LC may facilitate focusing of the subsequent neuropathological investigation. Also, the semiquantitative scoring system is a reliable tool for histological assessment of LC degeneration.
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Demência/patologia , Locus Cerúleo/patologia , Degeneração Neural/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/patologia , Demência Vascular/patologia , Feminino , Humanos , Doença por Corpos de Lewy/patologia , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/patologiaRESUMO
Allo-SCT is the only potentially curative regimen for myelodysplastic syndromes (MDSs), but it is associated with a high relapse risk. The role of chimerism analysis for prediction of relapse is yet to be determined. To assess the clinical usefulness of mixed chimerism (MC) for predicting hematological relapse, 75 consecutively transplanted patients with MDS were analyzed with regard to lineage-specific chimerism, encompassing CD33(+) cells in peripheral blood (PB, n=49) and CD34(+) cells in BM (n= 35). A cutoff of 5% recipient cells was used to discriminate complete donor chimerism from MC. A total of 19 patients (25%) experienced hematological relapse after a median of 5 (1-31) months. Sensitivity for detection of relapse was 59% for CD33(+) PB cells and 92% for CD34(+) BM cells with corresponding specificities of 91% and 65%. CD34(+) BM cells were analyzed before relapse in seven patients, five of whom showed MC at a median of 2.5 (0.5-7) months before relapse. In contrast, 8 of 18 patients showed MC involving CD33 PB with a median of one month (0.5-2) before relapse. Here, we provide a model for early detection of relapse after SCT in MDS, in which serial characterization of both CD33(+) PB cells and CD34(+) BM cells gives an opportunity for early treatment before overt relapse.
Assuntos
Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Síndromes Mielodisplásicas/cirurgia , Quimeras de Transplante/imunologia , Adolescente , Adulto , Idoso , Antígenos CD/sangue , Antígenos CD34/sangue , Antígenos de Diferenciação Mielomonocítica/sangue , Células Sanguíneas/imunologia , Células da Medula Óssea/imunologia , Criança , Pré-Escolar , Feminino , Transplante de Células-Tronco Hematopoéticas/mortalidade , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Prevenção Secundária , Sensibilidade e Especificidade , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico , Suécia/epidemiologia , Transplante HomólogoRESUMO
In recent years, Staphylococcus aureus has become a common bowel colonizer in Swedish infants. We aimed to identify host factors that determine such colonization. Stool samples from 100 Italian and 100 Swedish infants were obtained on seven occasions during the first year of life and cultured quantitatively for S. aureus. In a subgroup of infants in each cohort, individual strains were identified by random amplified polymorphic DNA analysis. Colonization at each time-point was related to delivery mode, siblings in family and antibiotic treatment. In total, 66% of the Italian and 78% of the Swedish infants had S. aureus in their stools on at least one time-point (p 0.08) and 4% of Italian and 27% of Swedish infants were positive on at least six of the seven time-points investigated (p 0.0001). Most infants analysed regarding strain carriage harboured a single strain in their microbiota for several months. The S. aureus stool populations in colonized infants decreased from 10(7) to 10(4) colony-forming units/g between 1 week and 1 year of age in both cohorts. In multivariate analysis, the strongest predictor for S. aureus colonization was being born in Sweden (OR 3.4 at 1 week of age, p 0.002). Having (an) elder sibling(s) increased colonization at peak phase (OR 1.8 at 6 months, p 0.047). Antibiotic treatment was more prevalent among Italian infants and correlated negatively with S. aureus colonization at 6 months of age (OR 0.3, p 0.01). To conclude, S. aureus is a more common gut colonizer in Swedish than Italian infants, a fact that could not be attributed to feeding or delivery mode.
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Portador Sadio/epidemiologia , Portador Sadio/microbiologia , Trato Gastrointestinal/microbiologia , Estilo de Vida , Staphylococcus aureus/isolamento & purificação , Animais , Antibacterianos/uso terapêutico , Estudos de Coortes , DNA Bacteriano/análise , DNA Bacteriano/genética , Feminino , Humanos , Lactente , Recém-Nascido , Itália , Masculino , Técnica de Amplificação ao Acaso de DNA Polimórfico , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Células-Tronco , SuéciaRESUMO
Isoproturon (N,N-dimethyl-N'-[4-(1-methylethyl)phenyl]urea), mecoprop (MCPP) (2-(4-chloro-2-methylphenoxy)propanoic acid) and acetochlor (2-chloro-N-(2-ethoxymethyl)-N-(2-ethyl-6-methylphenyl)acetamide) are agricultural pesticides that may leach through the vadose zone down to groundwater. Sediment samples were collected from intact sediment cores from 0 to 59 m below surface, including soil, unsaturated limestone and aquifer sand. In the unsaturated limestone, the initial pesticide concentrations (0.5-100 µg kg(-1)) did not systematically affect the proportion of mineralized pesticides or the kinetics. However, in the aquifer, mecoprop and to some degree isoproturon mineralization was found to increase with increasing initial concentration (0.5-100 µg L(-1) equivalent to 1-220 µg kg(-1)) demonstrating the importance of using environmentally relevant concentrations when predicting pesticide fate. The mineralization of isoproturon, mecoprop and acetochlor was studied in 40 samples at low concentrations (1-3 µg L(-1)) and specific pesticide-mineralizing bacteria were enumerated using 14C-MPN. Presence of the mineralizers documented a degradation potential of the pesticides within the catchment. The number of mineralizers varied from <0.18 to >16000 g(-1) and was not found to correlate with depth. Mecoprop, isoproturon and acetochlor were substantially mineralized in the soils (19-44% after 8months incubation at 1 µg kg(-1)), in sub-surface unsaturated limestone samples (≤2% for acetochlor, ≤21% for isoproturon and ≤31% for mecoprop) and in aquifer samples (4-28% for mecoprop, ≤4.7% for isoproturon and ≤5.6% for acetochlor). The finding of isoproturon and acetochlor mineralization in deep aquifers is novel and important for the evaluation of the fate of these pesticides, as even low mineralization rates can be important in aquifers exhibiting long residence times.
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Ácido 2-Metil-4-clorofenoxiacético/análogos & derivados , Herbicidas/química , Compostos de Fenilureia/química , Toluidinas/química , Poluentes Químicos da Água/química , Ácido 2-Metil-4-clorofenoxiacético/análise , Ácido 2-Metil-4-clorofenoxiacético/química , Carbonato de Cálcio/química , Monitoramento Ambiental , Água Doce/química , Sedimentos Geológicos/química , Herbicidas/análise , Cinética , Minerais/química , Compostos de Fenilureia/análise , Dióxido de Silício/química , Toluidinas/análise , Poluentes Químicos da Água/análiseRESUMO
Myelodysplastic syndromes (MDS) comprise a heterogeneous group of clonal stem-cell disorders characterized by ineffective hematopoiesis and risk of progression to acute myeloid leukemia. Increased apoptosis and suppressed functions of peripheral blood natural killer (NK) cells have been described in MDS patients, but only limited information is available on the phenotypic and functional integrity of NK cells in the bone marrow. In a cohort of 41 patients with distinct clinical subtypes of MDS, we here show that NK cells in the bone marrow show decreased surface expression of the activating receptors DNAM-1 and NKG2D. Notably, decreased receptor expression correlated with elevated bone marrow blast counts and was associated with impaired NK-cell responsiveness to stimulation with the K562 cell line, or co-activation by NKG2D or DNAM-1 in combination with the 2B4 receptor. Furthermore, antibody-masking experiments revealed a central role for DNAM-1 in NK cell-mediated killing of freshly isolated MDS blasts. Thus, given the emerging evidence for NK cell-mediated immune surveillance of neoplastic cells, we speculate that reduced expression of DNAM-1 on bone marrow NK cells may facilitate disease progression in patients with MDS.