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1.
bioRxiv ; 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38948755

RESUMO

Huntington's disease (HD), due to expansion of a CAG repeat in HTT , is representative of a growing number of disorders involving somatically unstable short tandem repeats. We find that overlapping and distinct genetic modifiers of clinical landmarks and somatic expansion in blood DNA reveal an underlying complexity and cell-type specificity to the mismatch repair-related processes that influence disease timing. Differential capture of non-DNA-repair gene modifiers by multiple measures of cognitive and motor dysfunction argues additionally for cell-type specificity of pathogenic processes. Beyond trans modifiers, differential effects are also illustrated at HTT by a 5'-UTR variant that promotes somatic expansion in blood without influencing clinical HD, while, even after correcting for uninterrupted CAG length, a synonymous sequence change at the end of the CAG repeat dramatically hastens onset of motor signs without increasing somatic expansion. Our findings are directly relevant to therapeutic suppression of somatic expansion in HD and related disorders and provide a route to define the individual neuronal cell types that contribute to different HD clinical phenotypes.

2.
Nat Commun ; 15(1): 3182, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38609352

RESUMO

Huntington's disease (HD) is a dominant neurological disorder caused by an expanded HTT exon 1 CAG repeat that lengthens huntingtin's polyglutamine tract. Lowering mutant huntingtin has been proposed for treating HD, but genetic modifiers implicate somatic CAG repeat expansion as the driver of onset. We find that branaplam and risdiplam, small molecule splice modulators that lower huntingtin by promoting HTT pseudoexon inclusion, also decrease expansion of an unstable HTT exon 1 CAG repeat in an engineered cell model. Targeted CRISPR-Cas9 editing shows this effect is not due to huntingtin lowering, pointing instead to pseudoexon inclusion in PMS1. Homozygous but not heterozygous inactivation of PMS1 also reduces CAG repeat expansion, supporting PMS1 as a genetic modifier of HD and a potential target for therapeutic intervention. Although splice modulation provides one strategy, genome-wide transcriptomics also emphasize consideration of cell-type specific effects and polymorphic variation at both target and off-target sites.


Assuntos
Doença de Huntington , Humanos , Doença de Huntington/genética , Éxons/genética , Perfilação da Expressão Gênica , Heterozigoto , Homozigoto , Proteínas MutL , Proteínas de Neoplasias
3.
Transplantation ; 108(7): e91-e105, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38587506

RESUMO

BACKGROUND: Despite ongoing improvements to regimens preventing allograft rejection, most cardiac and other organ grafts eventually succumb to chronic vasculopathy, interstitial fibrosis, or endothelial changes, and eventually graft failure. The events leading to chronic rejection are still poorly understood and the gut microbiota is a known driving force in immune dysfunction. We previously showed that gut microbiota dysbiosis profoundly influences the outcome of vascularized cardiac allografts and subsequently identified biomarker species associated with these differential graft outcomes. METHODS: In this study, we further detailed the multifaceted immunomodulatory properties of protolerogenic and proinflammatory bacterial species over time, using our clinically relevant model of allogenic heart transplantation. RESULTS: In addition to tracing longitudinal changes in the recipient gut microbiome over time, we observed that Bifidobacterium pseudolongum induced an early anti-inflammatory phenotype within 7 d, whereas Desulfovibrio desulfuricans resulted in a proinflammatory phenotype, defined by alterations in leukocyte distribution and lymph node (LN) structure. Indeed, in vitro results showed that B pseudolongum and D desulfuricans acted directly on primary innate immune cells. However, by 40 d after treatment, these 2 bacterial strains were associated with mixed effects in their impact on LN architecture and immune cell composition and loss of colonization within gut microbiota, despite protection of allografts from inflammation with B pseudolongum treatment. CONCLUSIONS: These dynamic effects suggest a critical role for early microbiota-triggered immunologic events such as innate immune cell engagement, T-cell differentiation, and LN architectural changes in the subsequent modulation of protolerant versus proinflammatory immune responses in organ transplant recipients.


Assuntos
Bifidobacterium , Microbioma Gastrointestinal , Rejeição de Enxerto , Transplante de Coração , Transplante de Coração/efeitos adversos , Microbioma Gastrointestinal/imunologia , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/microbiologia , Rejeição de Enxerto/prevenção & controle , Animais , Masculino , Fatores de Tempo , Sobrevivência de Enxerto , Disbiose , Camundongos Endogâmicos C57BL , Imunidade Inata , Imunomodulação , Fenótipo , Probióticos/uso terapêutico , Linfonodos/microbiologia , Linfonodos/imunologia
4.
Proc Natl Acad Sci U S A ; 121(16): e2322924121, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38607933

RESUMO

Many Mendelian disorders, such as Huntington's disease (HD) and spinocerebellar ataxias, arise from expansions of CAG trinucleotide repeats. Despite the clear genetic causes, additional genetic factors may influence the rate of those monogenic disorders. Notably, genome-wide association studies discovered somewhat expected modifiers, particularly mismatch repair genes involved in the CAG repeat instability, impacting age at onset of HD. Strikingly, FAN1, previously unrelated to repeat instability, produced the strongest HD modification signals. Diverse FAN1 haplotypes independently modify HD, with rare genetic variants diminishing DNA binding or nuclease activity of the FAN1 protein, hastening HD onset. However, the mechanism behind the frequent and the most significant onset-delaying FAN1 haplotype lacking missense variations has remained elusive. Here, we illustrated that a microRNA acting on 3'-UTR (untranslated region) SNP rs3512, rather than transcriptional regulation, is responsible for the significant FAN1 expression quantitative trait loci signal and allelic imbalance in FAN1 messenger ribonucleic acid (mRNA), accounting for the most significant and frequent onset-delaying modifier haplotype in HD. Specifically, miR-124-3p selectively targets the reference allele at rs3512, diminishing the stability of FAN1 mRNA harboring that allele and consequently reducing its levels. Subsequent validation analyses, including the use of antagomir and 3'-UTR reporter vectors with swapped alleles, confirmed the specificity of miR-124-3p at rs3512. Together, these findings indicate that the alternative allele at rs3512 renders the FAN1 mRNA less susceptible to miR-124-3p-mediated posttranscriptional regulation, resulting in increased FAN1 levels and a subsequent delay in HD onset by mitigating CAG repeat instability.


Assuntos
Doença de Huntington , MicroRNAs , Humanos , Regiões 3' não Traduzidas/genética , Endodesoxirribonucleases , Exodesoxirribonucleases/genética , Estudo de Associação Genômica Ampla , Doença de Huntington/genética , MicroRNAs/genética , Enzimas Multifuncionais
5.
Sleep ; 47(2)2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38109232

RESUMO

Individuals and society are dependent on transportation. Individuals move about their world for work, school, healthcare, social activities, religious and athletic events, and so much more. Society requires the movement of goods, food, medicine, etc. for basic needs, commerce, cultural and political exchanges, and all of its dynamic, complex elements. To meet these critical daily demands, the transportation system operates globally and around the clock. Regardless of their role, a basic requirement for the individuals operating the transportation system is that they are awake and at optimal alertness. This applies to individuals driving their own cars, riding a bike or motorcycle, as well as pilots of commercial aircraft, train engineers, long-haul truck drivers, and air traffic controllers. Alert operators are a basic requirement for a safe and effective transportation system. Decades of scientific and operational research have demonstrated that the 24/7 scheduling demands on operators and passengers of our transportation system create sleep and circadian disruptions that reduce alertness and performance and cause serious safety problems. These challenges underly the longstanding interest in transportation safety by the sleep and circadian scientific community. An area currently offering perhaps the most significant opportunities and challenges in transportation safety involves vehicle technology innovations. This paper provides an overview of these latest innovations with a focus on sleep-relevant issues and opportunities. Drowsy driving is discussed, along with fatigue management in round-the-clock transportation operations. Examples of cases where technology innovations could improve or complicate sleep issues are discussed, and ongoing sleep challenges and new safety opportunities are considered.


Assuntos
Condução de Veículo , Transtornos do Sono-Vigília , Humanos , Vigília , Tolerância ao Trabalho Programado , Fadiga , Sono , Transtornos do Sono-Vigília/complicações , Tecnologia , Acidentes de Trânsito
6.
Gut Microbes ; 15(2): 2291164, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38055306

RESUMO

Bifidobacterium is a widely distributed commensal bacterial genus that displays beneficial pro-homeostatic and anti-inflammatory immunomodulatory properties. Depletion or absence of Bifidobacterium in humans and model organisms is associated with autoimmune responses and impaired immune homeostasis. At the cellular level, Bifidobacterium upregulates suppressive regulatory T cells, maintains intestinal barrier function, modulates dendritic cell and macrophage activity, and dampens intestinal Th2 and Th17 programs. While there has been a large volume of literature characterizing the probiotic properties of various Bifidobacterial species, the likely multifactorial mechanisms underlying these effects remain elusive, in particular, its immune tolerogenic effect. However, recent work has shed light on Bifidobacterium surface structural polysaccharide and protein elements, as well as its metabolic products, as commensal mediators of immune homeostasis. This review aims to discuss several mechanisms Bifidobacterium utilizes for immune modulation as well as their indirect impact on the regulation of gut microbiome structure and function, from structural molecules to produced metabolites. These mechanisms are pertinent to an increasingly networked understanding of immune tolerance and homeostasis in health and disease.


Assuntos
Microbioma Gastrointestinal , Humanos , Tolerância Imunológica , Imunomodulação , Bifidobacterium , Homeostase
7.
bioRxiv ; 2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37547003

RESUMO

Huntington's disease (HD) is a dominantly inherited neurodegenerative disorder whose motor, cognitive, and behavioral manifestations are caused by an expanded, somatically unstable CAG repeat in the first exon of HTT that lengthens a polyglutamine tract in huntingtin. Genome-wide association studies (GWAS) have revealed DNA repair genes that influence the age-at-onset of HD and implicate somatic CAG repeat expansion as the primary driver of disease timing. To prevent the consequent neuronal damage, small molecule splice modulators (e.g., branaplam) that target HTT to reduce the levels of huntingtin are being investigated as potential HD therapeutics. We found that the effectiveness of the splice modulators can be influenced by genetic variants, both at HTT and other genes where they promote pseudoexon inclusion. Surprisingly, in a novel hTERT-immortalized retinal pigment epithelial cell (RPE1) model for assessing CAG repeat instability, these drugs also reduced the rate of HTT CAG expansion. We determined that the splice modulators also affect the expression of the mismatch repair gene PMS1, a known modifier of HD age-at-onset. Genome editing at specific HTT and PMS1 sequences using CRISPR-Cas9 nuclease confirmed that branaplam suppresses CAG expansion by promoting the inclusion of a pseudoexon in PMS1, making splice modulation of PMS1 a potential strategy for delaying HD onset. Comparison with another splice modulator, risdiplam, suggests that other genes affected by these splice modulators also influence CAG instability and might provide additional therapeutic targets.

9.
Respir Care ; 68(1): 52-59, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35705249

RESUMO

BACKGROUND: The evolution of compliance and driving pressure in ARDS and the effects of time spent on noninvasive respiratory support prior to intubation have not been well studied. We conducted this study to assess the effect of the duration of noninvasive respiratory support prior to intubation (ie, noninvasive ventilation [NIV], high-flow nasal cannula [HFNC], or a combination of NIV and HFNC) on static compliance and driving pressure and retrospectively describe its trajectory over time for COVID-19 and non-COVID-19 ARDS while on mechanical ventilation. METHODS: This is a retrospective analysis of prospectively collected data from one university-affiliated academic medical center, one rural magnet hospital, and 3 suburban community facilities. A total of 589 subjects were included: 55 COVID-19 positive, 137 culture positive, and 397 culture-negative subjects. Static compliance and driving pressure were calculated at each 8-h subject-ventilator assessment. RESULTS: Days of pre-intubation noninvasive respiratory support were associated with worse compliance and driving pressure but did not moderate any trajectory. COVID-19-positive subjects showed non-statistically significant worsening compliance by 0.08 units per subject-ventilator assessment (P = .24), whereas COVID-19-negative subjects who were either culture positive or negative showed statistically significant improvement (0.12 and 0.18, respectively; both P < .05); a statistically similar but inverse pattern was observed for driving pressure. CONCLUSIONS: In contrast to non-COVID-19 ARDS, COVID-19 ARDS was associated with a more ominous trajectory with no improvement in static compliance or driving pressures. Though there was no association between days of pre-intubation noninvasive respiratory support and mortality, its use was associated with worse overall compliance and driving pressure.


Assuntos
COVID-19 , Ventilação não Invasiva , Síndrome do Desconforto Respiratório , Insuficiência Respiratória , Humanos , Estudos Retrospectivos , COVID-19/complicações , Unidades de Terapia Intensiva , Respiração Artificial , Cânula , Insuficiência Respiratória/terapia , Oxigenoterapia
10.
Am J Hum Genet ; 109(5): 885-899, 2022 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-35325614

RESUMO

Genome-wide association studies (GWASs) of Huntington disease (HD) have identified six DNA maintenance gene loci (among others) as modifiers and implicated a two step-mechanism of pathogenesis: somatic instability of the causative HTT CAG repeat with subsequent triggering of neuronal damage. The largest studies have been limited to HD individuals with a rater-estimated age at motor onset. To capitalize on the wealth of phenotypic data in several large HD natural history studies, we have performed algorithmic prediction by using common motor and cognitive measures to predict age at other disease landmarks as additional phenotypes for GWASs. Combined with imputation with the Trans-Omics for Precision Medicine reference panel, predictions using integrated measures provided objective landmark phenotypes with greater power to detect most modifier loci. Importantly, substantial differences in the relative modifier signal across loci, highlighted by comparing common modifiers at MSH3 and FAN1, revealed that individual modifier effects can act preferentially in the motor or cognitive domains. Individual components of the DNA maintenance modifier mechanisms may therefore act differentially on the neuronal circuits underlying the corresponding clinical measures. In addition, we identified additional modifier effects at the PMS1 and PMS2 loci and implicated a potential second locus on chromosome 7. These findings indicate that broadened discovery and characterization of HD genetic modifiers based on additional quantitative or qualitative phenotypes offers not only the promise of in-human validated therapeutic targets but also a route to dissecting the mechanisms and cell types involved in both the somatic instability and toxicity components of HD pathogenesis.


Assuntos
Doença de Huntington , Cognição , DNA , Estudo de Associação Genômica Ampla , Humanos , Proteína Huntingtina/genética , Doença de Huntington/genética , Doença de Huntington/patologia , Expansão das Repetições de Trinucleotídeos
11.
Respir Med ; 190: 106599, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34788735

RESUMO

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a rapidly progressive interstitial lung disease with high mortality. Lung transplant remains a cornerstone of treatment despite the advent of antifibrotic therapy. In light of the increasing number of patients on antifibrotic therapy prior to lung transplantation it is paramount to demonstrate these medications do not augment postoperative complications following transplant. RESEARCH QUESTION: Does antifibrotic therapy increase perioperative complications and mortality in lung transplant recipients? STUDY DESIGN AND METHODS: We conducted a retrospective chart review of all patients actively listed for lung transplant at Temple University Hospital from June 2014 to April 2017 with a listing diagnosis of IPF. Subjects who received treatment with antifibrotic therapy (either pirfenidone or nintedanib) up until the time of lung transplantation were compared to subjects not on therapy. Data was collected regarding baseline demographics, pulmonary function tests, IPF exacerbations, perioperative bleeding and cardiac events, and outcomes in the postoperative period. RESULTS: A total of 94 subjects were included in the study: 42 subjects on antifibrotic therapy (28 pirfenidone, 14 nintedanib) and 52 subjects not on therapy in the pre-transplant period. Baseline characteristics were similar between study groups. Subjects treated with antifibrotic therapy pre-transplant were noted to have less FVC decline, fewer hospitalizations, and greater weight loss while on the transplant waiting list. No difference in post-transplant airway anastomosis complications, bleeding or mortality was observed between study groups. INTERPRETATION: Subjects with IPF on antifibrotic therapy prior to lung transplantation had better preservation of lung function in the pre-transplant period, and similar outcomes in the postoperative period compared to those not on antifibrotic therapy before lung transplant.


Assuntos
Antifibróticos/uso terapêutico , Fibrose Pulmonar Idiopática/tratamento farmacológico , Fibrose Pulmonar Idiopática/cirurgia , Transplante de Pulmão , Idoso , Feminino , Hospitalização , Humanos , Indóis/uso terapêutico , Masculino , Período Perioperatório , Piridonas/uso terapêutico , Estudos Retrospectivos , Capacidade Vital , Listas de Espera , Redução de Peso
12.
Curr Opin Organ Transplant ; 26(6): 567-581, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34714788

RESUMO

PURPOSE OF REVIEW: The microbiota plays an important role in health and disease. During organ transplantation, perturbations in microbiota influence transplant outcome. We review recent advances in characterizing microbiota and studies on regulation of intestinal epithelial barrier function and mucosal and systemic immunity by microbiota and their metabolites. We discuss implications of these interactions on transplant outcomes. RECENT FINDINGS: Metagenomic approaches have helped the research community identify beneficial and harmful organisms. Microbiota regulates intestinal epithelial functions. Signals released by epithelial cells or microbiota trigger pro-inflammatory or anti-inflammatory effects on innate and adaptive immune cells, influencing the structure and function of the immune system. Assessment and manipulation of microbiota can be used for biomarkers for diagnosis, prognosis, and therapy. SUMMARY: The bidirectional dialogue between the microbiota and immune system is a major influence on immunity. It can be targeted for biomarkers or therapy. Recent studies highlight a close association of transplant outcomes with microbiota, suggesting exciting potential avenues for management of host physiology and organ transplantation.


Assuntos
Microbiota , Transplante de Órgãos , Humanos , Intestinos , Transplante de Órgãos/efeitos adversos
13.
Drug Des Devel Ther ; 15: 331-338, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33536746

RESUMO

Asthma is a complex heterogeneous disease defined by chronic inflammation of the airways. Patients present with wheezing, chest tightness, cough and shortness of breath. Bronchial hyperresponsiveness and variable expiratory airflow limitation are hallmark features. About 3.6-6.1% of patients, despite receiving high-dose inhaled corticosteroids (ICS) and a second controller medication, report persistent symptoms referred to as severe asthma. Uncontrolled severe asthma is associated with increased mortality, morbidity, diminished quality of life and increased health expenditures. The development of modern biological therapy has revolutionized severe asthma treatment. By targeting specific chemokines, asthma control has drastically improved, resulting in better quality of life, less emergency department visits and inpatient admissions, and decreased chronic systemic corticosteroid utilization. Despite these advances, there remains a subset of asthma patients who remain symptomatic with poor quality of life and heavy utilization of the healthcare system. Recently attention has been given to pharmaceutical therapy directed at receptors and cytokines on the epithelial layer of the lung referred to as "alarmins". Thymic stromal lymphopoietin (TSLP) is an interleukin-7-like receptor family found on the epithelial layer of the lung that releases a cytokine cascade inducing eosinophilic inflammation, mucus production and airflow obstruction in asthmatics. Tezepelumab is the first investigational monoclonal antibody that inhibits TSLP. Proof of concept study and phase IIb studies demonstrated reduced asthma exacerbations, improvement in quality of life, less decline in FEV1 and decrease in biochemical inflammatory markers in comparison to placebo. It is presently undergoing three phase III studies and an additional phase II study.


Assuntos
Antiasmáticos/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Asma/tratamento farmacológico , Humanos , Índice de Gravidade de Doença
14.
Mol Reprod Dev ; 88(1): 3-14, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33251684

RESUMO

Multiplying the germline would increase the number of offspring that can be produced from selected animals, accelerating genetic improvement for livestock breeding. This could be achieved by producing multiple chimaeric animals, each carrying a mix of donor and host germ cells in their gonads. However, such chimaeric germlines would produce offspring from both donor and host genotypes, limiting the rate of genetic improvement. To resolve this problem, we disrupted the RNA-binding protein DAZL and generated germ cell-deficient host animals. Using Cas9-mediated homology-directed repair (HDR), we introduced a DAZL loss-of-function mutation in male ovine fetal fibroblasts. Following manual single cell isolation, 4/48 (8.3%) of donor cell strains were homozygously HDR-edited. Sequence-validated strains were used as nuclear donors for somatic cell cloning to generate three lambs, which died at birth. All DAZL null male neonatal sheep lacked germ cells on histological sections and showed greatly reduced germ cell markers. Somatic cells within their testes were morphologically intact and expressed normal levels of lineage-specific markers, suggesting that the germ cell niche remained intact. This extends the DAZL mutant phenotype beyond mice into agriculturally relevant ruminants, providing a pathway for using absolute germline transmitters in rapid livestock improvement.


Assuntos
Fibroblastos/metabolismo , Mutação com Perda de Função , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Ovinos/metabolismo , Espermatogônias/metabolismo , Testículo/metabolismo , Animais , Animais Geneticamente Modificados , Animais Recém-Nascidos , Sequência de Bases , Biomarcadores/metabolismo , Cruzamento/métodos , Células Cultivadas , Edição de Genes/métodos , Expressão Gênica , Masculino , Camundongos , Fenótipo , Reparo de DNA por Recombinação/genética , Ovinos/genética
15.
Respir Med Case Rep ; 31: 101227, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32983862

RESUMO

We report four individuals admitted for acute respiratory failure due to COVID-19 who demonstrated significant clinical improvement prior to discharge and subsequently were readmitted with worsening respiratory failure, elevated inflammatory markers and worsening chest imaging. We propose a multi-disciplinary discharge criterion to establish a safer discharge process including trending inflammatory markers, daily imaging and pursuing follow up CT chest, particularly in individuals with significant morbidities and health disparities.

16.
Infect Microbes Dis ; 2(4): 127-135, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38630076

RESUMO

Vibrio cholerae, the causative agent of the infectious disease, cholera, is commonly found in brackish waters and infects human hosts via the fecal-oral route. V. cholerae is a master of stress resistance as V. cholerae's dynamic lifestyle across different physical environments constantly exposes it to diverse stressful circumstances. Specifically, V. cholerae has dedicated genetic regulatory networks to sense different environmental cues and respond to these signals. With frequent outbreaks costing a tremendous amount of lives and increased global water temperatures providing more suitable aquatic habitats for V. cholerae, cholera pandemics remain a probable catastrophic threat to humanity. Understanding how V. cholerae copes with different environmental stresses broadens our repertoire of measures against infectious diseases and expands our general knowledge of prokaryotic stress responses. In this review, we summarize the regulatory mechanisms of how V. cholerae fights against stresses in vivo and in vitro.

17.
Ecol Evol ; 9(9): 5457-5467, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31110694

RESUMO

The impact of infectious diseases in natural ecosystems is strongly influenced by the degree of pathogen specialization and by the local assemblies of potential host species. This study investigated anther-smut disease, caused by fungi in the genus Microbotryum, among natural populations of plants in the Caryophyllaceae. A broad geographic survey focused on sites of the disease on multiple host species in sympatry. Analysis of molecular identities for the pathogens revealed that sympatric disease was most often due to co-occurrence of distinct, host-specific anther-smut fungi, rather than localized cross-species disease transmission. Flowers from sympatric populations showed that the Microbotryum spores were frequently moved between host species. Experimental inoculations to simulate cross-species exposure to the pathogens in these plant communities showed that the anther-smut pathogen was less able to cause disease on its regular host when following exposure of the plants to incompatible pathogens from another host species. These results indicate that multi-host/multi-pathogen communities are common in this system and they involve a previously hidden mechanism of interference between Microbotryum fungi, which likely affects both pathogen and host distributions.

18.
EPJ Data Sci ; 7(1): 39, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30956929

RESUMO

Fast-food outlets play a significant role in the nutrition of British children who get more food from such shops than the school canteen. To reduce young people's access to fast-food meals during the school day, many British cities are implementing zoning policies. For instance, cities can create buffers around schools, and some have used 200 meters buffers while others used 400 meters. But how close is too close? Using the road network is needed to precisely computing the distance between fast-food outlets (for policies limiting the concentration), or fast-food outlets and the closest school (for policies using buffers). This estimates how much of the fast-food landscape could be affected by a policy, and complementary analyses of food utilization can later translate the estimate into changes on childhood nutrition and obesity. Network analyses of retail and urban forms are typically limited to the scale of a city. However, to design national zoning policies, we need to perform this analysis at a national scale. Our study is the first to perform a nation-wide analysis, by linking large datasets (e.g., all roads, fast-food outlets and schools) and performing the analysis over a high performance computing cluster. We found a strong spatial clustering of fast-food outlets (with 80% of outlets being within 120 of another outlet), but much less clustering for schools. Results depend on whether we use the road network on the Euclidean distance (i.e. 'as the crow flies'): for instance, half of the fast-food outlets are found within 240 m of a school using an Euclidean distance, but only one-third at the same distance with the road network. Our findings are consistent across levels of deprivation, which is important to set equitable national policies. In line with previous studies (at the city scale rather than national scale), we also examined the relation between centrality and outlets, as a potential target for policies, but we found no correlation when using closeness or betweenness centrality with either the Spearman or Pearson correlation methods.

19.
J Am Acad Dermatol ; 67(5): 962-8, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22325461

RESUMO

BACKGROUND: Chronic hepatitis C virus (HCV) infection is associated with necrolytic acral erythema (NAE). However, the prevalence of NAE among patients with HCV is unknown, and the clinical and histologic features have not been well defined. OBJECTIVE: We sought to determine the prevalence, overall clinical features, and cutaneous histopathological characteristics of patients with NAE. METHODS: A cross-sectional study was performed among patients with chronic HCV infection cared for at 3 Philadelphia hospitals. Patients completed a questionnaire and underwent a dermatologic examination. All undiagnosed skin lesions with clinical features of NAE as described in the literature underwent skin biopsy. RESULTS: Among 300 patients with chronic HCV infection (median age 55 years; 73% male; 70% HCV genotype 1), 5 of them (prevalence 1.7%; 95% confidence interval 0.5%-3.8%) had skin lesions consistent with NAE clinically, which were analyzed and confirmed with skin biopsy specimen. All 5 skin biopsy specimens demonstrated variable psoriasiform hyperplasia, mild papillomatosis, parakeratosis, and necrotic keratinocytes in the superficial epidermis. All 5 patients were older than 40 years, were African American men, were infected with HCV genotype 1, and had a high viral load (>200,000 IU/mL). LIMITATIONS: Previous descriptions of NAE were used to guide the evaluation and need for a biopsy; however, other unknown clinical characteristics of the disease may exist. The senior author was the sole interpreter of the biopsy specimens. Only 300 of the 2500 eligible patients enrolled in the study. CONCLUSION: The prevalence of NAE among patients with chronic HCV in this sample was very low. Further research is needed to determine the origin and appropriate therapies of NAE.


Assuntos
Eritema/epidemiologia , Hepatite C Crônica/epidemiologia , Clobetasol/uso terapêutico , Estudos Transversais , Eritema/patologia , Feminino , Glucocorticoides/uso terapêutico , Hepatite C Crônica/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Terapia PUVA , Prevalência , Estudos Prospectivos
20.
Indian J Med Res ; 100: 272-6, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7829166

RESUMO

This study reports the production of a rabbit polyclonal antibody to myeloperoxidase (MPO) and its use in ascertaining the myeloid lineage of blasts in leukaemia. Comparison of the immunocytochemical stain using the anti-MPO antibody with the routine cytochemical methodology showed that the former was more sensitive. In all subtypes of acute myeloid leukaemia (AML; 72 patients, M1-M6) greater number of MPO positive blast cells were observed by immunocytochemistry, the highest being in the promyelocytic leukaemia. It was also extremely specific for cells of the myeloid lineage as it did not react with blasts from acute lymphoblastic (50 patients) and megakaryoblastic leukaemias (1 patient). In addition, it proved most useful for the lineage determination of blasts from patients with undifferentiated acute leukaemias (AUL) and those with chronic myeloid leukaemia in blast crisis (CML-BC). Out of 8 patients of AULs, 6 were classified as acute myeloblastic leukaemia due to their reactivity to the anti-MPO antibody. Similarly, out of 12 patients of chronic myeloid leukaemia in blast crisis, blasts from 8 showed reactivity to this antibody and thus could be identified as belonging to the myeloid lineage and/or of the mixed blast crisis type.


Assuntos
Crise Blástica/diagnóstico , Peroxidase/imunologia , Humanos , Leucemia Mieloide Aguda/patologia
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