RESUMO
INTRODUCTION: The neurofibromatoses (NF) are a group of rare, genetic diseases sharing a predisposition to develop multiple benign nervous system tumors. Given the wide range of NF symptoms and medical specialties involved in NF care, we sought to evaluate the level of awareness of, and agreement with, published NF clinical guidelines among NF specialists in the United States. METHODS: An anonymous, cross-sectional, online survey was distributed to U.S.-based NF clinicians. Respondents self-reported demographics, practice characteristics, awareness of seven NF guideline publications, and level of agreement with up to 40 individual recommendations using a 5-point Likert scale. We calculated the proportion of recommendations that each clinician rated "strongly agree", and assessed for differences in guideline awareness and agreement by respondent characteristics. RESULTS: Sixty-three clinicians (49% female; 80% academic practice) across > 8 medical specialties completed the survey. Awareness of each guideline publication ranged from 53%-79% of respondents; specialists had higher awareness of publications endorsed by their medical professional organization (p < 0.05). The proportion of respondents who "strongly agree" with individual recommendations ranged from 17%-83%; for 16 guidelines, less than 50% of respondents "strongly agree". There were no significant differences in overall agreement with recommendations based on clinicians' gender, race, specialty, years in practice, practice type (academic/private practice/other), practice location (urban/suburban/rural), or involvement in NF research (p > 0.05 for all). CONCLUSIONS: We identified wide variability in both awareness of, and agreement with, published NF care guidelines among NF experts. Future quality improvement efforts should focus on evidence-based, consensus-driven methods to update and disseminate guidelines across this multi-specialty group of providers. Patients and caregivers should also be consulted to proactively anticipate barriers to accessing and implementing guideline-driven care. These recommendations for improving guideline knowledge and adoption may also be useful for other rare diseases requiring multi-specialty care coordination.
Assuntos
Neurofibromatoses , Neurofibromatose 1 , Estudos Transversais , Feminino , Humanos , Masculino , Neurofibromatose 1/patologia , Melhoria de Qualidade , Doenças Raras , Estados UnidosRESUMO
PURPOSE: The coronavirus disease 2019 (COVID-19) pandemic has had unprecedented impact on the provision of medical care for genetic disorders. The purpose of this study was to assess the effects of the pandemic on neurofibromatosis (NF) care and research. METHODS: Sixty-three United States NF clinics were surveyed to identify the impact of the pandemic on clinician role, patient volume, continuity of guideline-driven surveillance, research protocols, and use of (and satisfaction with) telehealth for the delivery of NF care. RESULTS: Fifty-two clinic directors or their representatives completed the survey (83% response rate). About 2/3 of the clinics reported a greater than 50% decrease in the number of available patient appointments, and modified clinical surveillance and research protocols. Fifty-one clinics (98%) newly instituted telehealth during the pandemic. Barriers to telehealth prior to the pandemic were insurance reimbursement concerns and lack of infrastructure. Since telehealth was initiated, high provider satisfaction was reported with ease of use. The most common area of concern was related to inability to perform a physical examination. CONCLUSION: Results show marked impacts on NF care and research since the beginning of the pandemic, with potential long-term changes related to the introduction (or adoption) of telehealth for clinical care.
Assuntos
COVID-19/epidemiologia , Neurofibromatoses/epidemiologia , SARS-CoV-2/patogenicidade , Telemedicina/métodos , Humanos , Pandemias/estatística & dados numéricos , Satisfação do Paciente , Doenças Raras , Estados UnidosRESUMO
Neurofibromatosis type 1 (NF1) is a rare genetic disorder, characterized by the development of benign and malignant nerve tumors. Although all individuals with NF1 harbor genetic alterations in the same gene, the clinical manifestations of NF1 are extremely heterogeneous even among individuals who carry identical genetic defects. In order to deepen the understanding of phenotypic manifestations in NF1, we comprehensively characterized the prevalence of 18 phenotypic traits in 2051 adults with NF1 from the Children's Tumor Foundation's NF1 registry. We further investigated the coassociation of traits and found positive correlations between spinal neurofibromas and pain, spinal neurofibromas and scoliosis, spinal neurofibromas and optic gliomas, and optic gliomas and sphenoid wing dysplasia. Furthermore, with increasing numbers of cutaneous neurofibromas, the odds ratio of malignant peripheral nerve sheath tumor increased. Phenotypic clustering revealed 6 phenotypic patient cluster subtypes: mild, freckling predominant, neurofibroma predominant, skeletal predominant, late-onset neural severe, and early-onset neural severe, highlighting potential phenotypic subtypes within NF1. Together, our results support potential shared molecular pathogenesis for certain clinical manifestations and illustrate the utility of disease registries for understanding rare diseases.
Assuntos
Neurofibromatose 1/etiologia , Adolescente , Adulto , Idoso , Comorbidade , Humanos , Pessoa de Meia-Idade , Mutação , Neurofibromatose 1/epidemiologia , Neurofibromina 1/genética , Fenótipo , Prevalência , Sistema de Registros , Adulto JovemRESUMO
Early-phase clinical trials using oral inhibitors of MEK, the mitogen-activated protein kinase kinase, have demonstrated benefit for patients with neurofibromatosis type 1 (NF1)-associated tumors, particularly progressive low-grade gliomas and plexiform neurofibromas. Given this potential of MEK inhibition as an effective medical therapy, the use of targeted agents in the NF1 population is likely to increase substantially. For clinicians with limited experience prescribing MEK inhibitors, concern about managing these treatments may be a barrier to use. In this manuscript, the Clinical Care Advisory Board of the Children's Tumor Foundation reviews the published experience with MEK inhibitors in NF1 and outlines recommendations for side-effect management, as well as monitoring guidelines. These recommendations can serve as a beginning framework for NF providers seeking to provide the most effective treatments for their patients. IMPLICATIONS FOR PRACTICE: Neurofibromatosis type 1 (NF1) clinical care is on the cusp of a transformative shift. With the success of recent clinical trials using MEK inhibitors, an increasing number of NF1 patients are being treated with MEK inhibitors for both plexiform neurofibromas and low-grade gliomas. The use of MEK inhibitors is likely to increase substantially in NF1. Given these changes, the Clinical Care Advisory Board of the Children's Tumor Foundation has identified a need within the NF1 clinical community for guidance for the safe and effective use of MEK inhibitors for NF1-related tumors. This article provides a review of the published experience of MEK inhibitors in NF1 and provides recommendations for monitoring and management of side effects.
Assuntos
Antineoplásicos , Neurofibroma Plexiforme , Neurofibromatose 1 , Antineoplásicos/uso terapêutico , Criança , Humanos , Quinases de Proteína Quinase Ativadas por Mitógeno , Neurofibroma Plexiforme/tratamento farmacológico , Neurofibromatose 1/tratamento farmacológico , Inibidores de Proteínas Quinases/efeitos adversosRESUMO
BACKGROUND: Our primary aim was to assess the ability of a non-profit foundation-sponsored clinic network to facilitate access to specialized care for patients with neurofibromatoses (NF), a group of neurogenetic disorders including NF1, NF2, and schwannomatosis (SWN). Our secondary aim was to identify how our findings in NF could be applied more broadly to other rare diseases. METHODS: We retrospectively reviewed aggregate data on patient volume reported by specialty NF clinics in a nonprofit network from 2008 to 2015. We classified clinics as high or low volume for disease type (NF1 and NF2/schwannomatosis) and pediatric/adult care. We compared clinic-level data to self-reported patient-level data from a large online patient registry. RESULTS: Between 2008 and 2015, the number of certified NF clinics grew from 32 to 50, and annual patient volume rose from 6776 to 10,245 patients (13% of the total estimated U.S. NF patient population). For patient registry participants (n = 4476), the median driving distance to the nearest network clinic was 51.3 miles. Driving distances to reach high-volume centers were elevated for adults compared to children (295.8 vs. 67.9 miles), and schwannomatosis and NF2 patients compared to NF1 patients (310.9 vs. 368.1 vs. 161.7 miles). Of registry participants reporting their location of care (n = 2271), only 43.2% received care in a network specialty clinic, with especially low rates of attendance in the Southwest and Far West. CONCLUSIONS: While the number of certified NF clinics and volume of patients seen in these clinics has increased, many NF patients still do not attend specialty clinics and/or travel a significant distance for care. Geographic access to care is more limited for adults, patients with rarer conditions, and patients in the Western U.S. Potential measures to improve access to specialty care for people living with NF and other rare diseases are discussed.
Assuntos
Assistência Ambulatorial/normas , Acessibilidade aos Serviços de Saúde/normas , Neurilemoma/terapia , Neurofibromatoses/terapia , Neurofibromatose 1/terapia , Neurofibromatose 2/terapia , Doenças Raras/terapia , Neoplasias Cutâneas/terapia , Adolescente , Adulto , Distribuição por Idade , Idoso , Instituições de Assistência Ambulatorial/estatística & dados numéricos , Condução de Veículo/estatística & dados numéricos , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Organizações sem Fins Lucrativos , Características de Residência/estatística & dados numéricos , Estudos Retrospectivos , Autorrelato , Viagem/estatística & dados numéricos , Estados Unidos , Adulto JovemRESUMO
Cutaneous neurofibromas (cNF) are a nearly ubiquitous symptom of neurofibromatosis type 1 (NF1), a disorder with a broad phenotypic spectrum caused by germline mutation of the neurofibromatosis type 1 tumour suppressor gene (NF1). Symptoms of NF1 can include learning disabilities, bone abnormalities and predisposition to tumours such as cNFs, plexiform neurofibromas, malignant peripheral nerve sheath tumours and optic nerve tumours. There are no therapies currently approved for cNFs aside from elective surgery, and the molecular aetiology of cNF remains relatively uncharacterised. Furthermore, whereas the biallelic inactivation of NF1 in neoplastic Schwann cells is critical for cNF formation, it is still unclear which additional genetic, transcriptional, epigenetic, microenvironmental or endocrine changes are important. Significant inroads have been made into cNF understanding, including NF1 genotype-phenotype correlations in NF1 microdeletion patients, the identification of recurring somatic mutations, studies of cNF-invading mast cells and macrophages, and clinical trials of putative therapeutic targets such as mTOR, MEK and c-KIT. Despite these advances, several gaps remain in our knowledge of the associated pathogenesis, which is further hampered by a lack of translationally relevant animal models. Some of these questions may be addressed in part by the adoption of genomic analysis techniques. Understanding the aetiology of cNF at the genomic level may assist in the development of new therapies for cNF, and may also contribute to a greater understanding of NF1/RAS signalling in cancers beyond those associated with NF1. Here, we summarise the present understanding of cNF biology, including the pathogenesis, mutational landscape, contribution of the tumour microenvironment and endocrine signalling, and the historical and current state of clinical trials for cNF. We also highlight open access data resources and potential avenues for future research that leverage recently developed genomics-based methods in cancer research.
Assuntos
Neurofibromatoses/genética , Neoplasias Cutâneas/genética , Animais , Genes da Neurofibromatose 1 , Genômica , Humanos , Mutação , Neurofibromatoses/metabolismo , Neurofibromatoses/patologia , Neurofibromatose 1/genética , Neurofibromatose 1/patologia , Neurofibromina 1/genética , Neurofibromina 1/metabolismo , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologiaRESUMO
OBJECTIVE: The main objective of this study was to determine if family history of malignant peripheral nerve sheath tumor (MPNST) increases risk of developing an MPNST in patients with neurofibromatosis-1 (NF-1). MATERIALS AND METHODS: Individuals with NF-1 registered with the Children's Tumor Foundation's Neurofibromatosis Registry were emailed an anonymous 15-minute survey with regard to personal and family history of NF-1, MPNST, ages of onset, and symptomatology. Participation was voluntary and information was self-reported. RESULTS: The survey was sent to 4801 registrants, 878 responded. Presence of a family history of MPNST was found to be a risk factor for the development of MPNST; 19.4% of respondents confirming a family history of MPNST developed MPNST compared with 7.5% of respondents with no family history (odds ratio, 2.975; 95% confidence interval, 1.232-7.187; P=0.021). NF-1 patients with a positive family history developed MPNST at a younger age than those with no family history (8.3% vs. 0.5% P=0.003 and 13.9% vs. 2.4% P=0.003, for onset before 10 and 20, respectively). In the MPNST population with a known family history, onset prior to age 10 was significantly more prevalent (42.9% vs. 7% P=0.029). CONCLUSIONS: These results suggest a positive family history of MPNST represents a risk factor for the development and early onset of MPNST in individuals with NF-1.
Assuntos
Família , Neurofibromatose 1 , Neurofibrossarcoma , Sistema de Registros , Adolescente , Adulto , Idade de Início , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Anamnese , Pessoa de Meia-Idade , Neurofibromatose 1/epidemiologia , Neurofibromatose 1/genética , Neurofibromatose 1/patologia , Neurofibrossarcoma/epidemiologia , Neurofibrossarcoma/genética , Neurofibrossarcoma/patologia , Fatores de RiscoRESUMO
The neurofibromatoses (neurofibromatosis type 1, neurofibromatosis type 2 and schwannomatosis) are rare disorders having clinical manifestations that vary greatly from patient to patient. The rarity and variability of these disorders has made it challenging for investigators to identify sufficient numbers of patients with particular clinical characteristics or specific germline mutations for participation in interventional studies. Similarly, because the natural history of all types of neurofibromatosis (NF) is variable and unique for each individual, it is difficult to identify meaningful clinical outcome measures for potential therapeutic interventions. In 2012, the Children's Tumor Foundation created a web-based patient-entered database, the NF Registry, to inform patients of research opportunities for which they fit general eligibility criteria and enable patients to contact investigators who are seeking to enroll patients in approved trials. Registrants were recruited through CTF-affiliated NF clinics and conferences, through its website, and by word-of-mouth and social media. Following online consent, demographic information and details regarding manifestations of NF were solicited on the Registry website. Statistical analyses were performed on data from a cohort of 4680 registrants (the number of registrants as of October 9, 2015) who met diagnostic criteria for one of the 3 NF conditions. The analyses support our hypothesis that patient-reported symptom incidences in the NF Registry are congruent with published clinician-sourced data. Between April 26, 2013 and July 8, 2016, the registry has been useful to investigators in recruitment, particularly for observational trials, especially those for development of patient-reported outcomes.
Assuntos
Internet , Neurofibromatoses , Sistema de Registros , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Pesquisa Biomédica/métodos , Criança , Pré-Escolar , Ensaios Clínicos como Assunto , Confidencialidade , Curadoria de Dados , Feminino , Humanos , Lactente , Internacionalidade , Masculino , Pessoa de Meia-Idade , Neurofibromatoses/epidemiologia , Participação do Paciente , Controle de Qualidade , Inquéritos e Questionários , Adulto JovemRESUMO
Neurofibromatosis type 1 (NF1) is a genetic disorder with a range of clinical manifestations such as widespread growth of benign tumours called neurofibromas, pain, learning disorders, bone deformities, vascular abnormalities and even malignant tumours. With the establishment of the Children's Tumour Foundation biobank, neurofibroma samples can now be collected directly from patients to be analysed by the larger scientific community. This work describes a pilot study to characterize one class of neurofibroma, cutaneous neurofibromas, by molecularly profiling of ~40 cutaneous neurofibromas collected from 11 individual patients. Data collected from each tumour includes (1) SNP Arrays, (2) Whole genome sequencing (WGS) and (3) RNA-Sequencing. These data are now freely available for further analysis at http://www.synapse.org/cutaneousNF.
Assuntos
Neurofibroma , Neoplasias Cutâneas , DNA de Neoplasias , Humanos , Análise em Microsséries , Neurofibroma/genética , Neurofibroma/metabolismo , Projetos Piloto , Análise de Sequência de RNA , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/metabolismoRESUMO
The neurofibromatoses (NF) are a group of rare genetic disorders that can affect all races equally at an incidence from 1:3000 (NF1) to a log unit lower for NF2 and schwannomatosis. Since the research community is reporting an increasing number of malignant cancers that carry mutations in the NF genes, the general interest of both the research and pharma community is increasing and the authors saw an opportunity to present a novel, fresh approach to drug discovery in NF. The aim of the paper is to challenge the current drug discovery approach to NF, whereby existing targeted therapies that are either in the clinic or on the market for other disease indications are repurposed for NF. We offer a suggestion for an alternative drug discovery approach. In the new approach, selective and tolerable targeted therapies would be developed for NF and later expanded to patients with more complex diseases such as malignant cancer in which the NF downstream pathways are deregulated. The Children's Tumor Foundation, together with some other major NF funders, is playing a key role in funding critical initiatives that will accelerate the development of better targeted therapies for NF patients, while these novel, innovative treatments could potentially be beneficial to molecularly characterized cancer patients in which NF mutations have been identified.
Assuntos
Ensaios Clínicos como Assunto/organização & administração , Descoberta de Drogas/tendências , Medicina Baseada em Evidências/tendências , Predisposição Genética para Doença/genética , Neurofibromatoses/tratamento farmacológico , Neurofibromatoses/genética , Humanos , Resultado do TratamentoRESUMO
OBJECTIVE: Clinically validated biomarkers for neurofibromatosis 1 (NF1), neurofibromatosis 2 (NF2), and schwannomatosis (SWN) have not been identified to date. The biomarker working group's goals are to (1) define biomarker needs in NF1, NF2, and SWN; (2) summarize existing data on biomarkers in NF1, NF2, and SWN; (3) outline recommendations for sample collection and biomarker development; and (4) standardize sample collection and methodology protocols where possible to promote comparison between studies by publishing standard operating procedures (SOPs). METHODS: The biomarker group reviewed published data on biomarkers in NF1, NF2, and SWN and on biobanking efforts outside these diseases via literature search, defined the need for biomarkers in NF, and developed recommendations in a series of consensus meetings. RESULTS: We describe existing biomarkers in NF and report consensus recommendations for SOP and a minimal clinical dataset to accompany samples derived from patients with NF1, NF2, and SWN in decentralized biobanks. CONCLUSIONS: These recommendations are intended to provide clinicians and researchers with a common set of guidelines to collect and store biospecimens and for establishment of biobanks for NF1, NF2, and SWN.
Assuntos
Bancos de Espécimes Biológicos , Biomarcadores , Neurilemoma/metabolismo , Neurofibromatoses/metabolismo , Neurofibromatose 1/metabolismo , Neurofibromatose 2/metabolismo , Neoplasias Cutâneas/metabolismo , Biomarcadores/metabolismo , Conjuntos de Dados como Assunto , Humanos , Neurilemoma/diagnóstico , Neurofibromatoses/diagnóstico , Neurofibromatose 1/diagnóstico , Neurofibromatose 2/diagnóstico , Neoplasias Cutâneas/diagnósticoRESUMO
BACKGROUND: The abomasal helminth Teladorsagia circumcincta is one of the most economically important parasites affecting sheep in temperate regions. Infection is particularly detrimental to lambs, in which it can cause pronounced morbidity and severe production losses. Due to the spreading resistance of this parasite to all classes of anthelmintic drugs, teladorsagiosis is having an increasingly severe impact on the sheep industry with significant implications for sheep welfare. Protective immunity develops slowly, wanes rapidly and does not appear to be as effective in young lambs. To investigate the development of immunity to T. circumcincta in sheep and lambs, we used cytokine transcript profiling to examine differences in the abomasal mucosa and gastric lymph node of naïve and previously infected sheep and lambs following challenge. RESULTS: The results of these experiments demonstrated that the abomasal mucosa is a major source of cytokines during abomasal helminth infection. A local Th2-type cytokine response was observed in the abomasal mucosa and gastric lymph node of the previously infected sheep and lambs when compared with those of the naïve during the early stages of infection. In contrast, a pro-inflammatory component more was evident in the abomasal mucosa and gastric lymph node of the naïve sheep when compared with those of the previously infected, which was not observed in the lambs. CONCLUSIONS: The greater levels of Th2-type cytokine transcripts in both the abomasum and gastric lymph node of the previously infected compared with naïve sheep and lambs emphasises the importance of these mechanisms in the immune response to T. circumcincta infection. Younger lambs appear to be able to generate similar Th2-type responses in the abomasum suggesting that the increased morbidity and apparent lack of resistance in younger lambs following continuous or repeated exposure to T. circumcincta is unlikely to be due to a lack of appropriate Th2-type cytokine production.
Assuntos
Citocinas/fisiologia , Ostertagia , Ostertagíase/veterinária , Doenças dos Ovinos/parasitologia , Abomaso/parasitologia , Animais , Animais Recém-Nascidos/imunologia , Animais Recém-Nascidos/parasitologia , Animais Recém-Nascidos/fisiologia , Contagem de Células/veterinária , Citocinas/biossíntese , Mastócitos/fisiologia , Ostertagíase/imunologia , Ovinos/parasitologia , Doenças dos Ovinos/imunologia , Transcrição GênicaRESUMO
Continual low-level exposure of sheep to the helminth Teladorsagia circumcincta elicits a temporary protective immunity, where factors in the immune abomasal mucosa prevent penetration of infective larvae, but which is essentially lost within 6 weeks of cessation of parasite challenge. Here, a proteomic approach was used to identify proteins that are differentially regulated in immune compared to naïve sheep, as potential key mediators of immunity. Six naïve sheep and 12 sheep trickle-infected with T. circumcincta were treated with anthelmintic, and the naïve (control) and 6 immune sheep were killed 7 days later. The remaining 6 sheep (immune waning) were killed 42 days after anthelmintic treatment. Abomasal tissue samples were subjected to 2D-gel electrophoresis and densitometric analysis. Selected spots (n=73) were identified by peptide mass fingerprinting and confirmatory Western blotting was carried out for 10 proteins. Spots selectively up-regulated in immune versus control, but not immune waning versus control sheep, included galectin-15 and thioredoxin, which were confirmed by Western blotting. In immune sheep, serum albumin was significantly down-regulated and albumin proteolytic cleavage fragments were increased compared to controls. Unexpectedly, albumin mRNA was relatively highly expressed in control mucosa, down-regulated in immune, and was immunolocalized to mucus-producing epithelial cells. Thus we have identified differential expression of a number of proteins following T. circumcincta trickle infection that may play a role in host protection and inhibition of parasite establishment.
Assuntos
Abomaso/metabolismo , Proteínas de Helminto/metabolismo , Doenças dos Ovinos/metabolismo , Trichostrongyloidea , Tricostrongiloidíase/veterinária , Abomaso/efeitos dos fármacos , Abomaso/imunologia , Imunidade Adaptativa , Animais , Anti-Helmínticos/administração & dosagem , Western Blotting , Eletroforese em Gel Bidimensional , Galectinas/genética , Galectinas/metabolismo , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/imunologia , Mucosa Gástrica/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Proteínas de Helminto/genética , Proteômica , RNA Mensageiro/metabolismo , Albumina Sérica/genética , Albumina Sérica/metabolismo , Ovinos , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/imunologia , Carneiro Doméstico , Tiorredoxinas/genética , Tiorredoxinas/metabolismo , Tricostrongiloidíase/tratamento farmacológico , Tricostrongiloidíase/imunologia , Tricostrongiloidíase/metabolismoRESUMO
Infection of sheep with the gastric nematode Teladorsagia circumcincta results in distinct Th2-type changes in the mucosa, including mucous neck cell and mast cell hyperplasia, eosinophilia, recruitment of IgA/IgE producing cells and neutrophils, altered T-cell subsets and mucosal hypertrophy. To address the protective mechanisms generated in animals on previous exposure to this parasite, gene expression profiling was carried out using samples of abomasal mucosa collected pre- and post- challenge from animals of differing immune status, using an experimental model of T. circumcincta infection. Recently developed ovine cDNA arrays were used to compare the abomasal responses of sheep immunised by trickle infection with worm-naïve sheep, following a single oral challenge of 50 000 T. circumcincta L3. Key changes were validated using qRT-PCR techniques. Immune animals demonstrated highly significant increases in levels of transcripts normally associated with cytotoxicity such as granulysin and granzymes A, B and H, as well as mucous-cell derived transcripts, predominantly calcium-activated chloride channel 1 (CLCA1). Challenge infection also induced up-regulation of transcripts potentially involved in initiating or modulating the immune response, such as heat shock proteins, complement factors and the chemokine CCL2. In contrast, there was marked infection-associated down-regulation of gene expression of members of the gastric lysozyme family. The changes in gene expression levels described here may reflect roles in direct anti-parasitic effects, immuno-modulation or tissue repair.
Assuntos
Abomaso/metabolismo , Regulação da Expressão Gênica , Mucosa Intestinal/metabolismo , Doenças dos Ovinos/genética , Trichostrongyloidea/fisiologia , Tricostrongiloidíase/veterinária , Abomaso/parasitologia , Animais , Etiquetas de Sequências Expressas , Perfilação da Expressão Gênica/veterinária , Mucosa Intestinal/parasitologia , Dados de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos/veterinária , Reação em Cadeia da Polimerase/veterinária , Análise de Sequência de DNA/veterinária , Ovinos , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/parasitologia , Tricostrongiloidíase/imunologia , Tricostrongiloidíase/metabolismo , Tricostrongiloidíase/parasitologiaRESUMO
BACKGROUND: C57BL/6J mice possess a single intelectin (Itln) gene on chromosome 1. The function of intelectins is not well understood, but roles have been postulated in insulin sensitivity, bacterial recognition, intestinal lactoferrin uptake and response to parasites and allergens. In contrast to C57BL/6J mice, there is evidence for expansion of the Itln locus in other strains and at least one additional mouse Itln gene product has been described. The aim of this study was to sequence and characterise the Itln locus in the 129S7 strain, to determine the nature of the chromosomal expansion and to inform possible future gene deletion strategies. RESULTS: Six 129S7 BAC clones were sequenced and assembled to generate 600 kbp of chromosomal sequence, including the entire Itln locus of approximately 500 kbp. The locus contained six distinct Itln genes, two CD244 genes and several Itln- and CD244-related pseudogenes. It was approximately 433 kbp larger than the corresponding C57BL/6J locus. The expansion of the Itln locus appears to have occurred through multiple duplications of a segment consisting of a full-length Itln gene, a CD244 (pseudo)gene and an Itln pseudogene fragment. Strong evidence for tissue-specific distribution of Itln variants was found, indicating that Itln duplication contributes more than a simple gene dosage effect. CONCLUSIONS: We have characterised the Itln locus in 129S7 mice to reveal six Itln genes with distinct sequence and expression characteristics. Since C57BL/6J mice possess only a single Itln gene, this is likely to contribute to functional differences between C57BL/6J and other mouse strains.
Assuntos
Dosagem de Genes , Loci Gênicos , Lectinas/genética , Animais , Antígenos CD/genética , Sequência de Bases , Sítios de Ligação , Cromossomos Artificiais Bacterianos , Cromossomos de Mamíferos/genética , Evolução Molecular , Biblioteca Gênica , Genômica , Proteínas de Homeodomínio/metabolismo , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Anotação de Sequência Molecular , Dados de Sequência Molecular , Filogenia , Regiões Promotoras Genéticas , Pseudogenes , Receptores Imunológicos/genética , Duplicações Segmentares Genômicas , Análise de Sequência de DNA , Família de Moléculas de Sinalização da Ativação Linfocitária , Fatores de Transcrição/metabolismoRESUMO
Polyester polyurethanes incorporating polyhedral oligosilsesquioxane (POSS) as the crystalline hard block were evaluated for biocompatibility and degradation over 24 weeks in vivo. In vitro studies were also used to predict the onset of mass loss. The molecular weight of each sample was found to decrease quickly over an 8 week period and then became constant due to the nondegrading POSS hard block. Kinetic analysis of the initial molecular weight change indicated that the degradation rate was dependent on the soft block composition. Crystallinity, melting temperature, and heat of fusion of the polyurethanes were found to increase during degradation as the amorphous polyester soft segments were hydrolyzed. The histological analysis of each polymer demonstrated rapid resolution of the acute and chronic inflammatory responses and the development of expected, normal foreign body reaction, consisting of adherent macrophages and foreign body giant cells on the surface of the polymers, and fibrous capsule formation around the polymer. No acute and/or chronic inflammation was seen after 3 weeks, indicating that the polymers in film form and biodegraded form, that is, particles, were biocompatible and did not elicit inflammatory responses expected for toxic or nonbiocompatible materials.
Assuntos
Materiais Biocompatíveis/metabolismo , Compostos de Organossilício/metabolismo , Poliésteres/metabolismo , Poliuretanos/metabolismo , Animais , Materiais Biocompatíveis/química , Reação a Corpo Estranho/patologia , Células Gigantes de Corpo Estranho/metabolismo , Células Gigantes de Corpo Estranho/patologia , Implantes Experimentais , Cinética , Teste de Materiais , Estrutura Molecular , Peso Molecular , Compostos de Organossilício/química , Poliésteres/química , Poliuretanos/química , RatosRESUMO
Sheep intelectin1 and sheep intelectin3 (sITLN1 and sITLN3) were cloned and sequenced. The amino acid sequences of sITLN1 and sITLN3 shared 86% and 91% homology with the previously cloned sheep intelectin2 (sITLN2), respectively. Expression of sITLN1 and sITLN3 transcript was demonstrated in abomasum, lung, colon and gastric lymph node, terminal rectum, skin, jejunum, mesenteric lymph node, ileal peyer's patches, brain, kidney, liver, spleen, skin, ear pinna, heart and ovary in normal sheep tissues. sITLN2 transcript expression was restricted to the abomasal mucosa in normal sheep tissues. Using a non selective chicken anti-intelectin antibody, tissue intelectin protein was demonstrated in mucus neck cells in the abomasum, mucus cells in the colon, free mucus in ileum, goblet cells in the lung, small intestinal epithelium and brush border, epidermal layer of the skin and skin sebaceous glands. The expression of the three sITLN transcripts was examined in two nematode infections in sheep known to induce a Th2 response; a Teladorsagia circumcincta challenge infection model and a Dictyocaulus filaria natural infection. The three sITLN were absent in unchallenged naïve lambs and present in the abomasal mucosa of both naïve and immune lambs following T. circumcincta challenge infection. Upregulation of sITLN2 and sITLN3 was shown in sheep lung following D. filaria natural infection. Intelectins may play an important role in the mucosal response to nematode infections in ruminants.
Assuntos
Regulação da Expressão Gênica/imunologia , Lectinas/metabolismo , Infecções por Nematoides/veterinária , Doenças dos Ovinos/metabolismo , Animais , Clonagem Molecular , Infecções por Nematoides/metabolismo , Ovinos , Doenças dos Ovinos/parasitologiaRESUMO
Highly adjustable and precisely controllable drug release from a biodegradable stent coating was achieved using a unique family of nanostructured hybrid polyurethanes. These polyurethanes are polyhedral oligosilsesquioxane thermoplastic polyurethanes (POSS TPUs) featuring alternating multiblock structures formed by nanostructured hard segments of POSS and biodegradable soft segments of a polylactide/caprolactone copolymer (P(DLLA-co-CL)) incorporating polyethylene glycol (PEG) covalently. POSS aggregated to form crystals serving as physical crosslinks on the nanometer scale, while the soft segments were designed carefully to modulate the drug release rate from the POSS TPU stent coatings in PBS buffer solution, with 90% of the drug releasing from within half a day to about 90 days. In order to interpret the underlying drug release mechanisms, an approximation model capable of describing the entire drug release process was developed. This model is based on Fickian diffusional transport, but also takes into account the polymer degradation and/or swelling of the coating, depending on the dominance of the degradation/swelling behavior compared to that of the diffusion characteristics. A general methodology was utilized for statistically fitting the drug release curves from the POSS TPU stent coatings using the model. We observed that the fitted initial drug release diffusion coefficient covered more than three orders of magnitude, depending on the polymer glass transition temperature (T(g)), according to a modified Williams-Landel-Ferry (WLF) equation. In addition, two additional rate constants describing the impact of degradation and swelling on drug elution were determined and found to be consistent with independent measurements. Our results clearly show that the studied hybrid polyurethane family allows a drug release rate that is effectively manipulated through variation in polymer T(g), degradation rate, and thickness increment rate.
Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Materiais Revestidos Biocompatíveis/química , Compostos de Organossilício/química , Paclitaxel/administração & dosagem , Poliuretanos/química , Stents , Antineoplásicos Fitogênicos/química , Materiais Revestidos Biocompatíveis/síntese química , Simulação por Computador , Difusão , Portadores de Fármacos/síntese química , Portadores de Fármacos/química , Modelos Químicos , Compostos de Organossilício/síntese química , Paclitaxel/química , Poliuretanos/síntese química , Solubilidade , Temperatura de TransiçãoRESUMO
Intelectins (Itlns) are lectins with potential roles in innate immunity, capable of binding bacteria via galactofuranose residues. Itlns also function as intestinal receptors for the antimicrobial glycoprotein lactoferrin (Lf). Since Lf binds strongly to enterohemorrhagic Escherichia coli O157:H7 (EHEC), we aimed to determine the expression of Lf receptor in terminal rectum, the site of predilection of EHEC in cattle. We sequenced two bovine intelectins (Itln1 and Itln2) and showed that both were expressed in abomasum and rectum, but expression appeared minimal in the jejunum. There was significantly higher expression of Itln2 in terminal rather than proximal rectum. Lactoferrin was expressed in all samples examined. Thus, we have demonstrated two novel bovine Itlns and shown that they are expressed along with Lf in the gastrointestinal tract, where they may interact with microbial pathogens.