Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
1.
Physiother Can ; 76(1): 78-85, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38465304

RESUMO

Purpose: Frailty is not commonly assessed on intake to cardiac rehabilitation (CR), but screening could enable targeted interventions and potentially reduce secondary complications. This study aimed to develop and retrospectively examine the feasibility of utilizing a CR-specific algorithm based on the Clinical Frailty Scale (CFS). Our CFS-CR algorithm endeavoured to screen for frailty in older adults (> 65 y) entering CR following cardiac surgery/procedure. Method: The charts of 30 former patients (mean age: 74.0 ± 6.9 y) were examined by a clinician working in CR. Results: The clinician was unable to score any of the patients based on their medical charts using the CFS-CR due to insufficient data. Documentation was typically limited in the areas of instrumental and basic activities of daily living whereas exercise data were readily available. Conclusions: Current intake documentation in CR limited the ability to retrospectively screen for frailty. This finding suggests a need for a frailty-specific tool to support routine clinical screening. Prospective evaluation of the CFS-CR is warranted to further examine the clinical utility of the algorithm during CR intake assessments.


Objectif: la fragilité est peu évaluée à l'admission en réadaptation cardiaque (RC), mais le dépistage pourrait permettre de cibler des interventions et peutêtre de réduire les complications secondaires. La présente étude visait à créer un algorithme de RC d'après l'échelle de fragilité clinique (ÉFC) et à procéder à une analyse rétrospective pour déterminer la faisabilité de l'utiliser. L'algorithme ÉFC-RC était conçu pour dépister la fragilité chez les personnes âgées (de 65 ans ou plus) qui arrivaient en RC après une opération ou une intervention cardiaque. Méthodologie: une clinicienne qui travaillait en RC a examiné les dossiers de 30 anciens patients (âge moyen de 74,0 ± 6,9 ans). Résultats: la clinicienne n'a pu mesurer les résultats d'aucun patient d'après leur dossier médical au moyen de l'ÉFC-RC en raison de données insuffisantes. Les éléments du dossier se limitaient généralement aux activités déterminantes et courantes de la vie quotidienne, tandis que les données sur les exercices étaient facilement accessibles. Conclusions: l'information contenue dans les dossiers d'admission actuels en RC limitait la possibilité de procéder à l'analyse rétrospective de la fragilité. Cette observation laisse croire à la nécessité de concevoir un outil axé sur la fragilité pour contribuer au dépistage clinique systématique. Une évaluation prospective de l'ÉFC-RC s'impose pour mieux analyser l'utilité clinique de l'algorithme lors des évaluations à l'admission en RC.

2.
Microb Biotechnol ; 16(2): 195-217, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36099200

RESUMO

Global economies depend on the use of fossil-fuel-based polymers with 360-400 million metric tons of synthetic polymers being produced per year. Unfortunately, an estimated 60% of the global production is disposed into the environment. Within this framework, microbiologists have tried to identify plastic-active enzymes over the past decade. Until now, this research has largely failed to deliver functional biocatalysts acting on the commodity polymers such as polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), ether-based polyurethane (PUR), polyamide (PA), polystyrene (PS) and synthetic rubber (SR). However, few enzymes are known to act on low-density and low-crystalline (amorphous) polyethylene terephthalate (PET) and ester-based PUR. These above-mentioned polymers represent >95% of all synthetic plastics produced. Therefore, the main challenge microbiologists are currently facing is in finding polymer-active enzymes targeting the majority of fossil-fuel-based plastics. However, identifying plastic-active enzymes either to implement them in biotechnological processes or to understand their potential role in nature is an emerging research field. The application of these enzymes is still in its infancy. Here, we summarize the current knowledge on microbial plastic-active enzymes, their global distribution and potential impact on plastic degradation in industrial processes and nature. We further outline major challenges in finding novel plastic-active enzymes, optimizing known ones by synthetic approaches and problems arising through falsely annotated and unfiltered use of database entries. Finally, we highlight potential biotechnological applications and possible re- and upcycling concepts using microorganisms.


Assuntos
Plásticos , Polímeros , Plásticos/metabolismo , Poliuretanos , Combustíveis Fósseis , Biodegradação Ambiental
3.
Sci Rep ; 11(1): 4567, 2021 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-33633281

RESUMO

Anesthetics are deemed necessary for all major surgical procedures. However, they have also been found to exert neurotoxic effects when tested on various experimental models, but the underlying mechanisms remain unknown. Earlier studies have implicated mitochondrial fragmentation as a potential target of anesthetic-induced toxicity, although clinical strategies to protect their structure and function remain sparse. Here, we sought to determine if preserving mitochondrial networks with a non-toxic, short-life synthetic peptide-P110, would protect cortical neurons against both inhalational and intravenous anesthetic-induced neurotoxicity. This study provides the first direct and comparative account of three key anesthetics (desflurane, propofol, and ketamine) when used under identical conditions, and demonstrates their impact on neonatal, rat cortical neuronal viability, neurite outgrowth and synaptic assembly. Furthermore, we discovered that inhibiting Fis1-mediated mitochondrial fission reverses anesthetic-induced aberrations in an agent-specific manner. This study underscores the importance of designing mitigation strategies invoking mitochondria-mediated protection from anesthetic-induced toxicity in both animals and humans.


Assuntos
Anestésicos Gerais/efeitos adversos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fármacos Neuroprotetores/farmacologia , Peptídeos/farmacologia , Sinapses/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Células Cultivadas , Imunofluorescência , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Fármacos Neuroprotetores/síntese química , Peptídeos/síntese química , Propofol/efeitos adversos , Ratos , Espécies Reativas de Oxigênio/metabolismo , Superóxidos/metabolismo
4.
Appl Environ Microbiol ; 85(19)2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31324632

RESUMO

Plastics are widely used in the global economy, and each year, at least 350 to 400 million tons are being produced. Due to poor recycling and low circular use, millions of tons accumulate annually in terrestrial or marine environments. Today it has become clear that plastic causes adverse effects in all ecosystems and that microplastics are of particular concern to our health. Therefore, recent microbial research has addressed the question of if and to what extent microorganisms can degrade plastics in the environment. This review summarizes current knowledge on microbial plastic degradation. Enzymes available act mainly on the high-molecular-weight polymers of polyethylene terephthalate (PET) and ester-based polyurethane (PUR). Unfortunately, the best PUR- and PET-active enzymes and microorganisms known still have moderate turnover rates. While many reports describing microbial communities degrading chemical additives have been published, no enzymes acting on the high-molecular-weight polymers polystyrene, polyamide, polyvinylchloride, polypropylene, ether-based polyurethane, and polyethylene are known. Together, these polymers comprise more than 80% of annual plastic production. Thus, further research is needed to significantly increase the diversity of enzymes and microorganisms acting on these polymers. This can be achieved by tapping into the global metagenomes of noncultivated microorganisms and dark matter proteins. Only then can novel biocatalysts and organisms be delivered that allow rapid degradation, recycling, or value-added use of the vast majority of most human-made polymers.


Assuntos
Biodegradação Ambiental , Biotecnologia , Ecossistema , Microbiota , Plásticos/metabolismo , Monitoramento Ambiental , Enzimas , Metagenoma , Reciclagem
5.
Surg Infect (Larchmt) ; 20(5): 416-423, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30912706

RESUMO

Background: Reactivation of latent cytomegalovirus (CMV) infection occurs in previously immunocompetent critically ill individuals and may be associated with increased morbidity and mortality. Our aim was to explore risk factors for and outcomes after CMV reactivation in patients undergoing major surgery. Patients and Methods: We performed a retrospective case control study of patients without underlying immunocompromise who developed post-operative CMV reactivation from 2004-2016. Cases included patients testing positive for CMV by viral load, culture, or histopathology. Controls were matched by age, gender, type, and year of surgery. Results: Sixteen CMV cases were matched to 32 controls. Median age was 65 and median time from surgery to CMV diagnosis was 32 days. Symptoms included fever (94%), hepatitis (75%), myelosuppression (56%), and diarrhea (38%). Despite similar baseline comorbidities, cases were more likely to return to surgery (odds ratio [OR] 6.31; 95% confidence interval [CI], 1.29-30.74), require renal replacement therapy (OR 18.54; 95% CI, 2.36-145.6), total parenteral nutrition (OR 33.0; 95% CI, 6.60-262.37) and corticosteroids (OR 18.78; 95% CI, 4.5-103.9). Length of stay was increased (median 51 vs. 8 days, p = 0.005), co-infections were more common (OR 15.10; 95% CI, 1.89-120.8), and mortality was higher (38% vs. 0%, p < 0.01). Conclusions: Cytomegalovirus reactivation occurs in previously immunocomptent patients post-operatively and is associated with poor outcomes including other infections and mortality. Potential risk factors include prolonged length of stay, surgical complications, and corticosteroid use. It is not clear from our study whether CMV reactivation is a surrogate marker of severe illness and post-operative complications or if CMV reactivation plays a causative role in the development of these adverse outcomes.


Assuntos
Infecções por Citomegalovirus/epidemiologia , Citomegalovirus/crescimento & desenvolvimento , Período Pós-Operatório , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Ativação Viral , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento , Carga Viral
6.
Prenat Diagn ; 38(13): 1069-1078, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30357877

RESUMO

OBJECTIVE: To gather additional data on the ability to detect subchromosomal abnormalities of various sizes in single fetal cells isolated from maternal blood, using low-coverage shotgun next-generation sequencing for cell-based noninvasive prenatal testing (NIPT). METHOD: Fetal trophoblasts were recovered from approximately 30 mL of maternal blood using maternal white blood cell depletion, density-based cell separation, immunofluorescence staining, and high-resolution scanning. These trophoblastic cells were picked as single cells and underwent whole genome amplification for subsequent genome-wide copy number analysis and genotyping to confirm the fetal origin of the cells. RESULTS: Applying our fetal cell isolation method to a series of 125 maternal blood samples, we detected on average 4.17 putative fetal cells/sample. The series included 15 cases with clinically diagnosed fetal aneuploidies and five cases with subchromosomal abnormalities. This method was capable of detecting findings that were 1 to 2 Mb in size, and all were concordant with the microarray or karyotype data obtained on a fetal sample. A minority of fetal cells showed evidence of genome degradation likely related to apoptosis. CONCLUSION: We demonstrate that this cell-based NIPT method has the capacity to reliably diagnose fetal chromosomal abnormalities down to 1 to 2 Mb in size.


Assuntos
Aberrações Cromossômicas , Variações do Número de Cópias de DNA , Deleção de Genes , Duplicação Gênica , Trofoblastos/metabolismo , Adulto , Separação Celular , Deleção Cromossômica , Feminino , Imunofluorescência , Genótipo , Humanos , Cariótipo , Masculino , Gravidez , Diagnóstico Pré-Natal , Análise de Célula Única , Análise Serial de Tecidos , Adulto Jovem
7.
Methods Mol Biol ; 1634: 181-192, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28819851

RESUMO

The CytePicker module built into the RareCyte CyteFinder instrument allows researchers to easily retrieve individual cells from microscope slides for genomic analyses, including array CGH, targeted sequencing, and next-generation sequencing. Here, we describe the semiautomated retrieval of CTCs from the blood processed by AccuCyte (see Chapter 13) and amplification of genomic DNA so that molecular analysis can be performed.


Assuntos
Separação Celular/métodos , Células Imobilizadas/patologia , Neoplasias/diagnóstico , Células Neoplásicas Circulantes/patologia , Técnicas de Amplificação de Ácido Nucleico/métodos , Análise de Célula Única/métodos , Automação Laboratorial/instrumentação , Contagem de Células , Linhagem Celular Tumoral , Separação Celular/instrumentação , Células Imobilizadas/imunologia , Células Imobilizadas/metabolismo , Centrifugação/instrumentação , Centrifugação/métodos , Hibridização Genômica Comparativa , Desenho de Equipamento , Genoma Humano , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Neoplasias/sangue , Neoplasias/imunologia , Neoplasias/patologia , Células Neoplásicas Circulantes/imunologia , Células Neoplásicas Circulantes/metabolismo , Análise de Célula Única/instrumentação
8.
Liver Transpl ; 23(12): 1541-1552, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28703464

RESUMO

Though serum iron has been known to be associated with an increased risk of infection, hepcidin, the major regulator of iron metabolism, has never been systematically explored in this setting. Finding early biomarkers of infection, such as hepcidin, could help identify patients in whom early empiric antimicrobial therapy would be beneficial. We prospectively enrolled consecutive patients (n = 128) undergoing first-time, single-organ orthotopic liver transplantation (OLT) without known iron overload disorders at 2 academic hospitals in Boston from August 2009 to November 2012. Cox regression compared the associations between different iron markers and the development of first infection at least 1 week after OLT; 47 (37%) patients developed a primary outcome of infection at least 1 week after OLT and 1 patient died. After adjusting for perioperative bleeding complications, number of hospital days, and hepatic artery thrombosis, changes in iron markers were associated with the development of infection post-OLT including increasing ferritin (hazard ratio [HR], 1.51; 95% confidence interval [CI], 1.12-2.05), rising ferritin slope (HR, 1.10; 95% CI, 1.03-1.17), and increasing hepcidin (HR, 1.43; 95% CI, 1.05-1.93). A decreasing iron (HR, 1.76; 95% CI, 1.20-2.57) and a decreasing iron slope (HR, 4.21; 95% CI, 2.51-7.06) were also associated with subsequent infections. In conclusion, hepcidin and other serum iron markers and their slope patterns or their combination are associated with infection in vulnerable patient populations. Liver Transplantation 23 1541-1552 2017 AASLD.


Assuntos
Doenças Transmissíveis/sangue , Doença Hepática Terminal/cirurgia , Ferro/sangue , Transplante de Fígado/efeitos adversos , Complicações Pós-Operatórias/sangue , Biomarcadores/sangue , Boston/epidemiologia , Doenças Transmissíveis/epidemiologia , Doenças Transmissíveis/imunologia , Doenças Transmissíveis/microbiologia , Feminino , Ferritinas/sangue , Hepcidinas/sangue , Interações Hospedeiro-Patógeno/imunologia , Humanos , Hospedeiro Imunocomprometido , Ferro/metabolismo , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/imunologia , Complicações Pós-Operatórias/microbiologia , Estudos Prospectivos , Reoperação/estatística & dados numéricos , Medição de Risco/métodos , Resultado do Tratamento
9.
Ann Thorac Surg ; 100(3): 1109-11, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26354646

RESUMO

Tracheobronchial fibromas are very rare, locally-invasive tumors of the airways. Fewer than 30 cases have been reported within the English-speaking literature. Historically, these neoplasms have been diagnosed as isolated endobronchial masses, with affected patients presenting with wheezing, cough, stridor, hemoptysis, dyspnea, or pneumonia. We report the case of 39-year-old man with multiple, synchronous endobronchial fibromas causing unilobar emphysema. A computed tomographic scan and bronchoscopy with biopsy were performed preoperatively to diagnose these lesions in the orifices of the anterior segment and the lingula within the left upper lobe. The patient underwent successful video-assisted left upper lobectomy, without recurrence at 3 years. This is the first report of a synchronous presentation of multiple pulmonary endobronchial fibromas within the same patient and the first report of endobronchial fibroma presenting as unilobar air trapping. Recognition of the unusual presentation of this uncommon pathology can lead to timely intervention.


Assuntos
Neoplasias Brônquicas/complicações , Fibroma/complicações , Enfisema Pulmonar/etiologia , Adulto , Neoplasias Brônquicas/diagnóstico , Fibroma/diagnóstico , Humanos , Masculino
11.
J Biol Chem ; 290(16): 10018-36, 2015 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-25635057

RESUMO

A major goal of current signaling research is to develop a quantitative understanding of how receptor activation is coupled to downstream signaling events and to functional cellular responses. Here, we measure how activation of the RET receptor tyrosine kinase on mouse neuroblastoma cells by the neurotrophin artemin (ART) is quantitatively coupled to key downstream effectors. We show that the efficiency of RET coupling to ERK and Akt depends strongly on ART concentration, and it is highest at the low (∼100 pM) ART levels required for neurite outgrowth. Quantitative discrimination between ERK and Akt pathway signaling similarly is highest at this low ART concentration. Stimulation of the cells with 100 pM ART activated RET at the rate of ∼10 molecules/cell/min, leading at 5-10 min to a transient peak of ∼150 phospho-ERK (pERK) molecules and ∼50 pAkt molecules per pRET, after which time the levels of these two signaling effectors fell by 25-50% while the pRET levels continued to slowly rise. Kinetic experiments showed that signaling effectors in different pathways respond to RET activation with different lag times, such that the balance of signal flux among the different pathways evolves over time. Our results illustrate that measurements using high, super-physiological growth factor levels can be misleading about quantitative features of receptor signaling. We propose a quantitative model describing how receptor-effector coupling efficiency links signal amplification to signal sensitization between receptor and effector, thereby providing insight into design principles underlying how receptors and their associated signaling machinery decode an extracellular signal to trigger a functional cellular outcome.


Assuntos
Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Fosfoproteínas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-ret/metabolismo , Animais , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica , Cinética , Ligantes , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteínas do Tecido Nervoso/farmacologia , Neurônios/citologia , Neurônios/efeitos dos fármacos , Fosfoproteínas/genética , Fosforilação , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-ret/genética , Transdução de Sinais , Fatores de Tempo
12.
Circulation ; 130(14): 1179-91, 2014 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-25062690

RESUMO

BACKGROUND: Pulmonary veno-occlusive disease is caused by excessive cell proliferation and fibrosis, which obliterate the lumen of pulmonary venules, leading to pulmonary hypertension, right ventricular failure, and death. This condition has no effective treatment and a 5-year survival of <5%. Understanding the mechanism of this disease and designing effective therapies are urgently needed. METHODS AND RESULTS: We show that mice with homozygous deletion of the Ets transcription factor Erg die between embryonic day 16.5 and 3 months of age as a result of pulmonary veno-occlusive disease, capillary hemorrhage, and pancytopenia. We demonstrate that Erg binds to and serves as a transcriptional activator of the G-protein-coupled receptor gene Aplnr, the expression of which is uniquely specific for venous endothelium and that knockout of either Erg or Aplnr results in pulmonary venule-specific endothelial proliferation in vitro. We show that mice with either homozygous-global or endothelium-directed deletion of Aplnr manifest pulmonary veno-occlusive disease and right heart failure, detectable at 8 months of age. Levels of pulmonary ERG and APLNR in patients with pulmonary veno-occlusive disease undergoing lung transplantation were significantly lower than those of control subjects. CONCLUSIONS: Our results suggest that ERG and APLNR are essential for endothelial homeostasis in venules in the lung and that perturbation in ERG-APLNR signaling is crucial for the development of pulmonary veno-occlusive disease. We identify this pathway as a potential therapeutic target for the treatment of this incurable disease.


Assuntos
Proteínas Oncogênicas/genética , Pneumopatia Veno-Oclusiva/patologia , Receptores Acoplados a Proteínas G/genética , Transativadores/genética , Fatores de Transcrição/genética , Animais , Receptores de Apelina , Proliferação de Células , Células Cultivadas , Células Endoteliais/patologia , Feminino , Expressão Gênica/fisiologia , Humanos , Óperon Lac , Transplante de Pulmão , Masculino , Camundongos , Camundongos Knockout , Proteínas Oncogênicas/metabolismo , Fenótipo , Regiões Promotoras Genéticas/fisiologia , Artéria Pulmonar/patologia , Veias Pulmonares/patologia , Pneumopatia Veno-Oclusiva/cirurgia , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais/fisiologia , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , Regulador Transcricional ERG
13.
Nat Med ; 16(12): 1450-5, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21102459

RESUMO

Refined cancer models are required if researchers are to assess the burgeoning number of potential targets for cancer therapeutics in a clinically relevant context that allows a fast turnaround. Here we use tumor-associated genetic pathways to transform primary human epithelial cells from the epidermis, oropharynx, esophagus and cervix into genetically defined tumors in a human three-dimensional (3D) tissue environment that incorporates cell-populated stroma and intact basement membrane. These engineered organotypic tissues recapitulated natural features of tumor progression, including epithelial invasion through basement membrane, a complex process that is necessary for biological malignancy in 90% of human cancers. Invasion was rapid and was potentiated by stromal cells. Oncogenic signals in 3D tissue, but not 2D culture, resembled gene expression profiles from spontaneous human cancers. We screened 3D organotypic neoplasia with well-characterized signaling pathway inhibitors to distill a clinically faithful cancer gene signature. Multitissue 3D human tissue cancer models may provide an efficient and relevant complement to current approaches to characterizing cancer progression.


Assuntos
Transformação Celular Neoplásica/genética , Células Epiteliais/citologia , Modelos Biológicos , Invasividade Neoplásica/fisiopatologia , Neoplasias/genética , Engenharia Tecidual/métodos , Membrana Basal/citologia , Butadienos , Cromonas , Perfilação da Expressão Gênica , Humanos , Morfolinas , Nitrilas , Células Estromais/citologia
14.
Clin Infect Dis ; 51(3): e16-23, 2010 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-20578876

RESUMO

BACKGROUND: Elevated serum iron levels have been associated with infectious outcomes in various patient populations but, to our knowledge, have never been studied after liver transplantation. METHODS: The relationship between serum iron levels and infectious outcomes after liver transplantation was evaluated in a nested case-control study using prospectively collected data and serum samples. Unadjusted and adjusted hazard ratios were calculated for each iron marker predictor variable (iron level, unsaturated iron-binding capacity, total iron-binding capacity, transferrin saturation, and ferritin level) and time to development of each of 6 outcomes (cytomegalovirus [CMV] disease, invasive fungal infection, bacteremia, invasive fungal infection or bacteremia, any infection, and 1-year mortality rate). RESULTS: Serum measurements (n = 109) corresponding to increased levels of serum iron were independently associated with an increased risk of any infection and death. After adjusting for the number of red blood cell transfusions, donor CMV-seropositive status, and fungal colonization, ferritin level was independently associated with the development of any infection (hazard ratio, 1.09; 95% confidence interval, 1.04-1.14). After adjusting for the number of red blood cell transfusions, development of CMV disease, and administration of intravenous steroids for treatment of rejection, ferritin level was also was independently associated with death (hazard ratio, 1.11; 95% confidence interval, 1.04-1.18). Similar results were found for unsaturated iron binding capacity for the same 2 outcomes. CONCLUSIONS: A better understanding of iron metabolism and its relationship to infection could help guide future infection prognosis, prevention, and management efforts in this high-risk population.


Assuntos
Doenças Transmissíveis/epidemiologia , Ferro/sangue , Transplante de Fígado/efeitos adversos , Soro/química , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Medição de Risco , Adulto Jovem
15.
J Appl Clin Med Phys ; 9(1): 36-46, 2008 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-18449163

RESUMO

In order to analyze the magnitude of set up errors corrected by Helical TomoTherapy Mega-Voltage CT on a daily or weekly basis and their impact on the delivered dose to the tumor and organs at risk (OAR), the setup errors of 6 nasal cavity and 4 nasopharyngeal cancer patients who were treated with Helical Tomotherapy for 25-33 fractions were retrospectively analyzed. Each patient had MVCT guided repositioning for all fractions of treatment. The new dose volume histogram (DVH) and equivalent uniform dose (EUD) for planning target volume (PTV) and OARs were calculated for hypothetical situations where no imaging guidance (IG) or once weekly image guidance (WIG) took place. The mean total set up error if treated without daily IG was 3.6+/-1.0 mm, which can be reduced to 1.7+/-0.6 mm if a WIG was performed. The geometrical uncertainties from the absence of image guidance resulted in a reduction of mean PTV EUD dose by 2.1+/-1.0 %, which can be reduced to 1.4+/-1.0 % with WIG. The EUD of OARs increased 1.8+/-2.0 Gy or 0.8+/-1.3 Gy without or with WIG respectively. Without daily IG, the mean patient position uncertainty has relatively small impacts on the mean PTV and OAR dosimetry, which can be further reduced approximately by half using a WIG. On the other hand, because of the large variance, with low probability, substantial deviation from the original planned dosimetry may occur without IG. Therefore, daily MVCT is preferred as an important safety measure in the IMRT.


Assuntos
Neoplasias Nasofaríngeas/diagnóstico por imagem , Neoplasias Nasofaríngeas/radioterapia , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Radiometria/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/métodos , Tomografia Computadorizada Espiral/métodos , Humanos , Cavidade Nasal/diagnóstico por imagem , Dosagem Radioterapêutica , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
16.
Proc Natl Acad Sci U S A ; 104(24): 10104-9, 2007 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-17537922

RESUMO

During embryogenesis, the XIST RNA is expressed from and localizes to one X chromosome in females and induces chromosome-wide silencing. Although many changes to inactive X heterochromatin are known, the functional relationships between different modifications are not well understood, and studies of the initiation of X-inactivation have been largely confined to mouse. We now present a model system for human XIST RNA function in which induction of an XIST cDNA in somatic cells results in localized XIST RNA and transcriptional silencing. Chromatin immunoprecipitation and immunohistochemistry shows that this silencing need only be accompanied by a subset of heterochromatic marks and that these can differ between integration sites. Surprisingly, silencing is XIST-dependent, remaining reversible over extended periods. Deletion analysis demonstrates that the first exon of human XIST is sufficient for both transcript localization and the induction of silencing and that, unlike the situation in mice, the conserved repeat region is essential for both functions. In addition to providing mechanistic insights into chromosome regulation and formation of facultative heterochromatin, this work provides a tractable model system for the study of chromosome silencing and suggests key differences from mouse embryonic X-inactivation.


Assuntos
Cromossomos Humanos X/genética , Mecanismo Genético de Compensação de Dose , RNA não Traduzido , Inativação do Cromossomo X , Imunoprecipitação da Cromatina , Cromossomos Humanos X/metabolismo , Metilação de DNA , DNA Complementar , Doxiciclina/farmacologia , Fibrossarcoma/patologia , Inativação Gênica , Heterocromatina , Histonas/química , Histonas/metabolismo , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Modelos Genéticos , RNA Longo não Codificante , Análise de Sequência de DNA
17.
Bioorg Med Chem Lett ; 17(14): 4026-9, 2007 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-17502145

RESUMO

Herein, we pursue the hypothesis that the structure of nordihydroguaiaretic acid (NDGA) can be refined for selective potency against the insulin-like growth factor 1 receptor (IGF-1R) as a potential therapeutic target for breast cancer while diminishing its action against other cellular targets. Thus, a set of NDGA analogs (7a-7h) was prepared and examined for inhibitory potency against IGF-1R kinase and an alternative target, 15-lipoxygenase (15 LOX). The anti-cancer effects of these compounds were determined by their ability to inhibit IGF-1 mediated cell growth of MCF-7 breast cancer cells. The design of the analogs was based upon a cursory Topliss approach in which one of NDGA's aromatic rings was modified with various substituents. Structural modification of one of the two catechol rings of NDGA was found to have little effect upon the inhibitory potency against both kinase activity of the IGF-1R and IGF-1 mediated cell growth of MCF-7 cells. 15-LOX was found to be most sensitive to structural modifications of NDGA. From the limited series of NDGA analogs examined, the compound that exhibited the greatest selectivity for IGF-1 mediated growth compared to 15-LOX inhibition was a cyclic analog 7h with a framework similar to a natural product isolated from Larrea divaricata. The results for 7h are significant because while NDGA displays biological promiscuity, 7h exhibits greater specificity toward the breast cancer target IGF-1R with that added benefit of possessing a 10-fold weaker potency against 15-LOX, an enzyme which has a purported tumor suppressing role in breast cancer. With increased specificity and potency, 7h may serve as a new lead in developing novel therapeutic agents for breast cancer.


Assuntos
Inibidores de Lipoxigenase/farmacologia , Masoprocol/farmacologia , Receptor IGF Tipo 1/antagonistas & inibidores , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Humanos , Masoprocol/análogos & derivados
18.
Genomics ; 82(3): 309-22, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12906856

RESUMO

X inactivation requires XIST, a functional RNA that is expressed exclusively from, and localizes to, the inactive X in female somatic cells. In mouse, low-level unstable transcription of Xist is observed prior to the time of inactivation, and an antisense transcript, Tsix, is a critical regulator of early Xist expression. To examine the presence and impact of an antisense transcript in humans we have characterized the extent of sense and antisense transcription in human somatic, transgenic, and embryonal carcinoma (EC) cell lines. Downstream antisense expression at the human XIST locus was not detected in somatic cells, but was detected in the EC line N-Tera2D1 and in somatic cells with an ectopic XIST locus. Presence of the antisense did not disrupt the stability or localization of the sense transcript. We have also identified additional sense transcripts in EC and female somatic cells and demonstrate that the 5' flanking JPX/ENOX gene is expressed from both the active and the inactive X chromosome in somatic cell hybrids, delimiting the extent of inactive X-specific transcriptional control in somatic cells. These analyses reveal similarities to and differences from the murine Xist and Tsix transcripts and generate a complex picture of developmentally regulated transcription through the region.


Assuntos
Antibacterianos/farmacologia , Carcinoma Embrionário/metabolismo , Dactinomicina/farmacologia , Expressão Gênica/efeitos dos fármacos , RNA não Traduzido/genética , Animais , Bovinos , Feminino , Humanos , Masculino , Camundongos , RNA Longo não Codificante , RNA não Traduzido/biossíntese , RNA não Traduzido/efeitos dos fármacos , Transgenes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA