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1.
AJNR Am J Neuroradiol ; 43(11): 1603-1607, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36265891

RESUMO

BACKGROUND AND PURPOSE: The presence of malformations of cortical development in patients with hereditary hemorrhagic telangiectasia has been reported on previous occasions. We evaluated a sample of adults with hereditary hemorrhagic telangiectasia for the presence of malformations of cortical development, spatial coincidence of malformations of cortical development and AVMs, and the coincidence of brain and pulmonary AVMs. MATERIALS AND METHODS: A total of 141 patients 18 years of age or older who were referred to the Augusta University hereditary hemorrhagic telangiectasia clinic and underwent brain MR imaging between January 19, 2018, and December 3, 2020, were identified. MR imaging examinations were reviewed retrospectively by 2 experienced neuroradiologists, and the presence of malformations of cortical development and AVMs was confirmed by consensus. Demographic and clinical information was collected for each case, including age, sex, hereditary hemorrhagic telangiectasia status by the Curacao Criteria, mutation type, presence of malformations of cortical development, presence of brain AVMs, presence of pulmonary AVMs, and a history of seizures or learning disabilities. RESULTS: Five of 141 (3.5%) patients with hereditary hemorrhagic telangiectasia had malformations of cortical development. Two of the 5 patients with polymicrogyria also had closed-lip schizencephaly. One of the patients had a porencephalic cavity partially lined with heterotopic GM. The incidence of spatially coincident polymicrogyria and brain AVMs was 40% (2/5 cases). Of the patients with hereditary hemorrhagic telangiectasia and malformations of cortical development, 4/5 (80%) had pulmonary AVMs and 2/5 (40%) had brain AVMs. CONCLUSIONS: To our knowledge, we are the first group to report the presence of schizencephaly in patients with hereditary hemorrhagic telangiectasia. The presence of schizencephaly and porencephaly lends support to the hypothesis of regional in utero cerebral hypoxic events as the etiology of malformations of cortical development in hereditary hemorrhagic telangiectasia.


Assuntos
Malformações Arteriovenosas , Polimicrogiria , Esquizencefalia , Telangiectasia Hemorrágica Hereditária , Adulto , Humanos , Adolescente , Telangiectasia Hemorrágica Hereditária/complicações , Telangiectasia Hemorrágica Hereditária/diagnóstico por imagem , Telangiectasia Hemorrágica Hereditária/epidemiologia , Estudos Retrospectivos
2.
Artigo em Inglês | MEDLINE | ID: mdl-32477621

RESUMO

Endometriosis is a complex and high impact disease affecting 176 million women worldwide with diagnostic latency between 4 to 11 years due to lack of a definitive clinical symptom or a minimally invasive diagnostic method. In this study, we developed a new ensemble machine learning classifier based on chromosomal partitioning, named GenomeForest and applied it in classifying the endometriosis vs. the control patients using 38 RNA-seq and 80 enrichment-based DNA-methylation (MBD-seq) datasets, and computed performance assessment with six different experiments. The ensemble machine learning models provided an avenue for identifying several candidate biomarker genes with a very high F1 score; a near perfect F1 score (0.968) for the transcriptomics dataset and a very high F1 score (0.918) for the methylomics dataset. We hope in the future a less invasive biopsy can be used to diagnose endometriosis using the findings from such ensemble machine learning classifiers, as demonstrated in this study.

3.
Mucosal Immunol ; 11(3): 894-908, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29091081

RESUMO

Airborne pathogens commonly trigger severe respiratory failure or death in smokers with lung disease. Cigarette smoking compromises the effectiveness of innate immunity against infections but the underlying mechanisms responsible for defective acquired immune responses in smokers remains less clear. We found that mice exposed to chronic cigarette smoke recovered poorly from primary Influenza A pneumonia with reduced type I and II interferons (IFNs) and viral-specific immunoglobulins, but recruited γδ T cells to the lungs that predominantly expressed interleukin 17A (IL-17A). Il-17a-/- mice exposed to smoke and infected with Influenza A also recruited γδ T cells to the lungs, but in contrast to wild-type mice, expressed increased IFNs, made protective influenza-specific antibodies, and recovered from infection. Depletion of IL-17A with blocking antibodies significantly increased T-bet expression in γδ T cells and improved recovery from acute Influenza A infection in air, but not smoke-exposed mice. In contrast, when exposed to smoke, γδ T cell deficient mice failed to mount an effective immune response to Influenza A and showed increased mortality. Our findings demonstrate a protective role for γδ T cells in smokers and suggest that smoke-induced increase in IL-17A inhibits the transcriptional programs required for their optimal anti-viral responses. Cigarette smoke induces IL-17A expression in the lungs and inhibits γδ T-cell-mediated protective anti-viral immune responses.


Assuntos
Vírus da Influenza A/imunologia , Pulmão/patologia , Infecções por Orthomyxoviridae/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Linfócitos T/fisiologia , Animais , Anticorpos Antivirais/sangue , Fumar Cigarros/efeitos adversos , Progressão da Doença , Feminino , Genes Codificadores da Cadeia delta de Receptores de Linfócitos T , Imunidade Celular , Imunidade Inata , Interleucina-17/genética , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores de Antígenos de Linfócitos T gama-delta/genética
4.
Astrobiology ; 17(11): 1123-1137, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29039682

RESUMO

In 2020, the ESA ExoMars and NASA Mars 2020 missions will be launched to Mars to search for evidence of past and present life. In preparation for these missions, terrestrial analog samples of rock formations on Mars are studied in detail in order to optimize the scientific information that the analytical instrumentation will return. Desert varnishes are thin mineral coatings found on rocks in arid and semi-arid environments on Earth that are recognized as analog samples. During the formation of desert varnishes (which takes many hundreds of years), organic matter is incorporated, and microorganisms may also play an active role in the formation process. During this study, four complementary analytical techniques proposed for Mars missions (X-ray diffraction [XRD], Raman spectroscopy, elemental analysis, and pyrolysis-gas chromatography-mass spectrometry [Py-GC-MS]) were used to interrogate samples of desert varnish and describe their capacity to sustain life under extreme scenarios. For the first time, both the geochemistry and the organic compounds associated with desert varnish are described with the use of identical sets of samples. XRD and Raman spectroscopy measurements were used to nondestructively interrogate the mineralogy of the samples. In addition, the use of Raman spectroscopy instruments enabled the detection of ß-carotene, a highly Raman-active biomarker. The content and the nature of the organic material in the samples were further investigated with elemental analysis and methylated Py-GC-MS, and a bacterial origin was determined to be likely. In the context of planetary exploration, we describe the habitable nature of desert varnish based on the biogeochemical composition of the samples. Possible interference of the geological substrate on the detectability of pyrolysis products is also suggested. Key Words: Desert varnish-Habitability-Raman spectroscopy-Py-GC-MS-XRD-ExoMars-Planetary science. Astrobiology 17, 1123-1137.


Assuntos
Clima Desértico , Exobiologia/métodos , Marte , Minerais/análise , Pintura/análise , Planeta Terra , Exobiologia/instrumentação , Cromatografia Gasosa-Espectrometria de Massas/instrumentação , Cromatografia Gasosa-Espectrometria de Massas/métodos , Minerais/química , Voo Espacial , Análise Espectral Raman/instrumentação , Análise Espectral Raman/métodos , Difração de Raios X/instrumentação , Difração de Raios X/métodos
5.
Cell Death Discov ; 2: 16061, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27625792

RESUMO

We have previously observed the reversal of lipid droplet deposition in skeletal muscle of morbidly obese patients following bariatric surgery. We now investigated whether activation of autophagy is the mechanism underlying this observation. For this purpose, we incubated rat L6 myocytes over a period of 6 days with long-chain fatty acids (an equimolar, 1.0 mM, mixture of oleate and palmitate in the incubation medium). At day 6, the autophagic inhibitor (bafilomycin A1, 200 nM) and the autophagic activator (rapamycin, 1 µM) were added separately or in combination for 48 h. Intracellular triglyceride (TG) accumulation was visualized and quantified colorimetrically. Protein markers of autophagic flux (LC3 and p62) and cell death (caspase-3 cleavage) were measured by immunoblotting. Inhibition of autophagy by bafilomycin increased TG accumulation and also increased lipid-mediated cell death. Conversely, activation of autophagy by rapamycin reduced both intracellular lipid accumulation and cell death. Unexpectedly, treatment with both drugs added simultaneously resulted in decreased lipid accumulation. In this treatment group, immunoblotting revealed p62 degradation (autophagic flux), immunofluorescence revealed the colocalization of p62 with lipid droplets, and co-immunoprecipitation confirmed the interaction of p62 with ADRP (adipose differentiation-related protein), a lipid droplet membrane protein. Thus the association of p62 with lipid droplet turnover suggests a novel pathway for the breakdown of lipid droplets in muscle cells. In addition, treatment with rapamycin and bafilomycin together also suggested the export of TG into the extracellular space. We conclude that lipophagy promotes the clearance of lipids from myocytes and switches to an alternative, p62-mediated, lysosomal-independent pathway in the context of chronic lipid overload (*P<0.05, **P<0.01, ***P<0.001, ****P<0.0001).

7.
J Pain Palliat Care Pharmacother ; 28(4): 382-3, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25338104

RESUMO

Palliative sedation is defined as the use of sedative drugs in order to reduce the patient's consciousness in case of refractory symptoms. The most used drug is midazolam, a benzodiazepine with a short half-life administered either intravenously or subcutaneously. We discuss on a clinical case requiring an exceptionally high dosage of midazolam-up to 160 mg iv daily-to achieve palliative sedation. The patient was an HIV positive 29-year-old male who was suffering from progressive multifocal leukoencephalopathy complicated by a refractory status epilepticus and who was suspected of previous benzodiazepines and opioid abuse. In such situations of a suffering brain doses of midazolam to achieve symptom control may be much higher than expected.


Assuntos
Hipnóticos e Sedativos/uso terapêutico , Leucoencefalopatia Multifocal Progressiva/complicações , Midazolam/uso terapêutico , Estado Epiléptico/complicações , Estado Epiléptico/tratamento farmacológico , Adulto , Humanos , Leucoencefalopatia Multifocal Progressiva/tratamento farmacológico , Masculino , Cuidados Paliativos/métodos
8.
J Thorac Oncol ; 9(9): 1255-63, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25122422

RESUMO

INTRODUCTION: Fluorescence in situ hybridization (FISH) is currently the standard for diagnosing anaplastic lymphoma kinase (ALK)-rearranged (ALK+) lung cancers for ALK inhibitor therapies. ALK immunohistochemistry (IHC) may serve as a screening and alternative diagnostic method. The Canadian ALK (CALK) study was initiated to implement a multicenter optimization and standardization of laboratory developed ALK IHC and FISH tests across 14 hospitals. METHODS: Twenty-eight lung adenocarcinomas with known ALK status were used as blinded study samples. Thirteen laboratories performed IHC using locally developed staining protocols for 5A4, ALK1, or D5F3 antibodies; results were assessed by H-score. Twelve centers conducted FISH using protocols based on Vysis' ALK break-apart FISH kit. Initial IHC results were used to optimize local IHC protocols, followed by a repeat IHC study to assess the results of standardization. Three laboratories conducted a prospective parallel IHC and FISH analysis on 411 consecutive clinical samples using post-validation optimized assays. RESULTS: Among study samples, FISH demonstrated 22 consensus ALK+ and six ALK wild type tumors. Preoptimization IHC scores from 12 centers with 5A4 and the percent abnormal cells by FISH from 12 centers showed intraclass correlation coefficients of 0.83 and 0.68, respectively. IHC optimization improved the intraclass correlation coefficients to 0.94. Factors affecting FISH scoring and outliers were identified. Post-optimization concurrent IHC/FISH testing in 373 informative cases revealed 100% sensitivity and specificity for IHC versus FISH. CONCLUSIONS: Multicenter standardization study may accelerate the implementation of ALK testing protocols across a country/region. Our data support the use of an appropriately validated IHC assay to screen for ALK+ lung cancers.


Assuntos
Adenocarcinoma/enzimologia , Neoplasias Pulmonares/enzimologia , Receptores Proteína Tirosina Quinases/metabolismo , Adenocarcinoma/diagnóstico , Adenocarcinoma/genética , Adenocarcinoma de Pulmão , Quinase do Linfoma Anaplásico , Canadá , DNA de Neoplasias/genética , Feminino , Seguimentos , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente/métodos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Receptores Proteína Tirosina Quinases/genética , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa
9.
Drugs Aging ; 31(6): 405-11, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24817569

RESUMO

The prevalence of pain is high in the elderly and increases with the occurrence of cancer. Pain treatment is challenging because of age-related factors such as co-morbidities, and over half of the patients with cancer pain experience transient exacerbation of pain that is known as breakthrough pain (BTP). As with background pain, BTP should be properly assessed before being treated. The first step to be taken is optimizing around-the-clock analgesia with expert titration of the painkiller. Rescue medication should then be provided as per the requested need, while at the same time preventing identified potential precipitating factors. In the elderly, starting treatment with a lower dose of analgesics may be justified because of age-related physiological changes such as decreased hepatic and renal function. Whenever possible, oral medication should be provided prior to a painful maneuver. In the case of unpredictable BTP, immediate rescue medication is mandatory and the subcutaneous route is preferred unless patient-controlled analgesia via continuous drug infusion is available. Recently, transmucosal preparations have appeared in the medical armamentarium but it is not yet known whether they represent a truly efficient alternative, although their rapid onset of activity is already well recognized. Adjuvant analgesics, topical analgesics, anesthetic techniques and interventional techniques are all valid methods to help in the difficult management of pain and BTP in elderly patients with cancer. However, none has reached a satisfying scientific level of evidence as to nowadays make the development of undisputed best practice guidelines possible. Further research is therefore on the agenda.


Assuntos
Dor Irruptiva/tratamento farmacológico , Neoplasias/tratamento farmacológico , Manejo da Dor/métodos , Cuidados Paliativos/métodos , Idoso , Idoso de 80 Anos ou mais , Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/efeitos adversos , Analgésicos Opioides/uso terapêutico , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/efeitos adversos , Anti-Inflamatórios não Esteroides/uso terapêutico , Dor Irruptiva/etiologia , Quimioterapia Combinada , Humanos , Neoplasias/complicações , Guias de Prática Clínica como Assunto
11.
Virchows Arch ; 462(4): 481-5, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23443940

RESUMO

Primary meningiomas arising outside the central nervous system are very rare. They have been reported in the head and neck region, in the thorax, the retroperitoneum, and the pelvis. Usually, they behave as slow-growing tumors with a good prognosis. Herein, we report an autopsy case of a 108-year-old woman, known for a right-sided slowly growing lung nodule for 39 years. Death was attributed to cachexia. At post-mortem, a 15-cm mass was present in the right inferior lobe of the lung, associated with an ipsilateral hilar lymphadenopathy, and another 10-cm mass in the liver. Histology revealed a WHO grade III meningioma. No tumor was observed in the cranial cavity. This case illustrates a rare location of meningioma and highlights its biological behavior, with a very slow progression from a most probably benign tumor to a malignant lesion with metastasis over four decades.


Assuntos
Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/patologia , Meningioma/secundário , Idoso , Idoso de 80 Anos ou mais , Autopsia , Feminino , Humanos , Metástase Linfática
12.
Am J Hosp Palliat Care ; 30(8): 786-90, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23324413

RESUMO

UNLABELLED: Palliative sedation (PS) is a treatment option in case of refractory symptoms at the end of life. The emotional impact on nurses and doctors has been widely studied. We explore the experience of family members during a PS procedure. METHOD: An anonymous questionnaire was sent to the closest family members (n = 17) of patients who died while receiving palliative sedation. RESULTS: The response rate was 59% (10 of 17). Nine relatives were sufficiently informed about PS. In all, 70% evaluated the chosen moment for initiation of PS as adequate. All the relatives noticed a significant improvement in the refractory symptom with a mean reduction in the estimated suffering of 6.25 points on a visual analog scale. CONCLUSIONS: Palliative sedation should be performed in the best possible way for the patient and his family in order to efficiently reduce a refractory symptom.


Assuntos
Hipnóticos e Sedativos , Cuidados Paliativos , Família/psicologia , Humanos , Enfermeiras e Enfermeiros , Inquéritos e Questionários
13.
Science ; 338(6107): 659-62, 2012 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-23087001

RESUMO

Typically, pathogens deploy virulence effectors to disable defense. Plants defeat effectors with resistance proteins that guard effector targets. We found that a pathogen exploits a resistance protein by activating it to confer susceptibility in Arabidopsis. The guard mechanism of plant defense is recapitulated by interactions among victorin (an effector produced by the necrotrophic fungus Cochliobolus victoriae), TRX-h5 (a defense-associated thioredoxin), and LOV1 (an Arabidopsis susceptibility protein). In LOV1's absence, victorin inhibits TRX-h5, resulting in compromised defense but not disease by C. victoriae. In LOV1's presence, victorin binding to TRX-h5 activates LOV1 and elicits a resistance-like response that confers disease susceptibility. We propose that victorin is, or mimics, a conventional pathogen virulence effector that was defeated by LOV1 and confers virulence to C. victoriae solely because it incites defense.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis , Ascomicetos/patogenicidade , Proteínas de Ligação a DNA/metabolismo , Proteínas Fúngicas/metabolismo , Micotoxinas/metabolismo , Doenças das Plantas , Imunidade Vegetal , Tiorredoxinas/metabolismo , Fatores de Virulência/metabolismo , Arabidopsis/imunologia , Arabidopsis/metabolismo , Arabidopsis/microbiologia , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Ascomicetos/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Suscetibilidade a Doenças , Mutação , Oxirredução , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Tiorredoxinas/genética , Nicotiana/genética , Nicotiana/metabolismo
15.
Cell Death Differ ; 18(12): 1845-53, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21566665

RESUMO

The ubiquitin-editing enzyme A20 (tumor necrosis factor-α-induced protein 3) serves as a critical brake on nuclear factor κB (NF-κB) signaling. In humans, polymorphisms in or near the A20 gene are associated with several inflammatory disorders, including psoriasis. We show here that epidermis-specific A20-knockout mice (A20(EKO)) develop keratinocyte hyperproliferation, but no signs of skin inflammation, such as immune cell infiltration. However, A20(EKO) mice clearly developed ectodermal organ abnormalities, including disheveled hair, longer nails and sebocyte hyperplasia. This phenotype resembles that of mice overexpressing ectodysplasin-A1 (EDA-A1) or the ectodysplasin receptor (EDAR), suggesting that A20 negatively controls EDAR signaling. We found that A20 inhibited EDAR-induced NF-κB signaling independent from its de-ubiquitinating activity. In addition, A20 expression was induced by EDA-A1 in embryonic skin explants, in which its expression was confined to the hair placodes, known to be the site of EDAR expression. In summary, our data indicate that EDAR-induced NF-κB levels are controlled by A20, which functions as a negative feedback regulator, to assure proper skin homeostasis and epidermal appendage development.


Assuntos
Cisteína Endopeptidases/genética , Epiderme/fisiologia , Homeostase , Peptídeos e Proteínas de Sinalização Intracelular/genética , Queratinócitos/metabolismo , NF-kappa B/metabolismo , Animais , Cisteína Endopeptidases/metabolismo , Cisteína Endopeptidases/fisiologia , Ectodisplasinas/farmacologia , Ectodisplasinas/fisiologia , Receptor Edar/agonistas , Receptor Edar/antagonistas & inibidores , Receptor Edar/metabolismo , Epiderme/patologia , Retroalimentação Fisiológica , Genes Reporter , Células HEK293 , Cabelo/anormalidades , Cabelo/embriologia , Humanos , Hiperplasia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Queratinócitos/fisiologia , Antígeno Ki-67/metabolismo , Luciferases/biossíntese , Luciferases/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fenótipo , Técnicas de Cultura de Tecidos , Proteína 3 Induzida por Fator de Necrose Tumoral alfa , Fator de Necrose Tumoral alfa/farmacologia , Fator de Necrose Tumoral alfa/fisiologia
16.
Crit Rev Oncol Hematol ; 74(1): 61-5, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19446467

RESUMO

Efforts to improve the quality of end-of-life decision-making have emphasized the principle of individual autonomy to better ensure that patients receive care consistent with their preferences. Advance directives (ADs) can be vehicles for in-depth and ongoing discussions among health care professionals, patients, and families. The aim of our study was to identify preferences and values expressed in ADs of 50 elderly patients with cancer. Main concerns of the patients were resuscitation and introduction of artificial nutrition. Very few patients had unrealistic expectation. Preferences about patient's symptom management were quite different from one to another. Content of ADs not only involved life-sustaining technology, but also psychosocial items and religious beliefs and values. All patients designated at least one surrogate. In conclusion, ADs should not be considered simply as another questionnaire, but more as a process to improve communication.


Assuntos
Diretivas Antecipadas , Serviços de Saúde para Idosos , Neoplasias/terapia , Cuidados Paliativos , Preferência do Paciente , Assistência Terminal , Idoso , Idoso de 80 Anos ou mais , Comportamento de Escolha , Comunicação , Feminino , Humanos , Masculino , Neoplasias/psicologia , Autonomia Pessoal , Relações Médico-Paciente , Procurador , Religião , Estudos Retrospectivos
18.
Am J Hosp Palliat Care ; 26(2): 84-8, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19088264

RESUMO

In the case of malignant intestinal obstruction, surgery often carries important mortality and morbidity risks, and feasibility is neither realistic nor reasonable. A total of 4 clinical cases of intestinal obstruction caused by advanced gastrointestinal cancers in their terminal phase are described. The association of analgesics, corticosteroids, antiemetics, and octreotide was effective to relieve symptoms of intestinal obstruction for the remaining lifetime. The insertion of a nasogastric tube was avoided in 3 of 4 cases. Death occurred 51, 56, and 64 days after clinical and radiological diagnosis of irreversible intestinal obstruction. This combination of drugs appears very powerful and well tolerated. The relatively long survival that was observed should encourage future studies of longer half-life somatostatin analogues with no need of continuous infusion or multiple daily injections.


Assuntos
Corticosteroides/uso terapêutico , Analgésicos/uso terapêutico , Fármacos Gastrointestinais/uso terapêutico , Obstrução Intestinal/tratamento farmacológico , Octreotida/uso terapêutico , Assistência Terminal/métodos , Adulto , Idoso , Evolução Fatal , Feminino , Neoplasias Gastrointestinais/complicações , Humanos , Obstrução Intestinal/etiologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Doente Terminal
19.
Epigenetics ; 3(5): 270-80, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19001875

RESUMO

Drug transporters have been implicated in resistance of solid and non-solid tumors to a variety of chemotherapeutic agents. Higher expression of the ABCB1 drug transporter is often observed in drug-resistant tumor cells, although the precise mechanism remains unclear. During selection of MCF-7 cells for survival in increasing concentrations of docetaxel (MCF-7TXT cells), we observed in this study a temporal correlation between the acquisition of docetaxel resistance at selection dose 9 and the increased expression of ABCB1. Both the magnitude of docetaxel resistance and the level of ABCB1 expression then rose as the selection dose was further elevated. We also observed through bisulfite sequencing experiments that the ABCB1 downstream promoter became increasingly methylated following the acquisition of drug resistance (selection doses 10-12). Transcription was solely attributed to the upstream ABCB1 promoter within MCF-7TXT cells at the highest selection dose suggesting that hypermethylation caused a shift in promoter usage. The hypermethylation was also accompanied by regional amplification of chromosome 7 containing the ABCB1 gene and its neighbor ABCB4 but not DBF-4. The amplification of the ABCB1 gene correlated positively both with the hypermethylation of the ABCB1 downstream promoter (r=0.90) and the increased expression of ABCB1 (r=0.78). Moreover demethylation of the ABCB1 downstream promoter induced by 5-aza-2A'deoxycytidine treatment decreased the expression of ABCB1 mRNA in MCF-7TXT cells. Taken together, our findings suggest that the increased expression of ABCB1 upon acquisition of docetaxel resistance in breast tumor cells can be multifactorial, involving both epigenetic changes in promoter usage and regional chromosome amplification.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Neoplasias da Mama/genética , Metilação de DNA , Resistencia a Medicamentos Antineoplásicos/genética , Amplificação de Genes , Regulação Neoplásica da Expressão Gênica , Subfamília B de Transportador de Cassetes de Ligação de ATP , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Docetaxel , Epigênese Genética , Feminino , Expressão Gênica , Humanos , Regiões Promotoras Genéticas , Taxoides/farmacologia , Transcrição Gênica
20.
J Palliat Med ; 11(6): 878-84, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18715180

RESUMO

INTRODUCTION: In geriatrics, most risk factors associated with falls have been identified and management strategies developed accordingly. This is not the case in palliative care. The incidence rate of falls, the consequences related to falls, and other related factors were determined in elderly cancer patients hospitalized for palliative care in an exploratory study. METHODS: All consecutive patients hospitalized with advanced cancer were included over a 1-year period. Each fall was identified and detailed by a routinely collected incident report. Associations between variables and falls were assessed. RESULTS: Mean age of the 198 patients (116 F) was 71.0 +/- 12.1 years. Of these, 36 had a fall at least once. Delirium occurred significantly more often in fallers (p = 0.029). There was a nonsignificant trend for a higher number of prescribed drugs in fallers (n = 8.5 +/- 3.7 versus 7.5 +/- 3.2; p = 0.4) who received significantly more neuroleptics (47.2% versus 29%; p = 0.035). Environmental hazards made little contribution to patients' falls. DISCUSSION: Characteristics of falls in palliative care appear different from those evidenced in geriatric wards. To prevent delirium while prescribing neuroleptic drugs with the greatest caution should help decrease the number of falls in this highly vulnerable group of patients.


Assuntos
Acidentes por Quedas/estatística & dados numéricos , Delírio/complicações , Neoplasias/complicações , Cuidados Paliativos/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Antipsicóticos/administração & dosagem , Antipsicóticos/efeitos adversos , Comorbidade , Delírio/induzido quimicamente , Prescrições de Medicamentos , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Neoplasias/tratamento farmacológico , Fatores de Risco , Índice de Gravidade de Doença
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