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1.
Cureus ; 15(8): e43797, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37731452

RESUMO

Background The study aims to assess knowledge and attitudes toward organ donation among medical school interns and postgraduate residents in a tertiary care hospital in Anand, Gujarat, India. Methodology A cross-sectional study was conducted among 250 medical school interns and residents of Shree Krishna Hospital, a tertiary care hospital in Anand, Gujarat, India, between March 2021 and March 2022 using a paper questionnaire comprising questions regarding attitudes and beliefs toward organ donation. Results Among the 250 participants in this study, 124 (49.6%) were residents, and 126 (50.4%) were interns, with a mean age of 24.18 ± 2.02 years. Of all participants, 88.8% were willing to donate their organs; the main reason was to help people in need. However, the main reason for the refusal to donate organs was the fear of organs being misused/trafficked. Another finding was that 77.2% of the participants had no issue regarding who receives their organs. Only 25.2% of participants had correct knowledge and were aware of the Transplantation of Human Organs Act, 1994 of India, and 66% felt that the current curriculum does not provide sufficient learning experience related to organ donation. Conclusions There was less awareness regarding organ donation, despite the willingness to donate organs. Thus, it is essential to increase awareness through curriculum and various workshops to make the process of pledging organs more accessible among those willing to donate. This will play a significant role in addressing the problem and, in turn, help those in need.

2.
Clin Lung Cancer ; 22(6): 601-606, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34389237

RESUMO

INTRODUCTION: Osimertinib, a third-generation, irreversible, epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), selectively inhibits both EGFR-TKI sensitizing (EGFRm) and EGFR T790M resistance mutations and has demonstrated efficacy in non-small cell lung cancer (NSCLC) CNS metastases. Most patients with EGFRm NSCLC treated with osimertinib will eventually develop resistance. ORCHARD (NCT03944772) is a phase II study aiming to characterize first-line osimertinib resistance and identify post-progression treatments. METHODS: Adults aged ≥ 18 years (Japan ≥ 20 years), with EGFRm locally advanced/metastatic NSCLC will be allocated to one of three groups after first-line osimertinib progression, based on molecular profiling from a post-progression tumor biopsy. Group A will evaluate patients with protocol-determined biomarkers of resistance treated with novel osimertinib combination therapies, Group B will evaluate patients without a detectable protocol-determined biomarker treated with non-biomarker selected therapies that are chemotherapy- or EGFR-TKI-based, and Group C (observational) includes patients with histologically transformed disease, and/or a biomarker with an available therapy not investigated in ORCHARD. Group C patients will be treated as per local practice and followed to assess overall survival. The study's platform design allows for adaptability to include emerging treatments related to novel resistance mechanisms. The primary endpoint is confirmed objective response rate (investigator assessed). Other endpoints are progression-free survival, duration of response, overall survival, pharmacokinetics and safety. CONCLUSIONS: ORCHARD aims to characterize mechanisms of resistance to first-line osimertinib and explore treatments to overcome acquired resistance. The modular design allows for additional biomarker-directed cohorts and treatment options as understanding of osimertinib resistance mechanisms evolves.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Progressão da Doença , Receptores ErbB/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Mutação/genética , Metástase Neoplásica , Adolescente , Adulto , Resistencia a Medicamentos Antineoplásicos , Humanos , Pessoa de Meia-Idade , Adulto Jovem
3.
J Clin Pharm Ther ; 46(5): 1308-1311, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33959987

RESUMO

WHAT IS KNOWN AND OBJECTIVE: A pandemic can strain all aspects of the healthcare system, including the ability to monitor the safety of medication use. Reviewing the adequacy of medication safety practices during the COVID-19 pandemic is critical to informing responses to future pandemics. The purpose of this study was to evaluate medication safety practices at a height of both COVID-19 cases and hydroxychloroquine use. METHODS: This was a multicentre observational point prevalence study. Adult inpatients receiving hydroxychloroquine for COVID-19 between March 22 and 28, 2020 were included. The primary outcome was the percentage of patients receiving appropriate QTc monitoring. Secondary outcomes included QTc prolongation, early discontinuation of hydroxychloroquine and ventricular arrhythmias. RESULTS AND DISCUSSION: A total of 59% (167/284) of patients treated with hydroxychloroquine received appropriate QTc monitoring. QTc prolongation occurred in 25%. Hydroxychloroquine was prematurely discontinued in 1.4% of patients, all due to QTc prolongation. Ventricular arrhythmia occurred in 1.1%. WHAT IS NEW AND CONCLUSION: Medication safety practices were suboptimal with regard to hydroxychloroquine monitoring at the height of the COVID-19 pandemic. Preparation for future pandemics should devote considerable attention to medication safety.


Assuntos
Arritmias Cardíacas/induzido quimicamente , Arritmias Cardíacas/diagnóstico , Tratamento Farmacológico da COVID-19 , Eletrocardiografia/métodos , Hidroxicloroquina/efeitos adversos , Segurança do Paciente/estatística & dados numéricos , Inibidores Enzimáticos/efeitos adversos , Inibidores Enzimáticos/uso terapêutico , Feminino , Humanos , Hidroxicloroquina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Pandemias , Prevalência , SARS-CoV-2
4.
Exp Mol Med ; 53(1): 125-135, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33473144

RESUMO

Monge's disease (chronic mountain sickness (CMS)) is a maladaptive condition caused by chronic (years) exposure to high-altitude hypoxia. One of the defining features of CMS is excessive erythrocytosis with extremely high hematocrit levels. In the Andean population, CMS prevalence is vastly different between males and females, being rare in females. Furthermore, there is a sharp increase in CMS incidence in females after menopause. In this study, we assessed the role of sex hormones (testosterone, progesterone, and estrogen) in CMS and non-CMS cells using a well-characterized in vitro erythroid platform. While we found that there was a mild (nonsignificant) increase in RBC production with testosterone, we observed that estrogen, in physiologic concentrations, reduced sharply CD235a+ cells (glycophorin A; a marker of RBC), from 56% in the untreated CMS cells to 10% in the treated CMS cells, in a stage-specific and dose-responsive manner. At the molecular level, we determined that estrogen has a direct effect on GATA1, remarkably decreasing the messenger RNA (mRNA) and protein levels of GATA1 (p < 0.01) and its target genes (Alas2, BclxL, and Epor, p < 0.001). These changes result in a significant increase in apoptosis of erythroid cells. We also demonstrate that estrogen regulates erythropoiesis in CMS patients through estrogen beta signaling and that its inhibition can diminish the effects of estrogen by significantly increasing HIF1, VEGF, and GATA1 mRNA levels. Taken altogether, our results indicate that estrogen has a major impact on the regulation of erythropoiesis, particularly under chronic hypoxic conditions, and has the potential to treat blood diseases, such as high altitude severe erythrocytosis.


Assuntos
Doença da Altitude/sangue , Eritrócitos/efeitos dos fármacos , Estrogênios/farmacologia , Policitemia/metabolismo , Doença da Altitude/metabolismo , Células Cultivadas , Eritrócitos/metabolismo , Estrogênios/metabolismo , Feminino , Fator de Transcrição GATA1/genética , Fator de Transcrição GATA1/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Masculino , Policitemia/sangue , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
5.
Allergy ; 75(4): 841-852, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31833571

RESUMO

BACKGROUND: Asthma is a complicated chronic inflammatory disorder characterized by airway inflammation and bronchial hyperresponsiveness. Group 2 innate lymphoid cells (ILC2) are tissue-resident innate effector cells that can mediate airway inflammation and hyperresponsiveness through production of IL-5, IL-13 and VEGFA. ILC2 in asthma patients exhibit an activated phenotype. However, molecular pathways that control ILC2 activation are not well understood. METHODS: MYC expression was examined in ILC2 sorted from peripheral blood of healthy controls and asthma patients or cultured with or without activating cytokines. CRISPR knockout technique was used to delete c-Myc in primary murine lung ILC2 or an ILC2 cell line. Cell proliferation was examined, gene expression pattern was profiled by genome-wide microarray analysis, and direct gene targets were identified by Chromatin immunoprecipitation (ChIP). ILC2 responses, airway inflammation and airway hyperresponsiveness were examined in Balb/c mice challenged with Alternaria extracts, with or without treatment with JQ1. RESULTS: ILC2 from asthma patients expressed increased amounts of MYC. Deletion of c-Myc in ILC2 results in reduced proliferation, decreased cytokine production, and reduced expression of many lymphocyte activation genes. ChIP identified Stat6 as a direct gene target of c-Myc in ILC2. In vivo inhibition of c-Myc by JQ1 treatment repressed ILC2 activity and suppressed Alternaria-induced airway inflammation and AHR. CONCLUSION: c-Myc expression is upregulated during ILC2 activation. c-Myc is essential for ILC2 activation and their in vivo pathogenic effects. These findings suggest that targeting c-Myc may unlock novel strategies to combat asthma or asthma exacerbation.


Assuntos
Asma , Linfócitos , Animais , Asma/genética , Citocinas , Humanos , Imunidade Inata , Interleucina-13 , Interleucina-33 , Pulmão , Camundongos , Camundongos Knockout , Proteínas Proto-Oncogênicas c-myc
7.
Allergy Asthma Proc ; 40(3): 138-145, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31018888

RESUMO

Background: Over the past decade, there has been increasing interest and research into understanding the type 2 immune responses by the epithelium-derived cytokines interleukin (IL) 33, IL-25, and thymic stromal lymphopoietin. Innate lymphoid cells (ILC) are a unique family of effector immune cells that functionally resemble T cells but lack clonal distributed antigen receptors. Group 2 ILCs, ILC2s, are known for their capability to secrete proallergic cytokines, including IL-5 and IL-13. ILC2s are enriched at mucosal barriers in lung, gut, and skin, and their activation has been associated with a variety of allergic disorders. Objective: To study the role of ILC2 in different allergic disorders, including allergic rhinitis, asthma, atopic dermatitis, and food allergies. Methods: A MEDLINE search was performed for articles that reported on ILC2 in allergic disorders, including allergic rhinitis, asthma, atopic dermatitis, and food allergies. Results: A review of the literature revealed an important role of ILC2 in various allergic disorders. Conclusion: Identification of ILC2s in patients with allergic rhinitis, asthma, and atopic dermatitis indicates that these cells may represent a new therapeutic target. In this review, we discussed the current understanding of ILC2 biology and its function and regulation in various allergic diseases.


Assuntos
Suscetibilidade a Doenças , Hipersensibilidade/etiologia , Hipersensibilidade/metabolismo , Imunidade Inata , Linfócitos/imunologia , Linfócitos/metabolismo , Alérgenos/imunologia , Animais , Biomarcadores , Citocinas/metabolismo , Humanos , Hipersensibilidade/diagnóstico , Mediadores da Inflamação/metabolismo , Ativação Linfocitária/imunologia
8.
Elife ; 72018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29712619

RESUMO

While targeted therapy against HER2 is an effective first-line treatment in HER2+ breast cancer, acquired resistance remains a clinical challenge. The pseudokinase HER3, heterodimerisation partner of HER2, is widely implicated in the resistance to HER2-mediated therapy. Here, we show that lapatinib, an ATP-competitive inhibitor of HER2, is able to induce proliferation cooperatively with the HER3 ligand neuregulin. This counterintuitive synergy between inhibitor and growth factor depends on their ability to promote atypical HER2-HER3 heterodimerisation. By stabilising a particular HER2 conformer, lapatinib drives HER2-HER3 kinase domain heterocomplex formation. This dimer exists in a head-to-head orientation distinct from the canonical asymmetric active dimer. The associated clustering observed for these dimers predisposes to neuregulin responses, affording a proliferative outcome. Our findings provide mechanistic insights into the liabilities involved in targeting kinases with ATP-competitive inhibitors and highlight the complex role of protein conformation in acquired resistance.


Assuntos
Neoplasias da Mama/metabolismo , Proliferação de Células , Lapatinib/farmacologia , Neuregulina-1/metabolismo , Multimerização Proteica , Receptor ErbB-2/química , Receptor ErbB-3/química , Trifosfato de Adenosina/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Feminino , Humanos , Fosforilação , Conformação Proteica , Inibidores de Proteínas Quinases/farmacologia , Receptor ErbB-2/metabolismo , Receptor ErbB-3/metabolismo , Transdução de Sinais , Células Tumorais Cultivadas
9.
Oncotarget ; 7(32): 51012-51026, 2016 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-27618787

RESUMO

Overexpression of HER2 is an important prognostic marker, and the only predictive biomarker of response to HER2-targeted therapies in invasive breast cancer. HER2-HER3 dimer has been shown to drive proliferation and tumor progression, and targeting of this dimer with pertuzumab alongside chemotherapy and trastuzumab, has shown significant clinical utility. The purpose of this study was to accurately quantify HER2-HER3 dimerisation in formalin fixed paraffin embedded (FFPE) breast cancer tissue as a novel prognostic biomarker.FFPE tissues were obtained from patients included in the METABRIC (Molecular Taxonomy of Breast Cancer International Consortium) study. HER2-HER3 dimerisation was quantified using an improved fluorescence lifetime imaging microscopy (FLIM) histology-based analysis. Analysis of 131 tissue microarray cores demonstrated that the extent of HER2-HER3 dimer formation as measured by Förster Resonance Energy Transfer (FRET) determined through FLIM predicts the likelihood of metastatic relapse up to 10 years after surgery (hazard ratio 3.91 (1.61-9.5), p = 0.003) independently of HER2 expression, in a multivariate model. Interestingly there was no correlation between the level of HER2 protein expressed and HER2-HER3 heterodimer formation. We used a mathematical model that takes into account the complex interactions in a network of all four HER proteins to explain this counterintuitive finding.Future utility of this technique may highlight a group of patients who do not overexpress HER2 protein but are nevertheless dependent on the HER2-HER3 heterodimer as driver of proliferation. This assay could, if validated in a group of patients treated with, for instance pertuzumab, be used as a predictive biomarker to predict for response to such targeted therapies.


Assuntos
Biomarcadores Tumorais/análise , Neoplasias da Mama/patologia , Transferência Ressonante de Energia de Fluorescência/métodos , Microscopia de Fluorescência/métodos , Receptor ErbB-2/análise , Receptor ErbB-3/análise , Adulto , Idoso , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Dimerização , Feminino , Humanos , Estimativa de Kaplan-Meier , Pessoa de Meia-Idade , Modelos Teóricos , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/patologia , Prognóstico , Modelos de Riscos Proporcionais , Receptor ErbB-2/metabolismo , Receptor ErbB-3/metabolismo
11.
Cancer Med ; 4(10): 1461-71, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26211512

RESUMO

Although a raised body mass index (BMI) is associated with increased risk of colorectal cancer (CRC) and recurrence after adjuvant treatment, data in the metastatic setting is limited. We compared overall survival (OS) across BMI groups for metastatic CRC, and specifically examined the effect of BMI within the group of patients treated with targeted therapies (TT). Retrospective data were obtained from the South Australian Registry for mCRC from February 2006 to October 2012. The BMI at first treatment was grouped as underweight <18.5 kg/m(2) , Normal = 18.5 to <25 kg/m(2) , Overweight = 25 to <30 kg/m(2) , Obese I = 30 to <35 kg/m(2) , Obese II ≥35 kg/m(2) . Of 1174 patients, 42 were underweight, 462 overweight, 175 Obese I, and 77 Obese II. The OS was shorter for patients who were underweight and overweight compared to normal (OS 13.7 and 22.3 vs. 24.1 months, respectively, hazard ratio [HR] 2.21 and 1.23). The adjusted median OS was longer for normal versus overweight or obese I patients receiving chemotherapy + targeted therapy (35.7 vs 25.1 or 22.8 months, HR 1.59 and 1.63, respectively) with no difference in OS for chemotherapy alone. On breakdown by type of targeted therapy, overweight and obese I patients had a poorer outcome with Bevacizumab. The BMI is predictive of a poorer outcome for underweight and overweight patients in the whole population. Of those receiving chemotherapy and targeted therapy, BMI is an independent predictor for OS for overweight and obese I patients, specifically for those treated with Bevacizumab. Patients who are overweight or obese (group I) may be a target group for lifestyle and nutrition advice to improve OS with TT.


Assuntos
Antineoplásicos/uso terapêutico , Índice de Massa Corporal , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/mortalidade , Receptores ErbB/antagonistas & inibidores , Terapia de Alvo Molecular/métodos , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Idoso , Austrália/epidemiologia , Neoplasias Colorretais/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Obesidade/epidemiologia , Prognóstico , Estudos Retrospectivos , Magreza/epidemiologia , Resultado do Tratamento
12.
Biochem Soc Trans ; 42(6): 1498-505, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25399560

RESUMO

Breast cancer heterogeneity demands that prognostic models must be biologically driven and recent clinical evidence indicates that future prognostic signatures need evaluation in the context of early compared with late metastatic risk prediction. In pre-clinical studies, we and others have shown that various protein-protein interactions, pertaining to the actin microfilament-associated proteins, ezrin and cofilin, mediate breast cancer cell migration, a prerequisite for cancer metastasis. Moreover, as a direct substrate for protein kinase Cα, ezrin has been shown to be a determinant of cancer metastasis for a variety of tumour types, besides breast cancer; and has been described as a pivotal regulator of metastasis by linking the plasma membrane to the actin cytoskeleton. In the present article, we demonstrate that our tissue imaging-derived parameters that pertain to or are a consequence of the PKC-ezrin interaction can be used for breast cancer prognostication, with inter-cohort reproducibility. The application of fluorescence lifetime imaging microscopy (FLIM) in formalin-fixed paraffin-embedded patient samples to probe protein proximity within the typically <10 nm range to address the oncological challenge of tumour heterogeneity, is discussed.


Assuntos
Neoplasias da Mama/patologia , Proteína Quinase C-alfa/metabolismo , Fatores de Despolimerização de Actina/metabolismo , Neoplasias da Mama/enzimologia , Neoplasias da Mama/metabolismo , Proteínas do Citoesqueleto/metabolismo , Feminino , Transferência Ressonante de Energia de Fluorescência , Humanos , Metástase Neoplásica , Fosforilação , Frações Subcelulares/metabolismo , Especificidade por Substrato , Resultado do Tratamento
13.
Biochem Soc Trans ; 42(4): 831-6, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25109965

RESUMO

Specific inhibition of members of the EGFR (epidermal growth factor receptor) family, particularly EGFR and HER2 (human epidermal growth factor receptor 2), are an important therapeutic strategy in many human cancers. Compared with classical chemotherapy, these targeted therapeutics are very specific and initially effective, but acquired resistance against these targeted therapies is a recurring threat. A growing body of recent work has highlighted a pseudokinase in the EGFR family, HER3, and its ligand, NRG (neuregulin ß1), to be of importance in models of resistant cancers, as well as in patients. In the present article, we describe some of the roles in which HER3 can mediate acquired resistance and discuss the current efforts to target HER3 itself in cancer.


Assuntos
Antineoplásicos/uso terapêutico , Receptores ErbB/metabolismo , Neoplasias/metabolismo , Receptor ErbB-2/metabolismo , Receptor ErbB-3/metabolismo , Resistencia a Medicamentos Antineoplásicos , Receptores ErbB/antagonistas & inibidores , Humanos , Neoplasias/tratamento farmacológico , Receptor ErbB-2/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos
14.
Clin Colorectal Cancer ; 13(2): 87-93, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24373733

RESUMO

BACKGROUND: Whether metastatic colorectal cancer (mCRC) that presents synchronously with the primary lesion behaves differently from mCRC that appears metachronously to the primary disease is not clear. PATIENTS AND METHODS: The South Australian Clinical Registry for mCRC collects data for patients diagnosed after February 2006. Data from 2502 patients, available on October 22, 2012, were analyzed according to stage at initial diagnosis (SAID) to compare outcomes between metachronous tumors (MTs) (stages I, II, III) and synchronous tumors (STs) (stage IV). Overall survival (OS) was calculated from the date of mCRC diagnosis. RESULTS: Patients with ST had more liver-only metastases, and patients with MT had more lung-only, non-lung and non-liver, and non-lung metastases. The median time to recurrence differed significantly according to SAID: stage I, 49.3 mo (n = 29), stage II, 25.2 mo (n = 346) and stage III, 18.4 mo (n = 497). The median OS was longer for patients with MT than for those with ST (19.0 vs.14.9 mo, P = .003). For patients who received any treatment for mCRC, the OS was longer for patients with MT than for those with ST (19.2 vs. 15.3 mo, P = .005). In patients who received only chemotherapy for mCRC, the median OS was longer for patients with MT than for those with ST (15.2 vs. 9.9 mo, P < .0001). No difference in OS between the MT and ST groups for patients who did not receive treatment for mCRC (1.6 vs. 2.6 mo; P = .95). CONCLUSION: Patients with MT have a longer OS than those with ST, independent of treatment. Classification of patients according to whether they have metachronous or synchronous presentation of mCRC is prognostic. These results may add further support for population screening with the aim to reduce de novo metastatic disease.


Assuntos
Neoplasias Colorretais/patologia , Neoplasias Primárias Múltiplas/patologia , Segunda Neoplasia Primária/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Neoplasias Primárias Múltiplas/epidemiologia , Neoplasias Primárias Múltiplas/terapia , Segunda Neoplasia Primária/epidemiologia , Segunda Neoplasia Primária/terapia , Prognóstico , Sistema de Registros , Austrália do Sul/epidemiologia , Taxa de Sobrevida , Adulto Jovem
15.
Cancer Manag Res ; 5: 387-400, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24294007

RESUMO

Targeted therapies have improved the survival of patients with advanced colorectal cancer (CRC). However, further improvements in patient outcomes may be gained by the development of predictive biomarkers in order to select individuals who are most likely to benefit from treatment, thus personalizing treatment. Using the epidermal growth-factor receptor (EGFR) pathway, we discuss the existing and potential predictive biomarkers in clinical development for use with EGFR-targeted agents in metastatic CRC. The data and technological issues surrounding such biomarkers as expression of EGFR or its family members or ligands, KRAS-, NRAS-, and BRAF-mutation status, PI3K/PTEN expression, and imaging and clinical biomarkers, such as rash and hypomagnesemia, are summarized. Although the discovery of KRAS mutations has improved patient selection for EGFR-targeted treatments, further biomarkers are required, especially for those patients who exhibit KRAS mutations rather than the wild-type gene.

16.
Case Rep Infect Dis ; 2013: 676340, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24490092

RESUMO

Pyogenic liver abscess (PLA) is a potentially fatal disease. Klebsiella pneumoniae (K. pneumoniae) has replaced Escherichia coli (E. coli) as the predominant causative organism for pyogenic liver abscess. Over the years a unique form of community-acquired invasive K. pneumoniae infection of the liver has been well described in Southeast Asia. This has recently been linked to a virulent hypermucoviscous K. pneumoniae phenotype and to a specific genotype, rmpA positive. To our knowledge, we report the first case of PLA with bacteremia and meningitis in a Guyanese patient with the presence of rmpA-positive K. pneumoniae with laboratory evidence in North America.

17.
BMC Bioinformatics ; 12: 403, 2011 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-22011170

RESUMO

BACKGROUND: Inferring molecular pathway activity is an important step towards reducing the complexity of genomic data, understanding the heterogeneity in clinical outcome, and obtaining molecular correlates of cancer imaging traits. Increasingly, approaches towards pathway activity inference combine molecular profiles (e.g gene or protein expression) with independent and highly curated structural interaction data (e.g protein interaction networks) or more generally with prior knowledge pathway databases. However, it is unclear how best to use the pathway knowledge information in the context of molecular profiles of any given study. RESULTS: We present an algorithm called DART (Denoising Algorithm based on Relevance network Topology) which filters out noise before estimating pathway activity. Using simulated and real multidimensional cancer genomic data and by comparing DART to other algorithms which do not assess the relevance of the prior pathway information, we here demonstrate that substantial improvement in pathway activity predictions can be made if prior pathway information is denoised before predictions are made. We also show that genes encoding hubs in expression correlation networks represent more reliable markers of pathway activity. Using the Netpath resource of signalling pathways in the context of breast cancer gene expression data we further demonstrate that DART leads to more robust inferences about pathway activity correlations. Finally, we show that DART identifies a hypothesized association between oestrogen signalling and mammographic density in ER+ breast cancer. CONCLUSIONS: Evaluating the consistency of prior information of pathway databases in molecular tumour profiles may substantially improve the subsequent inference of pathway activity in clinical tumour specimens. This de-noising strategy should be incorporated in approaches which attempt to infer pathway activity from prior pathway models.


Assuntos
Algoritmos , Neoplasias/genética , Mapas de Interação de Proteínas , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Simulação por Computador , Feminino , Perfilação da Expressão Gênica , Humanos , Neoplasias Pulmonares/genética , Mamografia , Transdução de Sinais
18.
Chemphyschem ; 12(3): 442-61, 2011 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-21328516

RESUMO

Herein we discuss how FRET imaging can contribute at various stages to delineate the function of the proteome. Therefore, we briefly describe FRET imaging techniques, the selection of suitable FRET pairs and potential caveats. Furthermore, we discuss state-of-the-art FRET-based screening approaches (underpinned by protein interaction network analysis using computational biology) and preclinical intravital FRET-imaging techniques that can be used for functional validation of candidate hits (nodes and edges) from the network screen, as well as measurement of the efficacy of perturbing these nodes/edges by short hairpin RNA (shRNA) and/or small molecule-based approaches.


Assuntos
Transferência Ressonante de Energia de Fluorescência/métodos , Neoplasias/metabolismo , Mapeamento de Interação de Proteínas , Proteínas/química , Biologia Computacional , Corantes Fluorescentes/química , Humanos , Domínios e Motivos de Interação entre Proteínas , Proteínas/metabolismo
19.
FASEB J ; 24(12): 4744-55, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20682838

RESUMO

Ligand-induced dimerization of the epidermal growth factor receptor (ErbB-1/EGFR) involves conformational changes that expose an extracellular dimerization interface. Subsequent alterations within the cytoplasmic kinase domain, which culminate in tyrosine phosphorylation, are less understood. Our study addressed this question by using two strategies: a chimeric receptor approach employed ErbB-3, whose defective kinase domain was replaced by the respective part of EGFR. The implanted full-length kinase, unlike its subdomains, conferred dimerization and catalysis. The data infer that the kinase function of EGFR is restrained by the carboxyl tail; once grafted distally to the ectopic tail of ErbB-3, the kinase domain acquires quasi-dimerization and activation. In an attempt to alternatively refold the cytoplasmic tail, our other approach employed kinase inhibitors. Biophysical measurements and covalent cross-linking analyses showed that inhibitors targeting the active conformation of EGFR, in contrast to a compound recognizing the inactive conformation, induce quasi-dimers in a manner similar to the chimeric ErbB-3 molecule. Collectively, these observations unveil kinase domain-mediated quasi-dimers, which are regulated by an autoinhibitory carboxyl tail. On the basis of these observations, we propose that quasi-dimers precede formation of ligand-induced, fully active dimers, which are stabilized by both extracellular and intracellular receptor-receptor interactions.


Assuntos
Receptores ErbB/metabolismo , Fosfotransferases/metabolismo , Receptor ErbB-3/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Animais , Células CHO , Cricetinae , Cricetulus , Receptores ErbB/genética , Transferência Ressonante de Energia de Fluorescência , Mutagênese Sítio-Dirigida , Fosfotransferases/genética , Multimerização Proteica/genética , Estrutura Terciária de Proteína , Receptor ErbB-3/genética , Proteínas Recombinantes de Fusão/genética
20.
Target Oncol ; 4(3): 235-52, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19756916

RESUMO

Genomics and proteomics will improve outcome prediction in cancer and have great potential to help in the discovery of unknown mechanisms of metastasis, ripe for therapeutic exploitation. Current methods of prognosis estimation rely on clinical data, anatomical staging and histopathological features. It is hoped that translational genomic and proteomic research will discriminate more accurately than is possible at present between patients with a good prognosis and those who carry a high risk of recurrence. Rational treatments, targeted to the specific molecular pathways of an individual's high-risk tumor, are at the core of tailored therapy. The aim of targeted oncology is to select the right patient for the right drug at precisely the right point in their cancer journey. Optical proteomics uses advanced optical imaging technologies to quantify the activity states of and associations between signaling proteins by measuring energy transfer between fluorophores attached to specific proteins. Förster resonance energy transfer (FRET) and fluorescence lifetime imaging microscopy (FLIM) assays are suitable for use in cell line models of cancer, fresh human tissues and formalin-fixed paraffin-embedded tissue (FFPE). In animal models, dynamic deep tissue FLIM/FRET imaging of cancer cells in vivo is now also feasible. Analysis of protein expression and post-translational modifications such as phosphorylation and ubiquitination can be performed in cell lines and are remarkably efficiently in cancer tissue samples using tissue microarrays (TMAs). FRET assays can be performed to quantify protein-protein interactions within FFPE tissue, far beyond the spatial resolution conventionally associated with light or confocal laser microscopy. Multivariate optical parameters can be correlated with disease relapse for individual patients. FRET-FLIM assays allow rapid screening of target modifiers using high content drug screens. Specific protein-protein interactions conferring a poor prognosis identified by high content tissue screening will be perturbed with targeted therapeutics. Future targeted drugs will be identified using high content/throughput drug screens that are based on multivariate proteomic assays. Response to therapy at a molecular level can be monitored using these assays while the patient receives treatment: utilizing re-biopsy tumor tissue samples in the neoadjuvant setting or by examining surrogate tissues. These technologies will prove to be both prognostic of risk for individuals when applied to tumor tissue at first diagnosis and predictive of response to specifically selected targeted anticancer drugs. Advanced optical assays have great potential to be translated into real-life benefit for cancer patients.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias/diagnóstico , Neoplasias/terapia , Medicina de Precisão , Proteômica , Humanos , Neoplasias/metabolismo , Prognóstico
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