968 resultados para HYPOXIA-INDUCED ANAPYREXIA


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Despite advances in anti-emetic therapy, chemotherapy-induced nausea and vomiting (CINV) still poses a significant burden to patients undergoing chemotherapy. Nausea, in particular, is still highly prevalent in this population. Ginger has been traditionally used as a folk remedy for gastrointestinal complaints and has been suggested as a viable adjuvant treatment for nausea and vomiting in the cancer context. Substantial research has revealed ginger to possess properties that could exert multiple beneficial effects on chemotherapy patients who experience nausea and vomiting. Bioactive compounds within the rhizome of ginger, particularly the gingerol and shogaol class of compounds, interact with several pathways that are directly implicated in CINV in addition to pathways that could play secondary roles by exacerbating symptoms. These properties include 5-HT3, substance P and acetylcholine receptor antagonism; anti-inflammatory properties; and modulation of cellular redox signalling, vasopressin release, gastrointestinal motility, and gastric emptying rate. This review outlines these proposed mechanisms by discussing the results of clinical, in vitro and animal studies both within the chemotherapy context and in other relevant fields. The evidence presented in this review indicates that ginger possesses multiple properties that could be beneficial in reducing chemotherapy-induced nausea and vomiting.

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Purpose This study investigated the efficacy and safety of cryotherapy, in the form of frozen gel gloves, in relation to docetaxel-induced hand and fingernail toxicities. Patients and methods After piloting with 21 patients, a consecutive series sample of patients (n=53) prescribed docetaxel every three weeks, for a minimum of three cycles, was enrolled in this randomised control trial. Participants acted as their own control, with the frozen gel glove worn on one randomised hand for 15 minutes prior to infusion, for the duration of the infusion, and for 15 minutes of after completion of treatment. Hand and nail toxicities were evaluated by two blinded assessors according to CTCAE.v4 criteria. To assess the potential for cross-infection of multi-use gloves, microbial culture and sensitivity swabs were taken of each glove at every tenth use. Results Of the 53 participants enrolled in the main study, 21 provided evaluable data. There was a 60% withdrawal rate due to patient discomfort with the intervention. The mean incidence and severity of toxicities in all evaluable cycles in control and intervention hands respectively were erythroderma Grade 1 (5%/5%); nail discolouration Grade 1 (81%/67%); nail loss Grade 1 (19%/19%) and nail ridging Grade 1 (57%/57%). No significant differences were determined between hand conditions in terms of time to event, nor in terms of toxicity in gloved and non-gloved hands. Conclusion While cryotherapy in the form of frozen gloves for the cutaneous toxicities associated with docetaxel is safe, its limited efficacy, patient discomfort and some logistical issues preclude its use in our clinical setting.

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The reversible posterior leukoencephalopathy syndrome (RPLES) is a condition characterised by reversible neurological and radiological findings that has been associated with use of immunosuppressive, chemotherapeutic and more recently novel targeted therapies. We describe the case of a 50-year-old woman with advanced non-small cell lung cancer who developed status epilepticus shortly after receiving cisplatin and gemcitabine chemotherapy. The clinical, radiological and EEG findings during and post event are presented and are in keeping with a diagnosis of RPLES. Early recognition of this rare syndrome, supportive management and withdrawal of the offending agent appear to result in a reversal of the manifestations described. © 2007 Elsevier Ireland Ltd. All rights reserved.

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Purpose Contrast adaptation has been speculated to be an error signal for emmetropization. Myopic children exhibit higher contrast adaptation than emmetropic children. This study aimed to determine whether contrast adaptation varies with the type of text viewed by emmetropic and myopic young adults. Methods Baseline contrast sensitivity was determined in 25 emmetropic and 25 spectacle-corrected myopic young adults for 0.5, 1.2, 2.7, 4.4, and 6.2 cycles per degree (cpd) horizontal sine wave gratings. The adults spent periods looking at a 6.2 cpd high-contrast horizontal grating and reading lines of English and Chinese text (these texts comprised 1.2 cpd row and 6 cpd stroke frequencies). The effects of these near tasks on contrast sensitivity were determined, with decreases in sensitivity indicating contrast adaptation. Results Contrast adaptation was affected by the near task (F2,672 = 43.0; P < 0.001). Adaptation was greater for the grating task (0.13 ± 0.17 log unit, averaged across all frequencies) than reading tasks, but there was no significant difference between the two reading tasks (English 0.05 ± 0.13 log unit versus Chinese 0.04 ± 0.13 log unit). The myopic group showed significantly greater adaptation (by 0.04, 0.04, and 0.05 log units for English, Chinese, and grating tasks, respectively) than the emmetropic group (F1,48 = 5.0; P = 0.03). Conclusions In young adults, reading Chinese text induced similar contrast adaptation as reading English text. Myopes exhibited greater contrast adaptation than emmetropes. Contrast adaptation, independent of text type, might be associated with myopia development.

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Purpose Women who experience cancer treatment-induced menopause are at risk of long-term chronic morbidity. This risk can be prevented or offset with adherence to health promotion and risk reduction guidelines. The purpose of this study was to explore health behaviours in younger female survivors of cancer and the variables (quality of life and psychological distress) believed to moderate health behaviours. Design Cross-sectional survey of a convenience sample of women (n = 85) in southeast Queensland. Methods Health behaviour and health status were elicited with items from the Australian Health Survey and the Behavioural Risk Factor Surveillance System. The WHO Quality of Life (Brief) measured participants’ self-reported quality of life and their satisfaction with their health. The Brief Symptom Inventory-18 measured psychological distress. Findings Higher self-reported health status was associated with regular exercise and better quality of life. However, a substantial proportion of participants did not engage in the physical activity, dietary or cervical screening practices recommended by Australian guidelines. Conclusions The participants require education regarding the benefits of diet, exercise, weight loss and decreased alcohol intake, as well as information on future health risks and possible comorbidities. These education sessions could be addressed by a nurse-led health promotion model of care at the time of discharge or in the community.

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Introduction: Malignant pleural mesothelioma (MPM) is a rapidly fatal malignancy that is increasing in incidence. The caspase 8 inhibitor FLIP is an anti-apoptotic protein over-expressed in several cancer types including MPM. The histone deacetylase (HDAC) inhibitor Vorinostat (SAHA) is currently being evaluated in relapsed mesothelioma. We examined the roles of FLIP and caspase 8 in regulating SAHA-induced apoptosis in MPM. Methods: The mechanism of SAHA-induced apoptosis was assessed in 7 MPM cell lines and in a multicellular spheroid model. SiRNA and overexpression approaches were used, and cell death was assessed by flow cytometry, Western blotting and clonogenic assays. Results: RNAi-mediated FLIP silencing resulted in caspase 8-dependent apoptosis in MPM cell line models. SAHA potently down-regulated FLIP protein expression in all 7 MPM cell lines and in a multicellular spheroid model of MPM. In 6/7 MPM cell lines, SAHA treatment resulted in significant levels of apoptosis induction. Moreover, this apoptosis was caspase 8-dependent in all six sensitive cell lines. SAHA-induced apoptosis was also inhibited by stable FLIP overexpression. In contrast, down-regulation of HR23B, a candidate predictive biomarker for HDAC inhibitors, significantly inhibited SAHA-induced apoptosis in only 1/6 SAHA-sensitive MPM cell lines. Analysis of MPM patient samples demonstrated significant inter-patient variations in FLIP and caspase 8 expressions. In addition, SAHA enhanced cisplatin-induced apoptosis in a FLIP-dependent manner. Conclusions: These results indicate that FLIP is a major target for SAHA in MPM and identifies FLIP, caspase 8 and associated signalling molecules as candidate biomarkers for SAHA in this disease. © 2011 Elsevier Ltd. All rights reserved.

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Reactive oxygen species (ROS) form as a natural by-product of the normal metabolism of oxygen and play important roles within the cell. Under normal circumstances the cell is able to maintain an adequate homeostasis between the formation of ROS and its removal through particular enzymatic pathways or via antioxidants. If however, this balance is disturbed a situation called oxidative stress occurs. Critically, oxidative stress plays important roles in the pathogenesis of many diseases, including cancer. Epigenetics is a process where gene expression is regulated by heritable mechanisms that do not cause any direct changes to the DNA sequence itself, and disruption of epigenetic mechanisms has important implications in disease. Evidence is emerging that histone deacetylases (HDACs) play decisive roles in regulating important cellular oxidative stress pathways including those involved with sensing oxidative stress and those involved with regulating the cellular response to oxidative stress. In particular aberrant regulation of these pathways by HDACs may play critical roles in cancer progression. In this review we discuss the current evidence linking epigenetics and oxidative stress and cancer, using chronic obstructive pulmonary disease and non-small cell lung cancer to illustrate the importance of epigenetics on these pathways within these disease settings. © 2009 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

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Due to their inherently hypoxic environment, cancer cells often resort to glycolysis, or the anaerobic breakdown of glucose to form ATP to provide for their energy needs, known as the Warburg effect. At the same time, overexpression of the insulin receptor in non-small cell lung cancer (NSCLC) is associated with an increased risk of metastasis and decreased survival. The uptake of glucose into cells is carried out via glucose transporters or GLUTs. Of these, GLUT-4 is essential for insulin-stimulated glucose uptake. Following treatment with the epigenetic targeting agents histone deacetylase inhibitors (HDACi), GLUT-3 and GLUT-4 expression were found to be induced in NSCLC cell lines, with minimal responses in transformed normal human bronchial epithelial cells (HBECs). Similar results for GLUT-4 were observed in cells derived from liver, muscle, kidney and pre-adipocytes. Bioinformatic analysis of the promoter for GLUT-4 indicates that it may also be regulated by several chromatin binding factors or complexes including CTCF, SP1 and SMYD3. Chromatin immunoprecipitation studies demonstrate that the promoter for GLUT-4 is dynamically remodeled in response to HDACi. Overall, these results may have value within the clinical setting as (a) it may be possible to use this to enhance fluorodeoxyglucose (18F) positron emission tomography (FDG-PET) imaging sensitivity; (b) it may be possible to target NSCLC through the use of HDACi and insulin mediated uptake of the metabolic targeting drugs such as 2-deoxyglucose (2-DG); or (c) enhance or sensitize NSCLC to chemotherapy. © 2011 by the authors; licensee MDPI, Basel, Switzerland.

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Recent studies have demonstrated that angiogenesis and suppressed cell- mediated immunity (CMI) play a central role in the pathogenesis of malignant disease facilitating tumour growth, invasion and metastasis. In the majority of tumours, the malignant process is preceded by a pathological condition or exposure to an irritant which itself is associated with the induction of angiogenesis and/or suppressed CMI. These include: cigarette smoking, chronic bronchitis and lung cancer; chronic oesophagitis and oesophageal cancer; chronic viral infections such as human papilloma virus and ano-genital cancers, chronic hepatitis B and C and hepatocellular carcinoma, and Epstein- Barr virus (EBV) and lymphomas; chronic inflammatory conditions such as Crohn's disease and ulcerative colitis and colorectal cancer; asbestos exposure and mesothelioma and excessive sunlight exposure/sunburn and malignant melanoma. Chronic exposure to growth factors (insulin-like growth factor-I in acromegaly), mutations in tumour suppressor genes (TP53 in Li Fraumeni syndrome) and long-term exposure to immunosuppressive agents (cyclosporin A) may also give rise to similar environments and are associated with the development of a range of solid tumours. The increased blood supply would facilitate the development and proliferation of an abnormal clone or clones of cells arising as the result of: (a) an inherited genetic abnormality; and/or (b) acquired somatic mutations, the latter due to local production and/or enhanced delivery of carcinogens and mutagenic growth factors. With progressive detrimental mutations and growth-induced tumour hypoxia, the transformed cell, to a lesser or greater extent, may amplify the angiogenic process and CMI suppression, thereby facilitating further tumour growth and metastasis. There is accumulating evidence that long-term treatment with cyclo-oxygenase inhibitors (aspirin and indomethacin), cytokines such as interferon-α, anti-oestrogens (tamoxifen and raloxifene) and captopril significantly reduces the incidence of solid tumours such as breast and colorectal cancer. These agents are anti-angiogenic and, in the case of aspirin, indomethacin and interferon-α have proven immunomodulatory effects. Collectively these observations indicate that angiogenesis and suppressed CMI play a central role in the development and progression of malignant disease. (C) 2000 Elsevier Science Ltd.

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We hypothesized that normal human mesothelial cells acquire resistance to asbestos-induced toxicity via induction of one or more epidermal growth factor receptor (EGFR) - linked survival pathways (phosphoinositol-3-kinase/AKT/ mammalian target of rapamycin and extracellular signal - regulated kinase [ERK] 1/2) during simian virus 40 (SV40) transformation and carcinogenesis. Both isolated HKNM-2 mesothelial cells and a telomerase-immortalized mesothelial line (LP9/TERT-1) were more sensitive to crocidolite asbestos toxicity than an SV40 Tag-immortalized mesothelial line (MET5A) and malignant mesothelioma cell lines (HMESO and PPM Mill). Whereas increases in phosphorylation of AKT (pAKT) were observed in MET5A cells in response to asbestos, LP9/TERT-1 cells exhibited dose-related decreases in pAKT levels. Pretreatment with an EGFR phosphorylation or mitogen-activated protein kinase kinase 1/2 inhibitor abrogated asbestos-induced phosphorylated ERK (pERK) 1/2 levels in both LP9/TERT-1 and MET5A cells as well as increases in pAKT levels in MET5A cells. Transient transfection of small interfering RNAs targeting ERK1, ERK2, or AKT revealed that ERK1/2 pathways were involved in cell death by asbestos in both cell lines. Asbestos-resistant HMESO or PPM Mill cells with high endogenous levels of ERKs or AKT did not show dose-responsive increases in pERK1/ERK1, pERK2/ERK2, or pAKT/AKT levels by asbestos. However, small hairpin ERK2 stable cell lines created from both malignant mesothelioma lines were more sensitive to asbestos toxicity than shERK1 and shControl lines, and exhibited unique, tumor-specific changes in endogenous cell death - related gene expression. Our results suggest that EGFR phosphorylation is causally linkedto pERK and pAKT activation by asbestos in normal and SV40 Tag - immortalized human mesothelial cells. They also indicate that ERK2 plays a role in modulating asbestos toxicity by regulating genes critical to cell injury and survival that are differentially expressed in human mesotheliomas.

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Hypoxia-inducible factor (HIF)-1α is the regulatory subunit of HIF-1 that is stabilized under hypoxic conditions. Under different circumstances, HIF-1α may promote both tumorigenesis and apoptosis. There is conflicting data on the importance of HIF-1α as a prognostic factor. This study evaluated HIF-1α expression in 172 consecutive patients with stage I-IIIA non small cell lung cancer (NSCLC) using standard immunohistochemical techniques. The extent of HIF-1α nuclear immunostaining was determined using light microscopy and the results were analyzed using the median (5%) as a low cut-point and 60% as a high positive cut-point. Using the low cut-point, positive associations were found with epidermal growth factor receptor (EGFR; p = 0.01), matrix metalloproteinase (MMP)-9 (p = 0.003), membranous (p < 0.001) and perinuclear (p = 0.004) carbonic anhydrase (CA) IX, pS3 (p = 0.008), T-stage (p = 0.042), tumor necrosis (TN; p < 0.001) and squamous histology (p < 0.001). No significant association was found with Bcl-2 or either N- or overall TMN stage or prognosis. When the high positive cut-point was used, HIF-1α was associated with a poor prognosis (p = 0.034). In conclusion, the associations with EGFR, MMP-9, p53 and CA IX suggest that these factors may either regulate or be regulated by HIF-1α. The association with TN and squamous-type histology, which is relatively more necrotic than other NSCLC types, reflects the role of hypoxia in the regulation of HIF-1α. The prognostic data may reflect a change in the behavior of HIF-1α in increasingly hypoxic environments. © 2004 Wiley-Liss, Inc.

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Purpose To evaluate carbonic anhydrase (CA) IX as a surrogate marker of hypoxia and investigate the prognostic significance of different patterns of expression in non-small-cell lung cancer (NSCLC). Methods Standard immunohistochemical techniques were used to study CA IX expression in 175 resected NSCLC tumors. CA IX expression was determined by Western blotting in A549 cell lines grown under normoxic and hypoxic conditions. Measurements from microvessels to CA IX positivity were obtained. Results CA IX immunostaining was detected in 81.8% of patients. Membranous (m) (P = .005), cytoplasmic (c) (P = .018), and stromal (P < .001) CA IX expression correlated with the extent of tumor necrosis (TN). The mean distance from vascular endothelium to the start of tumor cell positivity was 90 μm, which equates to an oxygen pressure of 5.77 mmHg. The distance to blood vessels from individual tumor cells or tumor cell clusters was greater if they expressed mCA IX than if they did not (P < .001). Hypoxic exposure of A549 cells for 16 hours enhanced CAIX expression in the nuclear and cytosolic extracts. Perinuclear (p) CA IX (P = .035) was associated with a poor prognosis. In multivariate analysis, pCA IX (P = .004), stage (P = .001), platelet count (P = .011), sex (P = .027), and TN (P = .035) were independent poor prognostic factors. Conclusion These results add weight to the contention that mCA IX is a marker of tumor cell hypoxia. The absence of CA IX staining close to microvessels suggests that these vessels are functionally active. pCA IX expression is representative of an aggressive phenotype. © 2003 by American Society of Clinical Oncology.

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Tumor hypoxia has been recognized to confer resistance to anticancer therapy since the early 20th century. More recently, its fundamental role in tumorigenesis has been established. Hypoxia-inducible factor (HIF)-1 has been identified as an important transcription factor that mediates the cellular response to hypoxia, promoting both cellular survival and apoptosis under different conditions. Increased tumor cell expression of this transcription factor promotes tumor growth In vivo and is associated with a worse prognosis in patients with non-small-cell lung cancer (NSCLC) undergoing tumor resection. The epidermal growth factor receptor (EGFR) promotes tumor cell proliferation and anglogenesis and inhibits apoptosis. Epidermal growth factor receptor expression increases in a stepwise manner during tumorigenesis and is overexpressed in > 50% of NSCLC tumors. This review discusses the reciprocal relationship between tumor cell hypoxia and EGFR. Recent studies suggest that hypoxia induces expression of EGFR and its ligands. In return, EGFR might enhance the cellular response to hypoxia by increasing expression of HIF-1α, and so act as a survival factor for hypoxic cancer cells. Immunohistochemical studies on a series of resected NSCLC tumors add weight to this contention by demonstrating a close association between expression of EGFR, HIF-1α, and:1 of HIF-1's target proteins, carbonic anhydrase IX. In this article we discuss emerging treatment strategies for NSCLC that target HIF-1, HIF-1 transcriptional targets, and EGFR.

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We found that procaspase 8 was overexpressed in non-small-cell lung cancers (NSCLCs) compared with matched normal tissues. The caspase 8 inhibitor FLICE-inhibitory protein (FLIP) was also overexpressed in the majority of NSCLCs. Silencing FLIP induced caspase 8 activation and apoptosis in NSCLC cell lines, but not in normal lung cell lines. Apoptosis induced by FLIP silencing was mediated by the TRAIL death receptors DR4 and DR5, but was not dependent on ligation of the receptors by TRAIL. Furthermore, the apoptosis induced by FLIP silencing was dependent on the overexpression of procaspase 8 in NSCLC cells. Moreover, in NSCLC cells, but not in normal cells, FLIP silencing induced co-localization of DR5 and ceramide, and disruption of this co-localization abrogated apoptosis. FLIP silencing supra-additively increased TRAIL-induced apoptosis of NSCLC cells; however, normal lung cells were resistant to TRAIL, even when FLIP was silenced. Importantly, FLIP silencing sensitized NSCLC cells but not normal cells to chemotherapy in vitro, and silencing FLIP in vivo retarded NSCLC xenograft growth and enhanced the anti-tumour effects of cisplatin. Collectively, our results suggest that due to frequent procaspase 8 overexpression, NSCLCs may be particularly sensitive to FLIP-targeted therapies.

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Many examples of extreme virus resistance and posttranscriptional gene silencing of endogenous or reporter genes have been described in transgenic plants containing sense or antisense transgenes. In these cases of either cosuppression or antisense suppression, there appears to be induction of a surveillance system within the plant that specifically degrades both the transgene and target RNAs. We show that transforming plants with virus or reporter gene constructs that produce RNAs capable of duplex formation confer virus immunity or gene silencing on the plants. This was accomplished by using transcripts from one sense gene and one antisense gene colocated in the plant genome, a single transcript that has self-complementarity, or sense and antisense transcripts from genes brought together by crossing. A model is presented that is consistent with our data and those of other workers, describing the processes of induction and execution of posttranscriptional gene silencing.