156 research outputs found
Assessment of circulating biomarkers for potential pharmacodynamic utility in patients with lymphoma
Cytokeratin 18 in plasma of patients with gastrointestinal adenocarcinoma as a biomarker of tumour response
BACKGROUND: Plasma biomarkers may be particularly useful as a predictor or early marker of clinical response to treatment in addition to radiological imaging. Cytokeratin 18 (CK18) is an epithelial-specific cytokeratin that undergoes cleavage by caspases during apoptosis. Measurement of caspase-cleaved (CK18-Asp396) or total cytokeratin 18 (CK18) from epithelial-derived tumours could be a simple, non-invasive way to monitor or predict responses to treatment. METHODS: Soluble plasma CK18-Asp396 and CK18 were measured by ELISA from 73 patients with advanced gastrointestinal adenocarcinomas before treatment and during chemotherapy, as well as 100 healthy volunteers. RESULTS: Both CK18-Asp396 and total CK18 plasma levels were significantly higher in patients compared with the healthy volunteers (P = 0.015, P < 0.001). The total CK18 baseline plasma levels before treatment were significantly higher (P = 0.009) in patients who develop progressive disease than those who achieve partial response or stable disease and this correlation was confirmed in an independent validation set. The peak plasma levels of CK18 occurring in any cycle following treatment were also found to be associated with tumour response, but peak levels of CK18-Asp396 did not reach significance (P = 0.01, and P = 0.07, respectively). CONCLUSION: Plasma levels CK18 are a potential marker of tumour response in patients with advanced gastrointestinal malignancy
An Intense and Short-Lasting Burst of Neutrophil Activation Differentiates Early Acute Myocardial Infarction from Systemic Inflammatory Syndromes
BACKGROUND: Neutrophils are involved in thrombus formation. We investigated whether specific features of neutrophil activation characterize patients with acute coronary syndromes (ACS) compared to stable angina and to systemic inflammatory diseases. METHODS AND FINDINGS: The myeloperoxidase (MPO) content of circulating neutrophils was determined by flow cytometry in 330 subjects: 69 consecutive patients with acute coronary syndromes (ACS), 69 with chronic stable angina (CSA), 50 with inflammation due to either non-infectious (acute bone fracture), infectious (sepsis) or autoimmune diseases (small and large vessel systemic vasculitis, rheumatoid arthritis). Four patients have also been studied before and after sterile acute injury of the myocardium (septal alcoholization). One hundred thirty-eight healthy donors were studied in parallel. Neutrophils with normal MPO content were 96% in controls, >92% in patients undergoing septal alcoholization, 91% in CSA patients, but only 35 and 30% in unstable angina and AMI (STEMI and NSTEMI) patients, compared to 80%, 75% and 2% of patients with giant cell arteritis, acute bone fracture and severe sepsis. In addition, in 32/33 STEMI and 9/21 NSTEMI patients respectively, 20% and 12% of neutrophils had complete MPO depletion during the first 4 hours after the onset of symptoms, a feature not observed in any other group of patients. MPO depletion was associated with platelet activation, indicated by P-selectin expression, activation and transactivation of leukocyte β2-integrins and formation of platelet neutrophil and -monocyte aggregates. The injection of activated platelets in mice produced transient, P-selectin dependent, complete MPO depletion in about 50% of neutrophils. CONCLUSIONS: ACS are characterized by intense neutrophil activation, like other systemic inflammatory syndromes. In the very early phase of acute myocardial infarction only a subpopulation of neutrophils is massively activated, possibly via platelet-P selectin interactions. This paroxysmal activation could contribute to occlusive thrombosis
Effectiveness and cost-effectiveness of serum B-type natriuretic peptide testing and monitoring in patients with heart failure in primary and secondary care:an evidence synthesis, cohort study and cost-effectiveness mode
Background: Heart failure (HF) affects around 500,000 people in the UK. HF medications are frequently underprescribed and B-type natriuretic peptide (BNP)-guided therapy may help to optimise treatment. Objective: To evaluate the clinical effectiveness and cost-effectiveness of BNP-guided therapy compared with symptom-guided therapy in HF patients. Design: Systematic review, cohort study and cost-effectiveness model. Setting: A literature review and usual care in the NHS. Participants: (a) HF patients in randomised controlled trials (RCTs) of BNP-guided therapy; and (b) patients having usual care for HF in the NHS. Interventions: Systematic review: BNP-guided therapy or symptom-guided therapy in primary or secondary care. Cohort study: BNP monitored (≥ 6 months’ follow-up and three or more BNP tests and two or more tests per year), BNP tested (≥ 1 tests but not BNP monitored) or never tested. Cost-effectiveness model: BNP-guided therapy in specialist clinics. Main outcome measures: Mortality, hospital admission (all cause and HF related) and adverse events; and quality-adjusted life-years (QALYs) for the cost-effectiveness model. Data sources: Systematic review: Individual participant or aggregate data from eligible RCTs. Cohort study: The Clinical Practice Research Datalink, Hospital Episode Statistics and National Heart Failure Audit (NHFA). Review methods: A systematic literature search (five databases, trial registries, grey literature and reference lists of publications) for published and unpublished RCTs. Results: Five RCTs contributed individual participant data (IPD) and eight RCTs contributed aggregate data (1536 participants were randomised to BNP-guided therapy and 1538 participants were randomised to symptom-guided therapy). For all-cause mortality, the hazard ratio (HR) for BNP-guided therapy was 0.87 [95% confidence interval (CI) 0.73 to 1.04]. Patients who were aged < 75 years or who had heart failure with a reduced ejection fraction (HFrEF) received the most benefit [interactions (p = 0.03): < 75 years vs. ≥ 75 years: HR 0.70 (95% CI 0.53 to 0.92) vs. 1.07 (95% CI 0.84 to 1.37); HFrEF vs. heart failure with a preserved ejection fraction (HFpEF): HR 0.83 (95% CI 0.68 to 1.01) vs. 1.33 (95% CI 0.83 to 2.11)]. In the cohort study, incident HF patients (1 April 2005–31 March 2013) were never tested (n = 13,632), BNP tested (n = 3392) or BNP monitored (n = 71). Median survival was 5 years; all-cause mortality was 141.5 out of 1000 person-years (95% CI 138.5 to 144.6 person-years). All-cause mortality and hospital admission rate were highest in the BNP-monitored group, and median survival among 130,433 NHFA patients (1 January 2007–1 March 2013) was 2.2 years. The admission rate was 1.1 patients per year (interquartile range 0.5–3.5 patients). In the cost-effectiveness model, in patients aged < 75 years with HFrEF or HFpEF, BNP-guided therapy improves median survival (7.98 vs. 6.46 years) with a small QALY gain (5.68 vs. 5.02) but higher lifetime costs (£64,777 vs. £58,139). BNP-guided therapy is cost-effective at a threshold of £20,000 per QALY. Limitations: The limitations of the trial were a lack of IPD for most RCTs and heterogeneous interventions; the inability to identify BNP monitoring confidently, to determine medication doses or to distinguish between HFrEF and HFpEF; the use of a simplified two-state Markov model; a focus on health service costs and a paucity of data on HFpEF patients aged < 75 years and HFrEF patients aged ≥ 75 years. Conclusions: The efficacy of BNP-guided therapy in specialist HF clinics is uncertain. If efficacious, it would be cost-effective for patients aged < 75 years with HFrEF. The evidence reviewed may not apply in the UK because care is delivered differently. Future work: Identify an optimal BNP-monitoring strategy and how to optimise HF management in accordance with guidelines; update the IPD meta-analysis to include the Guiding Evidence Based Therapy Using Biomarker Intensified Treatment (GUIDE-IT) RCT; collect routine long-term outcome data for completed and ongoing RCTs. Trial registration: Current Controlled Trials ISRCTN37248047 and PROSPERO CRD42013005335. Funding: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 40. See the NIHR Journals Library website for further project information. The British Heart Foundation paid for Chris A Rogers’ and Maria Pufulete’s time contributing to the study. Syed Mohiuddin’s time is supported by the NIHR Collaboration for Leadership in Applied Health Research and Care West at University Hospitals Bristol NHS Foundation Trust. Rachel Maishman contributed to the study when she was in receipt of a NIHR Methodology Research Fellowship
Endothelium-derived endothelin-1
One year after the revelation by Dr. Furchgott in 1980 that the endothelium was obligatory for acetylcholine to relax isolated arteries, it was clearly shown that the endothelium could also promote contraction. In 1988, Dr. Yanagisawa’s group identified endothelin-1 (ET-1) as the first endothelium-derived contracting factor. The circulating levels of this short (21-amino acid) peptide were quickly determined in humans, and it was reported that, in most cardiovascular diseases, circulating levels of ET-1 were increased, and ET-1 was then tagged as “a bad guy.” The discovery of two receptor subtypes in 1990, ET(A) and ET(B), permitted optimization of the first dual ET-1 receptor antagonist in 1993 by Dr. Clozel’s team, who entered clinical development with bosentan, which was offered to patients with pulmonary arterial hypertension in 2001. The revelation of Dr. Furchgott opened a Pandora’s box with ET-1 as one of the actors. In this brief review, we will discuss the physiological and pathophysiological role of endothelium-derived ET-1 focusing on the regulation of the vascular tone, and as much as possible in humans. The coronary bed will be used as a running example in this review because it is the most susceptible to endothelial dysfunction, but references to the cerebral and renal circulation will also be made. Many of the cardiovascular complications associated with aging and cardiovascular risk factors are initially attributable, at least in part, to endothelial dysfunction, particularly dysregulation of the vascular function associated with an imbalance in the close interdependence of nitric oxide and ET-1
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