Articles: human.
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Eicosanoids can have either proinflammatory effects or anti-inflammatory effects. Tobin and colleagues use a forward genetic screen in zebrafish to identify a key eicosanoid enzyme, leukotriene A(4) hydrolase (LTA(4)H), that controls susceptibility to mycobacterial infection. They also demonstrate that polymorphisms in LTA(4)H are associated with susceptibility to mycobacteria in humans.
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The present experiment examined the effects of varying stimulus disparity and relative punisher frequencies on signal detection by humans. Participants were placed into one of two groups. Group 3 participants were presented with 1:3 and 3:1 punisher frequency ratios, while Group 11 participants were presented with 1:11 and 11:1 punisher frequency ratios. ⋯ For both groups, estimates of discriminability increased systematically across the three disparity levels and were unaffected by the punisher ratios. Likewise, estimates of response bias and sensitivity to the punisher ratios were unaffected by changes in discriminability, supporting the assumption of parameter invariance in the Davison and Tustin (1978) model of signal detection. Overall, the present experiment found no relation between stimulus control and punisher control, and provided further evidence for similar but opposite effects of punishers to reinforcers in signal-detection procedures.
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Laryngeal mask airways (LMAs) are often used as airway rescue devices where laryngoscopy is difficult. The LMA does not protect the airway and is preferably replaced with a cuffed endotracheal tube. There are reports of cases where an Eschmann tracheal tube introducer (ETTI) was successfully used to bridge between a standard LMA and an endotracheal tube. This project was designed to determine whether an Eschmann stylet can reliably be passed through an LMA into the trachea as a means of rescue intubation. ⋯ While not a primary difficult airway option, the use of a ETTI as a bridge device between LMA and endotracheal tube was successful about 50% of the time.
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Ont Health Technol Assess Ser · Jan 2010
Stress echocardiography with contrast for the diagnosis of coronary artery disease: an evidence-based analysis.
In July 2009, the Medical Advisory Secretariat (MAS) began work on Non-Invasive Cardiac Imaging Technologies for the Diagnosis of Coronary Artery Disease (CAD), an evidence-based review of the literature surrounding different cardiac imaging modalities to ensure that appropriate technologies are accessed by patients suspected of having CAD. This project came about when the Health Services Branch at the Ministry of Health and Long-Term Care asked MAS to provide an evidentiary platform on effectiveness and cost-effectiveness of non-invasive cardiac imaging modalities.After an initial review of the strategy and consultation with experts, MAS identified five key non-invasive cardiac imaging technologies for the diagnosis of CAD. Evidence-based analyses have been prepared for each of these five imaging modalities: cardiac magnetic resonance imaging, single photon emission computed tomography, 64-slice computed tomographic angiography, stress echocardiography, and stress echocardiography with contrast. For each technology, an economic analysis was also completed (where appropriate). A summary decision analytic model was then developed to encapsulate the data from each of these reports (available on the OHTAC and MAS website).The Non-Invasive Cardiac Imaging Technologies for the Diagnosis of Coronary Artery Disease series is made up of the following reports, which can be publicly accessed at the MAS website at: www.health.gov.on.ca/mas or at www.health.gov.on.ca/english/providers/program/mas/mas_about.htmlSINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY FOR THE DIAGNOSIS OF CORONARY ARTERY DISEASE: An Evidence-Based AnalysisSTRESS ECHOCARDIOGRAPHY FOR THE DIAGNOSIS OF CORONARY ARTERY DISEASE: An Evidence-Based AnalysisSTRESS ECHOCARDIOGRAPHY WITH CONTRAST FOR THE DIAGNOSIS OF CORONARY ARTERY DISEASE: An Evidence-Based Analysis64-Slice Computed Tomographic Angiography for the Diagnosis of Coronary Artery Disease: An Evidence-Based AnalysisCARDIAC MAGNETIC RESONANCE IMAGING FOR THE DIAGNOSIS OF CORONARY ARTERY DISEASE: An Evidence-Based AnalysisPease note that two related evidence-based analyses of non-invasive cardiac imaging technologies for the assessment of myocardial viability are also available on the MAS website:POSITRON EMISSION TOMOGRAPHY FOR THE ASSESSMENT OF MYOCARDIAL VIABILITY: An Evidence-Based AnalysisMAGNETIC RESONANCE IMAGING FOR THE ASSESSMENT OF MYOCARDIAL VIABILITY: an Evidence-Based AnalysisThe Toronto Health Economics and Technology Assessment Collaborative has also produced an associated economic report entitled:The Relative Cost-effectiveness of Five Non-invasive Cardiac Imaging Technologies for Diagnosing Coronary Artery Disease in Ontario [Internet]. Available from: http://theta.utoronto.ca/reports/?id=7 OBJECTIVE: The objective of this report is to compare echocardiography (ECHO) performed with microsphere contrast agents (contrast echocardiography) to ECHO performed without contrast and to single photon emission computed tomography (SPECT). CONTRAST ECHO: Contrast agents for ECHO have been available since the technology was first introduced in the 1990s. Composed of tiny 'microbubbles' of an inert gas encapsulated within a lipid, protein, or polymer coat, these agents act to scatter incident ultrasound waves at the gas/liquid interface to increase the strength of a returning ECHO signal. When injected into a patient's arm, they are transported throughout even the smallest capillaries to greatly enhance the blood pool signal, which would otherwise appear black on conventional two dimensional ECHO. The enhanced signal then helps cardiologists to determine what parts of the patient's heart muscle are poorly perfused. The first commercially available microsphere contrast agent was Albunex, which received approval by the Food and Drug Administration in the United States in 1994. This original microsphere agent was limited by its rapid gas volume loss which caused a decline in the ultrasound signal. It worked well in the right chambers of the heart, but dissolved when passing through the pulmonary capillaries and so was unable to provide contrast in the left side. Second generation agents employed different gases that prolonged the life of the microbubbles within the circulation and increased the reproducibility of results. Today, the most common use for contrast ECHO is to enhance the definition of the left ventricular (LV) endocardial border for cases of LV opacification. The aim of contrast ECHO is to provide better quantification of LV volume and assessment of LV wall motion than ECHO alone. The newest area of development in the research of contrast ECHO is myocardial perfusion assessment, also known as myocardial contrast ECHO. Theoretically, since myocardial ischemia and infarction affect both perfusion and contractility (wall motion), contrast ECHO could be an ideal non-invasive imaging test as it could assess both perfusion and contractility, simultaneously and in real time. Notably, critically ill patients on ventilators and those with lung problems are more likely to generate poor or 'suboptimal' echocardiograms than other patients, as are obese patients and those who've undergone recent chest operations. Contrast agents can potentially be used in 10% to 15% of all studies and in approximately 33% of stress tests due to from such suboptimal echocardiograms. Stress can be induced either pharmaceutically (e.g., through dobutamine, dipyrimidamole, adenosine) or with exercise. Generally, contrast agents are used more in pharmaceutical stress echocardiograms than in exercise stress echocardiograms. EVIDENCE-BASED ANALYSIS: This MAS analysis sought to address the following research questions: Is contrast ECHO more effective than 99-technetium SPECT in terms its ability to detect CAD?What is the effectiveness of contrast ECHO in assessing patients with suboptimal echocardiograms?Is contrast ECHO safe compared to other cardiac imaging modalities?Is contrast ECHO cost-effective compared to other cardiac imaging modalities? ⋯ Twenty-three observational studies were identified that assessed the diagnostic accuracy of contrast ECHO for the diagnosis of CAD. All of these studies used stress ECHO with contrast. In addition, nine retrospective chart reviews were identified, which assessed the safety of contrast ECHO at rest or stress. Based on the results of these studies the following conclusions were made: Stress ECHO with contrast has a higher diagnostic accuracy in the diagnosis of CAD than stress ECHO (without contrast).Stress ECHO with contrast seems to have a similar diagnostic accuracy to 99 technetium SPECT.The addition of contrast to ECHO in patients with suboptimal ECHO results significantly improves interpretability of the results.There is not a statistically significantly higher mortality rate in patients who receive contrast compared to those who do not.
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Ont Health Technol Assess Ser · Jan 2010
Kidney and liver organ transplantation in persons with human immunodeficiency virus: An Evidence-Based Analysis.
The objective of this analysis is to determine the effectiveness of solid organ transplantation in persons with end stage organ failure (ESOF) and human immunodeficiency virus (HIV+) ⋯ No direct evidence comparing an HIV+ cohort undergoing transplantation with the same not undergoing transplantation (wait list) was found in the literature search. The results of this review are reported for the following comparison cohorts undergoing transplantation: I) KIDNEY TRANSPLANTATION: HIV+ cohort compared with HIV- cohortII) LIVER TRANSPLANTATION: HIV+ cohort compared with HIV- negative cohortIII) LIVER TRANSPLANTATION: HIV+ HCV+ (co-infected) cohort compared with HCV+ (mono-infected) cohort KIDNEY TRANSPLANTATION: HIV+ VS. HIV#ENTITYSTARTX02212; Based on a pooled HIV+ cohort sample size of 285 patients across four studies, the risk of death after kidney transplantation in an HIV+ cohort does not differ to that of an HIV- cohort [hazard ratio (HR): 0.90; 95% CI: 0.36, 2.23]. The quality of evidence supporting this outcome is very low. Death censored graft survival was reported in one study with an HIV+ cohort sample size of 100, and was statistically significantly different (p=.03) to that in the HIV- cohort (n=36,492). However, the quality of evidence supporting this outcome was determined to be very low. There was also uncertainty in the rate of return to dialysis after kidney transplantation in both the HIV+ and HIV- groups and the effect, if any, this may have on patient survival. Because of the very low quality evidence rating, the effect of kidney transplantation on HIV-disease progression is uncertain. The rate of acute graft rejection was determined using the data from one study. There was a nonsignificant difference between the HIV+ and HIV- cohorts (OR 0.13; 95% CI: 0.01, 2.64), although again, because of very low quality evidence there is uncertainty in this estimate of effect. LIVER TRANSPLANTATION: HIV+ VS. HIV#ENTITYSTARTX02212; Based on a combined HIV+ cohort sample size of 198 patient across five studies, the risk of death after liver transplantation in an HIV+ cohort (with at least 50% of the cohort co-infected with HCV+) is statistically significantly 64% greater compared with an HIV- cohort (HR: 1.64; 95% CI: 1.32, 2.02). The quality of evidence supporting this outcome is very low. Death censored graft survival was reported for an HIV+ cohort in one study (n=11) however the DCGS rate of the contemporaneous control HIV- cohort was not reported. Because of sparse data the quality of evidence supporting this outcome is very low indicating death censored graft survival is uncertain. Both the CD4+ T-cell count and HIV viral load appear controlled post transplant with an incidence of opportunistic infection of 20.5%. However, the quality of this evidence for these outcomes is very low indicating uncertainty in these effects. Similarly, because of very low quality evidence there is uncertainty in the rate of acute graft rejection among both the HIV+ and HIV- groups LIVER TRANSPLANTATION: HIV+/HCV+ VS. HCV+ Based on a combined HIV+/HCV+ cohort sample size of 156 from seven studies, the risk of death after liver transplantation is significantly greater (2.8 fold) in a co-infected cohort compared with an HCV+ mono-infected cohort (HR: 2.81; 95% CI: 1.47, 5.37). The quality of evidence supporting this outcome is very low. Death censored graft survival evidence was not available. Regarding disease progression, based on a combined sample size of 71 persons in the co-infected cohort, the CD4+ T-cell count and HIV viral load appear controlled post transplant; however, again the quality of evidence supporting this outcome is very low. The rate of opportunistic infection in the co-infected cohort was 7.2%. The quality of evidence supporting this estimate is very low, indicating uncertainty in these estimates of effect. Based on a combined HIV+/HCV+ cohort (n=57) the rate of acute graft rejection does not differ to that of an HCV+ mono-infected cohort (OR: 0.88; 95% CI: 0.44, 1.76). Also based on a combined HIV+/HCV+ cohort (n=83), the rate of HCV+ recurrence does not differ to that of an HCV+ mono-infected cohort (OR: 0.66; 95% CI: 0.27, 1.59). In both cases, the quality of the supporting evidence was very low. Overall, because of very low quality evidence there is uncertainty in the effect of kidney or liver transplantation in HIV+ persons with end stage organ failure compared with those not infected with HIV. Examining the economics of this issue, the cost of kidney and liver transplants in an HIV+ patient population are, on average, 56K and 147K per case, based on both Canadian and American experiences.