Each year, 55 000 organ transplants are performed worldwide. Cumulatively, the number of living organ recipients is now estimated to be over 300 000. Most of these transplant recipients will remain on immunosuppressive drugs for the remainder of their lives to prevent rejection episodes. Controlled doses of these drugs are required to prevent over-medication, which may leave the patient susceptible to opportunistic infection and drug toxicity effects, or under-dosing, which may lead to shortened graft survival because of rejection episodes. This paper describes the result of a multicenter study conducted at the Universities of Pittsburgh, Alabama and Maryland to evaluate an in vitro assay (CylexTM Immune Cell Function Assay) for the measurement of global immune response in transplant patients receiving immunosuppressive therapy. The assay uses a whole blood sample to maintain the presence of the drug during incubation. Following overnight incubation of blood with phytohemagglutinin (PHA), CD4 cells are selected using paramagnetic particles coated with a monoclonal antibody to the CD4 epitope. The CD4-positive cells are targeted as major immunosuppressive drugs are designed to specifically inhibit T-cell activation which has been implicated in rejection. The data generated at these three sites were submitted in support of an Food and Drug Association (FDA) application for the use of this assay in the detection of cell-mediated immunity in an immunosuppressed population. The assay was cleared by the FDA on April 2, 2002. This cross-sectional study was designed to establish ranges for reactivity of this bioassay in the assessment of functional immunity for an individual solid organ recipient at any point in time.
The Gompertz function provides estimates of the age and the amount of myopia at stabilization in an ethnically diverse cohort. These findings should provide guidance on the time course of myopia and on decisions regarding the type and timing of interventions.
BackgroundPlacebos are widely used in clinical practice in spite of ethical restrictions. Whether such use is justified depends in part on the relative benefit of placebos compared to ‘active’ treatments. A direct test for differences between placebo and ‘active’ treatment effects has not been conducted.ObjectivesWe aimed to test for differences between treatment and placebo effects within similar trial populations.Data SourcesA Cochrane Review compared placebos with no treatment in three-armed trials (no treatment, placebo, and treatment). We added an analysis of treatment and placebo differences within the same trials.Synthesis MethodsFor continuous outcomes we compared mean differences between placebo and no treatment with mean differences between treatment and placebo. For binary outcomes we compared the risk ratio for treatment benefit (versus placebo) with the risk ratio for placebo benefit (versus no treatment). We conducted several preplanned subgroup analyses: objective versus subjective outcomes, conditions tested in three or more trials, and trials with varying degrees of bias.ResultsIn trials with continuous outcomes (n = 115) we found no difference between treatment and placebo effects (MD = −0.29, 95% CI −0.62 to 0.05, P = 0.10). In trials with binary outcomes (n = 37) treatments were significantly more effective than placebos (RRR = 0.72, 95%CI = 0.61 to 0.86, P = 0.0003). Treatment and placebo effects were not different in 22 out of 28 predefined subgroup analyses. Of the six subgroups with differences treatments were more effective than placebos in five. However when all criteria for reducing bias were ruled out (continuous outcomes) placebos were more effective than treatments (MD = 1.59, 95% CI = 0.40 to 2.77, P = 0.009).Conclusions and ImplicationsPlacebos and treatments often have similar effect sizes. Placebos with comparatively powerful effects can benefit patients either alone or as part of a therapeutic regime, and trials involving such placebos must be adequately blinded.
Our findings highlight the importance of intangible factors such as staff attributes and participants' study commitment in maintaining high retention rates, and the usefulness of surveying both families and staff.
Purpose
To examine the relationship of choroidal thickness with axial length (AL) and myopia in young adult eyes in the ethnically diverse Correction of Myopia Evaluation Trial (COMET) cohort.
Design
Cross-sectional, multi-center, study
Methods
In addition to measures of myopia by cycloplegic autorefraction and AL by A-scan ultrasonography, participants underwent optical coherence tomography imaging of the choroid (RTVue) in both eyes at their last visit (14 years after baseline). Using digital calipers, two independent readers measured choroidal thickness in the right eye (left eye if poor quality; n=37) at seven locations: fovea and 750, 1500, 2250μm nasal (N) and temporal (T) to the fovea.
Results
Choroidal thickness measurements were available from 294/346 (85%) of imaged participants (mean age: 24.3±1.4 years; 44.9% male) with mean myopia of -5.3±2.0D and mean AL of 25.5±1.0mm. Overall, choroidal thickness varied by location (p<0.0001) and was thickest at the fovea (273.8±70.9 μm) and thinnest nasally (N2250,191.5±69.3 μm). Multivariable analyses showed significantly thinner choroids in eyes with more myopia and longer AL at all locations except T2250 (p≤0.001) and presence of peri-papillary crescent at all locations except T1500 and T2250 (p≤0.0001). Choroidal thickness varied by ethnicity at N2250 (p<0.0001), with Asians having the thinnest and African Americans the thickest choroids.
Conclusion
Choroids are thinner in longer, more myopic young adult eyes. The thinning was most prominent nasally and in eyes with a crescent. In the furthest nasal location, ethnicity was associated with choroidal thickness. The findings suggest that choroidal thickness should be evaluated, especially in the nasal regions where myopic degenerations are most commonly seen clinically.
Strong psychometric properties, including MMI correlation, of CMSENS warrant investigation into future widespread implementation as a preinterview noncognitive screening test.
We review a novel strategy for tolerance induction developed in rhesus macaques and termed STEALTH. We summarize the evolution of the STEALTH model, the results of successful trials in inducing long-term, stable transplant tolerance in rhesus kidney and diabetic islet recipients and discuss information related to the mechanism by which durable tolerance is induced. STEALTH tolerance is induced by a 3-day treatment course of CD3epsilon immunotoxin (IT) combined with a 14-day treatment with deoxyspergualin (DSG). IT causes profound depletion of sessile lymph node T cells as well as the more accessible circulating T cells. DSG, an inhibitor of HSC 70-mediated NF-kappaB nuclear translocation, arrests maturation of myeloid dendritic cells, blocks production of proinflammatory cytokines induced by IT administration, and promotes systemic production of Th2 type cytokines that persist indefinitely. Such Th2 cytokine deviation has not been reported in NHP transplant recipients. These studies provide proof of principle in a preclinical model that prevention of both acute and chronic allograft rejection, for at least 2.2-4.9 years of follow-up, can be achieved in NHP in the absence of chronic immunosuppressive drugs or other interventions. This strategy for inducing NHP tolerance is discussed in relation to current tolerance paradigms.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.