Clinical implications of increased lung uptake of thallium-201 during exercise scintigraphy 2 weeks after myocardial infarction

To determine the prevalence and clinical significance of increased lung thallium-201 uptake during submaximal exercise myocardial scintigraphy performed 2 weeks after acute myocardial infarction, 61 patients underwent submaximal exercise testing (target heart rate, 120 beats/min), multigated blood pool imaging at rest and coronary angiography before hospital discharge. Thallium lung uptake on the initial anterior projection image was graded qualitatively by comparing the intensity of thallium-201 activity in the lungs with that in the mediastinum. In 39 patients (64 percent), it was normal (equal to mediastinal activity) and in 22 (36 percent), it was increased (greater than mediastinal activity). Compared with patients with normal lung uptake, those with increased uptake had a greater prevalence of prior infarction (13 versus 36 percent, probability [p] < 0.05), less global cardiac reserve as assessed by the four level New York Heart Association classification (p < 0.05), more advanced Killip class in the coronary care unit (p < 0.05), a higher Norris coronary prognostic index (2.6 ± 1.9 versus 4.6 ± 2.3 [mean ± standard deviation], p <0.01), failure to achieve the target heart rate because of dyspnea, fatigue or angina (36 versus 86 percent, p < 0.01), a greater prevalence of exercise-induced S-T segment depression (18 versus 45 percent, p < 0.05), a greater number of anterior thallium-201 myocardlal defects (p < 0.05); a lower radionuclide ejection fraction at rest (50.4 ± 6.1 versus 39.6 ± 9.3 percent, p < 0.01) and a greater number of asynergic left ventricular segments (p < 0.05).Thus, the occurrence of increased lung thallium-201 uptake during submaximal exercise scintigraphy in the early postinfarction period is frequent and appears to be a marker of severe and functionally more important coronary artery disease associated with left ventricular dysfunction.     

Pragmatic Trials in Long-Term Care: Implementation and Dissemination Challenges and Opportunities

Randomized controlled trials are considered the most rigorous research design in efficacy and effectiveness research; however, such trials present numerous challenges that limit their applicability in real-world settings. As a consequence, pragmatic trials are increasingly viewed as a research design that overcomes some of these barriers with the potential to produce findings that are more reproducible. Although pragmatic methodology in long-term care is receiving increasing attention as an approach to improve successful dissemination and implementation, pragmatic trials present complexities of their own. To address these complexities and related issues, experts with experience conducting pragmatic trials, developing nursing home policy, participating in advocacy efforts, and providing clinical care in long-term care settings participated in a virtual consensus conference funded by the National Institute on Aging in Spring 2021. Participants identified 4 cross-cutting principles key to dissemination and implementation of pragmatic trial interventions: (1) stakeholder engagement, (2) diversity and inclusion, (3) organizational strain and readiness, and (4) learn from adaptations. Participants emphasized that implementation processes must be grounded in the perspectives of the people who will ultimately be responsible for implementing the intervention once it is proven to be effective. In addition, messaging must speak to long-term care staff and all others who have a stake in its outcomes. Although our understanding of dissemination and implementation strategies remains underdeveloped, this article is designed to guide long-term care researchers and community providers who are increasingly aware of the need for pragmatism in disseminating and implementing evidence-based care interventions.     

Altered controls of proliferation in proximal small intestine of the senescent rat.

The proximal small intestine responds to starvation by rapidly reducing crypt cell proliferation rate and villus cellularity and to resumption of food intake (refeeding) by abruptly increasing proliferation and the number of villus epithelial cells. We show that villus cellularity responds to starvation and refeeding similarly in young and aging animals. However, as compared to young animals, senescent rats showed increased basal DNA synthetic activity, starvation resulted in a smaller decrease in DNA labeling of crypt cells, and refeeding produced an abrupt broadening of the proliferative zone in older animals without concomitant increased numbers of villus cells. Such altered crypt proliferative responses resemble precancerous changes seen in the colon and the aberrant proliferation found in both small and large intestine after administration of the carcinogen dimethylhydrazine.