University of Louisville

About: University of Louisville is a education organization based out in Louisville, Kentucky, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 24600 authors who have published 49248 publications receiving 1573346 citations. The organization is also known as: UofL.

Spinal cord stimulation for patients with failed back surgery syndrome: a systematic review

Abstract: Background: Failed back surgery syndrome is common in the United States. Management of post lumbar surgery syndrome with multiple modalities includes interventional techniques, resulting in moderate improvement, leaving a proportion of patients in intractable pain. The systematic reviews of long-term benefits and risks of spinal cord stimulation (SCS) for patients with failed back surgery syndrome showed limited to moderate evidence and cost effectiveness. However, with the exponential increase in surgery in the United States, spinal cord implants are also increasing. Thus, the discussion continues with claims of lack of evidence on one hand and escalating increases in utilization on the other hand. Study Design: A systematic review of SCS in patients with failed back surgery syndrome. Objectives: This systematic review is undertaken to examine the evidence from randomized controlled trials (RCTs) and observational studies to evaluate the effectiveness of SCS in post lumbar surgery syndrome and to demonstrate clinical and cost effectiveness. Methods: Review of the literature was performed according to the Cochrane Musculoskeletal Review Group Criteria as utilized for interventional techniques for randomized trials and the Agency for Healthcare Research and Quality (AHRQ) criteria for observational studies. The 5 levels of evidence were classified as Level I, II, or III with 3 subcategories in Level II based on the quality of evidence developed by the U.S. Preventive Services Task Force (USPSTF).

Nitric Oxide Donors Induce Late Preconditioning Against Myocardial Stunning and Infarction in Conscious Rabbits via an Antioxidant-Sensitive Mechanism

Abstract: —The goal of this study was to test the hypothesis that the cardioprotective effects of the late phase of ischemic preconditioning (PC) can be mimicked by treatment with NO donors. In phase I (studies of myocardial stunning), conscious rabbits underwent a sequence of six 4-minute coronary occlusion/4-minute reperfusion cycles for 3 consecutive days (days 1, 2, and 3). In group I (controls, n=6), the total deficit of systolic wall thickening (WTh) after the sixth reperfusion was reduced by 54% on days 2 and 3 compared with day 1 ( P <0.05), indicating a late PC effect against myocardial stunning. When rabbits were given the NO donors diethylenetriamine/NO (DETA/NO, 0.1 mg/kg IV, 4 times [group II, n=5]) or S -nitroso- N -acetylpenicillamine (SNAP, 2.5 μg · kg−1 · min−1 IV for 75 minutes [group III, n=5]) 24 hours before the first sequence of occlusion/reperfusion cycles, the deficit of WTh on day 1 was 60% (group II) and 54% (group III) less than that observed in controls ( P <0.05 for both). In both groups II and III, there was no further improvement in the deficit of WTh on days 2 and 3 compared with day 1. The protective effect of DETA/NO was completely abrogated when this agent was given in conjunction with the ONOO− and ·OH scavenger mercaptopropionyl glycine (MPG) (group IV, n=5). In phase II (studies of myocardial infarction), conscious rabbits underwent a 30-minute coronary occlusion followed by 3 days of reperfusion. When rabbits were preconditioned 24 hours earlier with six 4-minute occlusion/4-minute reperfusion cycles, infarct size was reduced by 43% (33.2±2.7% versus 58.3±4.1% of the region at risk in controls, P <0.05), indicating a late PC effect against myocardial infarction. When rabbits were pretreated with DETA/NO (group VII, n=8) or SNAP (group IX, n=7) 24 hours before the 30-minute occlusion, infarct size was reduced by a similar degree (29.3±3.6% and 32.0±3.3% of the region at risk, respectively; P <0.05 versus controls). The degree of protection could not be increased by doubling the dose of DETA/NO (group VIII, n=5). Coadministration of MPG completely abrogated the infarct-sparing action of DETA/NO (group X, n=7). Taken together, these results demonstrate that in conscious rabbits the administration of 2 structurally unrelated NO donors induces protection 24 hours later against both reversible (stunning) and irreversible (infarction) ischemia/reperfusion injury and that the magnitude of this protection is indistinguishable from that observed during the late phase of ischemic PC. The fact that the late phase of ischemic PC can be mimicked by NO donors provides direct evidence that NO in itself is sufficient to elicit this cardioprotective mechanism. The fact that NO donor–induced late PC was abrogated by MPG indicates that the mechanism whereby NO induces this phenomenon involves the generation of oxidant species, possibly ONOO– and/or ·OH. Since a relatively brief treatment with hemodynamically inactive doses of NO donors can induce long-lasting protective effects, these agents could be useful for preconditioning the heart in patients.

Scale-dependent determinants and consequences of benthic algal heterogeneity

Abstract: The objectives of this paper were to introduce frameworks for predicting the determinants and consequences of the great heterogeneity in benthic algal assemblages. A hierarchical framework of environmental factors affecting benthic algal spatial heterogeneity is presented with the ultimate determinants (climate, geology, land use, and biogeography) that are important constraints on benthic algal assemblage structure at large spatial scales. These ultimate determinants constrain expression of intermediate and proximate determinants of benthic algal function and structure. A similar framework for temporal heterogeneity distinguishes how assemblages respond to short-term and long-term environmental changes, referred to as disturbances and stresses, respectively. Assemblages recover from punctuated (short-term) environmental change (disturbance) by immigration and reproduction of both persistent and recolonizing species. Assemblages adapt to permanent (longterm) environmental change (stress) by changing speci...

The physiologic response and associated clinical benefits from provision of early enteral nutrition.

Abstract: Provision of enteral nutrition (EN) to critically ill patients early upon admission to the intensive care unit exerts a beneficial physiologic effect that downregulates systemic immune responses, reduces oxidative stress, and improves patient outcome. Adding specific pharmaconutrient agents to EN in certain patient populations has a synergistic effect, magnifying the degree of this favorable physiologic response. In contrast, failure to provide enteral nutrients creates a physiologic profile that exacerbates oxidative stress and increases the systemic inflammatory response syndrome. Unfortunately, parenteral nutrition (PN) in the form and manner currently provided in North America does not appear to mimic the same physiologic response seen with EN. In the future, use of alternative fuel sources, steps to promote better tolerance of EN, and innovative strategies for delivery of both EN and PN may serve to further enhance the physiologic effect of nutrition therapy and to achieve even greater improvement in patient outcome.