Johns Hopkins University School of Medicine

About: Johns Hopkins University School of Medicine is a healthcare organization based out in Baltimore, Maryland, United States. It is known for research contribution in the topics: Population & Cancer. The organization has 44277 authors who have published 79222 publications receiving 4788882 citations.

Nitric oxide synthase in models of focal ischemia

Abstract: Background and Purpose Cessation of blood flow to the brain, for even a few minutes, sets in motion a potential reversible cascade of events resulting in neuronal cell death. Oxygen free radicals and oxidants appear to play an important role in central nervous system injury after cerebral ischemia and reperfusion. Recently, divergent roles for the newly identified neuronal messenger molecule and oxygen radical, nitric oxide (NO), have been identified in various models of cerebral ischemia. Because of the chemical and physical properties of NO, the numerous physiological activities it mediates, and the lack of specific agents to modulate the activity of the different isoforms of NO synthase (NOS), reports regarding the role of NO in focal cerebral ischemia have been confounding and often conflicting. Recent advances in pharmacology and the development of transgenic knockout mice specific for the different isoforms of NOS have advanced our knowledge and clarified the role of NO in cerebral ischemia. Methods...

Prescription Opioid Analgesics Commonly Unused After Surgery: A Systematic Review.

Abstract: Importance Prescription opioid analgesics play an important role in the treatment of postoperative pain; however, unused opioids may be diverted for nonmedical use and contribute to opioid-related injuries and deaths. Objective To quantify how commonly postoperative prescription opioids are unused, why they remain unused, and what practices are followed regarding their storage and disposal. Evidence Review MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials were searched from database inception to October 18, 2016, for studies describing opioid oversupply for adults after a surgical procedure. The primary outcome—opioid oversupply—was defined as the number of patients with either filled but unused opioid prescriptions or unfilled opioid prescriptions. Two reviewers independently screened studies for inclusion, extracted data, and assessed the study quality. Findings Six eligible studies reported on a total of 810 unique patients (range, 30-250 patients) who underwent 7 different types of surgical procedures. Across the 6 studies, 67% to 92% of patients reported unused opioids. Of all the opioid tablets obtained by surgical patients, 42% to 71% went unused. Most patients stopped or used no opioids owing to adequate pain control, and 16% to 29% of patients reported opioid-induced adverse effects. In 2 studies examining storage safety, 73% to 77% of patients reported that their prescription opioids were not stored in locked containers. All studies reported low rates of anticipated or actual disposal, but no study reported US Food and Drug Administration–recommended disposal methods in more than 9% of patients. Conclusions and Relevance Postoperative prescription opioids often go unused, unlocked, and undisposed, suggesting an important reservoir of opioids contributing to nonmedical use of these products, which could cause injuries or even deaths.

Primary structure and functional expression of a cyclic nucleotide-activated channel from olfactory neurons.

Abstract: ODORANT signal transduction occurs in the specialized cilia of the olfactory sensory neurons. Considerable biochemical evidence now indicates that this process could be mediated by a G protein-coupled cascade using cyclic AMP as an intracellular second messenger1. A stimulatory G protein α subunit is expressed at high levels in olfactory neurons and is specifically enriched in the cilia2, as is a novel form of adenylyl cyclase3. This implies that the olfactory transduction cascade might involve unique molecular components. Electrophysiological studies have identified a cyclic nucleotide-activated ion channel in olfactory cilia4. These observa-tions provide evidence for a model in which odorants increase intracellular cAMP concentration, which in turn activates this channel and depolarizes the sensory neuron. An analogous cascade regulating a cGMP-gated channel mediates visual transduction in photoreceptor cells (see refs 5,6 for review). The formal similarities between olfactory and visual transduction suggest that the two systems might use homologous channels. Here we report the molecular cloning, functional expression and characterization of a channel that is likely to mediate olfactory transduction.