The main objectives of the current study were to obtain the complete cDNA sequence of an opioid-like receptor from an amphibian, the roughskin newt, Taricha granulosa, and investigate the receptor's tissue distribution and regulation following chronic exposure to the glucocorticoid corticosterone (CORT). Degenerate primers designed in highly conserved regions of characterized opioid receptors were used to amplify opioid-like receptor fragments from a newt brain cDNA library. Receptor fragments with high sequence identity to the orphanin opioid receptor type, also termed the 'opioid receptor-like' (ORL1) receptor, were selected for 3' and 5' RACE (rapid amplification of cDNA ends) reactions to obtain the full-length receptor cDNA sequence. By this approach, we obtained a cDNA sequence that putatively encodes a 368 amino acid protein with high sequence identity (57%) to the human ORL1 receptor. Therefore, hereafter we refer to this receptor as the newt ORL1-like (nORL) receptor. The nORL receptor also has identity with the mammalian kappa (K) opioid receptor at a number of residues that may enable it to recognize both ORL1- and K- receptor selective ligands. The tissue distribution of the nORL receptor was determined by reverse-transcriptase polymerase chain reaction (PCR). RNA from a variety of tissues was reverse-transcribed into cDNA using an oligo-dT primer, and the resultant cDNA was used as template in PCR reactions with nORL receptor-specific primers. Appropriately sized amplicons were produced in reactions with cDNA template originating from newt brain, spinal cord, and lungs. No amplification occurred in reactions with template cDNA from newt spleen, small intestine, heart, liver, sperm duct, bladder, or kidney. The regulation of the nORL receptor following chronic exposure to the glucocorticoid corticosterone was investigated using real-time PCR. Animals were exposed continuously to CORT for 10 days using surgically implanted Silastic capsules packed with CORT powder. Control animals received empty Silastic capsules, or no treatment. The relative quantitation of the nORL receptor messenger RNA (mRNA) was achieved by real-time PCR, and mRNA levels for the hormone-treated animals were compared to those of the controls. The same samples were used for the relative quantitation of intracellular glucocorticoid receptor (iGR) mRNA. There was no change in the expression of mRNA for the nORL receptor or the iGR following chronic exposure to CORT as compared to the controls. In conclusion, this study provides evidence for an opioid-like receptor in the roughskin newt that has high sequence identity to the mammalian ORL1 opioid receptor. To the best of our knowledge, this is the first complete opioid receptor cDNA sequence obtained for an amphibian. The nORL receptor appears to principally function in central nervous system (CNS) processes in the newt, as evidenced by its primary localization to brain and spinal cord. The role of the nORL receptor in the periphery may be limited to a function in the lungs, and awaits further investigation. The current study was also the first to investigate the effects of a stress hormone on the regulation of an opioid receptor in an amphibian. Our results indicate that chronic exposure to the stress hormone corticosterone does not impact the levels of nORL receptor or intracellular glucocorticoid receptor mRNA in the newt spinal cord. / Graduation date: 2003

Abstract Physicians in the emergency department (ED) are facing a number of unique challenges in the currently changing healthcare and economic climates. Dramatic increases in ED patient volumes have been noted nationwide with visits related to prescription opioid abuse and misuse alone having increased by 111% between 2004 and 2008. Ironically, several challenges ED physicians are facing arise from regulatory and economic initiatives which were originally designed for the protection of patients. Regulatory requirements to address pain as the fifth vital sign, along with entities utilizing patient satisfaction based reimbursement, have inadvertently created an environment conducive to exploitation by the prescription opioid abuser. A literature review revealed an informational gap with regard to the impact economic and regulatory factors exert on the management of patients, exhibiting drug seeking behavior, by ED physicians. The lack of available information is the basis for this original research. A descriptive, cross-sectional, non-experimental study was conducted over a two month period (October - November, 2013) to elicit opinions of ED physicians regarding the management of opioid seeking patients. Respondents were asked to include opinions on factors perceived to impact treatment of this patient population. Of the ED physicians surveyed, 71% reported a perceived pressure to prescribe opioids to avoid administrative and regulatory criticism and 98% perceive patient satisfaction scores as being too highly emphasized by reimbursement entities as a means of evaluating healthcare quality. Rising patient volumes and changes in the healthcare climate were also cited as factors impacting management practices when treating patients exhibiting drug seeking behavior. Emergency department physicians have a unique role in providing unrestricted access of care for the public. This role, in conjunction with the aforementioned concerns, has served to create an environment conducive to the potentiation of prescription opioid misuse and abuse.

The economic burden of prescription opioid abuse is believed to be substantial, however it is not known whether total and per-event hospital (ED and inpatient) costs associated with opioid abuse or misuse differ by insurance status. We also wanted identify predictors of charges. We used the 2006, 2007, and 2008 files of the Healthcare Cost and Utilization Project's Nationwide Emergency Departments Sample (HCUP-NEDS) to identify events and charges assigned opioid abuse, dependence, or poisoning ICD-9-CM diagnosis codes (304.0X, 304.7X, 305.5X, 965.00, 965.02, 965.09). Using methods to account for the sampling design of the NEDS, we estimated national total and mean charges -- overall and by insurance status (Medicare, Medicaid, private insurance, or self-payment). Charges were adjusted using the 2010 Medical Consumer Price Hospital Services index. We used a log-linked gamma regression model to assess potential predictors of charges. The number of opioid abuse-related events was 515,896; 506,837; and 564,559 for 2006, 2007, and 2008, respectively. Approximately 55% visits in each year resulted in inpatient admissions. Total charges billed for opioid abuse-related events were US$9.8; 9.6; and 9.5 billion for 2006, 2007, and 2008, respectively. Medicaid patients had the highest charges in each years followed by Medicare patients. Approximately 93% of total charges were due to subsequent inpatient admission. Overall unadjusted mean charges were $20,651; $20,373; and $18,384 for 2006, 2007, and 2008, respectively. Compared to events paid for by private insurance, Medicaid-covered events had significantly higher mean charges, and self-paid events had significantly lower charges (p < 0.001 for each year). Inpatient admissions resulted in significantly higher mean charges compared to treat-and-release ED visits (p < 0.001 for each year). We found similar results after adjusting for clinical and demographic factors. Age, number of diagnoses, inpatient admission, presence of cardiac tissue disorders, respiratory infections or failure, gastrointestinal hemorrhage, and acute pancreatitis were significantly positively associated with total charges billed (p < 0.001 for all). This study helps in determining differences in hospital costs of opioid abusers by insurance status and in identifying potential predictors of such costs, resulting in better understanding the economic burden of opioid abuse on the healthcare system. / text

published_or_final_version / Zoology / Master / Master of Philosophy

published_or_final_version / Biochemistry / Master / Master of Philosophy

published_or_final_version / Physiology / Doctoral / Doctor of Philosophy

The use of prescription opioids for chronic non-cancer pain is complex. Opioids have the potential to alleviate discomfort and increase ones overall ability to function but, long term use also has potential physical and psychological impacts. The purpose of this study was to explore the lived experience of adults who use prescription opioids to manage chronic non-cancer pain. Nine participants were recruited and interviewed. Participants were asked to describe how using prescription opioids had affected their lives. Interviews were recorded, transcribed and analyzed thematically using Interpretative phenomenological analysis (IPA). Eight themes emerged from the data: the process of decision making, physical effects of using opioids, social consequences of using opioids, Guilt, fears, ambivalence, self-protection, and acceptance. Using opioids made pain more manageable and improved function for most of the participants. Nevertheless, using opioids was also associated with stigma, guilt, fears and ambivalence about their future as persons with chronic pain.

When administered systemically, benzodiazepine receptor agonists have been shown to increase food intake in a number of species. Conversely, benzodiazepine receptor inverse agonists bring about reliable decreases in feeding. The aim of the experiments reported in this thesis was to investigate the brain and behavioural mechanisms involved in the effects of benzodiazepines on ingestion. The effect on food intake of microinjection of the benzodiazepine receptor agonist midazolam into the brainstem of the rat was investigated. A reliable hyperphagic response was elicited following injection of midazolam into both the IVth ventricle and the parabrachial nucleus (PEN). This increase in intake was reversed by pretreatment with the selective benzodiazepine receptor antagonist flumazenil. These results suggest that benzodiazepine receptors located in the brainstem, specifically in the PEN, may be responsible for the effects of benzodiazepines on ingestion. In further experiments, a microstructural approach was adopted which involved analyzing the effects of benzodiazepine ligands on the detailed pattern of licking for both a carbohydrate and a fat in the rat. The effects of midazolam were similar to the effects of increasing concentration. The effects of the benzodiazepine receptor inverse agonist Ro 15-4513 were similar to the effects of decreasing concentration. These results suggest that benzodiazepines influence ingestive behaviour by modulating palatability. The proposal that benzodiazepines may interact with opioids to influence feeding behaviour was examined in Chapters 7 and 8. Although the effects of the opioid agonist morphine and the opioid antagonist naloxone on licking behaviour were not the same as the effects of benzodiazepine ligands, naloxone blocked the effects of midazolam. These results suggest that the effects of benzodiazepine on palatability may depend on release of endogenous opioid peptides. This work has implications for understanding the neural control of ingestive behaviour and may help in developing new therapies for clinical disorders such as anorexia and bulimia.

Thesis (Ph. D.)--University of Hawaii at Manoa, 1991. / Includes bibliographical references (leaves 41-43, 244-250) / Microfiche. / xiii, 374 leaves, bound ill. 29 cm

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 117-154).