118 results on '"Smith FL"'
Search Results
2. Engaging with Transformative Paradigms in Mental Health
- Author
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Whitaker, L, Smith, FL, Brasier, C, Petrakis, M, Brophy, L, Whitaker, L, Smith, FL, Brasier, C, Petrakis, M, and Brophy, L
- Abstract
When graduates of Australian social work courses embark on a career in mental health, the systems they enter are complex, fragmented and evolving. Emerging practitioners will commonly be confronted by the loneliness, social exclusion, poverty and prejudice experienced by people living with mental distress; however, social work practice may not be focused on these factors. Instead, in accordance with the dominant biomedical perspective, symptom and risk management may predominate. Frustration with the limitations evident in this approach has seen the United Nations call for the transformation of mental health service delivery. Recognising paradigmatic influences on mental health social work may lead to a more considered enactment of person centred, recovery and rights-based approaches. This paper compares and contrasts influences of neo-liberalism, critical theory, human rights and post-structuralism on mental health social work practice. In preparing social work practitioners to recognise the influence of, and work more creatively with, intersecting paradigms, social work educators strive to foster a transformative approach to mental health practice that straddles discourses.
- Published
- 2021
3. Malware and Disease: Lessons from Cyber Intelligence for Public Health Surveillance
- Author
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Smith Fl rd
- Subjects
medicine.medical_specialty ,Engineering ,Health (social science) ,Health, Toxicology and Mutagenesis ,0211 other engineering and technologies ,Public Policy ,02 engineering and technology ,Management, Monitoring, Policy and Law ,Computer security ,computer.software_genre ,Security Measures ,03 medical and health sciences ,United States Public Health Service ,Public health surveillance ,medicine ,Electronic Health Records ,Humans ,Public Health Surveillance ,Computer Security ,021110 strategic, defence & security studies ,Government ,Disease surveillance ,030505 public health ,Information Dissemination ,business.industry ,Information sharing ,Public health ,Politics ,Public Health, Environmental and Occupational Health ,Information technology ,Original Articles ,United States ,Emergency Medicine ,Malware ,0305 other medical science ,business ,Cyberspace ,Safety Research ,computer ,Software - Abstract
Malicious software and infectious diseases are similar is several respects, as are the functional requirements for surveillance and intelligence to defend against these threats. Given these similarities, this article compares and contrasts the actors, relationships, and norms at work in cyber intelligence and disease surveillance. Historical analysis reveals that civilian cyber defense is more decentralized, private, and voluntary than public health in the United States. Most of these differences are due to political choices rather than technical necessities. In particular, political resistance to government institutions has shaped cyber intelligence over the past 30 years, which is a troubling sign for attempts to improve disease surveillance through local, state, and federal health departments. Information sharing about malware is also limited, despite information technology being integral to cyberspace. Such limits suggest that automation through electronic health records will not automatically improve public health surveillance. Still, certain aspects of information sharing and analysis for cyber defense are worth emulating or, at the very least, learning from to help detect and manage health threats.
- Published
- 2016
4. Effect of Aggregate Quality on Resistance of Concrete to Abrasion
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Smith, FL, primary
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5. Involvement of PKCα and G-protein-coupled receptor kinase 2 in agonist-selective desensitization of µ-opioid receptors in mature brain neurons
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Bailey, CP, primary, Oldfield, S, additional, Llorente, J, additional, Caunt, CJ, additional, Teschemacher, AG, additional, Roberts, L, additional, McArdle, CA, additional, Smith, FL, additional, Dewey, WL, additional, Kelly, E, additional, and Henderson, G, additional
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- 2009
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6. Involvement of PKC alpha and G-protein-coupled receptor kinase 2 in agonist-selective desensitization of mu-opioid receptors in mature brain neurons.
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Bailey, CP, Oldfield, S, Llorente, J, Caunt, CJ, Teschemacher, AG, Roberts, L, McArdle, CA, Smith, FL, Dewey, WL, Kelly, E, Henderson, G, Bailey, C P, Caunt, C J, Teschemacher, A G, McArdle, C A, Smith, F L, and Dewey, W L
- Subjects
PROTEIN kinase C ,G proteins ,CELL receptors ,DESENSITIZATION (Psychotherapy) ,OPIOID receptors ,BRAIN ,NEURONS ,LABORATORY mice ,RESEARCH ,ANIMAL experimentation ,PROTEIN kinase inhibitors ,AGE distribution ,RESEARCH methodology ,EVALUATION research ,MEDICAL cooperation ,RATS ,COMPARATIVE studies ,TRANSFERASES ,ENKEPHALINS ,RESEARCH funding ,MICE ,PHARMACODYNAMICS - Abstract
Background and Purpose: The ability of an agonist to induce desensitization of the mu-opioid receptor (MOR) depends upon the agonist used. Furthermore, previous data suggest that the intracellular mechanisms underlying desensitization may be agonist-specific. We investigated the mechanisms underlying MOR desensitization, in adult mammalian neurons, caused by morphine (a partial agonist in this system) and DAMGO (a high-efficacy agonist).Experimental Approach: MOR function was measured in locus coeruleus neurons, by using whole-cell patch-clamp electrophysiology, in rat and mouse brain slices (both wild-type and protein kinase C (PKC)alpha knockout mice). Specific isoforms of PKC were inhibited by using inhibitors of the receptors for activated C-kinase (RACK), and in vivo viral-mediated gene-transfer was used to transfect neurons with dominant negative mutants (DNMs) of specific G-protein-coupled receptor kinases (GRKs).Key Results: Morphine-induced desensitization was attenuated by using RACK inhibitors that inhibit PKCalpha, but not by other isoform-specific inhibitors. Further, the PKC component of morphine-induced desensitization was absent in locus coeruleus neurons from PKCalpha knockout mice. The PKC-enhanced morphine-induced desensitization was not affected by over-expression of a GRK2 dominant negative mutant (GRK2 DNM). In contrast, DAMGO-induced MOR desensitization was independent of PKC activity but was reduced by over-expression of the GRK2 DNM but not by that of a GRK6 DNM.Conclusions and Implications: In mature mammalian neurons, different MOR agonists can induce MOR desensitization by different mechanisms, morphine by a PKCalpha-mediated, heterologous mechanism and DAMGO by a GRK-mediated, homologous mechanism. These data represent functional selectivity at the level of receptor desensitization. [ABSTRACT FROM AUTHOR]- Published
- 2009
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7. The effect of chlorpromazine on the behavior of disturbed children
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Smith Fl, Huber Wg, and Lane Gg
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Psychiatry and Mental health ,business.industry ,Chlorpromazine ,Mental Disorders ,Medicine ,Humans ,Infant ,Psychology, Child ,business ,Child ,Clinical psychology ,medicine.drug - Published
- 1958
8. A rare case of extramammary Paget disease in a young HIV-positive man.
- Author
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D'Angelo J and Smith FL
- Abstract
Competing Interests: None disclosed.
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- 2023
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9. B-1 plasma cells require non-cognate CD4 T cell help to generate a unique repertoire of natural IgM.
- Author
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Smith FL, Savage HP, Luo Z, Tipton CM, Lee FE, Apostol AC, Beaudin AE, Lopez DA, Jensen I, Keller S, and Baumgarth N
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- Mice, Animals, B-Lymphocytes, Immunoglobulin M, CD4-Positive T-Lymphocytes, Plasma Cells, B-Lymphocyte Subsets
- Abstract
Evolutionarily conserved, "natural" (n)IgM is broadly reactive to both self and foreign antigens. Its selective deficiency leads to increases in autoimmune diseases and infections. In mice, nIgM is secreted independent of microbial exposure to bone marrow (BM) and spleen B-1 cell-derived plasma cells (B-1PC), generating the majority of nIgM, or by B-1 cells that remain non-terminally differentiated (B-1sec). Thus, it has been assumed that the nIgM repertoire is broadly reflective of the repertoire of body cavity B-1 cells. Studies here reveal, however, that B-1PC generate a distinct, oligoclonal nIgM repertoire, characterized by short CDR3 variable immunoglobulin heavy chain regions, 7-8 amino acids in length, some public, many arising from convergent rearrangements, while specificities previously associated with nIgM were generated by a population of IgM-secreting B-1 (B-1sec). BM, but not spleen B-1PC, or B-1sec also required the presence of TCRαβ CD4 T cells for their development from fetal precursors. Together, the studies identify important previously unknown characteristics of the nIgM pool., (© 2023 Smith et al.)
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- 2023
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10. Antibiotic prophylaxis for full thickness and split thickness skin grafts in Mohs micrographic surgery: A retrospective case series and review of the literature.
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Marous M, Bax M, Smith FL, and Brown M
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- Antibiotic Prophylaxis, Humans, Retrospective Studies, Skin Transplantation, Mohs Surgery adverse effects, Skin Neoplasms surgery
- Abstract
Competing Interests: Conflicts of interest None disclosed.
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- 2022
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11. Incidental Staining of AE1 and AE3 in the Lactiferous Ducts During Mohs Micrographic Surgery for the Removal of Squamous Cell Carcinoma of the Chest.
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Stolarczyk A, Paul D, Mannava K, and Smith FL
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- Humans, Mohs Surgery, Staining and Labeling, Carcinoma, Basal Cell surgery, Carcinoma, Squamous Cell pathology, Carcinoma, Squamous Cell surgery, Skin Neoplasms pathology, Skin Neoplasms surgery
- Published
- 2022
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12. Practice Patterns for Mohs Surgeons of Varying Clinical Experience: A Cross-Sectional Analysis of a Medicare Claims Database.
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Singh P, Smith FL, and Brown MD
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- Aged, Analgesics, Opioid, Anti-Bacterial Agents, Benzodiazepines, Cross-Sectional Studies, Humans, Medicare, Mohs Surgery, Practice Patterns, Physicians', United States, Skin Neoplasms surgery, Surgeons
- Abstract
Background: Use of Mohs micrographic surgery (MMS) is highly prevalent, but little data are available on how surgeon experience affects surgical practice patterns., Objective: To determine differences in use of MMS among surgeons of varying experience., Materials and Methods: This cross-sectional study sampled from clinicians billing ≥200 mean annual Mohs surgery claims from the 2012 to 2018 Medicare Public Use File. The primary outcome was mean annual Mohs surgery claims for clinicians of varying experience. Secondary outcomes included use of flaps/grafts and prescribing of oral antibiotics, benzodiazepines, and opioids., Results: Among 1,759 unique surgeons, those with 16 to 20 years of experience performed the most mean annual (95% confidence interval) Mohs surgical cases (578.7 [556.7-600.6]). Surgeons with 21 to 25 years of experience prescribed the most antibiotics (240.2 [216.5-263.8] mean annual claims), whereas those with >35 years of experience prescribed the longest courses (15.3 [14.2-16.4] days)., Conclusion: Midcareer surgeons performed the most mean annual Mohs surgery cases, whereas later career surgeons prescribed more frequent and longer courses of antibiotics suggesting changing practice patterns with additional years of experience., (Copyright © 2022 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. All rights reserved.)
- Published
- 2022
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13. Enhancing the wellness of caregivers of individuals with epilepsy: The effects of a brief stress management course.
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Bautista RED, Smith FL, and Celso BG
- Subjects
- Adult, Humans, Psychotherapy, Quality of Life, Surveys and Questionnaires, Caregivers, Epilepsy therapy
- Abstract
Purpose: To determine whether a brief stress management video can improve the quality of life of caregivers of persons with epilepsy (PWE)., Methods: Thirty-three adult caregivers of PWE who scored 5 or higher on the Caregiver Self-Assessment Questionnaire (CSAQ) completed a 30-min stress management video. This was preceded by a pre-intervention assessment, followed by post-intervention assessment at 1 month, and a delayed post-intervention assessment evaluation 3 months after video was viewed. Measures of program acceptability were also obtained., Results: There was significant improvement when comparing pre- and post-intervention CSAQ scores. This improvement was sustained at 3 months post intervention. Measures of program acceptability were favorable., Conclusion: A brief stress management course can help improve the quality of life of caregivers of PWE., (Copyright © 2022 Elsevier Inc. All rights reserved.)
- Published
- 2022
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14. Perils of guide wire fracture - Unrecognized retained foreign body.
- Author
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Smith FL
- Abstract
A case is presented of retained guide wire fragment after percutaneous stone removal with probable mechanism of breakage. Nephrostomy access was obtained using Seldinger technique and the wire passed through a stenotic ureter with difficulty. After removal of the stone, the wire fragmented on removal and the upper and lower fragments were removed from above and below, respectively. Years later, recurrent stone in the kidney contained an unsuspected wire fragment. Guide wire fracture may result in multiple fragments within the urinary tract. An understanding of mechanisms of wire failure may prevent unsuspected retained foreign bodies., (© 2022 The Author.)
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- 2022
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15. Diarrhea outbreak associated with coronavirus infection in adult dairy goats.
- Author
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Smith FL, Heller MC, Crossley BM, Clothier KA, Anderson ML, Barnum SS, Pusterla N, and Rowe JD
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- Animals, Cattle, Cross-Sectional Studies, Diarrhea epidemiology, Diarrhea veterinary, Disease Outbreaks veterinary, Feces, Goats, Phylogeny, Cattle Diseases epidemiology, Coronavirus Infections epidemiology, Coronavirus Infections veterinary, Goat Diseases epidemiology
- Abstract
Background: Infection by coronaviruses cause gastrointestinal disease in many species. Little is known about its prevalence and importance in goats., Objective: Identify the etiology, demographics, and clinical features of an outbreak of diarrhea in adult goats., Hypothesis: Bovine coronavirus (BCoV) PCR would detect viral material in feces of goats in the herds involved in the diarrhea outbreak., Animals: Twelve herds with 4 to 230 adult goats were affected. Goats sampled for fecal PCR were ≥1-year-old: 25 from affected herds and 6 from a control herd., Methods: This is a cross-sectional descriptive study of an outbreak of diarrheal disease in adult goats. BCoV PCR primers for the spike (S) or nucleocapsid (N) proteins were used to test fecal material from affected goats. The N protein sequencing and phylogenetic analysis was performed. Herd records and owner surveys were used to characterize morbidity, clinical signs, and treatment., Results: In 2 affected herds 18/25 of animals had at least 1 positive BCoV PCR test. Goats from affected herds were significantly more likely to be PCR positive than the control herd (OR 8.75, 95% CI 1.11-104, P = .05). The most common clinical signs were change in fecal consistency (19/20) and decreased milk production (14/15). Phylogenetic analysis of the N protein showed this virus was closely related to a bovine-like coronavirus isolated from a giraffe., Conclusions and Clinical Importance: Bovine coronavirus primers detected nucleic acids of the N and S proteins in feces of goats in affected herds. Coronavirus shedding frequency was temporally associated with the outbreak., (© 2022 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)
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- 2022
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16. Engaging with Transformative Paradigms in Mental Health.
- Author
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Whitaker L, Smith FL, Brasier C, Petrakis M, and Brophy L
- Subjects
- Australia, Humans, Mental Health, Social Work, Mental Disorders, Mental Health Services
- Abstract
When graduates of Australian social work courses embark on a career in mental health, the systems they enter are complex, fragmented and evolving. Emerging practitioners will commonly be confronted by the loneliness, social exclusion, poverty and prejudice experienced by people living with mental distress; however, social work practice may not be focused on these factors. Instead, in accordance with the dominant biomedical perspective, symptom and risk management may predominate. Frustration with the limitations evident in this approach has seen the United Nations call for the transformation of mental health service delivery. Recognising paradigmatic influences on mental health social work may lead to a more considered enactment of person centred, recovery and rights-based approaches. This paper compares and contrasts influences of neo-liberalism, critical theory, human rights and post-structuralism on mental health social work practice. In preparing social work practitioners to recognise the influence of, and work more creatively with, intersecting paradigms, social work educators strive to foster a transformative approach to mental health practice that straddles discourses.
- Published
- 2021
- Full Text
- View/download PDF
17. A randomized controlled trial of the Transdiagnostic Intervention for Sleep and Circadian Dysfunction (TranS-C) to improve serious mental illness outcomes in a community setting.
- Author
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Harvey AG, Dong L, Hein K, Yu SH, Martinez AJ, Gumport NB, Smith FL, Chapman A, Lisman M, Mirzadegan IA, Mullin AC, Fine E, Dolsen EA, Gasperetti CE, Bukosky J, Alvarado-Martinez CG, Kilbourne AM, Rabe-Hesketh S, and Buysse DJ
- Subjects
- Adult, Anxiety therapy, Anxiety Disorders therapy, California, Female, Humans, Male, Mental Disorders complications, Middle Aged, Schizophrenia therapy, Sleep, Sleep Disorders, Circadian Rhythm complications, Sleep Wake Disorders complications, Treatment Outcome, Community Mental Health Centers, Mental Disorders therapy, Psychotherapy methods, Sleep Disorders, Circadian Rhythm therapy, Sleep Wake Disorders therapy
- Abstract
Objective: To determine if the Transdiagnostic Intervention for Sleep and Circadian Dysfunction (TranS-C) improves functional impairment, psychiatric symptoms, and sleep and circadian functioning., Method: Adults diagnosed with serious mental illness (SMI) and sleep and circadian dysfunction (N = 121) were randomly allocated to TranS-C plus usual care (TranS-C + UC; n = 61; 8 individual weekly sessions) or 6 months of Usual Care followed by Delayed Treatment with TranS-C (UC-DT; n = 60). Schizophrenia (45%) and anxiety disorders (47%) were common. Blind assessments were conducted pre-treatment, post-treatment, and 6 months later (6FU). The latter two were the post-randomization points of interest. The location was Alameda County Behavioral Health Care Services (ACBHCS), a Community Mental Health Center (CMHC) in California., Results: For the primary outcomes, relative to UC-DT, TranS-C + UC was associated with reduction in functional impairment (b = -3.18, p = 0.025, d = -0.58), general psychiatric symptoms (b = -5.88, p = 0.001, d = -0.64), sleep disturbance (b = -5.55, p < .0001, d = -0.96), and sleep-related impairment (b = -9.14, p < .0001, d = -0.81) from pre-treatment to post-treatment. These effects were maintained to 6-month follow-up (6FU; d = -0.42 to -0.82), except functional impairment (d = -0.37). For the secondary outcomes, relative to UC-DT, TranS-C + UC was associated with improvement in sleep efficiency and on the Sleep Health Composite score from pre-treatment to 6FU. TranS-C + UC was also associated with reduced total wake time and wake time variability from pre-treatment to post-treatment, as well as reduced hallucinations and delusions, bedtime variability, and actigraphy measured waking activity count variability from pre-treatment to 6FU., Conclusions: A novel transdiagnostic treatment, delivered within a CMHC setting, improves selected measures of functioning, symptoms of comorbid disorders, and sleep and circadian outcomes. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
- Published
- 2021
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18. Tophaceous gout as a squamous cell carcinoma mimicker.
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Mueller KA, Marous MR, Mannava KA, and Smith FL
- Abstract
Competing Interests: None disclosed.
- Published
- 2021
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19. The effects of a brief memory enhancement course on individuals with epilepsy.
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Bautista RED, Smith L, Smith FL, and Gautam S
- Subjects
- Humans, Memory, Quality of Life, Seizures, Epilepsy therapy, Self-Management
- Abstract
Purpose: The purpose of the study was to determine whether a brief memory enhancement course in persons with epilepsy (PWE) can improve cognitive abilities, quality of life, self-management, and seizure severity., Methods: Thirty-nine PWE completed a 1-hour memory enhancement course. This was preceded by a baseline/preintervention assessment (BA/PRE), followed by postintervention assessment (POST) at 1 & 1/2 to 3 months, and a delayed postintervention assessment evaluation (DPOST) at 4 & 1/2 to 6 months after course completion. In order to assess for retesting bias, an additional 30 PWE underwent a separate BA and PRE., Results: There was significant improvement on the Patient-Reported Outcomes Patient Information System version 2.0 Cognitive Function Abilities Subset and the Epilepsy Self-Management Scale (ESMS) on both POST and DPOST when compared with BA/PRE. Retesting bias did not occur. On ESMS subscale evaluation, significant improvement occurred on the Lifestyle Management subscale. There was no improvement in quality of life and seizure severity. There was good patient acceptability for the memory program., Conclusion: A brief memory enhancement course results in sustained improvement in cognitive functioning and self-management of PWE., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2020
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20. Comparison of Standard Electrocardiography and Smartphone-Based Electrocardiography Recorded at Two Different Anatomic Locations in Healthy Meat and Dairy Breed Does.
- Author
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Smith JS, Ward JL, Schneider BK, Smith FL, Mueller MS, and Heller MC
- Abstract
Smartphones present multiple applications for ambulatory practice. One of the newer technologies is smartphone-based electrocardiography (ECG). While this technology has been explored in horses and cattle, it has not yet been evaluated for goats. Fifteen goats of dairy and meat breeds were simultaneously tested with both a standard and smartphone-based ECG from two different anatomic locations (base apex and sternal positions). ECGs were compared for quality score, heart rate, and ECG intervals. Smartphone-based ECGs were feasible to collect in all goats under field settings. Scoring indicated higher quality scores for the standard ECG when compared to the smartphone-based ECG, and differences in smartphone ECG quality scores were noted between goats of different body types. Heart rate agreement was noted between measurements taken from smartphone-based and standard devices. ECG intervals calculated for smartphone-based ECGs were clinically similar to standard ECG. While not of the same diagnostic quality as standard ECG recordings, smartphone-based ECGs for goats present an easy to collect recording for caprine practice., (Copyright © 2020 Smith, Ward, Schneider, Smith, Mueller and Heller.)
- Published
- 2020
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21. B Cell Activation and Response Regulation During Viral Infections.
- Author
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Lam JH, Smith FL, and Baumgarth N
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- Animals, Antibody Formation, Antigen-Antibody Reactions immunology, B-Lymphocytes metabolism, Germinal Center immunology, Humans, Immunity, Innate, Influenza, Human immunology, Mice, Orthomyxoviridae Infections immunology, Antibodies, Viral immunology, B-Lymphocytes immunology, Immunity, Humoral immunology, Virus Diseases immunology
- Abstract
Acute viral infections are characterized by rapid increases in viral load, leading to cellular damage and the resulting induction of complex innate and adaptive antiviral immune responses that cause local and systemic inflammation. Successful antiviral immunity requires the activation of many immune cells, including T cells, natural killer cells, and macrophages. B cells play a unique part through their production of antibodies that can both neutralize and clear viral particles before virus entry into a cell. Protective antibodies are produced even before the first exposure of a pathogen, through the regulated secretion of so-called natural antibodies that are generated even in the complete absence of prior microbial exposure. An early wave of rapidly secreted antibodies from extrafollicular (EF) responses draws on the preexisting naive or memory repertoire of B cells to induce a strong protective response that in kinetics tightly follows the clearance of acute infections, such as with influenza virus. Finally, the generation of germinal centers (GCs) provides long-term protection through production of long-lived plasma cells and memory B cells, which shape and broaden the B cell repertoire for more effective responses following repeat exposures. In this study, we review B cell responses to acute viral infections, primarily influenza virus, from the earliest nonspecific B-1 cell to early, antigen-specific EF responses and finally to GC responses. Throughout, we address known factors that lead to distinct B cell response outcomes and discuss how their functions effect viral clearance, highlighting the critical contributions of each response type to the induction of highly protective antiviral humoral immunity.
- Published
- 2020
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22. TLR induces reorganization of the IgM-BCR complex regulating murine B-1 cell responses to infections.
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Savage HP, Kläsener K, Smith FL, Luo Z, Reth M, and Baumgarth N
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- Animals, CD5 Antigens metabolism, Disease Models, Animal, Mice, Orthomyxoviridae Infections immunology, Salmonella Infections, Animal immunology, B-Lymphocyte Subsets immunology, Immunoglobulin M metabolism, Immunologic Factors metabolism, Orthomyxoviridae immunology, Proto-Oncogene Proteins c-bcr metabolism, Salmonella typhimurium immunology, Toll-Like Receptors metabolism
- Abstract
In mice, neonatally-developing, self-reactive B-1 cells generate steady levels of natural antibodies throughout life. B-1 cells can, however, also rapidly respond to infections with increased local antibody production. The mechanisms regulating these two seemingly very distinct functions are poorly understood, but have been linked to expression of CD5, an inhibitor of BCR-signaling. Here we demonstrate that TLR-mediated activation of CD5+ B-1 cells induced the rapid reorganization of the IgM-BCR complex, leading to the eventual loss of CD5 expression, and a concomitant increase in BCR-downstream signaling, both in vitro and in vivo after infections of mice with influenza virus and Salmonella typhimurium. Both, initial CD5 expression and TLR-mediated stimulation, were required for the differentiation of B-1 cells to IgM-producing plasmablasts after infections. Thus, TLR-mediated signals support participation of B-1 cells in immune defense via BCR-complex reorganization., Competing Interests: HS, KK, FS, ZL, MR, NB No competing interests declared, (© 2019, Savage et al.)
- Published
- 2019
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23. Defining skin cancer local recurrence.
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Wysong A, Higgins S, Blalock TW, Ricci D, Nichols R, Smith FL, and Kossintseva I
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- Algorithms, Dermatology, Humans, Ophthalmology, Surgery, Plastic, Carcinoma, Basal Cell diagnosis, Carcinoma, Squamous Cell diagnosis, Melanoma diagnosis, Neoplasm Recurrence, Local diagnosis, Skin Neoplasms diagnosis
- Abstract
Definitions of skin cancer recurrence are variable and nonstandardized, which can lead to inconsistent and potentially inappropriate management of tumors of uncertain recurrence status. Defining recurrence is important given the potential association with metastasis in both melanoma and nonmelanoma skin cancer. A review of the literature across multiple disciplines involved in the care of skin cancer patients reveals that although criteria for recurrence are provided in the majority of cases, most are vague and inconsistent. Given the presumably increased morbidity and mortality associated with recurrent tumors, accurate identification and appropriate management is paramount. In addition, value-based health care necessitates validated and relevant outcome measures that are standardized and, thus, enable tracking of comparable and corresponding outcomes. A universal definition of localized skin cancer recurrence would ultimately allow for improved surveillance and informed therapeutic strategies to decrease morbidity and mortality of patients afflicted with skin cancer, the most common cancer nationwide., (Copyright © 2019. Published by Elsevier Inc.)
- Published
- 2019
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24. B-1 cell responses to infections.
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Smith FL and Baumgarth N
- Subjects
- Animals, Autoantigens immunology, Autoantigens metabolism, Homeostasis, Humans, Immunity, Cellular, Immunity, Innate, Immunomodulation, Receptors, Antigen, B-Cell genetics, Receptors, Antigen, B-Cell metabolism, Signal Transduction, B-Lymphocyte Subsets immunology, Infections immunology
- Abstract
B-1 cells represent an innate-like early-developing B cell population, whose existence as an independent lymphocyte subset has been questioned in the past. Recent molecular and lineage tracing studies have not only confirmed their unique origins and differentiation paths, they have also provided a rationale for their distinctive functionalities compared to conventional B cells. This review summarizes our current understanding of B-1 cell development, and the activation events that regulate B-1 cell responses to self and foreign antigens. We discuss the unresolved question to what extent BCR engagement, that is, antigen-specificity versus innate signaling contributes to B-1 cell's participation in tissue homeostasis and immune defense as providers of 'natural' and antigen-induced antibody responses, and as cytokine-producing immune regulators., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2019
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25. Frequency of shedding of respiratory pathogens in horses recently imported to the United States.
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Smith FL, Watson JL, Spier SJ, Kilcoyne I, Mapes S, Sonder C, and Pusterla N
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- Animals, Female, Herpesviridae Infections veterinary, Herpesviridae Infections virology, Herpesvirus 1, Equid, Herpesvirus 4, Equid, Horse Diseases epidemiology, Horse Diseases microbiology, Horse Diseases transmission, Horses microbiology, Horses virology, Male, Prospective Studies, Quarantine veterinary, Real-Time Polymerase Chain Reaction veterinary, Respiratory Tract Diseases microbiology, Respiratory Tract Diseases virology, Rhadinovirus, Streptococcal Infections microbiology, Streptococcal Infections transmission, Streptococcal Infections veterinary, Streptococcus equi, United States epidemiology, Virus Shedding, Horse Diseases virology, Respiratory Tract Diseases veterinary
- Abstract
Background: Imported horses that have undergone recent long distance transport might represent a serious risk for spreading infectious respiratory pathogens into populations of horses., Objective: To investigate the frequency of shedding of respiratory pathogens in recently imported horses., Animals: All imported horses with signed owner consent (n = 167) entering a USDA quarantine for contagious equine metritis from October 2014 to June 2016 were enrolled in the study., Methods: Prospective observational study. Enrolled horses had a physical examination performed and nasal secretions collected at the time of entry and subsequently if any horse developed signs of respiratory disease during quarantine. Samples were assayed for equine influenza virus (EIV), equine herpesvirus type-1, -2, -4, and -5 (EHV-1, -2, -4, -5), equine rhinitis virus A (ERAV), and B (ERBV) and Streptococcus equi subspecies equi (S. equi) using quantitative PCR (qPCR)., Results: Equine herpesviruses were detected by qPCR in 52% of the study horses including EHV-2 (28.7%), EHV-5 (40.7%), EHV-1 (1.2%), and EHV-4 (3.0%). Clinical signs were not correlated with being qPCR-positive for EHV-4, EHV-2, or EHV-5. None of the samples were qPCR-positive for EIV, ERAV, ERBV, and S. equi. The qPCR assay failed quality control for RNA viruses in 25% (46/167) of samples., Conclusions and Clinical Importance: Clinical signs of respiratory disease were poorly correlated with qPCR positive status for EHV-2, -4, and -5. The importance of γ-herpesviruses (EHV-2 and 5) in respiratory disease is poorly understood. Equine herpesvirus type-1 or 4 (EHV-1 or EHV-4) were detected in 4.2% of horses, which could have serious consequences if shedding animals entered a population of susceptible horses. Biosecurity measures are important when introducing recently imported horses into resident US populations of horses., (Copyright © 2018 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)
- Published
- 2018
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26. Equine idiopathic hemorrhagic cystitis: Clinical features and comparison with bladder neoplasia.
- Author
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Smith FL, Magdesian KG, Michel AO, Vaughan B, and Reilly CM
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- Animals, Cystitis diagnosis, Cystitis pathology, Diagnosis, Differential, Female, Hematuria diagnosis, Hematuria pathology, Horse Diseases diagnosis, Horses, Male, Retrospective Studies, Urinary Bladder pathology, Urinary Bladder Neoplasms diagnosis, Urinary Bladder Neoplasms pathology, Cystitis veterinary, Hematuria veterinary, Horse Diseases pathology, Urinary Bladder Neoplasms veterinary
- Abstract
Background: A new syndrome of hematuria in horses has been documented., Hypothesis/objectives: Hemorrhagic cystitis is a novel cause of stranguria and hematuria in horses. This syndrome may be difficult to differentiate from bladder neoplasia because they share several clinical features., Animals: Eleven horses with idiopathic hemorrhagic cystitis and 7 horses with bladder neoplasia., Methods: Retrospective cohort study., Results: Hemorrhagic cystitis was detected on cystoscopy of affected horses, with hemorrhagic and thickened apical bladder mucosa. Clinical signs and endoscopic appearance of the bladder resolved within 3-8 weeks. Histopathology of bladder mucosal biopsy specimens featured neutrophilic and hemorrhagic cystitis. Histopathology was suggestive of dysplasia or neoplasia in 3 horses with hemorrhagic cystitis, yet the horses experienced complete resolution, suggesting that small biopsy specimens obtained by endoscopy can be difficult to interpret. Horses with bladder neoplasia had lower hematocrits, were older, more likely to be female, and more likely to have a mass detected on ultrasonographic examination of the bladder than horses with hemorrhagic cystitis syndrome., Conclusions and Clinical Importance: Hemorrhagic cystitis represents a novel differential diagnosis for horses with hematuria, and is associated with a favorable prognosis. Although histopathology may suggest a neoplastic process, affected horses should be monitored cystoscopically, because complete resolution of hemorrhagic cystitis occurs. The cause of this disease is unknown, and warrants investigation., (Copyright © 2018 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)
- Published
- 2018
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27. Primary cutaneous cryptococcosis presenting as an extensive eroded plaque.
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Smith FL, Mercurio MG, and Poligone B
- Subjects
- Aged, 80 and over, Antifungal Agents administration & dosage, Antifungal Agents therapeutic use, Arm, Cryptococcosis complications, Cryptococcosis drug therapy, Cryptococcosis pathology, Diagnosis, Differential, Female, Fluconazole administration & dosage, Fluconazole therapeutic use, Humans, Skin Ulcer etiology, Cryptococcosis diagnosis, Cryptococcus neoformans isolation & purification
- Published
- 2017
28. A transdiagnostic sleep and circadian treatment to improve severe mental illness outcomes in a community setting: study protocol for a randomized controlled trial.
- Author
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Harvey AG, Hein K, Dong L, Smith FL, Lisman M, Yu S, Rabe-Hesketh S, and Buysse DJ
- Subjects
- Adult, California, Clinical Protocols, Female, Humans, Male, Mental Disorders diagnosis, Mental Disorders physiopathology, Mental Disorders psychology, Middle Aged, Prospective Studies, Research Design, Severity of Illness Index, Sleep Disorders, Circadian Rhythm diagnosis, Sleep Disorders, Circadian Rhythm physiopathology, Sleep Disorders, Circadian Rhythm psychology, Surveys and Questionnaires, Time Factors, Treatment Outcome, Young Adult, Circadian Rhythm, Mental Disorders therapy, Psychotherapy methods, Sleep, Sleep Disorders, Circadian Rhythm therapy
- Abstract
Background: Severe mental illness (SMI) is common, chronic and difficult to treat. Sleep and circadian dysfunctions are prominent correlates of SMI, yet have been minimally studied in ways that reflect the complexity of the sleep problems experienced. Prior treatment studies have been disorder-focused-they have treated a specific sleep problem in a specific diagnostic group. However, real life sleep and circadianproblems are not so neatly categorized, particularly in SMI where features of insomnia overlap with hypersomnia, delayed sleep phase and irregular sleep-wake schedules. Accordingly, the aim of this studyprotocol is to test the hypothesis that a Transdiagnostic Intervention for Sleep and Circadian Dysfunction (TranS-C) will improve functional impairment, disorder-focused symptoms and sleep and circadian functioning. Participants across DSM diagnoses and across common sleep and circadian problems are eligible. The elements of TranS-C are efficacious across SMI in research settings with research-based providers. The next step is to test TranS-C in a community setting. Accordingly, this study is being conducted within Alameda County Behavioral Health Care Services (ACBHCS), the Community Mental Health Centre (CMHC) for Alameda County., Methods/design: 120 adults diagnosed with SMI and sleep and circadian dysfunction within ACBHCS will be randomly allocated to TranS-C (n = 60) or 6-months of Usual Care followed by Delayed Treatment with TranS-C (UC-DT; n = 60). TranS-C is modularized and delivered across eight to twelve 50-minute, weekly, individual sessions. All participants will be assessed before and immediately following treatment and again 6 months later. Primary analysis will examine whether TranS-C significantly improves functional impairment, disorder-specific symptoms and sleep and circadian functioning, relative to UC-DT. Exploratory analysis will examine whether improvements in sleep and circadian functioning predict reduction in functional impairment and disorder-specific symptoms, and whether the intervention effects are mediated by improved sleep and circadian functioning and moderated by previously reported risk factors (demographics, symptom severity, medications, psychiatric and medical comorbidity)., Discussion: This trial tests an important and understudied mechanism-dysregulated sleep and circadian rhythms-in SMI, a novel transdiagnostic treatment approach, in a community setting so as to contribute to the goal of bridging the gap between research and practice., Trial Registration: ClinicalTrials.gov identifier: NCT02469233 . Registered on 9 June 2015.
- Published
- 2016
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29. Organ of Corti explants direct tonotopically graded morphology of spiral ganglion neurons in vitro.
- Author
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Smith FL and Davis RL
- Subjects
- Animals, Cells, Cultured, Coculture Techniques, Fluorescent Antibody Technique, In Vitro Techniques, Mice, Organ of Corti cytology, Spiral Ganglion cytology
- Abstract
The spiral ganglion is a compelling model system to examine how morphological form contributes to sensory function. While the ganglion is composed mainly of a single class of type I neurons that make simple one-to-one connections with inner hair cell sensory receptors, it has an elaborate overall morphological design. Specific features, such as soma size and axon outgrowth, are graded along the spiral contour of the cochlea. To begin to understand the interplay between different regulators of neuronal morphology, we cocultured neuron explants with peripheral target tissues removed from distinct cochlear locations. Interestingly, these "hair cell microisolates" were capable of both increasing and decreasing neuronal somata size, without adversely affecting survival. Moreover, axon characteristics elaborated de novo by the primary afferents in culture were systematically regulated by the sensory endorgan. Apparent peripheral nervous system (PNS)-like and central nervous system (CNS)-like axonal profiles were established in our cocultures allowing an analysis of putative PNS/CNS axon length ratios. As predicted from the in vivo organization, PNS-like axon bundles elaborated by apical cocultures were longer than their basal counterparts and this phenotype was methodically altered when neuron explants were cocultured with microisolates from disparate cochlear regions. Thus, location-dependent signals within the organ of Corti may set the "address" of neurons within the spiral ganglion, allowing them to elaborate the appropriate tonotopically associated morphological features in order to carry out their signaling function. J. Comp. Neurol. 524:2182-2207, 2016. © 2015 Wiley Periodicals, Inc., (© 2015 Wiley Periodicals, Inc.)
- Published
- 2016
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30. "Boomerang Technique: " Simple Excision With Periosteal Suspension for Correction of Mild-to-Moderate Cicatricial Ectropion.
- Author
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Fancher W, Smith FL, and Mellette R
- Subjects
- Cicatrix complications, Ectropion etiology, Humans, Male, Middle Aged, Mohs Surgery adverse effects, Carcinoma, Basal Cell surgery, Dermatologic Surgical Procedures methods, Ectropion surgery, Eyelid Neoplasms surgery
- Published
- 2016
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31. Time-kill Kinetics of a Novel Antimicrobial Silver Wound Gel Against Select Wound Pathogens.
- Author
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Lee Y, Atchley DH, Proctor CA, Smith FL, Yi S, Loftis CM, and Yates KM
- Subjects
- Administration, Topical, Bandages, Candida albicans drug effects, Escherichia coli drug effects, Gels administration & dosage, Gels pharmacology, Humans, Methicillin-Resistant Staphylococcus aureus drug effects, Microbial Sensitivity Tests, Pseudomonas aeruginosa drug effects, Skin Ulcer microbiology, Staphylococcus aureus drug effects, Time Factors, Treatment Outcome, Wound Healing drug effects, Anti-Infective Agents administration & dosage, Anti-Infective Agents pharmacology, Silver Compounds administration & dosage, Silver Compounds pharmacology, Wound Infection microbiology
- Abstract
Unlabelled: New treatments are needed as infection risk associated with diabetic, venous, and pressure ulcers are becoming more prevalent as comorbidities of obesity, aging, and major disease. Postsurgical, burn, and immunocompromised patients are also at an increased risk of wounds and infection. Silver has been utilized in treating various wounds associated with infections and, although highly effective, caution is required for use beyond 2 weeks due to potential silver cytotoxicity. To overcome this obstacle, an antimicrobial wound gel (CelaCare Technologies, Inc, Dallas, TX) was designed to allow low concentrations of a proprietary silver salt combined with acemannan, which has been demonstrated to aid wound healing., Materials and Methods: This study's objective was to determine the time-kill kinetics of the antimicrobial wound gel vs 4 commercial topical silver products against 6 common wound pathogens and Bacillus subtilis as a spore-forming bacteria., Results: The antimicrobial wound gel achieved a 2.9 log reduction in growth of Pseudomonas aeruginosa within 30 minutes, a 2.3 log reduction in Streptococcus pyogenes within 8 hours, a 2.1 log reduction in methicillin-resistant Staphylococcus aureus within 48 hours, a 2.3 log reduction in S. aureus within 24 hours, a 4.1 log reduction in Escherichia coli within 30 minutes, a 2.9 log reduction in B. subtilis within 60 minutes, and a 3.4 log reduction in Candida albicans within 90 minutes. Overall, the antimicrobial wound gel demonstrated broad antimicrobial coverage against all wound pathogens evaluated, and it was comparable to, or better than, other tested topical silver products containing substantially higher silver concentrations., Conclusion: The broad-spectrum antimicrobial activity of the wound gel indicates it could become a product alternative to current commercial products.
- Published
- 2015
32. Advancing science diplomacy: Indonesia and the US Naval Medical Research Unit.
- Author
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Smith FL 3rd
- Subjects
- History, 20th Century, History, 21st Century, Indonesia, Military Personnel, United States, Biomedical Research history, International Cooperation history
- Abstract
Science diplomacy supposedly builds international cooperation through scientific and technical exchange. In practice, however, there are important but often overlooked instances where it might create conflict instead--as with accusations of espionage surrounding the US Naval Medical Research Unit 2 (NAMRU-2) in Indonesia. Did American science diplomacy backfire in Indonesia and, if so, why? Most literature fails to anticipate this possibility, let alone explain it, since science diplomacy is rarely subject to critical analysis. Rather than shun politics or, similarly, simply blame the demise of NAMRU-2 on the military or avian influenza, I consider both the successes and failures of this research unit in the context of Indonesia's transition to democracy and America's legacy from the Cold War. Based on this history, I propose that the effects of science diplomacy depend on strategic communication and exchange, as well as elite influence and material incentives. Therefore, by challenging the conventional wisdom about science diplomacy, NAMRU-2 can help advance the theory and practice of this potentially useful tool of statecraft.
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- 2014
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33. Antipodal biosecurity? Oversight of dual use research in the United States and australia.
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Smith FL 3rd and Kamradt-Scott A
- Published
- 2014
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34. The POLST paradigm and form:Facts and analysis.
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Brugger C, Breschi LC, Hart EM, Kummer M, Lane JI, Morrow PT, Smith FL, Toffler WL, Beffel M, Brehany JF, Buscher S, and Marker RL
- Abstract
This white paper, prepared by a working group of the Catholic Medical Association, provides a commentary on a new type of end-of-life document called a POLST form (Physician Orders for Life-Sustaining Treatment) as well as on its model (or "paradigm") for implementation across the United States. After an introductory section reviewing the origin, goals, and standard defenses of the POLST paradigm and form, the paper offers a critical analysis of POLST, including an analysis of the risks that POLST poses to sound clinical and ethical decision-making. The paper ends with several recommendations to help Catholic healthcare professionals and institutions better address the challenges of end-of-life care with alternatives to POLST.
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- 2013
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35. A pilot study to assess cognition and pillbox fill accuracy by community-dwelling older adults.
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Lam AY, Anderson K, Borson S, and Smith FL
- Subjects
- Aged, Aged, 80 and over, Female, Humans, Male, Medication Adherence, Neuropsychological Tests, Pilot Projects, Polypharmacy, Residence Characteristics, Self Administration, Cognition, Medication Errors prevention & control, Medication Therapy Management
- Abstract
Objective: To assess pillbox fill accuracy and cognition among community-dwelling older adults., Design: A descriptive, cross-sectional study., Setting: Retail pharmacy., Participants: Convenience sample of English-speaking adults older than 60 years of age without dementia, taking more than four medications, and naive to Mediset use., Interventions: In face-to-face interviews, subjects provided demographic, medical, and medication information, completed the Mini-Cog and Medi-Cog (combination of Mini-Cog and medication-transfer screen [MTS]), and filled their own medications in a pillbox. Data were analyzed using descriptive statistics and stepwise regression analysis with correctly filled pill count (PC) as the dependent variable and the cognitive screens as independent variables., Main Outcome Measures: Accuracy of the Mini-Cog, MTS, and Medi-Cog in predicting PC., Results: Among 50 subjects (58% female, mean age 76.4 years), only one subject failed to pass the Mini-Cog and two failed to reach the criterion level of correctly filled PC. The mean (standard deviation) Mini-Cog score for the sample was 4.38 (0.81), MTS score was 4.1 (1.31), Medi-Cog score was 8.48 (1.82), and the mean PC was 97% (8%). The Mini-Cog and MTS individually accounted for about 30% of the variance (P < 0.001); the Medi-Cog accounted for 44% of the variance (P < 0.001), indicating strongest PC prediction., Conclusion: Nearly all study participants filled pillboxes accurately. The Medi-Cog was the strongest predictor of pillbox fill accuracy. Future studies of medication self-management abilities among community-dwelling older adults should include representative samples of this population, comprehensive assessment of health status, cognitive screening, pillbox fill accuracy, and the utilization of medications in filled pillboxes.
- Published
- 2011
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36. The effect of protein kinase C and G protein-coupled receptor kinase inhibition on tolerance induced by mu-opioid agonists of different efficacy.
- Author
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Hull LC, Llorente J, Gabra BH, Smith FL, Kelly E, Bailey C, Henderson G, and Dewey WL
- Subjects
- Animals, Brain physiology, Drug Interactions, Drug Tolerance, Enkephalin, Ala(2)-MePhe(4)-Gly(5)- pharmacology, Fentanyl pharmacology, In Vitro Techniques, Locus Coeruleus drug effects, Locus Coeruleus physiology, Male, Meperidine pharmacology, Mice, Mice, Inbred C57BL, Morphine pharmacology, Neurons drug effects, Neurons physiology, Patch-Clamp Techniques, Analgesics, Opioid pharmacology, Brain drug effects, G-Protein-Coupled Receptor Kinases antagonists & inhibitors, Protein Kinase C antagonists & inhibitors, Receptors, Opioid, mu agonists
- Abstract
Differences in the mechanisms underlying tolerance and mu-opioid receptor desensitization resulting from exposure to opioid agonists of different efficacy have been suggested previously. The objective of this study was to determine the effects of protein kinase C (PKC) and G protein-coupled receptor kinase (GRK) inhibition on antinociceptive tolerance in vivo to opioid agonists of different efficacy. A rapid (8-h) tolerance-induction model was used where each opioid was repeatedly administered to naive mice. Animals were then challenged with the opioid after injection of a kinase inhibitor to determine its effects on the level of tolerance. Tolerance to meperidine, morphine, or fentanyl was fully reversed by the PKC inhibitor 12-(2-cyanoethyl)-6,7,12,13-tetrahydro-13-methyl-5-oxo-5H-indolo(2,3-a)pyrrolo(3,4-c)carbazole (Gö6976). However, in vivo tolerance to [d-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin (DAMGO) was not reversed by PKC inhibition. The novel small-molecule GRK inhibitors beta-adrenergic receptor kinase 1 inhibitor and 2-(8-[(dimethylamino) methyl]-6,7,8,9-tetrahydropyridol[1,2-a]indol-3-yl)-3-(1-methylindol-3-yl)maleimide (Ro 32-0432) did not reverse the tolerance to meperidine, fentanyl, or morphine but did reverse the tolerance to DAMGO. To correlate GRK-dependent DAMGO-induced tolerance with mu-opioid receptor desensitization, we used in vitro whole-cell patch-clamp recording from mouse locus coeruleus neurons and observed that the GRK inhibitors reduced DAMGO-induced desensitization of mu-opioid receptors, whereas the PKC inhibitor had no effect. These results suggest that tolerance induced by low- and moderate-efficacy mu-opioid receptor agonists is dependent on PKC, whereas tolerance induced by the high-efficacy agonist DAMGO is dependent on GRK.
- Published
- 2010
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37. Role of protein kinase C and mu-opioid receptor (MOPr) desensitization in tolerance to morphine in rat locus coeruleus neurons.
- Author
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Bailey CP, Llorente J, Gabra BH, Smith FL, Dewey WL, Kelly E, and Henderson G
- Subjects
- Animals, Computer Simulation, Locus Coeruleus cytology, Locus Coeruleus metabolism, Male, Narcotics pharmacology, Neurons metabolism, Organ Culture Techniques, Protein Kinase C metabolism, Rats, Rats, Wistar, Receptors, Opioid, mu metabolism, Drug Tolerance physiology, Locus Coeruleus drug effects, Morphine pharmacology, Neurons drug effects, Protein Kinase C drug effects, Receptors, Opioid, mu drug effects
- Abstract
In morphine tolerance a key question that remains to be answered is whether mu-opioid receptor (MOPr) desensitization contributes to morphine tolerance, and if so by what cellular mechanisms. Here we demonstrate that MOPr desensitization can be observed in single rat brainstem locus coeruleus (LC) neurons following either prolonged (> 4 h) exposure to morphine in vitro or following treatment of animals with morphine in vivo for 3 days. Analysis of receptor function by an operational model indicated that with either treatment morphine could induce a profound degree (70-80%) of loss of receptor function. Ongoing PKC activity in the MOPr-expressing neurons themselves, primarily by PKCalpha, was required to maintain morphine-induced MOPr desensitization, because exposure to PKC inhibitors for only the last 30-50 min of exposure to morphine reduced the MOPr desensitization that was induced both in vitro and in vivo. The presence of morphine was also required for maintenance of desensitization, as washout of morphine for > 2 h reversed MOPr desensitization. MOPr desensitization was homologous, as there was no change in alpha(2)-adrenoceptor or ORL1 receptor function. These results demonstrate that prolonged morphine treatment induces extensive homologous desensitization of MOPrs in mature neurons, that this desensitization has a significant PKC-dependent component and that this desensitization underlies the maintenance of morphine tolerance.
- Published
- 2009
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38. Pre-treatment with a PKC or PKA inhibitor prevents the development of morphine tolerance but not physical dependence in mice.
- Author
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Gabra BH, Bailey CP, Kelly E, Smith FL, Henderson G, and Dewey WL
- Subjects
- Animals, Cyclic AMP-Dependent Protein Kinases drug effects, Injections, Intraventricular, Male, Mice, Morphine pharmacology, Pain Threshold drug effects, Protein Kinase C drug effects, Substance Withdrawal Syndrome enzymology, Cyclic AMP-Dependent Protein Kinases metabolism, Drug Tolerance physiology, Enzyme Inhibitors administration & dosage, Morphine Dependence enzymology, Protein Kinase C metabolism
- Abstract
We previously demonstrated that intracerebroventricular (i.c.v.) administration of protein kinase C (PKC) or protein kinase A (PKA) inhibitors reversed morphine antinociceptive tolerance in 3-day morphine-pelleted mice. The present study aimed at evaluating whether pre-treating mice with a PKC or PKA inhibitor prior to pellet implantation would prevent the development of morphine tolerance and physical dependence. Antinociception was assessed using the warm-water tail immersion test and physical dependence was evaluated by quantifying/scoring naloxone-precipitated withdrawal signs. While drug-naïve mice pelleted with a 75 mg morphine pellet for 3 days developed a 5.8-fold tolerance to morphine antinociception, mice pre-treated i.c.v. with the PKC inhibitors bisindolylmaleimide I, Go-7874 or Go-6976, or with the myristoylated PKA inhibitor, PKI-(14-22)-amide failed to develop any tolerance to morphine antinociception. Experiments were also conducted to determine whether morphine-pelleted mice were physically dependent when pre-treated with PKC or PKA inhibitors. The same inhibitor doses that prevented morphine tolerance were evaluated in other mice injected s.c. with naloxone and tested for precipitated withdrawal. The pre-treatment with PKC or PKA inhibitors failed to attenuate or block the signs of morphine withdrawal including jumping, wet-dog shakes, rearing, forepaw tremor, increased locomotion, grooming, diarrhea, tachypnea and ptosis. These data suggest that elevations in the activity of PKC and PKA in the brain are critical to the development of morphine tolerance. However, it appears that tolerance can be dissociated from physical dependence, indicating a role for PKC and PKA to affect antinociception but not those signs mediated through the complex physiological processes of withdrawal.
- Published
- 2008
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39. mGluR5 antagonists that block calcium mobilization in vitro also reverse (S)-3,5-DHPG-induced hyperalgesia and morphine antinociceptive tolerance in vivo.
- Author
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Gabra BH, Smith FL, Navarro HA, Carroll FI, and Dewey WL
- Subjects
- Analgesics, Opioid agonists, Animals, Calcium Signaling physiology, Central Nervous System drug effects, Central Nervous System metabolism, Central Nervous System physiopathology, Dose-Response Relationship, Drug, Excitatory Amino Acid Agonists pharmacology, Glutamic Acid metabolism, Glycine analogs & derivatives, Glycine pharmacology, Hyperalgesia chemically induced, Hyperalgesia metabolism, Male, Mice, Nociceptors drug effects, Nociceptors metabolism, Pain chemically induced, Pain drug therapy, Pain metabolism, Placebo Effect, Pyridines chemistry, Pyridines pharmacology, Receptor, Metabotropic Glutamate 5, Receptors, Metabotropic Glutamate metabolism, Resorcinols pharmacology, Synaptic Transmission drug effects, Synaptic Transmission physiology, Calcium Signaling drug effects, Drug Tolerance physiology, Excitatory Amino Acid Antagonists pharmacology, Hyperalgesia drug therapy, Morphine agonists, Receptors, Metabotropic Glutamate antagonists & inhibitors
- Abstract
The present study comparatively evaluated the potency of a series of new phenylethyl[1,2,4]methyltriazines which are analogues of the classical metabotropic glutamate (mGlu) receptor subtype 5 (mGluR5) antagonist 2-methyl-6-(phenylethynyl)pyridine (MPEP) in blocking hyperalgesia induced by the group I mGlu receptor agonist (S)-3,5-DHPG as well as in reversing morphine antinociceptive tolerance in mice. Hyperalgesia was assessed in mice using the tail immersion test. Intrathecal (i.t.) pre-treatment with the test compounds 5-methyl-3-phenylethynyl-[1,2,4]triazine (RTI-4229-707), 5-methyl-3-(4-phenoxy-phenylethynyl-[1,2,4]triazine (RTI-4229-766), and 3-(3-methylphenylethynyl)-5-methyl-[1,2,4]triazine (RTI-4229-787) resulted in a dose-dependent blockade of (S)-3,5-DHPG-induced hyperalgesia. The inhibitory dose-50 (ID(50)) values were 0.49, 0.72 and 0.44 nmol/mouse, for RTI-4229-707, RTI-4229-766 and RTI-4229-787, respectively, compared to 18.63 nmol/mouse for MPEP. The other two compounds tested 3-(2,5-dimethylphenylethynyl)-5-methyl[1,2,4]triazine (RTI-4229-785) and 3-(2-methylphenylethynyl)-5-methyl[1,2,4]triazine (RTI-4229-828) were totally inactive. Morphine tolerance was induced in mice by implanting a 75 mg morphine pellet and assessing morphine-induced antinociception 72-h later. The morphine-pelleted mice showed a 5.5-fold tolerance to the antinociceptive effect of acute morphine compared to placebo-pelleted mice in the tail immersion test. Intracerebroventricular (i.c.v.) administration of the three active mGluR5 antagonists dose-dependently reversed morphine antinociceptive tolerance. The ID(50) values were 57.7, 25.8 and 64.3 nmol/mouse, for RTI-4229-707, RTI-4229-766 and RTI-4229-787, respectively, compared to 1050 nmol/mouse for MPEP. Similar to the hyperalgesia study, test compounds RTI-4229-785 and RTI-4229-828 were totally inactive in reversing morphine tolerance. These results are in agreement with our previous study in which we demonstrated that the same active mGluR5 antagonists blocked glutamate-mediated mobilization of internal calcium in a selective mGluR5 in vitro efficacy assay.
- Published
- 2008
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40. Region-dependent attenuation of mu opioid receptor-mediated G-protein activation in mouse CNS as a function of morphine tolerance.
- Author
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Sim-Selley LJ, Scoggins KL, Cassidy MP, Smith LA, Dewey WL, Smith FL, and Selley DE
- Subjects
- Analgesics, Opioid administration & dosage, Animals, Binding Sites, Central Nervous System, Dose-Response Relationship, Drug, Guanosine 5'-O-(3-Thiotriphosphate), Hypothermia chemically induced, Male, Mice, Morphine administration & dosage, Pain Measurement, Posterior Horn Cells, Solitary Nucleus, Tail drug effects, Analgesics, Opioid pharmacology, Drug Tolerance, GTP-Binding Proteins metabolism, Morphine pharmacology, Receptors, Opioid, mu metabolism
- Abstract
Background and Purpose: Chronic morphine administration produces tolerance in vivo and attenuation of mu opioid receptor (MOR)-mediated G-protein activation measured in vitro, but the relationship between these adaptations is not clear. The present study examined MOR-mediated G-protein activation in the CNS of mice with different levels of morphine tolerance., Experimental Approach: Mice were implanted with morphine pellets, with or without supplemental morphine injections, to induce differing levels of tolerance as determined by a range of MOR-mediated behaviours. MOR function was measured using agonist-stimulated [(35)S]guanylyl-5'-O-(gamma-thio)-triphosphate ([(35)S]GTPgammaS) and receptor binding throughout the CNS., Key Results: Morphine pellet implantation produced 6-12-fold tolerance in antinociceptive assays, hypothermia and Straub tail, as measured by the ratio of morphine ED(50) values between morphine-treated and control groups. Pellet implantation plus supplemental injections produced 25-50-fold tolerance in these tests. In morphine pellet-implanted mice, MOR-stimulated [(35)S]GTPgammaS binding was significantly reduced only in the nucleus tractus solitarius (NTS) and spinal cord dorsal horn in tissue sections from morphine pellet-implanted mice. In contrast, MOR-stimulated [(35)S]GTPgammaS binding was significantly decreased in most regions examined in morphine pellet+morphine injected mice, including nucleus accumbens, caudate-putamen, periaqueductal gray, parabrachial nucleus, NTS and spinal cord., Conclusions and Implications: Tolerance and the regional pattern of apparent MOR desensitization were influenced positively by the level of morphine exposure. These results indicate that desensitization of MOR-mediated G-protein activity is more regionally widespread upon induction of high levels of tolerance, suggesting that this response contributes more to high than low levels of tolerance to CNS-mediated effects of morphine.
- Published
- 2007
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41. Evidence for an important role of protein phosphatases in the mechanism of morphine tolerance.
- Author
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Gabra BH, Bailey CP, Kelly E, Sanders AV, Henderson G, Smith FL, and Dewey WL
- Subjects
- Analysis of Variance, Animals, Drug Interactions, Enzyme Inhibitors administration & dosage, Injections, Intraventricular, Male, Mice, Morphine administration & dosage, Narcotics administration & dosage, Pain Measurement, Periaqueductal Gray drug effects, Periaqueductal Gray metabolism, Reaction Time drug effects, Behavior, Animal drug effects, Drug Tolerance physiology, Morphine pharmacology, Narcotics pharmacology, Phosphoprotein Phosphatases physiology
- Abstract
Acute morphine antinociception has been shown to be blocked by very low picogram doses of okadaic acid indicating that inhibition of protein phosphatase PP2A allows for increases in phosphorylation to inhibit antinociception. Comparative studies in morphine tolerant animals have not been reported. In the present study, we showed a significant increase in the total phosphatase activity in the periaqueductal gray matter (PAG) from morphine-pelleted versus placebo-pelleted mice, 72-h after pellet implantation. This supports our hypothesis that phosphatase activity is increased in tolerance as a compensatory mechanism for the increase in kinase activity during the development of tolerance. We also demonstrated that i.c.v. administration of the phosphatase inhibitor okadaic acid (3 pmol/mouse; a dose tested to be inert in placebo-pelleted mice) enhanced the level of morphine antinociceptive tolerance assessed by the tail immersion test, 72-h following pellet implantation. This was supported by the fact that the same treatment with okadaic acid blocked the increase in phosphatase activity in PAG of morphine tolerant mice indicating that selective inhibition of PP2A contributes to enhanced levels of morphine tolerance. We have previously reported that PKC or PKA inhibitors reversed morphine antinociceptive tolerance in mice. The current study shows that i.c.v. administration of the PKC inhibitors bisindolylmaleimide I or Go6976 reversed the enhanced level of morphine tolerance induced by okadaic acid treatment to the same level of tolerance observed in non-okadaic acid-treated tolerant mice. However, the PKA inhibitor PKI-(14-22)-amide only partially reversed the enhancement of morphine tolerance induced by okadaic acid. Our data suggest an important role for the balance between kinases and phosphatases in modulating tolerance levels. Further studies will be directed towards a better understanding of the role of different phosphatase isoforms in morphine tolerance.
- Published
- 2007
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42. Synthesis and pharmacological evaluation of phenylethynyl[1,2,4]methyltriazines as analogues of 3-methyl-6-(phenylethynyl)pyridine.
- Author
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Carroll FI, Kotturi SV, Navarro HA, Mascarella SW, Gilmour BP, Smith FL, Gabra BH, and Dewey WL
- Subjects
- Drug Evaluation, Preclinical, Magnetic Resonance Spectroscopy, Pyridines chemistry, Triazines chemical synthesis, Triazines pharmacology
- Abstract
Procedures were developed for the synthesis of 3-methyl-5-phenylethynyl[1,2,4]triazine (4), 6-methyl-3-phenylethynyl[1,2,4]triazine (5), and 5-methyl-3-phenylethynyl[1,2,4]triazine (6a) as analogues of 2-methyl-6-(phenylethynyl)pyridine (2). The compounds were evaluated for antagonism of glutamate-mediated mobilization of internal calcium in an mGluR5 in vitro efficacy assay. The most potent of the three analogues was 6a. Twenty additional analogues of 6a were synthesized and evaluated for mGluR5 antagonist efficacy. The most potent compounds were 3-(3-methylphenylethynyl)-5-methyl[1,2,4]triazine (6b), 5-(3-chlorophenylethynyl)-5-methyl[1,2,4]triazine (6c), and 3-(3-bromophenylethynyl)-5-methyl[1,2,4]triazine (6d).
- Published
- 2007
- Full Text
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43. Decrease in N-methyl-D-aspartic acid receptor-NR2B subunit levels by intrathecal short-hairpin RNA blocks group I metabotropic glutamate receptor-mediated hyperalgesia.
- Author
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Gabra BH, Kessler FK, Ritter JK, Dewey WL, and Smith FL
- Subjects
- Animals, Excitatory Amino Acid Antagonists pharmacology, Gene Silencing, Glycine analogs & derivatives, Glycine pharmacology, Hyperalgesia etiology, Male, Mice, Pain drug therapy, Receptors, Metabotropic Glutamate physiology, Receptors, N-Methyl-D-Aspartate analysis, Receptors, N-Methyl-D-Aspartate genetics, Receptors, N-Methyl-D-Aspartate physiology, Resorcinols pharmacology, Signal Transduction, Hyperalgesia prevention & control, RNA, Small Interfering pharmacology, Receptors, Metabotropic Glutamate antagonists & inhibitors, Receptors, N-Methyl-D-Aspartate antagonists & inhibitors
- Abstract
The present study characterizes the involvement of the N-methyl-D-aspartic acid receptors (NMDARs) in mediating thermal hyperalgesia induced by activation of group I metabotropic glutamate receptors (mGluRs). Intrathecal administration of the mGluR1/5 agonist (S)-3,5-DHPG [(S)-3,5-dihydroxyphenylglycine] to mice resulted in significant hyperalgesia as assessed by the tail immersion test. The pretreatment of mice i.t. with CGS 19755 (selective antagonist of the NMDAR), CGP 78608 [[(1S)-1-[[(7-bromo-1,2,3,4-tetrahydro-2,3-dioxo-5-quinoxalinyl)methyl]amino]ethyl]phosphonic acid] (selective antagonist at the glycine-binding site of the NMDAR), ifenprodil and Ro 25-6981 (selective antagonists of the NR2B subunit of the NMDAR), bisindolylmaleimide I and Go-7874 [12-(2-cyanoethyl)-6,7,12,13-tetrahydro-13-methyl-5-oxo-5H-indolo(2,3-a)pyrrolo(3,4-c)-carbazole] (inhibitors of protein kinase C), or PKI-(14-22)-amide [Myr-N-Gly-Arg-Thr-Gly-Arg-Arg-Asn-Ala-Ile-NH(2)] (inhibitor of protein kinase A) dose-dependently inhibited the hyperalgesia induced by i.t. administration of the mGluR1/5 receptor agonist (S)-3,5-DHPG. In contrast, i.t. pretreatment of mice with NVP-AAM077 [[(R)-[(S)-1-(4-bromophenyl)-ethylamino]-(2,3-dioxo-1,2,3,4-tetrahydroquinoxalin-5-yl)-methyl]-phosphonic acid] (selective antagonist of the NR2A subunit of the NMDAR) or DT-3 [H-Arg-Gln-Ile-Lys-Ile-Trp-Phe-Gln-Asn-Arg-Arg-Met-Lys-Trp-Lys-Lys-Leu-Arg-Lys-Lys-Lys-Lys-Lys-His-OH] (inhibitor of protein kinase G) had no effect on (S)-3,5-DHPG-mediated hyperalgesia. We also show for the first time that i.t. injection of pSM2 (pShag Magic version 2)-grin2b (coding for an short-hairpin RNA to the NR2B subunit of the NMDAR) resulted in a dose-dependent decrease in the NR2B protein and blockade of hyperalgesia induced by activation of the mGluR1/5 in (S)-3,5-DHPG-treated mice. Taken together, our results suggest the hypothesis that mGluRs are coupled to the NMDAR channels through the NR2B subunit in the spinal cord and that this coupling involves the activation of protein kinase C and protein kinase A.
- Published
- 2007
- Full Text
- View/download PDF
44. Enhancement of bupivacaine local anesthesia with the potassium channel blocker ibutilide.
- Author
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Smith FL and Lindsay RJ
- Subjects
- Adrenergic alpha-Agonists pharmacology, Adrenergic alpha-Agonists therapeutic use, Anesthetics, Local therapeutic use, Animals, Anti-Arrhythmia Agents pharmacology, Anti-Arrhythmia Agents therapeutic use, Bupivacaine therapeutic use, Cell Membrane drug effects, Cell Membrane metabolism, Drug Combinations, Drug Synergism, Epinephrine pharmacology, Epinephrine therapeutic use, Male, Mice, Mice, Inbred ICR, Nerve Fibers, Unmyelinated drug effects, Nerve Fibers, Unmyelinated metabolism, Neurons, Afferent drug effects, Neurons, Afferent metabolism, Nociceptors drug effects, Nociceptors metabolism, Pain metabolism, Pain physiopathology, Potassium Channel Blockers therapeutic use, Potassium Channels drug effects, Potassium Channels metabolism, Sulfonamides therapeutic use, Anesthesia, Local methods, Anesthetics, Local pharmacology, Bupivacaine pharmacology, Pain drug therapy, Potassium Channel Blockers pharmacology, Sulfonamides pharmacology
- Abstract
In some clinical settings it is necessary to inject large volumes of local anesthetic--and consequently very high doses--in order to provide an adequate level of block. Subsequent absorption of these high doses, or inadvertent intravenous administration of even small doses, has led to systemic toxicity. Thus, it is desirable to develop adjuvants that are inert alone, but would enhance the potency and/or efficacy of local anesthetics to improve their safety. Adelta/C fibers possess K(+) channels identified as sustained delayed rectifier type K(DR) currents and transient A-type K(A) currents. In the heart, the class III antiarrhythmic drug ibutilide blocks the cardiac component of the rapid delayed rectifying K(+) current (IKr). Experiments were conducted to determine whether co-administration of the K(+) channel blocker ibutilide would enhance the local anesthetic bupivacaine in mice. After injecting bupivacaine mixed with vehicle or ibutilide in the popliteal region of mice, paw withdrawal latencies were determined by applying the plantar aspect of a single hind-paw to the surface a 55 degrees C hot-plate device. 0.5% Bupivacaine+ibutilide (7.8x10(-5) M) elicited significantly longer hot-plate latencies than 0.5% bupivacaine+vehicle. In addition, bupivacaine was 2.6-fold more potent when co-administered with ibutilide rather than vehicle. Epinephrine extends the tissue concentrations of local anesthetics by inducing localized vasoconstriction. Epinephrine augmented the enhancement by ibutilide of bupivacaine's potency by 6.8-fold. In summary, ibutilide may enhance the effects of bupivacaine by blocking K(+) channels on sensory nociceptive nerves.
- Published
- 2007
- Full Text
- View/download PDF
45. Role of kappa and delta opioid receptors in mediating morphine-induced antinociception in morphine-tolerant infant rats.
- Author
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Stoller DC, Sim-Selley LJ, and Smith FL
- Subjects
- Analgesics, Non-Narcotic pharmacology, Animals, Animals, Newborn, Dose-Response Relationship, Drug, Drug Delivery Systems methods, Drug Interactions, Enkephalin, Ala(2)-MePhe(4)-Gly(5)- pharmacology, Female, Guanosine 5'-O-(3-Thiotriphosphate) pharmacokinetics, Naloxone pharmacokinetics, Narcotic Antagonists pharmacology, Pain Measurement methods, Protein Binding drug effects, Rats, Rats, Sprague-Dawley, Reaction Time drug effects, Tritium pharmacokinetics, Drug Tolerance physiology, Morphine administration & dosage, Narcotics administration & dosage, Pain Measurement drug effects, Receptors, Opioid, delta physiology, Receptors, Opioid, kappa physiology
- Abstract
We have previously noted that the antinociceptive efficacy of morphine was significantly decreased in rat pups chronically infused with morphine from implanted osmotic minipumps. In this study, morphine was fully efficacious (i.e., 100% maximum possible effect, %MPE) in the 52 degrees C tail-immersion test after a 72-h infusion from implanted saline-filled osmotic minipumps. However, administration of up to 1000 mg/kg, s.c. morphine failed to elicit greater than a 27% MPE in rats infused with morphine at 2 mg/kg/h. Morphine was more efficacious when the water bath temperature was decreased to 49 degrees C. Experiments were conducted to determine the mechanisms whereby chronic morphine administration leads to a decrease in antinociceptive efficacy. The kappa-opioid antagonist nor-binalorphimine completely blocked the antinociceptive effects of morphine in morphine-infused rat pups. The kappa agonist U50,488 elicited antinociception; however, the requirement to use higher doses in morphine- than saline-infused rats indicates that kappa cross-tolerance was present. Thus, in tolerant rats the antinociceptive effects of high doses of morphine appear to be mediated through kappa-opioid receptors. The delta-opioid antagonist naltrindole was inactive in both treatment groups. DAMGO-stimulated [(35)S]GTPgammaS and [(3)H]naloxone binding reveals that the anatomical distribution of the mu-opioid receptor was consistent with that of the adult rat brain. In adult rats, the mu-opioid receptor is desensitized during morphine tolerance. However, desensitization was not evident in P17 rats based on the lack of significant decreases in [(35)S]GTPgammaS binding. Furthermore, [(3)H]naloxone binding indicated a lack of mu receptor downregulation in morphine-tolerant rat pups.
- Published
- 2007
- Full Text
- View/download PDF
46. Determination of the role of conventional, novel and atypical PKC isoforms in the expression of morphine tolerance in mice.
- Author
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Smith FL, Gabra BH, Smith PA, Redwood MC, and Dewey WL
- Subjects
- Analgesics, Opioid administration & dosage, Animals, Dose-Response Relationship, Drug, Male, Mice, Protein Isoforms metabolism, Drug Tolerance physiology, Morphine administration & dosage, Pain enzymology, Pain prevention & control, Pain Threshold drug effects, Protein Kinase C metabolism
- Abstract
This study comprehensively determines the role of all the major PKC isoforms in the expression morphine tolerance. Pseudosubstrate and receptors for activated C-kinase (RACK) peptides inhibit only a single PKC isoform, while previously tested chemical PKC inhibitors simultaneously inhibit multiple isoforms making it impossible to determine which PKC isoform mediates morphine tolerance. Tolerance can result in a diminished effect during continued exposure to the same amount of substance. In rodents, morphine pellets provide sustained exposures to morphine leading to the development of tolerance by 72 h. We hypothesized that administration of the PKC isoform inhibitors i.c.v. would reverse tolerance and reinstate antinociception in the tail immersion and hot plate tests from the morphine released solely from the pellet. Inhibitors to PKC alpha, gamma and epsilon (100-625 pmol) dose-dependently reinstated antinociception in both tests. The PKC beta(I), beta(II), delta, theta, epsilon, eta and xi inhibitors were inactive (up to 2500 pmol). In other mice, the degree of morphine tolerance was determined by calculating ED50 and potency-ratio values following s.c. morphine administration. Morphine s.c. was 5.6-fold less potent in morphine-pelleted vs. placebo-pelleted mice. Co-administration of s.c. morphine with the inhibitors i.c.v. to either PKC alpha (625 pmol), gamma (100 pmol) or epsilon (400 pmol) completely reversed the tolerance so that s.c. morphine was equally potent in both placebo- and morphine-pelleted mice. The PKC beta(I), beta(II), delta, theta, epsilon, eta and xi inhibitors were inactive. Thus, PKC alpha, gamma and epsilon appear to contribute to the expression of morphine tolerance in mice.
- Published
- 2007
- Full Text
- View/download PDF
47. PKC and PKA inhibitors reinstate morphine-induced behaviors in morphine tolerant mice.
- Author
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Smith FL, Javed RR, Smith PA, Dewey WL, and Gabra BH
- Subjects
- Analgesics, Opioid administration & dosage, Animals, Body Temperature drug effects, Carbazoles pharmacology, Drug Implants, Drug Tolerance, Hot Temperature, Hypothermia chemically induced, Indoles pharmacology, Injections, Intraventricular, Isoquinolines pharmacology, Male, Maleimides pharmacology, Mice, Morphine administration & dosage, Pain psychology, Pyrroles pharmacology, Reaction Time drug effects, Analgesics, Opioid pharmacology, Behavior, Animal drug effects, Cyclic AMP-Dependent Protein Kinases antagonists & inhibitors, Enzyme Inhibitors pharmacology, Morphine pharmacology, Protein Kinase C antagonists & inhibitors
- Abstract
Male Swiss Webster mice exhibited antinociception, hypothermia and Straub tail 3h following a 75mg morphine pellet implantation. These signs disappeared by 72h, and the morphine-pelleted mice were indistinguishable from placebo-pelleted ones, although brain morphine concentrations ranged from 200 to 400ng/gm. We previously demonstrated that chemical inhibitors of protein kinase C (PKC) and A (PKA) are able to reverse morphine tolerance in acutely morphine-challenged mice. However, it was not known whether the reversal of tolerance was due to the interaction of kinase inhibitors with the morphine released from the pellet, the acutely injected morphine to challenge tolerant mice, or both. The present study aimed at determining the interaction between the PKC and PKA inhibitors and the morphine released "solely" from the pellet to reinstate the morphine-induced behavioral and physiological effects, 72h after implantation of morphine pellets. Placebo or 75mg morphine pellets were surgically implanted, and testing was conducted 72h later. Our results showed that the intracerebroventricular (i.c.v.) administration of the PKC inhibitors, bisindolylmaleimide I and Gö-6976 as well as the PKA inhibitors, 4-cyano-3-methylisoquinoline and KT-5720, restored the morphine-induced behaviors of antinociception, Straub tail and hypothermia in morphine-pelleted mice to the same extent observed 3h following the pellet implantation. The tail withdrawal and the hot plate reaction time expressed as percent maximum possible effect (%MPE) was increased to 80-100 and 41-90%, respectively, in PKC and PKA inhibitor-treated morphine tolerant mice compared to 2-10% in non-treated mice. Similarly, a significant hypothermia (1.3-4.0 degrees C decrease in body temperature) was detected in PKC and PKA inhibitor-treated morphine tolerant mice compared to an euthermic state in non-treated morphine tolerant mice. Finally, the Straub tail score was increased to 1.1-1.6 in PKC and PKA inhibitor-treated tolerant mice, whereas it was totally absent in non-treated animals. It is noticeably that the kinase inhibitors used in the study had no effect in placebo-pelleted mice. Our results provide the first evidence on the ability of PKC and PKA inhibitors to reinstate the behavioral and physiological effects of morphine in non-challenged morphine-tolerant animals.
- Published
- 2006
- Full Text
- View/download PDF
48. How important is protein kinase C in mu-opioid receptor desensitization and morphine tolerance?
- Author
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Bailey CP, Smith FL, Kelly E, Dewey WL, and Henderson G
- Subjects
- Animals, Humans, Isoenzymes metabolism, Phosphorylation, Protein Kinase C antagonists & inhibitors, Protein Kinase Inhibitors pharmacology, Receptors, Opioid, mu metabolism, Analgesics, Opioid, Drug Tolerance, Morphine pharmacology, Protein Kinase C metabolism, Receptors, Opioid, mu agonists
- Abstract
The repeated administration of opiate drugs such as morphine results in the development of tolerance to their analgesic, rewarding (euphoric) and respiratory-depressant effects; thus, to obtain the same level of response with subsequent administrations, a greater dose must be used. Tolerance can limit the clinical efficacy of opiate drugs and enhance the social problems that are inherent in recreational opioid abuse. Surprisingly, the mechanism (or mechanisms) underlying the development of morphine tolerance remains controversial. Here, we propose that protein kinase C could have a crucial role in the desensitization of mu-opioid receptors by morphine and that this cellular process could contribute to the development and maintenance of morphine tolerance in vivo.
- Published
- 2006
- Full Text
- View/download PDF
49. Pharmacological characterization of novel water-soluble cannabinoids.
- Author
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Martin BR, Wiley JL, Beletskaya I, Sim-Selley LJ, Smith FL, Dewey WL, Cottney J, Adams J, Baker J, Hill D, Saha B, Zerkowski J, Mahadevan A, and Razdan RK
- Subjects
- Animals, Benzopyrans administration & dosage, Benzopyrans chemistry, Benzopyrans metabolism, Cannabinoids administration & dosage, Cannabinoids chemistry, Cannabinoids metabolism, Cytochrome P-450 Enzyme Inhibitors, Drug Stability, Enzyme Inhibitors pharmacology, Guanosine 5'-O-(3-Thiotriphosphate) metabolism, Humans, Imidazoles administration & dosage, Imidazoles chemistry, Imidazoles metabolism, Male, Mice, Microsomes, Liver metabolism, Receptor, Cannabinoid, CB1 drug effects, Receptor, Cannabinoid, CB1 metabolism, Receptor, Cannabinoid, CB2 drug effects, Receptor, Cannabinoid, CB2 metabolism, Structure-Activity Relationship, Benzopyrans pharmacology, Cannabinoids pharmacology, Imidazoles pharmacology
- Abstract
Presently, there are numerous structural classes of cannabinoid receptor agonists, all of which require solubilization for experimental purposes. One strategy for solubilizing water-insoluble tetrahydrocannabinols is conversion of the phenolic hydroxyl to a morpholinobutyryloxy substituent. The hydrochloride salts of these analogs are water-soluble and active in vivo when administered in saline. The present investigation demonstrated that hydrochloride salts of numerous substituted butyryloxy esters are water-soluble and highly potent. The substitutions include piperidine, piperazine, and alkyl-substituted amino moieties. It was also discovered that incorporation of a nitrogenous moiety in the alkyl side chain increased the pharmacological potency of tetrahydrocannabinol. For example, an analog containing a pyrazole in the side chain (O-2545) was found to have high affinity and efficacy at cannabinoid 1 (CB(1)) and CB(2) receptors, and when dissolved in saline, it was highly efficacious when administered either intravenously or intracerebroventricularly to mice. A series of carboxamido and carboxylic acid amide analogs exhibited high pharmacological potency, but their hydrochloride salts were not water-soluble. On the other hand, incorporation of imidazoles into the terminus of the side chain led to water-soluble hydrochloride salts that were highly potent when administered in saline to laboratory animals. It is now possible to conduct cannabinoid research with agonists that are water-soluble and thus obviating the need of solubilizing agents.
- Published
- 2006
- Full Text
- View/download PDF
50. Enhancement of transdermal fentanyl and buprenorphine antinociception by transdermal delta9-tetrahydrocannabinol.
- Author
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Cichewicz DL, Welch SP, and Smith FL
- Subjects
- Administration, Cutaneous, Analgesics, Non-Narcotic pharmacology, Analgesics, Opioid administration & dosage, Analgesics, Opioid pharmacology, Animals, Buprenorphine pharmacology, Dronabinol pharmacology, Drug Synergism, Female, Fentanyl pharmacology, Guinea Pigs, Analgesics, Non-Narcotic administration & dosage, Buprenorphine administration & dosage, Dronabinol administration & dosage, Fentanyl administration & dosage, Pain Measurement drug effects
- Abstract
Previous studies have demonstrated that delta9-tetrahydrocannabinol (THC) enhances the antinociceptive potency of many opioids administered by a variety of different routes of administration. We hypothesized that THC would enhance fentanyl or buprenorphine analgesia via the transdermal route of administration. THC was first demonstrated to enhance opioid antinociception when both drugs were administered parenterally in a hairless guinea pig model using the pin prick test. A low dose of THC (50 mg/kg, i.p.) produced no antinociception. However, THC enhanced the potency of s.c. fentanyl by 6.7-fold, and s.c. buprenorphine in a non-parallel fashion. For the transdermal studies, THC, fentanyl or buprenorphine was applied by pipette to the skin of the dorsum between the fore- and hind-flanks and covered with individual Tegederm patches. THC (400 mg/kg) produced no antinociception. However, THC enhanced fentanyl's potency by 3.7-fold at 2-h, and 5.8-fold at 4-h. Buprenophine's potency was increased 8.2-fold at 2-h and 7.2-fold at 4-h when co-administered with THC. These results indicate that the enhancement of transdermal opioids by THC could lead to the design of an effective combination analgesic patch.
- Published
- 2005
- Full Text
- View/download PDF
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