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Morshed RA, Cummins DD, Clark JP, Young JS, Haddad AF, Gogos AJ, Hervey-Jumper SL, Berger MS. Asleep triple-modality motor mapping for perirolandic gliomas: an update on outcomes. J Neurosurg 2024; 140:1029-1037. [PMID: 37856395 DOI: 10.3171/2023.8.jns231036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 08/08/2023] [Indexed: 10/21/2023]
Abstract
OBJECTIVE Maximal safe resection of gliomas near motor pathways is facilitated by intraoperative mapping. Here, the authors review their results with triple-modality asleep motor mapping with motor evoked potentials and bipolar and monopolar stimulation for cortical and subcortical mapping during glioma surgery in an expanded cohort. METHODS This was a retrospective analysis of patients who underwent resection of a perirolandic glioma near motor pathways. Clinical and neuromonitoring data were extracted from the electronic medical records for review. All patients with new or worsened postoperative motor deficits were followed for at least 6 months. Regression analyses were performed to assess factors associated with a persistent motor deficit. RESULTS Between January 2018 and December 2021, 160 operations were performed in 151 patients with perirolandic glioma. Sixty-four patients (40%) had preoperative motor deficits, and the median extent of resection was 98%. Overall, patients in 38 cases (23.8%) had new or worse immediate postoperative deficits by discharge, and persistent deficits by 6 months were seen in 6 cases (3.8%), all in patients with high-grade gliomas. There were no new persistent deficits in low-grade glioma patients (0%). The risk factors for a persistent deficit included an insular tumor component (OR 8.6, p = 0.01), preoperative motor weakness (OR 8.1, p = 0.03), intraoperative motor evoked potential (MEP) changes (OR 36.5, p < 0.0001), and peri-resection cavity ischemia (OR 7.5, p = 0.04). Most persistent deficits were attributable to ischemic injury despite structural preservation of the descending motor tracts. For patients with persistent motor deficits, there were 3 cases (50%) in which a change in MEP was noted but subsequent subcortical monopolar stimulation still elicited a response in the corresponding muscle groups, suggesting axonal activation distal to a point of injury. CONCLUSIONS Asleep triple motor mapping results in a low rate of permanent deficits, especially for low-grade gliomas. Peri-resection cavity ischemia continues to be a significant risk factor for permanent deficit despite maintaining appropriate distance for subcortical tracts based on monopolar feedback.
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Affiliation(s)
- Ramin A Morshed
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
| | - Daniel D Cummins
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
| | - John P Clark
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
| | - Jacob S Young
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
| | - Alexander F Haddad
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
| | - Andrew J Gogos
- 2Department of Neurosurgery, St. Vincent's Hospital Melbourne, Victoria, Australia
| | - Shawn L Hervey-Jumper
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
| | - Mitchel S Berger
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
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Ammanuel SG, Kondapavulur S, Lu AY, Breshears JD, Clark JP, Silva AB, Chang EF. Intraoperative cortical stimulation mapping with laryngeal electromyography for the localization of human laryngeal motor cortex. J Neurosurg 2024:1-10. [PMID: 38181494 DOI: 10.3171/2023.10.jns231023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 10/11/2023] [Indexed: 01/07/2024]
Abstract
OBJECTIVE The objectives of this study were to describe the authors' clinical methodology and outcomes for mapping the laryngeal motor cortex (LMC) and define localization of the LMC in a cohort of neurosurgical patients undergoing intraoperative brain mapping. Because of mapping variability across patients, the authors aimed to define the probabilistic distribution of cortical sites that evoke laryngeal movement, as well as adjacent cortical somatotopic representations for the face (mouth), tongue, and hand. METHODS Thirty-six patients underwent left (n = 18) or right (n = 18) craniotomy with asleep motor mapping. For each patient, electromyography (EMG) electrodes were placed in the face, tongue, and hand; a nerve integrity monitor (NIM) endotracheal tube with surface electrodes detected EMG activity from the bilateral vocal folds. After dense cortical stimulation was delivered throughout the sensorimotor cortex, motor responses were then mapped onto a three-dimensional reconstruction of the patient's cortical surfaces for location characterization of the evoked responses. Finally, stimulation sites were transformed into a two-dimensional coordinate system for probabilistic mapping of the stimulation site relative to the central sulcus and sylvian fissure. RESULTS The authors found that the LMC was predominantly localized to a mid precentral gyrus region, dorsal to face representation and surrounding a transverse sulcus ventral to the hand knob. In 14 of 36 patients, the authors identified additional laryngeal responses located ventral to all orofacial representations, providing evidence for dual LMC representations. CONCLUSIONS The authors determined the probabilistic distribution of the LMC. Cortical stimulation mapping with an NIM endotracheal tube is an easy and effective method for mapping the LMC and is simply integrated into the current neuromonitoring methods for brain mapping.
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Affiliation(s)
- Simon G Ammanuel
- 1Department of Neurological Surgery, University of Wisconsin, Madison, Wisconsin
| | | | - Alex Y Lu
- Departments of2Neurological Surgery and
| | - Jonathan D Breshears
- 3Marion Bloch Neuroscience Institute, Saint Luke's Hospital, Kansas City, Missouri; and
| | - John P Clark
- 5Surgical Neurophysiology, University of California, San Francisco, California
| | | | - Edward F Chang
- Departments of2Neurological Surgery and
- 4Center for Integrative Neuroscience, University of California, San Francisco, California
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Nayyar GML, Breman JG, Mackey TK, Clark JP, Hajjou M, Littrell M, Herrington JE. Falsified and Substandard Drugs: Stopping the Pandemic. Am J Trop Med Hyg 2020; 100:1058-1065. [PMID: 30860016 DOI: 10.4269/ajtmh.18-0981] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Falsified and substandard medicines are associated with tens of thousands of deaths, mainly in young children in poor countries. Poor-quality drugs exact an annual economic toll of up to US$200 billion and contribute to the increasing peril of antimicrobial resistance. The WHO has emerged recently as the global leader in the battle against poor-quality drugs, and pharmaceutical companies have increased their roles in assuring the integrity of drug supply chains. Despite advances in drug quality surveillance and detection technology, more efforts are urgently required in research, policy, and field monitoring to halt the pandemic of bad drugs. In addition to strengthening international and national pharmaceutical governance, in part by national implementation of the Model Law on Medicines and Crime, a quantifiable Sustainable Development Goal target and an international convention to insure drug quality and safety are urgent priorities.
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Affiliation(s)
| | - Joel G Breman
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland
| | - Tim K Mackey
- School of Medicine, University of California, San Diego, La Jolla, California
| | - John P Clark
- Pfizer Pharmaceuticals, Pfizer Global Security, New York, New York
| | - Mustapha Hajjou
- Global Health Impact Programs, United States Pharmacopeial Convention, Rockville, Maryland
| | - Megan Littrell
- Public Affairs, Program for Appropriate Technology in Health (PATH), Seattle, Washington
| | - James E Herrington
- Department of Health Behavior, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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Fournier S, Clark JP, Lieberman JA. Letter to the Editor. Incorrect analysis of motor evoked potential efficacy for pedicle subtraction osteotomy. J Neurosurg Spine 2020; 32:1-2. [PMID: 31923891 DOI: 10.3171/2019.8.spine19909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Beever EA, Perrine JD, Rickman T, Flores M, Clark JP, Waters C, Weber SS, Yardley B, Thoma D, Chesley-Preston T, Goehring KE, Magnuson M, Nordensten N, Nelson M, Collins GH. Pika (Ochotona princeps) losses from two isolated regions reflect temperature and water balance, but reflect habitat area in a mainland region. J Mammal 2016. [DOI: 10.1093/jmammal/gyw128] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Clark AJ, Safaee M, Chou D, Weinstein PR, Molinaro AM, Clark JP, Mummaneni PV. Comparative Sensitivity of Intraoperative Motor Evoked Potential Monitoring in Predicting Postoperative Neurologic Deficits: Nondegenerative versus Degenerative Myelopathy. Global Spine J 2016; 6:452-8. [PMID: 27433429 PMCID: PMC4947397 DOI: 10.1055/s-0035-1565258] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 08/24/2015] [Indexed: 11/06/2022] Open
Abstract
STUDY DESIGN Retrospective review. OBJECTIVE Intraoperative motor evoked potential (MEP) monitoring in spine surgery may assist surgeons in taking corrective measures to prevent neurologic deficits. The efficacy of monitoring MEPs intraoperatively in patients with myelopathy from nondegenerative causes has not been quantified. We compared the sensitivity and specificity of intraoperative MEP monitoring in patients with myelopathy caused by nondegenerative processes to patients with degenerative cervicothoracic spondylotic myelopathy (CSM). METHODS We retrospectively reviewed our myelopathy surgical cases during a 1-year period to identify patients with degenerative CSM and CSM of nondegenerative causes and collected data on intraoperative MEP changes and postoperative new deficits. Categorical variables were analyzed by Fisher exact test. Receiver operator curves assessed intraoperative MEP monitoring performance in the two groups. RESULTS In all, 144 patients were identified: 102 had degenerative CSM and 42 had CSM of nondegenerative causes (24 extra-axial tumors, 12 infectious processes, 5 traumatic fractures, and 1 rheumatoid arthritis). For degenerative CSM, there were 11 intraoperative MEP alerts and 7 new deficits (p < 0.001). The corresponding sensitivity was 71% and the specificity was 94%. In the nondegenerative group, there were 11 intraoperative MEP alerts and 3 deficits, which was not significant (p > 0.99). The sensitivity (33%) and specificity (74%) were lower. Among patients with degenerative CSM, the model performed well for predicting postoperative deficits (area under the curve [AUC] 0.826), which appeared better than the nondegenerative group, although it did not reach statistical significance (AUC 0.538, p = 0.16). CONCLUSIONS Based on this large retrospective analysis, intraoperative MEP monitoring in surgery for nondegenerative CSM cases appears to be less sensitive to cord injury and less predictive of postoperative deficits when compared with degenerative CSM cases.
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Affiliation(s)
- Aaron J. Clark
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, California, United States
| | - Michael Safaee
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, California, United States
| | - Dean Chou
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, California, United States
| | - Philip R. Weinstein
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, California, United States
| | - Annette M. Molinaro
- Departments of Neurological Surgery and Epidemiology and Biostatistics, University of California, San Francisco, California, United States
| | - John P. Clark
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, California, United States
| | - Praveen V. Mummaneni
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, California, United States,Address for correspondence Praveen V. Mummaneni, MD Department of Neurological Surgery, University of California505 Parnassus Avenue, Room M779, San Francisco, CA 94143-0112United States
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Nayyar GML, Attaran A, Clark JP, Culzoni MJ, Fernandez FM, Herrington JE, Kendall M, Newton PN, Breman JG. Responding to the pandemic of falsified medicines. Am J Trop Med Hyg 2015; 92:113-118. [PMID: 25897060 PMCID: PMC4455086 DOI: 10.4269/ajtmh.14-0393] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 03/25/2015] [Indexed: 11/30/2022] Open
Abstract
Over the past decade, the number of countries reporting falsified (fake, spurious/falsely labeled/counterfeit) medicines and the types and quantities of fraudulent drugs being distributed have increased greatly. The obstacles in combating falsified pharmaceuticals include 1) lack of consensus on definitions, 2) paucity of reliable and scalable technology to detect fakes before they reach patients, 3) poor global and national leadership and accountability systems for combating this scourge, and 4) deficient manufacturing and regulatory challenges, especially in China and India where fake products often originate. The major needs to improve the quality of the world's medicines fall into three main areas: 1) research to develop and compare accurate and affordable tools to identify high-quality drugs at all levels of distribution; 2) an international convention and national legislation to facilitate production and utilization of high-quality drugs and protect all countries from the criminal and the negligent who make, distribute, and sell life-threatening products; and 3) a highly qualified, well-supported international science and public health organization that will establish standards, drug-quality surveillance, and training programs like the U.S. Food and Drug Administration. Such leadership would give authoritative guidance for countries in cooperation with national medical regulatory agencies, pharmaceutical companies, and international agencies, all of which have an urgent interest and investment in ensuring that patients throughout the world have access to good quality medicines. The organization would also advocate strongly for including targets for achieving good quality medicines in the United Nations Millennium Development Goals and Sustainable Development Goals.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Joel G. Breman
- *Address correspondence to Joel G. Breman, Fogarty International Center, National Institutes of Health, 16 Center Drive, Bethesda, MD 20892. E-mail:
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Clark AJ, Ziewacz JE, Safaee M, Lau D, Lyon R, Chou D, Weinstein PR, Ames CP, Clark JP, Mummaneni PV. Intraoperative neuromonitoring with MEPs and prediction of postoperative neurological deficits in patients undergoing surgery for cervical and cervicothoracic myelopathy. Neurosurg Focus 2014; 35:E7. [PMID: 23815252 DOI: 10.3171/2013.4.focus13121] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The use of intraoperative neurophysiological monitoring (IONM) in surgical decompression surgery for myelopathy may assist the surgeon in taking corrective measures to reduce or prevent permanent neurological deficits. We evaluated the efficacy of IONM in cervical and cervicothoracic spondylotic myelopathy (CSM) cases. METHODS The authors retrospectively reviewed 140 cases involving patients who underwent surgery for CSM utilizing IONM during 2011 at the University of California, San Francisco. Data on preoperative clinical variables, intraoperative changes in transcranial motor evoked potentials (MEPs), and postoperative new neurological deficits were collected. Associations between categorical variables were analyzed with the Fisher exact test. RESULTS Of the 140 patients, 16 (11%) had significant intraoperative decreases in MEPs. In 8 of these cases, the MEP signal did not return to baseline values by the end of the operation. There were 8 (6%) postoperative deficits, of which 6 were C-5 palsies and 2 were paraparesis. Six of the patients with postoperative deficits had demonstrated persistent MEP signal change on IONM. There was a significant association between persistent MEP changes and postoperative deficits (p < 0.001). The sensitivity of intraoperative MEP monitoring was 75%, the specificity 98%, the positive predictive value 75%, and the negative predictive value 98%. Due to higher rates of false negatives, the sensitivity decreased to 60% in the subgroup of patients with vascular disease comorbidity. The sensitivity increased to 100% in elderly patients and in patients with preoperative motor deficits. The sensitivity and positive predictive value of deltoid and biceps MEP changes in predicting C-5 palsy were 67% and 67%, respectively. CONCLUSIONS The authors found a correlation between decreased intraoperative MEPs and postoperative new neurological deficits in patients with CSM. Sensitivity varies based on patient comorbidities, age, and preoperative neurological function. Monitoring of MEPs is a useful adjunct for CSM cases, and the authors have developed a checklist to standardize their responses to intraoperative MEP changes.
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Affiliation(s)
- Aaron J Clark
- Department of Neurological Surgery, University of California, San Francisco, California 94143-0112, USA
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Merson S, Yang ZH, Brewer D, Olmos D, Eichholz A, McCarthy F, Fisher G, Kovacs G, Berney DM, Foster CS, Møller H, Scardino P, Cuzick J, Cooper CS, Clark JP. Focal amplification of the androgen receptor gene in hormone-naive human prostate cancer. Br J Cancer 2014; 110:1655-62. [PMID: 24481405 PMCID: PMC3960602 DOI: 10.1038/bjc.2014.13] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 12/18/2013] [Accepted: 12/19/2013] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Androgen receptor (AR)-gene amplification, found in 20-30% of castration-resistant prostate cancer (CRPCa) is proposed to develop as a consequence of hormone-deprivation therapy and be a prime cause of treatment failure. Here we investigate AR-gene amplification in cancers before hormone deprivation therapy. METHODS A tissue microarray (TMA) series of 596 hormone-naive prostate cancers (HNPCas) was screened for chromosome X and AR-gene locus-specific copy number alterations using four-colour fluorescence in situ hybridisation. RESULTS Both high level gain in chromosome X (≥4 fold; n=4, 0.7%) and locus-specific amplification of the AR-gene (n=6, 1%) were detected at low frequencies in HNPCa TMAs. Fluorescence in situ hybridisation mapping whole sections taken from the original HNPCa specimen blocks demonstrated that AR-gene amplifications exist in small foci of cells (≤ 600 nm, ≤1% of tumour volume). Patients with AR gene-locus-specific copy number gains had poorer prostate cancer-specific survival. CONCLUSION Small clonal foci of cancer containing high level gain of the androgen receptor (AR)-gene develop before hormone deprivation therapy. Their small size makes detection by TMA inefficient and suggests a higher prevalence than that reported herein. It is hypothesised that a large proportion of AR-amplified CRPCa could pre-date hormone deprivation therapy and that these patients would potentially benefit from early total androgen ablation.
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Affiliation(s)
- S Merson
- Molecular Carcinogenesis, Institute of Cancer Research, Male Urological Cancer Research Centre, Surrey, UK
| | - Z H Yang
- The Centre for Cancer Prevention, Wolfson Institute of Preventive Medicine, St Bartholomew's Medical School, Queen Mary, University of London, London, UK
| | - D Brewer
- 1] Molecular Carcinogenesis, Institute of Cancer Research, Male Urological Cancer Research Centre, Surrey, UK [2] Department of Cancer Genetics, University of East Anglia, Norwich, UK
| | - D Olmos
- Prostate Cancer Research, Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro, 28029 Madrid, Spain
| | - A Eichholz
- Molecular Carcinogenesis, Institute of Cancer Research, Male Urological Cancer Research Centre, Surrey, UK
| | - F McCarthy
- Molecular Carcinogenesis, Institute of Cancer Research, Male Urological Cancer Research Centre, Surrey, UK
| | - G Fisher
- The Centre for Cancer Prevention, Wolfson Institute of Preventive Medicine, St Bartholomew's Medical School, Queen Mary, University of London, London, UK
| | - G Kovacs
- Laboratory of Molecular Oncology, Medical Faculty, Ruprecht-Karls-Universitat, Heidelberg, Germany
| | - D M Berney
- Department of Molecular Oncology, Barts Cancer Institute, Charterhouse Square, London, UK
| | - C S Foster
- Molecular Pathology Laboratory, Liverpool University, Liverpool, UK and HCA Laboratories, London, UK
| | - H Møller
- 1] The Centre for Cancer Prevention, Wolfson Institute of Preventive Medicine, St Bartholomew's Medical School, Queen Mary, University of London, London, UK [2] King's College London, Cancer Epidemiology and Population Health, London, UK
| | - P Scardino
- Department of Urology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - J Cuzick
- The Centre for Cancer Prevention, Wolfson Institute of Preventive Medicine, St Bartholomew's Medical School, Queen Mary, University of London, London, UK
| | - C S Cooper
- Department of Cancer Genetics, University of East Anglia, Norwich, UK
| | - J P Clark
- Department of Cancer Genetics, University of East Anglia, Norwich, UK
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Campbell N, Clark JP, Stecher VJ, Thomas JW, Callanan AC, Donnelly BF, Goldstein I, Kaminetsky JC. Adulteration of purported herbal and natural sexual performance enhancement dietary supplements with synthetic phosphodiesterase type 5 inhibitors. J Sex Med 2013; 10:1842-9. [PMID: 23634714 DOI: 10.1111/jsm.12172] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Many products labeled "herbal" or "all natural" (herbal/natural) that claim to enhance sexual performance and imply use for the treatment of erectile dysfunction (ED) are marketed as over-the-counter (OTC) dietary supplements. However, adulteration with undeclared phosphodiesterase type 5 (PDE5) inhibitors appears widespread. AIM To assess the availability, cost, origin, categorical content, and adulteration with PDE5 inhibitors of purported herbal/natural OTC dietary supplements claiming to naturally enhance sexual performance. METHODS Pfizer Global Security coordinated sample collection (all from convenience stores and filling stations in two U.S. metropolitan areas except for seven from U.S. Customs seizures) and liquid chromatography/mass spectrometry examination. MAIN OUTCOME MEASURE Adulteration with synthetic PDE5 inhibitors. RESULTS Ninety-one samples labeled as 58 distinct products and priced from $2.99 to $17.99 were evaluated. Origin/manufacture was claimed as United States (n = 62), apparently Asian (n = 15), and not clearly identified (n = 14). Although no sample claimed to include synthetic substances, 74 (81%) contained PDE5-inhibitor pharmaceutical ingredients, including tadalafil and/or sildenafil (n = 40, of which 18 contained >110% of the highest approved drug product strength) or PDE5-inhibitor analogs (n = 34). Pronounced heterogeneity of contents between samples within individual products indicated minimal quality control during manufacture. Labeling was inadequate (e.g., lacking lot number and/or expiry date) for 17 products (23 samples) and inconsistent between samples within a given product (e.g., in manufacturer, lot number, and/or expiry date) for seven of 17 products having multiple samples. Only 14 samples warned against concomitant nitrate use. CONCLUSIONS Ethical pharmaceutical companies are concerned for an unsuspecting public when their products are counterfeited, mislabeled, and illegally offered for sale in an unsafe manner. Because of the dangers of adulteration with synthetic PDE5 inhibitors, absent safety warnings, and lack of quality or consistent manufacture, men with ED unknowingly risk their health by using OTC herbal/natural products that claim to enhance sexual performance.
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Warren DE, Bickler PE, Clark JP, Gregersen M, Brosnan H, McKleroy W, Gabatto P. Hypothermia and rewarming injury in hippocampal neurons involve intracellular Ca2+ and glutamate excitotoxicity. Neuroscience 2012; 207:316-25. [PMID: 22265728 DOI: 10.1016/j.neuroscience.2011.12.034] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 12/16/2011] [Accepted: 12/19/2011] [Indexed: 11/18/2022]
Abstract
This study examines the causes of hypothermia and rewarming injury in CA1, CA3, and dentate neurons in rat hippocampal slice cultures. Neuronal death, assessed with propidium iodide or Sytox fluorescence, Fluoro-Jade labeling, and Cresyl Violet staining, depended on the severity and duration of hypothermia. More than 6 h at temperatures less than 12 °C followed by rewarming to 37 °C (profound hypothermia and rewarming, PH/RW) caused swelling and death in large number of neurons in CA1, CA3, and dentate. During PH, [ATP] decreased and [Ca(2+)](I) and extracellular [glutamate] increased, with neuron rupture and nuclear condensation following RW. The data support the hypothesis that neuronal death from PH/RW is excitotoxic, due to ATP loss, glutamate receptor activation and Ca(2+) influx. We found that antagonism of N-methyl-D-aspartate (NMDA) receptors, but not 2-amino-3-(5-methyl-3-oxo-1,2- oxazol-4-yl) propanoic acid or metabotropic glutamate receptors, decreased neuron death and prevented increases in [Ca(2+)](I) caused by PH/RW. Chelating extracellular Ca(2+) decreased PH/RW injury, but inhibiting L- and T-type voltage-gated Ca(2+) channels, K+ channels, Ca(2+) release from the endoplasmic reticulum, and reverse Na(+)/Ca(2+) exchange did not affect the Ca(2+) changes or cell death. We conclude that the mechanism of PH/RW neuronal injury in hippocampal slices primarily involves intracellular Ca(2+) accumulation mediated by NMDA receptors that activates necrotic, but not apoptotic processes.
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Affiliation(s)
- D E Warren
- Department of Anesthesia and Perioperative Care, Parnassus Avenue, University of California, San Francisco, CA 94143-0542, USA
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Fu Y, Westenbroek RE, Yu FH, Clark JP, Marshall MR, Scheuer T, Catterall WA. Deletion of the distal C terminus of CaV1.2 channels leads to loss of beta-adrenergic regulation and heart failure in vivo. J Biol Chem 2011; 286:12617-26. [PMID: 21216955 DOI: 10.1074/jbc.m110.175307] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
L-type calcium currents conducted by CaV1.2 channels initiate excitation-contraction coupling in cardiac and vascular smooth muscle. In the heart, the distal portion of the C terminus (DCT) is proteolytically processed in vivo and serves as a noncovalently associated autoinhibitor of CaV1.2 channel activity. This autoinhibitory complex, with A-kinase anchoring protein-15 (AKAP15) bound to the DCT, is hypothesized to serve as the substrate for β-adrenergic regulation in the fight-or-flight response. Mice expressing CaV1.2 channels with the distal C terminus deleted (DCT-/-) develop cardiac hypertrophy and die prematurely after E15. Cardiac hypertrophy and survival rate were improved by drug treatments that reduce peripheral vascular resistance and hypertension, consistent with the hypothesis that CaV1.2 hyperactivity in vascular smooth muscle causes hypertension, hypertrophy, and premature death. However, in contrast to expectation, L-type Ca2+ currents in cardiac myocytes from DCT-/- mice were dramatically reduced due to decreased cell-surface expression of CaV1.2 protein, and the voltage dependence of activation and the kinetics of inactivation were altered. CaV1.2 channels in DCT-/- myocytes fail to respond to activation of adenylyl cyclase by forskolin, and the localized expression of AKAP15 is reduced. Therefore, we conclude that the DCT of CaV1.2 channels is required in vivo for normal vascular regulation, cell-surface expression of CaV1.2 channels in cardiac myocytes, and β-adrenergic stimulation of L-type Ca2+ currents in the heart.
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Affiliation(s)
- Ying Fu
- Department of Pharmacology, University of Washington, Seattle, Washington 98195-7280, USA
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Abstract
The circadian pacemaker within the suprachiasmatic nucleus (SCN) confers daily rhythms to bodily functions. In nature, the circadian clock will adopt a 24-h period by synchronizing to the solar light/dark cycle. This light entrainment process is mediated, in part, at glutamatergic synapses formed between retinal ganglion afferents and SCN neurons. N-methyl-D-aspartate receptors (NMDARs) located on SCN neurons gate light-induced phase resetting. Despite their importance in circadian physiology, little is known about their functional stoichiometry. We investigated the NR2-subunit composition with whole cell recordings of SCN neurons within the murine hypothalamic brain slice using a combination of subtype-selective NMDAR antagonists and voltage-clamp protocols. We found that extracellular magnesium ([Mg](o)) strongly blocks SCN NMDARs exhibiting affinities and voltage sensitivities associated with NR2A and NR2B subunits. These NMDAR currents were inhibited strongly by NR2B-selective antagonists, Ro 25-6981 (3.5 microM, 55.0 +/- 9.0% block; mean +/- SE) and ifenprodil (10 microM, 55.8 +/- 3.0% block). The current remaining showed decreased [Mg](o) affinities reminiscent of NR2C and NR2D subunits but was highly sensitive to [Zn](o), a potent NR2A blocker, showing a approximately 44.2 +/- 1.1% maximal inhibition at saturating concentrations with an IC(50) of 7.8 +/- 1.1 nM. Considering the selectivity, efficacy, and potency of the drugs used in combination with [Mg](o)-block characteristics of the NMDAR, our data show that both diheteromeric NR2B NMDARs and triheteromeric NR2A NMDARs (paired with an NR2C or NR2D subunits) account for the vast majority of the NMDAR current within the SCN.
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Affiliation(s)
- J P Clark
- Department of Neuroscience, University of Minnesota, 6-145 Jackson Hall, 321 Church St. SE, Minneapolis, MN 55455, USA
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Clark JP, Sampair CS, Kofuji P, Nath A, Ding JM. HIV protein, transactivator of transcription, alters circadian rhythms through the light entrainment pathway. Am J Physiol Regul Integr Comp Physiol 2005; 289:R656-62. [PMID: 15860648 DOI: 10.1152/ajpregu.00179.2005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Patients infected with the human immunodeficiency virus (HIV), and other mammals infected with related lentiviruses, exhibit fatigue, altered sleep patterns, and abnormal circadian rhythms. A circadian clock in the hypothalamic suprachiasmatic nucleus (SCN) temporally regulates these functions in mammals. We found that a secretary HIV transcription factor, transactivator of transcription (Tat), resets the murine circadian clock, in vitro and in vivo, at clinically relevant concentrations (EC50= 0.31 nM). This effect of Tat occurs only during the subjective night, when N-methyl-d-aspartate (NMDA) receptor [d-2-amino-5-phosphonovaleric acid (0.1 mM)] and nitric oxide synthase ( NG-nitro-l-arginine methyl ester, 0.1 mM) inhibitors block Tat-induced phase shifts. Whole cell recordings of SCN neurons within the brain slice revealed that Tat did not activate NMDA receptors directly but potentiated NMDA receptor currents through the enhancement of glutamate release. Consistent with this presynaptic mechanism, inhibitors of neurotransmission block Tat-induced phase shifts, such as tetrodotoxin (1 μM), tetanus toxin (1 μM), P/Q/N type-calcium channel blockers (1 μM ω-agatoxin IVA and 1 μM ω-conotoxin GIVA) and bafilomycin A1(1 μM). Thus the effect of Tat on the SCN may underlie lentiviral circadian rhythm dysfunction by operating as a disease-dependent modulator of light entrainment through the enhancement of excitatory neurotransmission.
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Affiliation(s)
- J P Clark
- Dept. of Physiology, Brody School of Medicine, East Carolina University, 600 Moye Blvd., Greenville, NC 27858, USA
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Abstract
The health and safety of women who work as exotic dancers are firmly embedded within the social organization of the strip club and the broader social, economic and political context of the work of exotic dancing. Exotic dancers in this study expressed health concerns associated with: the effects of costuming and appearance requirements; dirty work environments; problems due to stigmatization, sexual harassment and assault; and police disinterest or victim blaming. The balance between benefits and hazards related to exotic dancing is influenced not only by the personal choices made by dancers, but also by the organization of the strip club and the broader context within which exotic dancing takes place.
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Affiliation(s)
- E Maticka-Tyndale
- Department of Sociology and Anthropology, University of Windsor, Ontario, Canada
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Rochon PA, Tu JV, Anderson GM, Gurwitz JH, Clark JP, Lau P, Szalai JP, Sykora K, Naylor CD. Rate of heart failure and 1-year survival for older people receiving low-dose beta-blocker therapy after myocardial infarction. Lancet 2000; 356:639-44. [PMID: 10968437 DOI: 10.1016/s0140-6736(00)02606-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Many older people do not receive beta-blocker therapy after myocardial infarction or receive doses lower than those tested in trials, perhaps because physicians fear that beta-blockers may precipitate heart failure. We examined the relation between use of beta-blockers, the dose used, and hospital admission for heart failure and 1-year survival in a cohort of all older patients surviving myocardial infarction in Ontario, Canada. METHODS We collected data on a cohort of 13,623 patients aged 66 years or older who were discharged from hospital after a myocardial infarction and who did not receive beta-blocker therapy or received low, standard, or high doses. We used Cox's proportional-hazards models to study the association of dose with admission for heart failure and survival with adjustment for factors including age, sex, and comorbidity. FINDINGS Among 8232 patients with no previous history of heart failure, dispensing of beta-blocker therapy was associated with a 43% reduction in subsequent admission for heart failure (adjusted risk ratio 0.57 [95% CI 0.48-0.69]) compared with patients not dispensed this therapy. Among the 4681 patients prescribed beta-blockers, the risk of admission was greater in the high-dose than in the low-dose group (1.53 [1.01-2.31]). Among all 13,623 patients in the cohort, 2326 (17.1%) died by 1 year. Compared with those not dispensed beta-blocker therapy, the adjusted risk ratio for mortality was lower for all three doses (low 0.40 [0.34-0.47], standard 0.36 [0.31-0.42], high 0.43 [0.33-0.56]). INTERPRETATION Compared with high-dose beta-blocker therapy, low-dose treatment is associated with a lower rate of hospital admission for heart failure and has a similar 1-year survival benefit. Our findings support the need for a randomised controlled trial comparing doses of beta-blocker therapy in elderly patients.
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Affiliation(s)
- P A Rochon
- Kunin-Lunenfeld Applied Research Unit, Baycrest Centre for Geriatric Care, University of Toronto, Ontario, Canada
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Abstract
OBJECTIVE To determine the representation of the sexes in JAMA cover art. DESIGN Review of 50 consecutive issues. SETTING JAMA, March 1997-March 1998. MAIN OUTCOME MEASURES Numbers and nature of covers portraying men and women. RESULTS Of the 50 covers, 34 depicted humans. 15 depicted women, 13 men, and 6 were of mixed or indeterminate sex. 11 pictures of women included a child and five included nudity. One cover showed a man with a child (not as a father) and none depicted nudity. Men were depicted exclusively in authoritative roles. CONCLUSIONS Much of the cover art gives strong messages about sexual stereotypes that are inappropriate in modern society. JAMA should consider reviewing its policy for choosing cover art.
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Affiliation(s)
- J P Clark
- Department of Public Health Sciences, University of Toronto, Canada.
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Rochon PA, Anderson GM, Tu JV, Clark JP, Gurwitz JH, Szalai JP, Lau P. Use of beta-blocker therapy in older patients after acute myocardial infarction in Ontario. CMAJ 1999; 161:1403-8. [PMID: 10906894 PMCID: PMC1230828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
BACKGROUND Despite its proven efficacy, beta-blocker therapy remains underused in elderly patients after myocardial infarction (MI). The objectives of this study were to identify undertreated groups of seniors and to determine whether older and frailer patients are being selectively dispensed low-dose beta-blocker therapy. METHODS From a comprehensive hospital discharge database, all people aged 66 years or more in Ontario who survived an acute MI between April 1993 and March 1995 were identified and classified into those who did not receive beta-blocker therapy and those dispensed low, standard or high doses of this agent. Logistic regression models were used to study the effect of age, sex, comorbidity, potential contraindications to beta-blocker therapy and residence in a long-term-care facility on the odds of not being dispensed a beta-blocker. Among beta-blocker users, the odds of being dispensed low relative to standard or high doses of this agent were evaluated. RESULTS Of the 15,542 patients, 7549 (48.6%) were not dispensed a beta-blocker. Patients 85 years of age or more were at greater risk of not receiving beta-blocker therapy (adjusted odds ratio [OR] 2.8, 95% confidence interval [CI] 2.5-3.2) than were those 66 to 74 years. Having a Charlson comorbidity index of 3 or greater was associated with an increased risk of not receiving beta-blocker therapy (adjusted OR 1.5, 95% CI 1.3-1.8) compared with having lower comorbidity scores. Patients who resided in a long-term-care facility were at increased risk of not being prescribed beta-blocker therapy (adjusted OR 2.6, 95% CI 2.0-3.4). Among the 5453 patients with no identifiable contraindication to beta-blocker therapy, women were significantly less likely than men to receive this agent (p = 0.005). Of the 6074 patients who received beta-blockers, 2248 (37.0%) were dispensed low-dose therapy. Patients aged 85 years or more had an increased risk of being dispensed low-dose therapy (adjusted OR 1.6, 95% CI 1.3-2.0) compared with those aged 66 to 74 years. Compared with those who had the lowest comorbidity scores, patients with the highest comorbidity scores were more likely to be dispensed low-dose beta-blocker therapy (adjusted OR 1.3, 95% CI 1.0-1.8). INTERPRETATION Almost half of Ontario patients aged 66 or more who survived an MI, particularly those who were older or frailer, did not receive beta-blocker therapy. Among those dispensed beta-blocker therapy, older and frailer patients were more frequently dispensed low-dose therapy.
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Affiliation(s)
- P A Rochon
- Kunin-Lunenfeld Applied Research Unit, Baycrest Centre for Geriatric Care, Toronto, Ont.
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Rochon PA, Anderson GM, Tu JV, Gurwitz JH, Clark JP, Shear NH, Lau P. Age- and gender-related use of low-dose drug therapy: the need to manufacture low-dose therapy and evaluate the minimum effective dose. J Am Geriatr Soc 1999; 47:954-9. [PMID: 10443856 DOI: 10.1111/j.1532-5415.1999.tb01290.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Low-dose drug therapy is promoted as a way to maximize benefit and minimize adverse drug effects when prescribing for older adults. This population-based study evaluates the age and sex-related use of two common therapies: thiazide diuretics, where evidence supports the use of low-dose therapy, and beta-blockers, where trials have not evaluated the minimum effective dose. DESIGN Using linked administrative databases we identified all of the 120,613 persons dispensed a thiazide diuretic therapy and 12,908 myocardial infarction survivors dispensed beta-blocker therapy in Canada's largest province. We used logistic regression models to study the association of age and sex with dispensing of low-dose thiazide diuretic and beta-blocker therapy at doses lower than evaluated in trials. RESULTS Of 120,613 older people dispensed a thiazide diuretic, 32,372 (26.8%) were dispensed a low dose. Patients 85 years of age or older, relative to the youngest group, were 30% more likely to be dispensed low-dose therapy (OR=1.31; 95% CI, 1.27 to 1.36; P < .001). Women were 8% more likely than men to be dispensed a low-dose thiazide diuretic (OR=1.08; 95% CI, 1.05 to 1.11; P < .001). Of 10,991 myocardial infarction survivors dispensed atenolol, metoprolol, propranolol, or timolol, 9458 (86.1%) were dispensed a lower-than-evaluated dose. Patients 85 years of age or older, relative to those in the youngest group, were more than twice as likely to be dispensed a lower-than-evaluated beta-blocker therapy dose (OR=2.28; 95% CI, 1.74 to 3.04; P < .001). No difference was noted in the use of beta-blocker therapy dose by sex (OR=1.0; 95% CI, .89 to 1.15; P = .95). CONCLUSIONS Low-dose thiazide diuretic therapy prescribed widely to older people, particularly those of advanced age and women. The vast majority of myocardial infarction survivors were dispensed beta-blocker therapy at lower-than-evaluated doses. These findings highlight the need to manufacture low-dose thiazide diuretic therapy and to evaluate the minimum effective dose of beta-blocker therapy.
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Affiliation(s)
- P A Rochon
- Kunin-Lunenfeld Applied Research Unit, Baycrest Centre for Geriatric Care, University of Toronto, Ontario, Canada
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Maticka-Tyndale E, Lewis J, Clark JP, Zubick J, Young S. Social and cultural vulnerability to sexually transmitted infection: the work of exotic dancers. Can J Public Health 1999. [PMID: 10189733 DOI: 10.1007/bf03404092] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This article examines the social and cultural factors that influence the vulnerability of female exotic dancers to sexually transmitted infections. Results are based on a qualitative, exploratory study using observations in 10 clubs and in-depth interviews with 30 dancers in southern Ontario. The social and cultural context within which exotic dancing takes place contributes to a chronic state of sexual harassment and sexual assault in the strip clubs. Women are pressured by economics and by their customers to engage in sex for pay. The defence mechanisms that some women use to deal with these work conditions also contribute to women's vulnerability. The social structure of strip clubs and their policies toward employees and customers can either reduce or exacerbate the vulnerability of dancers. Workplace policies and health and safety standards appear to be the most effective ways to decrease the vulnerability of dancers. Public health units can work with employers and dancers to establish workplace policies and programmes that contribute to the health and wellbeing of dancers.
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Rochon PA, Clark JP, Gurwitz JH. Challenges of prescribing low-dose drug therapy for older people. CMAJ 1999; 160:1029-31. [PMID: 10207345 PMCID: PMC1230198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Affiliation(s)
- P A Rochon
- Kunin-Lunenfeld Applied Research Unit, Baycrest Centre for Geriatric Care, Toronto, Ont
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Luo J, Cheung J, Yevich EM, Clark JP, Tsai J, Lapresca P, Ubillas RP, Fort DM, Carlson TJ, Hector RF, King SR, Mendez CD, Jolad SD, Reaven GM. Novel terpenoid-type quinones isolated from Pycnanthus angolensis of potential utility in the treatment of type 2 diabetes. J Pharmacol Exp Ther 1999; 288:529-34. [PMID: 9918555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
Abstract
Using an ethnomedical-based drug discovery program, two previously unknown compounds (SP-18904 and SP-18905) from Pycnanthus angolensis were isolated that lower glucose concentrations in mouse models of type 2 diabetes. SP-18904 and SP-18905 are terpenoid-type quinones that significantly lowered plasma glucose concentration (p <.05) when given orally to either ob/ob or db/db mice, both of which are hyperglycemic and hyperinsulinemic. The antihyperglycemic actions of SP-18904 and SP-18905 were associated with significant decreases in plasma insulin concentrations (p <.05), suggesting that both compounds lowered glucose by enhancing insulin-mediated glucose uptake. This was supported by the insulin suppression test in ob/ob mice. Studies in hyperglycemic, insulin-deficient mice and in vitro experiments on 3T3-L1 adipocytes further supported this conclusion. As such, these two terpenoid-type quinones represent a new class of compounds of potential use in the treatment of type 2 diabetes.
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Affiliation(s)
- J Luo
- Shaman Pharmaceuticals, Inc., South San Francisco, California 94080- 4812, USA
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Rochon PA, Clark JP, Binns MA, Patel V, Gurwitz JH. Reporting of gender-related information in clinical trials of drug therapy for myocardial infarction. CMAJ 1998; 159:321-7. [PMID: 9732709 PMCID: PMC1229590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Concern has been expressed that women are not adequately represented in clinical trials evaluating treatments for medical conditions they commonly experience. This study was designed to assess the reporting of data on women in recently published trials of drug therapy for myocardial infarction, including those funded by an agency with a gender-related policy. METHODS All randomized controlled trials and meta-analyses of drug therapies for myocardial infarction published in The New England Journal of Medicine, The Lancet, The Journal of the American Medical Association, the Annals of Internal Medicine and the British Medical Journal from January 1992 to December 1996 were evaluated. On preliminary review 102 articles met the inclusion criteria; these were reviewed in detail, and 59 were excluded. Two reviewers independently extracted gender-related information from the 43 articles; discrepancies were resolved by consensus. RESULTS Women presented up to 48% of the trial participants (mean 24.1%). In the trials funded by an agency with a gender-related policy, only 16.8% of participants, on average, were women. Of the 43 articles in the sample, only 14 (32%) provided gender-related results. Funding from an agency with gender-related policy did not affect the reporting of gender-related information. Subgroup analyses were provided for 14 (32%) of the 43 trials, including 2 (29%) of 7 trials funded by an agency with a gender-related policy. Of the 12 trials that included interaction analyses (excluding the 2 trials in which secondary analyses were conducted specifically to identify differences between women and men), 7 (58%) conducted an interaction analysis to determine if women responded differently than men; for one of these the interaction analysis was for a secondary outcome measure (drug safety). Only 5 (12%) of the 43 articles mentioned the differences between men and women in the Discussion section; 2 of these were studies that used secondary analyses to examine sex differences. Of the 5, only 1 was funded by an agency with a gender-related policy. INTERPRETATION Women were poorly represented in the randomized controlled trials in this sample, regardless of whether the trials were funded by an agency with a gender-related policy. Structured reporting of gender-related information for clinical trials may improve the quality of information available about women and therefore facilitate the application of research findings to the care of women.
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Affiliation(s)
- P A Rochon
- Kunin-Lunenfeld Applied Research Unit, Baycrest Centre for Geriatric Care, Toronto, Ont.
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Rardin KD, Gillespie WJ, Clark JP, Strachan R, Golden R. Document imaging: defining its role. Healthc Inform 1996; 13:76-9, 81. [PMID: 10155769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Clark JP. Non-profits in cyberspace: the fund raiser's guide. Fund Raising Manage 1995; 26:28, 30-2. [PMID: 10151832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Warren W, Clark JP, Gardner E, Harris G, Cooper CS, Lawley PD. Chemical induction of thymomas in AKR mice: interaction of chemical carcinogens and endogenous murine leukemia viruses. Comparison of N-methyl-N-nitrosourea and methyl methanesulphonate. Mol Carcinog 1990; 3:126-33. [PMID: 2164817 DOI: 10.1002/mc.2940030305] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The time course of development of thymic lymphoma, which occurs spontaneously in mice of the AKR strain, is accelerated by the methylating agents N-methyl-N-nitrosourea (MNU) and methyl methanesulphonate (MMS). Since MNU is a potent mutagen inducing G----A transition mutations and MMS a relatively weak mutagen, it was of interest to examine the genetic alterations associated with each class of the chemically induced tumors and to compare these alterations with those found in the spontaneous tumors. The same spectrum of genetic alterations was found for MMS-induced and spontaneous thymomas. Both showed rearrangements of c-myc and Pim-1 genes that appeared to result from integration of recombinant mink cytopathic focus-forming (MCF) proviruses but failed to reveal evidence for activation of ras oncogenes, either by DNA transfection experiments or by hybridization of DNA to specific oligonucleotide probes. Some alteration in c-myc and Pim-1 genes were also found in MNU-induced tumors, but, mainly, these involved integration of ecotropic-like rather than recombinant MCF viruses. Furthermore, MNU-induced tumors frequently (in 24% of thymomas) contained G----A transition mutations, activating the Ki-ras oncogene at codon 12 position 2. Another feature that distinguishes the MNU-induced tumors from those occurring in untreated and MMS-treated mice was the consistently high level of c-myc mRNA that occurred in the absence of c-myc gene rearrangement. Taken together, the data indicate that the mechanisms of development of tumors following treatment with MNU and MMS are distinct, and that the effect of MMS is probably to speed up the process of viral leukemogenesis.
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Affiliation(s)
- W Warren
- Institute of Cancer Research, Chester Beatty Laboratories, London Hospital Medical College, England
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Hollinger RC, Clark JP. Deterrence in the workplace: perceived certainty, perceived severity, and employee theft. Soc Forces 1983; 62:398-418. [PMID: 10264479 DOI: 10.1093/sf/62.2.398] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The phenomenon of employee theft is examined empirically, utilizing a deterrence paradigm. Employees selected randomly from three different industry sectors and metropolitan areas were asked to self-report their involvement in a number of property theft activities within the employment setting. Using a weighted least-squares logit regression analysis, the study found that the perception of both the certainty and severity of organizational sanctions were related to employee theft. Males reported more theft than did females, but contrary to previous research, no gender/certainty or gender/severity interactions were observed. The best-fit model did, however, contain two significant first-order interactions: age/certainty and age/severity. These interactions strongly suggest that younger employees are not as deterrable as their older peers, especially under conditions of both high certainty and high severity of punishment. While a number of possible explanations might account for differential deterrability according to age, a commitment to or stakes in conformity explanation is proposed.
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Abstract
NZB x NZW (NZB x W) F1 hybrid mice spontaneously develop a disease most prominently characterized by immune complex glomerulonephritis (GN), which seems to be associated with both antibodies to DNA and to the serum retroviral envelope glycoprotein, gp70. To evaluate the contribution of each of these autoimmune responses to the pathogenesis of the GN, we studied NZB x W F2 mice in which the two responses appeared to segregate relatively independently. Use of this model permitted analysis of possible correlations between each response and the G.N. The presence of circulating anti-gp 70-complexed gp70 correlated significantly with the development of fatal GN and one could predict the course of renal disease by computing the rising serum levels of gp70 complexed with antibodies. In contrast, the presence of free antibodies to either double-stranded or single-stranded DNA was not significantly associated with the development of fatal GN. This association of anti-gp70 antibody production with these animals' early death from GN strongly suggests that the gene(s) governing production of antibodies to serum retroviral gp70 may be one of the major genes responsible for spontaneous renal disease segregated in NZB x W F2 generations.
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Bolton TB, Clark JP. Actions of various muscarinic agonists on membrane potential, potassium efflux, and contraction of longitudinal muscle of guinea-pig intestine. Br J Pharmacol 1981; 72:319-34. [PMID: 7214100 PMCID: PMC2071508 DOI: 10.1111/j.1476-5381.1981.tb09131.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
1 Depolarizations were recorded intracellularly in smooth muscle from the taenia of the guinea-pig caecum in response to the iontophoretic application of acetylcholine, carbachol, oxotremorine-M, methylfurmethide, hexyl trimethylammonium and tetramethylammonium (TMA). 2 No differences between the iontophoretic responses to agonists stable to cholinesterase were detected. 3 The latency and time to peak of acetylcholine-induced depolarizations were less than those to stable agonists, and the response was briefer and less complex in shape. These differences were reduced, or disappeared, upon inhibition of cholinesterase. 4 The rate of loss of 42K and changes in length were measured in superfused strips weighing about 10 mg of separated longitudinal muscle of guinea-pig ileum. 5 Acetylcholine, carbachol, methylfurmethide, butyltrimethylammonium and TMA contracted the muscle and increased the rate of loss of 42K. 6 Contrary to previous reports, no evidence of a selective action of any of these agonists on 42K loss was detected. TMA appeared to be a partial agonist in evoking 42K loss, although it produced a maximum contraction. 7 The maximum 42K efflux produced by acetylcholine was about 40% of the maximum evoked by application of carbachol or methylfurmethide. If cholinesterase was inhibited, the 42K efflux evoked by maximally effective concentrations of acetylcholine was comparable to that evoked by a stable agonist. 8 These results are consistent with the idea that the muscarinic agonists used interact in an essentially similar way with muscarinic receptors to produce their effects on membrane potential, permeability, and tension.
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Abstract
1. Shortening and rate of loss of (42)K were studied in strips of longitudinal muscle taken from guinea-pig ileum.2. Carbachol, histamine and raising the external potassium concentration, [K(+)](o), to 120 mm in the presence of atropine caused equal maximal shortenings of the muscle, but unequal maximal increases in (42)K efflux: maximal (42)K effluxes obtainable in response to raised [K(+)](o) and histamine were about (2/3) and (1/3) respectively of the maximal efflux in response to carbachol. In the absence of atropine the increase in (42)K efflux produced by 120 mm-[K(+)](o) was about 50% larger, probably because of the release of acetylcholine from nerve endings in the tissue.3. If inhibitors of histamine metabolism were applied, or a H(2)-receptor blocker (cimetidine), the maximum (42)K efflux produced by histamine was not increased. An analogue of histamine reputed to resist metabolic degradation did not produce a larger increase in (42)K efflux than histamine. The smaller maximal effect of histamine on (42)K efflux than carbachol may be because it can open fewer ion channels in the smooth muscle membrane.4. The ratio of the concentrations producing 50% maximal shortening and 50% maximal (42)K efflux was about 1:1.3 for raised [K(+)](o) but about 1:20 for histamine and carbachol. Depolarization by raising [K(+)](o) appears to be less effective in causing tension development than similar depolarizations produced by carbachol or histamine.5. The relative effects of carbachol, histamine and raised [K(+)](o) were discussed in the light of their similar depolarizing actions. Increases in (42)K efflux did not appear to be caused primarily either by contraction or by depolarization of the muscle. Access of the stimulant to cells and receptors other than those which are superficially situated was suggested as being an important factor in deciding the smaller increase in (42)K efflux seen with some stimulants. Histamine receptors may be fewer in number than muscarinic receptors and less able in their activated form to open channels through which potassium ions can escape.
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Bolton TB, Clark JP, Kitamura K, Lang RJ. Evidence that histamine and carbachol may open the same ion channels in longitudinal smooth muscle of guinea-pig ileum. J Physiol 1981; 320:363-79. [PMID: 6275077 PMCID: PMC1244053 DOI: 10.1113/jphysiol.1981.sp013955] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
1. Membrane potential was recorded intracellularly by micro-electrode in separated longitudinal muscle of guinea-pig ileum. Electrotonic potentials were evoked in longitudinal strips by passing current between large external electrodes in the partition chamber.2. Histamine increased the frequency of action potential discharge at low concentrations and depolarized the membrane. At higher concentrations it caused substantial depolarization and action potential discharge was abolished. Carbachol had similar actions but the maximal depolarization by carbachol (using 10(-4)m) was some 4-5 mV greater than maximal depolarization by histamine (using 10(-4)m).3. The change in size of evoked electrotonic potentials was used to estimate the effects of carbachol and histamine on the conductance of the smooth muscle membrane. The equilibrium potentials for histamine and carbachol depolarizations were estimated from their relative effects on potential and conductance and were found to be not significantly different; measurements of the effects on conductance showed that 10(-4)m-histamine increased conductance about 8-fold whilst 10(-4)m-carbachol had a much greater effect on conductance. This difference could explain the differing maximal depolarizing effects of these agents if both were assumed to open channels having the same ionic selectivity (i.e. equilibrium potential).4. The efflux of (42)K was studied in separated strips of longitudinal ileal muscle from guinea-pig. In the presence of a concentration of carbachol (2 x 10(-5)m or 10(-4)m) having a maximal effect on (42)K efflux rate, histamine (10(-4)m) did not increase efflux further although 120 mm-potassium did so. Experiments with the irreversible muscarinic receptor blocker, propylbenzilylcholine mustard, indicated that the number of muscarinic receptors did not limit the (42)K efflux response to carbachol and it was suggested that the response was limited by the availability of ion channels which could be opened by activated muscarinic receptors.5. Contractions to histamine and carbachol in 120 mm-potassium depolarizing solution were followed upon washing by a relaxation below basal tension. Carbachol, but not histamine, showed a pronounced and long lasting secondary contraction following this relaxation.6. These results are consistent with the idea that activated histamine and activated muscarinic receptors open the same ion channels in the smooth muscle membrane to produce depolarization, increased action potential discharge and contraction, although muscarinic receptors can open more of these. However, there was evidence that the opening of these channels is not the only pathway between receptor activation and contraction.
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Kessler II, Clark JP. Saccharin, cyclamate, and human bladder cancer. No evidence of an association. JAMA 1978; 240:349-55. [PMID: 660869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
An epidemiologic study designed to elucidate the possible roles of the artificial sweeteners saccharin and cyclamate in human urinary bladder cancer was recently completed. The previous intake of each of these substances among 519 patients with histopathologically confirmed bladder cancer and an equal number of matching controls in metropolitan Baltimore did not differ significantly in frequency, quantity, or duration. These normal findings persisted after simultaneous adjustment for the effects of smoking, occupation, age, diabetes mellitus, and a number of other potentially confounding factors. They are substantiated by the failure of the relative risk of bladder cancer to increase with increasing exposure to artificial sweeteners. It is concluded that neither saccharin nor cyclamate is likely to be carcinogenic in man, at least at the moderate dietary ingestion levels reported by the patient sample.
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Clark JP, Green JC. An investigation of the electronic structure of bis(η-cyclo-octatetraene)-actinoids by helium-(I) and -(II) photoelectron spetroscopy. ACTA ACUST UNITED AC 1977. [DOI: 10.1039/dt9770000505] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Kilmore MA, Clark JP, Holmes JA. Effect of ketamine on myocardial irritability. Res Commun Chem Pathol Pharmacol 1974; 8:723-6. [PMID: 4472576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Kilmore MA, Clark JP. Comparison of myocardial irritability of selected anesthetics. Res Commun Chem Pathol Pharmacol 1971; 2:837-58. [PMID: 4405003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Summers GF, Burke M, Saltiel S, Clark JP. DIMENSIONS OF PERSONALITY: I. CONJOINT FACTOR STRUCTURE OF GUILFORD AND CATTELL TRAIT MARKERS. Multivariate Behav Res 1971; 6:35-62. [PMID: 26744793 DOI: 10.1207/s15327906mbr0601_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The Work Component Study was administered to high school students and the stability of the structure of the variables of work motivation examined. The strudure found among college students and college trained employees is well developed at the high school level. The relationship of work motivations to personality variables and to aspirations is also dear: However, there is little relationship found between work motivations and status variables of the students or their parents. This was unanticipated and oreates a question regarding the sources of work motivations.
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