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Salzmann J, Linderholm OP, Guyomard JL, Paques M, Simonutti M, Lecchi M, Sommerhalder J, Dubus E, Pelizzone M, Bertrand D, Sahel J, Renaud P, Safran AB, Picaud S. Subretinal electrode implantation in the P23H rat for chronic stimulations. Br J Ophthalmol 2006; 90:1183-7. [PMID: 16754649 PMCID: PMC1857388 DOI: 10.1136/bjo.2005.089110] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND In age related macular degeneration and inherited dystrophies, preservation of retinal ganglion cells has been demonstrated. This finding has led to the development of various models of subretinal or epiretinal implant in order to restore vision. This study addresses the development of a polyimide subretinal electrode platform in the dystrophic P23H rat in vivo. METHODS A technique was developed for implanting a subretinal electrode into the subretinal space and stabilising the distal extremity of the cabling on the rat cranium in order to allow future electrical stimulations of the retina. RESULTS In vivo imaging of the retina with the scanning laser ophthalmoscope demonstrated reabsorption of the surgically induced retinal detachment and the absence of major tissue reactions. These in vivo observations were confirmed by retinal histology. The extraocular fixation system on the rat cranium was effective in stabilising the distal connector for in vivo stimulation. CONCLUSION This study demonstrates that a retinal implant can be introduced into the subretinal space of a dystrophic rat with a stable external connection for repeatable electrical measurements and stimulation. This in vivo model should therefore allow us to evaluate the safety and efficacy of electrical stimulations on dystrophic retina.
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Gahide G, El Ferzli J, Bertrand D, Tron C, Dacher JN. [Myocarditis versus myocardial infarction in diabetic patients: a new role for non invasive imaging]. JOURNAL DE RADIOLOGIE 2006; 87:388-90. [PMID: 16691167 DOI: 10.1016/s0221-0363(06)74018-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
A young diabetic patient was referred to our institution for clinical symptoms of myopericarditis. Cardiac MRI and MDCT of the coronary arteries were performed successively. They demonstrated an acute myocardial infarction related to a left circumflex coronary artery occlusion which was treated by stent angioplasty. This case suggests that cardiac MR and possibly cardiac MDCT could be proposed in patients with a suspected myopericarditis, especially if diabetes mellitus is associated.
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Preys S, Mazerolles G, Courcoux P, Samson A, Fischer U, Hanafi M, Bertrand D, Cheynier V. Relationship between polyphenolic composition and some sensory properties in red wines using multiway analyses. Anal Chim Acta 2006. [DOI: 10.1016/j.aca.2005.10.082] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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129
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Bréchat PH, Bérard A, Magnin-Feysot C, Segouin C, Bertrand D. Usagers et politiques de santé : bilans et perspectives. SANTE PUBLIQUE 2006; 18:245-62. [PMID: 16886548 DOI: 10.3917/spub.062.0245] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The French public power-base imagined that the involvement and participation of consumers in decision-making could render the debates on health policies more transparent when faced with the opposing professional and techno-administrative logics. One could also ask oneself what is the true reality of this participation. The research strategy is based on the intersection and overlap of data resulting from the analysis of minutes reported from semi-guided interviews with regional and national referential persons, consumers and from documents concerning the construction and implementation of national, regional and local health policies. This study demonstrates that, from 1996 to 2002, consumers were associated with and implicated in the development and implementation of national, regional and local health policies. Exemplary success stories exist which testify to the possibility of anchoring a democratic consultation model in health institutions irrespective of the level of decision-making, application or operationalisation. Recommendations are proposed in order to strengthen these dynamic forces and relationships.
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Ackermann M, Ahrens J, Bai X, Bartelt M, Barwick SW, Bay RC, Becka T, Becker JK, Becker KH, Berghaus P, Bernardini E, Bertrand D, Boersma DJ, Böser S, Botner O, Bouchta A, Bouhali O, Burgess C, Burgess T, Castermans T, Chirkin D, Collin B, Conrad J, Cooley J, Cowen DF, Davour A, De Clercq C, de los Heros CP, Desiati P, DeYoung T, Ekström P, Feser T, Gaisser TK, Ganugapati R, Geenen H, Gerhardt L, Goldschmidt A, Groß A, Hallgren A, Halzen F, Hanson K, Hardtke DH, Harenberg T, Hauschildt T, Helbing K, Hellwig M, Herquet P, Hill GC, Hodges J, Hubert D, Hughey B, Hulth PO, Hultqvist K, Hundertmark S, Jacobsen J, Kampert KH, Karle A, Kestel M, Kohnen G, Köpke L, Kowalski M, Kuehn K, Lang R, Leich H, Leuthold M, Liubarsky I, Lundberg J, Madsen J, Marciniewski P, Matis HS, McParland CP, Messarius T, Minaeva Y, Miočinović P, Morse R, Münich K, Nahnhauer R, Nam JW, Neunhöffer T, Niessen P, Nygren DR, Olbrechts P, Pohl AC, Porrata R, Price PB, Przybylski GT, Rawlins K, Resconi E, Rhode W, Ribordy M, Richter S, Rodríguez Martino J, Sander HG, Schlenstedt S, Schneider D, Schwarz R, Silvestri A, Solarz M, Spiczak GM, Spiering C, Stamatikos M, Steele D, Steffen P, Stokstad RG, Sulanke KH, Taboada I, Tarasova O, Thollander L, Tilav S, Wagner W, Walck C, Walter M, Wang YR, Wiebusch CH, Wischnewski R, Wissing H, Woschnagg K. Optical properties of deep glacial ice at the South Pole. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jd006687] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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131
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López-Anglada E, Paz-Aparicio J, Bertrand D, Gosálbez J, Núñez-Batalla D, Paz-Jiménez J. Influencia de la aprotinina en el sangrado postoperatorio de la artroplastia total de rodilla. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s0482-5985(05)74449-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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132
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Colinet B, Jacot W, Bertrand D, Lacombe S, Bozonnat MC, Daurès JP, Pujol JL. A new simplified comorbidity score as a prognostic factor in non-small-cell lung cancer patients: description and comparison with the Charlson's index. Br J Cancer 2005; 93:1098-105. [PMID: 16234816 PMCID: PMC2361505 DOI: 10.1038/sj.bjc.6602836] [Citation(s) in RCA: 165] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2005] [Revised: 09/15/2005] [Accepted: 09/16/2005] [Indexed: 11/08/2022] Open
Abstract
Treatment of non-small-cell lung cancer (NSCLC) might take into account comorbidities as an important variable. The aim of this study was to generate a new simplified comorbidity score (SCS) and to determine whether or not it improves the possibility of predicting prognosis of NSCLC patients. A two-step methodology was used. Step 1: An SCS was developed and its prognostic value was compared with classical prognostic determinants in the outcome of 735 previously untreated NSCLC patients. Step 2: the SCS reliability as a prognostic determinant was tested in a different population of 136 prospectively accrued NSCLC patients with a formal comparison between SCS and the classical Charlson comorbidity index (CCI). Prognosis was analysed using both univariate and multivariate (Cox model) statistics. The SCS summarised the following variables: tobacco consumption, diabetes mellitus and renal insufficiency (respective weightings 7, 5 and 4), respiratory, neoplastic and cardiovascular comorbidities and alcoholism (weighting=1 for each item). In step 1, aside from classical variables such as age, stage of the disease and performance status, SCS was a statistically significant prognostic variable in univariate analyses. In the Cox model weight loss, stage grouping, performance status and SCS were independent determinants of a poor outcome. There was a trend towards statistical significance for age (P=0.08) and leucocytes count (P=0.06). In Step 2, both SCS and well-known prognostic variables were found as significant determinants in univariate analyses. There was a trend towards a negative prognostic effect for CCI. In multivariate analysis, stage grouping, performance status, histology, leucocytes, lymphocytes, lactate dehydrogenase, CYFRA 21-1 and SCS were independent determinants of a poor prognosis. CCI was removed from the Cox model. In conclusion, the SCS, constructed as an independent prognostic factor in a large NSCLC patient population, is validated in another prospective population and appears more informative than the CCI in predicting NSCLC patient outcome.
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Jacot W, Colinet B, Bertrand D, Lacombe S, Bozonnat M, Pujol J. PD-073 A new simplified comorbidity score as prognostic factor innon-small cell lung cancer (NSCLC) Patients: Description and comparison with the Charlson's index. Lung Cancer 2005. [DOI: 10.1016/s0169-5002(05)80406-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Smith Fawzi MC, Lambert W, Singler JM, Tanagho Y, Léandre F, Nevil P, Bertrand D, Claude MS, Bertrand J, Louissaint M, Jeannis L, Mukherjee JS, Goldie S, Salazar JJ, Farmer PE. Factors associated with forced sex among women accessing health services in rural Haiti: implications for the prevention of HIV infection and other sexually transmitted diseases. Soc Sci Med 2005; 60:679-89. [PMID: 15571887 PMCID: PMC3407680 DOI: 10.1016/j.socscimed.2004.06.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The goals of the current study were to: (1) estimate the prevalence of forced sex among women accessing services at a women's health clinic in rural Haiti; and (2) examine factors associated with forced sex in this population. Based on data from a case-control study of risk factors for sexually transmitted diseases (STDs), a cross-sectional analysis to examine factors associated with forced sex was performed. A number of factors related to gender inequality/socioeconomic vulnerability placed women in rural Haiti at higher risk of forced sex. The strongest factors associated with forced sex in multivariate analyses were: age, length of time in a relationship, occupation of the woman's partner, STD-related symptoms, and factors demonstrating economic vulnerability. The findings suggest that prevention efforts must go beyond provision of information and education to the pursuit of broader initiatives at both local and national levels. At the community level, policy-makers should consider advancing economic opportunities for women who are vulnerable to forced sex. Improving access to community-based income-generating activities may begin to address this problem. However, the viability of these local projects depends largely upon Haiti's 'macro-economic' situation. In order to ensure the success of local initiatives, external humanitarian and development assistance to Haiti should be supported. By broadening the definition of "prevention" interventions, we may begin to address the systemic problems that contribute to the occurrence of forced sex and the increasing incidence of HIV infection throughout the world, such as gender inequality and economic vulnerability. Taking into account factors influencing risk at the local level as well as the macro-level will potentially improve our capacity to reduce the risk of forced sex and the spread of STDs, including HIV infection, for millions of women living in poverty worldwide.
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Guillermin P, Camps C, Bertrand D. DETECTION OF BRUISES ON APPLES BY NEAR INFRARED REFLECTANCE SPECTROSCOPY. ACTA ACUST UNITED AC 2005. [DOI: 10.17660/actahortic.2005.682.182] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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136
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Pomey MP, François P, Contandriopoulos AP, Tosh A, Bertrand D. Paradoxes of French accreditation. Qual Saf Health Care 2005; 14:51-5. [PMID: 15692004 PMCID: PMC1743956 DOI: 10.1136/qshc.2004.011510] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The accreditation system introduced into the French healthcare system in 1996 has five particular characteristics: (1) it is mandatory for all healthcare establishments; (2) it is performed by an independent government agency; (3) surveyors have to report all instances of non-compliance with safety regulations; (4) the accreditation report is delivered to regional administrative authorities and a summary is made available to the public; and (5) regional administrative authorities can use the information contained in the accreditation report to revise hospital budgets. These give rise to a number of paradoxes: (1) the fact that accreditation is mandatory lends itself to ambiguity and likens the process to an inspection; (2) the fact that decision makers can use the information contained in the accreditation report for resource allocation can incite establishments to adopt strategic behaviours aimed merely at complying with the accreditation manual; and (3) there is a tendency for establishments to reduce quality processes to nothing more than the completion of accreditation and to focus efforts on standardizing practices and resolving safety issues to the detriment of organizational development. All accreditation systems must be aware of these paradoxes and decide on the level of government involvement and the relationship between accreditation and resource allocation. With time, accreditation in France could benefit from both a professionally driven system and from the increased amount of freedom to focus on quality improvement which is necessary for organizational development.
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137
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López-Anglada E, Paz-Aparicio J, Bertrand D, Gosálbez J, Núñez-Batalla D, Paz-Jiménez J. Influencia de la aprotinina en el sangrado postoperatorio de la artroplastia total de rodilla. Rev Esp Cir Ortop Traumatol (Engl Ed) 2005. [DOI: 10.1016/s1888-4415(05)76341-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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138
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139
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Metz S, Bertsch A, Bertrand D, Renaud P. Flexible polyimide probes with microelectrodes and embedded microfluidic channels for simultaneous drug delivery and multi-channel monitoring of bioelectric activity. Biosens Bioelectron 2004; 19:1309-18. [PMID: 15046764 DOI: 10.1016/j.bios.2003.11.021] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2003] [Revised: 11/20/2003] [Accepted: 11/26/2003] [Indexed: 10/26/2022]
Abstract
The study of intracellular communication requires devices that can not only monitor the bioelectric activity, but also control and observe the biochemical environment at the cellular level. This paper reports on the development and characterisation of implantable polyimide microprobes that allow simultaneous, selective chemical delivery/probing and multi-channel recording/stimulation of bioelectric activity. The key component of the system is a flexible polyimide substrate with embedded microchannels that is batch-fabricated combining polyimide micromachining and a lamination technique. The devices provide platinum microelectrodes on both sides of the polyimide substrate with an active surface between 20 microm x 20 microm and 50 microm x 50 microm. The embedded microchannels permit highly localised drug delivery or probing at the tip of the device via channel outlets adjacent to the microelectrodes. The microelectrodes were characterised by electrical impedance spectroscopy and the microchannels were studied in microflow experiments. Two different fluid delivery schemes were explored in two different designs. The first device type consists of a simple combination of microchannels and microelectrodes on one substrate. Liquids are ejected at the tip of the device by pressure injection techniques. The second device was inspired by the so-called U-tube concept allowing for highly localised delivery of controlled amounts of liquids in the picoliters range. Thus, the influence of chemical compounds on the electrical activity of cells can be studied with high temporal and spatial resolution. The flexible, implantable devices can be used for studying the chemical and electrical information exchange and communication of cells in in vivo and in vitro experiments.
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Ogier R, Liu X, Tribollet E, Bertrand D, Raggenbass M. Identified spinal motoneurons of young rats possess nicotinic acetylcholine receptors of the heteromeric family. Eur J Neurosci 2004; 20:2591-7. [PMID: 15548202 DOI: 10.1111/j.1460-9568.2004.03746.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The aim of the present study was to determine whether, in young rats, spinal motoneurons possess functional nicotinic acetylcholine receptors. Motoneurons were identified either by retrograde labelling or by choline acetyltransferase immunohistochemistry. Whole-cell recordings were performed in spinal cord slices cut at the lumbar level. In voltage clamp, acetylcholine evoked a rapidly activating inward current. In current clamp, it depolarized the motoneuron membrane and induced action potential firing. The acetylcholine-evoked current was strongly reduced by d-tubocurarine or dihydro-beta-erythroidine, broad spectrum nicotinic antagonists, but was almost insensitive to methyllycaconitine, a nicotinic antagonist selective for receptors containing the alpha7 subunit. Moreover, exo-2-(2-pyridyl)-7-azabicyclo[2.2.1]heptane, an alpha7-specific agonist, was without effect. In young animals, light-microscopic autoradiography showed that in the central grey matter all laminae were intensely and equally labelled by [3H]epibatidine. A dense [125I]-alpha-bungarotoxin binding was also found in all laminae, with slightly lower levels in the superficial layers of the dorsal horns and in the ventral part of the grey matter. In adults, the density of [3H]epibatidine binding sites was much lower in the entire grey matter, except in layer 2 of the dorsal horn, and [125I]-alpha-bungarotoxin binding sites were present only in some selected areas. Our data indicate that spinal motoneurons possess functional nicotinic receptors of the heteromeric type and suggest that nicotinic cholinergic transmission may play a significant role in the developing spinal cord.
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Bertrand D, Douvrin F, Gerardin E, Clavier E, Proust F, Thiebot J. Diagnosis of spinal dural arteriovenous fistula with multidetector row computed tomography: a case report. Neuroradiology 2004; 46:851-4. [PMID: 15448953 DOI: 10.1007/s00234-004-1263-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Spinal dural arteriovenous fistulas are a rare cause of myelopathy. Nonspecific symptoms may delay the diagnosis. Magnetic resonance imaging and spinal angiography are routinely used to establish the diagnosis. In our case abnormalities on magnetic resonance imaging only suggested spinal dural arteriovenous fistulas. Multidetector row computed tomography (MRCT) led to the diagnosis which was confirmed by angiography.
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Tron C, Dacher JN, Eltchaninoff H, Gerbaud E, Bertrand D, Cribier A. [Non-invasive coronary angiography by multidetector spiral computed tomography and magnetic resonance imaging]. Ann Cardiol Angeiol (Paris) 2004; 53:239-44. [PMID: 15532448 DOI: 10.1016/j.ancard.2004.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Coronary angiography is the reference standard to confirm the presence and severity of coronary stenoses. Given the invasiveness of this procedure, a noninvasive mean allowing to visualize coronary anatomy would be of obvious clinical interest. Multidetector spiral computed tomography and magnetic resonance imaging are new and promising techniques for noninvasive detection of significant coronary stenoses. The purpose of this article is to review the present knowledge on these noninvasive techniques.
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Abstract
While it has long been documented that nicotine contained in tobacco leaves gives rise to major public health problems it has also been observed that this alkaloid can have beneficial effects. However, it is only with the identification of a family of genes coding for the neuronal nicotinic acetylcholine receptors and increased knowledge of their expression and function in the central nervous system that these receptors have received attention concerning their potential as drug targets. In light of the latest findings about nicotinic acetylcholine receptors and their involvement in disease states we review the possibility to design new drugs targeted to these ligand-gated channels. Beneficial and possible undesirable actions of agonists, antagonists and allosteric modulators are discussed and placed in perspective of our most recent knowledge.
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Smith Fawzi MC, Lambert W, Singler JM, Koenig SP, Léandre F, Nevil P, Bertrand D, Claude MS, Bertrand J, Salazar JJ, Louissaint M, Joanis L, Farmer PE. Prevalence and risk factors of STDs in rural Haiti: implications for policy and programming in resource-poor settings. Int J STD AIDS 2004; 14:848-53. [PMID: 14678595 PMCID: PMC6276366 DOI: 10.1258/095646203322556200] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The goals of the current study are to: (1) estimate the prevalence of sexually transmitted diseases (STDs) among women accessing services at a women's health clinic in rural Haiti; and (2) identify risk factors for STDs in this setting. The design is a case control study, comparing risk factors for women who demonstrated positive laboratory results for chlamydia and/or gonorrhoea to women who tested negative for both of these pathogens. The strongest risk factors for chlamydia and/or gonorrhoea were largely economic variables, with work as a domestic servant increasing the risk by four-fold. Working as a market vendor reduced a woman's risk of having an STD by approximately 45%. Given that economic factors are strongly associated with STD risk in this context, one potential mechanism for reducing the risk of STDs, including HIV, would involve increasing economic opportunities for women in rural Haiti.
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Ahrens J, Bai X, Barwick SW, Becka T, Becker JK, Bernardini E, Bertrand D, Binon F, Biron A, Boersma DJ, Böser S, Botner O, Bouchta A, Bouhali O, Burgess T, Carius S, Castermans T, Chen A, Chirkin D, Collin B, Conrad J, Cooley J, Cowen DF, Davour A, De Clercq C, DeYoung T, Desiati P, Dewulf JP, Ekström P, Feser T, Gaisser TK, Ganugapati R, Gaug M, Geenen H, Gerhardt L, Goldschmidt A, Gross A, Hallgren A, Halzen F, Hanson K, Hardtke R, Harenberg T, Hauschildt T, Helbing K, Hellwig M, Herquet P, Hill GC, Hubert D, Hughey B, Hulth PO, Hultqvist K, Hundertmark S, Jacobsen J, Karle A, Kestel M, Köpke L, Kowalski M, Kuehn K, Lamoureux JI, Leich H, Leuthold M, Lindahl P, Liubarsky I, Madsen J, Mandli K, Marciniewski P, Matis HS, McParland CP, Messarius T, Minaeva Y, Miocinović P, Morse R, Münich K, Nahnhauer R, Neunhöffer T, Niessen P, Nygren DR, Ogelman H, Olbrechts P, Pérez de los Heros C, Pohl AC, Porrata R, Price PB, Przybylski GT, Rawlins K, Resconi E, Rhode W, Ribordy M, Richter S, Rodríguez Martino J, Sander HG, Schinarakis K, Schlenstedt S, Schmidt T, Schneider D, Schwarz R, Silvestri A, Solarz M, Spiczak GM, Spiering C, Stamatikos M, Steele D, Steffen P, Stokstad RG, Sulanke KH, Taboada I, Thollander L, Tilav S, Wagner W, Walck C, Wang YR, Wiebusch CH, Wiedemann C, Wischnewski R, Wissing H, Woschnagg K, Yodh G. Search for extraterrestrial point sources of neutrinos with AMANDA-II. PHYSICAL REVIEW LETTERS 2004; 92:071102. [PMID: 14995836 DOI: 10.1103/physrevlett.92.071102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2003] [Indexed: 05/24/2023]
Abstract
We present the results of a search for point sources of high-energy neutrinos in the northern hemisphere using AMANDA-II data collected in the year 2000. Included are flux limits on several active-galactic-nuclei blazars, microquasars, magnetars, and other candidate neutrino sources. A search for excesses above a random background of cosmic-ray-induced atmospheric neutrinos and misreconstructed downgoing cosmic-ray muons reveals no statistically significant neutrino point sources. We show that AMANDA-II has achieved the sensitivity required to probe known TeV gamma-ray sources such as the blazar Markarian 501 in its 1997 flaring state at a level where neutrino and gamma-ray fluxes are equal.
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Lecchi M, Marguerat A, Ionescu A, Pelizzone M, Renaud P, Sommerhalder J, Safran AB, Tribollet E, Bertrand D. Ganglion cells from chick retina display multiple functional nAChR subtypes. Neuroreport 2004; 15:307-11. [PMID: 15076758 DOI: 10.1097/00001756-200402090-00019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We have examined the properties of nicotinic acetylcholine receptors in embryonic chick retinal ganglion cells. Ganglion cells, identified according to morphological and physiological criteria, displayed spontaneous or induced action potentials. In 94/99 cells acetylcholine pulses evoked responses. In current clamp mode, acetylcholine provoked membrane depolarization and triggered action potentials. Under voltage clamp conditions, acetylcholine evoked inward currents that were readily blocked by d-tubocurarine. Antagonists specific for homomeric (alpha-bungarotoxin) and heteromeric (dihydro-beta-erythroidine) receptors revealed that ganglion cells express multiple functional receptor subtypes. These findings demonstrate that ACh modulates the electrical activity of these cells and is likely to mediate synaptic transmission. The presence of multiple receptor subtypes may contribute to processing and transmission of information in the retina.
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Tribollet E, Bertrand D, Marguerat A, Raggenbass M. Comparative distribution of nicotinic receptor subtypes during development, adulthood and aging: an autoradiographic study in the rat brain. Neuroscience 2004; 124:405-20. [PMID: 14980390 DOI: 10.1016/j.neuroscience.2003.09.028] [Citation(s) in RCA: 167] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/22/2003] [Indexed: 10/26/2022]
Abstract
The distribution in the rat brain of high affinity nicotinic heteromeric acetylcholine receptors and of low affinity nicotinic, alpha7-containing, homomeric receptors was studied using in vitro light microscopic autoradiography. As ligands, we used [3H]epibatidine, or [125I]epibatidine, and [125I]alpha-bungarotoxin, respectively. In adult animals, the two types of binding sites were widely distributed in many different brain structures, including the brainstem, cerebellum, mesencephalic structures, limbic system and cortex, but their anatomical distribution differed markedly. Only in rare instances could a co-localization be observed, for example in the superficial layer of the superior colliculus. In developing animals, both types of labeling were strongly expressed during embryonic and postnatal phases. Their distributions were qualitatively similar to those observed in adult animals, with a few noticeable exceptions in the cerebral cortex, hippocampus and brain stem. In aging animals, neither the distribution nor the density of nicotinic binding sites was significantly altered. Our conclusions are the following. (a) There is little overlap in the distribution of heteromeric and alpha7-containing homomeric nicotinic receptors in the rat brain. (b) The abundance of neuronal nicotinic receptors during embryonic and postnatal development suggests that they may play a role in the establishment of neuronal connectivity. (c) The expression of neuronal nicotinic receptors is unaltered in middle aged animals, suggesting that in the rat these receptors do not play any major role in aging process.
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Bertrand D, González-Busto I, Solís A, Paz-Aparicio J, Núñez-Batalla D, Paz-Jiménez J. Fracturas pertrocantéreas de fémur en el anciano: clavo Gamma y clavo PFN. Estudio comparativo. Rev Esp Cir Ortop Traumatol (Engl Ed) 2004. [DOI: 10.1016/s1888-4415(04)76162-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Hogg RC, Raggenbass M, Bertrand D. Nicotinic acetylcholine receptors: from structure to brain function. Rev Physiol Biochem Pharmacol 2003; 147:1-46. [PMID: 12783266 DOI: 10.1007/s10254-003-0005-1] [Citation(s) in RCA: 365] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels and can be divided into two groups: muscle receptors, which are found at the skeletal neuromuscular junction where they mediate neuromuscular transmission, and neuronal receptors, which are found throughout the peripheral and central nervous system where they are involved in fast synaptic transmission. nAChRs are pentameric structures that are made up of combinations of individual subunits. Twelve neuronal nAChR subunits have been described, alpha2-alpha10 and beta2-beta4; these are differentially expressed throughout the nervous system and combine to form nAChRs with a wide range of physiological and pharmacological profiles. The nAChR has been proposed as a model of an allosteric protein in which effects arising from the binding of a ligand to a site on the protein can lead to changes in another part of the molecule. A great deal is known about the structure of the pentameric receptor. The extracellular domain contains binding sites for numerous ligands, which alter receptor behavior through allosteric mechanisms. Functional studies have revealed that nAChRs contribute to the control of resting membrane potential, modulation of synaptic transmission and mediation of fast excitatory transmission. To date, ten genes have been identified in the human genome coding for the nAChRs. nAChRs have been demonstrated to be involved in cognitive processes such as learning and memory and control of movement in normal subjects. Recent data from knockout animals has extended the understanding of nAChR function. Dysfunction of nAChR has been linked to a number of human diseases such as schizophrenia, Alzheimer's and Parkinson's diseases. nAChRs also play a significant role in nicotine addiction, which is a major public health concern. A genetically transmissible epilepsy, ADNFLE, has been associated with specific mutations in the gene coding for the alpha4 or beta2 subunits, which leads to altered receptor properties.
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Ahrens J, Bai X, Barwick SW, Bay RC, Becka T, Becker KH, Bernardini E, Bertrand D, Biron A, Boeser S, Botner O, Bouchta A, Bouhali O, Burgess T, Carius S, Castermans T, Chirkin D, Conrad J, Cooley J, Cowen DF, Davour A, De Clercq C, DeYoung T, Desiati P, Doksus P, Ekström P, Feser T, Gaisser TK, Ganugapati R, Gaug M, Geenen H, Gerhardt L, Goldschmidt A, Hallgren A, Halzen F, Hanson K, Hardtke R, Hauschildt T, Hellwig M, Herquet P, Hill GC, Hulth PO, Hughey B, Hultqvist K, Hundertmark S, Jacobsen J, Karle A, Kuehn K, Kim J, Köpke L, Kowalski M, Lamoureux JI, Leich H, Leuthold M, Lindahl P, Liubarsky I, Madsen J, Mandli K, Marciniewski P, Matis H, McParland CP, Messarius T, Miller TC, Minaeva Y, Miocinović P, Mock PC, Morse R, Neunhöffer T, Niessen P, Nygren DR, Ogelman H, Olbrechts P, Pérez de los Heros C, Pohl AC, Porrata R, Price PB, Przybylski GT, Rawlins K, Resconi E, Rhode W, Ribordy M, Richter S, Martino JR, Romenesko P, Ross D, Sander HG, Schlenstedt S, Schinarakis K, Schmidt T, Schneider D, Schwarz R, Silvestri A, Solarz M, Stamatikos M, Spiczak GM, Spiering C, Steele D, Steffen P, Stokstad RG, Sulanke KH, Taboada I, Tilav S, Wagner W, Walck C, Wang YR, Wiebusch CH, Wiedemann C, Wischnewski R, Wissing H, Woschnagg K, Wu W, Yodh G, Young S. Limits on diffuse fluxes of high energy extraterrestrial neutrinos with the AMANDA-B10 detector. PHYSICAL REVIEW LETTERS 2003; 90:251101. [PMID: 12857122 DOI: 10.1103/physrevlett.90.251101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2003] [Indexed: 05/24/2023]
Abstract
Data from the AMANDA-B10 detector taken during the austral winter of 1997 have been searched for a diffuse flux of high energy extraterrestrial muon neutrinos. This search yielded no excess events above those expected from background atmospheric neutrinos, leading to upper limits on the extraterrestrial neutrino flux measured at the earth. For an assumed E-2 spectrum, a 90% classical confidence level upper limit has been placed at a level E2Phi(E)=8.4 x 10(-7) cm(-2) s(-1) sr(-1) GeV (for a predominant neutrino energy range 6-1000 TeV), which is the most restrictive bound placed by any neutrino detector. Some specific predicted model spectra are excluded. Interpreting these limits in terms of the flux from a cosmological distributions of sources requires the incorporation of neutrino oscillations, typically weakening the limits by a factor of 2.
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