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Ranney ML, Freeman JR, Connell G, Spirito A, Boyer E, Walton M, Guthrie K, Cunningham RM. A Depression Prevention Intervention for Adolescents in the Emergency Department. J Adolesc Health 2016; 59:401-10. [PMID: 27267141 PMCID: PMC5035565 DOI: 10.1016/j.jadohealth.2016.04.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 04/06/2016] [Accepted: 04/06/2016] [Indexed: 12/11/2022]
Abstract
PURPOSE To evaluate acceptability and feasibility of a theoretically based two-part (brief in-person + 8-week automated text message) depression prevention program, "intervention for DepressiOn and Violence prevention in the Emergency department" (iDOVE), for high-risk adolescents. METHODS English-speaking emergency department (ED) patients (age 13-17, any chief complaint) were sequentially approached for consent on a convenience sample of shifts and screened for inclusion based on current depressive symptoms and past-year violence. After consent, baseline assessments were obtained; all participants were enrolled in the two-part intervention (brief in-ED + 8-week two-way text messaging). At 8 weeks, quantitative and qualitative follow-up assessments were obtained. Measures included feasibility, acceptability, and preliminary data on efficacy. Qualitative data were transcribed verbatim, double coded, and interpreted using thematic analysis. Quantitative results were analyzed descriptively and with paired t tests. RESULTS As planned, 16 participants (eight each gender) were recruited (75% of those who were eligible; 66% nonwhite, 63% low income, mean age 15.4). The intervention had high feasibility and acceptability: 93.8% completed 8-week follow-up; 80% of daily text messages received responses; 31% of participants requested ≥1 "on-demand" text message. In-person and text message portions were rated as good/excellent by 87%. Qualitatively, participants articulated: (1) iDOVE was welcome and helpful, if unexpected in the ED; (2) the daily text message mood assessment was "most important"; (3) content was "uplifting"; and (4) balancing intervention "relatability" and automation was challenging. Participants' mean ΔBDI-2 (Beck Depression Inventory) from baseline to 8-week follow-up was -4.9, (p = .02). CONCLUSIONS This automated preventive text message intervention is acceptable and feasible. Qualitative data emphasize the importance of creating positive, relevant, and interactive digital health tools for adolescents.
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Ranney ML, Patena JV, Nugent N, Spirito A, Boyer E, Zatzick D, Cunningham R. PTSD, cyberbullying and peer violence: prevalence and correlates among adolescent emergency department patients. Gen Hosp Psychiatry 2016; 39:32-8. [PMID: 26786845 PMCID: PMC4779373 DOI: 10.1016/j.genhosppsych.2015.12.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 12/04/2015] [Accepted: 12/11/2015] [Indexed: 01/16/2023]
Abstract
OBJECTIVE Posttraumatic stress disorder (PTSD) is often underdiagnosed and undertreated among adolescents. The objective of this analysis was to describe the prevalence and correlates of symptoms consistent with PTSD among adolescents presenting to an urban emergency department (ED). METHODS A cross-sectional survey of adolescents aged 13-17 years presenting to the ED for any reason was conducted between August 2013 and March 2014. Validated self-report measures were used to measure mental health symptoms, violence exposure and risky behaviors. Multivariate logistic regression analysis was performed to determine adjusted differences in associations between symptoms consistent with PTSD and predicted correlates. RESULTS Of 353 adolescents, 23.2% reported current symptoms consistent with PTSD, 13.9% had moderate or higher depressive symptoms and 11.3% reported past-year suicidal ideation. Adolescents commonly reported physical peer violence (46.5%), cyberbullying (46.7%) and exposure to community violence (58.9%). On multivariate logistic regression, physical peer violence, cyberbullying victimization, exposure to community violence, female gender and alcohol or other drug use positively correlated with symptoms consistent with PTSD. CONCLUSIONS Among adolescents presenting to the ED for any reason, symptoms consistent with PTSD, depressive symptoms, physical peer violence, cyberbullying and community violence exposure are common and interrelated. Greater attention to PTSD, both disorder and symptom levels, and its cooccurring risk factors is needed.
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McMANUS DD, Chong JW, Soni A, Saczynski JS, Esa N, Napolitano C, Darling CE, Boyer E, Rosen RK, Floyd KC, Chon KH. PULSE-SMART: Pulse-Based Arrhythmia Discrimination Using a Novel Smartphone Application. J Cardiovasc Electrophysiol 2015; 27:51-7. [PMID: 26391728 DOI: 10.1111/jce.12842] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 08/15/2015] [Accepted: 08/25/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Atrial fibrillation (AF) is a common and dangerous rhythm abnormality. Smartphones are increasingly used for mobile health applications by older patients at risk for AF and may be useful for AF screening. OBJECTIVES To test whether an enhanced smartphone app for AF detection can discriminate between sinus rhythm (SR), AF, premature atrial contractions (PACs), and premature ventricular contractions (PVCs). METHODS We analyzed two hundred and nineteen 2-minute pulse recordings from 121 participants with AF (n = 98), PACs (n = 15), or PVCs (n = 15) using an iPhone 4S. We obtained pulsatile time series recordings in 91 participants after successful cardioversion to sinus rhythm from preexisting AF. The PULSE-SMART app conducted pulse analysis using 3 methods (Root Mean Square of Successive RR Differences; Shannon Entropy; Poincare plot). We examined the sensitivity, specificity, and predictive accuracy of the app for AF, PAC, and PVC discrimination from sinus rhythm using the 12-lead EKG or 3-lead telemetry as the gold standard. We also administered a brief usability questionnaire to a subgroup (n = 65) of app users. RESULTS The smartphone-based app demonstrated excellent sensitivity (0.970), specificity (0.935), and accuracy (0.951) for real-time identification of an irregular pulse during AF. The app also showed good accuracy for PAC (0.955) and PVC discrimination (0.960). The vast majority of surveyed app users (83%) reported that it was "useful" and "not complex" to use. CONCLUSION A smartphone app can accurately discriminate pulse recordings during AF from sinus rhythm, PACs, and PVCs.
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Atiama-Nurbel T, Quilici S, Boyer E, Deguine JP, Glenac S, Bialecki A. Volatile Constituents of Cucumis sativus: Differences Between Five Tropical Cultivars. Chem Nat Compd 2015. [DOI: 10.1007/s10600-015-1408-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Berta E, Atallah I, Reyt E, Boyer E, Karkas A, Righini CA. The role of tonsillectomy in the initial diagnostic work-up of head and neck squamous cell carcinoma of unknown primary. Eur Ann Otorhinolaryngol Head Neck Dis 2014; 131:305-8. [DOI: 10.1016/j.anorl.2014.03.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 01/21/2014] [Accepted: 03/04/2014] [Indexed: 10/24/2022]
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Roby-Brami A, Van Zandt-Escobar A, Jarrassé N, Robertson J, Schnell N, Boyer E, Rasamimanana N, Hanneton S, Bevilacqua F. Toward the use of augmented auditory feedback for the rehabilitation of arm movements in stroke patients. Ann Phys Rehabil Med 2014. [DOI: 10.1016/j.rehab.2014.03.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Ward J, Szabo G, McManus D, Boyer E. Advanced molecular biologic techniques in toxicologic disease. J Med Toxicol 2012; 7:288-94. [PMID: 22072091 DOI: 10.1007/s13181-011-0189-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The advancement of molecular biologic techniques and their capabilities to answer questions pertaining to mechanisms of pathophysiologic events have greatly expanded over the past few years. In particular, these opportunities have provided researchers and clinicians alike the framework from with which to answer clinical questions not amenable for elucidation using previous, more antiquated methods. Utilizing extremely small molecules, namely microRNA, DNA, protein, and nanoparticles, we discuss the background and utility of these approaches to the progressive, practicing physician. Finally, we consider the application of these tools employed as future bedside point of care tests, aiding in the ultimate goal of unsurpassed patient care.
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Levine M, Curry SC, Ruha AM, Pizon AF, Boyer E, Burns J, Bikin D, Gerkin RD. Ethylene glycol elimination kinetics and outcomes in patients managed without hemodialysis. Ann Emerg Med 2012; 59:527-31. [PMID: 22226175 DOI: 10.1016/j.annemergmed.2011.12.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 11/20/2011] [Accepted: 12/02/2011] [Indexed: 10/14/2022]
Abstract
STUDY OBJECTIVE Ethylene glycol remains an important toxic cause of metabolic acidosis and acute renal failure. Traditionally, inhibition of alcohol dehydrogenase along with hemodialysis has been used for treatment. Because of reported long elimination half-life of ethylene glycol during alcohol dehydrogenase inhibition, hemodialysis has been used in patients who are otherwise doing well to clear ethylene glycol. We study ethylene glycol elimination kinetics in patients treated with fomepizole, but without hemodialysis. METHODS This was a retrospective, multicenter cohort study of patients older than 15 years who were treated at one of 3 medical centers during an 8-year period. Inclusion criteria were peak serum ethylene glycol concentration greater than 20 mg/dL, lack of renal failure on admission, treatment with fomepizole but without hemodialysis, and availability of serial serum ethylene glycol concentrations, allowing calculation of elimination half-life. The primary outcome variable was ethylene glycol elimination half-life; mortality and onset of renal failure were secondary outcome variables. RESULTS During the study period, 85 patients were treated for ethylene glycol toxicity, of whom 40 met inclusion criteria. The mean serum ethylene glycol elimination half-life was 14.2 hours (SD=3.7 hours; 95% confidence interval 13.1 to 15.3 hours). One patient presented with metabolic acidosis on admission and developed mild transient renal insufficiency but did not require hemodialysis. No patient died. CONCLUSION The mean elimination half-life of ethylene glycol in this population was shorter than previously reported without hemodialysis, and this select group of patients did well without enhanced elimination by hemodialysis.
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Ward J, Rhyee S, Plansky J, Boyer E. Methoxetamine: a novel ketamine analog and growing health-care concern. Clin Toxicol (Phila) 2011; 49:874-5. [PMID: 21981756 DOI: 10.3109/15563650.2011.617310] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Abar B, Baumann BM, Rosenbaum C, Boyer E, Boudreaux ED. Readiness to change alcohol and illicit drug use among a sample of emergency department patients. JOURNAL OF SUBSTANCE USE 2011. [DOI: 10.3109/14659891.2011.580413] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Abar B, Baumann BM, Rosenbaum C, Boyer E, Ziedonis D, Boudreaux ED. Profiles of importance, readiness and confidence in quitting tobacco use. JOURNAL OF SUBSTANCE USE 2011; 18:75-81. [PMID: 26097430 DOI: 10.3109/14659891.2011.606351] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE This study examined whether rulers of importance, readiness and confidence (IRC) in quitting smoking could be used to identify subgroups of smokers, with the future goal of potentially tailoring interventions to specific readiness profiles. METHODS Consecutive emergency department patients ≥18 years old were considered for enrolment. Participants provided information on their tobacco use and motivation to quit smoking using 10-point IRC rulers. We used latent profile analysis on the IRC rulers to identify subgroups of smokers and examined associations between profile membership and participant's nicotine dependence and demographics. RESULTS A total of 1549 patients were screened, yielding a sample of 609 tobacco users. According to statistical fit indices, a four-profile solution fits best: 32% displayed maximum importance and readiness with strong confidence, 43% of the sample displayed relatively average levels of all three variables, 17% displayed below average importance with least favourable readiness and confidence and 7% displayed least favourable importance and readiness but relatively high confidence. Profiles were then shown to differ on nicotine dependence and educational level. CONCLUSIONS Four distinct profiles of IRC responses were observed. Identifying and describing these patterns has the potential to enhance future targeted intervention efforts and has implications for theory development.
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Wachholtz A, Gonzalez G, Boyer E, Naqvi ZN, Rosenbaum C, Ziedonis D. Intersection of chronic pain treatment and opioid analgesic misuse: causes, treatments, and policy strategies. Subst Abuse Rehabil 2011; 2:145-62. [PMID: 24474854 PMCID: PMC3846312 DOI: 10.2147/sar.s12944] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Treating chronic pain in the context of opioid misuse can be very challenging. This paper explores the epidemiology and potential treatments for chronic pain and opioid misuse and identifies educational and regulation changes that may reduce diversion of opioid analgesics. We cover the epidemiology of chronic pain and aberrant opioid behaviors, psychosocial influences on pain, pharmacological treatments, psychological treatments, and social treatments, as well as educational and regulatory efforts being made to reduce the diversion of prescription opioids. There are a number of ongoing challenges in treating chronic pain and opioid misuse, and more research is needed to provide strong, integrated, and empirically validated treatments to reduce opioid misuse in the context of chronic pain.
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Vitale C, George M, Sheroff A, Hernon C, Boyer E. Tracheal and bronchial obstruction following cyanoacrylate aspiration in a toddler. Clin Toxicol (Phila) 2009; 46:560-2. [DOI: 10.1080/15563650701644303] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Courtney J, Boyer E. Case files of the University of Massachusetts fellowship in medical toxicology: lethal dose of opioids contained in an elastomeric capsule labeled as vancomycin. J Med Toxicol 2008; 4:192-6. [PMID: 18821494 DOI: 10.1007/bf03161200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
UNLABELLED A 67 year-old male presented to the emergency department with alteration in mental status. On arrival he had vital signs: pulse 110, BP 173/83, respiratory rate 4, oxygen saturation 57% and temperature 36.1 degrees Celsius. His past medical history included hypertension, vitamin B12 deficiency, hyperlipidemia, and recurrent cellulitis treated with vancomycin. The patient had no response to noxious stimuli, pinpoint pupils, and agonal respirations. Secondary to his wife's vehement denial that he had access to or history of using any narcotics, he was intubated after 2.2mg IV naloxone failed to reverse respiratory depression. Thirty minutes before presentation, however, he had received an intravenous infusion of vancomycin administered by his wife at home. The vancomycin, obtained from a home infusion medication supply company, was contained in one of five sealed elastomeric capsules delivered earlier that day. A qualitative comprehensive toxicology screen of urine for 1043 substances identified morphine, codeine, naloxone, lidocaine and caffeine. The original elastomeric container was not available for testing, but another container from the same delivery was submitted for testing to the state forensic laboratory. This intact container was labeled as Vancomycin 1g in 240mL of normal saline. The forensic laboratory confirmed that the alkaloidal contents of the elastomeric capsule were 10% codeine, 4.4% 6-monoacetyl morphine, and 84% morphine. No vancomycin was identified in the infusion bottles. The case was referred to the local police department and the state department of health drug control board. The home infusion company was also immediately notified to prevent similar occurrence. CONCLUSION We are reporting the first known case of opioid overdose from an adulterated elastomeric capsule that was labeled as containing an antimicrobial agent.
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Roux F, Boyer E, Jaulhac B, Dernis E, Closs-Prophette F, Puéchal X. Lyme meningoradiculitis: prospective evaluation of biological diagnosis methods. Eur J Clin Microbiol Infect Dis 2007; 26:685-93. [PMID: 17629757 DOI: 10.1007/s10096-007-0347-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The symptoms of Lyme meningoradiculitis and the value of biological examinations in an endemic area were determined in a prospective study in which data were collected on all patients consecutively hospitalised for Lyme meningoradiculitis at our institution during an 18-month period. Specific antibody titres in the serum and cerebrospinal fluid (CSF) were determined by Vidas enzyme-linked-immunosorbent-assay (IgG + IgM), Dade-Behring enzyme immunoassay (EIA) (IgM; IgG) and Western blot analysis (IgG). We also searched for Borrelia burgdorferi in the CSF by PCR analysis and following culture on a specific medium. A control group was recruited, consisting of 16 consecutive patients who had been referred during the same period with suspected but not confirmed Lyme meningoradiculitis. Eleven patients were included. Borrelia EIA of the serum revealed that 40% of the patients had both elevated specific IgM titres and intrathecal synthesis of specific IgG; 40% of the patients was negative for IgM but had isolated intrathecal synthesis of IgG; 20% of the patients had elevated specific IgM titres without intrathecal synthesis of IgG. PCR analysis and the CSF culture were positive in one case only (B. garinii). The results of this study highlight the importance of systematic serological testing for B. burgdorferi in the CSF in the case of early neuroborreliosis suspicion, even in the absence of IgM serum antibodies, which was the case in 40% of the patients in the present study. Nevertheless, intrathecal anti-B. burgdorferi IgG synthesis, which remains the "gold standard" for the diagnosis of neuroborreliosis, was not detectable in 20% of the patients for whom diagnosis was subsequently confirmed by demonstration of specific serum IgM.
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Levine MD, Boyer E. Hyperinsulinemia-euglycemia therapy: a useful tool in treating calcium channel blocker poisoning. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2006; 10:149. [PMID: 16879723 PMCID: PMC1751009 DOI: 10.1186/cc4964] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Hyperinsulinemia-euglycemia (HIE) therapy, when initiated promptly and aggressively, may offer considerable advantages in the treatment of calcium channel blocker poisoning. Although its mechanism of action is uncertain, HIE improves the efficiency with which the poisoned myocardium uses metabolic fuel, the end result of which is improvements in inotropy and other cardiovascular parameters. Although HIE is not universally accepted, the reports included in the previous issue of Critical Care should prompt clinicians to consider HIE an appropriate therapy specifically for calcium channel blocker poisoning.
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Abstract
Herbs and dietary supplements (HDS) are in widespread use in the United States, and are especially prevalent among chronically ill patients. This population is more likely to be admitted to health care facilities where they may continue to use HDS. The risk of adverse effects from HDS used during admission places significant liability on clinicians and hospitals. We describe the response of health care facilities in the Boston, Massachusetts area to this problem, and propose elements of a hospital policy which increases patient safety and satisfaction and minimizes the likelihood for adverse effects from HDS.
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Roblot F, Le Moal G, Godet C, Hutin P, Texereau M, Boyer E, Prazuck T, Lacroix C, Souala MF, Raffi F, Weinbreck P, Besnier JM, Garo B, de Gentile L, Becq-Giraudon B. Pneumocystis carinii pneumonia in patients with hematologic malignancies: a descriptive study. J Infect 2003; 47:19-27. [PMID: 12850158 DOI: 10.1016/s0163-4453(03)00038-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Objectives. A retrospective multicentric study was conducted over a five-year period to evaluate the clinical and laboratory characteristics and outcome of patients with proven Pneumocystis carinii pneumonia (PCP) complicating hematologic malignancies.Results. The study included 60 HIV-negative patients with 18 non-Hodgkin's malignant lymphoma (30%), 13 chronic lymphocytic leukaemia (21.7%), 10 acute leukemia (16.6%), 5 multiple myeloma (8.3%), 4 Waldenström's diseases (6.6%), 4 chronic myeloid leukemia (6.6%), 3 myelodysplasia (5%), 2 Hodgkin's diseases (3.3%) and 1 thrombopenia. Bronchoalveolar lavage was diagnostic in all patients. Forty-nine patients received cytotoxic drugs (81.7%), 25 (41.7%) a long-term corticotherapy and 15 (25%) underwent bone marrow transplantation. Twenty-seven patients (45%) required admission in the intensive care unit, 35 (58.3%) received an adjunctive corticotherapy and 18 mechanical ventilation (30%). Twenty patients (33.3%) died of PCP. A previous long-term corticotherapy (p=0.04), high respiratory (p=0.05) and pulse rates (p=0.02), elevated C reactive protein (p=0.01) and mechanical ventilation (OR=13.37; IC: 1.9-50) were associated with a poor prognosis. Adjunctive corticotherapy did not modify the prognosis.Conclusions. These results suggest that PCP can occur during the course of various hematologic malignancies, not only lymphoproliferative disorders. Prognosis remains poor. The diagnosis should be advocated more frequently and earlier to improve the prognosis.
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Boyer E, Bergevin I, Malo D, Gros P, Cellier MFM. Acquisition of Mn(II) in addition to Fe(II) is required for full virulence of Salmonella enterica serovar Typhimurium. Infect Immun 2002; 70:6032-42. [PMID: 12379679 PMCID: PMC130432 DOI: 10.1128/iai.70.11.6032-6042.2002] [Citation(s) in RCA: 190] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2001] [Revised: 12/18/2001] [Accepted: 07/05/2002] [Indexed: 01/01/2023] Open
Abstract
The roles of the genes feoB (ABC ferrous iron transporter), mntH (proton-dependent manganese transporter), and sitABCD (putative ABC iron and/or manganese transporter) in Salmonella pathogenicity were investigated by using mutant strains deficient in one, two, or three transporters. Our results indicated that sitABCD encodes an important transporter of Mn(II) and Fe(II) which is required for full virulence in susceptible animals (Nramp1(-/-)) and for replication inside Nramp1(-/-) macrophages in vitro. The mntH sitABCD double mutant (mutant MS) showed minimal Mn(II) uptake and increased sensitivity to H(2)O(2) and to the divalent metal chelator 2,2'-dipyridyl (DP) and was defective for replication in macrophages. In vivo MS appeared to be as virulent as the sitABCD mutant in Nramp1(-/-) animals. The ferrous iron transporter Feo was required for full virulence in 129/Sv Nramp1(-/-) mice, and infection with multiple mutants lacking FeoB was not fatal. The sitABCD feoB mutant (mutant SF) and the mntH sitABCD feoB mutant (mutant MSF) showed minimal Fe(II) uptake and were slightly impaired for replication in susceptible macrophages. MSF showed reduced growth in minimal medium deficient in divalent cations. The role of the mntH gene, which is homologous to mammalian Nramp genes, was also investigated after overexpression in the double mutant MS. MntH preferred Mn(II) over Fe(II) and could suppress MS sensitivity to H(2)O(2) and to DP, and it also improved the intracellular survival in Nramp1(-/-) macrophages. This study indicates that acquisition of Mn(II), in addition to Fe(II), is required for intracellular survival and replication of Salmonella enterica serovar Typhimurium in macrophages in vitro and for virulence in vivo.
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Martin PK, Bao Y, Boyer E, Winterberg KM, McDowell L, Schmid MB, Buysse JM. Novel locus required for expression of high-level macrolide-lincosamide-streptogramin B resistance in Staphylococcus aureus. J Bacteriol 2002; 184:5810-3. [PMID: 12270841 PMCID: PMC139611 DOI: 10.1128/jb.184.20.5810-5813.2002] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The yycF1(Ts) mutation in Staphylococcus aureus conferred hypersensitivity to macrolide-lincosamide-streptogramin B (MLS(B)) antibiotics on strains either containing or lacking ermB. The overexpression of the S. aureus Ssa protein restored the yycF1 mutant to wild-type levels of susceptibility. Inactivation of ssa in an unmutagenized strain dramatically reduced ermB-based resistance. Conditional loss of function or expression of ssa in the yycF1 mutant is proposed to result in the observed hypersensitivity to MLS(B) antibiotics.
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Abstract
The redox-active metals iron and manganese are required for energy metabolism, protection against oxidative stress and defense against infections. In eukaryotes, both divalent metals are transported by Nramp transporters. The sequence of these transporters was remarkably conserved during evolution. Several bacterial Nramp homologs (MntH) are also proton-dependent manganese transporters. Here, we present phylogenetic evidence for the polyphyletic origins of three groups of MntH proteins and for possible Nramp horizontal gene transfer with eukaryotes. We propose that the evolution of the MntH/Nramp family is related to adaptation to oxidative environments, including those arising during infection of animals and plants.
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Lomovskaya O, Lee A, Hoshino K, Ishida H, Mistry A, Warren MS, Boyer E, Chamberland S, Lee VJ. Use of a genetic approach to evaluate the consequences of inhibition of efflux pumps in Pseudomonas aeruginosa. Antimicrob Agents Chemother 1999; 43:1340-6. [PMID: 10348749 PMCID: PMC89275 DOI: 10.1128/aac.43.6.1340] [Citation(s) in RCA: 165] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Drug efflux pumps in Pseudomonas aeruginosa were evaluated as potential targets for antibacterial therapy. The potential effects of pump inhibition on susceptibility to fluoroquinolone antibiotics were studied with isogenic strains that overexpress or lack individual efflux pumps and that have various combinations of efflux- and target-mediated mutations. Deletions in three efflux pump operons were constructed. As expected, deletion of the MexAB-OprM efflux pump decreased resistance to fluoroquinolones in the wild-type P. aeruginosa (16-fold reduction for levofloxacin [LVX]) or in the strain that overexpressed mexAB-oprM operon (64-fold reduction for LVX). In addition to that, resistance to LVX was significantly reduced even for the strains carrying target mutations (64-fold for strains for which LVX MICs were >4 microg/ml). We also studied the frequencies of emergence of LVX-resistant variants from different deletion mutants and the wild-type strain. Deletion of individual pumps or pairs of the pumps did not significantly affect the frequency of emergence of resistant variants (at 4x the MIC for the wild-type strain) compared to that for the wild type (10(-6) to 10(-7)). In the case of the strain with a triple deletion, the frequency of spontaneous mutants was undetectable (<10(-11)). In summary, inhibition of drug efflux pumps would (i) significantly decrease the level of intrinsic resistance, (ii) reverse acquired resistance, and (iii) result in a decreased frequency of emergence of P. aeruginosa strains highly resistant to fluoroquinolones in clinical settings.
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Lemerle E, Bastien M, Demolliens-Dreux G, Forest JL, Boyer E, Chabasse D, Célérier P. [Cutaneous Scedosporium infection revealed by bullous-necrotic purpura]. Ann Dermatol Venereol 1998; 125:711-4. [PMID: 9835962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
BACKGROUND Non-mycetomatous cutaneous scedosprium is an uncommon mycosis observed in immunodepressed subjects. We report a case with an inaugural presentation of bullous and necrotic purpura. CASE REPORT A 79-year-old man on intermittent corticosteroid therapy for bronchospasm was admitted for bullous and necrotic purpura and fever. Subcutaneous nodules with a sporotrichoid aspect developed despite wide-spectrum antibiotics. Microbiology samples cultured on Sabouraud medium evidenced Scedosporium apiospermum. The pathogenic nature of the infection was proven on a skin biopsy showing numerous myceleal filaments with Gomori-Grocott staining despite negative PAS. No pulmonary involvement was evidenced. The patient was treated unsuccessfully with itraconazole. A Pseudomonas lung infection was fatal. DISCUSSION Scedosporium apiospermum, an ubiquitous ascomycetes anamorphous to Pseudallescheria boydii, is the cause of a growing number of human infections due to widespread use of immunosuppressors. Skin and lung localizations predominate. The inaugural bullous and necrotic purpural skin manifestations in this case are unusual. In addition, the patient was only minimally immunodepressed and despite demonstrated in vitro sensitivity, itraconazole was ineffective clinically. Treatment is not well defined, but surgery is essential in combination with empirically chosen antifungals.
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Eastman PS, Mittler J, Kelso R, Gee C, Boyer E, Kolberg J, Urdea M, Leonard JM, Norbeck DW, Mo H, Markowitz M. Genotypic changes in human immunodeficiency virus type 1 associated with loss of suppression of plasma viral RNA levels in subjects treated with ritonavir (Norvir) monotherapy. J Virol 1998; 72:5154-64. [PMID: 9573287 PMCID: PMC110088 DOI: 10.1128/jvi.72.6.5154-5164.1998] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Ten subjects received 600 to 1,200 mg of the human immunodeficiency virus type 1 (HIV-1) protease inhibitor ritonavir per day. Following 2 weeks of therapy, plasma HIV RNA levels decreased by a mean of 1. 57 (range, 0.89 to 1.96) log units. With continued therapy, HIV RNA levels began to rise in eight subjects. The initial rise in plasma RNA levels was temporally associated with the development and quantitative increase in the V82 resistance mutation. Doubling times of the V82A mutant virus were estimated to be 2.4 to 4.8 days. An L63P/A mutation was commonly present at baseline even in subjects with a durable virologic response. The concomitant acquisition of an L63P/A mutation with the V82A/F mutation at the time when plasma RNA levels rebounded suggests a role for the L63P/A mutation in improving the fitness of the V82A/F mutation. Subsequent additional genotypic changes at codons 54 and 84 were often associated with further increases in plasma RNA levels. Ongoing viral replication in the presence of drugs resulted in the appearance of additional genotypic changes, including the L90M saquinavir resistance mutation, and decreased phenotypic susceptibility. The relative fitness of the protease V82A ritonavir resistance mutation and reverse transcriptase T215Y/F zidovudine resistance mutation following drug withdrawal were estimated to be 96 to 98% that of the wild type. Durability of the virologic response was associated with plasma RNA levels at the nadir. A virologic response beyond 60 days was not observed unless plasma HIV RNA levels were suppressed below 2,000 copies/ml, consistent with estimates from V82A doubling times for selection of a single resistance mutation to dominate the replicating population.
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