Polycyclic aromatic hydrocarbons (PAHs) are a large group of organic compounds comprised of two or more fused benzene rings arranged in various configurations. PAHs are widespread environmental ...contaminants formed as a result of incomplete combustion of organic materials such as fossil fuels. The occurrence of PAHs in ambient air is an increasing concern because of their carcinogenicity and mutagenicity. Although emissions and allowable concentrations of PAHs in air are now regulated, the health risk posed by PAH exposure suggests a continuing need for their control through air quality management. In light of the environmental significance of PAH exposure, this review offers an overview of PAH properties, fates, transformations, human exposure, and health effects (acute and chronic) associated with their emission to the atmosphere. Biomarkers of PAH exposure and their significance are also discussed.
Psychogenic non-epileptic seizures (PNES) are common in neurological settings and often associated with considerable distress and disability. The psychological mechanisms underlying PNES are poorly ...understood and there is a lack of well-established, evidence-based treatments. This paper advances our understanding of PNES by providing a comprehensive systematic review of the evidence pertaining to the main theoretical models of this phenomenon. Methodological quality appraisal and effect size calculation were conducted on one hundred forty empirical studies on the following aspects of PNES: life adversity, dissociation, anxiety, suggestibility, attentional dysfunction, family/relationship problems, insecure attachment, defence mechanisms, somatization/conversion, coping, emotion regulation, alexithymia, emotional processing, symptom modelling, learning and expectancy. Although most of the studies were only of low to moderate quality, some findings are sufficiently consistent to warrant tentative conclusions: (i) physical symptom reporting is elevated in patients with PNES; (ii) trait dissociation and exposure to traumatic events are common but not inevitable correlates of PNES; (iii) there is a mismatch between subjective reports of anxiety and physical arousal during PNES; and (iv) inconsistent findings in this area are likely to be attributable to the heterogeneity of patients with PNES. Empirical, theoretical and clinical implications are discussed.
•The quality of evidence on the psychology/psychiatry of PNES is low to moderate.•The evidence for most theories of PNES is limited and often inconsistent.•Increased physical symptom reporting is a consistent correlate of PNES.•There is a mismatch between subjective anxiety and physical arousal during PNES.•Future research needs to accommodate the heterogeneity of patients with PNES.
Psychogenic Nonepileptic Seizures (PNES) superficially resemble epileptic seizures but are thought to have a psychological rather than epileptic basis. Patients with PNES vary widely in terms of ...background, personality profiles, comorbidities, response to treatment and outcomes. Previous accounts interpreting these seizures as the activation of dissociated material, a physical manifestation of emotional distress, hard-wired reflex responses, or learned behaviours cannot explain key features of the phenomenon. Drawing on a brief review of the literature on etiology, correlates and phenomenology of PNES, this paper integrates existing approaches and data within a novel explanatory framework that applies to all PNES patients with subjectively involuntary seizures. Following the Integrative Cognitive Model of medically unexplained symptoms, we suggest that the central feature of all PNES is the automatic activation of a mental representation of seizures (the “seizure scaffold”) in the context of a high level inhibitory processing dysfunction. This often arises in response to elevated autonomic arousal, and may disrupt the individual's awareness of distressing material, but can become divorced from abnormal autonomic and emotional activity. This model accounts both for existing findings and the heterogeneity of patients with PNES, whilst leading to a number of novel hypotheses against which it can be evaluated.
•Current models of PNES can account for some but not all of the available data.•Automatic activation of seizure representations in memory may be a unifying process.•Suppression of arousal and distress are typical maintaining factors for PNES.•Inhibitory dysfunction, often arising from chronic stress, is a key vulnerability.•Trauma exposure is common but neither necessary nor sufficient for PNES to occur.
Summary Most patients requiring midface reconstruction have had ablative surgery for malignant disease, and most require postoperative radiotherapy. This type of facial reconstruction attracts ...controversy, not only because of the many reconstructive options, but also because dental and facial prostheses can be very successful in selected cases. This Personal View is based on a new classification of the midface defect, which emphasises the increasing complexity of the problem. Low defects not involving the orbital adnexae can often be successfully treated with dental obturators. For the more extensive maxillary defects, there is consensus that a free flap is required. Composite flaps of bone and muscle harvested from the iliac crest with internal oblique or the scapula tip with latissimus dorsi can more reliably support the orbit and cheek than soft-tissue free flaps and non-vascularised grafts, and also enable an implant-borne dental or orbital prosthesis. Nasomaxillary defects usually require bone to augment the loss of the nasal bones, but orbitomaxillary cases can be managed more simply with local or soft-tissue free flaps. We review the current options and our own experience over the past 15 years in an attempt to rationalise the management of these defects.
Background. Nontuberculous mycobacteria (NTM) commonly colonize municipal water supplies and cause healthcare-associated outbreaks. We investigated a biphasic outbreak of Mycobacterium abscessus at a ...tertiary care hospital. Methods. Case patients had recent hospital exposure and laboratory-confirmed colonization or infection with M. abscessus from January 2013 through December 2015. We conducted a multidisciplinary epidemiologic, field, and laboratory investigation. Results. The incidence rate of M. abscessus increased from 0.7 cases per 10 000 patient-days during the baseline period (January 2013–July 2013) to 3.0 cases per 10 000 patient-days during phase 1 of the outbreak (August 2013–May 2014) (incidence rate ratio, 4.6 95% confidence interval, 2.3–8.8; P < .001). Thirty-six of 71 (51%) phase 1 cases were lung transplant patients with positive respiratory cultures. We eliminated tap water exposure to the aerodigestive tract among high-risk patients, and the incidence rate decreased to baseline. Twelve of 24 (50%) phase 2 (December 2014–June 2015) cases occurred in cardiac surgery patients with invasive infections. Phase 2 resolved after we implemented an intensified disinfection protocol and used sterile water for heater-cooler units of cardiopulmonary bypass machines. Molecular fingerprinting of clinical isolates identified 2 clonal strains of M. abscessus; 1 clone was isolated from water sources at a new hospital addition. We made several water engineering interventions to improve water flow and increase disinfectant levels. Conclusions. We investigated and mitigated a 2-phase clonal outbreak of M. abscessus linked to hospital tap water. Healthcare facilities with endemic NTM should consider similar tap water avoidance and engineering strategies to decrease risk of NTM infection.
Symptoms and the body: Taking the inferential leap Van den Bergh, Omer; Witthöft, Michael; Petersen, Sibylle ...
Neuroscience & biobehavioral reviews/Neuroscience and biobehavioral reviews,
March 2017, 2017-Mar, 2017-03-00, 20170301, Letnik:
74, Številka:
Pt A
Journal Article
Recenzirano
Odprti dostop
•The experience of physical symptoms is related to physiological dysfunction in a highly variable way.•Using a predictive coding framework we propose a new model of the body-symptom relationship.•We ...describe critical conditions influencing the body-symptom correspondence.•Theoretical and clinical implications of this new account are explored.
The relationship between the conscious experience of physical symptoms and indicators of objective physiological dysfunction is highly variable and depends on characteristics of the person, the context and their interaction. This relationship often breaks down entirely in the case of “medically unexplained” or functional somatic symptoms, violating the basic assumption in medicine that physical symptoms have physiological causes. In this paper, we describe the prevailing theoretical approach to this problem and review the evidence pertaining to it. We then use the framework of predictive coding to propose a new and more comprehensive model of the body-symptom relationship that integrates existing concepts within a unifying framework that addresses many of the shortcomings of current theory. We describe the conditions under which a close correspondence between the experience of symptoms and objective physiology might be expected, and when they are likely to diverge. We conclude by exploring some theoretical and clinical implications of this new account.
BACKGROUND There is no large study validating the appropriateness of current treatment guidelines for Mycobacterium avium complex (MAC) lung disease. This is a retrospective single-center review ...evaluating the efficacy of macrolide/azalide-containing regimens for nodular/bronchiectatic (NB) MAC lung disease. METHODS Patients were treated according to contemporary guidelines with evaluation of microbiologic responses. Macrolide susceptibility of MAC isolates was done at initiation of therapy, 6 to 12 months during therapy, and on the first microbiologic recurrence isolate. Microbiologic recurrence isolates also underwent genotyping for comparison with the original isolates. RESULTS One hundred eighty patients completed > 12 months of macrolide/azalide multidrug therapy. Sputum conversion to culture negative occurred in 154 of 180 patients (86%). There were no differences in response between clarithromycin or azithromycin regimens. Treatment regimen modification occurred more frequently with daily (24 of 30 80%) vs intermittent (2 of 180 1%) therapy ( P = .0001). No patient developed macrolide resistance during treatment. Microbiologic recurrences during therapy occurred in 14% of patients: 73% with reinfection MAC isolates, 27% with true relapse isolates ( P = .03). Overall, treatment success (ie, sputum conversion without true microbiologic relapse) was achieved in 84% of patients. Microbiologic recurrences occurred in 74 of 155 patients (48%) after completion of therapy: 75% reinfection isolates, 25% true relapse isolates. CONCLUSIONS Current guidelines for macrolide/azalide-based therapies for NB MAC lung disease result in favorable microbiologic outcomes for most patients without promotion of macrolide resistance. Intermittent therapy is effective and significantly better tolerated than daily therapy. Microbiologic recurrences during or after therapy are common and most often due to reinfection MAC genotypes.
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