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Loud Noise (loud + noise)

Distribution by Scientific Domains

Medical Sciences	80%

Selected Abstracts

Loud noise enhances nigrostriatal dopamine toxicity induced by MDMA in mice

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 4 2004
Marco Gesi
Abstract The neurotoxicity of 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) has been intensely investigated due to the widespread abuse of this drug and its neurotoxic effects. In mice, MDMA neurotoxicity has been demonstrated for striatal dopamine (DA) terminals. However, the current literature has reported great variability in the effects induced by MDMA; this is partially due to changes in environmental conditions. For instance, elevated temperature and a crowded noisy environment markedly increase the neurotoxic effects induced by MDMA. The environmental factor loud noise is often present during ecstasy intake; however, only a few studies have analysed the consequence of a concomitant exposure to loud noise and ecstasy intake. In the present experimental work, we investigated whether nigrostriatal DA toxicity occurring after MDMA administration was potentiated in the presence of loud noise (100 dBA). We administered MDMA to C57/Black mice using a "binging" pattern for two durations of white noise exposure. We found a marked enhancement of MDMA toxicity (7.5 mg/Kg ×4, 2 hours apart, i.p.) in the presence of white noise exposure lasting for at least 6 hours. The striatal damage was assessed by assaying DA levels as well as the loss of tyrosine hydroxylase (TH) and the increase in striatal glial fibrillary acidic protein (GFAP) immunohistochemistry. Since loud noise often accompanies ecstasy intake, the present findings call for more in-depth studies aimed at disclosing the fine mechanisms underlying this enhancement. Microsc. Res. Tech. 64:297,303, 2004. © 2004 Wiley-Liss, Inc. [source]

Age- and Genotype-Specific Triggers for Life-Threatening Arrhythmia in the Genotyped Long QT Syndrome

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 8 2008
TOMOKO SAKAGUCHI M.D.
Introduction: Patients with long QT syndrome (LQTS) become symptomatic in adolescence, but some become at age of ,20 years. Since it remains unknown whether clinical features of symptomatic LQTS patients differ depending on the age of onset, we aimed to examine whether triggers for cardiac events are different depending on the age in genotyped and symptomatic LQTS patients. Methods and Results: We identified 145 symptomatic LQTS patients, divided them into three groups according to the age of first onset of symptoms (young <20, intermediate 20,39, and older ,40 years), and analyzed triggers of cardiac events (ventricular tachycardia, syncope, or cardiac arrest). The triggers were divided into three categories: (1) adrenergically mediated triggers: exercise, emotional stress, loud noise, and arousal; (2) vagally mediated triggers: rest/sleep; and (3) secondary triggers: drugs, hypokalemia, and atrioventricular (AV) block. In the young group, 78% of the cardiac events were initiated by adrenergically mediated triggers and 22% were vagally mediated, but none by secondary triggers. In contrast, the adrenergically mediated triggers were significantly lower in the intermediate group. The percentage of secondary triggers was significantly larger in the older group than in the other two groups (0% in young vs 23% in intermediate vs 72% in older; P < 0.0001). Concerning the subdivision of secondary triggers on the basis of genotype, hypokalemia was only observed in LQT1, drugs mainly in LQT2, and AV block only in LQT2. Conclusion: Arrhythmic triggers in LQTS differ depending on the age of the patients, stressing the importance of age-related therapy for genotyped LQTS patients. [source]

Loud noise enhances nigrostriatal dopamine toxicity induced by MDMA in mice

Teen workers' exposures to occupational hazards and use of personal protective equipment

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 10 2008
Carol W. Runyan MPH
Abstract Background Prior research indicates that working adolescents seek care for the toxic effects of on-the-job chemical and environmental hazard exposures. Methods This cross-sectional survey of a nationally representative sample of 866 adolescent workers in the retail and service sector examines their exposures, personal protective equipment (PPE) use, and training. Results Two-thirds of respondents were exposed to continuous, very loud noise, 55% to thermal hazards and 54% to chemical hazards. Few teens reported using any PPE, though those who had been trained reported somewhat higher usage. Conclusions Teens working in the retail and service sectors experience a variety of chemical, thermal, biologic and noise exposures. Efforts to eradicate such exposures need to be complemented by increased provision of PPE and appropriate training in their use by employers. Am. J. Ind. Med. 51:735,740, 2008. Published 2008 Wiley-Liss, Inc. [source]

Longitudinal course of anxiety in children and adolescents with Williams syndrome,

AMERICAN JOURNAL OF MEDICAL GENETICS, Issue 2 2010
Janet Woodruff-Borden
Abstract The longitudinal course of anxiety disorders in 45 children and adolescents with Williams syndrome (WS) was examined. Children were ages 4,13 years at the initial assessment. To assess their child's DSM-IV diagnoses, parents completed a structured diagnostic interview 3,9 times at intervals of at least 1 year. At the first assessment, 60% of the sample presented with at least one anxiety diagnosis; 82.2% received an anxiety diagnosis at some time during the study. Chronic, persistent anxiety within the period 5 years after their initial diagnosis was shown by 62.2% of those with an anxiety diagnosis (51.1% of the entire sample). The most common diagnoses were specific phobias and generalized anxiety disorder. Multilevel logistic regression models were estimated for the presence of any anxiety disorder, specific phobia, and specific phobia of loud noises. Developmental trajectories, expressed as the probability of a positive diagnosis, suggested that the odds of a positive diagnosis did not change with age. IQ was not significantly related to the presence of an anxiety disorder. However, there was a significant relation between executive functioning and anxiety such that the presence of an anxiety diagnosis was associated with increased scores on behavioral regulation, indicative of increased difficulty with inhibitory control of affect and behavior. These findings are discussed in terms of persistence of anxiety over time and the need to develop and test interventions to address the high levels of anxiety experienced by children and adolescents with WS. © 2010 Wiley-Liss, Inc. [source]