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BACKGROUND: Alcohol septal ablation (ASA), is a well-established treatment for symptomatic hypertrophic obstructive cardiomyopathy (HOCM). We report the acute, short and long-term clinical and echocardiographic outcomes of our experience in a single Australian centre over 16 years. METHODS: We retrospectively analysed consecutive patients presenting to our centre for ASA between March 2000 and July 2016. Local databases were interrogated along with direct patient or physician contact occurred where required. RESULTS: Alcohol septal ablation was performed in 80 patients with symptomatic, medication refractory HOCM (mean age 61±15 years; range 22-84 years; 50% male). All patients had transthoracic echocardiography prior to the procedure, within 48hours of the procedure, 6 weeks, 6 months, 1 year and yearly thereafter to a median follow-up of 80±40months. At baseline, mean resting and provoked LVOT gradients were 80±49mmHg and 97±40mmHg respectively. Compared with baseline, ASA led to a reduction in resting LVOT gradients at all time points, particularly at 2 days-52±41mmHg, p<0.001; 12 months-29±34mmHg, p<0.001; and last follow-up 12±21mmHg, p<0.001. Provoked LVOT gradients were also reduced at 2 days-64±44mmHg and last follow-up of 19±29mmHg, p<0.001. Compared to baseline (19.8±4.2mm), ASA was associated with a reduction in interventricular septal (IVS) thickness at all time intervals with last echocardiographic follow-up at 80 months being 16.0±4.9mm, (
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Cateterismo Cardíaco/métodos , Cardiomiopatia Hipertrófica/cirurgia , Etanol/farmacologia , Septos Cardíacos/efeitos dos fármacos , Técnicas de Ablação , Adulto , Idoso , Idoso de 80 Anos ou mais , Cardiomiopatia Hipertrófica/terapia , Ecocardiografia , Eletrocardiografia , Feminino , Seguimentos , Septos Cardíacos/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Adulto JovemRESUMO
A 45-year-old male patient was admitted to the Regional Poison Center because of poisoning with dimethyloaniline contained in a toxic resin-curing dimethyl aniline-based formulation ingested inadvertently. Intoxication happened at workplace. The patient was then transferred to the Toxicology Clinic, where he stayed for 3 weeks. During the hospitalization, the primary method of treatment involved administration of methylene blue, which is the antidote of choice in such cases. During the intensive care and treatment of the patient massive intravascular hemolysis was seen. In that case treatment with blood products was required. He also showed signs of liver dysfunction due to cholestatic liver damage and jaundice. The reported case shows that severe organ damage may result from poisoning with even a small amount of the toxicant. Med Pr 2017;68(6):795-801.
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Acidentes de Trabalho , Compostos de Anilina/intoxicação , Metemoglobinemia/induzido quimicamente , Quelantes/uso terapêutico , Humanos , Masculino , Metemoglobinemia/tratamento farmacológico , Azul de Metileno/uso terapêutico , Pessoa de Meia-IdadeRESUMO
BACKGROUND: The standpoint published by the National Consultant in the Field of Occupational Medicine obliges physicians to send, to institutions responsible for traffic safety, the information on individuals who, for medical reasons, should not be permitted to drive motor vehicles. This situation is a source of a conflict: on the one hand the medical profession is a profession of public trust; on the other the doctor, when performing his/her official duties, is obliged to safeguard the wellbeing of the general population and, therefore, is expected to take suitable measures (including administrative) if he/she is in the possession of an information that something or someone may offer a threat to traffic safety. MATERIAL AND METHODS: On the basis of the existing legal regulations as well as author's own experiences, it has been attempted to standardize clinical and certifying procedures to be used in cases when an individual (a driver candidate or a current driver) is reasonably suspected to be encumbered with a characteristic that precludes him/her from being granted permission to drive motor vehicles. RESULTS: The authors of this publication developed and then implemented a standard clinical test procedure to be applied in circumstances as those described above. A statistical analysis of the implemented algorithm based on clinical cases hospitalized in 2008-2010 at the Nofer Institute of Occupational Medicine, Department of Occupational Diseases and Toxicology, Toxicology Unit (DODTTU) has been also performed. CONCLUSIONS: This paper reports the first attempt to implement, in a hospital ward, the algorithm intended to ensure comprehensive and honest procedure to be applied when institution responsible for issue and/ or re-confirming of driving licenses must be notified by a hospital ward worker to the concerned institution that the examined patient should not, for medical reasons, be permitted to
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Algoritmos , Condução de Veículo/legislação & jurisprudência , Licenciamento/legislação & jurisprudência , Licenciamento/normas , Notificação de Abuso , Humanos , Polônia , Responsabilidade SocialRESUMO
Metformin has been used for many years as oral anti-hyperglycaemic agent in the treatment of type 2 diabetes mellitus either in Poland or in the world. Metformin is the most commonly prescribed agent, but acute poisonings of this agent are rare. A review of our experience indicates, that poisoning with this agent may lead to life-threatening or fatal metformin toxicity. The authors of this publication postulate, that each patient with metformin exposure should be hospitalized. Physician must be vigilant to recognize anti-hyperglycaemic agent poisonings like biguanides when hypoglycaemia and acidosis are present in laboratory results. We present patients with metformin toxicity, some of them with fatal course.
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Overdose de Drogas/diagnóstico , Overdose de Drogas/terapia , Hipoglicemiantes/intoxicação , Metformina/intoxicação , Adulto , Idoso , Diabetes Mellitus Tipo 2/tratamento farmacológico , Evolução Fatal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , SuicídioRESUMO
Emphysematous gastritis is a rare condition historically associated with high mortality. It is characterised by gastric mural pneumatosis and portal venous gas, secondary to bacterial or fungal invasion. Given the rarity of the condition, there is little evidence to guide clinical decisions regarding whether a patient requires surgical resection. We describe the case of a 72-year-old male diagnosed with emphysematous gastritis, with endoscopic evidence of gastric fundus mucosal ischaemia. As there was no evidence of ischaemia extending to the serosa on exploratory laparotomy, gastrectomy was not performed, and the patient was managed conservatively. He subsequently made a full recovery, and was discharged without any further complications. This case demonstrates that in the absence of full-thickness gastric ischaemia, patients with emphysematous gastritis may be appropriate for conservative management without surgical resection.
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We present case a male patient who attempted suicide by ingestion of 90 tablets of digoxin in total dose of 22.5 mg. A measured peak level of digoxin was 6,75 ng/ml. Temporary invasive cardiac pacing with single chamber ventricular pacer was performed for treatment of the life-threatening rhythm and conduction disturbances that revealed within few hours after admission. According to the authors, presented method of therapy should always be taken into consideration in case development of cardiovascular disturbances in acute poisoning with digoxin.
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Arritmias Cardíacas/induzido quimicamente , Arritmias Cardíacas/terapia , Digoxina/intoxicação , Tentativa de Suicídio , Adulto , Estimulação Cardíaca Artificial , Overdose de Drogas , Humanos , MasculinoRESUMO
INTRODUCTION AND IMPORTANCE: Appendicitis within an incisional hernia is rare, with current literature describing a small number of cases, occurring through a variety of surgical incisions. We describe a case of appendicitis contained within an incisional hernia following reversal of a loop ileostomy, on a background of previous sigmoid cancer resection. This is the second such case we were able to identify on literature review. CASE PRESENTATION: A 45 year old man presented with one day of migratory abdominal pain, predominantly focused at a tender, irreducible lump in his right lower quadrant, underlying the scar from previous reversal of loop ileostomy. CT on admission revealed an incisional hernia, containing an inflamed appendiceal tip. He underwent an uncomplicated laparoscopic appendicectomy and primary suture closure of the hernia defect, and was discharged the following day. Acute appendicitis was confirmed on histopathology. DISCUSSION: Placement of a defunctioning ileostomy is common in the management of colonic cancers, and incisional hernias are a common complication. It is however rare for an appendix to be contained within a hernia sac, and even rarer for appendicitis to develop in this setting. As a result, the presentation of this condition may mimic that of an incarcerated or strangulated incisional hernia, with pre-operative diagnosis typically relying on diagnostic imaging. CONCLUSION: Incisional hernia appendicitis is rare and presents a diagnostic challenge. Early recognition of this dual pathology is necessary to allow for prompt surgical management of both the appendicitis and hernia, as well as guiding the approach for hernia repair.
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Administration of high-dose hydroxocobalamin, or vitamin B12, is an emerging, targeted rescue therapy for the treatment of refractory vasoplegic shock. This is an uncommon but potentially life-threatening complication following cardiac surgery and carries a poor prognosis, particularly when patients fail to respond to first-line therapy with catecholamine vasopressors. This study describes our experience in treating refractory vasodilatory shock following cardiac surgery with high-dose hydroxocobalamin. Administration of hydroxocobalamin in seven patients was associated with an improvement in mean arterial blood pressure or reduction in vasopressor requirements, which were both immediate and sustained throughout our observational period. No deaths or adverse effects attributable to hydroxocobalamin administration occurred in our cohort. Our observations show that high-dose hydroxocobalamin is a safe and effective rescue therapy in refractory vasoplegic shock post cardiopulmonary bypass (CPB).
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BACKGROUNDS: The COVID-19 pandemic presents ongoing challenges for healthcare. Stay at Home orders ('lockdowns') and community fears have been suggested to create reluctance to seek healthcare. We aimed to determine whether the rates of perforated appendicitis and negative appendicectomy have been affected by the pandemic, and to analyse the effect of lockdowns on the management of acute appendicitis in Victoria. METHODS: We conducted a retrospective audit of emergency appendicectomies performed under adult General Surgery units at Monash Health in Victoria from January 2019 to September 2021, including 242 days of lockdown. RESULTS: 2459 patients were included. Fewer patients had perforated appendicitis during the second lockdown (6.3% versus 10.7% baseline; p = 0.027). The rate of negative appendicectomy was reduced during the first lockdown (4.1% versus 14.9% baseline; p = 0.002) and during intervals between lockdown in 2021 (9.8%; p = 0.010). There was no difference in the rate of perforated appendicitis or negative appendicectomy at other times. Time to surgery and number of appendicectomies performed were also not significantly different. Fewer appendicectomies were performed after hours during lockdowns and in 2021 more generally compared to baseline (p < 0.05). CONCLUSION: The lower negative appendicectomy rate during the first lockdown may reflect increased pre-operative imaging or clinical observation for undifferentiated presentations. There was a reduction in perforated appendicitis during the second lockdown, and no significant difference at other times. Contrary to other studies, lockdowns associated with the COVID-19 pandemic may not create a reluctance to seek healthcare in all regions.
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Apendicite , COVID-19 , Doença Aguda , Adulto , Apendicectomia/métodos , Apendicite/epidemiologia , Apendicite/cirurgia , COVID-19/epidemiologia , Controle de Doenças Transmissíveis , Humanos , Pandemias/prevenção & controle , Estudos RetrospectivosRESUMO
Toxic liver injury poses an important heath problem in occupational medicine. Toxic response of this organ may arise from acute or chronic exposure to different substances. The final toxicological response to different toxicants may be defined as the regeneration of cells, loss of their function or necrosis. The morphology of toxic drug- or chemical-induced liver injury usuall differentiates into one of the following phenotypes: cholestatic injury, hepato- cellular injury, often associated with elevated l enzymes, mitochondrial injuries and delayed immunological injury. In this article, the authors present current knowledge of the pathogenesis of morphological changes in hepatocytes as the result of exposure to xenobiotics.
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Doença Hepática Induzida por Substâncias e Drogas/etiologia , Fígado/efeitos dos fármacos , Doenças Profissionais/induzido quimicamente , Doenças Profissionais/metabolismo , Exposição Ocupacional/efeitos adversos , Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Fígado Gorduroso/induzido quimicamente , Fígado Gorduroso/metabolismo , Humanos , Fígado/metabolismo , Microssomos Hepáticos/metabolismo , Mitocôndrias Hepáticas/metabolismo , Doenças Profissionais/prevenção & controle , Fatores de Risco , Xenobióticos/metabolismoRESUMO
Liver plays an important role in biological detoxication of xenobiotics. During this process, one can observe the inactivation and successful elimination of metabolites and toxic substances. The metabolic reactions responsible for detoxications include phases I and II. The phase I reactions increase polarity of xenobiotics through inserting new functional groups to xenobiotic molecules, while during phase II conjugation to endogenous hydrophilic molecules results in potent increase in polarity and water solubility. Phase III involves the transport process mediated by transmembranous transporter proteins, which remove a large number of xenobiotics from blood into liver. Oxidative stress and oxidation of lipids may lead to liver injury. Functional impairment of mitochondrial metabolism is associated with intensive production of reactive oxygen species. The underlying mechanisms during mitochondrial dysfunction may lead to cellular necrosis and apoptosis.
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Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Fígado/efeitos dos fármacos , Desintoxicação Metabólica Fase II , Desintoxicação Metabólica Fase I , Xenobióticos/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Humanos , Inativação Metabólica , Fígado/metabolismo , Microssomos Hepáticos/metabolismo , Mitocôndrias Hepáticas/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
OBJECTIVES: The primary aim of this work was to assess the effect of electromagnetic field (EMF) from the GSM mobile phone system on human brain function. The assessment was based on the assay of event related potentials (ERPs). MATERIAL AND METHODS: The study group consisted of 15 volunteers, including 7 men and 8 women. The test protocol comprised determination of P300 wave in each volunteer during exposure to the EMF. To eliminate possible effects of the applied test procedure on the final result, the test was repeated without EMF exposure. P300 latency, amplitude, and latency of the N1, N2, P2 waves were analysed. RESULTS: The statistical analysis revealed an effect of EMF on P300 amplitude. In the experiment with EMF exposure, lower P300 amplitudes were observed only at the time in which the volunteers were exposed to EMF; when the exposure was discontinued, the values of the amplitude were the same as those observed before EMF application. No such change was observed when the experiment was repeated with sham exposure, which may be considered as an indirect proof that lower P300 amplitude values were due to EMF exposure. No statistically significant changes were noted in the latencies of the N1, N2, P2 waves that precede the P300 wave, nor in the latency of the P300 itself. CONCLUSIONS: The results suggest that exposure to GSM EMF exerts some effects on CNS, including effects on long latency ERPs.
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Telefone Celular , Campos Eletromagnéticos/efeitos adversos , Potenciais Evocados P300/efeitos da radiação , Feminino , Humanos , MasculinoRESUMO
BACKGROUND: Occupational hearing loss and its diagnostic methods are one of the subjects of great interest in the field of occupational medicine and hygiene. The primary aim of the work was to determine the characteristics of ready-made filters used to process the brainstem auditory evoked potentials. No data on the properties of these filters have prompted the author to verify the algorithm of their operations with particular reference to their effects on the results and their interpretation. MATERIAL AND METHODS: A Nicolet model Spirit 2000 Unit and a phantom of the author's own design were used in the experiment. The phantom simulated the patient's skin resistance and brainstem responses to the presented auditory stimulus. The filter characteristics was verified in two stages. First, the signals generated by electromagnetic induction between the measuring leads and earphone coils were employed. Second, a precise source of the composite signal simulating the brainstem response was used. The study protocol comprised a series of tests using ready-made filters: a neuronal, a linear, and an arithmetical averaging filter. RESULTS: The arithmetical averaging resulted in the most real representation of the reference signal, the use of the linear filter resulted in the phase shift of the high-amplitude reference signal, while the use of the neuronal filter resulted in the phase shift of the low-amplitude reference signal. CONCLUSION: The use of filters may lead to the distortion of the input signal. When analysing the results of evoked potential determinations with use of filters, the type of the filter and its effects on the input signal must be taken into account.
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Potenciais Evocados Auditivos do Tronco Encefálico , Modelos Biológicos , Processamento de Sinais Assistido por Computador , Algoritmos , Artefatos , Impedância Elétrica , Filtração , Humanos , Modelos Neurológicos , Pele/metabolismoRESUMO
In the opinion of some experts, a growing emission of man-made electromagnetic fields (EMF), also known as electromagnetic is a source of continuously increasing health hazards to the general population. Due to their large number and very close proximity to the user's head, mobile phones deserve special attention. This work is intended to give a systematic review of objective studies, assessing the effects of mobile phone EMF on the functions of the central nervous system (CNS) structures. Our review shows that short exposures to mobile phone EMF, experienced by telephone users during receiving calls, do not affect the cochlear function. Effects of GSM mobile phone EMF on the conduction of neural impulses from the inner car neurons to the brainstem auditory centres have not been detected either. If Picton's principle, saying that P300 amplitude varies with the improbability of the targets and its latency varies with difficulty of discriminating the target stimulus from standard stimuli, is true, EMF changes the improbability of the targets without hindering their discrimination. Experiments with use of indirect methods do not enable unequivocal verification of EMF effects on the cognitive functions due to the CNS anatomical and functional complexity. Thus, it seems advisable to develop a model of EMF effects on the excitable brain structures at the cellular level.
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Telefone Celular , Sistema Nervoso Central/efeitos da radiação , Campos Eletromagnéticos/efeitos adversos , Exposição Ambiental/efeitos adversos , Potenciais Evocados Auditivos do Tronco Encefálico/efeitos da radiação , Doses de Radiação , Feminino , Humanos , Masculino , Fatores de RiscoRESUMO
OBJECTIVES: Intoxication with novel psychoactive drugs poses a significant challenge for medicine due to diagnostic difficulties, complex clinical patterns resulting from the polyethiology of poisoning, and the risk of fatal complications. MATERIAL AND METHODS: The authors of the present work have made a retrospective review of medical records of the patients hospitalized at the Toxicology Unit (TU), diagnosed with poisoning by novel recreational drugs. RESULTS: In 2008-2013, 576 patients diagnosed with that type of poisoning were admitted to the TU. Of those, 192 (33.3%) patients were positive for ethanol in addition to the most popular toxins found in the material collected from the patients, such as tetrahydrocannabinol (50 [8.6%] patients) and amphetamine (35 [6.1%] patients). The most frequent clinical symptoms observed on admission were: anxiety (433 [75.1%] patients), agitation (275 [47.7%] patients), and complaints associated with the circulatory system (225 [39.1%] patients). In the subgroup of 104 (18.0%) psychiatrist-interviewed people, a relationship was found between the suicidal ideation reported during history-taking and the following factors: earlier psychiatric treatment (p = 0.000), financial problems (p = 0.015) and prolonged unemployment (p = 0.022). CONCLUSIONS: The observed clinical pattern may be associated with sympathomimetic syndrome due to poisoning by novel psychoactive substances. Preliminary results of this research show that financial problems and a history of psychiatric treatment may enhance suicidal ideation in patients after acute poisoning by psychoactive substances. Int J Occup Med Environ Health. 2020;33(4):445-55.
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Overdose de Drogas/epidemiologia , Drogas Ilícitas/intoxicação , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Adolescente , Adulto , Overdose de Drogas/diagnóstico , Etanol/intoxicação , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Polônia/epidemiologia , Estudos Retrospectivos , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Transtornos Relacionados ao Uso de Substâncias/psicologia , Ideação Suicida , DesempregoRESUMO
Poland's access to the EU causes that there is the risk of poisoning from sources outside Poland. This is confirmed by the case reported below. The Weeverfish Trachinus draco lives in the coastal waters of West Africa and Europe (including those of the Mediterranean Sea) and belongs to the most poisonous fish species. The venom of Trachinus draco contains proteins that cause cellular membrane depolarisation, and haemolysis. A 35-yr. man was admitted to the Toxicological Department of the Nofer Institute of Occupational Medicine for symptoms, such as: a strong pain, swelling and reddening of the left leg, that had appeared after contact with an unidentified fish when he had been enjoying a bath in the Mediterranean Sea. In the additional examinations, slight abnormalities were detected only in the results of blood agglutination test. The patient was discharged from the hospital 7 days later in good condition.
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Mordeduras e Picadas/diagnóstico , Venenos de Peixe/intoxicação , Natação/lesões , Adulto , Mordeduras e Picadas/complicações , Edema/etiologia , Humanos , Masculino , Mar Mediterrâneo , Dor/etiologiaRESUMO
The purpose of this study was to analyze the white blood cell (WBC) percentage pattern of patients with myeloperoxidase disorder. During the 18 months of routine work, 36 blood samples were found with disorders of myeloperoxidase activity: 12 cases of total myeloperoxidase (MPOt) deficiency and 24 cases of partial myeloperoxidase (MPOp) deficiency. In the group with MPOp, according to the results, monocytes (MONO) were the dominant population 33.2%±21.3; however, the microscopic evaluation of leucocytes showed the dominance of neutrophil (NEUT). The average NEUT value was 66.63%±12.31; LYMPH 23.33%±10.08; MONO 6.00%±3.20; EOS 2.04%±2.20; BASO 0.29%±0.62; ATYP 0.83%±1.09. In the group with MPOt, the results of automated leukocyte analysis showed that the dominant group consisted of large unstained cells (LUC) 72.6%±8.64. LUC category reflects large immature cells such as blusts. In the microscopic evaluation: NEUT 67% ±11.40; LYMPH 23%±8.94; MONO 6.17%±3.47; EOS 1.25%±1.06; BASO 0.08%±0.29; ATYP 0.92%±1.38. During microscopic verification, no LUC cells were found. Results of the evaluation of automatic WBC separation according to morphology and functionality of cells led to the conclusion that monocyte dominance in the differential WBC count is associated with a high likelihood of MPOp, and the domination of large unstained cells with MPOt.
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Biomarcadores/análise , Separação Celular/métodos , Leucócitos/patologia , Erros Inatos do Metabolismo/diagnóstico , Monócitos/patologia , Neutrófilos/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Adulto JovemRESUMO
Questionnaire and audiometric data of 701 dockyard workers (517 noise and organic solvent mixture-exposed and 184 noise-only-exposed) were referred to 205 control subjects not exposed to either noise or solvents. The odds ratio (OR) of hearing loss was significantly increased by approximately 3 times in the noise-only group and by almost 5 times in the noise and solvent group. A moderate effect of solvent ototoxicity, in addition to noise, was observed on hearing threshold at a frequency 8 kHz. ORs for hearing loss were 1.12 for each increment of 1 year of age, 1.07 for every decibel of lifetime noise exposure (dB-A), and 1.004 for each increment of the index of lifetime exposure to solvents. The results suggest an additive damaging effect of coexposure to noise and organic solvents to the auditory organ.
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Perda Auditiva/etiologia , Ruído Ocupacional/efeitos adversos , Exposição Ocupacional/efeitos adversos , Solventes/efeitos adversos , Adulto , Feminino , Perda Auditiva/induzido quimicamente , Perda Auditiva/epidemiologia , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Risco , Inquéritos e QuestionáriosRESUMO
OBJECTIVES: A widespread use of mobile phones evokes a growing concern for their possible adverse effects on the human central nervous system. This study was aimed at evaluating the effects of EMF generated by mobile phones, at all standard wavelengths: 450, 935 and 1800 MHz used in Poland, on the auditory brainstem-evoked responses (ABR) during and after the exposure. MATERIALS AND METHODS: The effects of acute exposure to electromagnetic fields (EMF) on ABR were evaluated in 45 young, healthy volunteers of both genders. The electromagnetic impulses were generated with the antenna of mobile phone. The exposure was induced by repeated phone activation for 20 min. The ABR evaluation was performed before, during and immediately after the exposure, and the latencies of waves I, III and V, and inter-waves I-V were analyzed. RESULTS: Prior test calibration on a phantom did not show the influence of the external EMF generated by the mobile phone on the ABR equipment. For neither EMF frequency, differences were observed in wave and inter-wave latencies during and after exposure to EMF compared to the initial ABR pattern, in both men and woman. CONCLUSIONS: This implies that commonly used mobile phones do not affect propagation of electrical stimuli along the auditory nerve to auditory brainstem centers.
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Telefone Celular , Campos Eletromagnéticos/efeitos adversos , Potenciais Evocados Auditivos do Tronco Encefálico/efeitos da radiação , Adulto , Análise de Variância , Feminino , Humanos , MasculinoRESUMO
OBJECTIVES: Firearm is a common source of impulse noise that may potentially damage hearing organ. It has been suggested that otoacoustic emissions, particularly transient-evoked otoacoustic emissions (TEOAE), might be more sensitive than pure-tone audiometry (PTA) in the assessment of changes to cochlea caused by noise. The aim of this study was to: (i) evaluate exposure to impulse noise from small-caliber weapons, (ii) compare the post-exposure changes in hearing measured by PTA and TEOAE and correlate them with noise parameters. MATERIALS AND METHODS: The study included 18 male hunters (group I) and 28 candidate policemen (group II) exposed to impulse noise from small firearms during target practices. Group I was unprotected during shooting, whereas group II used commonly available hearing protectors. PTA and TEOAE were performed before and 2-10 min after shooting. Exposure to impulse noise was evaluated by in situ measurements. RESULTS: Groups I and II were exposed to 3-4 and 4-144 impulses of noise at mean C-weighted peak sound pressure levels of 154 dB and 156 dB, respectively. No post-exposure audiometric threshold shift was observed in group I. Significant reductions of TEOAE levels were found both for the whole response (-2.2 dB SPL) and for 1/2 -octave band responses in the frequency range of 1000-4000 Hz (from -1.6 to -3.0 dB SPL). These changes were not correlated with C-weighted peak sound pressure levels or equivalent-continuous A-weighted sound pressure level. Significant correlation was found for peak sound pressure and maximum sound pressure levels in 1/3-octave bands in the frequency range corresponding with the main part of the acoustic energy of impulses (correlation coefficients r from -0.58 to -0.77, p < 0.05). In group II neither PTA nor TEOAE showed significant hearing impairment after shooting. CONCLUSIONS: The results show that even short-term exposure to impulse noise from small-calibre firearms might cause temporary hearing impairment measured by TEOAE. Therefore, the use of earmuffs is strongly recommended, because most of them seem to effectively attenuate impulse noise from small-calibre firearms.