Josilene Luciene Duarte

Potencial cognitivo P300 em indivíduos com diabetes mellitus

Diabetes Mellitus pode acarretar complicacoes nos olhos, rins, nervos cranianos, nervos perifericos, ouvidos, etc. A funcao cognitiva tambem parece estar prejudicada em individuos portadores de Diabetes Mellitus, visto que as estruturas corticais e subcorticais responsaveis por esta funcao estao prejudicadas em alguns pacientes dependentes de insulina. O potencial cognitivo P300 tem sido usado como um procedimento objetivo para avaliar a funcao cognitiva cerebral. OBJETIVO: Analisar a sensibilidade do potencial cognitivo P300 para detectar alteracoes no cortex auditivo decorrentes do Diabetes Mellitus. FORMA DE ESTUDO: coorte transversal. MATERIAL E METODO: Participaram deste estudo 16 individuos diabeticos de ambos os sexos, com idade variando de 7 a 71 anos, e 17 individuos nao-diabeticos equiparados quanto ao sexo, idade e limiar auditivo. Os procedimentos de avaliacao foram: Audiometria Tonal Liminar (ATL) e potencial cognitivo P300. No grupo diabetico foi realizada a medida do valor glicemico antes da realizacao do P300. RESULTADOS: Os resultados obtidos na ATL nao mostraram diferenca estatisticamente significante. Foi observado diferenca estatisticamente significante entre os grupos, quando analisado a latencia do componente P3, medido em Fz. Houve correlacao entre a glicemia e a latencia e amplitude do P300. CONCLUSAO: A pesquisa do potencial cognitivo P300 e um importante procedimento para prevenir e diagnosticar precocemente de alteracoes neurologicas em individuos com Diabetes Mellitus.

Potencial evocado auditivo de longa latência-P300 em indivíduos normais: valor do registro simultâneo em Fz e Cz

The P300 is and auditory Evoked Potential, called endogenous potential because it reflects the functional use the individual makes of the auditory stimulus, being highly dependent on cognitive skills; among them we list attention and auditory discrimination. It is a procedure of objective evaluation; however, one that depends on the examiners experience to detect wave peaks, and it is important to use recording methods that facilitate the response presence analysis and result interpretation. AIM: to analyze the P300 Long Latency Auditory Evoked Potential obtained through the use of two active electrodes positioned on Fz and Cz. MATERIALS AND METHODS: 330 individuals from both genders and age ranging between 7 and 34 years participated in this study, they all had normal hearing and did not have any risk factor for mental problems. RESULTS: Results show that there was no statistically significant difference for N2 and P3 latency and P3 amplitude as far as gender is concerned, nor correlation with the individuals age. There was a strong correlation of these measures with Fz and Cz electrode positioning. CONCLUSION: Fz and Cz active electrodes positioning can be considered one more resource to help in the P300 clinical analysis.

Effects of passive smoke inhalation on the vocal cords of rats

UNLABELLED Few studies have demonstrated the pathologic reactions yielded by smoke inhalation on the airway in rats. AIM The aim of this study was to analyze the possible histopathological effects produced by chronic cigarette smoke inhalation on the vocal folds of rats. STUDY DESIGN Experimental. MATERIAL AND METHOD 36 male rats (Rattus norvergicus Wistar strain), aged 60 days, were kept in cages and exposed to inhalation of the smoke produced by 10 cigarettes lit 3 times a day, 7 days a week, for periods of 25, 50 and 75 days, and their respective controls. Thereafter the animals were killed and their larynxes were dissected and submitted to histological processing for achievement of histological sections, which were stained with Hematoxylin and Eosin and analyzed by light microscopy. RESULTS The rats exposed to smoke displayed smaller (p< 0,05) body mass than the control group. There was hyperplasia and squamous metaplasia in the free edge of the vocal fold and squamous hyperplasia on the middle portion of the vocal fold in all 3 study periods. Moreover, the 50-day group revealed keratinizing metaplasia in this area. Morphological alterations in other areas of the larynx and inflammatory reaction of the lamina propria were also not observed. CONCLUSION It was concluded that the passive inhalation of cigarette smoke yields important morphological changes in the vocal fold epithelium, which may progress to neoplasia.

Efeitos da inalação passiva da fumaça de cigarro sobre as pregas vocais de ratos

Few studies have demonstrated the pathologic reactions yielded by smoke inhalation on the airway in rats. AIM: The aim of this study was to analyze the possible histopathological effects produced by chronic cigarette smoke inhalation on the vocal folds of rats. STUDY DESIGN: Experimental. MATERIAL AND METHOD: 36 male rats (Rattus norvergicus Wistar strain), aged 60 days, were kept in cages and exposed to inhalation of the smoke produced by 10 cigarettes lit 3 times a day, 7 days a week, for periods of 25, 50 and 75 days, and their respective controls. Thereafter the animals were killed and their larynxes were dissected and submitted to histological processing for achievement of histological sections, which were stained with Hematoxylin and Eosin and analyzed by light microscopy. RESULTS: The rats exposed to smoke displayed smaller (p< 0,05) body mass than the control group. There was hyperplasia and squamous metaplasia in the free edge of the vocal fold and squamous hyperplasia on the middle portion of the vocal fold in all 3 study periods. Moreover, the 50-day group revealed keratinizing metaplasia in this area. Morphological alterations in other areas of the larynx and inflammatory reaction of the lamina propria were also not observed. CONCLUSION: It was concluded that the passive inhalation of cigarette smoke yields important morphological changes in the vocal fold epithelium, which may progress to neoplasia.

A resposta auditiva de estado estável na avaliação auditiva: aplicação clínica

TEMA: a resposta auditiva de estado estavel (RAEE) e um procedimento eletrofisiologico que permite avaliar ao mesmo tempo os limiares auditivos de varias frequencias em ambas as orelhas, reduzindo assim o tempo de teste, e permite estimular ate niveis proximos a 125dB HL, caracterizando assim a audicao residual. OBJETIVO: verificar a aplicabilidade da RAEE para determinar os limiares auditivos nos diferentes graus de perda auditiva neurossensorial coclear. METODO: foram avaliados 48 individuos com idade entre sete e trinta anos e diferentes graus de perdas auditivas. A Audiometria Tonal Liminar (ATL) e a RAEE foram avaliadas nas seguintes frequencias portadoras, 0,5; 1; 2 e 4k Hz. As frequencias portadoras na RAEE foram moduladas em amplitude e frequencia, com estimulacao multipla e dicotica nas perdas auditivas de grau leve e moderado. Estimulacao simples foi utilizada nos outros graus de perdas auditivas. RESULTADOS: houve associacao significante (p < 0,01) entre os limiares obtidos na ATL e RAEE para todas as frequencias testadas, principalmente para perdas auditivas de grau profundo. Contudo em alguns pacientes o grau da perda auditiva pode ser super-estimado. CONCLUSAO: a RAEE pode ser utilizada para predizer os limiares auditivos da ATL, porem nao deve ser analisada de forma isolada, mas de forma complementar a avaliacao audiologica comportamental.BACKGROUND the auditory steady state response (ASSR) is an electrophysiological procedure that evaluates, at the same time, the hearing thresholds of both ears at various frequencies. This procedure reduces the time of testing and enables the stimulation of levels close to 125dB HL, characterizing residual hearing. AIM to verify the applicability of the ASSR to determine the hearing thresholds in different levels of sensorineural hearing loss. METHOD 48 individuals aged 7-30 years, with different levels of hearing loss were assessed. The Pure tone Audiometry (PTA) and the ASSR were carried out in following carrier frequencies 0.5; 1; 2 and 4k Hz. The carrier frequencies in the ASSR were modulated in amplitude and frequency, with multiple dicotic stimulation for mild and moderate hearing loss. Simple stimulation was used to test the other hearing deficit levels. RESULTS there was a significant association (p<0.01) between the thresholds obtained in the PTA and in the ASSR for all of the tested frequencies, especially for the severe levels. However, for some patients, the hearing loss level was overestimated in the ASSR. CONCLUSION the ASSR can be used to estimate the PTA threshold; nevertheless, it should not be analyzed in an isolated way, but seen as a complementary procedure to the behavioral auditory assessment.

Potencial cognitivo P300 realizado em campo livre: aplicabilidade do teste

Avaliar a funcao auditiva em usuarios de dispositivos eletronicos aplicados a surdez e muito importante para o processo de reabilitacao. Entretanto, nestes individuos os procedimentos devem ser realizados em campo livre. OBJETIVO: Analisar a aplicabilidade do potencial cognitivo P300 pesquisado em campo livre. FORMA DE ESTUDO: Clinico prospectivo. MATERIAL E METODO: Foram avaliados 33 individuos de ambos os sexos com idade entre 7 e 34 anos, com audicao normal e sem fator de risco para problemas mentais. O potencial cognitivo P300 foi realizado por meio do equipamento Biologics Evoked Potential System (EP), com fones de insercao (3A) e em campo livre (0o Azimute e 45o Azimute). RESULTADOS: Nao houve diferenca estatisticamente significante para a latencia do N2 e P300 e amplitude do P300 quando analisado o sexo e o modo de realizacao do teste (fone e campo livre), assim como nao houve diferenca ao comparar as medidas em campo livre a 0o e 45o Azimute. CONCLUSAO: A pesquisa do potencial cognitivo P300 em campo livre e um procedimento viavel de ser realizado.

P300-long-latency auditory evoked potential in normal hearing subjects: simultaneous recording value in Fz and Cz

UNLABELLED The P300 is and auditory Evoked Potential, called endogenous potential because it reflects the functional use the individual makes of the auditory stimulus, being highly dependent on cognitive skills; among them we list attention and auditory discrimination. It is a procedure of objective evaluation; however, one that depends on the examiners experience to detect wave peaks, and it is important to use recording methods that facilitate the response presence analysis and result interpretation. AIM To analyze the P300 Long Latency Auditory Evoked Potential obtained through the use of two active electrodes positioned on Fz and Cz. MATERIALS AND METHODS 330 individuals from both genders and age ranging between 7 and 34 years participated in this study, they all had normal hearing and did not have any risk factor for mental problems. RESULTS Results show that there was no statistically significant difference for N2 and P3 latency and P3 amplitude as far as gender is concerned, nor correlation with the individuals age. There was a strong correlation of these measures with Fz and Cz electrode positioning. CONCLUSION Fz and Cz active electrodes positioning can be considered one more resource to help in the P300 clinical analysis.

Cognitive P300 potential in subjects with diabetes mellitus

UNLABELLED Diabetes Mellitus may lead to alterations in the eyes, kidneys, cranial nerves, peripheral nerves, ears etc. The cognitive function also seems to be compromised in subjects presented with Diabetes Mellitus, since the cortical and subcortical structures responsible for this function are hindered in some insulin-dependent patients. The cognitive potential P300 has been used as an objective procedure to assess cerebral cognitive functions. AIM To analyze the sensitivity of P300 cognitive potential for the detection of alterations on the auditory cortex secondary to Diabetes Mellitus. STUDY DESIGN transversal cohort. MATERIAL AND METHOD Sixteen diabetic subjects of both genders aged 7 to 71 years, and seventeen non-diabetic individuals at the same age range participated in this study. The evaluation procedures were pure tone audiometry (PTA) and P300 cognitive potential. Glycemia of the group presented with Diabetes was assessed prior to applying P300. RESULTS No statistically significant difference was shown for PTA results. A statically significant difference was observed between groups when analyzing the latency of P300 component measured in Fz. There was a correlation between glycemia and latency and amplitude of P300. CONCLUSION The investigation of the cognitive potential of P300 is an important procedure for prevention and early diagnosis of neurological changes in individuals presented with Diabetes Mellitus.

Influence of iron on modulation of the antioxidant system in rat brains exposed to lead.

The objective of this study was to evaluate markers of oxidative stress in the brains of rats exposed to lead acetate (Pb(C2H3O2)2), either associated or not associated with ferrous sulfate (FeSO4). A total of 36 weaning rats (Rattus norvegicus) were divided into 6 groups of six animals and exposed to lead acetate for six weeks. In the control group (control), the animals received deionized water. The Pb260 and Pb260 + Fe received 260 µM lead acetate, and the Pb1050 and Pb1050 + Fe received 1050 µM lead acetate. The Pb260 + Fe and Pb1050 + Fe were supplemented with 20 mg of ferrous sulfate/Kg body weight every 2 days. Group Fe received deionized water and ferrous sulfate. The rat brains were collected to analyze the enzymatic activity of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and the concentration of reduced glutathione (GSH), lipid peroxidation (TBARS), and total antioxidant substance (TAS) (DPPH• technique). The activity of SOD and GPx in the experimental groups decreased compared to the control, together with the concentration of GSH (p < 0.05). For CAT analysis, SOD tended to increase in concentration in the experimental groups without a concomitant exposure to FeSO4, whereas GPx showed a slight tendency to increase in activity compared to the control. For TAS‐DPPH•, there was a decrease in the experimental groups (p < 0.05). According to the results, SOD, GPx, and GSH were affected by lead acetate and exposure to ferrous sulfate changed this dynamic. However, further studies are needed to verify whether ferrous sulfate acts as a protectant against the toxic effects of lead.

Correlation analysis of the long latency auditory evoked potential N2 and cognitive P3 with the level of lead poisoning in children

Summary Introduction: The effects of lead on childrens health have been widely studied. Aim: To analyze the correlation between the long latency auditory evoked potential N2 and cognitive P3 with the level of lead poisoning in Brazilian children. Methods: This retrospective study evaluated 20 children ranging in age from 7 to 14 years at the time of audiological and electrophysiological evaluations. We performed periodic surveys of the lead concentration in the blood and basic audiological evaluations. Furthermore, we studied the auditory evoked potential long latency N2 and cognitive P3 by analyzing the absolute latency of the N2 and P3 potentials and the P3 amplitude recorded at Cz. At the time of audiological and electrophysiological evaluations, the average concentration of lead in the blood was less than 10 ug/dL. Results: In conventional audiologic evaluations, all children had hearing thresholds below 20 dBHL for the frequencies tested and normal tympanometry findings; the auditory evoked potential long latency N2 and cognitive P3 were present in 95% of children. No significant correlations were found between the blood lead concentration and latency (p = 0.821) or amplitude (p = 0.411) of the P3 potential. However, the latency of the N2 potential increased with the concentration of lead in the blood, with a significant correlation (p = 0.030). Conclusion: Among Brazilian children with low lead exposure, a significant correlation was found between blood lead levels and the average latency of the auditory evoked potential long latency N2; however, a significant correlation was not observed for the amplitude and latency of the cognitive potential P3.