Effect of genetic polymorphisms rs2301113 and rs2057482 in the expression of HIF-1α protein in periodontal ligament fibroblasts subjected to compressive force.

OBJECTIVE: Many genes and signaling molecules are involved in orthodontic tooth movement, with mechanically and hypoxically stabilized HIF-1α having been shown to play a decisive role in periodontal ligament signaling during orthodontic tooth movement. Thus, this in vitro study aimed to investigate if genetic polymorphisms in HIF1A (Hypoxia-inducible factor α-subunits) influence the expression pattern of HIF-1α protein during simulated orthodontic compressive pressure. METHODOLOGY: Samples from human periodontal ligament fibroblasts were used and their DNA was genotyped using real time Polymerase chain reaction for the genetic polymorphisms rs2301113 and rs2057482 in HIF1A . For cell culture and protein expression experiments, six human periodontal ligament fibroblast cell lines were selected based on the patients' genotype. To simulate orthodontic compressive pressure in fibroblasts, a 2 g/cm2 force was applied under cell culture conditions for 48 hours. Protein expression was evaluated by Western Blot. Paired t-tests were used to compare HIF-1α expression with and without compressive pressure application and unpaired t-tests were used to compare expression between the genotypes in rs2057482 and rs2301113 (p<0.05). RESULTS: The expression of HIF-1α protein was significantly enhanced by compressive pressure application regardless of the genotype (p<0.0001). The genotypes in the genetic polymorphisms rs2301113 and rs2057482 were not associated with HIF-1α protein expression (p>0.05). CONCLUSIONS: Our study confirms that compressive pressure application enhances HIF-1α protein expression. We could not prove that the genetic polymorphisms in HIF1A affect HIF-1α protein expression by periodontal ligament fibroblasts during simulated orthodontic compressive force.

Single Nucleotides Polymorphisms in COX2 Gene and their Association with Signs and Symptoms of Teething - A Pilot Study

ABSTRACT Objective: To investigate the association between single nucleotide polymorphisms in the COX2 gene (rs689466 and rs5275) and local and systemic signs and symptoms of teething. Material and Methods: Forty-four pairs of mothers-babies/toddlers were included. Erupted primary teeth were evaluated during clinical examination. Local and systemic signs and symptoms of teething were obtained from mothers' reporting via anamnesis. Samples of buccal cells were retrieved for DNA genotyping using real-time PCR. The T-test, Chi-square test, logistic regression, and haplotype analyses were applied. Results: Almost all mothers (95.5%) reported at least one local or systemic sign and symptom of teething. The most common was increased salivation (79.5%), diarrhea (72.3 %), and fever (70.5 %). The mean number of signs and symptoms per child was higher in boys than girls (mean = 5.1; SD= 1.5; p=0.008). Sleep disturbance (p=0.03) and loss of appetite (p=0.05) were more reported in boys. The rs689466 and rs5275 were not associated with signs and symptoms of teething (p>0.05). Conclusion: The single nucleotide polymorphisms in the COX2 gene (rs689466 and rs5275) were not associated with local and systemic signs and symptoms of teething.

Effect of genetic polymorphisms rs2301113 and rs2057482 in the expression of HIF-1α protein in periodontal ligament fibroblasts subjected to compressive force

Abstract Objective Many genes and signaling molecules are involved in orthodontic tooth movement, with mechanically and hypoxically stabilized HIF-1α having been shown to play a decisive role in periodontal ligament signaling during orthodontic tooth movement. Thus, this in vitro study aimed to investigate if genetic polymorphisms in HIF1A (Hypoxia-inducible factor α-subunits) influence the expression pattern of HIF-1α protein during simulated orthodontic compressive pressure. Methodology Samples from human periodontal ligament fibroblasts were used and their DNA was genotyped using real time Polymerase chain reaction for the genetic polymorphisms rs2301113 and rs2057482 in HIF1A . For cell culture and protein expression experiments, six human periodontal ligament fibroblast cell lines were selected based on the patients' genotype. To simulate orthodontic compressive pressure in fibroblasts, a 2 g/cm2 force was applied under cell culture conditions for 48 hours. Protein expression was evaluated by Western Blot. Paired t-tests were used to compare HIF-1α expression with and without compressive pressure application and unpaired t-tests were used to compare expression between the genotypes in rs2057482 and rs2301113 (p<0.05). Results The expression of HIF-1α protein was significantly enhanced by compressive pressure application regardless of the genotype (p<0.0001). The genotypes in the genetic polymorphisms rs2301113 and rs2057482 were not associated with HIF-1α protein expression (p>0.05). Conclusions Our study confirms that compressive pressure application enhances HIF-1α protein expression. We could not prove that the genetic polymorphisms in HIF1A affect HIF-1α protein expression by periodontal ligament fibroblasts during simulated orthodontic compressive force.

The effect of adenotonsillectomy and rapid maxillary expansion on the upper airway in pediatric obstructive sleep apnea: a randomized crossover-controlled trial.

STUDY OBJECTIVES: We aimed to determine the effects of adenotonsillectomy (AT) and rapid maxillary expansion (RME) on the apnea-hypopnea index (AHI) and compare volumetric changes in the upper airway (UA) arising from AT and RME. METHODS: Thirty-nine children who presented with maxillary constriction and grade III/IV tonsillar hypertrophy were randomized into two groups. One group underwent AT as the first treatment, and the other group underwent RME. Polysomnography (PSG) and cone-beam computed tomography (CBCT) were conducted before (T0) and 6 months after the first treatment (T1). In a crossover design, individuals with AHI>1 received the second treatment. Six months later, they underwent PSG and CBCT (T2). The influence of age, sex, tonsil and adenoid hypertrophy, initial AHI severity, initial volume of the UA, first treatment, and maxillary expansion amount was evaluated using linear regression analysis. Intra- and inter-group comparisons for AHI and inter-group comparisons of volumetric changes in each region of the UA were performed using a paired t-test and Wilcoxon test. RESULTS: The initial AHI severity and therapeutic sequence in which AT was the first treatment explained for 95.6% of AHI improvement. AT caused significant improvements in the AHI and volumetric increases in the buccopharynx and total UA areas compared to RME. CONCLUSIONS: The initial AHI severity and AT as the first treatment accounted for most of the AHI improvement. Most reductions in AHI were due to AT, which promoted more volumetric increases in UA areas than RME. RME may have a marginal effect on pediatric obstructive sleep apnea.

The role of 25-hydroxyvitamin-D3 and vitamin D receptor gene in human periodontal ligament fibroblasts as response to orthodontic compressive strain: an in vitro study.

BACKGROUND: This study aimed to investigate, if different physiological concentrations of vitamin D (25(OH)D3) and single nucleotide polymorphisms in vitamin D receptor (VDR) gene have an impact on gene expression in human periodontal ligament (hPDL) fibroblasts induced by simulated orthodontic compressive strain. METHODS: A pool of hPDL fibroblasts was treated in absence or presence of 25(OH)D3 in 3 different concentrations (10, 40 and 60 ng/ml). In order to evaluate the role of single nucleotide polymorphisms in the VDR gene, hPDL fibroblasts from 9 patients were used and treated in absence or presence of 40 ng/ml 25(OH)D3. Each experiment was performed with and without simulated orthodontic compressive strain. Real-time PCR was used for gene expression and allelic discrimination analysis. Relative expression of dehydrocholesterol reductase (DHCR7), Sec23 homolog A, amidohydrolase domain containing 1 (AMDHD1), vitamin D 25-hydroxylase (CYP2R1), Hydroxyvitamin D-1-α hydroxylase, receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG), cyclooxygenase-2 (COX-2) and interleukin-6 (IL6) was assessed. Three single nucleotide polymorphisms in VDR were genotyped. Parametric or non-parametric tests were used with an alpha of 5%. RESULTS: RANKL, RANKL:OPG ratio, COX-2, IL-6, DHCR7, CYP2R1 and AMDHD1 were differentially expressed during simulated orthodontic compressive strain (p < 0.05). The RANKL:OPG ratio was downregulated by all concentrations (10 ng/ml, 40 ng/ml and 60 ng/ml) of 25(OH)D3 (mean = 0.96 ± 0.68, mean = 1.61 ± 0.66 and mean = 1.86 ± 0.78, respectively) in comparison to the control (mean 2.58 ± 1.16) (p < 0.05). CYP2R1 gene expression was statistically modulated by the different 25(OH)D3 concentrations applied (p = 0.008). Samples from individuals carrying the GG genotype in rs739837 presented lower VDR mRNA expression and samples from individuals carrying the CC genotype in rs7975232 presented higher VDR mRNA expression (p < 0.05). CONCLUSIONS: Simulated orthodontic compressive strain and physiological concentrations of 25(OH)D3 seem to regulate the expression of orthodontic tooth movement and vitamin-D-related genes in periodontal ligament fibroblasts in the context of orthodontic compressive strain. Our study also suggests that single nucleotide polymorphisms in the VDR gene regulate VDR expression in periodontal ligament fibroblasts in the context of orthodontic compressive strain.

Estrogen deficiency affects tooth formation and gene expression in the odontogenic region of female rats.

BACKGROUND: There is some evidence that estrogen regulates the expression of several genes in different cells, including dental cells. Therefore, the aim of this study was to investigate the role of estrogen deficiency during tooth development regarding tooth structure morphology and its impact on the expression of odontogenesis-related genes. METHODS: A total of 40 female Wistar rats was divided into OVX (estrogen deficiency) and Sham (control) groups. Bilateral ovariectomy was performed in the OVX group, while Sham surgery was performed in the control group at the age of 21 days. At an age of 56 days, 16 rats were euthanized for gene expression analyses of Bmp4, Smad6, Tgfb1 and Runx2. At the age of 63 days, the remaining rats were euthanized for histological and morphometric analyses of teeth. The mandibles of the rats were submitted to µCT analysis. Tooth structures (enamel, dentin and dental pulp) were analyzed. T test was used to compare the mean differences between groups (p<0.05). RESULTS: In the µCT analysis, enamel and dentin thickness were significantly increased in the control group (p<0.0001). Pulp dimensions were significantly larger in the OVX group (p<0.0001). A reduction of tooth structures in the OVX group was confirmed in HE staining. Smad6 was differentially expressed in the OVX group (p=0.04). CONCLUSION: Estrogen deficiency affects gene expression in the odontogenic region and tooth structure morphology.

Rational Design of W-Doped Ag3PO4 as an Efficient Antibacterial Agent and Photocatalyst for Organic Pollutant Degradation.

Bacterial and organic pollutants are major problems with potential adverse impacts on human health and the environment. A promising strategy to alleviate these impacts consists in designing innovative photocatalysts with a wider spectrum of application. In this paper, we report the improved photocatalytic and antibacterial activities of chemically precipitated Ag3PO4 microcrystals by the incorporation of W at doping levels 0.5, 1, and 2 mol %. The presence of W directly influences the crystallization of Ag3PO4, affecting the morphology, particle size, and surface area of the microcrystals. Also, the characterization via experimental and theoretical approaches evidenced a high density of disordered [AgO4], [PO4], and [WO4] structural clusters due to the substitution of P5+ by W6+ into the Ag3PO4 lattice. This leads to new defect-related energy states, which decreases the band gap energy of the materials (from 2.27 to 2.04 eV) and delays the recombination of e'-h• pairs, leading to an enhanced degradation process. As a result of such behaviors, W-doped Ag3PO4 (Ag3PO4:W) is a better visible-light photocatalyst than Ag3PO4, demonstrated here by the photodegradation of potential environmental pollutants. The degradation of rhodamine B dye was 100% in 4 min for Ag3PO4:W 1%, and for Ag3PO4, the obtained result was 90% of degradation in 15 min of reaction. Ag3PO4:W 1% allowed the total degradation of cephalexin antibiotic in only 4 min, whereas pure Ag3PO4 took 20 min to achieve the same result. For the degradation of imidacloprid insecticide, Ag3PO4:W 1% allowed 90% of degradation, whereas Ag3PO4 allowed 40%, both in 20 min of reaction. Moreover, the presence of W-dopant results in a 16-fold improvement of bactericidal performance against methicillin-resistant Staphylococcus aureus. The outstanding results using the Ag3PO4:W material demonstrated its potential multifunctionality for the control of organic pollutants and bacteria in environmental applications.

Microwave-Driven Hexagonal-to-Monoclinic Transition in BiPO4: An In-Depth Experimental Investigation and First-Principles Study.

Present theoretical and experimental work provides an in-depth understanding of the morphological, structural, electronic, and optical properties of hexagonal and monoclinic polymorphs of bismuth phosphate (BiPO4). Herein, we demonstrate how microwave irradiation induces the transformation of a hexagonal phase to a monoclinic phase in a short period of time and, thus, the photocatalytic performance of BiPO4. To complement and rationalize the experimental results, first-principles calculations have been performed within the framework of density functional theory. This was aimed at obtaining the geometric, energetic, and structural parameters as well as vibrational frequencies; further, the electronic properties (band structure diagram and density of states) of the bulk and corresponding surfaces of both the hexagonal and monoclinic phases of BiPO4 were also acquired. A detailed characterization of the low vibrational modes of both the hexagonal and monoclinic polymorphs is key to explaining the irreversible phase transformation from hexagonal to monoclinic. On the basis of the calculated values of the surface energies, a map of the available morphologies of both phases was obtained by using Wulff construction and compared to the observed scanning electron microscopy images. The BiPO4 crystals obtained after 16-32 min of microwave irradiation provided excellent photodegradation of Rhodamine B under visible-light irradiation. This enhancement was found to be related to the surface energy and the types of clusters formed on the exposed surfaces of the morphology. These findings provide details of the hexagonal-to-monoclinic phase transition in BiPO4 during microwave irradiation; further, the results will assist in the design of electronic devices with higher efficiency and reliability.

Electron beam irradiation for the formation of thick Ag film on Ag3PO4.

This study demonstrates that the electron beam irradiation of materials, typically used in characterization measurements, could be employed for advanced fabrication, modification, and functionalization of composites. We developed irradiation equipment using an electron beam irradiation source to be applied in materials modification. Using this equipment, the formation of a thick Ag film on the Ag3PO4 semiconductor is carried out by electron beam irradiation for the first time. This is confirmed by various experimental techniques (X-ray diffraction, field-emission scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy) and ab initio molecular dynamics simulations. Our calculations demonstrate that, at the earlier stages, metallic Ag growth is initiated preferentially at the (110) surface, with the reduction of surface Ag cations forming metallic Ag clusters. As the (100) and (111) surfaces have smaller numbers of exposed Ag cations, the reductions on these surfaces are slower and are accompanied by the formation of O2 molecules.

Association between inflammatory potential of the diet and sleep parameters in sleep apnea patients.

OBJECTIVES: The aim of this study was to analyze the association between the inflammatory potential of diet and sleep parameters in individuals with obstructive sleep apnea (OSA) and to evaluate the sensitivity and specificity of the dietary inflammatory index (DII) at predicting sleep pattern. METHODS: Patients diagnosed with mild to severe OSA were included in the study (N = 296). Sleep pattern was analyzed by polysomnography and subjective sleep parameters. DII scores were calculated from a validated food frequency questionnaire. Receiver operating characteristic curve analysis and generalized linear models were conducted. RESULTS: DII scores were efficient at predicting apnea severity (P < 0.05) and daytime sleepiness (P = 0.02) in age stratification and predicting rapid eye movement latency in obese individuals (P = 0.03). No significant associations were found between DII scores and the majority of sleep parameters. The DII was only associated with daytime sleepiness; patients with a more proinflammatory diet (quintile 4) showed more subjective sleepiness than the group with a more anti-inflammatory diet (quintile 1; P < 0.05). CONCLUSION: Findings from this study indicated that the DII could be sensitive and specific for predicting apnea severity in individuals commonly associated with OSA. Although the DII was not associated with most of the sleep parameters, the few associations found demonstrated the need for more studies that evaluate whether DII is associated with the risk for OSA symptoms.

Eating Late Negatively Affects Sleep Pattern and Apnea Severity in Individuals With Sleep Apnea.

STUDY OBJECTIVES: This study aimed to analyze the association between habitual meal timing and sleep parameters, as well as habitual meal timing and apnea severity in individuals with obstructive sleep apnea (OSA). METHODS: Patients in whom mild to severe OSA was diagnosed were included in the study (n = 296). Sleep parameters were analyzed by polysomnography. Dietary pattern was obtained by a food frequency questionnaire and meal timing of the participants. Individuals with OSA were categorized by meal timing (early, late, and skippers). RESULTS: Dinner timing was associated with sleep latency (ß = 0.130, P = .022), apnea-hypopnea index (AHI) (ß = 1.284, P = .033) and poor sleep quality (ß = 1.140, P = .015). Breakfast timing was associated with wake after sleep onset (WASO) (ß = 3.567, P = .003), stage N1 sleep (ß = 0.130, P < .001), and stage R sleep (ß = -1.189, P = .001). Lunch timing also was associated with stage N1 sleep (ß = 0.095, P = .025), sleep latency (ß = 0.293, P = .001), and daytime sleepiness (ß = 1.267, P = .009). Compared to early eaters, late eaters presented lower duration of stage R sleep and greater values of sleep latency, WASO, stage N1 sleep, and AHI, in addition to increased risk of poor sleep quality and daytime sleepiness (P < .005). CONCLUSIONS: Late meal timing was associated with worse sleep pattern and quality and apnea severity than early meal timing. Despite some of these results having limited clinical significance, they can lead to a better understanding about how meal timing affects OSA and sleep parameters.

Polysomnographic sleep aspects in liver cirrhosis: a case control study.

AIM: To study sleep aspects and parameters in cirrhotic patients and assess the role of liver dysfunction severity in polysomnographic results. METHODS: This was a case-control study. Patients with a diagnosis of liver cirrhosis were consecutively enrolled in the study. Clinical examinations and laboratory liver tests were performed in all patients, and disease severity was assessed using the Child-Pugh score. The control group consisted of age- and gender-matched healthy volunteers. All individuals answered a questionnaire about habits, behaviors, and complaints related to sleep and were submitted to polysomnography. Sleep parameters were compared between the two groups, and separate analyses were performed among classes of Child-Pugh classification in the cirrhotic group. RESULTS: Forty-two cirrhotic patients and forty-two controls were enrolled. Compared to the control group, the cirrhotic group exhibited lower sleep efficiency (mean ± SD: 73.89% ± 14.99% vs 84.43% ± 8.55%, P < 0.01), increased latency (151.27 ± 93.24 min vs 90.62 ± 54.74 min, P < 0.01) and a lower percentage of rapid eye movement (REM) sleep (14.04% ± 5.64% vs 20.71% ± 6.77%, P < 0.05) as well as a higher frequency of periodic limb movements (10.56 ± 2.85/h vs 2.79 ± 0.61/h, P < 0.01). The comparison of sleep parameters among Child A, B and C cirrhotic patients revealed a significant reduction of REM sleep stage occurrence in individuals with severe liver disease (Child C patients) compared to Child A/B patients (polysomnography percentage of REM sleep stage of patients Child A: 16.1% ± 1.2%; Child B: 14.9% ± 1.2%; Child C: 8.6% ± 1.6%, P < 0.05). CONCLUSION: Cirrhosis was associated with shorter sleep time, reduced sleep efficiency, increased sleep latency, increased REM latency and reduced REM sleep. Additionally, disease severity influences sleep parameters.

[Minimal hepatic encephalopathy detection by neuropsychological and neurophysiological methods and the role of ammonia for its diagnosis]. / Detecção de encefalopatia hepática mínima através de testes neuropsicológicos e neurofisiológicos e o papel da amônia no seu diagnóstico.

CONTEXT: Minimal hepatic encephalopathy has been systematically investigated in cirrhotic patients. Although, there are controversies regarding the best methods as well as the role of ammonia for its diagnosis. OBJECTIVE: To evaluate the frequency of minimal hepatic encephalopathy diagnosed by neuropsychological and neurophysiological methods in cirrhotic patients, as well as possible associated risk factors for this condition, including the role of arterial ammonia concentrations for its diagnosis. METHODS: Cirrhotic patients were evaluated by the number connection test parts A and B (NCT-A and NCT-B), and auditory evoked-related potentials (P300). Minimal hepatic encephalopathy was diagnosed by the presence of abnormal P300 and in unless one of the performed neuropsychologic tests. Arterial ammonia concentration, scholarity and cirrhosis severity accessed by Child-Pugh classification were evaluated in all. RESULTS: Forty-eight cirrhotic patients were evaluated, with median age 50 +/- 8 years old, 79% male. The main etiologies were alcoholic and viral. The P300 was abnormal in 75% of cases, while NCT-A and NCT-B were abnormal in 58% and 65%, respectively. The NCT-B results were influenced by scholarity. The minimal hepatic encephalopathy frequency was 50%. Arterial ammonia concentration was not significantly increased in minimal hepatic encephalopathy diagnosed patients (195 +/- 152 mmol/L versus 148 +/- 146 mmol/L; P>0,05). There was no difference between groups with or without minimal hepatic encephalopathy in the other studied variables. CONCLUSION: Minimal hepatic encephalopathy is a frequent condition in cirrhotic patients. The arterial ammonia concentration does not play a major role in its diagnosis.

Detecção de encefalopatia hepática mínima através de testes neuropsicológicos e neurofisiológicos e o papel da amônia no seu diagnóstico / Minimal hepatic encephalopathy detection by neuropsychological and neurophysiological methods and the role of ammonia for its diagnosis

CONTEXTO: A encefalopatia hepática mínima vem sendo sistematicamente investigada em pacientes com cirrose hepática. Entretanto, existem controvérsias quanto aos melhores métodos, bem como o papel da amônia para seu diagnóstico. OBJETIVO: Avaliar a frequência de encefalopatia hepática mínima diagnosticada através de testes neuropsicológicos e neurofisiológicos em cirróticos, bem como os possíveis fatores de risco para esta condição, incluindo o papel da concentração arterial de amônia em seu diagnóstico. MÉTODOS: Indivíduos com cirrose hepática foram avaliados através do teste de conexão numérica partes A e B (TCN-A e TCN-B) e potencial evocado relacionado a eventos (P300). O diagnóstico de encefalopatia hepática mínima foi feito quando da presença de anormalidade no P300 e em, pelo menos, um dos testes neuropsicológicos. As concentrações arteriais de amônia, a escolaridade e a gravidade da cirrose hepática também foram avaliadas em todos. RESULTADOS: Foram avaliados 48 pacientes cirróticos, com média de idade 50 ± 8 anos, sendo 79 por cento do sexo masculino. As principais causas foram a alcoólica e a viral. O P300 foi anormal em 75 por cento dos casos e o TCN-A e TCN-B anormais em 58 por cento e 65 por cento dos casos, respectivamente. Os resultados do TCN-B foram influenciados pela escolaridade. A frequência de encefalopatia hepática mínima foi de 50 por cento. A concentração arterial de amônia não foi significantemente maior em pacientes com diagnóstico de encefalopatia hepática mínima (195 ± 152 mmol/L versus 148 ± 146 mmol/L; P>0,05). Não houve diferença significante entre os grupos com e sem encefalopatia hepática mínima quanto às demais variáveis estudadas. CONCLUSÃO:A encefalopatia hepática mínima é condição frequente em pacientes com cirrose hepática. A concentração arterial de amônia não parece ter papel importante no seu diagnóstico.

CONTEXT: Minimal hepatic encephalopathy has been systematically investigated in cirrhotic patients. Although, there are controversies regarding the best methods as well as the role of ammonia for its diagnosis. OBJECTIVE: To evaluate the frequency of minimal hepatic encephalopathy diagnosed by neuropsychological and neurophysiological methods in cirrhotic patients, as well as possible associated risk factors for this condition, including the role of arterial ammonia concentrations for its diagnosis. METHODS: Cirrhotic patients were evaluated by the number connection test parts A and B (NCT-A and NCT-B), and auditory evoked-related potentials (P300). Minimal hepatic encephalopathy was diagnosed by the presence of abnormal P300 and in unless one of the performed neuropsychologic tests. Arterial ammonia concentration, scholarity and cirrhosis severity accessed by Child-Pugh classification were evaluated in all. RESULTS: Forty-eight cirrhotic patients were evaluated, with median age 50 ± 8 years old, 79 percent male. The main etiologies were alcoholic and viral. The P300 was abnormal in 75 percent of cases, while NCT-A and NCT-B were abnormal in 58 percent and 65 percent, respectively. The NCT-B results were influenced by scholarity. The minimal hepatic encephalopathy frequency was 50 percent. Arterial ammonia concentration was not significantly increased in minimal hepatic encephalopathy diagnosed patients (195 ± 152 mmol/L versus 148 ± 146 mmol/L; P>0,05). There was no difference between groups with or without minimal hepatic encephalopathy in the other studied variables. CONCLUSION: Minimal hepatic encephalopathy is a frequent condition in cirrhotic patients. The arterial ammonia concentration does not play a major role in its diagnosis.

[Evaluation of the event-related potential (ERP-P300) in patients with hepatic cirrhosis without encephalopathy]. / Avaliação dos potenciais evocados relacionados a eventos (ERP-P300) em pacientes com cirrose hepática sem encefalopatia.

BACKGROUND: In hepatic cirrhosis structural liver alterations occur leading to the loss of the organ functions with neuro-psychiatric consequence, as cognitive dysfunctions. One of the most effective ways of objectively evaluating cognition is to measure electrophysiological activity in the central nervous system trough event-related potentials (ERP-P300). AIM: To assess the value of the event-related potential (ERP) in order to determine cognitive disturbances in patients with liver cirrhosis and to assist in the diagnosis of minimal hepatic encephalopathy. METHODS: Fifty patients with liver cirrhosis were selected, without clinical symptoms of hepatic encephalopathy and 35 healthy volunteers, matched by sex and age. The patients were submitted to clinical-neurological and laboratorial examination. The ERP-P300 was performed by the two groups to determine cognitive disturbances. RESULTS: The study showed significant differences between the ERP-P300 latency averages of the two groups. CONCLUSION: The ERP-P300 is simple to use and depends on controllable variables. It is also easy to reproduce and, when properly used, can be useful both to determine cognitive disturbances in patients with hepatic cirrhosis and to assist in minimal hepatic encephalopathy diagnosis.

Avaliação dos potenciais evocados relacionados a eventos (ERP-P300) em pacientes com cirrose hepática sem encefalopatia / Evaluation of the event-related potential (ERP-P300) in patients with hepatic cirrhosis without encephalopathy

RACIONAL: Na cirrose hepática ocorrem alterações na estrutura do fígado, levando à perda das funções do órgão, com conseqüências neuropsiquiátricas, como disfunções cognitivas. Um dos meios mais efetivos para avaliar objetivamente as funções cognitivas é medir a atividade eletrofisiológica do sistema nervoso central através do potencial evocado relacionado a eventos (ERP-P300). OBJETIVO: Estudar a utilidade do potencial evocado relacionado a eventos (ERP), para avaliar distúrbios cognitivos em pacientes com cirrose hepática e como auxiliar no diagnóstico da encefalopatia hepática mínima. MÉTODO: Foram selecionados 50 pacientes, diagnosticados com cirrose hepática sem sinais clínicos de encefalopatia hepática e 35 voluntários saudáveis de idades e sexo semelhantes. Em todos os pacientes foram realizados exames clínico-neurológico e laboratoriais. Para identificação do prejuízo cognitivo foi utilizado o ERP-P300 e obtida a média da latência da onda P300. RESULTADOS: Houve diferença significativa entre as médias da latência do ERP-P300 do grupo cirrótico e controle. CONCLUSÃO: A realização do ERP-P300 é simples, depende de fatores controláveis de variação e tem fácil reprodutibilidade, podendo ser útil para o rastreio de distúrbios cognitivos em pacientes com cirrose e auxiliar no diagnóstico de encefalopatia hepática mínima.

BACKGROUND: In hepatic cirrhosis structural liver alterations occur leading to the loss of the organ functions with neuro-psychiatric consequence, as cognitive dysfunctions. One of the most effective ways of objectively evaluating cognition is to measure electrophysiological activity in the central nervous system trough event-related potentials (ERP-P300). AIM: To assess the value of the event-related potential (ERP) in order to determine cognitive disturbances in patients with liver cirrhosis and to assist in the diagnosis of minimal hepatic encephalopathy. METHODS: Fifty patients with liver cirrhosis were selected, without clinical symptoms of hepatic encephalopathy and 35 healthy volunteers, matched by sex and age. The patients were submitted to clinical-neurological and laboratorial examination. The ERP-P300 was performed by the two groups to determine cognitive disturbances. RESULTS: The study showed significant differences between the ERP-P300 latency averages of the two groups. CONCLUSION: The ERP-P300 is simple to use and depends on controllable variables. It is also easy to reproduce and, when properly used, can be useful both to determine cognitive disturbances in patients with hepatic cirrhosis and to assist in minimal hepatic encephalopathy diagnosis.