A study regarding the anterior cruciate ligament remnant: Differences in balance and postural control between remnant-preserving and remnant-non-preserving patients

Introduction: The anterior cruciate ligament (ACL) is the most frequently injured ligament of the knee. However, quantitative studies on evaluate the postural control influence resulted from the ACL remnant preservation or not are scarce. The aim of this study is to evaluate the postural control of patients submitted to ACL reconstruction with and without preservation of the injured remnant in pre and postoperative periods.MethodsEighteen patients underwent ACL reconstruction and separated into 2 groups according to the preservation or not of the remnant: (I) submitted to ACL reconstruction with preservation of the remnant (10 patients); (II) submitted to ACL reconstruction without preservation of the remnant (8 patients). They were assessed using the Lysholm score and force plate, which evaluated the patient's postural stability for remnant and non-remnant preservation in ACL reconstruction surgery.ResultsGroup I showed statistically significant subjective and objective improvements, both at 3 and 6 months. Additionally, improvement of the Lysholm test at 6 months in Group II was also statistically significant. Furthermore, the results of the Friedman test for the VCOP and VY variables of Group I, with support of the injured side in the force plate, showed a statistically significant difference both for pre and postoperative period at 3 months, compared to the 6-month postoperative period. The variables EAC and VX were statistically different for Group II, considering the preoperative period, 3 and 6 months postoperatively.ConclusionPreserving the ACL remnant in patients with ACL injuries has a positive impact on postural stability during recovery.(AU)

Introducción: El ligamento cruzado anterior (LCA) es el ligamento de la rodilla que se lesiona con mayor frecuencia. Sin embargo, escasean los estudios cuantitativos sobre la evaluación de la influencia del control postural derivada de la preservación, o no, del remanente del LCA. El objetivo de este estudio es evaluar el control postural de los pacientes sometidos a la reconstrucción del LCA, con y sin preservación del remanente lesionado, en los periodos previo y posterior a la cirugía.MétodosDieciocho pacientes sometidos a reconstrucción del LCA separados en 2 grupos, de acuerdo con la preservación o no preservación del remanente: I) sometidos a reconstrucción del LCA con preservación del remanente (10 pacientes), y II) sometidos a reconstrucción del LCA sin preservación del remanente (8 pacientes). Los pacientes fueron evaluados utilizando la puntuación de Lysholm y una placa de aplicación de fuerza, que evaluó la estabilidad postural del paciente para la preservación y no preservación del remanente en la cirugía de reconstrucción del LCA.ResultadosEl grupo I mostró mejoras subjetivas y objetivas estadísticamente significativas, transcurridos 3 y 6 meses. Además, la mejora de la prueba de Lysholm transcurridos 6 meses en el grupo II fue también estadísticamente significativa. Asimismo, los resultados de la prueba de Friedman para las variables VCOP y VY en el grupo I, con apoyo del lado lesionado en la placa de aplicación de fuerza, reflejaron una diferencia estadísticamente significativa en ambos períodos pre y postoperatorio transcurridos 3 meses, en comparación con el período postoperatorio transcurridos 6 meses. Las variables EAC y VX fueron estadísticamente diferentes para el grupo II, considerando el periodo preoperatorio, y los 3 y 6 meses postoperatorios.ConclusiónPreservar el remanente del LCA en los pacientes con lesiones en dicho ligamento tiene un impacto positivo en la estabilidad postural durante la recuperación.(AU)

A study regarding the anterior cruciate ligament remnant: Differences in balance and postural control between remnant-preserving and remnant-non-preserving patients.

INTRODUCTION: The anterior cruciate ligament (ACL) is the most frequently injured ligament of the knee. However, quantitative studies on evaluate the postural control influence resulted from the ACL remnant preservation or not are scarce. The aim of this study is to evaluate the postural control of patients submitted to ACL reconstruction with and without preservation of the injured remnant in pre and postoperative periods. METHODS: Eighteen patients underwent ACL reconstruction and separated into 2 groups according to the preservation or not of the remnant: (I) submitted to ACL reconstruction with preservation of the remnant (10 patients); (II) submitted to ACL reconstruction without preservation of the remnant (8 patients). They were assessed using the Lysholm score and force plate, which evaluated the patient's postural stability for remnant and non-remnant preservation in ACL reconstruction surgery. RESULTS: Group I showed statistically significant subjective and objective improvements, both at 3 and 6 months. Additionally, improvement of the Lysholm test at 6 months in Group II was also statistically significant. Furthermore, the results of the Friedman test for the VCOP and VY variables of Group I, with support of the injured side in the force plate, showed a statistically significant difference both for pre and postoperative period at 3 months, compared to the 6-month postoperative period. The variables EAC and VX were statistically different for Group II, considering the preoperative period, 3 and 6 months postoperatively. CONCLUSION: Preserving the ACL remnant in patients with ACL injuries has a positive impact on postural stability during recovery.

A heuristic-based approach for assessing usability in electric powered wheelchairs: A preliminary investigation.

OBJECTIVE: An important issue related to electric powered wheelchair (EPW) is usability. Recent studies did not use heuristic evaluation and did not consider users' and developers' participation in the usability evaluation process of the EPW, especially when it has to be driven using alternative commands. Thus, this study investigates the use of heuristics to evaluate the usability of EPW driven by alternative commands, considering the opinion of users and assistive technology (AT) development professionals. METHODS: The study was carried out with 54 participants: 28 EPW users (Group I) and 26 AT developers (Group II). We built a set of 25 heuristics that affects EPW usability. Participants rated each of the 25 heuristics according to their importance for the usability of EPW using the five-point Likert scale. We used the R Software to perform the Wilcoxon Mann-Whitney test as a statistical comparisons test between Group I and II. RESULTS: The results showed a statistically significant difference (p<0.05) between Group I and II in the evaluation of 16 heuristics. We identified an important set of heuristics that could help evaluate and improve the usability of EPW. CONCLUSION: The findings highlighted the importance of considering users' and developers' points of view in developing an EPW and its evaluation criteria. It could help the design of the device match the user's needs and expectations. The set of heuristics in this study can be adapted to evaluate other devices' usability using the heuristic evaluation approach.

Energetic Intracloud Lightning in the RELAMPAGO Field Campaign.

A particular strength of lightning remote sensing is the variety of lightning types observed, each with a unique occurrence context and characteristically different emission. Distinct energetic intracloud (EIC) lightning discharges-compact intracloud lightning discharges (CIDs) and energetic intracloud pulses (EIPs)-produce intense RF radiation, suggesting large currents inside the cloud, and they also have different production mechanisms and occurrence contexts. A Low-Frequency (LF) lightning remote sensing instrument array was deployed during the RELAMPAGO field campaign in west central Argentina, designed to investigate convective storms that produce high-impact weather. LF data from the campaign can provide a valuable data set for researching the lightning context of EICs in a variety of subtropical convective storms. This paper describes the production of an LF-CID data set in RELAMPAGO and includes a preliminary analysis of CID prevalence. Geolocated lightning events and their corresponding observed waveforms from the RELAMPAGO LF data set are used in the classification of EICs. Height estimates based on skywave reflections are computed, where prefit residual data editing is used to improve robustness against outliers. Even if EIPs occurred within the network, given the low number of very high-peak current events and receiver saturation, automatic classification of EIPs may not be feasible using this data. The classification of CIDs, on the other hand, is straightforward and their properties, for both positive and negative polarity, are investigated. A few RELAMPAGO case studies are also presented, where high variability of CID prevalence in ordinary storms and high-altitude positive CIDs, possibly in overshooting tops, are observed.

Lightning Geolocation and Flash Rates From LF Radio Observations During the RELAMPAGO Field Campaign.

The lightning data products generated by the low-frequency (LF) radio lightning locating system (LLS) deployed during the Remote sensing of Electrification, Lightning, and Mesoscale/Microscale Processes with Adaptive Ground Observation (RELAMPAGO) field campaign in Argentina provide a valuable data set to research the lightning evolution and characteristics of convective storms that produce high-impact weather. LF LLS data sets offer a practical range for mesoscale studies, allowing for the observation of lightning characteristics of storms such as mesoscale convective systems or large convective lines that travel longer distances which are not necessarily staying in range of regional VHF-based lightning detection systems throughout their lifetime. LF LLSs also provide different information than optical space-borne lightning detectors. Lightning measurements exclusive to LF systems include discharge peak current, lightning polarity, and lightning type classification based on the lightning-emitted radio waveform. Furthermore, these measurements can provide additional information on flash rates (e.g., positive cloud-to-ground flash rate) or narrow bipolar events which may often be associated with dynamically intense convection. In this article, the geolocation and data processing of the LF data set collected during RELAMPAGO is fully described and its performance characterized, with location accuracy better than 10 km. The detection efficiency (DE) of the data set is compared to that of the Geostationary Lightning Mapper, and spatiotemporal DE losses in the LF data set are discussed. Storm case studies on November 10, 2018, highlight the strengths of the data set, which include robust flash clustering and insightful flash rate and peak current measures, while illustrating how its limitations, including DE losses, can be managed.

An Array of Low-Cost, High-Speed, Autonomous Electric Field Mills for Thunderstorm Research.

The atmospheric electric field is an important research parameter in understanding storm electrification and energy exchange between lightning and the atmosphere across the globe. The near-surface electric field can range from a few V/m (order of 10-100 V/m), mainly produced by the currents in the global electric circuit and local charge perturbations, to tens of kV/m in the presence of electrified clouds. The electric field mill (EFM), a variable capacitance electrometer, has been the instrument of choice in the atmospheric electricity community studying phenomena associated with the atmospheric electric field. The EFM is particularly useful in following storm movement and evolution, monitoring the fair-weather electric field at distant locations, and measuring the vertical electric field inside clouds with EFM deployments on balloons. In this paper, we describe a new electric field mill ground-based design, which focuses on lowering the manufacturing and operational costs of doing research with an array of EFM instruments while maintaining the scientific capabilities offered by past designs and commercially available devices. The theory of operation, data processing, and calibration of the instrument are also described. Example data from the first generation of these new field mills, deployed in the RELAMPAGO campaign in Argentina, are presented here. The RELAMPAGO deployment and data set illustrate important strengths of this design, for example, cost, autonomy, longevity, and measurement quality.

Latex sensitization in patients with myelomeningocele: contribution of microarray technique.

Summary: Background. Microarray technique employing molecular allergens is pointed out as a new method to evaluate allergic patients. Objective. To evaluate if microarray technique (ImmunoCAP-ISAC®; I-ISAC®) is similar to fluorescence enzyme immunoassay (FEIA; ImmunoCAP®) in the diagnosis of latex allergy (specific IgE to latex plus symptoms) and latex sensitization (only antibody) in pediatric (9-mo to 14-yrs) patients with myelomeningocele undergone to surgical repair. Methods. Patients underwent skin prick testing (SPT) to latex and food (prick to prick), and dosage of serum specific IgE to latex and recombinant latex allergens (rHev b 1, rHev b 3, rHev b 5, rHev b 6.01, rHev b 6.02, rHev b 8, rHev b 9, and rHev b 11) by ImmunoCAP® and I-ISAC®. Results. The comparison between the two methods showed high level of concordance considering positive and negative results. A statistically significant correlation for rHev b 3 and rHev b 6.01 for the allergic patients, and for rHev b5 and rHev b6.01 for those sensitized to latex, was observed. I-ISAC® is limited to 5 recombinant latex allergens (rHev b 1, 3, 5, 6.01 and 8). Despite the presence of antibodies against pollens, LTP and profilins (I-ISAC®) in some patients, none of them reported symptoms related with intake of fruits and/or vegetables. Conclusion. Both methods are effective in assisting the diagnosis of latex allergy, but differ in the assessment of sensitized pediatric patients with myelomeningocele. The assessment of latex sensitized patients is more complete using the 8 recombinant latex fractions available for ImmunoCAP®, instead of I-ISAC®.

Impact of rest duration on Achilles tendon structure and function following isometric training.

Intervention programs are often sought to strengthen the Achilles tendon (AT) due to its high injury rate. Long rest periods between loading cycles have been found to increase collagen synthesis by tenocytes, suggesting rest duration may be important for tendon adaptation in vivo; however, exercise programs comparing long and short rest duration have not been directly compared. Fourteen adults completed a 12-week progressive training intervention; training sessions consisted of 5×10 isometric plantarflexion contractions each of 3-s duration performed at 90% of MVC three times weekly. Each leg was randomly allocated to long (LRT, 10-s rest) or short rest training (SRT, 3-s rest). We hypothesized that the leg allocated to LRT would demonstrate superior AT collagen organization compared to the leg receiving SRT, which would be related to improved biomechanical function. AT collagen organization and morphology were measured using ultrasound tissue characterization. AT properties were assessed before and after the intervention using a combination of dynamometry, ultrasound imaging, EMG, and motion capture. Contrary to our hypothesis, collagen organization did not improve following either training protocol; conversely, an unexpected decrease in echotype I proportion was seen after SRT (P<.001) but not LRT (P=.58), indicating an apparent protective effect of rest on collagen organization during isometric training. In contrast, AT adaptation was not appreciably enhanced by increasing intercycle rest duration; both protocols were equally effective at inducing significant strength gains and AT mechanical and material adaptation (P≤.001). Further research is necessary to identify optimal loading characteristics for injury prevention and rehabilitation.

Vital signs for children at triage: a multicentre validation of the revised South African Triage Scale (SATS) for children.

OBJECTIVE: To validate a revised version of the paediatric South African Triage Scale (SATS) against admission as a reference standard and compare the sensitivity of triage using: (i) clinical discriminators; (ii) an age-appropriate physiological composite score; and (iii) a combination of both. METHODS: A prospective cohort study was undertaken validating the revised paediatric SATS against outcome markers of children at six emergency centres during a 2-month period in 2011. The primary outcome marker was the proportion of children admitted. Validity indicators including sensitivity (Se), specificity, positive predictive value and negative predictive value (NPV) were used to estimate the validity. Associated percentages for over-/under-triage were used to further assess practical application of the paediatric SATS. RESULTS: A total of 2 014 children were included. The percentage of hospital admissions increased with an increase in the level of urgency from 5% in the non-urgent patients to 73% in the emergency patients. The data demonstrated that sensitivity increased substantially when using the SATS, which is a combination of clinical discriminators and the Triage Early Warning Score (TEWS) (Se 91.0%, NPV 95.3%), compared with use of clinical discriminators in isolation (Se 57.1%, NPV 86.3%) or the TEWS in isolation (Se 75.6%, NPV 89.1%). CONCLUSION: The results of this study illustrate that the revised paediatric SATS is a safe and robust triage tool.

Profile of latex sensitization and allergies in children and adolescents with myelomeningocele in São Paulo, Brazil.

BACKGROUND: Latex allergy is an important cause of occupational allergy. In many countries the prevalence of latex allergy is still high and the profile of latex sensitization is unknown. OBJECTIVES: To evaluate the frequency of sensitization and allergy to latex in children and adolescents with myelomeningocele and to identify associated risk factors. METHODS: The study included 55 children and adolescents with myelomeningocele followed at a specialized center. In addition to a standard questionnaire and skin prick tests (SPTs) to aeroallergens and total latex, the patients underwent determination of total and specific serum IgE to latex and recombinant allergens. RESULTS: We observed a prevalence of 25% for latex sensitization and of 20% for latex allergy. Twenty-four patients (43.6%) were atopic and the average age for the first reaction to latex was 44.5 months. Cutaneous reactions were the most frequently reported reactions (72.7%). Specific immunoglobulin (Ig) E to rHev b 1, rHev b 3, rHev b 5, rHev b 6.1, and rHev b 6.2 was detected in over 50% of patients allergic to latex. Multivariate analysis showed current asthma, atopy, and having undergone 4 or more operations to be risk factors for latex sensitization. CONCLUSIONS: Our study documented a high prevalence of sensitization and allergy to latex in patients with myelomeningocele. Specific IgE to rHev b 1, rHev b 3, rHev b 5, rHev b 6.1, and rHev b 6.2 was detected in over 50% of children and adolescents with myelomeningocele who are allergic to latex. A history of current asthma, atopy, and having undergone 4 or more operations were independent risk factors for latex allergy.

Profile of Latex Sensitization and Allergies in Children and Adolescents With Myelomeningocele in São Paulo, Brazil

Introducción: La alergia al látex constituye una causa importante de alergia ocupacional. En muchos países la prevalencia de alergia al látex es elevada y su perfil de sensibilización desconocido. Objetivos: El objetivo de este estudio fue evaluar la frecuencia de sensibilización y de alergia al látex en niños y adolescentes con mielomeningocele e identificar los factores de riesgo asociados. Métodos: Este estudio evaluó 55 niños y adolescentes afectos de mielomeningocele y monitorizados en un centro especializado. Se realizó un estudio de test cutáneos (prick) frente a aeroalérgenos y látex total. Así como un cuestionario y la determinación de IgE total y específica frente a látex y sus alérgenos recombinantes. Resultados: En los resultados encontramos un 25% de sensibilización y un 20% de alergia al látex. Un 43.6% de los pacientes eran atópicos y la edad media de comienzo de la sintomatología fue de 44.5 meses, siendo las reacciones cutáneas las más frecuentes (72.7%). La IgE específica frente a rHev b 1, 3, 5, 6.1 y 6.2 se detectó en más del 50% de los pacientes alérgicos al látex. El análisis multivariante mostró como significativas las siguientes variables: asma, atopia, y número de cirugías a las que había sido sometido el paciente. Conclusiones: Como conclusión este estudio documenta una elevada prevalencia de sensibilización y alergia al látex en pacientes con mielomeningocele. La IgE específica frente a rHev b 1, 3, 5, 6.1 y 6.2 se detecta en más del 50% de los alérgicos al látex en esta serie. Entre los factores independientes de riesgo para sufrir alergia a látex se encuentran el asma, la atopia y el haber estado sometido a más de cuatro cirugías (AU)

Background: Latex allergy is an important cause of occupational allergy. In many countries the prevalence of latex allergy is still high and the profile of latex sensitization is unknown. Objectives: To evaluate the frequency of sensitization and allergy to latex in children and adolescents with myelomeningocele and to identify associated risk factors. Methods: The study included 55 children and adolescents with myelomeningocele followed at a specialized center. In addition to a standard questionnaire and skin prick tests (SPTs) to aeroallergens and total latex, the patients underwent determination of total and specific serum IgE to latex and recombinant allergens. Results: We observed a prevalence of 25% for latex sensitization and of 20% for latex allergy. Twenty-four patients (43.6%) were atopic and the average age for the first reaction to latex was 44.5 months. Cutaneous reactions were the most frequently reported reactions (72.7%). Specific immunoglobulin (Ig) E to rHev b 1, rHev b 3, rHev b 5, rHev b 6.1, and rHev b 6.2 was detected in over 50% of patients allergic to latex. Multivariate analysis showed current asthma, atopy, and having undergone 4 or more operations to be risk factors for latex sensitization. Conclusions: Our study documented a high prevalence of sensitization and allergy to latex in patients with myelomeningocele. Specific IgE to rHev b 1, rHev b 3, rHev b 5, rHev b 6.1, and rHev b 6.2 was detected in over 50% of children and adolescents with myelomeningocele who are allergic to latex. A history of current asthma, atopy, and having undergone 4 or more operations were independent risk factors for latex allergy (AU)

Reducing electrocardiographic artifacts from electromyogram signals with independent component analysis.

The aim of this work was to reduce ECG artifacts from surface electromyogram (EMG) signals collected from lumbar muscles with the blind source separation technique based on independent component analysis (ICA). Using four EMG signals collected above erector spinal lumbar muscles from 27 subjects, the proposed method fail in separating the sources. However, when considering a single channel of EMG and the same one time-shifted by one sample, the FastICA allowed reducing the signal to ECG noise ratio.

Functional evaluation distinguishes MCI patients from healthy elderly people--the ADCS/MCI/ADL scale.

Patients with MCI may present minor impairments in activities of daily living (ADL). The main objective of this work was to evaluate the ability of two versions of the Alzheimer's Disease Cooperative Study/Activities of Daily Living scale adapted for MCI patients (ADCS/MCI/ADL18 and ADCS/MCI/ADL24) to distinguish patients with MCI from healthy control subjects. Participants were 60 years or older and community dwelling: 31 control subjects, 30 aMCI patients and 33 AD patients. A protocol of neuropsychological tests, global evaluation scales, functional scales, and depressive symptoms assessment was used. Activities of balancing the cheque book, using a telephone, going shopping, taking medication regularly, finding objects, talking about current events, watching television, initiating complex activities, keeping appointments or meetings, reading, getting around outside the home and driving a car were impaired in aMCI patients. The ADCS/MCI/ADL24 scale was better than the ADCS/MCI/ADL18 scale in distinguishing aMCI patients from healthy controls (sensitivity=0.87, specificity=0.87, ROC c=0.887, cut-off point=52/53). The detection of initial functional changes with appropriate scales may contribute to the early diagnosis of MCI and the development of targeted interventions to improve everyday function or prolong independence.

Topographic distribution of the tibial somatosensory evoked potential using coherence

The objective of the present study was to determine the adequate cortical regions based on the signal-to-noise ratio (SNR) for somatosensory evoked potential (SEP) recording. This investigation was carried out using magnitude-squared coherence (MSC), a frequency domain objective response detection technique. Electroencephalographic signals were collected (International 10-20 System) from 38 volunteers, without history of neurological pathology, during somatosensory stimulation. Stimuli were applied to the right posterior tibial nerve at the rate of 5 Hz and intensity slightly above the motor threshold. Response detection was based on rejecting the null hypothesis of response absence (significance level α= 0.05 and M = 500 epochs). The best detection rates (maximum percentage of volunteers for whom the response was detected for the frequencies between 4.8 and 72 Hz) were obtained for the parietal and central leads mid-sagittal and ipsilateral to the stimulated leg: C4 (87 percent), P4 (82 percent), Cz (89 percent), and Pz (89 percent). The P37-N45 time-components of the SEP can also be observed in these leads. The other leads, including the central and parietal contralateral and the frontal and fronto-polar leads, presented low detection capacity. If only contralateral leads were considered, the centro-parietal region (C3 and P3) was among the best regions for response detection, presenting a correspondent well-defined N37; however, this was not observed in some volunteers. The results of the present study showed that the central and parietal regions, especially sagittal and ipsilateral to the stimuli, presented the best SNR in the gamma range. Furthermore, these findings suggest that the MSC can be a useful tool for monitoring purposes.

Topographic distribution of the tibial somatosensory evoked potential using coherence.

The objective of the present study was to determine the adequate cortical regions based on the signal-to-noise ratio (SNR) for somatosensory evoked potential (SEP) recording. This investigation was carried out using magnitude-squared coherence (MSC), a frequency domain objective response detection technique. Electroencephalographic signals were collected (International 10-20 System) from 38 volunteers, without history of neurological pathology, during somatosensory stimulation. Stimuli were applied to the right posterior tibial nerve at the rate of 5 Hz and intensity slightly above the motor threshold. Response detection was based on rejecting the null hypothesis of response absence (significance level alpha= 0.05 and M = 500 epochs). The best detection rates (maximum percentage of volunteers for whom the response was detected for the frequencies between 4.8 and 72 Hz) were obtained for the parietal and central leads mid-sagittal and ipsilateral to the stimulated leg: C4 (87%), P4 (82%), Cz (89%), and Pz (89%). The P37-N45 time-components of the SEP can also be observed in these leads. The other leads, including the central and parietal contralateral and the frontal and fronto-polar leads, presented low detection capacity. If only contralateral leads were considered, the centro-parietal region (C3 and P3) was among the best regions for response detection, presenting a correspondent well-defined N37; however, this was not observed in some volunteers. The results of the present study showed that the central and parietal regions, especially sagittal and ipsilateral to the stimuli, presented the best SNR in the gamma range. Furthermore, these findings suggest that the MSC can be a useful tool for monitoring purposes.

Association of CD14, IL1B, IL6, IL10 and TNFA functional gene polymorphisms with symptomatic dental abscesses.

AIM: To investigate in individuals with symptomatic dental abscesses the occurrence of functional polymorphisms within five genes involved with the immune response. The functional gene polymorphisms analysed were CD14 (-260 C/T), IL1B (+3954 C/T), IL6 (-174 G/C,), IL10 (-1082 G/A) and TNFA (-308 G/A). METHODOLOGY: Genomic DNA obtained from oral swabs from individuals with symptomatic dental abscesses and asymptomatic inflammatory periapical lesions, without previous exacerbation, was submitted to restriction fragment length polymorphism (RFLP) analyses to determine each individual genotype. The chi-square and principal components analysis tests were used for statistical analysis. RESULTS: A significant association was observed between the occurrence of the GG genotype or the G allele expression of the polymorphic locus-174 (G/C) of the IL6 gene, and the presence of the symptomatic dental abscesses in women and in individuals < or =35 years old. The principal components analysis suggested predominance of the symptomatic dental abscesses in individuals displaying: high-producer IL6 genotype; intermediate and high-producer IL1B genotypes and low-producer TNFA genotype. CONCLUSIONS: The present study suggests that genetic factors are associated with susceptibility to develop symptomatic dental abscesses.

Association of interleukin-1beta polymorphism with recurrent aphthous stomatitis in Brazilian individuals.

BACKGROUND: Recurrent aphthous stomatitis (RAS) is characterized by recurrent episodes of oral ulceration in an otherwise healthy individual. Some reports in the literature indicate that RAS may have immunological, psychological, genetic and microbiological bases. The purpose of the present study was to investigate the possible association between interleukin-1beta (IL-1beta) +3954 (C/T) genetic polymorphism and RAS in a sample of Brazilian patients. SUBJECTS AND METHODS: Sixty-two consecutive subjects affected by minor and major forms of RAS and 62 healthy volunteers were genotyped at IL-1beta (+3954). The chi-squared test was used for statistical analysis. RESULTS: A significant increase in the high production of IL-1beta genotype CT was observed in the group with RAS (P = 0.01). After stratifying RAS patients according to the mean number of lesions per episode, a significant difference was only observed between patients with >or=3 lesions in each episode and control. CONCLUSION: There is an increased frequency of polymorphism associated with high IL-1beta production in RAS patients.

Coherence between one random and one periodic signal for measuring the strength of responses in the electro-encephalogram during sensory stimulation.

Coherence between a pulse train representing periodic stimuli and the EEG has been used in the objective detection of steady-state evoked potentials. This work aimed to quantify the strength of the stimulus responses based on the statistics of coherence estimate between one random and one periodic signal, focusing on the confidence limits and power of significance tests in detecting responses. To detect the responses in 95% of cases, a signal-to-noise ratio of about -7.9 dB was required when using 48 windows (M) in the coherence estimation. The ratio, however, increased to -1.2 dB when M was 12. The results were tested in Monte Carlo simulations and applied to EEGs obtained from 14 subjects during visual stimulation. The method showed differences in the strength of responses at the stimulus frequency and its harmonics, as well as variations between individuals and over cortical regions. In contrast to those from the parietal and temporal regions, results for the occipital region gave confidence limits (with M = 12) that were above zero for all subjects, indicating statistically significant responses. The proposed technique extends the usefulness of coherence as a measure of stimulus responses and allows statistical analysis that could also be applied usefully in a range of other biological signals.