Wearable Active Electrode for sEMG Monitoring Using Two-Channel Brass Dry Electrodes with Reduced Electronics.

Gel-based electrodes are employed to record sEMG signals for prolonged periods. These signals are used for the control of myoelectric prostheses, clinical analysis, or sports medicine. However, when the gel dries, the electrode-skin impedance increases considerably. Using dry active electrodes (AEs) to compensate variations of impedance is an alternative for long-term recording. This work describes the optimization of the electronic design of a conventional AE by removing the impedance coupling stage and two filters. The proposed work consisted of 5 stages: electrodes, amplification (X250), 2.2 Vdc offset, low-pass filter, and ADC with USART communication. The device did not need the use of electrolytic gel. The measurements of CMRR (96 dB), amplitude of the output sEMG signal (∼1.6 Vp-p), and system bandwidth (15-450 Hz) were performed in order to confirm the reliability of the device as an sEMG signal acquisition system. The SNR values from seven movements performed by eleven volunteers were compared in order to measure the repeatability of the measurements (average 30.32 dB for a wrist flexion). The SNR for wrist flexion measured with the proposed and the commercial system was compared; the values were 49 dB and 60 dB, respectively.

Prevalence of traffic rule infractions in Cali, Colombia, at sites where injury crashes occurred.

This study aim to determine the proportion of traffic rule infractions in Cali, Colombia, in places where a road traffic injury (RTI) occurred. Description of videotaping of sites where a person was injured in an RTI in 2009. Counts of road users and infractions were established for each road user group and were compared using a Z-test. They were found 13,491 users, distributed as follow: 8.9% were pedestrians, 4.6% cyclists, 24.6% motorcyclists, and 61.8% were automobile drivers. The most frequent traffic violation among motorcyclists was transiting on lines designated for other vehicles (55.2%). Among cyclists, the most frequent violations were transiting without a helmet (99.2%) and not wearing the designated vest (100%). Among pedestrians, crossing streets at prohibited places (77.3%), even at sites where a pedestrian bridge was present (72.7%), represented two common violations. Vulnerable road users committed more traffic infractions than automobile drivers (p < 0.001). High rates of traffic rule infractions among vulnerable road users were observed. Studies to better understand the occurrence of these behaviours and the promotion of effective interventions are warranted.

Experimental Verification of Modeled Thermal Distribution Produced by a Piston Source in Physiotherapy Ultrasound.

Objectives. To present a quantitative comparison of thermal patterns produced by the piston-in-a-baffle approach with those generated by a physiotherapy ultrasonic device and to show the dependency among thermal patterns and acoustic intensity distributions. Methods. The finite element (FE) method was used to model an ideal acoustic field and the produced thermal pattern to be compared with the experimental acoustic and temperature distributions produced by a real ultrasonic applicator. A thermal model using the measured acoustic profile as input is also presented for comparison. Temperature measurements were carried out with thermocouples inserted in muscle phantom. The insertion place of thermocouples was monitored with ultrasound imaging. Results. Modeled and measured thermal profiles were compared within the first 10 cm of depth. The ideal acoustic field did not adequately represent the measured field having different temperature profiles (errors 10% to 20%). Experimental field was concentrated near the transducer producing a region with higher temperatures, while the modeled ideal temperature was linearly distributed along the depth. The error was reduced to 7% when introducing the measured acoustic field as the input variable in the FE temperature modeling. Conclusions. Temperature distributions are strongly related to the acoustic field distributions.

Modeling the thermo-acoustic effects of thermal-dependent speed of sound and acoustic absorption of biological tissues during focused ultrasound hyperthermia.

PURPOSE: To evaluate the effects of thermal dependence of speed of sound (SOS) and acoustic absorption of biological tissues during noninvasive focused ultrasound (US) hyperthermia therapy. METHODS: A finite element (FE) model was used to simulate hyperthermia therapy in the liver by noninvasive focused US. The model consisted of an ultrasonic focused transducer radiating a four-layer biological medium composed of skin, fat, muscle, and liver. The acoustic field and temperature distribution along the layers were obtained after 15 s of hyperthermia therapy using the bio-heat equation. The model solution was found with and without the thermal dependence of SOS and acoustic absorption of biological tissues. RESULTS: The inclusion of the thermal dependence of the SOS generated an increment of 0.4 mm in the longitudinal focus axis of the acoustic field. Moreover, results indicate an increment of the hyperthermia area (zone with temperature above 43 °C), and a maximum temperature difference of almost 3.5 °C when the thermal dependence of absorption was taken into account. CONCLUSION: The increment of the achieved temperatures at the treatment zone indicated that the effects produced by the thermal dependence of SOS and absorption must be accounted for when planning hyperthermia treatment in order to avoid overheating undesired regions.

Prevalence of HLA-B*57:01 allele in Argentinean HIV-1 infected patients.

Hypersensitivity reaction to abacavir (ABC hypersensitivity syndrome, AHS) is strongly associated with the presence of the HLA-B*57:01 allele. This study was designed to estimate the prevalence of HLA-B*57:01 allele in Argentinean HIV-1 infected patients. We analyzed the presence of HLA-B*57:01 allele in 1646 HIV-1 infected patients from different regions of Argentina. This allele was detected in 81 patients; most of them corresponded to patients living in the central region of the country. The prevalence of HLA-B*57:01 was 4.9%, similar to other Caucasian populations and higher than other data reported for South American populations. This strongly supports screening for the presence of HLA-B*57:01 in abacavir treatment of HIV-1 in our country.

Limb amputation among patients with surgically treated popliteal arterial injury: analysis of 15 years of experience in an urban trauma center in Cali, Colombia.

BACKGROUND: Popliteal arterial injuries carry a high risk of amputation. The currently available literature from both civilian and military experiences is characterized by a wide variation of recommendations for surgical management. We questioned how these recommendations have been applied in our practice. Therefore, we aimed to identify predictors of amputation after popliteal arterial injury. METHODS: We conducted an observational study of 175 patients with popliteal arterial injuries who underwent surgical treatment from 1992 to 2006 at a level I trauma center in Cali, Colombia. Information on demographic characteristics, clinical information, and surgical management was collected from clinical records. The outcome measure was amputation within 30 days following the first surgical intervention. RESULTS: The amputation rate was 17.1%. A multivariable logistic regression model indicates that blunt mechanism (odds ratio [OR] 4.79, 95% confidence interval [CI] 1.49-15.42), signs of ischemia (OR 5.29, 95% CI 1.48-18.91), ligation of the popliteal vein of the compromised limb during surgical exploration (OR 3.83, 95% CI 1.20-12.18), and the development of arterial thrombosis (OR 56.51, 95% CI 12.36-258) were found to be independent predictors of amputation. Fractures, popliteal venous injuries, prolonged time between injury and surgery, fasciotomies, and graft arterial repair were not statistically significant predictors of amputation. CONCLUSIONS: Emphasis on the early assessment and prompt identification of signs of ischemia after popliteal arterial injury continue to be the most important factor for reducing the risk of amputation, especially in blunt trauma. Vascular trauma teams must emphasize the need for the specialized management of popliteal veins. Clinical research is needed in order to identify means of decreasing arterial thrombosis after popliteal repair.

Therapy ultrasound equipment characterization: Comparison of three techniques.

Methods for characterizing ultrasonic therapy equipment rapidly and easily have to be implemented in order to avoid damages to patients; the existent methods measure different parameters in the ultrasonic beam that can be used to determine if the equipment works appropriately. In this paper, a comparison of three methods to characterize the ultrasonic beam is presented. The first one is a C-scan with microprobe which uses a hydrophone for measuring the signal and a positioning system. The second method is the IR-thermography which uses a phantom to absorb the ultrasonic energy and to convert it into heat. Here, the heat distribution is obtained with an IR camera. The third method uses a sheet of thermochromic liquid crystals (TLC) as sensor and a phantom to absorb the energy. The heat distribution is obtained with a normal camera because the TLCs change their color as a function of temperature. The results indicate that each technique has its own benefits, but the most important parameters can be obtained with only one of them.

The US National Violent Death Reporting System: domestic and international lessons for violence injury surveillance.

OBJECTIVES: This article reviews and comments on the development, strengths and limitations of the US National Violent Death Reporting System (NVDRS) from a variety of domestic and international perspectives. METHODS: The authors were provided preliminary copies of the manuscripts in this special edition and examined them to understand and put in context the elements and uses of the NVDRS so far. Their comments are based on their reading and interpretation of these papers plus their own combined experience in injury and public health surveillance from four different countries: the US, Colombia, Australia, and South Africa. RESULTS: The NVDRS is bigger than the sum of its parts because it links existing data from multiple sources. Its adoption of modern relational database technologies offers advantages over traditional injury surveillance databases and creates new opportunities for understanding, collaboration, and partnerships. Challenges include overcoming resource limitations so that it can become a truly national system, measuring and improving its sensitivity and comparability, and the need to examine mortality in context with serious non-fatal violent events. CONCLUSIONS: The NVDRS is an important work in progress for the US. Each country should examine its own needs, traditions, resources, and existing infrastructure when deciding what kind of violence surveillance system to develop. However, collaboration in developing common definitions and classifications provides an important foundation for international comparisons.

Variable drug metabolism genes in Arab population.

Cataloging interethnic differences in the distribution of genotypes of drug metabolic genes provides valuable information for profiling the pharmacogenetics of a population. We used PCR analysis to catalog the frequencies of alleles and genotypes for CYP1A1, NAT2, GSTs, MTHFR, MTR (MS) and NQO*1 in Arabs. The frequencies of alleles and/or genotypes for CYP1A1*2A, GSTT1 null, GSTT1 and GSTM1 double null, and GSTP1 A1578G in Arabs were significantly higher than those reported in Caucasians. However, the distribution of NAT2 acetylator phenotypes in both populations was similar. In contrast, the frequencies of MTHFR 677T allele and the combined (677+1298) genotypes for low activity were lower than those reported in Caucasians. Other alleles in Arabs, including CYP1A1 T3801C and GSTP1 A1578G were present in frequencies similar to Africans. The overall profile of variations in metabolism genes in Arabs is thus unique.

Paucity of TEL-AML 1 translocation, by multiplex RT-PCR, in B-lineage acute lymphoblastic leukemia (ALL) in Indian patients.

A total of 69 patients of B lineage ALL, 35 children (32 males, 3 females) and 34 young adults (27 males, 7 females) were studied by multiplex RT-PCR to determine the relative frequency of t(9;22), t(12;21), t(1;19), and t(4;11,). Translocation (9;22) was seen in 1/35 (2.8%) and t(1;19) in 2/35 (5.7%) children. None of the children showed t(12;21) and t(4;11) translocations. In young adults, t(9;22) and t(1;19) were seen in 5/34 (14.7%) and 2/34 (5.8%) patients, respectively. None of the latter showed t(12;21) or t(4;11) translocations. Thus, there appears to be a significant under representation of the fusion transcripts for TEL-AML, a good prognostic marker, in this study, unlike in the West, where it is seen in 35% of children with ALL. This, together with the generally increased leukemic burden seen in Indian patients, may explain in part, the poor treatment outcome reported.

Quantitative expression of TEL in childhood acute lymphoblastic leukemia.

Loss of heterozygosity of chromosome 12p in human precursor B-cell ALL invariably results in loss of TEL coding sequences. Accompanied by a 12;21 translocation, such loss of heterozygosity ensures complete loss of the wild-type TEL. No inactivating mutations of the retained TEL allele have been reported in leukemias with hemizygous deletion. However, only minimal data reported the expression of the wild-type TEL in ALL. We now demonstrate that quantitative real-time RT-PCR from leukemic RNA samples could be indicative of compromised TEL expression in childhood ALL and therefore loss of TEL function.

Concurrent methylation of multiple genes in childhood ALL: Correlation with phenotype and molecular subgroup.

Multiple genes have been shown to be independently hypermethylated in lymphoid malignancies. We report here on the extent of concurrent methylation of E-cadherin, Dap-kinase, O(6)MGMT, p73, p16, p15 and p14 in 129 pediatric ALL cases. While most of these genes demonstrated methylation in a proportion of cases, O(6)MGMT, p16 and p14 were infrequently methylated (11, 7 and 3%, respectively). Methylation of at least one gene was found in the vast majority (83%) of cases. To determine the extent and concordance of methylation we calculated a methylation index (MI=number of methylated genes/number of studied genes) for each sample. The average MI was 0.28, corresponding to 2/7 methylated genes. MI was correlated with standard prognostic factors, including immunophenotype, age, sex, WBC and presence of specific translocations (TEL-AML1, BCR-ABL, E2A-PBX1 or MLL-AF4). We determined that children >/=10 years old and children presenting with high WBC (>/=50 x 10(9)/l) both associated with a higher MI (P<0.01 and <0.05, respectively). T-ALLs demonstrated a lower MI (median=0.17) than precursor B ALLs (median=0.28). Among the different molecular subgroups, MLL-ALLs had the highest MI (mean=0.35), while ALLs carrying the t(1;19) had the lowest MI (mean=0.07). The most common epigenetic lesion in childhood ALL was methylation of E-cadherin (72%) independent of the molecular subtype or other clinicopathological factors.

Clinical significance of the arthroscopic drive-through sign in shoulder surgery.

PURPOSE: During arthroscopy of the shoulder, the ability to pass the arthroscope easily between the humeral head and the glenoid at the level of the anterior band of the inferior glenohumeral ligament is considered a positive drive-through sign. The drive-through sign has been considered diagnostic of shoulder instability and has been associated with shoulder laxity and with SLAP lesions. The goal of this study was to examine the prevalence of the drive-through sign in patients undergoing shoulder arthroscopy and to determine its relationship to shoulder instability, shoulder laxity, and to SLAP lesions. TYPE OF STUDY: Case series. METHODS: We prospectively studied 339 patients undergoing arthroscopy of the shoulder for a variety of diagnosis from 1992 to 1998. The drive-through sign was performed with the patients in a lateral decubitus position and under general anesthesia. The drive-through sign was correlated with preoperative physical findings, intraoperative laxity testing, and with intra-articular pathology at the time of arthroscopy. RESULTS: The arthroscopic evaluation showed that drive-through sign was positive in 234 (69%) shoulders. For the diagnosis of instability, the drive-through sign had a sensitivity of 92%, a specificity of 37. 6%, a positive predictive value of 29.9%, a negative predictive value of 94.2%, and an overall accuracy of 49%. There was an association between the drive-through sign and increasing shoulder laxity, but not with SLAP lesions. CONCLUSIONS: This study shows that a positive drive-through sign is not specific for shoulder instability but is associated with shoulder laxity. This arthroscopic sign should be incorporated with other factors when considering the diagnosis of instability.

Association of EBV strains, defined by multiple loci analyses, in non-Hodgkin lymphomas and reactive tissues from HIV positive and HIV negative patients.

Epstein-Barr virus (EBV) associated with lymphoid neoplasms demonstrates preferential association with certain viral strains. Previous subtyping studies have however been confined to analysis of sequence variability within a single locus in EBV. Variations have now been reported for several latently expressed EBV genes, including, EBNAs-1, 2 and LMP-1. Variant EBNA-1 strains have been identified in Burkitt's lymphomas and clustering of subtypes for LMP and EBNA-2 have been associated with either malignancy and/or clinical disease. To investigate the linkage between the variability in these three loci in EBV associated with lymphoid malignancies, we subclassified EBV-associated lymphoproliferations (9 reactive and 24 malignant) from HIV-negative and HIV-positive patients by analysis of the EBNA-1, LMP1, and EBNA-2 genes. Our results demonstrate that (1) EBV identical to the prototype B95.8 strain (Type 1 EBNA-2, wild type EBNA-1 and LMP-1) is very rarely associated with tumors. (2) The EBNA-1 variant V-leucine, restricted to malignant lymphomas in immunocompetent patients, was readily identified in non-malignant lesions in HIV infected patients. (3) Variations of EBNA-1 occur independent of variations at other loci.

Parenting and physical punishment: primary care interventions in Latin America.

Physical punishment is a form of intrafamilial violence associated with short- and long-term adverse mental health outcomes. Despite these possible consequences, it is among the most common forms of violent interpersonal behavior. For many children it begins within the first year of life. The goal of this study was to determine the feasibility of involving public sector primary health care providers to inform parents about alternatives to physical punishment. The study used a qualitative design utilizing focus groups and survey questionnaires with parents and providers at six clinic sites chosen to be representative of public sector practice settings in Costa Rica and in metropolitan Santiago, Chile. The data were collected during 1998 and 1999. In the focus groups and surveys the parents voiced a range of opinions about physical punishment. Most acknowledged its common use but listed it among their least preferred means of discipline. Frequency of its use correlated positively with the parents' belief in its effectiveness and inversely with their satisfaction with their children's behavior. Some parents wanted to learn more about discipline; others wanted help with life stresses they felt led them to use physical punishment. Parents reported they chose other family members more frequently as a source of parenting information than they did health care providers. Some parents saw providers as too rushed and not knowledgeable enough to give good advice. Providers, in turn, felt ill equipped to handle parents' questions, but many of the health professionals expressed interest in more training. Parents and providers agreed that problems of time, space, and resources were barriers to talking about child discipline in the clinics. Many parents and providers would welcome a primary-care-based program on physical punishment. Such a program would need to be customized to accommodate local differences in parent and provider attitudes and in clinic organization. Health care professionals need more training in child discipline and in the skills required to interact with parents on issues relating to child behavior.

[Allergic rhinitis. Current symptoms]. / Rinitis alérgica. Síntomas actuales.

BACKGROUND: Whatever disease whose etiology is determined by environment should have a periodic check-up for etiologic agents especially for the group of symptoms that accompanies it's clinical features. The purpose of this research is to check if the classic symptomatology described in Allergic Rhinitis (AR) corresponds to the pre: reality or need some modifications in it's diagnostic interpretation. MATERIAL AND METHOD: For this we evaluated in a period of ninety days 438 patients. RESULTS: Both children and adults 58.22% females and 41.78% males aged between seven months and 67 years), who have AR. The highest level of occurrence by was between 5 and 9 years (23.5%. Symptomatology rhinorrea 91.32%, nasal congestion 87.89%, continuous sneezing 84.93%, nasal itching 81.27%, epistaxis 23.74% and nasal. Dryness 22.15%. CONCLUSION: We have found in AR that the vasomotor phenomena and anatomic-vascular lesions are increasing in the affected people who are born in Mexico City and those who have resided for at least five years in Mexico City and it's vicinity.

Association of Burkitt's lymphoma with the Epstein-Barr virus in two developing countries.

The clinical presentation of Burkitt's lymphoma (BL) and it's association with the Epstein-Barr virus (EBV) varies in different geographic areas, BL in developing countries being "intermediate" between the sporadic and endemic types, both in it's clinical presentation and it's association with EBV, which varies from 25-80%. In this study we have analysed the clinical features, EBV association, subtype and prevalence of the deleted variant of the Latent Membrane Protein-1 (LMP-1) of EBV in forty-two cases from two developing countries- India (n = 25) and Argentina (n = 17). In both countries the abdomen was the site most commonly involved while jaw involvement was rare. EBV was detected by in-situ hybridization using the EBER-1 RNA probe. 47% of cases from Argentina and 80% of cases from India were EBER positive. EBV typing using EBNA-3C primers showed a predominance of Type A in both countries (India-13/16 and Argentina-(7/8)). The 30bp deletion of the LMP-1 gene was detected in all evaluated cases from Argentina while the wild type of the gene was seen in all the evaluable Indian cases. Our study highlights the similarities and differences in the clinical presentation and EBV association of BL in two developing countries and also indicates that the subtype of EBV and prevalence of the LMP-1 deletion may reflect the predominant subtype in a particular population.

E2F family members are differentially regulated by reversible acetylation.

The six members of the E2F family of transcription factors play a key role in the control of cell cycle progression by regulating the expression of genes involved in DNA replication and cell proliferation. E2F-1, -2, and -3 belong to a structural and functional subfamily distinct from those of the other E2F family members. Here we report that E2F-1, -2, and -3, but not E2F-4, -5, and -6, associate with and are acetylated by p300 and cAMP-response element-binding protein acetyltransferases. Acetylation occurs at three conserved lysine residues located at the N-terminal boundary of their DNA binding domains. Acetylation of E2F-1 in vitro and in vivo markedly increases its binding affinity for a consensus E2F DNA-binding site, which is paralleled by enhanced transactivation of an E2F-responsive promoter. Acetylation of E2F-1 can be reversed by histone deacetylase-1, indicating that reversible acetylation is a mechanism for regulation also of non-histone proteins.