Study of the Myocardial Contraction and Relaxation Velocities through Doppler Tissue Imaging Echocardiography: A New Alternative in the Assessment of the Segmental Ventricular Function

OBJECTIVE: Doppler tissue imaging (DTI) enables the study of the velocity of contraction and relaxation of myocardial segments. We established standards for the peak velocity of the different myocardial segments of the left ventricle in systole and diastole, and correlated them with the electrocardiogram. METHODS: We studied 35 healthy individuals (27 were male) with ages ranging from 12 to 59 years (32.9 ± 10.6). Systolic and diastolic peak velocities were assessed by Doppler tissue imaging in 12 segments of the left ventricle, establishing their mean values and the temporal correlation with the cardiac cycle. RESULTS: The means (and standard deviation) of the peak velocities in the basal, medial, and apical regions (of the septal, anterior, lateral, and posterior left ventricle walls) were respectively, in cm/s, 7.35(1.64), 5.26(1.88), and 3.33(1.58) in systole and 10.56(2.34), 7.92(2.37), and 3.98(1.64) in diastole. The mean time in which systolic peak velocity was recorded was 131.59ms (±19.12ms), and diastolic was 459.18ms (±18.13ms) based on the peak of the R wave of the electrocardiogram. CONCLUSION: In healthy individuals, maximum left ventricle segment velocities decreased from the bases to the ventricular apex, with certain proportionality between contraction and relaxation (P<0.05). The use of Doppler tissue imaging may be very helpful in detecting early alterations in ventricular contraction and relaxation.

Assessment of a two-step nucleic acid amplification assay for detection of Neisseria meningitidis followed by capsular genogrouping

Immediate prevention of meningococcal disease relies in part on the prompt treatment with antibiotics of household and other close contacts of cases; however intervention with effective vaccination relies on identification of serogroup-causing strains. Parenteral antibiotic for patient with suspected meningococcal disease before hospital admission is currently recommended. Laboratory standard methods are hindered by failure to detect bacteria by this medical approach to improve patient prognosis. We assessed two polymerase chain reaction (PCR) assays to detect (crgA) and define the serogroups (siaD, orf-2, and ctrA) of Neisseria meningitidis in 120 cerebrospinal fluid (CSF) samples from positive cases (culture or antigen detection or direct smear). The PCR sensitivity for the identification of N. meningitidis was 100% (95% confidence interval, CI, 96-100%) compared to a sensitivity of 46% for culture (95% CI 37-55%), 61% for latex agglutination test (95% CI 52-70%), and 68% for Gram stain (95% CI 59-76%); PCR specificity was 97% (95% CI 82-100%). PCR correctly identified the serogroups A, B, C, W135, Y, and X in CSF samples with a sensitivity of 88% (95% CI 80-93%); the primer sets were 100% specific. The introduction of PCR-based assays shall increase laboratory confirmed cases, consequently enhancing surveillance of meningococcal disease.

Assessment of a DNA vaccine encoding an anchored-glycosylphosphatidylinositol tegumental antigen complexed to protamine sulphate on immunoprotection against murine schistosomiasis

Protamine sulphate/DNA complexes have been shown to protect DNA from DNase digestion in a lipid system for gene transfer. A DNA-based vaccine complexed to protamine sulphate was used to induce an immune response against Schistosoma mansoni anchored-glycosylphosphatidylinositol tegumental antigen in BALB/c mice. The protection elicited ranged from 33 to 44%. The spectrum of the elicited immune response induced by the vaccine formulation without protamine was characterized by a high level of IgG (IgG1> IgG2a). Protamine sulphate added to the DNA vaccine formulation retained the green fluorescent protein encoding-plasmid longer in muscle and spleen. The experiments in vivo showed that under protamine sulphate effect, the scope of protection remained unchanged, but a modulation in antibody production (IgG1= IgG2a) was observed.

Usefulness of PCR-based assays to assess drug efficacy in Chagas disease chemotherapy: value and limitations

One major goal of research on Chagas disease is the development of effective chemotherapy to eliminate the infection from individuals who have not yet developed cardiac and/or digestive disease manifestations. Cure evaluation is the more complex aspect of its treatment, often leading to diverse and controversial results. The absence of reliable methods or a diagnostic gold standard to assess etiologic treatment efficacy still constitutes a major challenge. In an effort to develop more sensitive tools, polymerase chain reaction (PCR)-based assays were introduced to detect low amounts of Trypanosoma cruzi DNA in blood samples from chagasic patients, thus improving the diagnosis and follow-up evaluation after chemotherapy. In this article, I review the main problems concerning drug efficacy and criteria used for cure estimation in treated chagasic patients, and the work conducted by different groups on developing PCR methodologies to monitor treatment outcome of congenital infections as well as recent and late chronic T. cruzi infections.

Assessing key safety concerns of a Wolbachia-based strategy to control dengue transmission by Aedes mosquitoes

Mosquito-borne diseases such as dengue fever, chikungunya or malaria affect millions of people each year and control solutions are urgently needed. An international research program is currently being developed that relies on the introduction of the bacterial endosymbiont Wolbachia pipientis into Aedes aegypti to control dengue transmission. In order to prepare for open-field testing releases of Wolbachia-infected mosquitoes, an intensive social research and community engagement program was undertaken in Cairns, Northern Australia. The most common concern expressed by the diverse range of community members and stakeholders surveyed was the necessity of assuring the safety of the proposed approach for humans, animals and the environment. To address these concerns a series of safety experiments were undertaken. We report in this paper on the experimental data obtained, discuss the limitations of experimental risk assessment and focus on the necessity of including community concerns in scientific research.

Evaluation of parasitological and molecular techniques for the diagnosis and assessment of cure of schistosomiasis mansoni in a low transmission area

This study evaluated parasitological and molecular techniques for the diagnosis and assessment of cure of schistosomiasis mansoni. A population-based study was performed in 201 inhabitants from a low transmission locality named Pedra Preta, municipality of Montes Claros, state of Minas Gerais, Brazil. Four stool samples were analysed using two techniques, the Kato-Katz® (KK) technique (18 slides) and the TF-Test®, to establish the infection rate. The positivity rate of 18 KK slides of four stool samples was 28.9% (58/201) and the combined parasitological techniques (KK+TF-Test®) produced a 35.8% positivity rate (72/201). Furthermore, a polymerase chain reaction (PCR)-ELISA assay produced a positivity rate of 23.4% (47/201) using the first sample. All 72 patients with positive parasitological exams were treated with a single dose of Praziquantel® and these patients were followed-up 30, 90 and 180 days after treatment to establish the cure rate. Cure rates obtained by the analysis of 12 KK slides were 100%, 100% and 98.4% at 30, 90 and 180 days after treatment, respectively. PCR-ELISA revealed cure rates of 98.5%, 95.5% and 96.5%, respectively. The diagnostic and assessment of cure for schistosomiasis may require an increased number of KK slides or a test with higher sensitivity, such as PCR-ELISA, in situations of very low parasite load, such as after therapeutic interventions.

New host, geographic records, and histopathologic studies ofAngiostrongylus spp (Nematoda: Angiostrongylidae) in rodents from Argentina with updated summary of records from rodent hosts and host specificity assessment

To date, 21 species of the genus Angiostrongylus (Nematoda: Angiostrongylidae) have been reported around the world, 15 of which are parasites of rodents. In this study, new host, geographic records, and histopathologic studies of Angiostrongylus spp in sigmodontine rodents from Argentina, with an updated summary of records from rodent hosts and host specificity assessment, are provided. Records of Angiostrongylus costaricensis from Akodon montensis andAngiostrongylus morerai from six new hosts and geographical localities in Argentina are reported. The gross and histopathologic changes in the lungs of the host species due to angiostrongylosis are described. Published records of the genus Angiostrongylus from rodents and patterns of host specificity are presented. Individual Angiostrongylusspecies parasitise between one-19 different host species. The most frequent values of the specificity index (STD) were between 1-5.97. The elevated number of host species (n = 7) of A. morerai with a STD = 1.86 is a reflection of multiple systematic studies of parasites from sigmodontine rodents in the area of Cuenca del Plata, Argentina, showing that an increase in sampling effort can result in new findings. The combination of low host specificity and a wide geographic distribution of Angiostrongylus spp indicates a troubling epidemiological scenario although, as yet, no human cases have been reported.

Tele-education and competencies assessment to Brazilian's auxiliary nurse

This paper presents Brazilian's experience with the organization of methods and strategies for the assessment of competencies for technical level of nursing workers. The evaluative process proposed includes the creation of a learning-oriented and distance-based virtual assessment environment. The proposed methodology for professional competencies assessment adopted a critical-emancipatory perspective. A tele-education environment was deployed, involving software development - a virtual man - and an assessment cybertutor. Learning modules for the cybertutor were developed and videos of clinical simulations, structured around assessment in cognitive, behavioral, and simulation areas. The evaluation modules considered aspects of competencies in know-know, know-how and know-act professional ethics. Also the variability of practices of nursing - hospitals and primary health care units - was considered. This instrument showed as an important strategy for the optimization of assessment procedures that are widely used across Brazil and it is a powerful tool for incorporation into the continuing professional education.

Assessment of the soil compaction of two ultisols caused by logging operations

The impact of wood loads on bulk density and preconsolidation pressure and of harvester and forwarder traffic on rut depth, bulk density and preconsolidation pressure of two Ultisols were examined in this study. Our objective was to quantify the threshold beyond which significant soil compaction and rutting would occur. This study was carried out in the county of Eunápolis, state of Bahia, Brazil, (16 º 23 ' 17 '' S and 39 º 10 ' 06 '' W; altitude 80 m asl) in two Ultisols (PAd2 and PAd3) with different texture classes, in experimental areas with eucalypt plantation. The study involved measurements at the wood load site and machine driving at specific locations in the forest during logging operations. The treatments consisted of one harvester pass and, 8, 16 and 40 passes of a fully loaded forwarder. Thresholds were established based on the rut depth and percentage of preconsolidation pressure values in the region of additional soil compaction defined in the bearing capacity model. The percentage of soil samples with values of preconsolidation pressure in the region of additional soil compaction indicated a greater susceptibility of PAd3 than of PAd2 to soil compaction. The threshold levels established here based on preconsolidation pressure and rut depth indicated that no more than eight forwarder passes should be allowed in loading operations in order to minimize soil compaction.

Assessment of Efficiency and Adequacy of Retention Terraces

Due to losses caused by water erosion, the development of techniques that increase the efficiency of soil conservation practices is fundamental. Terracing of agricultural lands is an important conservation practice. Bearing in mind that improperly built terraces may negatively affect the landscape, the purpose of this work was to evaluate the efficiency as well as the adequacy of retention terraces. Assessments were performed in four terraces implanted in different states, all located in the mideastern region of the state of Minas Gerais. The water storage efficiency of the terraces was determined by comparing the effective with the required storage capacity, as established in the project. Proposals were also made for the adequacy of the assessed terraces, based on the correction of the characteristics that jeopardized storage efficiency. The storage efficiency of three of the four assessed terraces was below the required levels (0.5-13 %). The main properties influencing storage capacity were: uniformity of ridge crest height, terrace end closure, and the cross section finishing. In two of the three low-efficiency terraces, the correction of these characteristics proved sufficient to raise the storage efficiency to nearly 100 %.

Soil infiltration based on bp neural network and grey relational analysis

Soil infiltration is a key link of the natural water cycle process. Studies on soil permeability are conducive for water resources assessment and estimation, runoff regulation and management, soil erosion modeling, nonpoint and point source pollution of farmland, among other aspects. The unequal influence of rainfall duration, rainfall intensity, antecedent soil moisture, vegetation cover, vegetation type, and slope gradient on soil cumulative infiltration was studied under simulated rainfall and different underlying surfaces. We established a six factor-model of soil cumulative infiltration by the improved back propagation (BP)-based artificial neural network algorithm with a momentum term and self-adjusting learning rate. Compared to the multiple nonlinear regression method, the stability and accuracy of the improved BP algorithm was better. Based on the improved BP model, the sensitive index of these six factors on soil cumulative infiltration was investigated. Secondly, the grey relational analysis method was used to individually study grey correlations among these six factors and soil cumulative infiltration. The results of the two methods were very similar. Rainfall duration was the most influential factor, followed by vegetation cover, vegetation type, rainfall intensity and antecedent soil moisture. The effect of slope gradient on soil cumulative infiltration was not significant.

ASSESSMENT OF BIOAVAILABILITY OF HEAVY METALS AFTER VERMICOMPOSTING IN THE PRESENCE OF ELECTRONIC WASTE

ABSTRACT Heavy metals contained in electronic waste, if discarded improperly, can become bioavailable after vermicomposting, posing a risk to the environment. Small-scale vermicomposting experiments were carried out with printed circuit boards (PCBs) to investigate the migration of heavy metals (Cu, Pb, Zn, Ni, and Sn) to the final compost, as well as the mobility and bioavailability of these metals. High total levels of Pb, Sn and Cu in samples of manure with electronic waste (MEW) and vegetables with electronic waste (VEW) were detected. Based on the initial metal levels in the PCBs and their concentration in the resulting compost, the order of migration of these metals to the MEW and VEW samples was Sn (23.1 %)>Pb (18.4 %)>Ni (4.63 %)>Zn (0.46 %)>Cu (0.14 %) and Sn (24.3 %)>Pb (23.6 %)>Ni (11.33 %)>Zn (1.76 %)>Cu (0.60 %), respectively. Mobility and bioavailability of these metals in the compost were evaluated by three-stage sequential extraction, where F1 was the exchangeable fraction, F2 the organic fraction and F3 the residual fraction. The bioavailability factor (BF) was calculated by the ratio of the sum of fractions F1 and F2 divided by the total sum of the fractions (F1 + F2 + F3). The highest bioavailability factor (BF = 0.92) was found for Pb, the heavy metal considered the greatest environmental concern in this study, indicating the high mobility and the possibility of becoming bioavailable of this metal.

Selection of bee species for environmental risk assessment of GM cotton in the Brazilian Cerrado

The objective of this work was to list potential candidate bee species for environmental risk assessment (ERA) of genetically modified (GM) cotton and to identify the most suited bee species for this task, according to their abundance and geographical distribution. Field inventories of bee on cotton flowers were performed in the states of Bahia and Mato Grosso, and in Distrito Federal, Brazil. During a 344 hour sampling, 3,470 bees from 74 species were recovered, at eight sites. Apis mellifera dominated the bee assemblages at all sites. Sampling at two sites that received no insecticide application was sufficient to identify the three most common and geographically widespread wild species: Paratrigona lineata, Melissoptila cnecomola, and Trigona spinipes, which could be useful indicators of pollination services in the ERA. Indirect ordination of common wild species revealed that insecticides reduced the number of native bee species and that interannual variation in bee assemblages may be low. Accumulation curves of rare bee species did not saturate, as expected in tropical and megadiverse regions. Species-based approaches are limited to analyze negative impacts of GM cotton on pollinator biological diversity. The accumulation rate of rare bee species, however, may be useful for evaluating possible negative effects of GM cotton on bee diversity.

Assessment on nutrient levels in the aerial biomass of irrigated guava in São Francisco Valley, Brazil

In perennial crops, fertilizers are applied to restore the amount of nutrient removed from the plant by harvesting. Nevertheless, the immobilized nutrient inside the whole plant should be considered. Based on it, the nutrient concentrations in the guava leaf and fruit and the nutrient contents removed by fruits and post-harvest pruning were evaluated in an irrigated orchard, in Petrolina, State of Pernambuco, Brazil. The greatest contents removed by fruits were N and K among the macronutrients, while Fe, Zn and Mn presented higher levels among the micronutrients. More than 60% of the total content of N, P, K, Mg, Fe, and B removed by pruning were immobilized in the leaf and non-marketable fruit.