The use of Artificial Intelligence in predicting Respiratory Syncytial Virus-inhibiting flavonoids

Human Respiratory Syncytial Virus (hRSV) infection results in death and hospitalization of thousands of people worldwide each year. Unfortunately, there are no vaccines or specific treatments for hRSV infections. Screening hundreds or even thousands of promising molecules is a challenge for science. We integrated biological, structural, and physicochemical properties to train and to apply the concept of artificial intelligence (AI) able to predict flavonoids with potential anti-hRSV activity. During the training and simulation steps, the AI produced results with hit rates of more than 83%. The better AIs were able to predict active or inactive flavonoids against hRSV. In the future, in vitro and/or in vivo evaluations of these flavonoids may accelerate trials for new anti-RSV drugs, reduce hospitalizations, deaths, and morbidity caused by this infection worldwide, and be used as input in these networks to determine which parameter is more important for their decision.

Estimating genetic parameters of reproductive, carcass, and meat quality traits in Polled Nellore cattle

Considering the economic and commercial efficiency of the beef production chain, the yield and quality of the meat produced must also be included in breeding programs. For the Nellore breed, including the polled herd, these aspects have not been much studied. The aim of this study was to estimate genetic parameters for scrotal circumference adjusted to 365 (SC365) and 450 (SC450) days of age, age at first calving (AFC), accumulated productivity (AP), stayability (STAY), longissimus muscle area (LMA), thickness of subcutaneous fat over the 12th-13th ribs (BF), thickness of subcutaneous fat over the rump (RF), and shear force measured by Warner-Bratzler shear force (WBSF) of polled Nellore cattle. Bayesian analyses were performed by adopting a linear animal model, whereas STAY analyses used the linear threshold model. Heritability estimates were 0.31 (SC365), 0.37 (SC450), 0.16 (AFC), 0.25 (AP), 0.16 (STAY), 0.30 (LMA), 0.13 (BF), 0.24 (RF), and 0.15 (WBSF), indicating moderate response to selection. Genetic and residual correlations between SC365 and SC450 were high (0.91 and 0.74, respectively), as well as the genetic correlations of AP with SC365, SC450, AFC, and STAY (0.61, 0.62, - 0.69, and 0.83, respectively). Genetic and residual correlations of WBSF with reproductive and carcass characteristics exhibited high standard deviations, however favorable. Based on the results, it is expected that in the medium term, animals with greater sexual precocity will also have greater accumulated productivity and longer permanence of females in the herd, along with superior carcass traits. However, due to the low heritabilities and small genetic associations with reproductive traits, fat thickness characteristics (BF and RF) will still require direct selection.

Diagnosis and treatment of HEp-2 cells contaminated with mycoplasma

Contamination of primary and cell cultures by mycoplasmas is one of the main economic and biological pitfalls in basic research, diagnosis and manufacture of biotechnological products. It is a common issue which may be difficult to conduct surveillance on. Mycoplasma presence may affect several physiological parameters of the cell, besides being considered an important source of inaccurate and/or non-reproducible scientific results. Each cell type presents characteristical symptoms, mainly morphological, that indicate a contamination by mycoplasma. HEp-2 cells originate from carcinoma of the larynx and are, therefore, part of the respiratory tract, which is one of mycoplasma habitats. Despite the importance these cells in several biological research (evaluation of cell proliferation and migration, apoptosis, antiviral and antitumor compounds), the alterations induced by mycoplasma contamination in HEp-2 cells have not yet been described. Here, we describe the progressive morphological alterations in culture of HEp-2 cells infected with mycoplasma, as well as the-diagnosis of the infection and its treatment. Mycoplasma contamination described within this work led to cytoplasm elongation, cell-to-cell spacing, thin plasma membrane projections, cytoplasmic vacuoles, fusion with neighboring cells, and, finally, cell death. Contamination was detected by fluorescence imaging (DAPI) and PCR reactions. The cultures were treated with BM-Cyclin antibiotic to eliminate contamination. The data presented here will be of relevance to researchers whose investigations involve cell culture, especially respiratory and HEp-2 cells.

Brain-Sparing Sympathofacilitators Mitigate Obesity without Adverse Cardiovascular Effects

Anti-obesity drugs in the amphetamine (AMPH) class act in the brain to reduce appetite and increase locomotion. They are also characterized by adverse cardiovascular effects with origin that, despite absence of any in vivo evidence, is attributed to a direct sympathomimetic action in the heart. Here, we show that the cardiac side effects of AMPH originate from the brain and can be circumvented by PEGylation (PEGyAMPH) to exclude its central action. PEGyAMPH does not enter the brain and facilitates SNS activity via theβ₂-adrenoceptor, protecting mice against obesity by increasing lipolysis and thermogenesis, coupled to higher heat dissipation, which acts as an energy sink to increase energy expenditure without altering food intake or locomotor activity. Thus, we provide proof-of-principle for a novel class of exclusively peripheral anti-obesity sympathofacilitators that are devoid of any cardiovascular and brain-related side effects.

The influence of the morphological characteristics of nanoporous anodic aluminium oxide (AAO) structures on capacitive touch sensor performance: a biological application

This work is devoted to the study of the influence of different anodic aluminium oxide (AAO) morphologies on the sensitivity and performance of an AAO-based capacitive touch sensor. The AAO structures were fabricated in a cylindrical homemade anodization cell made from a solid polycarbonate billet via a lathe machining process. The AAO morphologies were obtained from the anodization of Al foil by using three different types of electrolyte (sulphuric acid, oxalic acid and phosphoric acid) and their morphologies are reported and compared using scanning electron microscopy (SEM) micrographs and current–time characteristic curves. The sensors were fabricated by integrating the AAO structure with a nanotextured gold thin film deposited over the AAO layer by thermal evaporation, thus realizing a type of metal/insulator/metal parallel-plate capacitance sensor. It is demonstrated that AAO morphologies have influence on the performance of the AAO-based capacitive touch sensors. The variation of the capacitance of the sensors is investigated in this work for the AAO structures produced from anodization in an attempt to select anodizing conditions for a biological application aiming to detect small microorganisms such as bacterial colonies of Escherichia coli.

This work is devoted to the study of the influence of different anodic aluminium oxide (AAO) morphologies on the sensitivity and performance of an AAO-based capacitive touch sensor.

Avaliação do Condicionamento de Pinos de Fibra de Vidro com Aminopropiltrietoxisilano (APTES): Estudo Piloto

Este estudo avaliou o tratamento de superfície de pinos de fibra de vidro (PFV) com APTES na resistência de união (RU) à dentina radicular. Os PFV foram cimentados em 12 raízes de dentes bovinos, previamente selecionadas, as quais foram embutidas e distribuídas em 4 grupos experimentais (n3), de acordo com o tratamento de superfície do PFV: G1 metacriloxipropiltrietoxisilano (MPS)/1min G2 H2O2 24%/1min + MPS 1min G3 APTES/1min e G4 APTES/5min. Após embutimento das raízes, hibridização das paredes dos condutos e fixação dos PFV com cimento dual, os espécimes foram seccionados em discos de acordo com o terço radicular [cervical (C), médio (M) e apical (A)] e submetidos ao ensaio de push-out, para análise da RU. Os dados colhidos, após verificação da homocedasticidade amostral, foram submetidos à ANOVA de 2 fatores (a5%). Tanto para os 2 fatores quanto para   a interação, não foram observadas diferenças estatisticamente significantes (p > 0,05). Os valores de RU (MPa) foram: Para o tratamento de superfície: G1 (2,45) G2 (3,66) G3 (5,45) G4 (5,00). Para o terço radicular: C (4,37) M (3,80) A (4,26). Concluiu-se que, o tratamento de superfície de PFV com APTE não influenciou os resultados de RU, sendo semelhante aos demais protocolos estudados. As falhas foram predominantemente adesivas na interface entre cimento/dentina.Palavras-chave: Resistência de união. Pinos de Fibra de Vidro. Tratamento de Superfície.

Chloroplast diversity of Casearia grandiflora in the Cerrado of Piauí State

Casearia grandiflora (Salicaceae) is a typical Cerrado species adapted to disturbed environments, making it useful for restoration projects. Knowledge of genetic diversity is important for establishing conservation strategies for this species. This study aimed to compare chloroplast haplotype diversity and structure of C. grandiflora, under the assumption that protected areas hold greater genetic diversity than disturbed areas. The populations studied are from Parque Nacional de Sete Cidades Conservation Unit and from the surroundings of the city of Cocal de Telha, both located in the State of Piauí. Molecular analyses were performed with seven chloroplast microsatellite loci. The number of private haplotypes and haplotype diversity were higher in the conservation unit, which reinforces the importance of these areas in maintaining biodiversity. Analysis of molecular variance showed that most of the genetic variation is found within populations, with a moderate divergence between them (F_ST = 0.14). The Bayesian analysis and discriminant analysis of principal components suggested that populations are not structured, revealing that a set of individuals from Parque Nacional de Sete Cidades were more divergent within populations than between them. Since literature has little information on C. grandiflora, the results of this study provide important contribution to a better understanding of the specie's genetic diversity.

Special challenges in the conservation of fishes and aquatic environments of South America

In South America, the conservation of natural resources, particularly in relation to water and aquatic fauna, is an often-discussed issue. Unfortunately, there is still a large gap between thoughts and action. Scientists from different countries of the continent have however, produced a significant body of literature that should finally become the basis of emerging managerial models.

Changes in the composition of ichthyoplankton assemblage and plastic debris in mangrove creeks relative to moon phases

Lunar influence on the distribution of fish larvae, zooplankton and plastic debris in mangrove creeks of the Goiana Estuary, Brazil, was studied over a lunar cycle. Cetengraulis edentulus, Anchovia clupeoides and Rhinosardinia bahiensis were the most abundant fish larvae (56·6%), independent of the moon phase. The full moon had a positive influence on the abundance of Gobionellus oceanicus, Cynoscion acoupa and Atherinella brasiliensis, and the new moon on Ulaema lefroyi. The full and new moons also influenced the number of zoeae and megalopae of Ucides cordatus, protozoeae and larvae of caridean shrimps, and the number of hard and soft plastic debris, both <5 and >5 mm. Micro and macroplastics were present in samples from all 12 creeks studied, at densities similar to the third most abundant taxon, R. bahiensis. Cetengraulis edentulus and R. bahiensis showed a strong positive correlation with the last quarter moon, when there was less zooplankton available in the creeks and higher abundance of microplastic threads. Anchovia clupeoides, Diapterus rhombeus, U. lefroyi and hard microplastics were positively associated with different moon phases, when calanoid copepods, Caridean larvae and zoeae of U. cordatus were highly available in the creeks. Cynoscion acoupa, G. oceanicus and A. brasiliensis were strongly associated with the full moon, when protozoeae of caridean shrimps and megalopae of U. cordatus were also highly available, as were hard and soft macroplastics, paint chips (<5 mm) and soft microplastics. The results reinforce the role of mangrove creeks as nursery habitats. The moon phases influenced the distribution of fish larvae species, zooplankton and plastic debris by changing their compositions and abundances in the mangrove creeks of the Goiana Estuary when under the influence of different tidal current regimes.

Seasonal and spatial ontogenetic movements of Gerreidae in a Brazilian tropical estuarine ecocline and its application for nursery habitat conservation

The density and biomass of different ontogenetic phases (juvenile, sub-adult and adult) of the two most important sympatric Gerreidae species in the Goiana Estuary, north-east Brazil, are described in order to determine the patterns of estuarine habitat use and to identify nursery grounds. Eugerres brasilianus and Eucinostomus melanopterus were the most abundant gerreids in the main channel and adjacent estuarine beach habitats. Eugerres brasilianus is abundant in the main channel, whereas E. melanopterus is most common in the beach habitats. Significant interaction in density and biomass of juvenile and sub-adult size classes of E. brasilianus was found between season and area. In addition, E. brasilianus adults and E. melanopterus sub-adults differed significantly in density and biomass between areas of the estuary. Both the upper estuary, during the late dry season, and the middle estuary, during the early rainy season, functioned as nursery habitats for E. brasilianus. During the early rainy season and dry season, the beaches were a nursery for the E. melanopterus. The concentration of these ontogenetic phases was mainly related to the dissolved oxygen and salinity gradients of the estuary, which drive not only gerreid movement between estuarine habitats but also moves the habitats. This study reinforces the importance of conserving the habitats of the Goiana Estuary so that species such as gerreids can complete their life cycle in the face of pressure from anthropogenic activities, such as mangrove forest deforestation, overfishing, fish contamination by plastic ingestion and domestic effluent disposal.

Effect of LED-LCU light irradiance distribution on mechanical properties of resin based materials

The objective of this study is to analyze the light power distribution along the tip end of the light guide of three LED-LCUs (Light Curing Units) and to evaluate its effect on the mechanical properties of a polymer based dental composite. Firstly, the light power distribution over the whole area of LED-LCU light guide surface was analyzed by three methods: visual projection observation, spectral measurement and optical spectral analysis (OSA). The light power distribution and the total irradiance were different for the three LEDs used, but the wavelength was within the camphorquinone absorption spectrum. The use of a blank sheet was quite on hand to make a qualitative analysis of a beam, and it is costless. Secondly, specimens of a hybrid composite with approximately 8mm diameter and 2mm thickness were produced and polymerized by 20s exposition time to each LED-LCU. Thirdly, the elastic modulus (E) and hardness (HV) were measured throughout the irradiated area by instrumented micro-indentation test (IIT), allowing to correlate localized power and mechanical properties. Both E and HV showed to be very sensitive to local power and wavelength dependent, but they followed the beam power profile. It was also shown that the mechanical properties could be directly correlated to the curing process. Very steep differences in mechanical properties over very short distances may impair the material performance, since residual stresses can easily be built over it.

Feeding ecology and seasonal diet overlap between Stellifer brasiliensis and Stellifer stellifer in a tropical estuarine ecocline

Seasonal freshwater discharge was important for defining habitat utilization by different ontogenetic phases of Stellifer brasiliensis and Stellifer stellifer along the estuarine ecocline. The middle estuary was important as a nursery and feeding ground for young-of-the-year, and a feeding ground for sub-adults and adults of both species. These species are zoobenthivorous, but during their life cycle and between different habitats and seasons, their trophic guild can change to opportunist and zooplanktivore. During the late rainy season in the lower estuary, all phases of both species, except juveniles of S. brasiliensis and adults of S. stellifer, showed a niche overlap indicating similarity in prey utilization. The diet composition was qualitatively similar, showing an evident niche overlap of intra and interspecific competition among the Stellifer spp. Although the niches of these species appeared to significantly overlap, some resource partitioning patterns were apparent. The niche overlap was significantly reduced due to the seasonal difference in habitat use and prey consumption along the ecocline of the estuary by different ontogenetic phases. The ingestion of blue nylon fragments by both species was observed and quantified.

Trophic niche and habitat shifts of sympatric Gerreidae

The diet and mouth growth rates of three Gerreidae species (Eugerres brasilianus, Eucinostomus melanopterus and Diapterus rhombeus) were assessed at different ontogenetic phases (juveniles, sub-adults and adults) in order to detect allometric growth, and whether they are related to habitat and seasonal changes in the Goiana Estuary, north-east Brazil. The importance of each prey for each ontogenetic phase was described using the index of relative importance. The three species showed seasonal ontogenetic shifts in diet and allometric growth of mouth morphology. They also had an exclusively zoobenthic diet, comprising mainly Polychaeta, Copepoda, Ostracoda, Gastropoda and Bivalvia. Mouth development showed a possible influence on diet changes for E. melanopterus. Significant interactions (P < 0·01) were detected among seasons, areas and ontogenetic phases for the most important prey for E. brasilianus and E. melanopterus. Diet overlaps are evidence of intra and interspecific competition among gerreids for specific prey. A conceptual model of the competition and seasonal diet shifts among ontogenetic phases of gerreids is given. The sediment ingested due to the feeding mechanisms of Gerreidae species could also partially explain the ingestion of synthetic items observed for all ontogenetic phases, which indicates one of a myriad effects of human activities (e.g. artisanal fishery) in this estuary.

Grazing behaviour of a non-herbivorous characin: revisiting plasticity

Feeding behaviour and diet of Bryconamericus microcephalus differed between canopy conditions. At the open canopy site, a behavioural modification, grazing on algae, was observed. This was also reflected in gut content analysis and suggests behavioural plasticity in response to resource availability.

Distribution patterns of microplastics within the plankton of a tropical estuary

The Goiana Estuary was studied regarding the seasonal and spatial variations of microplastics (<5mm) and their quantification relative to the zooplankton. The total density (n 100 m(-3)) of microplastics represented half of the total fish larvae density and was comparable to fish eggs density. Soft, hard plastics, threads and paint chips were found in the samples (n=216). Their origins are probably the river basin, the sea and fisheries (including the lobster fleet). In some occasions, the amount of microplastics surpassed that of Ichthyoplankton. The highest amount of microplastics was observed during the late rainy season, when the environment is under influence of the highest river flow, which induces the runoff of plastic fragments to the lower estuary. The density of microplastics in the water column will determine their bioavailability to planktivorous organisms, and then to larger predators, possibly promoting the transfer of microplastic between trophic levels. These findings are important for better informing researchers in future works and as basic information for managerial actions.

Resonance energy transfer in self-organized organic/inorganic dendrite structures

Hybrid materials formed by semiconductor quantum dots and J-aggregates of cyanine dyes provide a unique combination of enhanced absorption in inorganic constituents with large oscillator strength and extremely narrow exciton bands of the organic component. The optical properties of dendrite structures with fractal dimension 1.7-1.8, formed from J-aggregates integrated with CdTe quantum dots (QDs), have been investigated by photoluminescence spectroscopy and fluorescence lifetime imaging microscopy. Our results demonstrate that (i) J-aggregates are coupled to QDs by Förster-type resonant energy transfer and (ii) there are energy fluxes from the periphery to the centre of the structure, where the QD density is higher than in the periphery of the dendrite. Such an anisotropic energy transport can be only observed when dendrites are formed from QDs integrated with J-aggregates. These QD/J-aggregate hybrid systems can have applications in light harvesting systems and optical sensors with extended absorption spectra.

Early development of marine catfishes (Ariidae): from mouth brooding to the release of juveniles in nursery habitats

The development and allometric growth patterns of the ariid catfishes Cathorops spixii and Cathorops agassizii were studied from neurula embryos to juveniles. The ontogenetic sequence revealed that prior to hatching, embryos of both species are well developed, and their axial and appendicular skeletons are well ossified. Embryos of both species grow slowly longitudinally, but positively allometric growth (growth coefficient, β1 > 1) was observed in head width and eye diameter. It is hypothesized that these growth patterns might be related to functional priorities for the development of sensory organs, such as the inner ears (otoliths), the Weberian apparatus, eyes and nostrils, during the embryonic period. The first appearance of vertebrae and otoliths, as well as the ossification of otoliths and the Weberian apparatus, occur earlier in embryos of C. agassizii than in embryos of C. spixii. After hatching, mouth-brooded free embryos of both species grow isometrically. Negatively allometric growth was observed in head width and eye diameter during the yolk-sac period, which is expected given that the sensory organs are already formed. Free embryos of C. agassizii are distinguishable from those of C. spixii by their larger eyes, longer snouts, longer heads and heavier yolk sacs. The end of the yolk-sac period is characterized by a direct change from free embryo to juvenile, without a true larval period. The juveniles of the two species can also be distinguished from each other by the larger eyes of C. agassizii compared with C. spixii, as in adult fishes.

The interaction rainfall vs. weight as determinant of total mercury concentration in fish from a tropical estuary

Mercury loads in tropical estuaries are largely controlled by the rainfall regime that may cause biodilution due to increased amounts of organic matter (both live and non-living) in the system. Top predators, as Trichiurus lepturus, reflect the changing mercury bioavailability situations in their muscle tissues. In this work two variables [fish weight (g) and monthly total rainfall (mm)] are presented as being important predictors of total mercury concentration (T-Hg) in fish muscle. These important explanatory variables were identified by a Weibull Regression model, which best fit the dataset. A predictive model using readily available variables as rainfall is important, and can be applied for human and ecological health assessments and decisions. The main contribution will be to further protect vulnerable groups as pregnant women and children. Nature conservation directives could also improve by considering monitoring sample designs that include this hypothesis, helping to establish complete and detailed mercury contamination scenarios.

Influence of moon phase on fish assemblages in estuarine mangrove tidal creeks

Significant differences in the composition of fish assemblages during different moon phases were detected in mangrove tidal creeks of the Goiana Estuary. The numbers of Zabaleta anchovy Anchovia clupeoides, Tarpon snook Centropomus pectinatus and Guavina Guavina guavina as well as at least 15 other species showed significant changes according to moon phase and were higher in terms of individuals (32%) and mass (34%) during the new moon.

Fish and aquatic habitat conservation in South America: a continental overview with emphasis on neotropical systems

Fish conservation in South America is a pressing issue. The biodiversity of fishes, just as with all other groups of plants and animals, is far from fully known. Continuing habitat loss may result in biodiversity losses before full species diversity is known. In this review, the main river basins of South America (Magdalena, Orinoco, Amazon and Paraná-La Plata system), together with key aquatic habitats (mangrove-fringed estuaries of the tropical humid, tropical semi-arid and subtropical regions) are analysed in terms of their characteristics and main concerns. Habitat loss was the main concern identified for all South American ecosystems. It may be caused by damming of rivers, deforestation, water pollution, mining, poor agricultural practice or inadequate management practice. Habitat loss has a direct consequence, which is a decrease in the availability of living resources, a serious social and economic issue, especially for South American nations which are all developing countries. The introduction of exotic species and overfishing were also identified as widespread across the continent and its main freshwater, coastal and marine ecosystems. Finally, suggestions are made to find ways to overcome these problems. The main suggestion is a change of paradigm and a new design for conservation actions, starting with integrated research and aiming at the co-ordinated and harmonized management of the main transboundary waters of the continent. The actions would be focused on habitat conservation and social rescue of the less well-off populations of indigenous and non-indigenous peoples. Energy and freshwater demands will also have to be rescaled in order to control habitat loss.

Movement patterns of catfishes (Ariidae) in a tropical semi-arid estuary

From December 2005 to November 2006, 216 samples were taken from the main channel of the Goiana Estuary, representing a total sampled area of 23 ha. Ariidae species were the most abundant in density (1600 individuals ha(-1), 53%) and biomass (18,813 g ha(-1), 63%). Cathorops spixii was the most abundant in density (1340 individuals ha(-1)) and biomass (14,203 g ha(-1)). The variables: number of species, total density and biomass, showed significant interactions between the factors of areas and seasons (P < 0.01). The highest total density (7394 individuals ha(-1)) and biomass (70,292 g ha(-1)) occurred in the middle and upper estuaries, respectively, during the early-rainy season. The density of C. spixii differed significantly between areas and seasons (P < 0.01), while Cathorops agassizii differed significantly only between seasons (P < 0.01). The biomass differed significantly for the species C. spixii, C. agassizii and Sciades herzbergii between seasons, and C. spixii and C. agassizii between areas. Also, the density and biomass of C. spixii and C. agassizii showed interaction between areas and seasons. Only the biomass of S. herzbergii showed interaction between areas and seasons (P < 0.01). This indicates that seasonal variations influenced the distribution of Ariidae species in the different areas of the Goiana Estuary. Moreover, canonical correspondence analysis highlighted a strongly significant correlation (P < 0.01) between the seasonal variations of the environmental gradients (salinity and water temperature) and distribution of catfishes. The management and conservation of estuaries should take into account the life cycle of these species in different estuarine areas and hydrological seasons.

Long-term loss of color vision after exposure to mercury vapor

We evaluated the color vision of 24 subjects (41.6 +/- 6.5 years; 6 females) who worked in fluorescent lamp industries. They had been occupationally exposed to mercury vapor (10.6 +/- 5.2 years) and had been away from the source of exposure for 6.4 +/- 4.04 years. Mean urinary concentration of mercury was 40.6 +/- 36.4 microg/g creatinine during or up to 1 year after exposure and 2.71 +/- 1.19 microg/g creatinine at the time of color vision testing or up to 1 year thereafter. All patients were diagnosed with chronic mercury intoxication, characterized by clinical symptoms and neuropsychological alterations. A control group (N = 36, 48.6 +/- 11.9 years, 10 females, 1.5 +/- 0.47 microg mercury/g creatinine) was subjected to the same tests. Inclusion criteria for both groups were Snellen VA 20/30 or better and absence of known ophthalmologic pathologies. Color discrimination was assessed with the Farnsworth D-15 test (D-15) and with the Lanthony D-15d test (D-15d). Significant differences were found between the two eyes of the patients (P < 0.001) in both tests. Results for the worst eye were also different from controls for both tests: P = 0.014 for D-15 and P < 0.001 for D-15d. As shown in previous studies, the D-15d proved to be more sensitive than the D-15 for the screening and diagnosis of the color discrimination losses. Since color discrimination losses were still present many years after the end of exposure, they may be considered to be irreversible, at least under the conditions of the present study.

Serologic immunoreactivity to Neospora caninum antigens in dogs determined by indirect immunofluorescence, western blotting and dot-ELISA

Neospora caninum, is a coccidian protozoan known as a major cause of bovine abortion and canine neuropathies. The aim of the present study was to develop a reliable and quick test to detect antibodies to N. caninum in dog sera. Sixty-five serum samples from dogs, including 35 positive and 30 negative for N. caninum antibodies were used for standardization of the test. In parallel, immunoreactivity of the sera to Toxoplasma gondii antigens was investigated using a passive agglutination test. A dot-ELISA test, using soluble extract of N. caninum tachyzoites on nitrocellulose ester membranes, was developed and standardized. SDS-PAGE and complementary analysis of reactivity by Western blotting were used for the characterization of the immunoreactive fractions of all tested sera. The sensitivity and specificity of the dot-ELISA were 94 and 73%, respectively, compared to IFAT at a cut-off of 1:50, and 87 and 100% compared to IFAT at a cut-off of 1:25. Among the sera that tested positively for both IFAT and dot-ELISA, only 8.6% were reactive to T. gondii. The most immunoreactive fractions in Western blots were the 14-, 33-, 42- and 55 kDa bands, with percentages of 42, 60, 42 and 37%, respectively. The 60 kDa band showed a non-specific reaction in 43% of neosporosis-negative animals by both dot-ELISA and IFAT. These results indicate that the dot-ELISA using N. caninum antigen present good sensitivity and specificity, and might be used as a screening test to detect antibodies to N. caninum in dogs.

Colour vision and contrast sensitivity losses of mercury intoxicated industry workers in Brazil

We evaluated vision loss in workers from fluorescent lamp industries (n=39) who had retired due to intoxication with mercury vapour and had been away from the work situation for several years (mean=6.32 years). An age-matched control group was submitted to the same tests for comparison. The luminance contrast sensitivity (CSF) was measured psychophysically and with the sweep visual evoked potential (sVEP) method. Chromatic red-green and blue-yellow CSFs were measured psychophysically. Colour discrimination was assessed with the Farnsworth-Munsell 100-hue test, Lanthony D-15d test and Cambridge Colour Vision Test. Patient data showed significantly lower scores in all colour tests compared to controls (p<.001). The behavioural luminance CSF of the patients was lower than that of controls (p<.001 at all frequencies tested). This result was confirmed by the electrophysiologically measured sweep VEP luminance CSF except at the highest frequencies-a difference that might be related to stimulus differences in the two situations. Chromatic CSFs were also statistically significantly lower for the patients than for the controls, for both chromatic equiluminant stimuli: red-green (p<.005) and blue-yellow (p<.04 for all frequencies, except 2 cycles per degree (cpd), the highest spatial frequency tested) spatial gratings. We conclude that exposure to elemental mercury vapour is associated with profound and lasting losses in achromatic and chromatic visual functions, affecting the magno-, parvo- and koniocellular visual pathways.

Contrast sensitivity threshold measured by sweep-visual evoked potential in term and preterm infants at 3 and 10 months of age

Although healthy preterm infants frequently seem to be more attentive to visual stimuli and to fix on them longer than full-term infants, no difference in visual acuity has been reported compared to term infants. We evaluated the contrast sensitivity (CS) function of term (N = 5) and healthy preterm (N = 11) infants at 3 and 10 months of life using sweep-visual evoked potentials. Two spatial frequencies were studied: low (0.2 cycles per degrees, cpd) and medium (4.0 cpd). The mean contrast sensitivity (expressed in percentage of contrast) of the preterm infants at 3 months was 55.4 for the low spatial frequency (0.2 cpd) and 43.4 for the medium spatial frequency (4.0 cpd). At 10 months the low spatial CS was 52.7 and the medium spatial CS was 9.9. The results for the term infants at 3 months were 55.1 for the low spatial frequency and 34.5 for the medium spatial frequency. At 10 months the equivalent values were 54.3 and 14.4, respectively. No difference was found using the Mann-Whitney rank sum T-test between term and preterm infants for the low frequency at 3 or 10 months or for the medium spatial frequency at 3 or 10 months. The development of CS for the medium spatial frequency was equally fast for term and preterm infants. As also observed for visual acuity, CS was equivalent among term and preterm infants, suggesting that visual experience does not modify the development of the primary visual pathway. An earlier development of synapses in higher cortical visual areas of preterm infants could explain the better use of visual information observed behaviorally in these infants.

[Multiple sclerosis, spinal cord ependymoma and intracranial meningioma: case report]

We report the association a multiple sclerosis (MS), spinal cord tumour and intracranial tumor in a 63 years-old female patient with a 10 years history of relapsing/remitting MS. Symptoms usually remitted in response to costicosteroid therapy. In 1997 the patient presented with paraparesis and paresis of right arm which did not respond to corticotherapy. A spinal RMI revealed in the cervical spinal an intra spinal cord tumour, further diagnosed as ependymoma, and a parietal region meningioma. We call attention to this rare association of central nervous system tumour and MS, enphasizing the need for investigation of new and uncommon symptoms during the evolution of MS.

Calculated Infrared, Raman, and Rayleigh Properties of the CO(3) Molecule

Properties associated with the infrared, Rayleigh, and Raman spectra of the CO(3) molecule are calculated by the Hartree-Fock and Møller-Plesset perturbation theory methods. Vibrational frequencies and infrared activities are found to be in agreement with the experiment and previous calculations. The values obtained for the Raman spectrum show a very sensitive dependence to the treatment of electron correlation. The OCO wag normal mode, unobserved in the IR experiment, is predicted to have a very small Raman scattering activity. Copyright 2000 Academic Press.

Effect of ventilation systems on prevalence of symptoms associated with "sick buildings" in Brazilian commercial establishments

In this questionnaire study, the authors compared the prevalence of certain symptoms and signs associated with Sick Building Syndrome and perceptions relative to environmental discomfort of employees in a central-air-conditioned dropping center and in natural-ventilation commercial shops located on the streets of Niteroi, Rio de Janeiro, Brazil. There was a statistically significant higher prevalence of symptoms (e.g., water and itching of eyes, sore throat, nose irritation, difficulty breathing, skin irritation, sneezing) that were characteristic of Sick Building Syndrome in the air-conditioned building than in the naturally ventilated stores. The results indicated that there exists a continuing need for further research in Brazilian work environments.

The Bambuí health and ageing study (BHAS): methodological approach and preliminary results of a population-based cohort study of the elderly in Brazil

OBJECTIVE

A cohort study has been designed to identify predictors of adverse health events in the elderly. The methodology of the study and preliminary descriptive results are presented.

METHODS

The study population comprises all residents of Bambuí (Minas Gerais, Brazil), aged 60 or more years (n=1.742). From these, 92.2% were interviewed and 85.9% underwent clinical examination, consisting of haematological and biochemical tests, serology for Trypanosoma cruzi, anthropometric and blood pressure measures and electrocardiogram. Aliquots of serum, plasma and DNA were stored for future investigations. The baseline interview included sociodemographic characteristics, self-referred health condition and history of selected diseases, medication use, health service use, source of medical care, physical activities, smoking, drinking and eating habits, reproductive history, physical functioning, life events, social support and mental health. Individuals are being followed up annually.

RESULTS

The following characteristics predominated among participants: women (60,0%), married (48.9%) or widowed (35.4%), people living in households with up to 2 residents (73.8%), heads of family (76.7%), people with monthly income between 1.00 and 2.99 Brazilian minimum wages (62.0%) and people with up to 4 years of schooling (89.1%). The median age was 68 years. Among the cohort members, only 1.7% were lost in the first follow-up.

CONCLUSIONS

In general, the characteristics of the study population were very similar to those from other epidemiological studies of the elderly based on large Brazilian cities. The small number of losses to follow-up indicates that the choice of Bambuí was adequate, assuring the feasibility of a long term cohort study.

[Death of elderly patients in the Santa Genoveva Clinic in Rio de Janeiro: excess mortality that the public health system could have prevented]

From January to May 1996, 156 inpatients died in a clinic for elderly people in Rio de Janeiro, Brazil. The highest mortality rate was observed in May: 143/1,000 inpatients. As a result, the clinic was closed by the Ministry of Health. This study investigated whether the excessive number of deaths observed in the clinic in early 1996 was unexpected or reflected prevailing conditions. The investigation used the Public Health System database (SIH-SUS). The study period was 01/1993 to 05/1996. The investigation was based on: 1) a time-series analysis of the number of deaths and crude mortality rates and 2) comparison of the mortality rates observed in that clinic with those calculated for 15 area hospitals, defined as the reference rates. Risk of death in the clinic was higher than expected in 28 of the 41 months considered in the study. Highest risks were observed in January 1993 (RRcrude = 2.23; 95% CI 1.56-3. 14) and May 1996 (RRadjusted = 2.73; 95% CI 1.88-3.95). The high mortality rates observed in the clinic in 1996 were already present in 1993. Thus, adequate use of the SIH-SUS could have anticipated and avoided the excess mortality identified in early 1996.

Emergency physician's diagnosis of stroke subtype. An accuracy study

OBJECTIVE

To evaluate the accuracy of clinical unstructured and structured diagnosis of acute stroke subtypes--cerebral haemorrhage (CH), cerebral infarction (CI), subarachnoid haemorrhage (SAH).

METHODS

Sixty consecutive patients with acute stroke admitted to the Emergency Ward of a Brazilian University Hospital were examined by emergency physicians and computerised tomography (CT). We also compared it (physician's unstructured diagnosis) to two published clinical scoring systems (structured diagnosis--Guy's Hospital and Siriraj Hospital) applied to three other populations--regarding the operational characteristics of the tests.

RESULTS

In our personal data, among 9 variables that could discriminate CH and CI, three have statistically significant difference (p < 0.05): headache (p = 0.0002) and vomiting (p = 0.02) occurred more frequently in CH patients, but previous stroke in those with CI (p = 0.04). Unstructured diagnosis proved valid for SAH, with a +LHR = 39.7; and to a smaller degree for CI (-LHR = 0.1). However, it exhibited low sensitivity for the diagnosis of CH. Structured tests (Guy's Hospital and Siriraj Hospital) also failed to confidently diagnose stroke subtypes, especially CH.

CONCLUSIONS

Both clinical diagnosis (made by emergency physicians) and the available diagnostic tests fail to confidently discriminate CH and CI.

[Knowledge and practices regarding stroke at a university hospital: Part 2. Medical education in the new era of treatment of cerebral infarction]

BACKGROUND AND PURPOSE

This study was undertaken to evaluate professionals working at a University Hospital as to their knowledge and attitudes towards stroke.

METHODS

Individuals working in the hospital were divided in two groups, Health care workers (HCW) and non-Health care workers (NHCW), and further subdivided according to level of schooling, resulting in seven strata. A closed questionnaire addressing epidemiology, risk factors, pathophysiology, typical symptoms, treatment, clinical course and personal attitudes towards smoking and blood pressure control, was applied to a random sample of each stratum (total n = 309). The physicians group included 48 individuals. Kruskal-Wallis test for multiple comparisons of non-parametric data was used. Special attention was given to the wrong answers.

RESULTS

Physicians correctly answered 92.6% of the questions. Their performance was superior to that of all other groups in all subgroups of questions. However, a large number of errors was found in questions addressing mortality and hospital mortality following stroke and the intimate relation between coronary and cerebral atherosclerosis. Treatment options in cerebral infarction are also poorly recognised.

CONCLUSIONS

Although physicians general knowledge about stroke is good, they frequently do not perceive it as a critical disease requiring urgent hospital evaluation and care. The importance of a thorough cardiac evaluation following stroke and of the intimate relation between cardiac and cerebral ischemic disease is also unclear to this group. More hours of stroke teaching and practical training in stroke could possibly fill these gaps.

[Knowledge and practices regarding stroke at a university hospital: Part 1. Education of the nursing staff: priorities for the treatment of cerebral infarction]

BACKGROUND AND PURPOSE

This study was undertaken to evaluate professionals working at a university hospital as to their knowledge and attitudes towards stroke.

METHODS

Individuals working in the hospital were divided in two groups, health care workers (HCW) and non-health care workers (NHCW), and further subdivided according to level of schooling, resulting in seven strata. A closed questionnaire addressing epidemiology, risk factors, pathophysiology, typical symptoms, treatment, clinical course and personal attitudes towards smoking and blood pressure control, was applied to a random sample of each stratum (total n = 309). Kruskal-Wallis test for multiple comparisons of non-parametric data was used.

RESULTS

Significant differences between the seven groups were found. Knowledge was strongly associated with being a HCW and with level of formal education (p < 0.001), even after excluding physicians from the analysis (p < 0.001). In NHCW groups, knowledge was not associated with level of education (p = 0.421). In these groups, personal fear of suffering a stroke was the only variable predictive of knowledge. Smoking and poor monitoring of blood pressure levels were also more common in strata with the lowest levels of education and among NHCW.

CONCLUSION

Poor knowledge and wrong attitudes towards stroke are frequent among individuals working in a Brazilian university hospital. Although these results are not necessarily applicable to the general population, they will certainly be useful for the development of educational programs on stroke.

[A hierarchical model for analysis of socio-economic variables and water contact patterns associated with the hepatosplenic form of schistosomiasis]

A study of factors associated with the hepatosplenic clinical form of schistosomiasis was carried out in an endemic area (Comercinho, Minas Gerais) where prevalence of Schistosoma mansoni infection was 70.4%. Of the 1,408 inhabitants aged two years and over, 1,162 (82.5%) participated in the study. Socio-demographic characteristics and reasons for water contacts of individuals with the hepatosplenic form (n = 73) were compared to those who did not present splenomegaly and eliminated (positive controls; n + 804) or did not eliminate S. mansoni eggs in stools (negative controls; n = 285). Multivariate analysis was performed, considering the existence of colinearity among socio-economic status of the family, running water in the household, and bathing in streams. The hepatosplenic form in children was strongly associated with occupation of the head of the family (manual workers) (OR = 11.4; 95% CI = 1.4 - 91.8), absence of running water in the household (OR = 7.7; 95% CI = 2.6 - 23.1), and bathing in streams (OR and 95% CI 7.6; 2.5-22.9 and 5.7; 1.3-25.5 for frequencies > weekly and <= weekly, respectively); bathing in streams, which implies intense contacts, was a consequence of the first two factors. Our results suggest that running water in the household can decrease morbidity from schistosomiasis because it reduces the need for intense contacts with streams.

System of optical noncontact microtopography

In this paper we describe a method of noncontact optical microtopography based on discrete triangulation. We show that a light beam with an oblique incidence on a surface can be used to assess the distance of the latter to a reference plane if the bright spot produced on the surface is imaged onto an array of detectors that tracks its lateral displacement. The light beam is swept over the surface so that large areas can be scanned. The authors have used their system with success for the topographic inspection of several surfaces, e.g., thin copper and silver films, polyethylene rough films and molds, graphite, machined metallic parts, and fabrics.

Relationships between titers of antibodies immunoreacting against glycolipid antigens from Mycobacterium leprae and M. tuberculosis, the Mitsuda and Mantoux reactions, and bacteriological loads: implications in the pathogenesis, epidemiology and serodiagnosis of leprosy and tuberculosis

Analysis of cell-mediated immunity [(CMI) as judged from the Mantoux, Fernandez, and Mitsuda reactions and the presence of granulomas in biopsy material] against humoral immunity (measurements of anti-PGL-I, PGL-Tb1, and SL-IV IgG and IgM antibody titers by ELISA) were performed in selected human populations. The investigations yielded data indicating that humoral (B-cell) responses preceded protective CMI in both tuberculosis and leprosy. The B-cell responses were unrelated to (unfavorable) cell-mediated delayed-type hypersensitivity (DTH). Notwithstanding the difficulty in inferring sequential events from studies in humans, it was shown that in humoral responses there was an initial rise of specific IgM immunoglobulins that switched afterward to IgG production during subclinical tuberculosis and leprosy infections. In patent tuberculosis disease the IgM-to-IgG switch was observed in the majority of patients; in patent leprosy disease the switch was impaired in the majority of patients. The clinical, immunological, and laboratory data indicated that the B-cell responses were suppressed as protective CMI was re-established in the patients during the protracted subclinical infection. According to the data, the diagnosis of subclinical tuberculosis and leprosy may be accomplished using ELISA. The yearly risk of tuberculosis in apparently healthy persons but with significant antibody titers was estimated at 44%; the yearly risk for leprosy has not yet been established. The clinical, epidemiologic, and diagnostic implications of these findings are discussed.

Exposure to acellular blood products and risk of HIV infection in hemophiliacs from Belo Horizonte, Brazil

Results of a HIV prevalence study conducted in hemophiliacs from Belo Horizonte, Brazil are presented. History of exposure to acellular blood components was determined for the five year period prior to entry in the study, which occurred during 1986 and 1987. Patients with coagulations disorders (hemophilia A = 132, hemophilia B = 16 and coagulation disorders other than hemophilia = 16) were transfused with liquid cryoprecipitate, locally produced, lyophilized cryoprecipitate, imported from São Paulo (Brazil) and factor VIII and IX, imported from Rio de Janeiro (Brazil), Europe, and United States. Thirty six (22%) tested HIV seropositive. The univariate and multivariate analysis (logistic model) demonstrated that the risk of HIV infection during the study period was associated with the total units of acellular blood components transfused. In addition, the proportional contribution of the individual components to the total acellular units transfused, namely a increase in factor VIII/IX and lyophilized cryoprecipitate proportions, were found to be associated with HIV seropositivity. This analysis suggest that not only the total amount of units was an important determinant of HIV infection, but that the risk was also associated with the specific component of blood transfused.