Estudo da patogenicidade para camundongos recém-nascidos de amostras de echovirus tipo 9 isoladas de casos de meningite durante um surto epidêmico no Rio de Janeiro

A patogenicidade do echovirus tipo 9 para camundongos recém-nascidos foi estudada, utilizando-se 12 amostras isoladas em cultura de células primárias de rim de macaco, a partir do liquor de crianças com meningite. Os animais inoculados com o fluido da primeira passagem em células desenvolveram paralisia flácida, após um período de 5 dias, com a morte ate o 8º dia. Os especimens originais de liquor não continham suficiente vírus para provocar sinais clínicos nos animais inoculados no período de 21 dias de observação. Ao exame histopatológico os animais doentes apresentaram miopatia necrotizante da musculatura paravertebral, língua e diafragma. Animais inoculados que não desenvolveram paralisia durante o período de observação apresentaram miosite discreta, sem que tenha sido encontrada necrose das fibras musculares.

Schistosoma mansoni: control of female fertility by the male

We have established an in vitro culture system for adult schistosomes that allows monitoring gene expression for up to more than ten days. Comparing female worms that are paired with those that have been separated, we find distinct differences, clearly documenting an influence of the male in female gene expression. In perfect coincidence with classical observations that were based on histological techniques, we find that the male particularly regulates gene expression in those tissues that are characterized by cell proliferation, e.g. the vitellaria. From these results, we hypothesize that the key target for the inductive signal that is transferred from the male to the female during pairing is the activation of a growth factor that stimulates mitotic proliferation.

Effects of Goyazensolide during in Vitro Cultivation of Schistosoma mansoni

Goyazensolide, a component extracted of Eremanthus goyazensis showed a significant inhibitory effect on egg-laying of Schistosoma mansoni during in vitro cultivation of this parasite. Motility of the worms was also reduced under treatment with goyazensolide and 90% of mortality was reached with concentrations up to 4mg/ml. It has found that separated worms were more susceptible than worms pairing during drug exposition and female alone was significantly more susceptible than male worm in the same conditions of in vitro cultivation. Natural products isolated from plants represent potential sources for the identification of structures useful for the design of alternative molecules to be used as new drug substances against several infectious diseases

Individual serological follow-up of patients with suspected or confirmed abdominal angiostrongyliasis

Abdominal angiostrongyliasis (AA) is a zoonotic nematode infection caused by Angiostrongylus costaricensis, with widespread occurrence in the Americas. Although the human infection may be highly prevalent, morbidity is low in Southern Brazil. Confirmed diagnosis is based on finding parasitic structures in pathological examination of biopsies or surgical resections. Serology stands as an important diagnostic tool in the less severe courses of the infection. Our objective is to describe the follow up of humoral reactivity every 2-4 weeks up to one year, in six individuals with confirmed (C) and ten suspected (S) AA. Antibody (IgG) detection was performed by ELISA and resulted in gradually declining curves of reactivity in nine subjects (56%) (4C + 5S), that were consistently negative in only three of them (2C + 1S) after 221, 121 and 298 days. Three individuals (2C + 1S) presented with low persistent reacitivity, other two (1C + 1S) were serologically negative from the beginning, but also presenting a declining tendency. The study shows indications that abdominal angiostrongyliasis is usually not a persistent infection: although serological negativation may take many months, IgG reactivity is usually declining along time and serum samples pairing may add valuable information to the diagnostic workout.

Chromosomal divergence and evolutionary inferences in Rhodniini based on the chromosomal location of ribosomal genes

In this study, we used fluorescence in situ hybridisation to determine the chromosomal location of 45S rDNA clusters in 10 species of the tribe Rhodniini (Hemiptera: Reduviidae: Triatominae). The results showed striking inter and intraspecific variability, with the location of the rDNA clusters restricted to sex chromosomes with two patterns: either on one (X chromosome) or both sex chromosomes (X and Y chromosomes). This variation occurs within a genus that has an unchanging diploid chromosome number (2n = 22, including 20 autosomes and 2 sex chromosomes) and a similar chromosome size and genomic DNA content, reflecting a genome dynamic not revealed by these chromosome traits. The rDNA variation in closely related species and the intraspecific polymorphism in Rhodnius ecuadoriensis suggested that the chromosomal position of rDNA clusters might be a useful marker to identify recently diverged species or populations. We discuss the ancestral position of ribosomal genes in the tribe Rhodniini and the possible mechanisms involved in the variation of the rDNA clusters, including the loss of rDNA loci on the Y chromosome, transposition and ectopic pairing. The last two processes involve chromosomal exchanges between both sex chromosomes, in contrast to the widely accepted idea that the achiasmatic sex chromosomes of Heteroptera do not interchange sequences.

Abnormal meiotic behavior in three species of Crotalaria

The objective of this work was to compare the meiotic behavior and pollen grain viability of three species of Crotalaria. Slides for meiotic analysis were prepared by the air-drying technique. Pollen grain viability was measured by three staining procedures (Alexander's solution, tetrazolium chloride and fluorescein diacetate) and in vitro germination in a sucrose solution. Eight bivalents were observed, confirming previous reports on populations from other regions of Brazil, as well as from other countries. All species showed abnormal meiotic behavior as follows: in Crotalaria micans, cytomixis and abnormal chromosome pairing in diakinesis; in C. spectabilis, abnormal chromosome pairing in diplotene; in C. zanzibarica, shrunk nuclei in leptotene and zygotene. Pollen grains of all three species show low viability, which may be associated with the irregularities of the meiotic behavior.

Preconcentration of copper from natural water samples using ligand-less in situ surfactant-based solid phase extraction prior to FAAS determination

In the present work, a simple and rapid ligand-less, in situ, surfactant-based solid phase extraction for the preconcentration of copper in water samples was developed. In this method, a cationic surfactant (n-dodecyltrimethylammonium bromide) was dissolved in an aqueous sample followed by the addition of an appropriate ion-pairing agent (ClO4-). Due to the interaction between the surfactant and ion-pairing agent, solid particles were formed and subsequently used for the adsorption of Cu(OH)2 and CuI. After centrifugation, the sediment was dissolved in 1.0 mL of 1 mol L-1 HNO3 in ethanol and aspirated directly into the flame atomic absorption spectrometer. In order to obtain the optimum conditions, several parameters affecting the performance of the LL-ISS-SPE, including the volumes of DTAB, KClO4, and KI, pH, and potentially interfering ions, were optimized. It was found that KI and phosphate buffer solution (pH = 9) could extract more than 95% of copper ions. The amount of copper ions in the water samples varied from 3.2 to 4.8 ng mL-1, with relative standard deviations of 98.5%-103%. The determination of copper in water samples was linear over a concentration range of 0.5-200.0 ng mL-1. The limit of detection (3Sb/m) was 0.1 ng mL-1 with an enrichment factor of 38.7. The accuracy of the developed method was verified by the determination of copper in two certified reference materials, producing satisfactory results.

Determination of Alkalinity and dissociation constants of high salinity waters: use of F5BC titration function

Measurements of parameters expressed in terms of carbonic species such as Alkalinity and Acidity of saline waters do not analyze the influence of external parameters to the titration such as Total free and associated Carbonic Species Concentration, activity coefficient, ion pairing formation and Residual Liquid Junction Potential in pH measurements. This paper shows the development of F5BC titration function based on the titrations developed by Gran (1952) for the carbonate system of natural waters. For practical use, samples of saline waters from Pocinhos reservoir in Paraiba were submitted to titration and linear regression analysis. Results showed that F5BC involves F1x and F2x Gran functions determination, respectively, for Alkalinity and Acidity calculations without knowing "a priori" the endpoint of the titration. F5BC also allows the determination of the First and Second Apparent Dissociation Constant of the carbonate system of saline and high ionic strength waters.

Gravidez e Diabetes Gestacional: uma combinação prejudicial à função sexual feminina?

OBJETIVO: Comparar a funcao sexual de gravidas adultas saudaveis a de mulheres com Diabetes Mellitus Gestacional (DMG) no terceiro trimestre da gravidez. MÉTODOS: Estudo transversal com dois grupos de gestantes em acompanhamento pre-natal. Foram criterios de inclusao: idade materna .20 anos, idade gestacional .28 semanas, relacionamento heterossexual com o mesmo parceiro ha pelo menos 6 meses e ser alfabetizada. Os criterios de exclusao foram: presenca de intercorrencias clinicas e/ou obstetricas que contraindicassem atividade sexual; hipertensao arterial controlada por medicamentos; gravidez resultante de estupro; parceiro sexualmente indisponivel ou ausente no ultimo mes; internacao hospitalar no ultimo mes; uso de cremes vaginais nos ultimos 30 dias; gestacao gemelar; uso regular de alcool e/ou drogas ilicitas; uso de medicamentos que interferissem na funcao sexual. Oitenta e sete pacientes preencheram os criterios de selecao e participaram do estudo. Para avaliacao da funcao sexual destes grupos utilizou-se o questionario Quociente Sexual . Versao Feminina (QS-F). Testes X² e t de Student foram utilizados para comparar diferencas entre os grupos, com valores p<0,05 considerados estatisticamente significantes. A analise estatistica foi realizada com o software Instat 3. RESULTADOS: A idade gestacional media nos dois grupos era de 34 semanas. Nao foram detectadas diferencas significantes nos escores medios totais do QS-F nos dois grupos (62,5 saudaveis vs 62,8 DMG, p=0,9). Aproximadamente metade das participantes (47 e 47,5% das saudaveis e DMG, respectivamente, p=0,9) teve escores totais de ate 60 na escala do QS-F, o que indica comprometimento em algum dos dominios avaliados (desejo e satisfacao sexual, excitacao, orgasmo, dispareunia e vaginismo). CONCLUSÕES: A prevalencia de comprometimento do desempenho sexual foi alta em gestantes no terceiro trimestre, nao diferindo significativamente entre mulheres saudaveis e aquelas com DMG.

Conditioned food aversion to Ipomoea carnea var. fistulosa induced by Baccharis coridifolia in goats

Baccharis coridifolia is a plant that induces strong conditioned food aversion in ruminants. This research aimed to induce a conditioned food aversion to Ipomoea carnea var. fistulosa in goats, using B. coridifolia as an aversive agent, and to compare the aversion induced by this plant with the aversion induced by lithium chloride (LiCl). Thirteen goats were allotted into two groups: Group 1 with six goats was averted with 175mg/kg of body weight of LiCl and Group 2 with seven goats was averted with 0,25g/kg of bw of dried B. coridifolia. All goats were averted on day 1 after the ingestion of I. carnea. The aversion procedure with LiCl or B. coridifolia in goats from Groups 1 and 2, respectively, was repeated in those goats that again consumed the plant during tests on days 2, 3, and 7. The goats of both groups were challenged in pens on 23 and 38 days after the last day of aversion and challenged in the pasture on days 11, 15, 18, 20, 22, 25, 27 and 29 after the last day of aversion. After this period goats were challenged every 15 days on pasture until the 330º day after the last day of aversion (7th day). Two goats from Group 1 ingested I. carnea on the first day of the pasture challenge, 4 days after the last day of aversive conditioning in the pen. In addition, another goat in Group 1 started to consume the plant on day 18, and other two goats ate it on day 20. One goat in Group 1 that had never eaten I. carnea died on day 155. One goat from Group 2 started to ingest I. carnea on the first day of the pasture challenge, and a second goat started to consume this plant on day 182. At the end of the experiment, on day 330, the other five goats averted with B. coridifolia remained averted. These results suggest that B. coridifolia or an active compound from the plant could be used to induce aversion to toxic plants. Using B. coridifolia would be cheaper and, particularly in flocks with large number of animals, possibly easier than using LiCl, which requires the use of oral gavage and qualified personnel for its implementation.

Dynamics of coherent vortices in mixing layers using direct numerical and large-eddy simulations

Coherent vortices in turbulent mixing layers are investigated by means of Direct Numerical Simulation (DNS) and Large-Eddy Simulation (LES). Subgrid-scale models defined in spectral and physical spaces are reviewed. The new "spectral-dynamic viscosity model", that allows to account for non-developed turbulence in the subgrid-scales, is discussed. Pseudo-spectral methods, combined with sixth-order compact finite differences schemes (when periodic boundary conditions cannot be established), are used to solve the Navier- Stokes equations. Simulations in temporal and spatial mixing layers show two types of pairing of primary Kelvin-Helmholtz (KH) vortices depending on initial conditions (or upstream conditions): quasi-2D and helical pairings. In both cases, secondary streamwise vortices are stretched in between the KH vortices at an angle of 45° with the horizontal plane. These streamwise vortices are not only identified in the early transitional stage of the mixing layer but also in self-similar turbulence conditions. The Re dependence of the "diameter" of these vortices is analyzed. Results obtained in spatial growing mixing layers show some evidences of pairing of secondary vortices; after a pairing of the primary Kelvin-Helmholtz (KH) vortices, the streamwise vortices are less numerous and their diameter has increased than before the pairing of KH vortices.

Controle de plantas daninhas com cyanazine aplicado em mistura com outros herbicidas, na cultura do algodão (Gossypium hirsutum L.)

Com a finalidade de estudar a mistura de tanque mais eficiente com cyanazine em aplicação de pré-emergência na cultura algodoeira (Gossypium hirsutum L.) , foram estudados os seguintes tratamentos: cyanazine + diuron nas doses de 0,8 + 0,8 kg i.a/ha e 1,0 + 1,0 kg i.a/ha; cyanazine+ oryzalin , nas do sés de 1,2 + 0,8 kg i.a/ha e 1,6 + 1,2 kg i.a/h a; cyanazyne + metol a chlor, nas doses de 1,4 + 2,0 kg i.a/ha e 1,75 + 2,52 kg i.a/ ha;cianazine na dose de 1,75 kg i.a /ha; oryzalin na dose de 1,12 kg i.a/ha; metol achlor na dose de 2,52 kg i.a /ha e diuron na dose de 1,6 kg i.a /ha. Para efeito de comparação, utilizou-se uma testemunha sem capina e outra com capina manual. Nenhum tratamento apresentou injúria para as plantas de algodão e não houve diferenças significativas para o "stand" inicial. Já no "stand" final, a testemunha sem capina apresentou o menor número de plantas, sendo que não houve diferenças significativas dos outros tratamentos com a testemunha capinada. Para o rendimento, a mistura cyanazine + metolachior em ambas as doses estudadas, não apresentaram diferenças significativas da testemunha capinada. Quanto à altura da planta, peso de 100 sementes, porcentagem e índice de fibras não houve diferenças significativas entre os tratamentos estudados, somente o peso do capulho foi afetado pelo oryzalin. Pela avaliação visual (EWRC 1 a 9)*, os herbicidas apres entaram um controle satisfatório somente até os 30 dias após aplicação, sendo que a mistura cyanazine + metolachlor foi efici ente quanto a testemunha capinada. No controle da Portulaca oleracea , a mistura cyanazine + oryzalin na maior dose e oryzalin apresentaram 71,4% de controle ate os 30 dias e 79,4% e 82,4%, respectivamente, até 45 dias da aplicação. Para Amaranthus sp., à exceção da cyanazine e cyanazine + diuron nas doses menores, não apresentaram nenhum controle, sendo que os outros herbicidas controlaram com eficiência superior a 70%. Para Centratherium punctatum, o cyanazine apresentou 78,2% e 73,4%, respectivamente, após 50 e 45 dias da aplicação. Para Cyperus sp e & Brachiaria plantaginea, o metolachlor sozinho ou em mistura com cyanazine, apresentou uma eficiência de 90% para Cyperus sp. e de 70% para B. plantaginea até 45 dias da aplicação. Para as espécies não dominantes (maioria dicotiledôneas), o melhor controle foi de cyanazine + metol achlor na dose maior, com 70,5% e 60,2%, respectivamente, após 30 e 45 dias da aplicação. Para o total das espécies, cyanazine + metolachlor, em ambas doses estudadas, apresentaram controle de 66,2% e 67,3%, respectivamente, após 30 dias e 63,3% e 64,3%, respectivamente, após 45 dias da aplicação. Para as análises tecnológicas da fibra, não houve diferenças significativas na maturação da fibra, uniformidade de comprimento, índice Macronaire e índice Pressley. No comprimento da fibra, a mistura de cyanazine + diuron(0,8+ 0,8 kg ia/h a), apresentou o maior comprimento (26,1 mm) e cyanazine+ metol achlor (1,75 + 2,52 kg i.a / ha),o menor comprimento (24,9 mm), sem diferenças significativas com as testemunhas.

Persistent attenuation and enhancement of the earthworm main muscle contraction generator response induced by repeated stimulation of a peripheral neuron

Responses evoked in the earthworm, Amynthas hawayanus, main muscle contraction generator M-2 (postsynaptic mechanical-stimulus-sensitive) neuron by threshold mechanical stimuli in 2-s intertrial intervals (ITI) were used as the control or unconditioned responses (UR). Their attenuation induced by decreasing these intervals in non-associative conditioning and their enhancement induced by associating the unconditioned stimuli (US) to a train of short (0.1 s) hyperpolarizing electrical substitutive conditioning stimuli (SCS) in the Peri-Kästchen (PK) neuron were measured in four parameters, i.e., peak numbers (N) and amplitude ()averaged from 120 responses, sum of these amplitudes (SAMP) and the highest peak amplitude (V) over a period of 4 min. Persistent attenuation similar to habituation was induced by decreasing the control ITI to 0.5 s and 2.0 s in non-associative conditioning within less than 4 min. Dishabituation was induced by randomly pairing one of these habituated US to an electrical stimulus in the PK neuron. All four parameters of the UR were enhanced by forward (SCS-US), but not backward (US-SCS), association of the US with 25, 100 and 250-Hz trains of SCS with 40-ms interstimulus intervals (ISI) for 4 min and persisted for another 4 min after turning off the SCS. The enhancement of these parameters was proportional to the SCS frequencies in the train. No UR was evoked by the SCS when the US was turned off after 4 min of classical conditioning.

Eye color as an indicator of social rank in the fish Nile tilapia

We investigated the association of eye color with the dominant-subordinate relationship in the fish Nile tilapia, Oreochromis niloticus. Eye color pattern was also examined in relation to the intensity of attacks. We paired 20 size-matched fish (intruder: 73.69 ± 11.49 g; resident: 75.42 ± 8.83 g) and evaluated eye color and fights. These fish were isolated in individual aquaria for 10 days and then their eye color was measured 5 min before pairing (basal values). Twenty minutes after pairing, eye color and fights were quantified for 10 min. Clear establishment of social hierarchy was observed in 7 of 10 pairs of fish. Number of attacks ranged from 1 to 168 among pairs. The quartile was calculated for these data and the pairs were then divided into two classes: low-attack (1 to 111 attacks - 2 lower quartiles) or high-attack (112 to 168 attacks - 2 higher quartiles). Dominance decreased the eye-darkening patterns of the fish after pairing, while subordinance increased darkening compared to dominance. Subordinate fish in low-attack confrontations presented a darker eye compared to dominant fish and to the basal condition. We also observed a paler eye pattern in dominants that shared low-attack interactions after pairing compared to the subordinates and within the group. However, we found no differences in the darkening pattern between dominants and subordinates from the high-attack groups. We conclude that eye color is associated with social rank in this species. Moreover, the association between eye color and social rank in the low-attack pairs may function to reduce aggression.

Effect of the establishment of dominance relationships on cortisol and other metabolic parameters in Nile tilapia (Oreochromis niloticus)

The objective of the present study was to investigate the influence of the establishment of dominance relationships and social stress on plasma cortisol and metabolite levels in Nile tilapia (Oreochromis niloticus). During the 30-day experiment, the fish weighing 236 ± 29 g were kept in individual aquaria, except for two pairings lasting 6 h each. Blood samples were taken from the animals before and after pairing. Display, approach, attack, rebuff, chase flight, and coloration were carried out on days 16 and 30. Activities and behaviors characteristic of the establishment of dominance relationships were described. It was possible to classify all experimental fish (N = 30) as dominant or subordinate. No differences were detected between dominant (N = 15) and subordinate (N = 15) fish during isolation or after pairing in cortisol (isolated: 5.76 ± 0.98 vs 5.42 ± 0.63; paired: 10.94 ± 1.62 vs 11.21 ± 2.45 µg/dl), glucose (isolated: 60.02 ± 4.9 vs 67.85 ± 16.16; paired: 110.44 ± 15.72 vs 136.26 ± 22.46 mg/dl), triglyceride (isolated: 167.87 ± 5.06 vs 185.68 ± 7.24; paired: 210.85 ± 13.40 vs 221.82 ± 12.70 mg/dl) or total protein levels (isolated: 7.01 ± 0.42 vs 6.69 ± 0.59; paired: 9.21 ± 0.62 vs 9.51 ± 0.66 g/dl). However, when isolated (N = 30) and paired (N = 30) tilapia were compared, there were significant differences in cortisol and metabolite levels. The similar response presented by dominant and subordinate tilapia indicates that establishment of dominance relationships was a stressor for both groups.