Mild-to-moderate COVID-19 impact on the cardiorespiratory fitness in young and middle-aged populations

The goal of the present study was to compare pulmonary function test (PFT) and cardiopulmonary exercise test (CPET) performance in COVID-19 survivors with a control group (CG). This was a cross-sectional study. Patients diagnosed with COVID-19, without severe signs and symptoms, were evaluated one month after the infection. Healthy volunteers matched for sex and age constituted the control group. All volunteers underwent the following assessments: i) clinical evaluation, ii) PTF; and iii) CPET on a cycle ergometer. Metabolic variables were measured by the CareFusion Oxycon Mobile device. In addition, heart rate responses, peak systolic and diastolic blood pressure, and perceived exertion were recorded. Twenty-nine patients with COVID-19 and 18 healthy control subjects were evaluated. Surviving patients of COVID-19 had a mean age of 40 years and had higher body mass index and persistent symptoms compared to the CG (P<0.05), but patients with COVID-19 had more comorbidities, number of medications, and greater impairment of lung function (P<0.05). Regarding CPET, patients surviving COVID-19 had reduced peak workload, oxygen uptake (V̇O2), carbon dioxide output (V̇CO2), circulatory power (CP), and end-tidal pressure for carbon dioxide (PETCO2) (P<0.05). Additionally, survivors had depressed chronotropic and ventilatory responses, low peak oxygen saturation, and greater muscle fatigue (P<0.05) compared to CG. Despite not showing signs and symptoms of severe disease during infection, adult survivors had losses of lung function and cardiorespiratory capacity one month after recovery from COVID-19. In addition, cardiovascular, ventilatory, and lower limb fatigue responses were the main exercise limitations.

Reliability and validity of six-minute step test in patients with heart failure

Exercise intolerance is the hallmark consequence of advanced chronic heart failure (HF). The six-minute step test (6MST) has been considered an option for the six-minute walk test because it is safe, inexpensive, and can be applied in small places. However, its reliability and concurrent validity has still not been investigated in participants with HF with reduced ejection fraction (HFrEF). Clinically stable HFrEF participants were included. Reliability and error measurement were calculated by comparing the first with the second 6MST result. Forty-eight hours after participants underwent the 6MST, they were invited to perform a cardiopulmonary exercise test (CPET) on a cycle ergometer. Concurrent validity was assessed by correlation between number of steps and peak oxygen uptake (V̇O2 peak) at CPET. Twenty-seven participants with HFrEF (60±8 years old and left ventricle ejection fraction of 41±6%) undertook a mean of 94±30 steps in the 6MST. Intra-rater reliability was excellent for 6MST (ICC=0.9), with mean error of 4.85 steps and superior and inferior limits of agreement of 30.6 and -20.9 steps, respectively. In addition, strong correlations between number of steps and CPET workload (r=0.76, P<0.01) and peak V̇O2 (r=0.71, P<0.01) were observed. From simple linear regression the following predictive equations were obtained with 6MST results: V̇O2 peak (mL/min) = 350.22 + (7.333 × number of steps), with R2=0.51, and peak workload (W) = 4.044 + (0.772 × number of steps), with R2=0.58. The 6MST was a reliable and valid tool to assess functional capacity in HFrEF participants and may moderately predict peak workload and oxygen uptake of a CPET.

Validation of the two-minute step test in obese with comorbibities and morbidly obese patients

Cardiopulmonary fitness assessment is a valuable resource to obtain quantitative indicators of an individual's physical performance. The cardiopulmonary exercise test (CPX), considered the gold standard test for this evaluation, is costly and difficult to be accessed by the general population. In order to make this evaluation more accessible, and to better reflect the performance of daily life activities, alternative tests were proposed. Morbidly obese patients present limitations that impair physical performance assessment and could benefit from a test of shorter duration, provided it is validated. This observational study aimed to validate the two-minute step test (2MST) as a tool to evaluate functional capacity (FC) in obese with comorbidities and morbidly obese patients, compared the 2MST with CPX as a measure of physical performance, and developed a predictive equation to estimate peak oxygen uptake (VO2) in the 2MST. The CPX and the 2MST were performed and metabolic and ventilatory parameters were recorded in 31 obese individuals (BMI>35 kg/m2). Pearson correlation and multiple linear regression analyses were performed to evaluate the peak VO2 best predictors. Bland-Altman analysis was performed to assess the agreement between the two methods. Peak VO2 measured by CPX and 2MST showed a strong correlation (r=0.70, P<0.001) and there was a moderate correlation between peak VO2 of the 2MST and the number of up-and-down step cycles (UDS) (r=0.55; P=0.01). The reference equation obtained was: VO2 (mL·kg-1·min-1) = 13.341 + 0.138 × total UDS - (0.183 × BMI), with an estimated standard error of 1.3 mL·kg-1·min-1. The 2MST is a viable, practical, and easily accessible test for FC. UDS and BMI can predict peak VO2 satisfactorily.

The mediational role of distracting stimuli in emotional word recognition

Abstract Emotions are considered distractions that often prompt subsequent actions. In this way, the aim of this work was to examine the role of distracting stimuli on the relationship of RT and accuracy. In order to do that, a word recognition task was carried out in which emotional valence was manipulated. More precisely, a mediational model, testing how changes in distracting stimuli mediate RT predicting accuracy across emotional conditions, was carried out. The results suggest that changes in task demands should distract from the secondary task to the extent that these task demands implicate and affect accuracy. Moreover, the distracting task seems to mediate between accuracy and the target task under emotional stimuli, showing the negative distracting condition to be the most remarkable effect. Furthermore, neutral distracting latencies did not affect accuracy. Understanding the mechanisms by which emotion impairs cognitive functions has important implications in several fields, such as affective disorders. However, the effects of emotion on goal-directed cognitive processing remain unclear.

Does the incremental shuttle walk test require maximal effort in young obese women?

Obesity is a chronic disease with a multifaceted treatment approach that includes nutritional counseling, structured exercise training, and increased daily physical activity. Increased body mass elicits higher cardiovascular, ventilatory and metabolic demands to varying degrees during exercise. With functional capacity assessment, this variability can be evaluated so individualized guidance for exercise training and daily physical activity can be provided. The aim of the present study was to compare cardiovascular, ventilatory and metabolic responses obtained during a symptom-limited cardiopulmonary exercise test (CPX) on a treadmill to responses obtained by the incremental shuttle walk test (ISWT) in obese women and to propose a peak oxygen consumption (VO2) prediction equation through variables obtained during the ISWT. Forty obese women (BMI ≥30 kg/m2) performed one treadmill CPX and two ISWTs. Heart rate (HR), arterial blood pressure (ABP) and perceived exertion by the Borg scale were measured at rest, during each stage of the exercise protocol, and throughout the recovery period. The predicted maximal heart rate (HRmax) was calculated (210 – age in years) (16) and compared to the HR response during the CPX. Peak VO2 obtained during CPX correlated significantly (P<0.05) with ISWT peak VO2 (r=0.79) as well as ISWT distance (r=0.65). The predictive model for CPX peak VO2, using age and ISWT distance explained 67% of the variability. The current study indicates the ISWT may be used to predict aerobic capacity in obese women when CPX is not a viable option.

Toxicidade e repelência de extratos de plantas da caatinga sobre Tetranychus bastosi Tutler, Baker & Sales (Acari: Tetranychidae) em pinhão-manso / Toxicity and repellency of caatinga plant extracts on the Tetranychus bastosi Tutler, Baker & Sales in physic nut

RESUMO O objetivo deste trabalho foi avaliar o efeito repelente e a toxicidade dos extratos aquosos de Myracrodruon urundeuva Fr. All (Anacardiaceae), Croton blanchetianus Baill (Euphorbiaceae) e Ziziphus joazeiro Mart. (Rhamnaceae,) sobre o ácaro Tetranychusbastosi Tutler, Baker & Sales associado à cultura do pinhão- manso Jatropha curcas L. Para cada extrato as concentrações utilizadas foram 0, 5%, 10%, 15%, 20% e 25%. Avaliou-se, em teste sem chance de escolha, a mortalidade de fêmeas adultas de T. bastosi submetidas às diferentes concentrações de cada extrato. O delineamento estatístico foi o inteiramente casualizado, com seis tratamentos (testemunha e concentrações dos extratos) e 10 repetições. Os dados foram submetidos à análise de regressão. Também foi avaliado o efeito repelente dos referidos extratos sobre T. bastosi, nas concentrações supracitadas. Foi calculado o índice de repelência, percentual de repelência, classificação e índice de segurança. Os dados de percentual de repelência de adultos no tratamento e testemunha foram analisados pelo teste T de Student a 5% de probabilidade. De uma forma geral os extratos demonstraram efeito tóxico para adultos de T. bastosi nas concentrações testadas. O extrato de Z. joazeiro apresentou as maiores taxas de mortalidade (90%) média dos indivíduos. No que se refere à repelência destes extratos, todos os tratamentos se mostraram repelentes para fêmeas de T. bastosi, classificados como tratamentos repelentes, exceto para a dosagem de 5% do extrato de M. unrundeuva.

ABSTRACT The aim of this study was to evaluate the repellent effect and toxicity of aqueous extracts of M. urundeuva All Br. (Anacardiaceae), Crotonblanchetianus Baill( Euphorbiaceae ) and Ziziphus joazeiro Mart. (Rhamnaceae) on the mite Tetranychus bastosi Tutler, Baker & Sales associated with Jatropha curcas. For each extract, the concentrations used were 0, 5%, 10 %, 15 %, 20% and 25%. It was evaluated, at a no-choice test, the mortality of adult females of T. bastosi submitted to different concentrations of each extract. The experimental design was completely randomized with six treatments (control and concentrations of the extracts) and 10 repetitions. The data were subjected to regression analysis. The repellent effect of the extracts over the T. bastosi, in the concentrations already mentioned was also evaluated. The repellency index, percentage repellency, classification and safety index were assessed. The data of percentage repellency of adults in treatment and control were analyzed by the T test Student a 5% probability. In general, the extracts showed toxic effect on adults of T. bastosi for the concentrations tested. The extract of Z. joazeiro indicated d the highest average mortality rates (90 %) of individuals. Regarding the repellency of these extracts, all treatments have proved to be repellants for the females of T. bastosiclassified as repellent treatment, except for the 5% dose of the extract of M. unrundeuva.

Potencial inseticida de óleos essenciais sobre Tribolium castaneum em milho armazenado / Insecticidal potential of essential oils on Tribolium castaneum in stored maize

RESUMO O presente trabalho teve como objetivo investigar o potencial inseticida de óleos essenciais de Croton heliotropiifolius, Croton pulegiodorus, Myracrodruon urundeuva e Ocimumbasilicum sobre adultos de Tribolium castaneumem milho armazenado. Para cada óleo foram realizados bioensaios de fumigação, repelência e o efeito sobre a taxa instantânea de crescimento (ri), em cinco concentrações (0; 5; 10; 15 e 20 μL). Os bioensaios foram conduzidos sob condições constantes de temperatura (28±2 ºC), umidade relativa (70±5%) e escoto fase de 24 horas. Nos testes de fumigação diferentes concentrações dos óleos foi aplicado em tiras de papel filtro presas na parte inferior da tampa da câmara de fumigação (1,5L), a qual continha 20 gramas de substrato alimentar e 10 insetos adultos de T. castaneum não sexados. A mortalidade dos insetos foi avaliada após 48 horas de exposição. Os testes de repelência foram efetuados em arenas compostas por dois frascos ligados a uma caixa central. Em um frasco foi depositado o substrato alimentar com diferentes concentrações do óleo essencial, e, no outro, foi depositado apenas alimento (testemunha). Dez insetos adultos foram liberados na caixa central, ficando expostos por 5 dias para avaliação da preferência. Nos bioensaios de fumigação observou-se atividade inseticida do óleo essencial de M. urundeuva sobre adultos de T. castaneum. Nos bioensaios de repelência, todos os óleos testados apresentaram efeito repelente. A emergência de T. castaneumreduziu entre 33 e 100% quando foram criados em pó de milho tratado com os óleos essenciais. Os óleos essenciais de C. pulegiodorus e O. basilicum ocasionaram redução do crescimento populacional de T. castaneum em grãos de milho tratados. Os óleos testados demonstraram ser uma alternativa eficiente de controle para o uso nos programas de manejo de T. castaneum em unidades armazenadoras.

ABSTRACT The current work aimed at to investigate the insecticide potential of essential oils of Croton heliotropiifolius, Croton pulegiodorus, Myracrodruon urundeuva and Ocimum basilicum on adults of Tribolium castaneum in stored maize. For each oil, it were performed fumigation tests, repellency and the effect on the instantaneous rate of increase (ri), in five concentrations (0; 5; 10; 15 e 20 μL). Bioassays were carried out under constant temperature conditions (28±2 °C), relative humidity (70±5%) and scot phase of 24 hours. In fumigation different concentrations of test oils were applied on filter paper strips attached on the bottom of the fumigation chamber cover (1.5 L), which contained 20 grams of food substrate and 10 unsexed adults of T. castaneum. The insect mortality was recorded after 48 hours of exposure. The repellency tests were performed in arenas composed of two pots connected to a central box. In a pot it was deposited feed substrate, with concentrations of the essential oil, in the other pot (control) it was deposited only food. Ten adult insects were released in the central box, being exposed for 5 days to evaluate the preference. In the fumigation tests, insecticide activity of the essential oil of M. urundeuva was observed on adults of T. castaneum. In the repellency tests, all the tested oils presented repellent effect. The emergency of T. castaneumreduced between 33% and 100% when they were in the powdered maize treated with the essential oils. Maize grains treated with C. pulegiodorus and O. basilicum essential oils caused a significant decrease in the populations of T. castaneum. The tested oils proved to be an efficient control alternative for the use in managing programs of T. castaneum in storing units.

Composição físico-química e valores energéticos de farinhas de silagem de peixe para frangos de corte / Physicochemical composition and energy values of fish silage meal for broilers

Objetivou-se determinar a composição físico-química, os valores energéticos e os coeficientes de digestibilidade de quatro farinhas de silagem de peixe para frangos de corte. Foram produzidas quatro farinhas de silagem de peixe, utilizando-se o resíduo da filetagem de tilápias ensilado com diferentes fontes de carboidratos fermentáveis. Analisou-se a composição físico-química das silagens, e, em seguida, um ensaio de metabolismo com 180 pintos machos da linhagem Cobb de 14 a 25 dias de idade. Também foram avaliados o tempo de trânsito gastrintestinal das rações e o desempenho das aves nas gaiolas. Os animais foram distribuídos em delineamento inteiramente ao acaso, com cinco tratamentos, seis repetições e seis aves por unidade experimental. Os tratamentos consistiram de uma dieta referência e de quatro dietas teste compostas de 60 porcento da ração referência e 40 porcento do resíduo da filetagem de tilápia ensilado com diferentes fontes de carboidratos, sendo a farinha de silagem de peixe com o farelo de algaroba (SFA), com a farinha de varredura de mandioca (SFVM), com o farelo de milho (SFM) e com a casca da mandioca (SCM). A SFM obteve o maior teor de PB, 22,38 porcento, de EE, 27,35 porcento, e o maior tempo de trânsito, com 195,0min; a SCM apresentou o maior valor de MM, 11,12 porcento. Os valores de EMA e EMAn das farinhas de silagem de peixe não diferiram significativamente entre eles. O maior GP e a melhor CA foram apresentados pelos animais do tratamento SFM, e os piores GP e CA pelos frangos de corte alimentados com dietas contendo a SFVM. Com base na composição obtida, estas silagens de peixe têm potencialidade para serem utilizadas em dietas para frangos de corte...

The objective of this research was to determine the physical and chemical composition energy value and digestibility of four fish silage meal for broilers. Four flours were produced from fish silage using the residue of tilapia filleting ensiled together with different sources of fermentable carbohydrates. We analyzed the physical and chemical composition of silages and then a metabolism trial with 180 male Cobb chicks 14-25 days old, and also evaluated gastrintestinal transit time of feed and performance of birds in cages. The animals were distributed in a completely randomized design with five treatments and six replicates of six birds each. Treatments consisted of a reference diet and four test diets composed of 60 percent of the reference diet with the inclusion of 40 percent of the residue of tilapia silage with different sources of carbohydrates, and the fish silage meal with bran mesquite (SFA) with the scan cassava flour (SFVM) with corn meal (SFM), and peel cassava (SCM). The SFM had the highest content of CP, 22.38 percent, EE, 27.35 percent, and the largest transit time with 195.0 min, the SCM showed the highest MM, 11.12 percent. The AME and AMEn of flour fish silage did not differ significantly between them. The biggest and best GP CA was presented by animals in the SFM treatment and the worse CA GP was for broilers fed diets containing SFVM. Based on the composition obtained, these fish silage have the potential to be used in diets for broilers...

Óleo essencial de Baccharis trimera (Less. ) DC. sobre o potencial fisiológico de sementes de feijão caupi / The essential oil effects of Baccharis trimera (Less. ) DC. on the physiological potential of cowpea bean seeds

O presente trabalho teve como objetivo avaliar o efeito alelopático do óleo essencial de plantas de carqueja, Baccharis trimera (Less.) DC., sobre a germinação de sementes de feijão Vigna unguiculata (L.) Walp. Foi avaliado o efeito do óleo essencial de B. trimera sobre V. unguiculata nas dosagens 20 μL, 15 μL, 10 μL, 5 μL e testemunha. A qualidade fisiológica das sementes foi determinada pela porcentagem de emergência, velocidade de emergência e índice de velocidade de emergência. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 5 x 2 com cinco repetições. Não foi observado efeito inibidor do óleo essencial de B. trimera na germinação de sementes de feijão caupi, caracterizando-se como de efeito alelopático benéfico. De acordo com os resultados obtidos, o óleo essencial de B. trimera revelou-se eficiente na manutenção da viabilidade dessas sementes.

This research aimed to evaluate the allellopathic effect of essential oils of the Baccharis trimera (Less.) DC. plants on the seeds germination of cowpea Vigna unguiculata (L.) Walp. The effect of B. trimera essential oil on V. unguiculata was evaluated at levels of 20 μL, 15 μL, 10 μL, 5 μL and control. The physiologic quality of the seeds was determined by percentage emergence, the rate of speed emergence and speed emergence index. The data analysis was carried out using an entirely randomized design, in a 5 x 2 factorial scheme with five repetitions. An inhibitory effect of B. trimera essential oil on bean seeds germination was not observed, which is characterized as a beneficial allelopathic effect. Based on the results, the B. trimera essential oil proved efficient in the viability maintenance of these seeds.

Viabilidade de sementes de feijão caupi após o tratamento com óleo essencial de citronela (Cymbopogon winterianus Jowitt) / Viability of Vigna unguiculata bean seeds treated with essential oil of Java grass (Cymbopogon winterianus Jowitt)

O tratamento de sementes com óleos essenciais é um método alternativo que auxilia o manejo integrado de pragas. O objetivo deste trabalho foi avaliar a influência do tratamento de sementes de feijão Vigna unguiculata (L.) Walp. com o óleo essencial de citronela (Cymbopogon winterianus Jowitt). Foi avaliado o efeito do óleo essencial de C. winterianus sobre V. unguiculata nas dosagens 20 µL, 15 µL, 10 µL, 5 µL e testemunha. A qualidade fisiológica das sementes foi determinada pela porcentagem de emergência, velocidade de emergência e índice de velocidade de emergência. A análise dos dados foi realizada no delineamento inteiramente casualizado, disposto em esquema fatorial 5 x 2 com cinco repetições. As sementes fumigadas apresentaram diferenças estatísticas entre os parâmetros avaliados em relação à testemunha. O óleo essencial de citronela revelou potencialidade alelopática sobre a germinação de sementes de feijão que variou de acordo com a concentração do óleo.

Seed treatment with essential oils is an alternative method tool in integrated pest management. The objective of this study was to evaluate the effect of treating Vigna unguiculata (L.) Walp. bean seeds with essential oil of Java grass (Cymbopogon winterianus Jowitt). The effect of C. winterianus essential oil on P. vulgaris was evaluated at levels of 20 µL, 15 µL, 10 µL, 5 µL and control. The physiologic quality of the seeds was determined by percentage emergence, speed emergence and speed emergence index. The data analysis was carried out using an entirely randomized design, in a 5 x 2 factorial scheme with five repetitions. The fumigated bean seeds showed the statistics differences among the analyzed parameters when was compared with the no treated check. The essential oil of Java grass revealed allelopathic potentiality on bean seed germination which varied according to the oil concentration.

Purification and n-terminal sequencing of two presynaptic neurotoxic PLA2, neuwieditoxin-I and neuwieditoxin-II, from Bothrops neuwiedi pauloensis (jararaca pintada) venom

Two presynaptic phospholipases A2 (PLA2), neuwieditoxin-I (NeuTX-I) and neuwieditoxin-II (NeuTX-II), were isolated from the venom of Bothrops neuwiedi pauloensis (BNP). The venom was fractionated using molecular exclusion HPLC (Protein-Pak 300SW column), followed by reverse phase HPLC (æBondapak C18 column). Tricine-SDS-PAGE in the presence or absence of dithiothreitol showed that NeuTX-I and NeuTX-II had a molecular mass of approximately 14 kDa and 28kDa, respectively. At 10æg/ml, both toxins produced complete neuromuscular blockade in indirectly stimulated chick biventer cervicis isolated preparation without inhibiting the response to acetylcholine, but NeuTX-II reduced the response to KCl by 67.0±8.0 percent (n=3; p<0.05). NeuTX-I and NeuTX-II are probably responsible for the presynaptic neurotoxicity of BNP venom in vitro. In fact, using loose patch clamp technique for mouse phrenic nerve-diaphragm preparation, NeuTX-I produced a calcium-dependent blockade of acetylcholine release and caused appearance of giant miniature end-plate potentials (mepps), indicating a pure presynaptic action. The N-terminal sequence of NeuTX-I was DLVQFGQMILKVAGRSLPKSYGAYGCYCGWGGRGK (71 percent homology with bothropstoxin-II and 54 percent homology with caudoxin) and that of NeuTX-II was SLFEFAKMILEETKRLPFPYYGAYGCYCGWGGQGQPKDAT (92 percent homology with Basp-III and 62 percent homology with crotoxin PLA2). The fact that NeuTX-I has Q-4 (Gln-4) and both toxins have F-5 (Phe-5) and Y-28 (Tyr-28) strongly suggests that NeuTX-I and NeuTX-II are Asp49 PLA2.

Neuromuscular activity of Bothrops neuwiedi pauloensis snake venom in mouse nerve-muscle preparations

The pharmacological effects of Bothrops neuwiedi pauloensis venom on mouse phrenic nerve-diaphragm (PND) preparations were studied. Venom (20 mug/ml) irreversibly inhibited indirectly evoked twitches in PND preparations (60 ± 10 percent inhibition, mean ± SEM; p<0.05; n=6). At 50 mug/ml, the venom blocked indirectly and directly (curarized preparations) evoked twitches in mouse hemidiaphragms. In the absence of Ca2+, venom (50 mug/ml), produced partial blockade only after an 80 min incubation, which reached 40.3 ± 7.8 percent (p<0.05; n=3) after 120 min. Venom (20 mug/ml) increased (25 ± 2 percent, p< 0.05) the frequency of giant miniature end-plate potentials in 9 of 10 end-plates after 30 min and the number of miniature end-plate potentials which was maximum (562 ± 3 percent, p<0.05) after 120 min. During the same period, the resting membrane potential decreased from - 81 ± 1.4 mV to - 41.3 ± 3.6 mV 24 fibers; p<0.01; n=4) in the end-plate region and from - 77.4 ± 1.4 to -44.6 ± 3.9 mV (24 fibers; p<0.01; n=4) in regions distant from the end-plate. These results indicate that B. n. pauloensis venom acts primarily at presynaptic sites. They also suggest that enzymatic activity may be involved in this pharmacological action.(AU)

Xantoastrocitoma Pleomórfico: relato de um caso. (Aspectos histopatológicos e terapêuticos) / Pleomorphic Xantoastrocytoma: case report. (Hystophatological and therapeutic aspects)

Os autores apresentam um caso de xantoastrocitoma pleomórfico e discutem a incidência, a apresentação clínica, os aspectos histopatológicos e a conduta terapêutica deste raro tipo de glioma. O controle das crises convulsivas foi obtido pela ressecção do tumor

IgA response in serum and gut secretion in sensitized mice fed with the dust mite Dermatophagoides pteronyssinus extract

Induced oral tolerance to mucosal-exposed antigens in immunized animals is of particular interest for the development of immunotherapeutic approaches to human allergic diseases. This is a unique feature of mucosal surfaces which represent the main contact interface with the external environment. However, the influence of oral tolerance on specific and natural polyreactive IgA antibodies, the major defense mechanism of the mucosa, is unknown. We have shown that oral administration of an extract of the dust mite Dermatophagoides pteronyssinus (Dp) to primed mice caused down-regulation of IgE responses and an increase in tumor growth factor-á secretion. In the present study, we observed that primed inbred female A/Sn mice (8 to 10 weeks old) fed by gavage a total weight of 1.0-mg Dp extract on the 6th, 7th and 8th days post-immunization presented normal secretion of IL-4 and IL-10 in gut-associated lymphoid tissue and a decreased production of interferon gamma induced by Dp in the draining lymph nodes (13,340 ñ 3,519 vs 29,280 ñ 2,971 pg/ml). Mice fed the Dp extract also showed higher levels of serum anti-Dp IgA antibodies and an increase of IgA-secreting cells in mesenteric lymph nodes (N = 10), reflecting an increase in total fecal IgA antibodies (N = 10). The levels of secretory anti-Dp IgA antibodies increased after re-immunization regardless of Dp extract feeding. Oral tolerance did not interfere with serum or secretory IgA antibody reactivity related to self and non-self antigens. These results suggest that induction of oral tolerance to a Dp extract in sensitized mice triggered different regulatory mechanisms which inhibited the IgE response and stimulated systemic and secretory IgA responses, preserving the natural polyreactive IgA antibody production.

The pharmacological effect of Bothrops neuwiedii pauloensis (jararaca-pintada) snake venom on avian neuromuscular transmission

The neuromuscular effects of Bothrops neuwiedii pauloensis (jararaca-pintada) venom were studied on isolated chick biventer cervicis nerve-muscle preparations. Venom concentrations of 5-50 æg/ml produced an initial inhibition and a secondary increase of indirectly evoked twitches followed by a progressive concentration-dependent and irreversible neuromuscular blockade. At venom concentrations of 1-20 æg/ml, the responses to 13.4 mM KCl were inhibited whereas those to 110 æM acetylcholine alone and cumulative concentrations of 1 æM to 10 mM were unaffected. At venom concentrations higher than 50 æg/ml, there was pronounced muscle contracture with inhibition of the responses to acetylcholine, KCl and direct stimulation. At 20-24ºC, the venom (50 æg/ml) produced only partial neuromuscular blockade (30.7 ± 8.0 percent, N = 3) after 120 min and the initial inhibition and the secondary increase of the twitch responses caused by the venom were prolonged and pronounced and the response to KCl was unchanged. These results indicate that B.n. pauloensis venom is neurotoxic, acting primarily at presynaptic sites, and that enzyme activity may be involved in this pharmacological action

Intraspecific variation in neurotoxic and myotoxic activities of Bothrops neuwiedii venoms

Snake venoms frequently vary in composition. In this work, we compared the neurotoxic and myotoxic activities of 16 lots of Bothrops neuwiedii venoms from different regions of Brazil, using chick biventer cervicis preparations. The neuromuscular blockade varied from 2 per cent to 100 per cent after 120 min incubation with venoms (50µg/ml). In all cases, this blockade was irreversible and concentration-dependent; at low concentrations (10-20 µg/ml), 15 of the 16 venom lots failed to abolish responses to acetylcholine (110µM), but blocked responses to KCI (13.4mM), and induced contracture. At 5-20µg/ml, the most active venom totally blocked twitch-tension without affecting responses to acetylcholine and KCI. Polyacrylamine gel electrophoresis for basic proteins showed that the most active samples contained a band that was absent in the less active venoms. These results indicate that there may be considerable intraspecific variation in the neurotoxic activity of B. ineuwiedii venoms, whereas myotoxic activity is less variable.

Quiste del colédoco en niños: experiencia en 15 casos / Choledocal cyst in children: 15 years experience

Presentamos la experiencia del Servicio de Cirugía Pediátrica del Hospital de Clínicas de la universidadFederal de Minas Gerais en quistes colédoco,con 19 niños tratados en el período de 1984 a 1998,ocho eranmenores de 2 años de edad,7 de los cuales presentaban ictericia obstructiva y acolia.A partir de los dosaños solamente 3 de los 11 niños manifestaban la tríada sintomática de ictericia,dolor y masa abdominal.En 18 pacientes se realizó la estirpación de la vesícula,del quiste y una hepaticoyeyunostomía en Y de Roux.En dos de ellos con severa inflamación periquística,fue realizada la resección intramural del quistey en otro paciente,con inflamación periquística se realizó una quisteyeyunostomía en Y de Roux y colecistectomía '