Fasting: a major limitation for resistance exercise training effects in rodents

Protocols that mimic resistance exercise training (RET) in rodents present several limitations, one of them being the electrical stimulus, which is beyond the physiological context observed in humans. Recently, our group developed a conditioning system device that does not use electric shock to stimulate rats, but includes fasting periods before each RET session. The current study was designed to test whether cumulative fasting periods have some influence on skeletal muscle mass and function. Three sets of male Wistar rats were used in the current study. The first set of rats was submitted to a RET protocol without food restriction. However, rats were not able to perform exercise properly. The second and third sets were then randomly assigned into three experimental groups: 1) untrained control rats, 2) untrained rats submitted to fasting periods, and 3) rats submitted to RET including fasting periods before each RET session. While the second set of rats performed a short RET protocol (i.e., an adaptation protocol for 3 weeks), the third set of rats performed a longer RET protocol including overload (i.e., 8 weeks). After the short-term protocol, cumulative fasting periods promoted loss of weight (P<0.001). After the longer RET protocol, no difference was observed for body mass, extensor digitorum longus (EDL) morphology or skeletal muscle function (P>0.05 for all). Despite no effects on EDL mass, soleus muscle displayed significant atrophy in the fasting experimental groups (P<0.01). Altogether, these data indicate that fasting is a major limitation for RET in rats.

Tempo de destilação e perfil volátil do óleo essencial de aroeira da praia (Schinus terebinthifolius) em Sergipe / Distillation time and volatile profile of the essential oil of Brazilian pepper (Schinus terebinthifolius) in Sergipe, Brazil

Aos frutos e óleos essenciais da aroeira da praia (Schinus terebinthifolius) atribui-se atividade antimicrobiana sobre bactérias gram positivas além de ação anti-inflamatória. O óleo essencial da aroeira é utilizado no tratamento de micoses, sendo a sua atividade antifúngica atribuída à alta concentração de monoterpenos. Este estudo teve como objetivo determinar o melhor rendimento de destilação de óleo essencial de sementes e folhas da aroeira e os componentes químicos do óleo essencial nos diversos períodos de destilação. Cem gramas de cada material foram destilados em aparato de Clevenger durante 2,5h, 4,0h, 5,5h e 7,0h. O material destilado foi analisado por cromatografia a gás acoplada a espectrofotômetro de massas, onde foi obtido o perfil cromatográfico do material. As sementes de aroeira apresentaram maiores quantidades de óleo essencial, quando comparadas com as folhas em todos os períodos de destilação. O óleo essencial de aroeira mostrou perfil volátil formado principalmente por mono e sesquiterpenos.

The fruits and essential oils of Brazilian pepper (Schinus terebinthifolius) have antimicrobial activity against gram-positive bacteria, as well as anti-inflammatory action. The essential oil of Brazilian pepper is used to treat fungal infections, and its antifungal activity is attributed to the high concentration of monoterpenes. This study aimed to determine the best yield of distillation of the essential oil of seeds and leaves of Brazilian pepper and the chemical components of the essential oil in different periods of distillation. One hundred grams of each material were distilled in Clevenger apparatus for 2.5 h, 4.0 h, 5.5 h and 7.0 h. The distilled material was analyzed by gas chromatography coupled to mass spectrometer, where the chromatographic profile of the material was obtained. Seeds of Brazilian pepper showed higher amounts of essential oils when compared with the leaves in all the periods of distillation. The essential oil of Brazilian pepper showed a profile consisting mainly of volatile mono- and sesquiterpenes.

Efeito fungitóxico do óleo essencial de aroeira da praia (Schinus terebinthifolius RADDI) sobre Colletotrichum gloeosporioides / Fungitoxic effect of essential oil from aroeira (Schinus terebinthifolius RADDI) on Colletotrichum gloeosporioides

Neste trabalho foi avaliado o efeito do óleo essencial do fruto de Schinus terebinthifolius sobre o crescimento micelial do fungo Colletotrichum gloeosporioides in vitro, e no desenvolvimento da antracnose no período de pós-colheita em mamões. As diferentes concentrações de óleo foram diluídas em Tween 80 a 8%. No experimento in vitro foram preparados meios de cultura BDA nas concentrações de 0,05; 0,10; 0,25 e 0,50% do óleo essencial. O controle negativo foi realizado apenas com meio BDA e o controle solvente com meio BDA e Tween 80 a 8%. A inibição do crescimento do fungo foi diretamente proporcional à quantidade do óleo e a maior inibição encontrada foi de 79,07% na concentração de óleo de 0,50%. No experimento in vivo os frutos do mamoeiro foram inoculados com o fungo em quatro tratamentos: com biofilme; com biofilme mais 0,50% do óleo; com fungicida Prochloraz e frutos controle. Embora o tratamento com óleo tenha sido eficiente contra o fungo, não foi indicado comercialmente, pois apresentou valores elevados de perda de massa fresca, de firmeza, e também sintomas de fitotoxidade. O óleo tem propriedade antifúngica contra C. gloeosporioides in vitro e in vivo, contudo, não é recomendado para o mamão em função da fitotoxidez.

This study evaluated the effect of essential oil from Schinus terebinthifolius fruit on the mycelial growth of the fungus Colletotrichum gloeosporioides in vitro and on the anthracnose development during the postharvest period of papaya fruits. The different oil concentrations were diluted in 8% Tween 80. For the in vitro experiment, PDA culture media were prepared at the concentrations of 0.05, 0.10, 0.25 and 0.50% essential oil. Negative control was prepared with PDA medium alone, while solvent control was prepared with PDA medium and 8% Tween 80. Fungal growth inhibition was directly proportional to the oil amount and the greatest inhibition was 79.07% at 0.50% oil concentration. For the in vivo experiment, papaya fruits were inoculated with the fungus in four treatments: with biofilm, with biofilm plus 0.50% oil, with the fungicide Prochloraz and control fruits. Although treatment with oil was efficient against the fungus, it was not commercially recommended since it presented high values of loss of fresh mass and firmness, as well as phytotoxicity symptoms. The oil has antifungal property against C. gloeosporioides both in vitro and in vivo; however, it is not recommended for papaya fruits due to its phytotoxicity.

Estimation procedures affect the center of pressure frequency analysis

Even though frequency analysis of body sway is widely applied in clinical studies, the lack of standardized procedures concerning power spectrum estimation may provide unreliable descriptors. Stabilometric tests were applied to 35 subjects (20-51 years, 54-95 kg, 1.6-1.9 m) and the power spectral density function was estimated for the anterior-posterior center of pressure time series. The median frequency was compared between power spectra estimated according to signal partitioning, sampling rate, test duration, and detrending methods. The median frequency reliability for different test durations was assessed using the intraclass correlation coefficient. When increasing number of segments, shortening test duration or applying linear detrending, the median frequency values increased significantly up to 137%. Even the shortest test duration provided reliable estimates as observed with the intraclass coefficient (0.74-0.89 confidence interval for a single 20-s test). Clinical assessment of balance may benefit from a standardized protocol for center of pressure spectral analysis that provides an adequate relationship between resolution and variance. An algorithm to estimate center of pressure power density spectrum is also proposed.

Deformação relativa e frouxidão do tendão calcanear durante mobilização articular passiva através de ultra-sonografia por imagem / Strain and slackness of achilles tendon during passive joint mobilization via imaging ultrasonography

CONTEXTUALIZAÇÃO: O estudo do comportamento das propriedades mecânicas do tendão in vivo pode trazer avanços na avaliação do impacto de programas de intervenção para flexibilidade e força, nas áreas clínica e desportiva. OBJETIVO: O objetivo deste trabalho foi quantificar a deformação (strain) e a frouxidão (slackness) relativas do tendão calcanear, durante mobilização passiva para quatro ângulos articulares do tornozelo e dois do joelho. MATERIAIS E MÉTODOS: O deslocamento da junção miotendínea foi quantificado através de imagens ultra-sonográficas capturadas durante a mobilização passiva do tornozelo, com o auxílio de um eletrogoniômetro e um eletromiógrafo, para garantir as angulações requeridas e a inatividade muscular, respectivamente. RESULTADOS: Os valores de deformação relativa encontrados variaram de 4,28±2,37 a -0,94±1,58 por cento para o joelho estendido e de 2,38±1,63 a -2,32±2,16 por cento para o joelho fletido. CONCLUSÕES: Os valores encontrados ratificam os da literatura, demonstrando a participação do tendão calcanear na variação do comprimento da unidade músculo-tendão, durante movimentação passiva. Estes resultados sugerem que as propriedades mecânicas dos tecidos tendinosos afetam a relação entre o comprimento das fibras e o ângulo articular, até mesmo nesse tipo de movimento.

BACKGROUND: In vivo study of the mechanical behavior of tendons may bring advances in evaluating the impact of intervention programs for flexibility and strength, in clinical practice and sports. OBJECTIVE: The aim of this study was to quantify the relative strain and slackness of achilles tendons during passive mobilization, for four ankle joint angles and two knee angles. METHODS: The displacement of the muscle-tendon junction was quantified by means of ultrasound images acquired during passive ankle mobilization, with the aid of an electrogoniometer and an electromyograph to ensure the achievement of the required angles and muscle inactivity, respectively. RESULTS: The strain values ranged from 4.28 percent±2.37 to -0.94 percent±1.58 for the fully extended knee, and from 2.38 percent±1.63 to -2.32 percent±2.16 percent for the flexed knee. CONCLUSIONS: The values found in this study confirm those in the literature and demonstrate how the Achilles tendon participates in length changes in the muscle-tendon unit during passive movement. These results suggest that the mechanical properties of tendinous tissues affect the relationship between the length of muscle fibers and the joint angle, even during this type of movement.

Genetic diversity and relatedness within and between species of the genus Oligoryzomys (Rodentia; Sigmodontinae)

A RAPD analysis on six species of the rodent genus Oligoryzomys trapped in a wide area (ranging from 01° N to 32° S) of Brazilian territory was performed in order to determine the levels of genetic variability within and between its populations and species. One-hundred and ninety-three animals were collected in 13 different sites (corresponding to 17 samples) located at Pampas, Atlantic Rain Forest, Cerrado, and Amazon domains. Oligoryzomys sp., O. nigripes (8 populations), O. flavescens (4 populations), O. moojeni, O. stramineus, and O. fornesi were the taxa analyzed. Of the 20 primers tested, 4 generated a total of 75 polymorphic products simultaneously amplified in 151 specimens. Various diversity estimators analyzed showed considerable differences between species and populations, indicating a great genetic variation occurring in the Oligoryzomys taxa investigated. A cluster analysis was made using Nei's standard genetic distances, however, it did not correlate the genetic heterogeneity of the species and populations with the geographical areas.

Foram realizadas análises com RAPD em seis espécies de roedores do gênero Oligoryzomys capturados em uma ampla área (estendendo-se de 01° N a 32° S) do território brasileiro com o objetivo de determinar os níveis de variabilidade genética dentro e entre as populações e espécies. Cento e noventa e três animais foram coletados em 13 locais diferentes (correspondendo a 17 amostras) localizados nos Pampas, Floresta Atlântica, Cerrado e Amazônia. Oligoryzomys sp., O. nigripes (8 populações), O. flavescens (4 populações), O. moojeni, O. stramineus e O. fornesi foram as espécies analisadas. Vinte primers foram testados, sendo que quatro deles geraram um total de 75 produtos polimórficos amplificados simultaneamente em 151 exemplares. Várias estimativas de diversidade apresentaram diferenças consideráveis entre as espécies e as populações, indicando uma grande variação genética entre os taxa de Oligoryzomys investigados. As análises de agrupamento utilizando a distância genética de Nei, entretanto, não correlacionaram a heterogeneidade genética das espécies e populações com as áreas geográficas.

Genetic epidemiology of fecal egg excretion during Schistosoma mansoni infection in an endemic area in Minas Gerais, Brazil

There is considerable variation in the level of fecal egg excretion during Schistosoma mansoni infections. Within a single endemic area, the distribution of egg counts is typically overdispersed, with the majority of eggs excreted coming from a minority of residents. The purpose of this study was to quantify the influence of genetic factors on patterns of fecal egg excretion in a rural study sample in Brazil. Individual fecal egg excretions, expressed in eggs per gram of feces, were determined by the Kato-Katz method on stool samples collected on three different days. Detailed genealogic information was gathered at the time of sampling, which allowed assignment of 461 individuals to 14 pedigrees containing between 3 and 422 individuals. Using a maximum likelihood variance decomposition approach, we performed quantitative genetic analyses to determine if genetic factors could partially account for the observed pattern of fecal egg excretion. The quantitative genetic analysis indicated that between 21-37 percent of the variation in S. mansoni egg counts was attributable to additive genetic factors and that shared environment, as assessed by common household, accounted for a further 12-21 percent of the observed variation. A maximum likelihood heritability (h²) estimate of 0.44 ± 0.14 (mean ± SE) was found for the 9,604 second- and higher-degree pairwise relationships in the study sample, which is consistent with the upper limit (37 percent) of the genetic factor determined in the variance decomposition analysis. These analyses point to the significant influence of additive host genes on the pattern of S. mansoni fecal egg excretion in this endemic area

Antinociceptive property of new 4-acyl-arylhydrazone pyrazole compounds

A series of new 4-acyl-arylhydrazone pyrazole compunds were tested for antinociceptive activity using the inhibition of abdominal contortions induced by acetylcholine (4 mg/Kg, ip) in the mouse. Dipyrone was used for comparison of the antinociceptive potency of the compounds being tested. All drugs wee administered po in saline (dipyrone) or in propylene flycol 94-acyl-arylhydrazones). The maximum response induced by dipyrone (86% inhibition) was assigned an efficacy index of 1.0. Although none of the compounds had an efficacy index greater than 1.0, all three reached 1.0. The two most potent compounds, Wd1 and W1g, which also had an efficacy similar to that of dipyrone, contain a p-N(CH3)2 and m-OH,p-OCH3 group in the aromatic ring of the acyl-hydrazone, respectively. W1d presented the lowest antinociceptive ED50 in the series (1.41 mg/Kg) and was eleven times more potent than dypyrone (ED50 = 15.80 mg/Kg). Other substitutions at the para position had lower potency than W1d. The present results indicate that the introduction of a group at the para postion of the acyl-arylhydrazone ring increases the antinociceptive activity of these compounds to provide compounds of the same efficacy but greater potency than dipyrone to which these new compounds ara structurally related. Other assays of nociceptive activity are veing used to characterize the mechanism of action of the potential new drugs

Estudo clínico multicêntrico com alfentanil / A multicenter clinical trial with alfentanil

Em estudo clínico multicêntrico realizado em cinco instituiçöes hospitalares brasisleiras, foram avaliadas as características da anestesia obtida com a associaçäo de alfentanil em infusäo venosa venosa contínua e óxido nitroso a 50% . Foram estudados 67 pacientes submetidos a diversos tipos de cirurgias. A anestesia foi induzida com alfentanil (39,9 ñ 11,4 microng.Kg-1) e tiopental 3,7 ñ 1,01 mg.Kg-1) e mantida com óxido nitroso a 50% em oxigênio mais a infusäo de alfentanil. A velocidade de infusäo teve variaçäo individual apreciavel mas em 46,3% dos pacientes ficou entre 1,0 e 1,5 microng.Kg-1.min-1. A estabilidadade dos parâmetros cardiovasculares com a técnica foi notável, o mesmo näo se podendo dizer dos parâmetros respiratórios: 9 entre os 24 pacientes (37,5% ) apresentaram apnéia após a induçäo e 17 entre 67 pacientes (25,4% ), depressäo rspiratória pós-anestésica. A regressäo da anestesia foi relativamente rápida e a técnica näo conferiu analgesia residual: apenas 14,3% dos pacientes tiveram analgesia por tempo superior a uma hora ao final da cirurgia

Efeito hemodinâmico da lidocaína em cäes / Hemodynamic effects of lidocaine in dogs

Em doze cäes anestesiados pela cloralose e submetidos a condiçöes controladas de ventilaçäo, estudou-se o efeito hemodinâmico produzido pela infusäo venosa de lidocaína (6 mg. kg-1 min-1, dose total 24 mg. kg-1). Durante o efeito máximo da lidocaína, verificou-se intensa depressäo da atividade mecânica e elétrica do coraçäo caracterizada por reduçäo da dp/dt máxima do ventrículo esquerdo (-67%), do débito cardíaco (-45%) e da freqüência cardíaca (-23%). A pressäo média do átrio direito elevou-se em 69%. Näo se evidenciou-se qualquer efeito vasodilatador direto da lidocaína. A resistência vascular periférica total näo variou de forma significativa. A pressäo arteiral média reduziu-se de 32% e o consumo de oxigênio miocárdio (variaçäo do duplo produto PS x FC) também se reduziu de 47%. A reduçäo da contratilidade e do débito cardíaco perdurou por mais de 10 minutos. A pressäo arterial, por outro lado, retornou aos valores de controle mais rapidamente, compensada por um aumento da resistência vascular periférica. Concluiu-se que doses tóxicas de lidocaína produzem depressäo hemodinâmica de origem cardíaca e näo vascular, em animais sob condiçöes normais de ventilaçäo

Uso del verapamil en arritmias durante la anestesia general con halothano. Analisis hemodinamico. / Use of verapamil in arrhythmia during general anesthesia with halothane. Hemodynamic analysis

Se estudio en 16 perros sometidos a anestesia general con halothano el efecto hemodinamico y la actividad antiarritmica del verapamil en las arritmias inducidas por la infusion endovenosa de adrenalina (5 ug/kg/min.). Se observo que el verapamil (0,2 mg/kg) administrado en cinco minutos reduce la resistencia vascular periferica (RVP), aumenta el volumen sistolico (VS) y el volumen minuto (VM), reduce la frecuencia cardiaca (FC), no altera el dP/d/T, prolonga el segmento PR, reduce discretamente la presion arterial (PA) y el consumo de O2 por el miocardio. En dosis de 0.5 mg/kg administrado en 15 min. se observa una caida acentuada de la PA, RVP, FC y del dP/d/T sin alterarse el volumen minuto. La aparicion del bloqueo AV de segundo grado (2:1) en los animales refleja una gran depresion de la conduccion auriculo-ventricular, no reversible por la atropina pero si con adrenalina. Tanto con 0.2 como con 0.5 mg/kg el verapamil fue bastante eficaz en la prevension de las arritmias. Se concluye que el verapamil en dosis de 0.2 mg/kg previene las arritmias de origen adrenergico durante la anestesia con halothano no provocando depresion cardiocirculatoria significativa