High specialisation in the pollination system of Mandevilla tenuifolia (J.C. Mikan) Woodson (Apocynaceae) drives the effectiveness of butterflies as pollinators.

Butterfly pollination in the tropics is considered somewhat effective or solely effective in a few plant species. In the present study, we tested the hypothesis that Mandevilla tenuifolia (Apocynaceae), which has floral attributes associated with psychophily, has strategies adapted to pollination by butterflies, restricting other floral visitors and making these insects act as efficient pollinators. We analysed the floral and reproductive biology of M. tenuifolia, as well as the frequency and efficiency of its flower visitors. M. tenuifolia is an herb whose flowers have strong herkogamy and secondary pollen presentation on the style head, which corresponds to 60.4% of pollen on the anthers. Flower longevity and the long period of receptivity of the stigmatic region associated with the large amount of pollen removed in the first visits suggest that flowers remain functionally female during part of anthesis. Butterflies, mainly of the families Nymphalidae and Pieridae, are the only pollinators of M. tenuifolia. Despite being self-compatible, M. tenuifolia depends on biotic vectors for fruit production. A non-significant difference in fruit set between controlled treatments and natural conditions suggests that the pollinators are efficient. The inclination resulting from the landing of butterflies on flowers, together with flower morphology, guiding the insect proboscis inside the floral tube, as well as the frequency and efficiency of butterfly visits, are evidence of the close relationship between butterflies and M. tenuifolia, and also of the efficiency of these insects as pollinators.

Use of electromyography to assess pain in the upper trapezius and lower back muscles within a fatigue protocol / Uso da eletromiografia na análise de dor dos músculos trapézio superior e lombares durante protocolo de fadiga

OBJECTIVE: The aim of this study was to investigate whether muscle fatigue indices obtained using surface electromyography and calculated in the time and frequency domains would be capable of objectively diagnosing pain and discriminating between subjects with and without pain in the upper trapezius muscle and the lower back muscles. METHODS: Forty-seven individuals underwent a muscle fatigue test for thirty-five seconds at 80% of the maximal voluntary contraction (MVC), while EMG and muscle force data were recorded. The RMS value and the median frequency (MF) were calculated within consecutive one-second windows. Linear regression analysis was used to obtain the slope coefficients and the respective y-axis intercept values, which were considered to be localized muscle fatigue indices. RESULTS: In the frequency domain, the slope coefficients were negative for both muscles, while in the time domain, the coefficient for the upper trapezius was positive and the coefficient for the lower back muscles was negative (p<0.01). Significant differences were also found in the frequency domain between subjects with and without pain in the upper trapezius (p<0.01). The subjects with pain had significantly lower force values than the subjects without pain (p<0.05), in both the upper trapezius and the lower back muscles. CONCLUSION: The force values associated with the fatigue indices (MF slope and y-axis intercept) were able to predict the presence of pain in the upper trapezius (p<0.05), but not in the lower back muscles.

OBJETIVO: A proposta do estudo foi investigar se índices de fadiga, obtidos a partir de eletromiografia de superfície, calculados no domínio do tempo e da frequência, são capazes de diagnosticar a dor objetivamente, discriminando entre sujeitos com e sem dor no trapézio superior e nos músculos lombares. MÉTODOS: Quarenta e sete indivíduos foram submetidos a um teste de fadiga muscular por 35s a 80% da contração voluntária máxima (CVM), enquanto EMG e força muscular foram registradas. O valor RMS e a mediana da frequência (MF) foram calculados em janelas consecutivas de 1s. Análise de regressão linear foi utilizada para obter os coeficientes de inclinação e seus respectivos valores de interseção no eixo y, os quais foram considerados índices de fadiga muscular localizada. RESULTADOS: Os coeficientes de inclinação analisados no domínio da frequência apresentaram comportamento similar, sendo negativos para ambos os músculos, enquanto que, no domínio tempo, o trapézio superior apresentou coeficientes positivos, e músculos lombares, coeficientes negativos (p<0,01). Diferenças significativas também foram identificadas no domínio da frequência entre os sujeitos com e sem dor no trapézio superior (p<0,01). Os indivíduos com dor apresentaram valores de força significativamente menores que os sujeitos sem dor (p<0,05), tanto nos músculos lombares quanto no trapézio superior. CONCLUSÃO: Os valores de força associados aos índices de fadiga (inclinação da MF e intersecção do eixo y) foram hábeis para predizer a presença de dor no trapézio superior (p<0,05), mas não nos músculos lombares.

Verification of protector effect of the norepinephrine and felypressin upon the cardiovascular system under action of the lidocaine hydrochloride and prilocaine hydrochloride in anesthetized rats.

Vasoconstrictor substances, as norepinephrine and epinephrine, were mixtured to local anesthetics to decrease their toxic effects and to prolong the depth of the anesthesia. However, these catecholamines produce systolic and diastolic hypertension. The effects of felypressin, a synthetic vasoconstrictor, upon arterial blood pressure and heart are lesser than those of norepinephrine or epinephrine, but due to its effects like oxytocin these catecholamines are yet the most used vasoconstrictors in association with lidocaine or another anesthetic salt. These vasoconstrictors are contraindicated for some physician, mainly for cardiac patients. But, are the catecholamines or is the salt the most dangerous components of the local anesthetic? The effects of the salt and catecholamines are opposite, but which of these exercises their effects first when inside blood vessel? Singi et al. [Pharmacol. Res. 44 (2001)] demonstrated that the first effect is always of the salt and that norepinephrine promotes protector effects upon guinea-pig isolated heart against lidocaine action. But, is this true for in vivo animals? The present study was performed with the aiming to answer this question and to verify if felypressin can induce the same effect of the norepinephrine. Fourteen Rattus norvegicus albinus, weighing 350g on average, were used. After being anesthetized with sodic thiopental, they were tracheostomizeds and one jugular and one carotid were cannuled for application of substances and to record the blood arterial pressure, respectively. The ECG was gotten through electrodes located in the front and back paws of the animals. The animals were separated in two groups, each one with seven rats. The lidocaine hydrochloride 2% in the doses of 600 microg and 3% in the doses of 900 microg acted on the cardiovascular system reducing the arterial pressure and modifying the electrocardiogram, while the prilocaine hydrochloride, in the same doses, also reduced the arterial pressure, but did not modify the electrocardiogram. When norepinephrine was associated to lidocaine 3% hydrochloride, it was possible to observe that this salt always exercised its effect first and a protective effect against the fall of pressure produced for the lidocaine. The same protective effect did not occur when felypressin was associated with prilocaine hydrochloride 3%.