No abstract

Background: The effect of home-based exercise training on neurovascular control in heart failure patients is unknown. Aims: To test the hypothesis that home-based training would maintain the reduction in muscle sympathetic nerve activity (MSNA) and forearm vascular resistance (FVR) acquired after supervised training. Methods and results: Twenty-nine patients (54 T 1.9 years, EF < 40%) were randomised into two groups: untrained control (n = 12) and exercise trained (n = 17). Both groups underwent assessment of Quality of Life (QoL), MSNA, and forearm blood flow. The exercise group underwent a 4-month supervised training program followed by 4 months of home-based training. After the initial 4 months of training, patients in the exercise group showed a significant increase in peak VO 2 and reduction in MSNA, compared to the untrained group, but this was not maintained during 4 months of home-based training. In contrast, the decrease in FVR (56 T 3 vs. 46 T 4 vs. 40 T 2 U, p = 0.008) and the improvement in QOL that were achieved during supervised training were maintained during home-based training. Conclusions: Home-based training following supervised training is a safe strategy to maintain improvements in QoL and reduction in FVR in chronic heart failure patients, but is an inadequate strategy to maintain fitness as estimated by peak VO 2 or reduction in neurohumoral activation.

We hypothesized that the muscle vasodilatation during mental stress and exercise would vary among humans who are polymorphic at alleles 16 and 27 of the β2-adrenoceptors. From 216 preselected volunteers, we studied 64 healthy, middle-aged normotensive women selected to represent three genotypes: homozygous for the alleles Arg16 and Gln27 (Arg16/Gln27, n = 34), Gly16 and Gln27 (Gly16/Gln27, n = 20), and Gly16 and Glu27 (Gly16/Glu27, n = 10). Forearm blood flow (plethysmography) and muscle sympathetic nerve activity (microneurography) were recorded during 3-min Stroop color-word test and 3-min handgrip isometric exercise (30% maximal voluntary contraction). Baseline muscle sympathetic nerve activity, forearm vascular conductance, mean blood pressure, and heart rate were not different among groups. During mental stress, the peak forearm vascular conductance responses were greater in Gly16/Glu27 group than in Gly16/Gln27 and Arg16/Gln27 groups (1.79 ± 0.66 vs. 0.70 ± 0.11 and 0.58 ± 0.12 units, P = 0.03). Similar results were found during exercise (0.80 ± 0.25 vs. 0.28 ± 0.08 and 0.31 ± 0.08 units, P = 0.02). Further analysis in a subset of subjects showed that brachial intra-arterial propranolol infusion abolished the difference in vasodilatory response between Gly16/Glu27 ( n = 6) and Arg16/Gln27 ( n = 7) groups during mental stress (0.33 ± 0.20 vs. 0.46 ± 0.21 units, P = 0.50) and exercise (0.08 ± 0.06 vs. 0.03 ± 0.03 units, P = 0.21). Plasma epinephrine concentration in Arg16/Gln27 and Gly16/Glu27 groups was similar. In conclusion, women who are homozygous for Gly16/Glu27 of the β2-adrenoceptors have augmented muscle vasodilatory responsiveness to mental stress and exercise.

The structural elements, tridimensional aspects of the lingual papillae, yours connective tissue cores (CTCs) and the ultrastructure of the dorsal epithelium surface of the tongue of guinea pig are examined. Filiform papillae and their CTCs lie throughout the tongue surface, featuring subtypes and different shapes. Fungiform papillae are dome-shaped, and their CTCs are few, with heterogenic disposition among the filiform papillae in the lingual apex and body and in grooves stretching to the side margin among the foliate papillae towards the lingual apex. Foliate papillae are well developed, and their CTCs are composed of five pairs of parallel seams limited by deep grooves placed bilaterally in the caudal region. Two vallate papillae are observed in the caudal region and reveal specialized structures which are developed and differentiated when they present compound elements by a double epithelial projection, in a column, similar to the shape of the foliate papilla. Further, the epithelium is organized by layers with ultrastructural components. Therefore, we conclude that the structural descriptions, dimensional aspects of tongue papillae, their CTCs and the ultrastructure of the tongue epithelium of guinea pigs are similar to other rodent mammals, however, with new descriptions as double epithelial projection constituting each vallate papilla.

ResumoO quati é um animal que pertence ao Filo Chordata, à Classe Mammalia, à Ordem Carnívora e à Família Procyonidae. A característica marcante da família Procyonidae é a presença de cinco dígitos em seus membros: WRUiFLFR H SpOYLFR (VWHV DQLPDLV VmR FODVVL¿FDGRV FRPR SODQWtJUDGRV H SRGHP UHDOL]DU PRYLPHQWRV PDQXDLV em diferentes direções. Possui hábitos de subir em árvores para procriar, fugir do perigo e pernoitar.

Although the vasodilatory response during mental stress is blunted in heart failure (HF), the mechanisms underlying this phenomenon are not fully understood. We tested the hypothesis that sympathetic activity limits the endothelium-dependent vasodilatation during mental stress in chronic HF patients. Twenty-one HF patients (age 45 +/- 2 yr, functional classes III and IV, New York Heart Association) and 22 age-matched normal controls (NC; age 42 +/- 2 yr, P = 0.13) were studied at rest and during 4 min of Stroop color-word test with brachial intra-arterial saline, acetylcholine (endothelium dependent), phentolamine (alpha-blocker), and phentolamine plus acetylcholine infusion. Forearm blood flow was measured by venous occlusion plethysmography. Baseline forearm vascular conductance (FVC) was significantly lower in HF patients (2.18 +/- 0.12 vs. 3.66 +/- 0.22 units, P = 0.001). During mental stress with saline, the changes in FVC were significantly blunted in HF patients compared with NC (0.92 +/- 0.20 vs. 2.13 +/- 0.39 units, P = 0.001). In HF, the vasodilatation with acetylcholine was similar to saline control and significantly lower than in NC. In HF patients, phentolamine significantly increased FVC responses (1.16 +/- 0.20 vs. 2.09 +/- 0.29 units, P = 0.001), and the difference between HF patients and NC tended to decrease (2.09 +/- 0.29 vs. 3.61 +/- 0.74 units, P = 0.052). The vasodilatation with phentolamine plus acetylcholine was similar between HF and NC (4.23 +/- 0.73 vs. 4.76 +/- 1.03 units, P = 0.84). In conclusion, sympathetic activation mediates the blunted muscle endothelium-mediated vasodilatation during mental stress in HF patients.

RESUMO.-[Caracterização do ciclo estral de Galea spixii (Wagler, 1831).]Os Galea spixii habitam a vegetação semiá-rida da Caatinga, no Nordeste brasileiro. Eles são criados em cativeiro para realização de pesquisas relacionadas a biologia da reprodução. Sendo assim, o objetivo deste trabalho foi caracterizar o ciclo estral de G. spixii para obtenção de informações que melhorem o conhecimento do manejo reprodutivo da espécie em cativeiro. O ciclo estral foi monitorado por citologia esfoliativa vaginal em doze fêmeas adultas. Após a detecção de dois ciclos completos em cada animal, os mesmos foram eutanasiados. Em seguida foi realizado estudo histológico do epitélio vaginal com três fêmeas em cada fase do ciclo estral; cinco foram pareadas com machos para realização do grupo controle e outras três fêmeas foram utilizadas para monitorar a formação e ruptura da membrana de oclusão vaginal. Através de citologia esfoliativa vaginal, constatou-se predomínio de células superficiais em estro, células intermediárias grandes em proestro, células intermediárias pequenas e células parabasais com presença de neutrófilos em diestro e metaestro, respectivamente. O es- The Galea spixii inhabits semiarid vegetation of Caatinga in the Brazilian Northeast. They are bred in captivity for the development of researches on the biology of reproduction. Therefore, the aim of this study is characterize the estrous cycle of G. spixii, in order to provide information to a better knowledge of captive breeding of the species. The estrous cycle was monitored by vaginal exfoliative cytology in 12 adult females. After the detection of two complete cycles in each animal, the same were euthanized. Then, histological study of the vaginal epithelium, with three females in each phase of the estrous cycle was performed; five were paired with males for performing the control group for estrous cycle phases, and three other were used to monitor the formation and rupture of vaginal closure membrane. By vaginal exfoliative cytology, predominance of superficial cells in estrus, large intermediate cells in proestrus, intermediate and parabasal cells, with neutrophils, in diestrus and metestrus respectively was found. Estrus was detected by the presence of spermatozoa in the control group. By histology, greater proliferation of the vaginal epithelium in proestrus was observed. We conclude that the estrous cycle of G. spixii lasts 15.8 ± 1.4 days and that the vaginal closure membrane develops until complete occlusion of the vaginal ostium, breaking after few days. Future studies may reveal the importance of this fact for the reproductive success of this animal. INDEX TERMS: Galea spixii, cavies, female, preservation, reproduction, rodents. Characterization of the estrous cycle in

The blunted reflex muscle vasodilatory response during exercise in advanced HF patients is, at least in part, due to the increase in sympathetic nerve activity.