Affinities of the Saw-billed Hermit (Ramphodon naevius) determined by cytochrome-b sequence data

We sequenced 912 bp of the cytochrome-b gene to examine phylogenetic relationships of the enigmatic Saw-billed Hermit (Ramphodon naevius), a large and distinctive hummingbird endemic to tropical forests of southeastern Brazil. Bootstrapped maximum parsimony and maximum likelihood analyses of sequence data from 11 hummingbirds and several outgroups (two swifts, one goatsucker) support: (a) monophyly of the traditional hermit (Phaethornithinae) and nonhermit (Trochilinae) subfamilies, (b) placement of Ramphodon among hermits, and (c) a sister relationship between Ramphodon and an exemplar of the widespread polytypic hermit genus Glaucis. The association of Ramphodon with derived hermit lineages is concordant with subfamilial patterns of wing anatomy and nest architecture. However, the unusual plumages (striped underparts) and male bills (long, serrated, hooked) shared by Ramphodon and the Tooth-billed Hummingbird (Androdon aequatorialis) appear to have evolved within separate hermit and nonhermit tooth-billed clades. Distal placement of the Ramphodon-Glaucis clade within hermits implies that even distinctive Brazilian endemics such as Ramphodon are derived forms that evolved relatively recently.

Morphometric and quantitative evaluation of the NADH-diaphorase positive myenteric neurons of the jejunum of streptozotocin-diabetic rats supplemented with acetyl-L-carnitine

In this study we investigated the effect of the acetyl-L-carnitine (ALC) supplementation on the myenteric neurons of the jejunum of rats made diabetic at the age of 105 days by streptozotocin (35 mg/kg body weight). Four groups were used: non-diabetic (C), non-diabetic supplemented with ALC (CC), diabetic (D), diabetic supplemented with ALC (DC). After 15 weeks of diabetes induction the blood was collected by cardiac puncture to evaluate glycaemia and glycated haemoglobin. Next the animals were killed and the jejunum was collected and subjected to whole-mount preparation to evidence the myenteric neurons through the histochemical technique of the NADH-diaphorase. The neuronal counts were made in 80 microscopic fields, in tissue samples of five animals of each group. The profiles of the cell bodies of 1000 neurons per group were analysed. Diabetes induced a significant increase in the area of the cell body and decrease in the number of NADH-diaphorase positive myoenteric neurons. ALC suplementation to the diabetic group promoted smaller hypertrophic effects and less neuronal loss than in the myoenteric neurons of the diabetic rats, and in addition diminished the body weight decrease and reduced the fasting glycaemia. © 2005 Blackwell Verlag.

DNA damage and nitric oxide synthesis in experimentally infected Balb/c mice with Trypanosoma cruzi

This study aimed to evaluate whether experimental Chagas disease in acute phase under benznidazole therapy can cause DNA damage in peripheral blood, liver, heart, and spleen cells or induce nitric oxide synthesis in spleen cells. Twenty Balb/c mice were distributed into four groups: control (non-infected animals); Trypanosoma cruzi infected; T. cruzi infected and submitted to benznidazole therapy; and only treated with benznidazole. The results obtained with the single cell gel (comet) assay showed that T. cruzi was able induce DNA damage in heart cells of both benznidazole treated or untreated infected mice. Similarly, T. cruzi infected animals showed an increase of DNA lesions in spleen cells. Regarding nitric oxide synthesis, statistically significant differences (p < 0.05) were observed in all experimental groups compared to negative control, the strongest effect observed in the T. cruzi infected group. Taken together, these results indicate that T. cruzi may increase the level of DNA damage in mice heart and spleen cells. Probably, nitric oxide plays an important role in DNA damaging whereas benznidazole was able to minimize induced T. cruzi genotoxic effects in spleen cells. © 2006 Elsevier Inc. All rights reserved.

The effect of eccentric strength training on heart rate and on its variability during isometric exercise in healthy older men

The purpose of this study was to investigate if chronic eccentric strength training (ST) affects heart rate (HR) and heart rate variability (HRV) during sub-maximal isometric voluntary contractions (SIVC). The training group (TG) (9 men, 62 ± 2) was submitted to ST (12 weeks, 2 days/week, 2 - 4 sets of 8-12 repetitions at 75-80% peak torque (PT). The control group (CG) (8 men, 64 ± 4) did not perform ST. The HR and the HRV (RMSSD index) were evaluated during SIVC of the knee extension (15, 30 and 40% of PT). ST increased the eccentric torque only in TG, but did not change the isometric PT and the duration of SIVC. During SIVC, the HR response pattern and the RMSSD index were similar for both groups in pre- and post-training evaluations. Although ST increased the eccentric torque in the TG, it did not generate changes in HR or HRV. © Springer-Verlag 2008.

Cellular localization of androgen synthesis in equine granulosa-theca cell tumors: Immunohistochemical expression of 17α-hydroxylase/17,20-lyase cytochrome P450

Elevated blood testosterone concentrations, often accompanied by male-typical behaviors, is a common signalment of mares with granulosa-theca cell tumors (GCTCs), but no definitive information exists regarding the cellular differentiation of tumors associated with androgen secretion. This study was conducted to localize and thereby define the cellular expression of 17α-hydroxylase/17,20-lyase cytochrome P450 (P450c17), the enzyme most directly responsible for androgen synthesis, in 30 GTCTs and control tissues (gonads and adrenal glands) using immuno-histochemistry (IHC). Immuno-reactivity for P450c17 was evident in approximately half of 30 specimens examined, was most consistent in the interstitial cells surrounding existing or developing cysts, and was less intense in cells within cysts in the smaller proportion of specimens where this was observed. In control tissues, the expression of P450c17 was localized primarily in theca interna of normal ovarian follicles, in theca-lutein cells of some corpora lutea, but not in granulosa-lutein cells. Testicular interstitial cells and islands of adreno-cortical cells located in the adrenal medulla of the adrenal cortex further established the specificity of the antisera used. These data provided the first substantive evidence that polyhedral cells identified previously in GTCTs by histopathology have the potential to synthesize and secrete androgens, similar to theca interna and theca lutein cells in normal equine ovaries. © 2010 Elsevier Inc.

Heart rate variability in healthy adolescents at rest

Objective: to describe the cardiac autonomic function in healthy adolescents between 13 and 18 years old. Methods: data from 93 adolescents, of both sexes, were analyzed; they were divided into three groups according to age. Group A 13-14 years old (n=26), Group B 15-16 years old (n = 30) and Group C 17-18 years old (n = 17). The protocol consisted of raising the heart rate, beat by beat for twenty minutes of rest in supine position with spontaneous breathing. The cardiac autonomic behavior analysis was performed by the method of heart rate variability (HRV) through the indices of the Poincaré plot (SD1, SD2 and ratio SD1/SD2) and its qualitative analysis and indices in linear time domain (RMSSD and SDNN) and frequency (LFnu, HFnu and LF/HF). One-way ANOVA test or Kruskal-Wallis test was used for comparison between groups, with a significance level of 5%. Results: there was no significant difference in none of the indices compared the three groups. In addition,visual analysis of Poincaré plot has observed for all age groups large dispersion of RR intervals, indicating that these groups have good HRV. Conclusion: there were no changes in HRV in the different age groups analyzed, however the result allowed to establish a standard for each group that was studied, becomes an important tool for comparison of cardiac autonomic function between healthy and patients subjects or in different areas.

The effects of combined aerobic and resistance training on heart rate variability in postmenopausal women

Model of the study: Controlled clinical trial. Objective: To verify the effects of 16 weeks of combined aerobic and resistance training on cardiac autonomic modulation in menopausal women. Methods: 17 menopausal women were divided into two groups: the training group (TG: n=11) and control group (CG: n=6). The body composition variables were estimated using dual-energy X-ray absorptiometry. The cardiac autonomic modulation was evaluated by heart rate variability using linear indexes. The training protocol consisted of 16 weeks of 50 minutes of resistance training and 30 minutes of aerobic training. Results: For the TG there was an increase in the rMSSD(ms) index (pre:17,4±3,7 and post:24,8±13,1, p<0,045), an increase in the duration of the intervals between the cardiac beats(ms) (pre:891,2±80,2 and post:974,1±71,4, p<0,003) and in the values of heart rate(bpm) (pre:68,1±6,4 and post:62,0±4,7, p<0,003), additionally for the spectral indexes in normalized units, changes for LF (pre:52,2±13,1 and post:44,5±12,4, p<0,025) and HF (pre:47,8±13,3 and post:55,5±12,4, p<0,025) were noticed, demonstrating increased parasympathetic and reduced sympathetic. There were no significant differences to CG. Conclusion: combined aerobic and resistance training promoted benefits to the autonomic modulation in menopausal women.

Heart failure-induced skeletal myopathy in spontaneously hypertensive rats

Background: Although skeletal muscle atrophy and changes in myosin heavy chain (MyHC) isoforms have often been observed during heart failure, their pathophysiological mechanisms are not completely defined. In this study we tested the hypothesis that skeletal muscle phenotype changes are related to myogenic regulatory factors and myostatin/follistatin expression in spontaneously hypertensive rats (SHR) with heart failure. Methods: After developing tachypnea, SHR were subjected to transthoracic echocardiogram. Pathological evidence of heart failure was assessed during euthanasia. Age-matched Wistar-Kyoto (WKY) rats were used as controls. Soleus muscle morphometry was analyzed in histological sections, and MyHC isoforms evaluated by electrophoresis. Protein levels were assessed by Western blotting. Statistical analysis: Student's t test and Pearson correlation. Results: All SHR presented right ventricular hypertrophy and seven had pleuropericardial effusion. Echocardiographic evaluation showed dilation in the left chambers and left ventricular hypertrophy with systolic and diastolic dysfunction in SHR. Soleus weight and fiber cross sectional areas were lower (WKY 3615±412; SHR 2035±224 μm2; P < 0.001), and collagen fractional volume was higher in SHR. The relative amount of type I MyHC isoform was increased in SHR. Myogenin, myostatin, and follistatin expression was lower and MRF4 levels higher in SHR. Myogenin and follistatin expression positively correlated with fiber cross sectional areas and MRF4 levels positively correlated with I MyHC isoform. Conclusion: Reduced myogenin and follistatin expression seems to participate in muscle atrophy while increased MRF4 protein levels can modulate myosin heavy chain isoform shift in skeletal muscle of spontaneously hypertensive rats with heart failure. © 2012 Elsevier B.V.

Age Affects Exercise-Induced Improvements in Heart Rate Response to Exercise

The aim of the present study was to analyze the effects of age on cardiorespiratory fitness (CRF), muscle strength and heart rate (HR) response to exercise adaptation in women in response to a long-term twice-weekly combined aerobic and resistance exercise program. 85 sedentary women, divided into young (YG; n=22, 30.3±6.2 years), early middle-aged (EMG; n=28, 44.1±2.5 years), late middle-aged (LMG; n=20, 56.7±3.5 years) and older (OG; n=15, 71.4±6.9 years) groups, had their CRF, muscle strength (1-repetition maximum test) and HR response to exercise (graded exercise test) measured before and after 12 months of combined exercise training. Exercise training improved CRF and muscle strength in all age groups (P<0.05), and no significant differences were observed between groups. Exercise training also improved resting HR and recovery HR in YG and EMG (P<0.05), but not in LMG and OG. Maximal HR did not change in any group. Combined aerobic and resistance training at a frequency of 2 days/week improves CRF and muscle strength throughout the lifespan. However, exercise-induced improvements in the HR recovery response to exercise may be impaired in late middle-aged and older women. © Georg Thieme Verlag KG.

Papel do polimorfismo da posição -786T>C do gene da sintase do óxido nítrico endotelial (eNOS) na resposta pressórica em mulheres no climatério: efeito do treinamento físico

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito de desnutrição e das citocinas pró-inflamatórias na infecção experimental em camundongos Balb/c infectados com Trypanosoma cruzi

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da atividade dos óleos essenciais de cymbopogon citratus (D.C.) Stapf, Tagetes minuta L. e Curcuma zedoaria roscoe frente aos microrganismos Candida spp., Staphylococcus spp. e Streptococcus mutans

Pós-graduação em Biopatologia Bucal - ICT

Vitamina C intra-ovo e estresse por calor na incubação de frangos de corte

Pós-graduação em Zootecnia - FCAV

Influência dos genótipos / haplótipos das posições polimórficas -786T > C, 894G > T e Íntron 4b / a do gene NOS3 sobre o sistema cardiovascular e a atividade das enzimas antioxidantes em adultos submetidos ao treinamento físico aeróbio

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)