Neurotoxic action of permethrin in Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) female ticks. Morphological and cytochemical evaluation of the central nervous system

Studies on the molecular bases of the neurotoxic action of acaricides are found in the literature; but there are no studies of this action on the nervous system of ticks at the cellular level. The present study describes the morphological and cytochemical changes in the synganglion of Rhipicephalus sanguineus semi-engorged females exposed to different concentrations of permethrin, a pyrethroid with recognized neurotoxic action. Permethrin induced the degeneration of the synganglion through a process of apoptosis involving autophagy, characterized by the condensation and margination of the chromatin, formation of blebs in the nuclear envelope and fragmentation of the nucleus, loss of shape of neural cells and integrity of cellular membrane, cytoplasmic shrinkage, and lower levels of acid phosphatase in the nervous tissue as the concentration of permethrin increased. This study provided further evidence of the neurotoxic action of permethrin, which impairs the metabolism of R. sanguineus nervous systems, and consequently the physiology of other systems, dependent on the neural control. These results provide cytochemical and histological confirmation of the neurotoxic action of permethrin, previously inferred from molecular and tick behavioral evidence. © 2013 Elsevier B.V.

The influence of resistance exercise with emphasis on specific contractions (concentric vs. eccentric) on muscle strength and post-exercise autonomic modulation: a randomized clinical trial

Contextualização:Ações concêntricas apresentam maior estresse cardiovascular quando comparadas às excêntricas. Entretanto, não se sabe a influência desses tipos de ações no comportamento da modulação autonômica cardíaca durante o processo de recuperação pós-esforço.Objetivo:Comparar o efeito de um treinamento resistido para o grupo extensor do joelho realizado com ênfase concêntrica vs excêntrica sobre a força muscular e a recuperação pós-exercício considerando índices de variabilidade de frequência cardíaca (VFC) em jovens saudáveis.Método:Cento e cinco homens, com idades entre 18 e 30 anos, foram randomizados em quatro grupos: controle concêntrico (CCONC), controle excêntrico (CEXC), treinamento concêntrico (TCONC) e treinamento excêntrico (TEXC). Os grupos CCONC e CEXC realizaram uma sessão de exercício reduzido (ER) para o grupo extensor do joelho [três séries de uma repetição a 100% de uma repetição máxima (1RM)], e os grupos TCONC e TEXC realizaram dez sessões de treinamento. A VFC foi analisada no momento basal e na recuperação após as sessões (T1, T2, T3 e T4).Resultados:Observou-se aumento da força muscular para o grupo TEXC. Em relação à modulação autonômica cardíaca, observou-se, em comparação ao momento basal, aumento dos índices SDNN e SD2 no momento T1 nos grupos CCONC e CEXC e aumento dos índices RMSSD, SD1 e AF (ms2) nos momentos T1, T2 e T4 no grupo TEXC.Conclusões:Conclui-se que o treinamento resistido realizado com ênfase em contrações excêntricas promoveu ganho de força e aumento da modulação vagal cardíaca durante o processo de recuperação em relação à condição basal.

Effects of an isotonic beverage on autonomic regulation during and after exercise

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

The phylogeny and ontogeny of autonomic control of the heart and cardiorespiratory interactions in vertebrates

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of Pursed-Lip Breathing in Patients With COPD: Linear and Nonlinear Analysis of Cardiac Autonomic Modulation

Objective: The aim of the present study was to evaluate the effect of pursed-lip breathing (PLB) on cardiac autonomic modulation in individuals with chronic obstructive pulmonary disease (COPD) while at rest. Methods: Thirty-two individuals were allocated to one of two groups: COPD (n = 17; 67.29 +/- 6.87 years of age) and control (n = 15; 63.2 +/- 7.96 years of age). The groups were submitted to a two-stage experimental protocol. The first stage consisted of the characterization of the sample and spirometry. The second stage comprised the analysis of cardiac autonomic modulation through the recording of R-R intervals. This analysis was performed using both nonlinear and linear heart rate variability (HRV). In the statistical analysis, the level of significance was set to 5% (p = 0.05). Results: PLB promoted significant increases in the SD1, SD2, RMSSD and LF (ms(2)) indices as well as an increase in alpha(1) and a reduction in alpha(2) in the COPD group. A greater dispersion of points on the Poincare plots was also observed. The magnitude of the changes produced by PLB differed between groups. Conclusion: PLB led to a loss of fractal correlation properties of heart rate in the direction of linearity in patients with COPD as well as an increase in vagal activity and impact on the spectral analysis. The difference in the magnitude of the changes produced by PLB between groups may be related to the presence of the disease and alterations in the respiration rate.

Analysis of cardiac autonomic modulation of children with attention deficit hyperactivity disorder

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

Autonomic modulation and its relation with body composition in swimmers

This study compared autonomic modulation in swimmers and non-athletes in relation to body composition. A total of 28 athletes with a mean age of 19.7 +/- 2.9 years were evaluated who had at least 2 years of swimming training, trained approximately 7,000 m per day, with a frequency of 5 days per week, and who competed at national level. The control group was made up of 21 volunteers (23.0 +/- 2.5 years), who did not practice regular physical activity (<2 hours per week). Body composition was estimated using dual-energy x-ray absorptiometry, and autonomic modulation was assessed by heart rate variability (HRV). The results show that there were significant differences in autonomic modulation and body composition between the groups, and that the athletes had a higher overall variability (standard deviation of all normal intervals between consecutive heart beats [SDNN]: 78.1 [72.5-93.5] x 61.1 [56.4-75.7], p = 0.022) and greater autonomic balance (LF/HF: 0.96 [0.88-1.35] x 0.71 [0.56-0.93], p = 0.023), compared with the non-athletes, respectively. In addition, a moderate and positive relation was obtained between fat-free mass and the square root of the squared differences between consecutive heartbeat intervals (RMSSD: r = 0.526, p = 0.004 x r = 0.456, p = 0.038), (SDNN: r = 0.617, p = 0.001 x r = 0.571, p = 0.007) and low frequency (LFms(2): r = 0.517, p = 0.005 3 r = 0.600, p = 0.004) in the athletes and non-athletes, respectively, without a correlation between fat mass (FM). The conclusion is that young highly trained swimmers had lower FM, increased fat-free mass, and better HRV than young adult non-athletes and suggests that a lower quantity of FM and, especially, a greater fat-free mass (FFM) are linked to better autonomic modulation. Thus, this study could contribute to coaches and trainers establishing greater performance by better autonomic modulation and greater quantity of FFM.

Spirituality/religiosity and cardiovascular system

Introduction: Spirituality/religiosity is associated to well-being. In this article, we describe the association between spirituality/religiosity and cardiovascular system. Materials and methods: We performed searches using Medline, SciELO, Lilacs and Cochrane databases using crossing between the keywords “spirituality,” “cardiovascular system,” “parasympathetic nervous system,” and “sympathetic nervous system.”Results: The electronic search yielded 65 references by crossing the terms “spirituality” and “cardiovascular system.” Among these, the first round of elimination resulted in exclusion of 55 titles and abstracts that were not clearly related to the subject of the review. The titles of the remaining 10 abstracts were submitted to a final evaluation that accounted for the inclusion criteria. An investigation into the reference lists confirmed the absence of relevant documents. Summaries of the analysed studies were selected. Discussion: Among 10 studies selected, 8 of them indicated that spirituality/religiosity is very important for the cardiovascular system, whereas only 2 found no significant association between the two variables in women. Conclusion: We suggest that spirituality/religiosity is an alternative and non-pharmacological therapy for cardiovascular disorders.

Association between central auditory processing mechanism and cardiac autonomic regulation

Background: This study was conducted to describe the association between central auditory processing mechanism and the cardiac autonomic regulation. Methods: It was researched papers on the topic addressed in this study considering the following data bases: Medline, Pubmed, Lilacs, Scopus and Cochrane. The key words were: “auditory stimulation, heart rate, autonomic nervous system and P300”. Results: The findings in the literature demonstrated that auditory stimulation influences the autonomic nervous system and has been used in conjunction with other methods. It is considered a promising step in the investigation of therapeutic procedures for rehabilitation and quality of life of several pathologies. Conclusion: The association between auditory stimulation and the level of the cardiac autonomic nervous system has received significant contributions in relation to musical stimuli.

A single bout of exercise with a flexible pole induces significant cardiac autonomic responses in healthy men

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

Autonomic control of post-air-breathing tachycardia in Clarias gariepinus

The African catfish (Clarias gariepinus) is a teleost with bimodal respiration that utilizes a paired suprabranchial chamber located in the gill cavity as an air-breathing organ. Like all air-breathing fishes studied to date, the African catfish exhibits pronounced changes in heart rate (f H) that are associated with air-breathing events. We acquired f H, gill-breathing frequency (f G) and air-breathing frequency (f AB) in situations that require or do not require air breathing (during normoxia and hypoxia), and we assessed the autonomic control of post-air-breathing tachycardia using an infusion of the β-adrenergic antagonist propranolol and the muscarinic cholinergic antagonist atropine. During normoxia, C. gariepinus presented low f AB (1.85 ± 0.73 AB h−1) and a constant f G (43.16 ± 1.74 breaths min−1). During non-critical hypoxia (PO2 = 60 mmHg), f AB in the African catfish increased to 5.42 ± 1.19 AB h−1 and f G decreased to 39.12 ± 1.58 breaths min−1. During critical hypoxia (PO2 = 20 mmHg), f AB increased to 7.4 ± 1.39 AB h−1 and f G decreased to 34.97 ± 1.78 breaths min−1. These results were expected for a facultative air breather. Each air breath (AB) was followed by a brief but significant tachycardia, which in the critical hypoxia trials, reached a maximum of 143 % of the pre-AB f H values of untreated animals. Pharmacological blockade allowed the calculation of cardiac autonomic tones, which showed that post-AB tachycardia is predominantly regulated by the parasympathetic subdivision of the autonomic nervous system.

Histopathological, immunohistochemical, and molecular study of BHV-5 infection in the central nervous system of experimentally infected calves

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

Pyridinic analog of the natural product (-)-spectaline as potential adjuvant for the treatment of central nervous system disorders

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

Response of cardiac autonomic modulation after a single exposure to musical auditory stimulation

The acute effects after exposure to different styles of music on cardiac autonomic modulation assessed through heart rate variability (HRV) analysis have not yet been well elucidated. We aimed to investigate the recovery response of cardiac autonomic modulation in women after exposure to musical auditory stimulation of different styles. The study was conducted on 30 healthy women aged between 18 years and 30 years. We did not include subjects having previous experience with musical instruments and those who had an affinity for music styles. The volunteers remained at rest for 10 min and were exposed to classical baroque (64-84 dB) and heavy metal (75-84 dB) music for 10 min, and their HRV was evaluated for 30 min after music cessation. We analyzed the following HRV indices: Standard deviation of normal-to-normal (SDNN) intervals, root mean square of successive differences (RMSSD), percentage of normal-to-normal 50 (pNN50), low frequency (LF), high frequency (HF), and LF/HF ratio. SDNN, LF in absolute units (ms (2) ) and normalized (nu), and LF/HF ratio increased while HF index (nu) decreased after exposure to classical baroque music. Regarding the heavy metal music style, it was observed that there were increases in SDNN, RMSSD, pNN50, and LF (ms (2) ) after the musical stimulation. In conclusion, the recovery response of cardiac autonomic modulation after exposure to auditory stimulation with music featured an increased global activity of both systems for the two musical styles, with a cardiac sympathetic modulation for classical baroque music and a cardiac vagal tone for the heavy metal style.

Cardiac autonomic modulation of children with down syndrome

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