GEANT4 tuning for pCT development

Proton beams in medical applications deal with relatively thick targets like the human head or trunk. Thus, the fidelity of proton computed tomography (pCT) simulations as a tool for proton therapy planning depends in the general case on the accuracy of results obtained for the proton interaction with thick absorbers. GEANT4 simulations of proton energy spectra after passing thick absorbers do not agree well with existing experimental data, as showed previously. Moreover, the spectra simulated for the Bethe-Bloch domain showed an unexpected sensitivity to the choice of low-energy electromagnetic models during the code execution. These observations were done with the GEANT4 version 8.2 during our simulations for pCT. This work describes in more details the simulations of the proton passage through aluminum absorbers with varied thickness. The simulations were done by modifying only the geometry in the Hadrontherapy Example, and for all available choices of the Electromagnetic Physics Models. As the most probable reasons for these effects is some specific feature in the code, or some specific implicit parameters in the GEANT4 manual, we continued our study with version 9.2 of the code. Some improvements in comparison with our previous results were obtained. The simulations were performed considering further applications for pCT development. © 2011 American Institute of Physics.

Post-ganglionic Horner's syndrome: An unusual presentation of non-Hodgkin lymphoma

In this paper, we present the rare case of a patient with cervical lymphadenopathy diagnosed as a T-cell-rich B-cell non-Hodgkin lymphoma that manifested Horner's syndrome due to a post-ganglionic sympathetic neuron lesion caused by the tumor. Copyright © 2012 S. Karger AG, Basel.

Mume clonal rootstocks for 'Aurora-1' peach in São Paulo State, Brazil

In spite of significant results achieved with scion genetic improvement in stone fruits, the peach culture in Brazil still needs studies and new technologies regarding the use of rootstocks. A wide research project has being developed at the Faculdade de Ciências Agrárias e Veterinárias (FCAV/UNESP), Jaboticabal, Brazil, dealing with the use of mume clones (Prunus mume) as rootstocks for peach trees, which has produced promising results. In this research, two mume genotypes propagated by herbaceous cuttings were tested as rootstocks for peach cultivar Aurora-1. Three different tree spacing were used: 6 x 2 m, 6 x 3 m and 6 x 4 m. The experiment was carried out at Vista Alegre do Alto (21°10'14 S, 48°37'45 W, 700 m of altitude), São Paulo State, Brazil. Growing field conditions included Hapludalfs soil with medium sandy texture and using micro sprinkler irrigation. The region has an average chilling accumulation 17.9 hours per year. The evaluations were taken in 2005 and 2006 (2nd and 3rd year after planting, respectively). The trunk diameter was evaluated every three months, from the 24th to the 41st month after planting, totalizing seven evaluations. Plants on 'Rigitano' had higher trunk diameter on the 33rd, 39th and 41st month after planting (May/06, November/06 and February/07, respectively). No significant differences were observed in the other evaluations. The diameter at 5 cm above to the graft point was larger than below, but no incompatibility symptoms were observed between rootstocks and scion. Spacing tested did not influence trunk diameter, phenology and flower bud production in 'Aurora-1' scion. In conclusion, 'Rigitano' and 'Clone 15' are recommended for high density plantings of peach 'Aurora-1' in Brazil, and the 6 x 2 m spacing can be recommended, with productivity advantages for peach under low air relative humidity and mild winter conditions. © ISHS 2012.

Hindbrain mineralocorticoid mechanisms on sodium appetite

Aldosterone acting on the brain stimulates sodium appetite and sympathetic activity by mechanisms that are still not completely clear. In the present study, we investigated the effects of chronic infusion of aldosterone and acute injection of the mineralocorticoid receptor (MR) antagonist RU 28318 into the fourth ventricle (4th V) on sodium appetite. Male Wistar rats (280-350 g) with a stainless-steel cannula in either the 4th V or lateral ventricle (LV) were used. Daily intake of 0.3 M NaCl increased to 46 ± 15 and 130 ± 6 ml/24 h after 6 days of infusion of 10 and 100 ng/h of aldosterone into the 4th V (intake with vehicle infusion: 2 ± 1 ml/24 h). Water intake fell slightly and not consistently, and food intake was not affected by aldosterone. Sodium appetite induced by diuretic (furosemide) combined with 24 h of a low-sodium diet fell from 12 ± 1.7 ml/2 h to 5.6 ± 0.8 ml/2 h after injection of the MR antagonist RU 28318 (100 ng/2 μl) into the 4th V. RU 28318 also reduced the intake of 0.3 M NaCl induced by 9 days of a low-sodium diet from 9.5 ± 2.6 ml/2 h to 1.2 ± 0.6 ml/2 h. Infusion of 100 or 500 ng/h of aldosterone into the LV did not affect daily intake of 0.3 M NaCl. The results are functional evidence that aldosterone acting on MR in the hindbrain activates a powerful mechanism involved in the control of sodium appetite. © 2013 the American Physiological Society.

Association between energy cost of walking, muscle activation, and biomechanical parameters in older female fallers and non-fallers

Objective: To determine the nervous activation, muscle strength, and biomechanical parameters that influence the cost of walking in older fallers and non-fallers. Methods: Maximal voluntary isokinetic torque was measured for the hip, knee and ankle of older women. Oxygen consumption was measured at rest and during 8 min of walking at self-selected speed. An additional minute of walking was performed to collect kinematic variables and the electromyographic signal of trunk, hip, knee, and ankle muscles, which was analyzed by the linear envelope. Cost of walking was calculated by subtracting resting body mass-normalized oxygen consumption from walking body mass-normalized oxygen consumption. Stride time and length, and ankle and hip range of motion were calculated from kinematic data. Findings: Older adult fallers had 28% lower knee extensor strength (p = 0.02), 47% lower internal oblique activation at heel contact (p = 0.03), and higher coactivation between tibialis anterior and gastrocnemius lateralis in each of the gait phases (p < 0.05). For fallers, a higher activation of gluteus maximus was associated with a higher cost of walking (r = 0.55, p < 0.05 and r = 0.71, p < 0.01, before and after heel contact, respectively). For non-fallers, an association between cost of walking and age (r = 0.60, p = 0.01) and cost of walking and thigh muscle coactivation (r = 0.53, p = 0.01) existed. Interpretation: This study demonstrated that there may be links between lower-extremity muscle weakness, muscle activation patterns, altered gait, and increased cost of walking in older fallers. © 2013 Elsevier Ltd. All rights reserved.

Sidestream cigarette smoke and cardiac autonomic regulation

Background: The literature has already demonstrated that cigarette influences the cardiovascular system. In this study, we performed a literature review in order to investigate the relationship between sidestream cigarette smoke (SSCS) and cardiac autonomic regulation. Methods. Searches were performed on Medline, SciELO, Lilacs and Cochrane databases using the crossing between the key-words: cigarette smoking, autonomic nervous system, air pollution and heart rate variability. Results: The selected studies indicated that SSCS exposure affects the sympathetic and parasympathetic responses to changes in arterial blood pressure. Moreover, heart rate responses to environmental tobacco smoke are increased in smokers compared to non-smokers. The mechanism involved on this process suggest increased oxidative stress in brainstem areas that regulate the cardiovascular system. Conclusion: Further studies are necessary to add new elements in the literature to improve new therapies to treat cardiovascular disorders in subjects exposed to sidestream cigarette smoke. © 2013 Valenti et al; licensee BioMed Central Ltd.

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.

Relationship between cardiac autonomic regulation and auditory mechanisms: Importance for growth and development

The literature has already demonstrated that auditory stimulation with music influences the cardiovascular system. In this study, we performed a literature review in order to investigate the relationship between auditory mechanisms and cardiac autonomic regulation. The selected studies indicated that there is a strong correlation between noise intensity and vagal-sympathetic balance. Also, it was reported that music therapy improved heart rate variability in anthracycline-treated breast cancer patients. It was hypothesized that dopamine release in the striatal system induced by pleasure songs are involved in the cardiac autonomic regulation. Further studies are necessary to add new elements in the literature to improve new therapies to treat cardiovascular disorders.

Simulation-based cutaneous surgical-skill training on a chicken-skin bench model in a medical undergraduate program

Background: Because of ethical and medico-legal aspects involved in the training of cutaneous surgical skills on living patients, human cadavers and living animals, it is necessary the search for alternative and effective forms of training simulation. Aims: To propose and describe an alternative methodology for teaching and learning the principles of cutaneous surgery in a medical undergraduate program by using a chicken-skin bench model. Materials and Methods: One instructor for every four students, teaching materials on cutaneous surgical skills, chicken trunks, wings, or thighs, a rigid platform support, needled threads, needle holders, surgical blades with scalpel handles, rat-tooth tweezers, scissors, and marking pens were necessary for training simulation. Results: A proposal for simulation-based training on incision, suture, biopsy, and on reconstruction techniques using a chicken-skin bench model distributed in several sessions and with increasing levels of difficultywas structured. Both feedback and objective evaluations always directed to individual students were also outlined. Conclusion: The teaching of a methodology for the principles of cutaneous surgery using a chicken-skin bench model versatile, portable, easy to assemble, and inexpensive is an alternative and complementary option to the armamentarium of methods based on other bench models described. © Indian Journal of Dermatology 2013.

Associação entre fatores de risco cardiovascular e capacidade funcional de idosos longevos

Study design: cross-sectional study. Objective: To assess the association between the presence of cardiovascular risk factor (CRP) and functional capacity of the oldest old. Methods: The sample 9onsisted of 91 elderly aged 80 and 90 years (83.0 ± 2.5 years) with 60 women (82.2 ± 2.1 years) and 31 men (83.2 ± 2,6 years) residing in the city of Presidente Prudente - SP. The FRC were analyzed: arterial hypertension (AH) and excess body fat (total and trunk). The presence of hypertension was verified by means of self-reported questionnaire based on the Standard Health Questionnaire (SHQ). Assessment of body was made by absorpiometria dual energy X-ray absorptiometry (DXA) and functional capacity was assessed by the functional tests (static balance, normal walking speed and force of the lower limbs). For statistical analysis we carried out the chi-square test, the software used was SPSS (13.0) and the significance level was set at 5%. Results. In males, with hypertension and the presence of excess %BF had lower performance in the lower limbs (83.3% lower and 16.7% higher), p = 0.011 compared to those with only a VCF. The elderly women with hypertension and the presence of excess GTron% also had lower performance on the same test (80.6% lower and 19.4% higher), p = 0.018 and the test of walking speed (80.6% lower and 19.4% higher), p = 0.034. Conclusion: Arterial hypertension and excess body fat (total and trunk) aggregated are FRC, which are associated with reduced functional capacity of the oldest old.

Efeito de um protocolo de treinamento concorrente sobre fatores de risco para o acúmulo de gordura hepática de adolescentes obesos

Study Design: Prospective study Objective: To evaluate the effect of a protocol of concurrent training lasting 16 weeks on risk factors for the accumulation of hepatic fat in obese youth. Methods: 38 obese children and adolescents of both sexes, between 12 and 15 years old. The obesity was attested by the percentage of body fat, which was estimated by dual-energy X-ray absorptiometry (DEXA). Additionally, the amount of fat located in the trunk (kg) was estimated too. Before and after the intervention, the youths underwent biochemical blood tests (fasting complete lipid profile [mg / dL]) and ultrasonography of the liver (right size Wolves [LD cm] and left [LE in cm]). The intervention consisted of concurrent training (strength training [30 minutes] and endurance training [30 minutes]) with three sessions per week, totaling 180 minutes a week, for ten weeks. Statistical analysis was made by the test t of Student for paired data using SPSS software (17.0) and significance statistical fixed at p <5%. Results: After the intervention, significant improvements were observed in the percentage of total fat (PRE: 45.1 ± 5.3 and POST: 41.7 ± 5.6, p = 0.001) and in the trunk region (PRE: 46, 5 ± 5.6 and POST: 42.9 ± 6.3, p = 0.001). For lipid profile, reduction in total cholesterol (PRE: 164 ± 34 and POST: 148 ± 29, p = 0.001), triglycerides (PRE: 118 ± 59 and POST: 104 ± 53, p = 0.002) and lipoproteins density (PRE: 100 ± 29 and POST: 85 ± 26, p = 0.001), but not for high-density (p = 0.981). Both the LE (PRE: 8.8 ± 1.4 and POST: 7.8 ± 1.3, p = 0.001) and LD (PRE: 13.6 ± 1.3 and POST: 12.9 ± 1, 1, p = 0.001) experienced a decrease in its proportions. Conclusion: The concurrent training was effective in combating some risk factors to the accumulation of fat in the liver, as well as in reducing fat in both lobes of the organ in young obese.

Role of brain nitric oxide in the cardiovascular control of bullfrogs

The goal of the present study was to determine if nitric oxide (NO) acting on the brain of bullfrog (Lithobates catesbeianus) is involved in arterial pressure and heart rate (HR) control by influencing sympathetic activity. We investigated the effect of intracerebroventricular injections of l-NMMA (a nonselective NO synthase inhibitor) on mean arterial blood pressure (MAP), HR and cutaneous vascular conductance (CVC) of pelvic skin after intravenous injection of α or β adrenergic blockers, prazosin or sotalol, respectively. Arterial pressure was directly measured by a telemetry sensor inserted in the aortic arch of animals. l-NMMA increased MAP, but did not change HR. This hypertensive response was inhibited by the pre-treatment with prazosin, but accentuated by sotalol. The effect of l-NMMA on MAP was also inhibited by i.v. injections of the ganglionic blocker, hexamethonium. Thus, NO acting on the brain of bullfrog seems to present a hypotensive effect influencing the sympathetic activity dependent on α and β adrenergic receptors in the periphery. © 2013 Elsevier Inc.

Slimmer or Fertile? Pharmacological Mechanisms Involved in Reduced Sperm Quality and Fertility in Rats Exposed to the Anorexigen Sibutramine

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

Time-course of neuroendocrine changes and its correlation with hypertension induced by ethanol consumption

Ethanol (ETOH) consumption has been associated with endocrine and autonomic changes, including the development of hypertension. However, the sequence of pathophysiological events underlying the emergence of this effect is poorly understood. Aims: This study aimed to establish a time-course correlation between neuroendocrine and cardiovascular changes contributing to the development of hypertension following ETOH consumption. Methods: Male adult Wistar rats were subjected to the intake of increasing ETOH concentrations in their drinking water (first week: 5%, second week: 10%, third and fourth weeks: 20% v/v). Results: ETOH consumption decreased plasma and urinary volumes, as well as body weight and fluid intake. Furthermore, plasma osmolality, plasma sodium and urinary osmolality were elevated in the ETOH-treated rats. ETOH intake also induced a progressive increase in the mean arterial pressure (MAP), without affecting heart rate. Initially, this increasein MAP was correlated with increased plasma concentrations of adrenaline and noradrenaline. After the second week of ETOH treatment, plasma catecholamines returned to basal levels, and incremental increases were observed in plasma concentrations of vasopressin (AVP) and angiotensin II (ANG II). Conversely, plasma oxytocin, atrial natriuretic peptide, prolactin and the hypothalamus-pituitary-adrenal axis components were not significantly altered by ETOH. Conclusions: Taken together, these results suggest that increased sympathetic activity may contribute to the early increase in MAP observed inETOHtreated rats. However, the maintenance of this effect may be predominantly regulated by the long-term increase in the secretion of other circulating factors, such as AVP and ANG II, the secretion of both hormones being stimulated by the ETOH-induced dehydration. © The Author 2013. Medical Council on Alcohol and Oxford University Press. All rights reserved.