Moderate physical activity when performed on a regular basis presents a number of benefits to the whole organism, especially regarding immune system function, such as augmenting resistance to infections and to cancer growth. Although glutamine production by active muscle cells as well as neuroendocrine alterations mediated by the chronic adaptation to exercise may play a role, the entire mechanism by which exercise makes the immune system aware of challenges remains mostly uncovered. This is particularly true for the effects of an acute exercise session on immune function. In this work, circulating monocytes/macrophages from sedentary rats submitted to an acute (1 h) swimming session were tested for the ability of phagocytosing zymosan particles, phorbol miristate acetate (PMA)-induced hydrogen peroxide production, nitric oxide (NO) release (assessed by nitrate and nitrite production) and the expression of NO synthases (NOS-1, NOS-2 and NOS-3). The results showed that an exercise bout induced a 2.4-fold rise in macrophage phagocytic capacity (p ¼ 0.0041), a 9.6-fold elevation in PMA-induced hydrogen peroxide release into the incubation media (1-h, p ¼ 0.0022) and a 95.5%-augmentation in nitrite basal production (1-h incubation; p ¼ 0.0220), which was associated with a marked expression of NOS-2 (the inducible NOS isoform; p ¼ 0.0319), but not in other NOS gene products. Although NOS-2 expression is nuclear factor-kB (NF-kB)-dependent, no systemic oxidative stress was found, as inferred from the data of plasma TBARS and glutathione disulphide (GSSG) to glutathione (GSH) ratio in circulating blood erythrocytes which remained constant after the acute exercise. Also, no stressful situation seemed to be faced by monocytes/macrophages, since the expression of the 70-kDa heat shock protein (HSP70) remained unchanged. We conclude that NF-kB-dependent induction of NOS-2 and macrophage activation must be related to local factor(s) produced in the surroundings of monocytes/macrophages.
Striated muscle activity is always accompanied by oxidative stress (OxStress): the more intense muscle work and/or its duration, the more a redox imbalance may be attained. In spite of cardiac muscle functioning continuously, it is well known that the heart does not suffer from OxStress-induced damage over a broad physiological range. Although the expression of antioxidant enzymes may be of importance in defending heart muscle against OxStress, a series of combined antioxidant therapeutic approaches have proved to be mostly ineffective in avoiding cellular injury. Hence, additional mechanisms may be involved in heart cytoprotection other than antioxidant enzyme activities. The strong cardiotoxic effect of doxorubicin-induced cancer chemotherapy shed light on the possible role for multidrug resistance-associated proteins (MRP) in this context. Muscle activity-induced 'physiological' OxStress enhances the production of glutathione disulfide (GSSG) thus increasing the ratio of GSSG to glutathione (GSH) content inside the cells, which, in turn, leads to redox imbalance. Since MRP1 gene product (a GS-X pump ATPase) is a physiological GSSG transporter, adult Wistar rats were tested for MRP1 expression and activity in the heart and skeletal muscle (gastrocnemius), in as much as the latter is known to be extremely sensitive to muscle activity-induced OxS. MRP1 expression was completely absent in skeletal muscle. In contrast, the heart showed an exercise training-dependent induction of MRP1 protein expression which was further augmented (2.4-fold) as trained rats were challenged with a session of acute exercise. On the other hand, inducible expression of the 70-kDa heat shock protein (HSP70), a universal marker of cellular stress, was completely absent in the heart of sedentary and acutely exercised rats, whereas skeletal muscle showed a conspicuous exercise-dependent HSP70 expression, which decreased by 45% with exercise training. This effect was paralleled by a 58% decrease in GSH content in skeletal muscle which was even higher (an 80%-fall) after training thus leading to a marked redox imbalance ([GSSG]/[GSH] raised up to 38-fold). In the heart, GSH contents and [GSSG]/[GSH] ratio remained virtually unchanged even after exercise challenges, while GS-X pump activity was found to be 20% higher in the heart related to skeletal muscle. These findings suggest that an intrinsic higher capacity to express the MRP1/GS-X pump may dictate the redox status in the heart muscle thus protecting myocardium by preventing GSSG accumulation in cardiomyocytes as compared to skeletal muscle fibres.
The purpose of this study was to determine the validity of using the electromyography (EMG) signal as a noninvasive method of estimating the lactate threshold (LT) power output in recreational cyclists. Using an electromagnetic bicycle ergometer and constant pedaling cadence of 80 rpm, 24 recreational cyclists performed an incremental exercise protocol that consisted of stepwise increases in power output of 25 W every 3 min until exhaustion. The EMG signal was recorded from the right vastus lateralis (VL) and right rectus femoris (RF) throughout the test. Blood samples were taken from the fingertip every 3 min. The LT was determined by examining the relation between the lactate concentration and the power output using a log-log transformation model. The root mean square (RMS) value from the EMG signal was calculated for every 1-second non-superimposing window. Sets of pairs of straight regression lines were plotted and the corresponding determination coefficients (R(2)) were calculated. The intersection point of the pair of lines with the highest R(2) product was chosen to represent the EMG threshold (EMGT). The results showed that the correlation coefficients (r) between EMGT and LT were significant (p < 0.01) and high for the VL (r = 0.826) and RF (r = 0.872). The RF and VL muscles showed similar behavior during the maximal incremental test and the EMGT and LT power output were equivalent for both muscles. The validity of using EMG to estimate the LT power output in recreational cyclists was confirmed.
Moderate exercise positively impacts innate immune functions, bringing about a better resistance against infections and general immunosurveillance. Exercise of high workloads (i.e., high intensity and/or duration) such as elite marathon, on the other hand, may have detrimental effects over immune function, but neither how long nor how intense should be the exercise sessions to be deleterious is known, this being a matter of intense dispute. Exercise is, at the same time, one of the most powerful inducers of the 70 kDa family of heat shock proteins (HSPAs, formerly known as HSP70s), which are protein chaperones characterized by a marked anti-inflammatory potency, when located intracellularly (iHSPA), but may act as pro-inflammatory cytokines if in the extracellular space (eHSPA). The above observations led us to suppose that short-term exercise could impose long-lasting effects on macrophage function that should be related to the eHSPA-to-iHSPA ratio, viz. H-index. Sedentary adult male Wistar rats were then submitted to 20 min swimming sessions with an overload (as a percentage of body weight attached to the tail base) of either 2, 4, 6, or 8 %. Control animals were maintained at rest in shallow water. Monocyte/macrophage functions (phagocytic capacity, nitric oxide [NO], and hydrogen peroxide [H2O2]) were assessed just after and 12 h after exercise and compared with HSPA status and oxidative stress markers. The results showed that exercise increased phagocytosis and H2O2 immediately after the bouts in a workload-dependent way. This was accompanied by increased H-index but no alteration in the redox status. Enhanced phagocytic capacity persisted for up to 12 h, when a marked rise in NO production was also observed, but H-index resumes its control values, suggesting that immune alertness returned to basal levels. Of note was the detection of the cognate form of eHSPA (encoded by hspa8 gene and formerly known as HSP73) in the rat sera. In total, acute exercise may evoke 12 h long workload-dependent effects associated with HSPA status.
The treatment of renal anaemia in HD patients with i.v. Q2W darbepoetin alfa effectively and safely maintains Hb concentrations at a less frequent dosing regimen than observed with QW administration. Dose requirements for i.v. darbepoetin alfa administered QW or Q2W were not different. The results of this study demonstrate that i.v. darbepoetin alfa administered Q2W is an effective regimen for HD patients requiring anaemia treatment in routine clinical practice.
Michelangelo Buonarroti (1475-1564) was a master anatomist as well as an artistic genius. He dissected numerous cadavers and developed a profound understanding of human anatomy. Among his best-known artworks are the frescoes painted on the ceiling of the Sistine Chapel (1508-1512), in Rome. Currently, there is some debate over whether the frescoes merely represent the teachings of the Catholic Church at the time or if there are other meanings hidden in the images. In addition, there is speculation regarding the image of the brain embedded in the fresco known as "The Creation of Adam," which contains anatomic features of the midsagittal and lateral surfaces of the brain. Within this context, we report our use of Image Pro Plus Software 6.0 to demonstrate mathematical evidence that Michelangelo painted "The Creation of Adam" using the Divine Proportion/Golden Ratio (GR) (1.6). The GR is classically associated with greater structural efficiency and is found in biological structures and works of art by renowned artists. Thus, according to the evidence shown in this article, we can suppose that the beauty and harmony recognized in all Michelangelo's works may not be based solely on his knowledge of human anatomical proportions, but that the artist also probably knew anatomical structures that conform to the GR display greater structural efficiency. It is hoped that this report will at least stimulate further scientific and scholarly contributions to this fascinating topic, as the study of these works of art is essential for the knowledge of the history of Anatomy.
Art and anatomy were particularly closely intertwined during the Renaissance period and numerous painters and sculptors expressed themselves in both fields. Among them was Michelangelo Buonarroti (1475-1564), who is renowned for having produced some of the most famous of all works of art, the frescoes on the ceiling and on the wall behind the altar of the Sistine Chapel in Rome. Recently, a unique association was discovered between one of Michelangelo's most celebrated works (The Creation of Adam fresco) and the Divine Proportion/Golden Ratio (GR) (1.6). The GR can be found not only in natural phenomena but also in a variety of human-made objects and works of art. Here, using Image-Pro Plus 6.0 software, we present mathematical evidence that Michelangelo also used the GR when he painted Saint Bartholomew in the fresco of The Last Judgment, which is on the wall behind the altar. This discovery will add a new dimension to understanding the great works of Michelangelo Buonarroti.
A number of published articles have suggested that each element of Renaissance art contains an inner meaning. Some of these elements include the choice of theme and protagonists, faces selected for the characters, colors used, species of flowers and trees chosen, animals depicted, positions of the elements, posture of the characters and their gestures, juxtapositions in the scenes, and even the very scenario or landscape. All of these elements are thought to have hidden meanings. In this context, this manuscript presents a new hypothesis suggesting that Michelangelo Buonarroti (1475-1564) may have concealed symbols associated with female anatomy in the ceiling of the Sistine Chapel (painted 1508-1512) in Rome. Thus, this paper is useful to better understand the history of anatomy and corroborates recent descriptions that have suggested the possible existence of anatomic figures concealed in many of Michelangelo's works. Clin. Anat. 29:911-916, 2016. © 2016 Wiley Periodicals, Inc.
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