974 resultados para Human physiology


Relevância:

60.00% 60.00%

Publicador:

Resumo:

Translation of Leggi fisiologiche.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Several studies have tried to find countermeasures against musculoskeletal de-conditioning during bed-rest, but none of them yielded decisive results. We hypothesised that resistive vibration exercise (RVE) might be a suitable training modality. We have therefore carried out a bed-rest study to evaluate its feasibility and efficacy during 56 days of bed-rest. Twenty healthy male volunteers aged 24 to 43 years were recruited and, after medical check-ups, randomised to a non-exercising control (Ctrl) group or a group that performed RVE 11 times per week. Strict bed-rest was controlled by video surveillance. The diet was controlled. RVE was performed in supine position, with a static force component of about twice the body weight and a smaller dynamic force component. RVE comprised four different units (squats, heel raises, toe raises, kicks), each of which lasted 60 - 100 seconds. Pre and post exercise levels of lactate were measured once weekly. Body weight was measured daily on a bed scale. Pain questionnaires were obtained in regular intervals during and after the bed-rest. Vibration frequency was set to 19 Hz at the beginning and progressed to 25.9 Hz (SD 1.9) at the end of the study, suggesting that the dynamic force component increased by 90%. The maximum sustainable exercise time for squat exercise increased from 86 s (SD 21) on day 11 of the BR to 176 s (SD 73) on day 53 (p = 0.006). On the same days, post-exercise lactate levels increased from 6.9 mmol/l (SD2.3) to 9.2 mmol/l (SD 3.5, p = 0.01). On average, body weight was unchanged in both groups during bed-rest, but single individuals in both groups depicted significant weight changes ranging from -10% to + d10% (p < 0.001). Lower limb pain was more frequent during bed-rest in the RVE subjects than in Ctrl (p = 0.035). During early recovery, subjects of both groups suffered from muscle pain to a comparable extent, but foot pain was more common in Ctrl than in RVE (p = 0.013 for plantar pain, p = 0.074 for dorsal foot pain). Our results indicate that RVE is feasible twice daily during bed-rest in young healthy males, provided that one afternoon and one entire day per week are free. Exercise progression, mainly by progression of vibration frequency, yielded increases in maximum sustainable exercise time and blood lactate. In conclusion, RVE as performed in this study, appears to be safe.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

OBJECTIVES: Mobile phones (MP) are used extensively and yet little is known about the effects they may have on human physiology. There have been conflicting reports regarding the relation between MP use and the electroencephalogram (EEG). The present study suggests that this conflict may be due to methodological differences such as exposure durations, and tests whether exposure to an active MP affects EEG as a function of time. METHODS: Twenty-four subjects participated in a single-blind fully counterbalanced cross-over design, where both resting EEG and phase-locked neural responses to auditory stimuli were measured while a MP was either operating or turned off. RESULTS: MP exposure altered resting EEG, decreasing 1-4 Hz activity (right hemisphere sites), and increasing 8-12 Hz activity as a function of exposure duration (midline posterior sites). MP exposure also altered early phase-locked neural responses, attenuating the normal response decrement over time in the 4-8 Hz band, decreasing the response in the 1230 Hz band globally and as a function of time, and increasing midline frontal and lateral posterior responses in the 30-45 Hz band. CONCLUSIONS: Active MPs affect neural function in humans and do so as a function of exposure duration. The temporal nature of this effect may contribute to the lack of consistent results reported in the literature.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Arachidonic acid (AA) a precursor in the formation of eicosanoids which are lipid mediators with a number of functions in human physiology and pathology. The most of the eicosanoids act as proinflammatory mediators and contribute to the development and proliferation of tumors. In this thesis we evaluated two mediators: 15-deoxy-Δ12,14-PGJ2 (15d- PGJ2) and epoxieicosatrienoic acids (EETs) both act with an opposite activity of most eicosanoids, with an anti-inflammatory and and anti-tumoral action these two distinct mediators from AA pathway were used in this thesis in two different projects. First: 15d- PGJ2, was described that to have an antiproliferative activity and to induce apoptosis in several types of tumor cells however, the effect of 15d- PGJ2 in thyroid cancer cells was unknown in this sense, we tested in vitro cultured thyroid tumor cells, here in TPC1 cells, and treated with different concentrations of 15d- PGJ2 (0 to 20 uM) the treated cells showed a decrease in proliferation and an increase in apoptosis and a decrease in IL-6 release and relative expression. These key results together demonstrate that 15d- PGJ2 can be used as a new therapy for thyroid cancer. Second: The EETs are converted to their diols by soluble epoxy hydrolase (sEH) to maintain the stability of EETs and their anti-inflammatory activity, an inhibitor (TPPU) against was used to sEH in a periodontitis model induced with Aggregatibacter actinomycetemcomitans. The oral treatment in mice with TPPU and sEH Knockout animals showed bone loss reduction accompanied by a decrease in the osteoclastogenic molecules, like RANK, RANKL and OPG, demonstrating that pharmacological inhibition of sEH may have therapeutic value in periodontitis and inflammatory diseases that involve bone resorption.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

This book consists of two main parts. The first part offers a basic methodological introduction, presenting a concise but multifaceted overview of current problems of collective memory. The second part contains a set of interviews with former prisoners of concentration camps carried out by the authors. The research was conducted by Paweł Greń and Łukasz Posłuszny and focuses on issues of collective and cultural memory illustrated by individual life experiences of concentration camps prisoners. The field of oral history serves as the framework of analysis and narrative inquiry as its research tool. Interviews and additional research materials were collected by the authors and are not available in previous publications, making this work a precious supplement to the current scholarly body of knowledge and achievements in the discipline of memory studies. According to the authors, current historical and literary publications provide an incomplete picture of the WWII and its aftermaths for survivors, because descriptions of the war and imprisonment in the camp play still a dominate role in narratives. The importance of these issues in autobiographies is unquestionable and highly needed to create a common identity among generation of prisoners, though authors often wanted to perceive the fate of individuals in a broader perspective – including the periods before and after the war. Hence, interviews stressed personal experiences and their understanding over time by former prisoners. The interviews covered many topics on life before, during and after the camp – among them daily and neutral routines, but also difficult matters. The latter were connected on the one hand with traumatic events or harsh memories and emotions, and on the other hand with less extensively highlighted threads of prisoners’ lives - such as issues of the body and sexuality – and their dependence on particular representation or narrative. The authors are convinced that the book serves not only as a record of past remembered by eyewitnesses, but it also depicts their accounts in wider contexts and discourses, which expose specific dimensions of told and written stories. In the book Questions for Memory one examine the approach proposed by young scholars. Interviews were conducted from 2009-2011, seventy years after the end of the second world war, and this initiative was the result of questions and doubts of the authors from the existing literature. They also wanted to use the unique opportunity to meet with eyewitnesses and record their stories, because when they pass away we will irretrievably lose the possibility to listen to them and to pose sensitive questions. The majority of the interviewees were prisoners of KL Auschwitz-Birkenau, and their experiences differed greatly from each other based on social background and specific experience in the camps as well as their post-camp and postwar life. Aside from persons whose stories are already well known and open, readers will hear the stories of those who spoke only reluctantly and very rarely, or who had remained silent until the present author’s research. Qualitative differences between interviews occurred on the level of established relationship and atmosphere of trust, which varied according to circumstances and individual character and personality. For P. Greń and Ł. Posłuszny, each interviewed person is equally and highly valued due to the collected material and the personal experience of the meetings. Among the ten interviews placed in the book, seven of them are the stories told by women. Their testimonies exemplify realities of everyday prisoners’ existence and gravitate towards mirroring specifically feminine perspectives of imprisonment. For women, crucial problems stemmed from experiences of body that intertwine with suffering, feeling of shame and humiliation. Early discussions on holocaust literature and issues of representation that shaped the Polish narrative and collective memory imposed imperatives of silence on certain topics. A solution for reconciling heroic and inhuman deeds in stories with completely human physiology was impossible and improper for many years. There were also questions about life after, ways of dealing with a trauma or reflections on the present time. During conversations the authors attempted to come closer to something distant and incomprehensible for their generation and for people who did not experience the camps. Despite the fact that there have been seventy years of dealing with these events in literature, art, drama, film, memoirs and scientific works, the past still breeds more questions than answers. The book Questions for Memory serves as an example of this phenomenon.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Changes induced by PA on nucleic acid (NA) conformation and synthesis is proven to be a major reason for PA essentiality (1-3). However, PA interactions with other polyanions, for instance polyanionic membrane lipid bilayers and glyosaminoglycans have received less attention (3-4). The functional importance of these interactions still is an obscure but interesting area of cell and molecular biology, especially in mammalian cells for which specific PA transport systems are not fully characterized (5). In mammals, activity and turnover of the polyamine (PA) synthesis key enzyme is controlled by a set of proteins: Antizymes (OAZ1-3) and antizyme inhibitors (AZIN1 and 2). It is demonstrated that AOZ modulate polyamine uptake (6), and that PA transport to mitochondria is linked to the respiratory chain state and modulates mitochondrial permeability transition (7). Antizyme expression variants have been located in mitochondria, being proposed as a proapoptotic factor (7-8). AZIN 2 is only expressed in a reduced set of tissues that includes mast cells, where it is associated to mast cell granules membrane (9). This fact, together to the abnormalities observed in bone marrow derived mast cell granules when they are differentiated under restricted PA synthesis conditions (10 and unpublished results), point out to important roles of PA and their related proteins in structure and function of mast cell granules. We will also present novel biophysical results on tripartite interactions of PA that remark the interest of the characterization of PA interactions with lipid bilayers for biomedicine and biotechnology. Thus, the information reported in this paper integrates previously reported information with our still unpublished results, all indicating that PA and their related proteins also are important factors for structure and dynamics of biological membranes and their associated functions essential in human physiology; for instance, solute interchange with the environment (uptake and secretion), oxidative metabolism and apoptosis. The importance of these involved processes for human homeostasis claim for further research efforts. 1. Ruiz-Chica J, Medina MA, Sánchez-Jiménez F and Ramírez FJ (2001) Fourier Transform Raman study of the structural specificities on the interaction between DNA and biogenic polyamines. Biophysical J. 80:443-454. 2. Lightfoot HL, Hall J (2014) Endogenous polyamine function--the RNA perspective. Nucleic Acids Res. 42:11275-11290. 3. Igarashi K, Kashiwagi K (2010) Modulation of cellular function by polyamines. Int J Biochem Cell Biol. 42:39-51. 4. Finger S, Schwieger C, Arouri A, Kerth A, Blume A (2014) Interaction of linear polyamines with negatively charged phospholipids: the effect of polyamine charge distance. Biol Chem. 395:769-778. 5. Poulin R, Casero RA, Soulet D. (2012) Recent advances in the molecular biology of metazoan polyamine transport. Amino Acids. 42:711-723. 6. Kahana C (2009) Regulation of cellular polyamine levels and cellular proliferation by antizyme and antizyme inhibitor. Essays Biochem. 4:47-61. 7. Agostinelli E, Marques MP, Calheiros R, Gil FP, Tempera G, Viceconte N, Battaglia V, Grancara S, Toninello A (2010) Polyamines: fundamental characters in chemistry and biology. Amino Acids 38:393-403. 8. Liu GY, Liao YF, Hsu PC, Chang WH, Hsieh MC, Lin CY, Hour TC, Kao MC, Tsay GJ, Hung HC (2006) Antizyme, a natural ornithine decarboxylase inhibitor, induces apoptosis of haematopoietic cells through mitochondrial membrane depolarization and caspases' cascade. Apoptosis 11:1773-1788. 9. Kanerva K, Lappalainen J, Mäkitie LT, Virolainen S, Kovanen PT, Andersson LC (2009). Expression of antizyme inhibitor 2 in mast cells and role of polyamines as selective regulators of serotonin secretion. PLoS One 31:e6858. 10. García-Faroldi G, Rodríguez CE, Urdiales JL, Pérez-Pomares JM, Dávila JC, Pejler G, Sánchez-Jiménez F, Fajardo I (2010) Polyamines are present in mast cell secretory granules and are important for granule homeostasis. PLoS One 30:e15071.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

In contrast to the well-characterized effects of specialized proresolving lipid mediators (SPMs) derived from eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), little is known about the metabolic fate of the intermediary long-chain (LC) n-3 polyunsaturated fatty acid (PUFA) docosapentaenoic acid (DPA). In this double blind crossover study, shifts in circulating levels of n-3 and n-6 PUFA-derived bioactive lipid mediators were quantified by an unbiased liquid chromatography-tandem mass spectrometry lipidomic approach. Plasma was obtained from human subjects before and after 7 d of supplementation with pure n-3 DPA, n-3 EPA or placebo (olive oil). DPA supplementation increased the SPM resolvin D5n-3DPA (RvD5n-3DPA) and maresin (MaR)-1, the DHA vicinal diol 19,20-dihydroxy-DPA and n-6 PUFA derived 15-keto-PG E2 (15-keto-PGE2). EPA supplementation had no effect on any plasma DPA or DHA derived mediators, but markedly elevated monohydroxy-eicosapentaenoic acids (HEPEs), including the e-series resolvin (RvE) precursor 18-HEPE; effects not observed with DPA supplementation. These data show that dietary n-3 DPA and EPA have highly divergent effects on human lipid mediator profile, with no overlap in PUFA metabolites formed. The recently uncovered biologic activity of n-3 DPA docosanoids and their marked modulation by dietary DPA intake reveals a unique and specific role of n-3 DPA in human physiology.-Markworth, J. F., Kaur, G., Miller, E. G., Larsen, A. E., Sinclair, A. J., Maddipati, K. R., Cameron-Smith, D. Divergent shifts in lipid mediator profile following supplementation with n-3 docosapentaenoic acid and eicosapentaenoic acid.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

P>The current paper provides an overview of current knowledge on the structure and function of the eye. It describes in depth the different parts of the eye that are involved in the ocular manifestations seen in the mucopolysaccharidoses (MPS). The MPS are a group of rare inheritable lysosomal storage disorders characterized by the accumulation of glycosaminoglycans (GAGs) in cells and tissues all over the body, leading to widespread tissue and organ dysfunction. GAGs also tend to accumulate in several tissues of the eye, leading to various ocular manifestations affecting both the anterior (cornea, conjunctiva) and the posterior parts (retina, sclera, optic nerve) of the eye.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

The object of this study is to identify the learning styles (LS) used by the students of the subject of physiology of the exercise of the program of Physiotherapy, with the purpose of establishing a direct relationship later on between the learning styles and the possible pedagogic strategies that but they favor the compression of the physiology of the exercise 48 subject of second and third year of career they were interviewed through the instrument standardized compound number (CHAEA). This study carried out an analysis descriptive and of typical deviation of the data. They were differences statistically significant in the styles of active and reflexive learning, in front of the Theoretical and pragmatic styles what puts in evidence the necessity to generate pedagogic strategies inside the subject that this chord with the tendency of the active and reflexive learning of the students.