328 research outputs found

    Rola insuliny i wybranych adipocytokin u pacjentek z zespołem policystycznych jajników (PCOS)

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    Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in women of reproductive age. It is manifested by hyperandrogenism, polycystic ovaries on ultrasound, oligomenorrhoea and anovulation. PCOS patients are more vulnerable to metabolic disorders: insulin resistance, obesity, endothelium dysfunction, atherosclerosis, and activation of proinflammatory factors. This association shows that PCOS might be an ovarian manifestation of a metabolic syndrome. Insulin resistance is also strongly correlated with reproductive failure. Approximately 100 factors, secreted in adipose tissue, are responsible for its regulation. Adipocytokines have been found to play an important role in regulating insulin sensitivity. Abnormal levels of adipokines are detected in patients with insulin resistance. Studies indicate that these factors, and their different activity in PCOS women, may affect changes observed in their metabolism and, especially, may participate in the development of insulin resistance. There are several adipokines whose role has been thoroughly investigated and many that we still know very little about, for example apelin and visfatin. Counseling PCOS patients about the possibility of developing metabolic syndrome, diabetes mellitus, and cardiovascular diseases should be a standard of care.Zespół policystycznych jajników (PCOS) jest najczęstszą endokrynopatią wśród kobiet w wieku rozrodczym. Manifestuje się hiperandrogenizmem, obrazem policystycznych jajników w ultrasonografii, zaburzeniami miesiączkowania o typie rzadkich miesiączek lub zaburzeniami owulacji. Pacjentki z PCOS są bardziej narażone na zaburzenia metaboliczne: insulinooporność, otyłość, nieprawidłowości endothelium, miażdżycę i aktywację czynników prozapalnych. Te zależności mogą świadczyć o tym, że PCOS może być jajnikową postacią zespołu metabolicznego. Insulinooporność silnie koreluje również z zaburzeniami rozrodu. Istnieje około 100 czynników produkowanych przez tkankę tłuszczową, odpowiedzialnych za funkcje regulacyjne. Adipocytokiny są ważnymi czynnikami regulującymi wrażliwość organizmu na insulinę. U pacjentek z insulinoopornością zauważalne są nieprawidłowe poziomy adipocytokin. Badania pokazują, że te czynniki i ich odmienna aktywność u kobiet z PCOS, może mieć wpływ na zmiany w ich metabolizmie, a w szczególności w rozwoju insulinooporności. Istnieje wiele adipokin, których rola jest dobrze poznana, lecz nadal rola wielu z nich jest niedostatecznie zbadana: między innymi apeliny i wisfatyny. Ocena czynników ryzyka zaburzeń metabolicznych, cukrzycy oraz choroby sercowo-naczyniowej powinna być standardem u kobiet z PCOS

    Does training-induced orthostatic hypotension result from reduced carotid baroreflex responsiveness?

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    As manned space travel has steadily increased in duration and sophistication, the answer to a simple, relevant question remains elusive. Does endurance exercise training - high intensity rhythmic activity, performed regularly for extended periods of time - alter the disposition to, or severity of, postflight orthostatic hypotension? Research results continue to provide different views; however, data are difficult to compare because of the following factors that vary between investigations: the type of orthostatic stress imposed (+Gz, lower body negative pressure (LBNP), head-up tilt); pretest perturbations used (exercise, heat exposure, head-down tilting, bed rest, water immersion, hypohydration, pharmacologically-induced diuresis); the length of the training program used in longitudinal investigations (days versus weeks versus months); the criteria used to define fitness; and the criteria used to define orthostatic tolerance. Generally, research results indicate that individuals engaged in aerobic exercise activities for a period of years have been reported to have reduced orthostatic tolerance compared to untrained control subjects, while the results of shorter term longitudinal studies remain equivocal. Such conclusions suggest that chronic athletic training programs reduce orthostatic tolerance, whereas relatively brief (days to weeks) training programs do not affect orthostatic tolerance to any significant degree (increase or decrease). A primary objective was established to identify the alterations in blood pressure control that contribute to training-induced orthostatic hypotension (TIOH). Although any aspect of blood pressure regulation is suspect, current research has been focused on the baroreceptor system. Reductions in carotid baroreflex responsiveness have been documented in exercise-trained rabbits, reportedly due to an inhibitory influence from cardiac afferent, presumably vagal, nerve fibers that is abolished with intrapericardiac denervation. The purpose of this investigation was to attempt to determine if similar relationships existed in men with varied levels of fitness, using maximal aerobic power, VO2 max, as the marker of fitness

    Zastosowanie selektywnych modulatorów receptora progesteronowego w leczeniu mięśniaków macicy oraz ich przyszłość w ginekologii

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    Uterine leiomyomata are benign, monoclonal tumors arising from smooth muscle cells, which belong to one of the most common pathologies of the female genital system. Current pharmacotherapies (oral contraceptives, progestins, GnRH analogs) are ineffective or of limited use for long-term treatment. Although there is still much debate regarding their etiology, it is very likely that progesterone and progesterone receptor play a key role in their development. Profound importance of progesterone in the female reproductive system has led to discovery of synthetic progesterone receptor ligands, which can poses the activity ranging from pure agonist activity, trough mixed agonist/antagonist activity, to pure antagonist activity. Development of selective progesterone receptor modulators (SPRM) has created new therapeutic options and has great potential in a number of gynecologic indications. So far, ulipristal acetate has been approved for emergency contraception, mifepristone as a progesterone receptor antagonist because of the unique property of this compound for termination of pregnancy. Recently, the European Commission has authorized ulipristal acetate for the pre-operative treatment of uterine fibroids. Superior efficacy of ulipristal acetate versus placebo, to reduce excessive uterine bleeding and to reduce total fibroid volume prior to surgery was demonstrated. Moreover, non-inferior efficacy of ulipristal acetate versus Gonadotropin Releasing Hormone (GnRH)-agonist to reduce excessive uterine bleeding prior to surgery of uterine fibroids has been documented. Ulipristal acetate is also characterized by a superior side-effect profile in comparison to leuprolide acetate in terms of serum estradiol levels and the proportion of patients with moderate-to-severe hot flashes during treatment. Regarding safety profile, except elevation of liver enzymes after telapristone and onapristone treatment, to date no serious untoward effects of other SPRM have been reported. The issue of endometrial effects of these compounds remains to be resolved, although observation that intrinsic agonist activity of SPRM prevents endometrial proliferation may suggest future use of these agents in prevention of endometrial hyperplasia. Other promising applications, including endometriosis, endometrial cancer, Cushing’s disease, Alzheimer disease or long-term contraception, are currently in development.Mięśniaki macicy to łagodne, monoklonalne guzy wywodzące się z komórek mięśni gładkich należące do najczęstszych patologii układu rozrodczego kobiet. Ich etiologia pozostaje ciągle tematem otwartej debaty, jakkolwiek wydaje się, iż kluczową rolę w ich rozwoju odgrywa progesteron oraz receptor progesteronowy. Dotychczasowe zachowawcze metody leczenia mięśniaków (doustna antykoncepcja, gestageny lub analogi GnRH) są nieskuteczne bądź niemożliwe do stosowania w długotrwałej terapii. Pojawienie się selektywnych modulatorów receptora progesteronowego (SPRM) otworzyło nowe możliwości terapeutyczne. Obecnie preparaty te są zarejestrowane w doraźnej antykoncepcji, terminacji ciąży i w leczeniu mięśniaków. Ponadto na etapie badań klinicznych trwają próby zastosowania SPRM w leczeniu endometriozy, raka endometrium, choroby Cushinga, choroby Alzheimera czy w długotrwałej antykoncepcji

    Active sound radiation control with secondary sources at the edge of the opening

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    © 2016 Elsevier Ltd Planar virtual sound barriers with secondary sources over the entire opening have been demonstrated an effective way to achieve global control of sound transmission through the opening, but loudspeakers in the middle of the opening affect ventilation, lighting and normal access through it. To avoid the problem, this technical note proposes to implement secondary sources at the edge of a cavity opening and investigates the active sound reduction performance of the system numerically and experimentally. Unlike secondary sources over the entire opening which can achieve sound reduction at any frequency as long as there are sufficient of them, there exists an upper bound of effective frequency for global control when secondary sources are at the edge of the opening; however, local control is always achievable. Preliminary experiments were conducted on an open wooden box and a semi-closed meeting room to support the conclusions

    Transport properties of N=4 supersymmetric Yang-Mills theory at finite coupling

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    Gauge theory-string theory duality describes strongly coupled N=4 supersymmetric SU(n) Yang-Mills theory at finite temperature in terms of near extremal black 3-brane geometry in type IIB string theory. We use this correspondence to compute the leading correction in inverse 't Hooft coupling to the shear diffusion constant, bulk viscosity and the speed of sound in the large-n N=4 supersymmetric Yang-Mills theory plasma. The transport coefficients are extracted from the dispersion relation for the shear and the sound wave lowest quasinormal modes in the leading order alpha'-corrected black D3 brane geometry. We find the shear viscosity extracted from the shear diffusion constant to agree with result of [hep-th/0406264]; also, the leading correction to bulk viscosity and the speed of sound vanishes. Our computation provides a highly nontrivial consistency check on the hydrodynamic description of the alpha'-corrected nonextremal black branes in string theory.Comment: 19 pages, LaTe

    Bosonic Description of Spinning Strings in 2+12+1 Dimensions

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    We write down a general action principle for spinning strings in 2+1 dimensional space-time without introducing Grassmann variables. The action is written solely in terms of coordinates taking values in the 2+1 Poincare group, and it has the usual string symmetries, i.e. it is invariant under a) diffeomorphisms of the world sheet and b) Poincare transformations. The system can be generalized to an arbitrary number of space-time dimensions, and also to spinning membranes and p-branes.Comment: Latex, 12 page

    Prevalence and abundance of Cryptosporidium parvum and Giardia spp. in wild rural rodents from the Mazury Lake District region of Poland

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    Prevalence and abundance of Cryptosporodium parvum and Giardia spp. were studied in 3 species of rodents from forests and abandoned agricultural fields in N.E. Poland (Clethrionomys glareolus n=459; Microtus arvalis n=274; Apodemus flavicollis n=209). Overall prevalence was consistently higher in the voles compared with A. flavicollis (70±6, 73±0 and 27±8% respectively for C. parvum and 93±9, 96±3 and 48±3% respectively for Giardia spp.). Prevalence and abundance of infection also varied markedly across 3 years with 1998 being a year of higher prevalence and abundance with both species. Fewer older animals (especially C. glareolus and M. arvalis) carried infection with C. parvum and infections in these animals were relatively milder. Although seasonal differences were significant, no consistent pattern of changes was apparent. Host sex did not influence prevalence or abundance of infection with C. parvum, but made a small contribution to a 4-way interaction (in 5-way ANOVA) with other factors in the case of Giardia spp. The 2 species co-occurred significantly and in animals carrying both parasites there was a highly signficant positive correlation between abundance of infection with each, even with between-year, seasonal, host age, sex and species differences taken into account. Quantitative associations were confined to the 2 vole species in the study. These results are discussed in relation to the importance of wild rodents as reservoir hosts and sources of infection for local human communities

    Matrix dynamics of fuzzy spheres

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    We study the dynamics of fuzzy two-spheres in a matrix model which represents string theory in the presence of RR flux. We analyze the stability of known static solutions of such a theory which contain commuting matrices and SU(2) representations. We find that irreducible as well as reducible representations are stable. Since the latter are of higher energy, this stability poses a puzzle. We resolve this puzzle by noting that reducible representations have marginal directions corresponding to non-spherical deformations. We obtain new static solutions by turning on these marginal deformations. These solutions now have instability or tachyonic directions. We discuss condensation of these tachyons which correspond to classical trajectories interpolating from multiple, small fuzzy spheres to a single, large sphere. We briefly discuss spatially independent configurations of a D3/D5 system described by the same matrix model which now possesses a supergravity dual.Comment: 26 pages, 3 figures, uses JHEP.cls; (v2) references adde

    Deforming baryons into confining strings

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    We find explicit probe D3-brane solutions in the infrared of the Maldacena-Nunez background. The solutions describe deformed baryon vertices: q external quarks are separated in spacetime from the remaining N-q. As the separation is taken to infinity we recover known solutions describing infinite confining strings in N=1{\mathcal{N}}=1 gauge theory. We present results for the mass of finite confining strings as a function of length. We also find probe D2-brane solutions in a confining type IIA geometry, the reduction of a G_2 holonomy M theory background. The relation between these deformed baryons and confining strings is not as straightforward.Comment: 1+13 pages. LaTeX. 3 Figures. Factor of 2N fixed to N for the IIA background. Minor changes to tex

    Predicting Inter-Species Cross-Talk in Two-Component Signalling Systems

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    Phosphosignalling pathways are an attractive option for the synthetic biologist looking for a wide repertoire of modular components from which to build. We demonstrate that two-component systems can be used in synthetic biology. However, their potential is limited by the fact that host cells contain many of their own phosphosignalling pathways and these may interact with, and cross-talk to, the introduced synthetic components. In this paper we also demonstrate a simple bioinformatic tool that can help predict whether interspecies cross-talk between introduced and native two-component signalling pathways will occur and show both in vitro and in vivo that the predicted interactions do take place. The ability to predict potential cross-talk prior to designing and constructing novel pathways or choosing a host organism is essential for the promise that phosphosignalling components hold for synthetic biology to be realised
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