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Tissue Fluid (tissue + fluid)
Selected AbstractsMolecular Diversity of Vasotocin-Dependent Aquaporins Closely Associated with Water Adaptation Strategy in Anuran AmphibiansJOURNAL OF NEUROENDOCRINOLOGY, Issue 5 2010M. Suzuki Anuran amphibians represent the first vertebrates that adapted to terrestrial environments, and are successfully distributed around the world, even to forests and arid deserts. Many adult anurans have specialised osmoregulatory organs, in addition to the kidney (i.e. the ventral pelvic skin to absorb water from the external environments and a urinary bladder that stores water and reabsorbs it in times of need). Aquaporin (AQP), a water channel protein, plays a fundamental role in these water absorption/reabsorption processes. The anuran AQP family consists of at least AQP0-AQP5, AQP7-AQP10 and two anuran-specific types, designated as AQPa1 and AQPa2. For the three osmoregulatory organs, AQP3 is constitutively located in the basolateral membrane of the tight-junctioned epithelial cells, allowing water transport between the cytoplasm of these cells and the neighbouring tissue fluid at all times. On the other hand, AQPs at the apical side of the tight epithelial cells are different among these organs, and are named kidney-type AQP2, ventral pelvic skin-type AQPa2 and urinary bladder-type AQPa2. All of them show translocation from the cytoplasmic pool to the apical plasma membrane in response to arginine vasotocin, thereby regulating water transport independently in each osmoregulatory organ. It was further revealed that, in terrestrial and arboreal anurans, the bladder-type AQPa2 is expressed in the pelvic skin, together with the pelvic skin-type AQPa2, potentially facilitating water absorption from the pelvic skin. By contrast, Xenopus has lost the ability to efficiently produce pelvic skin-type AQPa2 (AQP-x3) because Cys-273 of AQP-x3 and/or Cys-273-coding region of AQPx3 mRNA attenuate gene expression at a post-transcriptional step, presumably leading to the prevention of excessive water influx in this aquatic species. Collectively, the acquisition of two forms of AQPa2 and the diversified regulation of their gene expression appears to provide the necessary mechanisms for the evolutionary adaptation of anurans to a wide variety of ecological environments. [source] Review article: lymphatic system and associated adipose tissue in the development of inflammatory bowel diseaseALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 6 2010P.-Y. Von Der Weid Summary Background, The lymphatic system plays critical roles in tissue fluid homoeostasis, immune defence and metabolic maintenance. Lymphatic vessels transport lymph, proteins, immune cells and digested lipids, allowing fluid and proteins to be returned to the blood stream, lipids to be stored and metabolized and antigens to be sampled in lymph nodes. Lymphatic drainage is mainly driven by rhythmic constrictions intrinsic to the vessels and critically modulated by fluid pressure and inflammatory mediators. Aim, To collect and discuss the compelling available information linking the lymphatic system, adiposity and inflammation. Methods, A literature search was performed through PubMed focusing on lymphatic system, inflammation, immune cells and fat transport and function in the context of IBD. Results, Evidence collected allows us to propose the following working model. Compromised lymph drainage, reported in IBD, leads to oedema, lymphangiogenesis, impaired immune cell trafficking and lymph leakage. Lymph factor(s) stimulate adipose tissue to proliferate and produce cytokines, which affect immune cell functions and exacerbate inflammation. Conclusions, Understanding the lymphatic system's role in immune cell trafficking and immune responses, contribution to fat transport, distribution, metabolism and implication in the pathogenesis of chronic intestinal inflammation may provide the basis for new therapeutic strategies and improved quality-of-life. [source] Variations in the Thickness and Composition of the Skin of the GiraffeTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 9 2010Farzana Sathar Abstract This study examined the skin of two 1- to 2-year-old male giraffes and one adult male, determining skin thickness and histological structure with reference to it functioning as a component of the features required for the maintenance of blood pressure, dermal armor, or thermoregulation. It has been argued that a tight skin surrounding the extremities of the giraffe aids in the movement of fluid against gravity, hence preventing pooling of blood and tissue fluid (edema), but the skin has also been implicated in the thermoregulatory capacities and defensive anatomy of many mammalian species. In one of the younger giraffes, one-half of the skin was analyzed from which close to 170 sites were measured. In the other young and adult giraffes, spot tests to confirm the pattern observed in the fully analyzed individual were undertaken. It was discovered that the skin varied in thickness across the entire body and within regions of the body. Histological evaluation revealed that the skin was mostly collagenous, although interesting patterns of elastic fiber densities were also apparent. The skin in the neck and legs exhibited a morphology that may assist in cardiovascular regulation of blood flow to and from the head and legs, and the skin of the trunk and anterior neck has the possibility of functioning in a protective role. The analyses performed could not add any new data regarding the thermoregulatory role already described for giraffe skin. Anat Rec 293:1615,1627, 2010. © 2010 Wiley-Liss, Inc. [source] An in vitro investigation of the bulk flow of fluid through apical foramina during simulated tooth extraction: a potential confounder in microbiological studies?INTERNATIONAL ENDODONTIC JOURNAL, Issue 4 2001A. Kapalas Aim,The ,pumping action' induced during tooth extraction may cause bacteria suspended in tissue fluids to be transposed from one anatomical compartment to another. Apart from causing bacteraemia, this may lead to inaccuracies in studies evaluating the presence and distribution of bacteria in and around tooth apices. The aim was to investigate the bulk flow of fluid through apical foramina during simulated extraction of teeth in an in vitro model. The influence of the presence or absence of a coronal restoration was also evaluated. Methodology,Twenty extracted single-rooted, human, mature, permanent teeth were used. Standard access cavities were prepared and the root canals located. Standardized micrographs of the apical foramina were obtained and their area (µm2) was calculated by image analysis software. The teeth were then set and sealed into polyvinylsiloxane (rubber base) impression material. Crystal violet dye was inoculated into the coronal half of the root canal system. Tooth extraction movements were simulated in the impression matrix and the leakage of dyes with and without the presence of a coronal restoration was examined. The procedure was repeated, following application of safranin dye in a coronal trough within the simulated rubber base gingival margin at the CEJ. The results were analysed statistically with the independent-samples t -test and the McNemar test. Results,In the absence of a coronal restoration crystal violet leaked out of the apical foramina in 18/20 teeth; conversely safranin leaked into the teeth through the apical foramina in 11/20 cases when applied to the external root surface. In the presence of an intact coronal restoration crystal violet dye leaked out in 6/20 teeth and conversely safranin leaked into 7/20 teeth. The presence of a coronal restoration significantly reduced (P = 0.002) dye leakage out of the root canal system. No associations were found for leakage of dye into the root canal system when applied externally. In addition, the amount of dye leakage was positively correlated with the area of the apical foramen in the presence of a coronal restoration (P = 0.009). Conclusion,The presence of a coronal restoration significantly reduced leakage of dye out of the apical foramen. Microbiological studies on root canals and periapical lesions using extracted teeth should take potential contamination from this source into account. [source] The Role of the Endometrium in Endocrine Regulation of the Animal Oestrous CycleREPRODUCTION IN DOMESTIC ANIMALS, Issue 1 2008T Krzymowski Contents A critical analysis of the results of research in the function of the endometrium was carried out and a view point presented. The role of the endometrium in endocrine regulation of the oestrus cycle can be summarized as follows: 1. The transfer of prostaglandin F2, (PGF2,) from the uterus to an ovary, which causes luteolysis, occurs mainly via the lymphatic pathways. 2. The system of retrograde transfer of PGs enables PGF2, and PGE2 to reach the myometrium and endometrium with arterial blood at high concentration. In the luteal phase, PGF2,, together with the increasing concentration of progesterone, constricts the arterial vessels of the uterus; in the follicular phase and in early pregnancy, PGE2 together with oestrogen and embryonic signals, relaxes the arterial vessels. In addition, this system protects the corpus luteum from premature luteolysis during the cycle and luteolysis during early pregnancy. 3. In days 10,12 of the cycle, the blood flow in the uterus decreases by 60,70% in pigs and around 90% in sheep. This causes ischaemia and local hypoxia confirmed by the presence of hypoxia inducible factor and thus remodelling of the endometrium commences. 4. The pulsatile elevations in PGF2, concentration occurring in the blood flowing out of the uterus during the period of luteolysis and the next few days, do not result from increased PGF2, synthesis as suggested in numerous studies. They are the effect of excretion of PGF2, and its metabolites together with lymph and venous blood and tissue fluids in which prostaglandin accumulates. [source] | ||||||||||