94 resultados para Fresh and frozen human umbilical cord blood
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Since the discovery that endogenous lipid mediators show similar cannabimimetic effects as phytocannabinoids from CANNABIS SATIVA, our knowledge about the endocannabinoid system has rapidly expanded. Today, endocannabinoid action is known to be involved in various diseases, including inflammation and pain. As a consequence, the G-protein coupled cannabinoid receptors, endocannabinoid transport, as well as endocannabinoid metabolizing enzymes represent targets to block or enhance cannabinoid receptor-mediated signalling for therapeutic intervention. Based on the finding that certain endocannabinoid-like fatty acid N-alkylamides from purple coneflower ( ECHINACEA spp.) potently activate CB2 cannabinoid receptors we have focused our interest on plant fatty acid amides (FAAs) and their overall cannabinomodulatory effects. Certain FAAs are also able to partially inhibit the action of fatty acid amide hydrolase (FAAH), which controls the breakdown of endocannabinoids. Intriguingly, plants lack CB receptors and do not synthesize endocannabinoids, but express FAAH homologues capable of metabolizing plant endogenous N-acylethanolamines (NAEs). While the site of action of these NAEs in plants is unknown, endogenous NAEs and arachidonic acid glycerols in animals interact with distinct physiological lipid receptors, including cannabinoid receptors. There is increasing evidence that also plant FAAs other than NAEs can pharmacologically modulate the action of these endogenous lipid signals. The interference of plant FAAs with the animal endocannabinoid system could thus be a fortunate evolutionary cross point with yet unexplored therapeutic potential.
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Immunoglobulin E (IgE) mediates the immune response to parasites, but can also cause allergies. In humans maternal IgE is not transferred to cord blood and high levels of cord blood IgE are associated with subsequent allergy. In horses, both maternal IgG and IgE are transferred via colostrum; the IgE levels in the mare's serum, the colostrum and the foal's serum are correlated but the consequences of IgE transfer to foals are not known. By about 6 weeks of age the levels of IgE in foal serum have dropped to a nadir, at 6 months of age the level of IgE has risen only very slightly and is no longer correlated with the levels seen at birth, IgE(+) B-cells could be detected in lymphoid follicles of some foals at this age. Surprisingly, the levels of total IgE detected in a foals serum at 6 months of age are significantly correlated with the level in its serum at 1, 2 and even 3 years of age suggesting that by 6 months of age the foals are synthesizing IgE and that a pattern of relatively higher or lower total serum IgE has been established. The neonatal intestinal mucosa contained connective tissue mast cells which stained for bound IgE in foals up to 9 weeks of age but not mucosal mast cells, thereafter, the intestinal mast cells were IgE negative until 6 months of age. IgE antibodies to Culicoides nubeculosus salivary antigens were detected in Swiss born foals from imported Icelandic mares allergic to Culicoides spp. yet the foals showed no signs of skin sensitization and such second generation foals are known not to have an increased risk of developing allergy to Culicoides. Overall this evidence suggests there is a minimal effector role of maternal IgE also that maternal IgE has waned prior to the onset of IgE synthesis in foals and does not support maternal priming of IgE responses in foals. Furthermore the total levels of IgE in any given foal are seen to be relatively high or low from soon after the onset of IgE synthesis, and most likely they are determined by genetic factors.
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Only a few sites in the Alps have produced archaeological finds from melting ice. To date, prehistoric finds from four sites dating from the Neolithic period, the Bronze Age, and the Iron Age have been recovered from small ice patches (Schnidejoch, Lötschenpass, Tisenjoch, and Gemsbichl/Rieserferner). Glaciers, on the other hand, have yielded historic finds and frozen human remains that are not more than a few hundred years old (three glacier mummies from the 16th to the 19th century and military finds from World Wars I and II). Between 2003 and 2010, numerous archaeological finds were recovered from a melting ice patch on the Schnidejoch in the Bernese Alps (Cantons of Berne and Valais, Switzerland). These finds date from the Neolithic period, the Early Bronze Age, the Iron Age, Roman times, and the Middle Ages, spanning a period of 6000 years. The Schnidejoch, at an altitude of 2756 m asl, is a pass in the Wildhorn region of the western Bernese Alps. It has yielded some of the earliest evidence of Neolithic human activity at high altitude in the Alps. The abundant assemblage of finds contains a number of unique artifacts, mainly from organic materials like leather, wood, bark, and fibers. The site clearly proves access to high-mountain areas as early as the 5th millennium BC, and the chronological distribution of the finds indicates that the Schnidejoch pass was used mainly during periods when glaciers were retreating.
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The plakin family consists of giant proteins involved in the cross-linking and organization of the cytoskeleton and adhesion complexes. They further modulate several fundamental biological processes, such as cell adhesion, migration, and polarization or signaling pathways. Inherited and acquired defects of plakins in humans and in animal models potentially lead to dramatic manifestations in the skin, striated muscles, and/or nervous system. These observations unequivocally demonstrate the key role of plakins in the maintenance of tissue integrity. Here we review the characteristics of the mammalian plakin members BPAG1 (bullous pemphigoid antigen 1), desmoplakin, plectin, envoplakin, epiplakin, MACF1 (microtubule-actin cross-linking factor 1), and periplakin, highlighting their role in skin homeostasis and diseases.
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Over the past few decades, advances in ventricular assist device (VAD) technology have provided a promising therapeutic strategy to treat heart failure patients. Despite the improved performance and encouraging clinical outcomes of the new generation of VADs based on rotary blood pumps (RBPs), their physiologic and hematologic effects are controversial. Currently, clinically available RBPs run at constant speed, which results in limited control over cardiac workload and introduces blood flow with reduced pulsatility into the circulation. In this review, we first provide an update on the new challenges of mechanical circulatory support using rotary pumps including blood trauma, increased non-surgical bleeding rate, limited cardiac unloading, vascular malformations, end-organ function, and aortic valve insufficiency. Since the non-physiologic flow characteristic of these devices is one of the main subjects of scientific debate in the literature, we next emphasize the latest research regarding the development of a pulsatile RBP. Finally, we offer an outlook for future research in the field.
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Background: The cerebral network that is active during rest and is deactivated during goal-oriented activity is called the default mode network (DMN). It appears to be involved in self-referential mental activity. Atypical functional connectivity in the DMN has been observed in schizophrenia. One hypothesis suggests that pathologically increased DMN connectivity in schizophrenia is linked with a main symptom of psychosis, namely, misattribution of thoughts. Methods: A resting-state pseudocontinuous arterial spin labeling (ASL) study was conducted to measure absolute cerebral blood flow (CBF) in 34 schizophrenia patients and 27 healthy controls. Using independent component analysis (ICA), the DMN was extracted from ASL data. Mean CBF and DMN connectivity were compared between groups using a 2-sample t test. Results: Schizophrenia patients showed decreased mean CBF in the frontal and temporal regions (P < .001). ICA demonstrated significantly increased DMN connectivity in the precuneus (x/y/z = -16/-64/38) in patients than in controls (P < .001). CBF was not elevated in the respective regions. DMN connectivity in the precuneus was significantly correlated with the Positive and Negative Syndrome Scale scores (P < .01). Conclusions: In schizophrenia patients, the posterior hub-which is considered the strongest part of the DMN-showed increased DMN connectivity. We hypothesize that this increase hinders the deactivation of the DMN and, thus, the translation of cognitive processes from an internal to an external focus. This might explain symptoms related to defective self-monitoring, such as auditory verbal hallucinations or ego disturbances.
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Due to the constant expansion within the nanotechnology industry in the last decade, nanomaterials are omnipresent in society today. Nanotechnology-based products have numerous different applications ranging from electronic (e.g., advanced memory chips) to industrial (e.g., coatings or composites) to biomedical (e.g., drug delivery systems, diagnostics). Although these new nanomaterials can be found in many "everyday" products, their effects on the human body have still to be investigated in order to identify not only their risk, but also their potential benefits towards human health. Since the lung is commonly thought to be the main portal of entry into the human body for nanomaterials released within the environment, this review will attempt to summarise the current knowledge and understanding of how nanomaterials interact with the respiratory tract. Furthermore, the advantages and disadvantages of different experimental model systems that are commonly used to study this exposure route to the human body will be discussed.
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PURPOSE Therapeutic drug monitoring of patients receiving once daily aminoglycoside therapy can be performed using pharmacokinetic (PK) formulas or Bayesian calculations. While these methods produced comparable results, their performance has never been checked against full PK profiles. We performed a PK study in order to compare both methods and to determine the best time-points to estimate AUC0-24 and peak concentrations (C max). METHODS We obtained full PK profiles in 14 patients receiving a once daily aminoglycoside therapy. PK parameters were calculated with PKSolver using non-compartmental methods. The calculated PK parameters were then compared with parameters estimated using an algorithm based on two serum concentrations (two-point method) or the software TCIWorks (Bayesian method). RESULTS For tobramycin and gentamicin, AUC0-24 and C max could be reliably estimated using a first serum concentration obtained at 1 h and a second one between 8 and 10 h after start of the infusion. The two-point and the Bayesian method produced similar results. For amikacin, AUC0-24 could reliably be estimated by both methods. C max was underestimated by 10-20% by the two-point method and by up to 30% with a large variation by the Bayesian method. CONCLUSIONS The ideal time-points for therapeutic drug monitoring of once daily administered aminoglycosides are 1 h after start of a 30-min infusion for the first time-point and 8-10 h after start of the infusion for the second time-point. Duration of the infusion and accurate registration of the time-points of blood drawing are essential for obtaining precise predictions.
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Glucagon-like-peptide-1 (GLP1) analogs may induce thyroid or pancreatic diseases in animals, raising questions about their use in diabetic patients. There is, however, controversy regarding expression of GLP1 receptors (GLP1R) in human normal and diseased thyroid and pancreas. Here, 221 human thyroid and pancreas samples were analyzed for GLP1R immunohistochemistry and compared with quantitative in vitro GLP1R autoradiography. Neither normal nor hyperplastic human thyroids containing parafollicular C cells express GLP1R with either method. Papillary thyroid cancer do not, and medullary thyroid carcinomas rarely express GLP1R. Insulin- and somatostatin-producing cells in the normal pancreas express a high density of GLP1R, whereas acinar cells express them in low amounts. Ductal epithelial cells do not express GLP1R. All benign insulinomas express high densities of GLP1R, whereas malignant insulinomas rarely express them. All ductal pancreatic carcinomas are GLP1R negative, whereas 6/20 PanIN 1/2 and 0/12 PanIN 3 express GLP1R. Therefore, normal thyroid, including normal and hyperplastic C cells, or papillary thyroid cancer are not targets for GLP1 analogs in humans. Conversely, all pancreatic insulin- and somatostatin-producing cells are physiological GLP1 targets, as well as most acini. As normal ductal epithelial cells or PanIN 3 or ductal pancreatic carcinomas do not express GLP1R, it seems unlikely that GLP1R is related to neoplastic transformation in pancreas. GLP1R-positive medullary thyroid carcinomas and all benign insulinomas are candidates for in vivo GLP1R targeting.Modern Pathology advance online publication, 12 September 2014; doi:10.1038/modpathol.2014.113.
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Progress toward elucidating the 3D structures of eukaryotic membrane proteins has been hampered by the lack of appropriate expression systems. Recent work using the Xenopus oocyte as a novel expression system for structural analysis demonstrates the capability of providing not only the significant amount of protein yields required for structural work but also the expression of eukaryotic membrane proteins in a more native and functional conformation. There is a long history using the oocyte expression system as an efficient tool for membrane transporter and channel expression in direct functional analysis, but improvements in robotic injection systems and protein yield optimization allow the rapid scalability of expressed proteins to be purified and characterized in physiologically relevant structural states. Traditional overexpression systems (yeast, bacteria, and insect cells) by comparison require chaotropic conditions over several steps for extraction, solubilization, and purification. By contrast, overexpressing within the oocyte system for subsequent negative-staining transmission electron microscopy studies provides a single system that can functionally assess and purify eukaryotic membrane proteins in fewer steps maintaining the physiological properties of the membrane protein.