Ceskoslovenska fysiologie最新文献

Free radicals in otorhinolaryngology participate in the pathogenesis of many diseases. Antioxidants can act or preventively or ameliorate the diseases. Oxidative stress, in which is the predominance of free radicals to antioxidants, is present in many states like inflammation, atherosclerosis or tumors. Antioxidant capacity is increased not only by the application of antioxidants, but also due to positive emotions. In nasal and paranasal diseases is the role of the nitroxide radical very important. Vasocontrictive drugs decrease its level, pathologically increased levels are observed in asthma, allergic rhinitis and in sinusitis. Nitroxide protects organism against microorganisms and viruses. Oxidative stress supports the origin of nasal polyposis, takes part in disturbances of the hearing. Increased reactive oxygen species are engaged in tinnitus. In otitis media the level of lipoperoxides may be the marker of the severity of the disease. In Ménicre's syndrome the total antioxidant capacity is decreased. It is possible to conclude, that free radicals and antioxidants play an important role in otorhinolaryngological diseases.

Nonapeptide oxytocin (OT) is known primarily as an inducer of uterine contraction and milk ejection. Recently, there have been described its regulatory actions on various brain functions and on many peripheral actions including regulation of cell growth. The diversity of OT actions produced by the stimulation of OT receptors (OTR) is paralleled by a diversity of its signaling pathways. OTR belongs to the G-protein coupled receptors (GPCR) and unlike the receptors for vasopressin its actions are mediated by only one type of receptor. However, its actions are influenced by the location of OTR in the plasma membrane and its relationship to the membraneous lipid rafts. The occupation of OTR in different locations in plasma membrane determines the signaling pathway. Persistent activation of MAP kinases leads through nuclear mechanisms to the inhibition of cell growth while the transient activation is responsible for stimulation of cell growth. The review covers many areas of OTR signaling, including activation of orthosteric and allosteric sites on receptors, new signaling pathway utilizing various MAP kinases, stimulation of prostaglandine synthesis etc. The elucidation of the novel signaling pathways will help to develop new drugs influencing specific sites on OT signaling that may be used as agonists or antagonists in clinical therapy. Moreover, these new discoveries may represent a contribution for the knowledge of physiology and pharmacology not only of oxytocin receptor but also other GPCR.

Ciliary activity assessment attracts a great interest and has undergone dynamic progress since the last decades. The ciliary function is typically impaired in primary ciliary dyskinesia (PCD). The cilia are mostly examined in vitro, the sample is taken away from the nasal mucosa. Digital videomicroscopy is accessible for the cilia observation in vitro and represents a gold standard. Manual reading using this method is lengthy in comparison with a photomultiplier. Using the photomultiplier, light captured in an optical fibre is analysed automatically by a computer. With technological progress other methods gain ground such as automatical analysis of variance of grey degrees or photomultiplier connected with a scanning confocal microscope. A medium 199 is mostly used for preservation of the functioning cilia. To retain ciliary beat frequency (CBF) it is necessary to use a heated microscope stage. Average physiological CBF value is 11.5 Hz in adult population and 12.8 Hz in children.

Focal cerebral ischemia is an important cause of death and disability. Various experimental models were designed to study the pathophysiological mechanisms underlying ischemic damage and to evaluate putative neuroprotective strategies. The lack of correlation between the results of experimental and clinical studies resulted in much criticism of animal models of stroke. However, experimental models are undoubtedly the most important source of information on stroke pathophysiology, and will definitely remain an integral part of stroke research in the future. Due to much variability between different models, it is important to have a clear understanding of their pathophysiological characteristics - it is essential for correct interpretation of the experimental results. This aim of this review was to summarize the current knowledge about the mechanisms underlying the models of photothrombosis and endothelin-mediated focal ischemia.

Pathological conditions, which are the reason of indigestive and resorption in small intestine are linked with nutrition and are so-called malabsorptions. The reason of these conditions is on one hand decreasing of production abilities and on the other hand bad prosperity of farm husbandry eventually domestic animals. Malabsorptions are classified from pathological point of view to secondary and primary. To the first category belong the postsurgical state of digestive organs, malfunction of digestive organs from the various reasons such as decreasing of bile activity, decreasing of pancreas activity or for the reason of the malignant changes in the digestive organs or as the consequence of antibiotic treatment or cytostatics. The second category represents endogenous malfunction of intestine enzymes, which are linking with hypersensitivity to some kinds of feed. However the secondary malabsorptions are epiphenomenon several diseases, are in text also cure method mentioned, respectively mark of cure in some stadium diagnosed malabsorption. This present study is particulary oriented to pathogenesis and characterisation of the primary and secondary malabsorptions in the veterinary theory and praxis.

Antagonists of glutamate ionotropic receptors exhibit marked anticonvulsant action but also serious side effects, therefore attention is shifted to drugs influencing metabotropic glutamate receptors. These receptors are classified into three groups (I-III) and eight subtypes. Anticonvulsant action in experimental models was demonstrated for antagonists of group I receptors (mGluR1 and mGluR5) as well as for agonists of groups II (mGluR2 and mGluR3) and III (mGluR4, mGluR6, mGluR7 and mGluR8). Preclinical data are far from being complete but clear anticonvulsant action and absence of serious side effects speak in favor of further research.

Thirty five years ago, A.C. Guyton at al. published a description of the large model of physiological relations in a form of a graphic chart. The authors brought this large-scale chart to life using a modern simulation tool--Matlab/Simulink. The original layout, connections and descriptions were saved in the implementation, but contrary to the old system analysis diagram, the new one is also a functional simulation model itself. Thus, the new implementation gives the user the possibility to see and study behaviour of all model's variables in time. Authors also describe the technology of development of multimedia learning simulators.

DNA-damaging agents and radiation have a central role besides other cancer treatment modalities currently. The balance between DNA damage and capacity of DNA repair mechanisms determines the final therapeutic outcome. An elevated ability of cancer cells to recognize DNA damage and initiate DNA repair pathways is an important mechanism for therapeutic resistance and has a negative impact upon therapeutic efficacy. Pharmacological inhibition of recently detected targets of DNA repair with several small-molecule compounds, therefore, has the potential to enhance the cytotoxicity of anticancer agents.

Microscopical examination of brain tissue appears as a valuable process, which can acknowledge, complete or confute the acquired findings by functional experiments. The purpose of this work was to survey histo-morphological and functio-morphological techniques mostly used in the neuropathophysiological research with application examples. The most common pathological processes in the brain is possible to document with some of this methods. Whether there are developmental, traumatical, degenerative, on the base of ischemia, reperfusion developed or only functional changes. The work deals with methods histological-non-specific, that offer comprehensive image- as hematoxiline-eosine staining, Nissl staining, Golgi impregnation. Further with cyto- and histochemical techniques- as Fluoro-Jade staining and NADPH-diaphorase detection and with immunohistochemical methods, in which marking with anticalbindin and imaging of c-fos protein are noted.