• MeSH
• fyziologická adaptace MeSH
• fyziologie výživy MeSH
• hladovění MeSH

BACKGROUND/AIMS: The feeding artery of dialysis vascular access is subjected to unusually high wall shear stress (WSS), a hemodynamic factor leading to vasodilatation, for at least several months after access creation. Physiologically, high WSS leads to compensatory endothelium-dependent vasodilatation. We supposed that the dilatation of the feeding artery continues to lower WSS during longer time period after access creation and that this process is limited by risk factors of endothelial dysfunction. METHODS: We examined the feeding artery of vascular accesses within 3 months, 1 and 2 years after access creation. By ultrasonography, we obtained internal diameter and blood velocity in the feeding arteries. We calculated wall shear rate (WSR). RESULTS: We examined 75 patients. Internal diameter rose from 3.9 +/- 0.1 mm (3 months) to 4.3 +/- 0.2 mm within the first year and to 4.6 +/- 0.2 mm within the second. Similarly, mean WSR decreased from 1,839 +/- 117 to 1,629 +/- 123 s(-1) and to 1,159 +/- 109 s(-1), respectively. The vasodilatation was limited by diabetes mellitus, hypercholesterolemia and hypertriglyceridemia. CONCLUSIONS: The feeding artery continues to dilate 2 years after access creation, with a simultaneous decrease in WSR. This process is dampened in patients with diabetes mellitus and dyslipidemia

• MeSH
• arterie fyziologie   ultrasonografie   MeSH
• cévní endotel fyziologie   MeSH
• diabetes mellitus patofyziologie   MeSH
• dialýza ledvin MeSH
• duplexní dopplerovská ultrasonografie MeSH
• financování organizované MeSH
• fyziologická adaptace MeSH
• hypercholesterolemie patofyziologie   MeSH
• hypertriglyceridemie patofyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• pevnost ve smyku MeSH
• senioři MeSH
• vazodilatace fyziologie   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH

Purpose: Arteries continuously respond to changing tissue demands and to hemodynamic conditions by altering their diameter and wall structure. The relatively slow dilatation of the feeding artery of vascular accesses continues at least two years after access creation with a continuous decrease in wall shear rate (WSR), which however, remains highly supra-physiological. The aim of this study was to test the hypothesis that after a longer time period the WSR returns to its baseline value. Methods: In a cross-sectional study patients with arteriovenous fistulae were classified into four groups according to the access vintage (from new access to accesses older than six years). The WSR, cross-sectional area, and mean circumferential wall stress were measured and compared between groups.Results: WSR decreased from group 1 (fistula < ninety days old) to group 4 (fistulae > six years old) with a concomitant increase in internal diameter. Patients with the oldest access had normal WSR values (compared to the contralateral brachial artery) and the largest internal diameter of the feeding artery. In diabetic patients the absolute values of WSR were higher and internal diameter was lower compared to nondiabetic patients.Conclusions: Brachial artery WSR is normal in accesses older than six years with an increased internal diameter and wall cross-sectional area as compared to "younger" accesses. This suggests a process of vascular remodeling with an increase in vascular wall mass and normalization of WSR to physiologic values at the price of increased mean cross-sectional wall stress.

• MeSH
• arteria brachialis patologie   patofyziologie   ultrasonografie   MeSH
• arteriovenózní zkrat * MeSH
• časové faktory MeSH
• dialýza ledvin * MeSH
• fyziologická adaptace MeSH
• hemodynamika * MeSH
• horní končetina krevní zásobení   MeSH
• lidé středního věku MeSH
• lidé MeSH
• lineární modely MeSH
• mechanický stres MeSH
• multivariační analýza MeSH
• průřezové studie MeSH
• regionální krevní průtok * MeSH
• rozdělení chí kvadrát MeSH
• rychlost toku krve MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Evropa MeSH

Po resekci střeva dochází v zažívacím traktu k řadě změn, jejichž cílem je zvýšit absorpci živin, vody a minerálů ze zbývajícího střeva. Tyto změny probíhají řadu měsíců po operačním zákroku, týkají se struktury střevní sliznice, peristaltické aktivity tenkého střeva a funkce jednotlivých enterocytů. Zásadní význam má zachování ilea, které má vyšší schopnost adaptace než jejunum a zpomaluje činnost proximálních oddílů zažívacího traktu. Je identifikována řada faktorů, které ovlivňují střevní adaptaci. Do tohoto procesu jsou zapojeny hormony, růstové faktory, regulační peptidy, složité nitrobuněčné signalizační kaskády, cytokiny a tkáňové faktory. Za nejdůležitější je považován GLP2 (glukagonu podobný peptid 2), který má pozitivní trofický vliv na střevní sliznici. Adaptaci střeva podporuje časná enterální výživa po resekčním výkonu. Do praxe se zavádí rekombinantní analog GLP2 teduglutid, který snižuje urychlenou evakuaci žaludku a žaludeční hypersekreci, zvyšuje střevní perfuzi a podporuje a urychluje proces střevní adaptace. Jeho podávání urychluje možnost ukončení od parenterální výživy u pacientů se syndromem krátkého střeva.

Gut resection is followed by wide changes in the gastrointestinal tract. The goal is to increase nutrient, water and mineral absorption in the remnant intestine. These changes are going on for several months. They affect gut mucosa structure, intestine peristaltic activity and enterocytes function. The crucial role is ileum preserving. Ileum has higher adaptation ability comparing to jejunum and inhibits peristaltic function of proximal parts of GIT. A lot of factors involved in intestinal adaptation were identified, hormones, growth factors, regulating peptides, intracellular signalizing cascades, cytokines and tissue factors. The most important seems to be GLP2 (glucagon like peptide 2) which has positive trophic influence on gut mucosa. Early enteral nutrition after gut resection enhances its adaptation. Recombinant analogueGLP2 teduglutide was introduced to be used in the short bowel syndrome treatment. It inhibits stomach evacuation and hypersecretion, increases intestine perfusion and enhances intestinal adaptation. Its long-term application accelerates the parenteral nutrition weaning.

• Klíčová slova
• střevní resekce,
• MeSH
• chirurgie trávicího traktu * MeSH
• enterální výživa MeSH
• fyziologická adaptace * MeSH
• glukagonu podobný peptid 2 metabolismus   MeSH
• lidé MeSH
• pooperační období MeSH
• regenerace MeSH
• střeva * fyziologie   chirurgie   MeSH
• střevní sliznice fyziologie   MeSH
• syndrom krátkého střeva prevence a kontrola   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH
• přehledy MeSH

Prirodzená výživa materským mliekom je nenahraditeľným spôsobom výživy novorodencov, dojčiat a batoliat. Dojčenie poskytuje dieťaťu nielen najlepšiu – výživu, ale aj celý komplex faktorov, ktoré mu zabezpečujú najlepší priebeh adaptácie na samostatný život a prevenciu chorôb v detskom veku, aj neskôr v dospelosti. Autorky v príspevku sprístupňujú prieskum postojov matiek k dojčeniu.

The natural nutrition by human milk has been an irreplaceable way of food of newborns and infants. The breast-feeding has provided the best natural nutrition and also a wide complex of factors. It also provides the best adaptability for life and the prevention of diseases in child‘s age but also in maturity. The main aim was to put emphasis to the advantages of breast-feeding from different point of views.

• MeSH
• fyziologie výživy kojenců MeSH
• kojení * kontraindikace   metody   trendy   MeSH
• lidé MeSH
• mateřské mléko MeSH
• matky MeSH
• průzkumy a dotazníky MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Geografické názvy
• Slovenská republika MeSH

Developmental stages of the diplozoid monogenean Eudiplozoon nipponicum, comprising oncomiracidium, diporpa, juvenile, and adult, were investigated using light and scanning electron microscopy in conjunction with confocal scanning laser microscopy in order to examine body organization and identify explicit morphological adaptations to the ectoparasitic life in each stage. The parasite exhibits a complex digestive tract well equipped for hematophagous feeding. It consists of a mouth opening with prominent buccal suckers, eversible pharynx with adjacent glandular structures, and a blind-ending gut with cecal lining. Glandulo-muscular organs, located apically and opened into the mouth corner, are considered to be a part of the digestive tract. Based on our observations of pharynx eversion and in light of the presence of several glandular or gland-like structures, we propose a new hypothesis on the possibility of extracorporeal digestion of this parasite. The hindbody bears an attachment apparatus, comprising haptor, lobular extensions, and tegumental folds, responsible for the parasite's firm attachment to the host gills. The possibility of buccal suckers assisting in the parasite's translocation while searching for an optimal niche or their temporary attachment function during feeding is discussed. The body of each compound adult (i.e., permanent copula) is almost completely filled by two complete reproductive tracts comprising the female as well as male organs. Such a reproductive strategy, in which two independent heterogenic individuals fuse into a single hermaphrodite organism without the need to search for mating partner, represents a high specialization of diplozoids to their parasitic life.

• MeSH
• fyziologická adaptace MeSH
• hermafroditické organismy fyziologie   MeSH
• infestace ektoparazity parazitologie   patofyziologie   MeSH
• interakce hostitele a parazita fyziologie   MeSH
• kapři parazitologie   MeSH
• mikroskopie elektronová rastrovací MeSH
• parazitární onemocnění kůže parazitologie   patofyziologie   MeSH
• ploštěnci anatomie a histologie   fyziologie   ultrastruktura   MeSH
• rozmnožování fyziologie   MeSH
• stadia vývoje fyziologie   MeSH
• stravovací zvyklosti MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: Gregarines represent a very diverse group of early emerging apicomplexans, parasitising numerous invertebrates and urochordates, and are considered of little practical significance. Recently, they have gained more attention since some analyses showed that cryptosporidia are more closely related to the gregarines than to coccidia. METHODOLOGY/PRINCIPAL FINDINGS: Using a combined microscopic approach, this study points out the spectacular strategy of Gregarina cuneata for attachment to host tissue and nutrient acquisition while parasitising the intestine of yellow mealworm larvae, and reveals the unusual dynamics of cellular interactions between the host epithelium and parasite feeding stages. Trophozoites of G. cuneata develop epicellularly, attached to the luminal side of the host epithelial cell by an epimerite exhibiting a high degree of morphological variability. The presence of contractile elements in the apical region of feeding stages indicates that trophozoite detachment from host tissue is an active process self-regulated by the parasite. A detailed discussion is provided on the possibility of reversible retraction and protraction of the eugregarine apical end, facilitating eventual reattachment to another host cell in better physiological conditions. The gamonts, found in contact with host tissue via a modified protomerite top, indicate further adaptation of parasite for nutrient acquisition via epicellular parasitism while keeping their host healthy. The presence of eugregarines in mealworm larvae even seems to increase the host growth rate and to reduce the death rate despite often heavy parasitisation. CONCLUSIONS/SIGNIFICANCE: Improved knowledge about the formation of host-parasite interactions in deep-branching apicomplexans, including gregarines, would offer significant insights into the fascinating biology and evolutionary strategy of Apicomplexa. Gregarines exhibit an enormous diversity in cell architecture and dimensions, depending on their parasitic strategy and the surrounding environment. They seem to be a perfect example of a coevolution between a group of parasites and their hosts.

• MeSH
• aktiny metabolismus   MeSH
• Apicomplexa cytologie   fyziologie   ultrastruktura   MeSH
• epitel metabolismus   parazitologie   ultrastruktura   MeSH
• epitelové buňky metabolismus   parazitologie   ultrastruktura   MeSH
• fyziologická adaptace * MeSH
• interakce hostitele a patogenu MeSH
• myosiny metabolismus   MeSH
• symbióza * MeSH
• Tenebrio parazitologie   MeSH
• transport proteinů MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Insect evolution, from a free to a parasitic lifestyle, took eons under the pressure of a plethora of ecological and environmental drivers in different habitats, resulting in varying degrees of interactions with their hosts. Most Drosophilidae are known to be adapted to feeding on substrates rich in bacteria, yeasts and other microfungi. Some of them, mainly those in the Steganinae subfamily, display a singular behaviour, feeding on animal tissues or secretions. This behaviour may represent an evolving tendency towards parasitism. Indeed, while the predatory attitude is typical for the larval stages of a great proportion of flies within this subfamily, adult males of the genera Amiota, Apsiphortica and Phortica display a clearly zoophilic attitude, feeding on the lachrymal secretions of living mammals (also referred as to lachryphagy). Ultimately, some of these lachryphagous species act as vectors and intermediate hosts for the spirurid nematode Thelazia callipaeda, which parasitizes the eyes of domestic and wild carnivores and also humans. Here we review the scientific information available and provide an opinion on the roots of their evolution towards the parasitic behaviour. The distribution of T. callipaeda and its host affiliation is also discussed and future trends in the study of the ecology of Steganinae are outlined.

• MeSH
• biologická evoluce MeSH
• Drosophilidae parazitologie   fyziologie   MeSH
• infekce hlísticemi řádu Spirurida parazitologie   přenos   veterinární   MeSH
• stravovací zvyklosti fyziologie   MeSH
• Thelazioidea fyziologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Animal microbiomes play an important role in dietary adaptation, yet the extent to which microbiome changes exhibit parallel evolution is unclear. Of particular interest is an adaptation to extreme diets, such as blood, which poses special challenges in its content of proteins and lack of essential nutrients. In this study, we assessed taxonomic signatures (by 16S rRNA amplicon profiling) and potential functional signatures (inferred by Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt)) of haematophagy in birds and bats. Our goal was to test three alternative hypotheses: no convergence of microbiomes, convergence in taxonomy and convergence in function. We find a statistically significant effect of haematophagy in terms of microbial taxonomic convergence across the blood-feeding bats and birds, although this effect is small compared to the differences found between haematophagous and non-haematophagous species within the two host clades. We also find some evidence of convergence at the predicted functional level, although it is possible that the lack of metagenomic data and the poor representation of microbial lineages adapted to haematophagy in genome databases limit the power of this approach. The results provide a paradigm for exploring convergent microbiome evolution replicated with independent contrasts in different host lineages. This article is part of the theme issue 'Convergent evolution in the genomics era: new insights and directions'.

• MeSH
• Bacteria klasifikace   genetika   izolace a purifikace   MeSH
• biologická evoluce MeSH
• Chiroptera genetika   mikrobiologie   fyziologie   MeSH
• DNA bakterií genetika   MeSH
• fylogeneze MeSH
• ptáci genetika   mikrobiologie   fyziologie   MeSH
• RNA ribozomální 16S genetika   MeSH
• stravovací zvyklosti MeSH
• střevní mikroflóra * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

BACKGROUND: Bed bugs (Heteroptera: Cimicidae) are a group of blood-feeding ectoparasites. They mainly specialize on bats and birds, but a few species are important human pests. They exhibit several unique adaptations for their parasitic lifestyle. Among those, bed bug aggregations represent a striking example of a sub-social structure. However, their benefits for the bed bugs as well as their potential for bed bug control are largely unexplored. Young nymphs are known to disperse from the aggregations much less than older ones or adults. We therefore found possible that the aggregation age structure is connected with success in finding host and tested the effect of presence of adults on nymphal feeding success. RESULTS: We tested the effect of presence of adults on feeding success of first-instar nymphs using an artificial feeding system. We found that presence of fed adults causes larger proportion of nymphs to feed. CONCLUSIONS: Based on our data, fed bed bugs seem to trigger the young nymphs to actively forage. Since the first instar is much less viable than later stages, our finding points to an adaptive behavior that economizes on foraging energy cost. In the context of bed bug control, knowledge on such behavior emphasizes the prevention of fed bed bugs from returning to harborages. Bed bug traps may thus be used not just as means of bed bug monitoring, but also as means of control.

• MeSH
• nymfa fyziologie   MeSH
• štěnice fyziologie   MeSH
• stravovací zvyklosti * MeSH
• věkové faktory MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH