From the gut to the peripheral tissues : the multiple effects of butyrate

Butyrate is a natural substance present in biological liquids and tissues. The present paper aims to give an update on the biological role of butyrate in mammals, when it is naturally produced by the gastrointestinal microbiota or orally ingested as a feed additive. Recent data concerning butyrate production delivery as well as absorption by the colonocytes are reported. Butyrate cannot be detected in the peripheral blood, which indicates fast metabolism in the gut wall and/or in the liver. In physiological conditions, the increase in performance in animals could be explained by the increased nutrient digestibility, the stimulation of the digestive enzyme secretions, a modification of intestinal luminal microbiota and an improvement of the epithelial integrity and defence systems. In the digestive tract, butyrate can act directly (upper gastrointestinal tract or hindgut) or indirectly (small intestine) on tissue development and repair. Direct trophic effects have been demonstrated mainly by cell proliferation studies, indicating a faster renewal of necrotic areas. Indirect actions of butyrate are believed to involve the hormono-neuro-immuno system. Butyrate has also been implicated in down-regulation of bacteria virulence, both by direct effects on virulence gene expression and by acting on cell proliferation of the host cells. In animal production, butyrate is a helpful feed additive, especially when ingested soon after birth, as it enhances performance and controls gut health disorders caused by bacterial pathogens. Such effects could be considered for new applications in human nutrition

Generalized Contour Dynamics: A Review

Contour dynamics is a computational technique to solve for the motion of vortices in incompressible inviscid flow. It is a Lagrangian technique in which the motion of contours is followed, and the velocity field moving the contours can be computed as integrals along the contours. Its best-known examples are in two dimensions, for which the vorticity between contours is taken to be constant and the vortices are vortex patches, and in axisymmetric flow for which the vorticity varies linearly with distance from the axis of symmetry. This review discusses generalizations that incorporate additional physics, in particular, buoyancy effects and magnetic fields, that take specific forms inside the vortices and preserve the contour dynamics structure. The extra physics can lead to time-dependent vortex sheets on the boundaries, whose evolution must be computed as part of the problem. The non-Boussinesq case, in which density differences can be important, leads to a coupled system for the evolution of both mean interfacial velocity and vortex sheet strength. Helical geometry is also discussed, in which two quantities are materially conserved and whose evolution governs the flow

Aerobic Training in Rats Increases Skeletal Muscle Sphingomyelinase and Serine Palmitoyltransferase Activity, While Decreasing Ceramidase Activity

Sphingolipids are important components of cell membranes that may also serve as cell signaling molecules; ceramide plays a central role in sphingolipid metabolism. The aim of this study was to examine the effect of 5 weeks of aerobic training on key enzymes and intermediates of ceramide metabolism in skeletal muscles. The experiments were carried out on rats divided into two groups: (1) sedentary and (2) trained for 5 weeks (on a treadmill). The activity of serine palmitoyltransferase (SPT), neutral and acid sphingomyelinase (nSMase and aSMase), neutral and alkaline ceramidases (nCDase and alCDase) and the content of sphingolipids was determined in three types of skeletal muscle. We also measured the fasting plasma insulin and glucose concentration for calculating HOMA-IR (homeostasis model assessment) for estimating insulin resistance. We found that the activities of aSMase and SPT increase in muscle in the trained group. These changes were followed by elevation in the content of sphinganine. The activities of both isoforms of ceramidase were reduced in muscle in the trained group. Although the activities of SPT and SMases increased and the activity of CDases decreased, the ceramide content did not change in any of the studied muscle. Although ceramide level did not change, we noticed increased insulin sensitivity in trained animals. It is concluded that training affects the activity of key enzymes of ceramide metabolism but also activates other metabolic pathways which affect ceramide metabolism in skeletal muscles

Different expressions of trypsin and chymotrypsin in relation to growth in Atlantic salmon (Salmo salar L.)

The expressions of trypsin and chymotrypsin in the pyloric caeca of Atlantic salmon (Salmo salar L.) were studied in three experiments. Two internal (trypsin phenotypes, life stages) and three common external factors (starvation, feeding, temperatures) influencing growth rates were varied. Growth was stimulated by increased temperature and higher feeding rate, and it was depressed during starvation. The interaction between trypsin phenotype and start-feeding temperature affected specific activity of trypsin, but not of chymotrypsin. Trypsin specific activity and the activity ratio of trypsin to chymotrypsin (T/C ratio) increased when growth was promoted. Chymotrypsin specific activity, on the other hand, increased when there was a reduction in growth rate whereas fish with higher growth had higher chymotrypsin specific activity resulting in lower T/C ratio value. During a rapid growth phase, trypsin specific activity did not correlate with chymotrypsin specific activity. On the other hand, a relationship between specific activities of trypsin and chymotrypsin could be observed when growth declined, such as during food deprivation. Trypsin is the sensitive key protease under conditions favouring growth and genetically and environmentally affected, while chymotrypsin plays a major role when growth is limited or depressed. Trypsin specific activity and the T/C ratio value are shown to be important factors in the digestion process affecting growth rate, and could be applicable as indicators for growth studies of fish in captive cultures and in the wild, especially when food consumption rate cannot be measured

Hepatoselective Nitric Oxide (NO) Donors, V-PYRRO/NO and V-PROLI/NO, in Nonalcoholic Fatty Liver Disease: A Comparison of Antisteatotic Effects with the Biotransformation and Pharmacokinetics

ABSTRACT V-PYRRO/NO [O(2)-vinyl-1-(pyrrolidin-1-yl)diazen-1-ium-1,2-diolate] and V-PROLI/NO (O2-vinyl-[2-(carboxylato)pyrrolidin-1-yl]diazen-1-ium-1,2-diolate), two structurally similar diazeniumdiolate derivatives, were designed as liver-selective prodrugs that are metabolized by cytochrome P450 isoenzymes, with subsequent release of nitric oxide (NO). Yet, their efficacy in the treatment of nonalcoholic fatty liver disease (NAFLD) and their comparative pharmacokinetic and metabolic profiles have not been characterized. The aim of the present work was to compare the effects of V-PYRRO/NO and V-PROLI/NO on liver steatosis, glucose tolerance, and liver fatty acid composition in C57BL/6J mice fed a high-fat diet, as well as to comprehensively characterize the ADME (absorption, distribution, metabolism and excretion) profiles of both NO donors. Despite their similar structure, V-PYRRO/NO and V-PROLI/NO showed differences in pharmacological efficacy in the murine model of NAFLD. V-PYRRO/NO, but not V-PROLI/NO, attenuated liver steatosis, improved glucose tolerance, and favorably modified fatty acid composition in the liver. Both compounds were characterized by rapid absorption following i.p. administration, rapid elimination from the body, and incomplete bioavailability. However, V-PYRRO/NO was eliminated mainly by the liver, whereas V-PROLI/NO was excreted mostly in unchanged form by the kidney. V-PYRRO/NO was metabolized by CYP2E1, CYP2C9, CYP1A2, and CYP3A4, whereas V-PROLI/NO was metabolized mainly by CYP1A2. Importantly, V-PYRRO/NO was a better NO releaser in vivo and in the isolated, perfused liver than V-PROLI/NO, an effect compatible with the superior antisteatotic activity of V-PYRRO/NO. In conclusion, V-PYRRO/NO displayed a pronounced antisteatotic effect associated with liver-targeted NO release, whereas V-PROLI/NO showed low effectiveness, was not taken up by the liver, and was eliminated mostly in unchanged form by the kidney

Chosen problems of design procedures of high speed milling electrospindle with non -standard bearings

W pracy przeprowadzono analizę podstawowych problemów budowy i projektowania elektrowrzecion łożyskowanych magnetycznie. Starano się przy tym zwrócić szczególną uwagę na problemy związane z konstrukcją i doborem komponentów projektowanego systemu. Ponadto ogólnie omówiono budowę, zastosowanie łożysk magnetycznych oraz zdefiniowano wady i zalety ich stosowania w maszynach wirnikowych. Na tej podstawie zaproponowano koncepcyjne dwa rozwiązania elektrowrzeciona łożyskowanego magnetycznie. Pracę uzupełnia opis ogólnie przyjętej procedury projektowania złożonych systemów mechatronicznych, do których zaliczyć można nowoczesne wysokoobrotowe elektrowrzeciono łożyskowane magnetycznie. Oparto się przy tym o metodykę zaproponowaną przez Rolfa Isermanna.The analysis of basic problems considering structure and design of milling electrospindles with magnetic bearings was performed in the paper. The attention was especially paid to problems related to construction and proper selection of components of the system being designed. Moreover, general structure and applications of magnetic bearings was discussed, and advantages as well as disadvantages of using magnetic bearings in rotary machinery were defined. On this basis, two conceptions of electrospindle with magnetic bearings were proposed. Additionally, the paper describes general design procedure of complex mechatronic systems, as which the modern high speed electrospindles with magnetic bearings can be classified, proposed by R. Isermann

Petrographic characteristics of fluvioglacial deposits of the Odra lobe, Poland: a statistical analysis

The fluvioglacial deposits of the Odra lobe, laid down during the Pomeranian phase of the last glaciation in northeastern Germany and northwestern Poland, have been analysed petrographically and interpreted in a regional perspective. The deposits have been classified in terms of the percentage of 10 selected petrographical groups and 5 petrographical coefficients. Statistical analysis of their values has shown significant petrographic differences that relate to the morphological characteristics of the study area. The greatest petrographic diversity was observed between Mecklenburg–Western Pomerania and the Odra lobe as well as between the Odra lobe and middle Pomerania. The differentiating features are: crystalline rocks, grey Palaeozoic limestones and flints and all of the petrographical coefficients. The differences within the Odra lobe itself are small by comparison with those in the neighbouring regions. They are the most evident between Uckermark and theMyśliborskie Lakeland. The differentiating features are: flints and quartz as well as a maximumof four out of five petrographical coefficients

New tectonic elements in the Križna nappe between Bystra Valley and Strążyska Valley in the Tatra

The Sub-Tatric units was newly mapped for the implementation of the Detailed Geological Map of the Tatra Mountains at the scale of 1 : 10 000 (SmgT). Lithostratigraphic andtectonic field observations between the Bystra Valley and the Strążyska Valley allowed a newinterpretation of the geological structure of the area. The system of sheets has appeared to beeven more complicated than that advocated by Guzik and Kotański (1963). New sheets have been recognized: Grześkówki sheets (Lower and Upper sheets), which were distinguished from the former Grześkówki sheet (sensu Guzik & Kotański, 1963), and the Kazalnica sheet and Żywczańskie sheet, which were distinguished from the Samkowa Czuba sheet. Both Grześkówki sheets and Kazalnica sheet are composed of Carnian and Norian clastics or marly dolomites, Rhaetian limestones and Hettangian clayey-silty shales. The Lower Grzeoekówki and Kazalnica sheets lie in the inverted position and Żywczańskie sheet is composed of an isolated package of Lower Jurassic spotted marls and limestones lying in the normal position contrary to the inverted beds of the Samkowa Czuba sheet. The Spadowiec sheet has a wider spatial extent than it was postulated earlier. The Jastrzębia Turnia sheet probably does not exist in area between the valleys of Białego and Bystra