Omega-6 and omega-3 fatty acids metabolism pathways in the body of pigs fed diets with different sources of fatty acids

This study was carried out on 24 gilts (♀ Polish Large White × ♂ Danish Landrace) grown with body weight (BW) of 60 to 105 kg. The pigs were fed diets designed on the basis of a standard diet (appropriate for age and BW of pigs) where a part of the energy content was replaced by different fat supplements: linseed oil in Diet L, rapeseed oil in Diet R and fish oil in Diet F (6 gilts per dietary treatment). The fat supplements were sources of specific fatty acids (FA): in Diet L α-linolenic acid (C18:3 n?3, ALA); in Diet R linoleic acid (C18:2 n?6, LA) and in Diet F eicosapentaenoic acid (C20:5 n?3, EPA), docosapentaenoic acid (C22:5 n?3, DPA) and docosahexaenoic acid (C22:6 n?3, DHA). The protein, fat and total FA contents in the body did not differ among groups of pigs. The enhanced total intake of LA and ALA by pigs caused an increased deposition of these FA in the body (p < 0.01) and an increased potential body pool of these acids for further metabolism/conversions. The conversion efficiency of LA and ALA from the feed to the pig’s body differed among groups (p < 0.01) and ranged from 64.4% to 67.2% and from 69.4% to 81.7%, respectively. In Groups L and R, the level of de novo synthesis of long-chain polyunsaturated FA was higher than in Group F. From the results, it can be concluded that the efficiency of deposition is greater for omega-3 FA than for omega-6 FA and depends on their dietary amount. The level of LA and ALA intake influences not only their deposition in the body but also the end products of the omega-3 and omega-6 pathways.     

Characterisation of Mesothelioma-Initiating Cells and Their Susceptibility to Anti-Cancer Agents

Malignant mesothelioma (MM) is an aggressive type of tumour causing high mortality. One reason for this paradigm may be the existence of a subpopulation of tumour-initiating cells (TICs) that endow MM with drug resistance and recurrence. The objective of this study was to identify and characterise a TIC subpopulation in MM cells, using spheroid cultures, mesospheres, as a model of MM TICs. Mesospheres, typified by the stemness markers CD24, ABCG2 and OCT4, initiated tumours in immunodeficient mice more efficiently than adherent cells. CD24 knock-down cells lost the sphere-forming capacity and featured lower tumorigenicity. Upon serial transplantation, mesospheres were gradually more efficiently tumrigenic with increased level of stem cell markers. We also show that mesospheres feature mitochondrial and metabolic properties similar to those of normal and cancer stem cells. Finally, we show that mesothelioma-initiating cells are highly susceptible to mitochondrially targeted vitamin E succinate. This study documents that mesospheres can be used as a plausible model of mesothelioma-initiating cells and that they can be utilised in the search for efficient agents against MM.     

Modeling of proton spin relaxation in muscle tissue using nuclear magnetic resonance spin grouping and exchange analysis.

NMR spin relaxation experiments performed on healthy mouse muscle tissue at 40 MHz and 293 K are reported. The spin-lattice relaxation experiments were performed using different combinations of selective and nonselective radio frequency pulses. Relaxation experiments in the rotating frame at H1 = 10, 5 and 1 G are also reported. The experimental results were analyzed using the spin-grouping method, which yields the sizes of the resolved magnetization components as well as their T2's and T1's (or T1p's) for the nonexponential relaxation functions. These results were analyzed further for the exchange between different spin groups. It has been found that to explain all of these experimental data it was necessary to use a four-compartment model of the muscle tissue that consists of a lipid spin group, a "solid-like" spin group (mainly proteins), a "bulk water" spin group and a "bound water" spin group. The chemical exchange rate between "bulk" and "bound" water was found to be 29 +/- 9s-1 at room temperature. The exchange rate between the bound water and the solid moderator was estimated to be approximately 500 s-1.     

Chemical synthesis and biological activities of analogues of 2',5'-oligoadenylates containing 8-substituted adenosine derivatives.

The synthesis of sequence-specific 2'-5'-oligonucleotides and analogues of 2'-5' linked oligoadenylates containing 8-substituted adenosine derivatives [8-hydroxypropyladenosine (AHPr) and 8-hydroxyadenosine (AOH)] is reported. The reaction of 5'-phosphoroimidazolidate of 8-substituted adenosines under conditions of lead ion catalyst did not give the corresponding 2'-5' oligoadenylates containing pAHPr and pAOH. When these reactions were carried out in the presence of uranyl ion (UO2(2+] in place of lead ion as a catalyst, the desired 2'-5' oligoadenylates were obtained. The p5'AHPr2'p5'AHPr2'p5'AHPr and p5'AOH2'p5'AOH2'p5'AOH, p5'A2'p5'A2'pAOH were slightly resistant to snake venom phosphodiesterase. The both circular dichroism and 1H-NMR spectra studies were used to characterize the modified 2'-5' oligoadenylates. Further, the biological activity evaluations of 8-substituted analogues of 2-5A are also described.     

Slow calcium waves in cultivated postnatal rat skeletal myocytes

A variety of active agents increasing [Ca²⁺]_i in cultivated skeletal myocytes have been investigated. It was shown that, out of the agents such as noradrenaline, carbachol, caffeine, cyclopiazonic acid, and potassium solution, only the last one caused the formation of slow calcium waves in skeletal myocytes. These waves propagated not only near the location of the cell nucleus but also along the whole length of myocytes. It is supposed that this wave process can be related to the modulation of excitation-relaxation processes in skeletal muscles.     

Quantitative evaluation of freeze-substitution effects on preservation of nuclear antigens during preparation of biological samples for immunoelectron microscopy

Using quantitative evaluation of immuno-gold labeling and antigen content, we evaluated various automated freeze-substitution protocols used in preparation of biological samples for immunoelectron microscopy. Protein extraction from cryoimmobilized cells was identified as a critical point during the freeze-substitution. The loss of antigens (potentially available for subsequent immuno-gold labeling) was not significantly affected by freezing, while the cryosubstitution with an organic solvent caused a significant loss of antigens. While addition of water can improve visibility of some cell structures, it strengthened the negative effect of cryosubstitution on antigen loss by extraction. This was, however, significantly reversed in the presence of 0.5% glutaraldehyde in the substitution medium. Furthermore, we showed that the level of these changes was antigen-dependent. In conclusion, low concentrations of glutaraldehyde can be generally recommended for cryosubstitution rather than the use of pure solvent, but the exact conditions need to be elaborated individually for certain antigens.