Ontogenetic development of chick cerebellar glomeruli

Neuroscience and Behavioral Physiology -     

Synthetic analog of the thymosinα1 fragment 24–28 alters the coagulating and aggregating activities of α-thrombin

A pentapeptide (EEAEN), which is the 24–28 fragment of the COOH-terminal sequence in the thymosin_α1 molecule highly homologous with the 54–58 region of hirudin (with the complementary anion-binding exosite in the thrombin molecule), was synthesized by a solid-phase method. Preincubation of α-thrombin with EEAEN in concentrations of 0.1 pM to 1 nM reduced its clotting activity while preincubation of this enzyme with EEAEN in concentrations of 0.01 to 1 nM reduced its platelet-aggregating activity. The reaction of EEAEN with thrombin is shown to be similar to the reaction of the entire thymosin_α1 molecule. It is concluded that the COOH-terminal thymosin_α1 peptide EEAEN may be the reactive site responsible for the antithrombin activity of thymosin_α1. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 7, pp. 26–29, July, 1995 Presented by I. P. Ashmarin, Member of the Russian Academy of Medical Sciences     

Growth and adipogenic differentiation of mesenchymal stromal bone marrow cells during culturing in 3D macroporous agarose cryogel sponges

We studied the possibility of population of macroporous agarose cryogel sponges by mesenchymal stromal bone marrow cells with their subsequent adipogenic differentiation. After 7-day culturing of mesenchymal stromal cells in agarose cryogel, the level of cell proliferation was 35%. After 3-week culturing in a medium inducing adipogenesis we observed accumulation of intracellular neutral lipids positively stained with Oil Red O. These findings can be used for the development of bioengineering constructions of the adipose tissue on the basis of spongy carriers. Translated from Kletochnye Tehnologii v Biologii i Medicine, No. 3, pp. 141–144, August, 2008     

Dietary polyamines promote the growth of azoxymethane-induced aberrant crypt foci in rat colon

We have examined whether dietary polyamines influence the formation and initial growth of azoxymethane (AOM)-induced aberrant crypt foci (ACF) in rat colon. Effects of a combination of dietary polyamines at three dose levels (putrescine: 50, 280, 740 nmol/g; spermidine: 10, 261, 763 nmol/g; spermine: 1, 31, 91 nmol/g) in the polyamine-poor AIN-76A diet were studied in animals in two different experimental situations: animals treated with AOM alone and animals treated with AOM + difluoromethylornithine (DFMO), a specific inhibitor of endogenous polyamine synthesis. In both experimental situations, dietary polyamines enhanced the growth of ACF, expressed as the number of large ACF (foci with three or more aberrant crypts, ACF > or = 3), whereas the formation of ACF, expressed as the number of ACF, was apparently not altered. In animals treated with AOM alone, maximal growth enhancing effect on ACF was nearly obtained with the median level of dietary polyamine. In rats fed a low polyamine diet, basic AIN-76A, DFMO reduced the growth of AOM-induced ACF by 83%. This inhibitory effect of DFMO was counteracted by dietary polyamines in a dose- dependent manner, and it was abolished at the highest level of polyamines. In conclusion, it was demonstrated that dietary polyamines are able to enhance the growth of AOM-induced ACF. Further, dietary polyamines reversed the DFMO-caused inhibition of ACF growth, probably by compensating for the DFMO-reduced endogenous polyamine synthesis.