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  • Author: E. Petrovová x
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Pre-Incubation and its Effect on the Development and Malformations of The Chick Embryo

Abstract

This study was conducted to evaluate the effect of eggs stored with and without pre-incubation on chick embryos with emphasis on: embryo body, heart weight, malformations, and mortality. For this study, a total of 120 chick embryos were divided into three groups, based on the length of storage before hatching (3, 7 and 10 days). Observations of the weight of chick embryo bodies, chick embryo hearts, and the level of mortality and appearance of malformations were noted. With an increase in days stored, the chick embryo’s weight decreased. The pre-incubation period had a positive effect on the weight of chick embryo, and chick hearts. Malformations, including: hydrocephalus, open body cavity and underdeveloped wings, were observed in all three groups, with the highest proportion seen in the pre-incubated hatching eggs stored for 10 days; this group also displayed the highest level of mortality. Non-pre-incubated eggs showed the most promise with better results in all experimental groups. In conclusion, the research suggests the optimal storage for chick embryos to be 3 days, with lowest levels of mortality, malformations and limited effects on the body and heart weight.

Open access
Enamel Remineralization Potential of Novel Dentifrice with Tetracalcium Phosphate/Monetite Powder Component

Abstract

The aim was to investigate the enamel health benefits of a novel toothpaste with active tetracalcium phosphate/monetite mixtures under de/remineralization cycling. The enamel de/remineralization cycling protocol was consisted of demineralization in 1% aqueous solution of citric acid at pH 3.6 with following treatment with toothpastes and soaking in remineralization storage solution. Effectiveness of toothpastes to promote remineralization was evaluated by surface microhardness measurements, enamel erosion depth, analysis of surface roughness and fluorescent optical method. The novel tetracalcium phosphate/monetite toothpaste had the same remineralization potential as commercial calcium silicate/phosphate toothpaste and significantly higher than control storage solution group (p<0.05). Surface roughness was significantly lower after addition of fluorides to dentifrice (p<0.05). The enamel erosion depth was significantly reduced by applying toothpastes as compared to negative control (p<0.05) and did not differ from calcium silicate/phosphate toothpaste (p>0.66). The results showed that dentifrice formulations containing active tetracalcium phosphate/monetite mixture with or without fluoride addition had excellent enamel remineralization potential under de/remineralization cycling and successfully promote remineralization of enamel with daily using in the form of toothpaste.

Open access
Effects of Cell Seeding Methods on Chondrogenic Differentiation of Rat Mesenchymal Stem Cells in Polyhydroxybutyrate/Chitosan Scaffolds

Abstract

The aim of our study was to examine the effects of passive and active cell seeding techniques on in vitro chondrogenic differentiation of mesenchymal stem cells (MSC) isolated from rat bone marrow and seeded on porous biopolymer scaffolds based on polyhydroxybutyrate/chitosan (PCH) blends. This paper is focused on the distribution of the cells on and in the scaffolds, since it influences the uniformity of the created extracellular matrix (ECM), as well as the homogenity of the distribution of chondrogenic markers in vitro which ultimately affects the quality of the newly created tissue after in vivo implantation. The three types of cell-scaffold constructs were examined by: fluorescence microscopy, SEM, histology and quantitative analysis of the glycosaminoglycans after chondrogenic cultivation. The results demonstrated that the active cells seeded via the centrifugation of the cell suspension onto the scaffold guaranteed an even distribution of cells on the bulk of the scaffold and the uniform secretion of the ECM products by the differentiated cells.

Open access
The Distribution and Structure of the Microvasculature of the Phallus in the Ostrich (Struthio camelus)

Abstract

This study determined the distribution and specialized morphology (gaps and fenestrations, irregular endothelium, internalization of luminal material) of vessels in the spongy and erectile tissue of the phallus in the ostrich. Specimens from the phallus harvested from 18 sexual mature and active ostriches were utilized. General routine fixation was used for tissue blocks and then they were processed conventionally for observation under the Transmission Electron Microscope (TEM). The spongy tissue in the root of the phallus exhibited several blood vessels (mainly venules) within connective tissue strands. The capillaries displayed thick and attenuated endothelial profiles, whereas the venules were lined with an attenuated endothelium. Both vessel types displayed fenestrations and prominent gaps supported by a continuation of the basal lamina. Numerous cytoplasmic processes extended from the capillary endothelium, in places appearing to enclose and sequestrate luminal contents by phagocytosis. The internalized material appeared in the form of relatively large, pale vesicles. The endothelium was extremely irregular in profile, in some instances appearing to be composed of more than one layer of squamous cells. The erectile tissue lining the phallic sulcus presented relatively few capillaries and venules. These vessels exhibited features similar to those seen in the spongy tissue but the endothelial cells were markedly more complex and irregular in design.

Open access