Comparison study on casein phosphopeptide-amorphous calcium phosphate paste and fluoride gel on remineralization of demineralized enamel lesions

Objective: Tooth surface undergoes continuous remineralization and demineralization. The aim of this study was to compare the effect of Caseinphosphopeptide-amorphous calcium phosphate [CPPACP] paste and Fluoride gel on the microhardness of demineralized enamel lesions

Methods: Frothy eight specimens of premolar teeth were chosen and randomly divided to 4 groups of 12. After the initial measurement of micro-hardness the specimens were immersed in demineralizing solution for 4 day and then the measurements were recorded again. Two groups [GL and G3] were treated with CPP-ACP and Fluoride gel respectively according to manufacturer's instruction. Two other groups [G2 and G4] were treated with CPP-ACP and fluoride gel every week for three months. After the treatments all specimens were taken into PH-cycling and the microhardness for each one were measured again. For data analysis, the Repeated Measures ANOVA test and the LSD tests were performed. In each group the percentage of micro-hardness recovery was measured

Results: Repeated Measures ANOVA and LED Test showed that the mean value of hardness was significantly decreased after demineralization in all groups [p=0.01]. There was no significant difference in mean hardness value in groups [GL, G3] after treatment [p=0.1, p=0.12] In groups [G2, G4] the mean hardness value were significantly increased [p<0.0001, p=0.1]. It is noticeable that the CPP-ACP was significantly more efficient than the fluoride gel

Conclusion: CPP-APC paste and fluoride gel both increase the micro-hardness of enamel when administrated for long time and repeated application

effect of macromolecule source and type of media during in vitro maturation of sheep oocytes on subsequent embryo development

Oocyte maturation and subsequent in vitro production [IVP] of embryos are affected by diverse groups of chemicals in maturation medium which are needed for successful mammalian oocyte maturation during which the dramatic cytoplasmic and nuclear reprogramming events take place. This study was designed to evaluate the effects of protein source [fetal bovine serum, FBS, and bovine serum albumin, BSA] as well as two different maturation media during in vitro maturation of ovine oocytes on subsequent embryo development. Cumulus oocyte complexes were recovered from ovaries obtained from slaughter house and cultured for 24 hr in either TCM-199 or SOFaa maturation medium supplemented with 10% [v/v] FBS or 0.8% [w/v] BSA. Data were analyzed by one-way ANOVA using Sigma Stat [Ver. 2]. A p-value smaller than 0.05 was considered statistically significant. The proportions of cleavage and total blastocyst [evaluated on days 3 and 6, respectively] were significantly higher in FBS than BSA supplemented groups, though no differences were observed between the two used different maturation media. The cryotolerance of blastocysts was negatively influenced by the presence of FBS rather than BSA during IVM. The quality of produced embryos, however, was affected neither by the source of macromolecules nor the maturation medium in terms of hatching rate, total blastocyst cells and inner cell mass/total cell ratio. The rate of oocyte development was improved by the presence of FBS, though the cryosurvival of resulting blastocysts was negatively influenced by the presence of the serum during in vitro production of sheep oocytes

effect of biopsy during precompacted morula stage on post vitrification development blastocyst derived bovine embryos

Improvements on embryo micromanipulation techniques led to the use of embryo biopsy in commercial embryo transfer programs for genetic analysis of preimplantation bovine embryos. The aim of this study was to evaluate the quality of bovine blastocyst derived from embryos biopsied at different precompacted morulae stages by assessment of cryosurvivability of the resulting blastocysts. The in vitro produced bovine embryos were subjected to biopsy at days 2,3, and 4 post-isemination with different cell numbers [4 to 16-cells]. Embryo cell biopsy was carried out in a 100 micro l drop of H-SOF following pronase drilling by aspiration of one blastomrere. The biopsied embryos were then cutured in SOFFaaBSA co-cultured with oviduct cells-monolayer until blastocyst formation. The blastocysts were cryopreserved at room temperature after exposure of equilibration [glycerol 1.4 M for 5 min and then glycerol 1.4 M and ethylene glycol 3.6 M for 5 min] and vitrification solutions [3.4 M glycerol and 4.6 M ethylene glycol]. The blastocysts were loaded into the center of 0.25 ml straws separated by air bubbles from 2 columns of sucrose 0.5 M and plunged immediately into liquid nitrogen. There was no significant difference in cryosurvivability of vitrified-warmed blastocysts derived from biopsied embryos at different pre-compacted morula stages. The quality of biopsy derived blastocysts was identical to that of non-biopsy derived ones in terms of post vitrification survival and hatching rates. In conclusion there was no preference between different times of embryo biopsy at precompacted morula stages in term of cryosurvivability of biopsy derived bovine blastocysts

Effects of timing on cell biopsy from pre-compacted morula stage bovine embryos on subsequent embryonic development

Embryo biopsy has potential applications in molecular research processes in domestic animals, besides its application in sex determination in embryo transfer programs. The objective of the present study was to assess the in vitro development of bovine embryos biopsied on different days of precompacted morula stage. Slaughterhouse-derived oocytes were matured in vitro, fertilized [Day-0] by frozen-thawed, Percol-separated spermatozoa and cultured on oviductal cell monolayer. The embryos were subjected to cell biopsy on Days 2, 3, and 4 postinsemination at 4-16-cell stages. The data were analyzed using ANOVA and Chi-squared tests [SigmaStat, version 2]. A p-value < 0.05 was considered significant. Biopsies carried out at 16-cell stage [Day-4] resulted in 94% of embryos developing to the blastocyst stage, which was significantly higher [p < 0.05] than the ones biopsied at 8-cell stage on Day-4 [64%], and those undergoing the procedure on Day-3 [49% and 46% at 4-cell and 8-cell stages, respectively] and Day-2 [39% and 33% at 4-cell and 8-cell stages, respectively]. No significant differences were observed between biopsied and non-biopsied embryos on a given day. The total cell number in biopsy-derived blastocysts ranged between 103 and 135. The difference in the number of total cells, dead cells and cell allocation to trophectoderm and inner cell mass between non-biopsied and biopsy-derived blastocysts was insignificant. Biopsy of bovine embryos at 4-16-cell stages had no adverse effects on in vitro developmental potentials and the 16-cell stage embryos, biopsied on Day-4 was the best stage for blastomere removal

effect of the duration of in vitro maturation [IVM] on parthenogenetic development of ovine Oocytes

The aim of this study was to compare the effect of time of parthenogenetic activation [22 hr versus 27 hr after In Vitro Maturation-IVM] on in vitro development of ovine oocytes using either single [lonomycin 5 microM for 5 minor Ethanol 7% for 7 m/n] or combined [ionomycin and ethanol with 6-DMAP 2 mM for 3 hr] activation treatments. The abattoir-derived in vitro matured activated oocytes were cultured in modified synthetic oviductal fluid and assessed for the cleavage, blastocyst, and hatching rates. The single-activated oocytes had a reduction in cleavage, blastocyst and hatching rates compared to the combined-activated oocytes [except for the cleavage at 27 hr]. In single-treated groups the rates of cleavage and blastocyst were increased as the maturation time was extended from 22 hrto 27 hr. The numbers of total cells and Inner Cell Mass [ICM], though insignificant, were greater in combined-treated groups compared to the single treatment. The number of ICM in Eth+6-DMAP group activated at 27 hr was lower than 22 hr. Nonetheless, irrespective of the activation protocol, development to the blastocyst stage, the numbers of total cell, ICM, and cell allocation [ICM/total cells] were significantly lower in parthenogenetic than fertilized embryos. In conclusion, though the cleavage and blastocyst rates in single-treated groups were positively influenced by the extension of duration of IVM [27 hr], there was a trend of decreased numbers of total cells and ICM in slightly aged oocytes. Moreover, developmental potential of ovine parthenotes, especially in young oocytes, was improved by the addition of 6-DMAP to the activation regimen