• Reproductive and Developmental Biology
• /
• v.30 no.3
• /
• pp.175-180
• /
• 2006

This study was conducted to examine the effect of pre activation treatment and activation time of recipient cytoplasm on the development of bovine somatic cell nuclear transfer(NT) embryos. Donor cells were transferred and electrofused to enucleated oocytes before(pre-AC) or after activation(post-AC). Activation was induced with a combination of $Ca^{2+}$-ionophore(A23187) and DMAP. NT embryos were cultured in CR1aa containing 3 mg/ml BSA for 9 days. Some NT embryos were fixed at 0.5 to 2.5 hr after fusion(for post-AC) or activation(for pre-AC) for confocal microscopy. Developmental rate to the blastocyst stage was slightly high in the post-AC group(20.6%) compared to that of pre-AC group(15.3%). However, developmental speed of embryos in the pre-AC group was faster than that of embryos in the post-AC group. Development rates to the blastocyst stage were similar among different activation time before fusion(0.5,2 and 4 hr). The result of the present study suggests that development and nuclear morphology are affected f the activation status of the recipient cytoplasm before fusion.

• IMMUNE NETWORK
• /
• v.9 no.4
• /
• pp.115-121
• /
• 2009

Natural killer (NK) cells play key roles in innate and adaptive immune defenses. NK cell responses are mediated by two major mechanisms: the direct cytolysis of target cells, and immune regulation by production of various cytokines. Many previous reports show that the complex NK cell activation process requires de novo gene expression regulated at both transcriptional and post-transcriptional levels. Specialized un-translated regions (UTR) of mRNAs are the main mechanisms of post-transcriptional regulation. Analysis of posttranscriptional regulation is needed to clearly understand NK cell biology and, furthermore, harness the power of NK cells for therapeutic aims. This review summarizes the current understanding of mRNA metabolism during NK cell activation, focusing primarily on post-transcriptional regulation.

• The Journal of Economics, Marketing and Management
• /
• v.12 no.2
• /
• pp.11-18
• /
• 2024

Purpose: The purpose of this study is to suggest the activation plan of the post-construction sales through the results of a survey on the perception of Seoul citizens and experts. Research design, data and methodology: The purpose of this study is to suggest the activation plan of the post-construction sales through the results of a survey on the perception of Seoul citizens and experts. Results: According to a survey of Seoul citizens' perceptions, 76.7% of Seoul citizens were well aware of post-construction sales and recognized that post-construction sales would reduce pre-sale speculation and confusion in the real estate market. Second, 73.6% of Seoul citizens were willing to buy houses through post-construction sales, and third, 79.6% of Seoul citizens recognized that a post-sale system was necessary. Experts' opinions generally responded to the expansion of the introduction of post-construction sales, saying, 'It is necessary for both the public and the private sectors'. Second, while experts say that there are also positive effects, negative effects such as polarization centered on large corporations, an increase in sales prices, and a decrease in housing supply are also concerned. Third, experts responded that 'diversification of financing methods' is the most important task in revitalizing the post-sale system. Conclusions: The policy implications are that it is necessary to mandate the post-construction sales in the long term, and that the quality assurance system needs to be supplemented even if the sale is promoted post-construction sales. In addition, private participation is essential to revitalize the post-construction sales, and government support such as initial financing, low-interest rates, and various financing measures should be sought to expand private participation.

• Journal of Embryo Transfer
• /
• v.13 no.1
• /
• pp.11-19
• /
• 1998

This study was to determine the effect of ionomycin and 6-dimethylaminopurine (6-DMAP) and/or elcetrical stimulation on the oocyte activation and production of rabbit nuclear transplant embryos. The oocytes were collected from the oviduct of superovulated rabbits at 14 h post hCG injection and cultured in TCM-199 containing 10% FBS until 19 h post hCG injection. To determine the optimum concentration and exposure time of 6-DMAP, some oocytes were activated with 5 $\mu$M ionomycin for 5 min and then in 2.0 mM 6-DMAP for 0.5 to 3.0 h, or in 1.0 to 3.0 mM 6-DMAP for 2.0 h. Other control oocytes were stimulated electrically(3X, 1.25 kV/cm, 60 $\mu$sec) in 0.3 M mannitol solution supplemented with 100 $\mu$M CaCl$_2$ and MgCl$_2$. The nuclear donor embryos of 8-cell stage were synchronized to G$_1$ phase of 16-cell stage, and the recipient cytoplasms were obtained from removal of the first polar body and a portion of membrane bound cytoplasm of the oocytes collected at 15 h post hCG injection. A separated blastomere was injected into the perivitelline space of the enucleated oocytes. The oocytes injected with nucleus were cultured until 19 h post hCG and then electrofused and activated by electrical stimulation with or without ionomycin and 6-DMAP. These nuclear transplant embryos were cultured in TCM-199 containing 10% FBS in 39˚C, 5% CO2 incubator for 120 h. For the oncytes activated parthenogenetically with electrical stimulation with or with-out ionomycin and the various concentration of exposure time of 6-DMAP, the highest cleavage(92.3%) and development to blastocyst stage(41.0%) were resulted from the oocytes activated by ionomycin and 2.0 mM 6-DMAP for 2.0 h, which were found to be significantly(P<0.05) higher than the cleavage(45.2%) and developement to blastocyst stage(14.3%) from the oocytes activated with electrical stimulation. The significantly(P<0.05) more oocytes(71.4%) developed to 4 cell stage at 24 h post activation by ionomycin and 6-DMAP than those by electrical stimulation(18.9%). For the nuclear transplant embryos, the cleavage rate was similarly high in oocyte activation by electrical stimulation with(79.4%) or without ionomycin and 6-DMAP(70.5%). However, the embryo development to blastocyst stage was significantly(P<0.05) higher in oocyte activation by electrical stimulation with ionomycin and 6-DMAP(44.4%) than by electrical stimulation only(25.0%). The significantly(P<0.05) more nuclear transplant embryos(45.6%) developed to 4 cell stage at 18 h post activation by electrical stimulation with ionomycin and 6-DMAP than those by electrical stimulation only(10.6%). These results indicated that the supplemental oocyte activation by ionomycin and 6-DMAP with electrical stimulation enhanced and accelerated the preimplanted in vitro development of the rabbit nuclear transplant embryos.

• The Journal of Advanced Prosthodontics
• /
• v.5 no.2
• /
• pp.104-109
• /
• 2013

PURPOSE. Among the surface treatment methods suggested to enhance the adhesion of resin cement to fiberreinforced composite posts, conflicting results have been obtained with silanization. In this study, the effects of silanization, heat activation after silanization, on the bond strength between fiber-reinforced composite post and resin cement were determined. MATERIALS AND METHODS. Six groups (n=7) were established to evaluate two types of fiber post (FRC Postec Plus, D.T. Light Post) and three surface treatments (no treatment; air drying; drying at $38^{\circ}C$). Every specimen were bonded with dual-curing resin cement (Variolink N) and stored in distilled water for 24 hours at $37^{\circ}C$. Shear-bond strength (MPa) between the fiber post and the resin cement were measured using universal testing device. The data were analyzed with 1-way ANOVA and by multiple comparisons according to Tukey's HSD (${\alpha}$=0.05). The effect of surface treatment, fiber post type, and the interactions between these two factors were analyzed using 2-way ANOVA and independent sample T-tests. RESULTS. Silanization of the FRC Postec Plus significantly increased bond strength compared with the respective non-treated control, whereas no effect was determined for the D.T. Light Post. Heat drying the silane coupling agent on to the fiberreinforced post did not significantly improve bond strength compared to air-syringe drying. CONCLUSION. The bond strength between the fiber-reinforced post and the resin cement was significantly increased with silanization in regards to the FRC Postec Plus post. Bond strength was not significantly improved by heat activation of the silane coupling agent.

• The Journal of Korean Physical Therapy
• /
• v.27 no.3
• /
• pp.129-134
• /
• 2015

Purpose: The purpose of this study was to determine the influence of WBV exercise on CMJ and quadriceps muscle activation according to different frequency of vibration in soccer player and also to find effective frequency for leading appropriate treatment reaction. Methods: Thirty three subjects were randomly divided into three groups: the three groups are WBV group using 20 Hz frequency, WBV group using 30 Hz frequency and squat exercise group according to training method. The exercise program was conducted for six weeks. Subjects were measured on CMJ and quadriceps muscle activation. Results: Significant difference in CMJ was observed in the group I, II compared with the group III (p<0.05). Results of post-hoc, showed a significant difference in CMJ in on group I, II compared with the group III, but no a statistically significant difference between group I and II. Significant difference in quadriceps muscle activation was observed in the group I, II compared with the group III (p<0.05, p<0.01). Results of post-hoc, significant difference in quadriceps muscle activation in on group I, II compared with the group III and significant difference between group I and group II. Conclusion: This research intervened WBV for soccer players and compared the differences of CMJ and quadriceps muscle activation; as a result of the effective frequency for improving performance, there is a significant difference in CMJ and quadriceps muscle activation of WBV group with comparison of control group; and it was proved that WBV is effective using 30 Hz frequency for improving quadriceps muscle activation.

• Biomolecules & Therapeutics
• /
• v.27 no.6
• /
• pp.522-529
• /
• 2019

M1/M2 polarization of immune cells including microglia has been well characterized. It mediates detrimental or beneficial roles in neuroinflammatory disorders including cerebral ischemia. We have previously found that sphingosine 1-phospate receptor subtype 1 ($S1P_1$) in post-ischemic brain following transient middle cerebral artery occlusion (tMCAO) can trigger microglial activation, leading to brain damage. Although the link between $S1P_1$ and microglial activation as a pathogenesis in cerebral ischemia had been clearly demonstrated, whether the pathogenic role of $S1P_1$ is associated with its regulation of M1/M2 polarization remains unclear. Thus, this study aimed to determine whether $S1P_1$ was associated with regulation of M1/M2 polarization in post-ischemic brain. Suppressing $S1P_1$ activity with its functional antagonist, AUY954 (5 mg/kg, p.o.), attenuated mRNA upregulation of M1 polarization markers in post-ischemic brain at 1 day and 3 days after tMCAO challenge. Similarly, suppressing $S1P_1$ activity with AUY954 administration inhibited M1-polarizatioin-relevant $NF-{\kappa}B$ activation in post-ischemic brain. Particularly, $NF-{\kappa}B$ activation was observed in activated microglia of post-ischemic brain and markedly attenuated by AUY954, indicating that M1 polarization through $S1P_1$ in post-ischemic brain mainly occurred in activated microglia. Suppressing $S1P_1$ activity with AUY954 also increased mRNA expression levels of M2 polarization markers in post-ischemic brain, further indicating that $S1P_1$ could also influence M2 polarization in post-ischemic brain. Finally, suppressing $S1P_1$ activity decreased phosphorylation of M1-relevant ERK1/2, p38, and JNK MAPKs, but increased phosphorylation of M2-relevant Akt, all of which were downstream pathways following $S1P_1$ activation. Overall, these results revealed $S1P_1$-regulated M1/M2 polarization toward brain damage as a pathogenesis of cerebral ischemia.

• Journal of Embryo Transfer
• /
• v.8 no.2
• /
• pp.151-157
• /
• 1993

The present study was undertaken to determine the optimal condition for parthenogenetic activation of rabbit oocytes by electric stimulation in vitro in an attempt to develop nuclear transplantation techniques for cloning mammalian embryos and animals. Freshly ovulated oocytes were collected from superovulated rabbits from 13 to 26 hrs. after hCG injection. The cumulus-free oocytes were activated parthenogetically by repeated stimuli of square direct electric pulses in O.3M mannitol solution. After applying electric stimulations of different voltages, pulse durations and pulse times, all of the oocytes were cultured in TCM-199 with 10% FCS for 96 hours in a 5% $CO_2$ incubator, and their developmental potential in vitro was examined. The higher activation rate (68.9%) was achieved at the voltage of 2.0kv/cm, the pulse duration of 60 $\mu$sec and three pulse times and the activation rate of 100% was achieved at the pulse duration of 100 and 200 $\mu$sec, the voltage of 1.5kv/cm and three pulse times. Although the higher rates of activation of oocytes were achieved at 100 and 200 $\mu$sec, none of them developed to blastocyst in vitro. The oocytes collected 18~20 hours post hCG injection showed the highest rate of activation and development to blastocyst in vitro than the oocytes collected 13~15 or 25~26 hours post hCG injection. Therefore, it can be suggested that the application of electric stimulation of 2.0kv/cm, 60 $\mu$sec and three pulse times to the oocytes collected at 18~20 hours post hCG injection would be more beneficial for the parthenogenetic activation of oocytes in rabbits.

• Restorative Dentistry and Endodontics
• /
• v.42 no.4
• /
• pp.324-331
• /
• 2017

Objectives: This study evaluated smear layer removal by different chemical solutions used with or without ultrasonic activation after post preparation. Materials and Methods: Forty-five extracted uniradicular human mandibular premolars with single canals were treated endodontically. The cervical and middle thirds of the fillings were then removed, and the specimens were divided into 9 groups: G1, saline solution (NaCl); G2, 2.5% sodium hypochlorite (NaOCl); G3, 2% chlorhexidine (CHX); G4, 11.5% polyacrylic acid (PAA); G5, 17% ethylenediaminetetraacetic acid (EDTA). For the groups 6, 7, 8, and 9, the same solutions used in the groups 2, 3, 4, and 5 were used, respectively, but activated with ultrasonic activation. Afterwards, the roots were analyzed by a score considering the images obtained from a scanning electron microscope. Results: EDTA achieved the best performance compared with the other solutions evaluated regardless of the irrigation method (p < 0.05). Conclusions: Ultrasonic activation did not significantly influence smear layer removal.

• IMMUNE NETWORK
• /
• v.12 no.6
• /
• pp.230-239
• /
• 2012

Activation-induced cytidine deaminase (AID) is an enzyme that is predominantly expressed in germinal center B cells and plays a pivotal role in immunoglobulin class switch recombination and somatic hypermutation for antibody (Ab) maturation. These two genetic processes endow Abs with protective functions against a multitude of antigens (pathogens) during humoral immune responses. In B cells, AID expression is regulated at the level of either transcriptional activation on AID gene loci or post-transcriptional suppression of AID mRNA. Furthermore, AID stabilization and targeting are determined by post-translational modifications and interactions with other cellular/nuclear factors. On the other hand, aberrant expression of AID causes B cell leukemias and lymphomas, including Burkitt's lymphoma caused by c-myc/IgH translocation. AID is also ectopically expressed in T cells and non-immune cells, and triggers point mutations in relevant DNA loci, resulting in tumorigenesis. Here, I review the recent literatures on the function of AID, regulation of AID expression, stability and targeting in B cells, and AID-related tumor formation.