• Korean Journal of Microbiology
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• v.32 no.4
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• pp.280-284
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• 1994

Lack of lysosomal fusion with symbiosomes in symbiont-bearing Amoeba proteus may be due either to the presence of a component in the symbiosome membrane or to the absence of a component needed in the fusion process. Using monoclonal antibody as a probe, lipopolysaccharides were identified as symbiosome-membrane components contributed by symbionts and were found to be exposed on the cytoplasmic side of the membrane. In order to test whether lipopolysaccharides may play a role in the prevention of lysosome-symbiosome fusion, the antilipopolysaccharides antibody was microinjected and processed for double immunostaining in conjuction with anti-lysosome antibody as a lysosome-fusion indicator. Microinjection of the anti-LPS antibody caused symbiosomes to fuse with lysosomes, suggesting that X-bacterial lipopolysaccharides could be 'fusion-preventing' factors.

• Journal of Life Science
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• v.16 no.4
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• pp.566-570
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• 2006

Pronuclear microinjection (PMI) is a primary method for producing transgenic mice and offers a powerful tool for investigating gene function in vivo. The method has several reported advantages and disadvantages. Here, we report another potential shortcoming. The survival rate of fertilized one cell-stage embryos was significantly reduced after PMI procedure (65.4% (1202/1838)). In addition, the proportion of embryos developing to full-term was also significantly lower than that of embryos not undergoing PMI (26.5% (319/1202) vs 41.9% (57/136)). Moreover, 3 out of 21 (14.3%) founder control mice which were non-transgene-carrying littermates of transgenic founders showed histopathological changes in their liver, which was comparable to that in of transgenic lineages (4 out of 27 (14.8%)). In conclusion, the mechanical damages in chromosomes occurring during PMI procedure may be a potential factor influencing phenotypes of transgenic mice.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.41-41
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• 2002

Bovine cumulus-oocyte complexes were recovered from ovaries at a slaughter and then divided into five groups: control group(unvitrified oocytes), 0 hr. group(composed of oocytes vitrified before the onset of maturation) and 10, 14, and 20 hrs groups(vitrified respectively at 10, 14 and 20 hrs after the onset of maturation). The oocytes remained vitrified for 24 hrs, and then were thawed in 30℃ water bath. Survival and cleavage rates were defined as development rate on in vitro culture and stained with aceto-orcein or FDA test.

• Transactions of Materials Processing
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• v.15 no.1 s.82
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• pp.34-41
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• 2006

Microlens arrays were fabricated by a modified LIGA process composed of the exposure of a PMMA (Polymethylmethacrylate) sheet to deep x-rays and subsequent thermal treatment. A successful modeling and analyses for microlens formation were presented according to the experimental procedure. A nickel mold insert was fabricated by the nickel electroforming process on the PMMA microlens arrays fabricated by the modified LIGA process. For the replication of microlens arrays having various diameters with different foci on the same substrate, both hot embossing and microinjection molding processes have been successfully utilized with the fabricated mold insert. Replicated microlenses showed very good surface roughness with the order of 1 nm. The focal lengths of the injection molded microlenses were successfully estimated theoretically and also measured experimentally.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.5
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• pp.449-454
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• 1995

The present study was conducted to assess gene expression of bacterial lacZ driven by the SV40 promoter at early developmental stages of bovine embryos. The lacZ gene was linearized with BamHI digestion and introduced into the pronucleus by microinjection at 20 hrs after the commencement of in vitro fertilization. Intact bovine blastocysts were not stained with X-Gal, suggesting that there is no endogenous beta-galactosidase activity in these blastocysts. In contrast, the bovine blastocyst cells microinjected with the lacZ gene exerted a characteristic greenish-blue color originating from the bacterial beta-galactosidase activity, albeit at a low rate, i.e. 2.1% of the total fertilized oocytes injected. It was concluded, therefore, that the lacZ gene driven by the SV40 promoter could be used for an indirect screening method in which the presence of transgene is evaluated from the product of transgene expression.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.3
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• pp.427-434
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• 1994

The primordial germ cells (PGCs) were transfected in vitro and expressed the exogenous RSVLTR/${\beta}G2$ plasmid, suggesting thaI PGC is a possible vector for direct gene transfer into the germ line. Transfection efficiency of cell suspensions containing PGCs was 1.5% by liposome mediated DNA transfection. By microinjection of the transfected PGCs into the host germinal crescent, PGCs migrated via blood vessel to the future gonad and these transfected PGCs resulted in the RSVLTR/${\beta}G2$ expression in the gonad. The results from the seeding of PGCs on the chorioallantoic membrane were insufficient to test the hypothesis that PGCs can penetrate or invade the chorioallantoic membrane for transport via the circulatory system.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.09a
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• pp.23-28
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• 2005

Microlens arrays were fabricated using a modified LIGA process based on the exposure of a PMMA (Polymethylmethacrylate) sheet to deep x-rays and subsequent thermal treatment. A successful modeling and analyses for microlens formation were presented according to the experimental procedure. A nickel mold insert was fabricated by the nickel electroforming process on the PMMA microlens arrays fabricated by the modified LIGA process. For the replication of microlens arrays having various diameters with different foci on the same substrate, the hot embossing and the microinjection molding processes have been successfully utilized with the fabricated mold insert. Fabricated microlenses showed good surface roughness than the mold insert. The focal lengths of the injection molded microlenses were successfully measured experimentally and also estimated theoretically.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.465-466
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• 2012

• The Korean Journal of Pain
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• v.11 no.1
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• pp.23-29
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• 1998

Background: The present study was conducted to investigate effects of microinjection of bicuculline, GABA-A receptor antagonist, into the brain stem nuclei on the dorsal horn neuron responsiveness in rats with an experimental peripheral neuropathy. Methods: An experimental neuropathy was induced by a unilateral ligation of L5~L6 spinal nerves of rats. After 2~3 weeks after the surgery, single-unit recording was made from wide dynamic range (WDR) neurons in the spinal cord dorsal horn. Results: Responses of WDR neurons to both noxious and innocuous mechanical stimuli applied to the somatic receptive fields were enhanced on the nerve injured side. These enhanced responsiveness of WDR neurons were suppressed by microinjection of bicuculline into periaqueductal gray(PAG) or nucleus reticularis gigantocellularis(Gi). A similar suppression was also observed when morphine was microinjected into PAG or Gi. Suppressive action by Gi-bicuculline was reversed by naloxonazine, ${\mu}$-opioid receptor antagonist, microinjected into PAG whereas PAG-bicuculline induced suppression was not affected by naloxonazine injection into Gi. Gi-bicuculline induced suppression were reversed by a transection of dorsolateral funiculus(DLF) of the spinal cord. Conclusions: The results suggest that endogenous opioids, via acting on GABAergic interneurons in PAG and Gi, may be involved in the control of neuropathic pain by activating the descending inhibitory pathways that project to the spinal dorsal horn through DLF to inhibit the responsiveness of WDR neurons.

• Journal of Embryo Transfer
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• v.16 no.2
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• pp.73-78
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• 2001

This study was carried out to investigated developmental ability of IVM/IVF derived hanwoo embryos after DNA microinjection. Microinjected hanwoo embryos were cultured fur 7 days. The cleavage rates of DNA injected embrys(36.3%) was significantly lower than those of non-injected embryos(67.4%; p<0.05). The percentage of injected embryos reaching to the morulae and blastocyst was significantly lower than those of non-injected embryos(p<0.05). When injected embryo were cultured contaning L-ascorbic acid and $\alpha$-tocopherol for 168 hrs, the morulae and blastocyst rates were significantly higher than control(p<0.05). These results suggested that the addition of L-ascorbic acid and $\alpha$-tocopherol can enhanced development to the morulae and blastocyst of microinjected embryos and improved culture condition increased the transgenic hanwoo embryos.