• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.10a
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• pp.177-178
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• 2002

병윈성 비브리오균의 병원인자에는 hemolysin, protease, phospholipase A2, siderophore 외에도 콜레라균 만이 생산하는 cholera toxin 등이 있다. 이 중에서도 대부분의 병원성 비브리오균에서 생성되는 대표적인 인자는 hemolysin과 protease로 알려져 있다. Hemolysin은 혈액을 분해하는 독소로서 병원성 비브리오균의 분리ㆍ동정에 널리 이용 되고 있다. Hemolysin은 균의 배양초기에서 부터 서서히 생성되기 시작하여 대수증식기 말에 최대의 활성을 나타내며 안정기에 접어들면서 활성이 급격히 감소되는 것으로 보고되고 있다 (Kim et al., 1997). (중략)

• Pediatric Infection and Vaccine
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• v.16 no.2
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• pp.115-122
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• 2009

Diarrhea is one of the most common causes of morbidity and mortality in children worldwide. Rotavirus is the most common cause of infectious diarrhea both in developed and developing countries. However, bacterial causes such as Salmonella typhi and Vibrio cholerae still play an important role in developing countries. Newly developed vaccines for rotavirus, S. typhi, and V. choleae are highly immunogenic and safe in children.

• 대한예방의학회:학술대회논문집
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• 1996.10a
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• pp.143-144
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• 1996

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.309.2-309.2
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• 2002

The FimH subunit of type l-fimbriated Escherichia coli has been determined as a major cause of urinary tract infection. To produce a possible vaccine antigen against urinary tract infection, the fimH gene was genetically coupled to the ctxa2b gene, which was then cloned into pMAL -p2E expression vector. The chimaeric construction of pMALfimH/ctxa2b was transformed into Escherichia coli TB1 and its N-terminal amino acid sequence was analyzed. (omitted)

• Journal of Microbiology and Biotechnology
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• v.10 no.6
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• pp.865-872
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• 2000

Helocobacter phylori is the major cause of gastritis, peptic ulcer, and a principal risk factor for gastric cancer. As the firs step towards a vaccine against H. pylori infection, Hy.pylori urease was expressed and purified as a recombinant apoenzyme (rUrease) in E. coli. In order to develop an effective immunization protocol using rUrease, the host immune responses were evaluated after the oral immunization of mice with rUrease preparations plus cholera toxin relative to various conditions, such as the physical nature of the antigen, the frequency of the booster immunization, the dose of the antigen, and the route of administration. The protective efficacy was assessed using a quantitative culture following an H. pylori SS1 challenge. It was demonstrated that rUrease, due to its particulated nature, was more superior than the UreB subunit as a vaccine antigen. The oral immunization of rUrease elicited significant systemic and secretory antibody responses, and activated predominantly Th2-type cellular responses. The bacterial colonization was significantly reduced (~100-fold) in those mice immunized with three or four weekly oran doses of rUrease plus cholera toxin (p<0.05), when compared to the non-immunized/challenged controls. The protection correlated well with the elicited secretory IgA level against rUrease, and these secretory antibody responses were highly dependent on the frequency of the booster immunization, yet unaffected by the dose of the antigen (25-200$\mu\textrm{g}$). These results demonstrate the remarkable potential of rUrease as a vaccine antigen, thereby strengthening the possibility of developing an H. pylori vaccine for humans.

• Biomolecules & Therapeutics
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• v.11 no.3
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• pp.157-162
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• 2003

The generation of secretory IgA antibodies(Abs) for specific immune protection of mucosal surfaces depends on stimulation of the mucosal immune system, but this is not effectively achieved by parenteral or even oral administration of most soluble antigens. Thus, to produce a possible vaccine antigen against urinary tract infections, the uropathogenic E. coli (UPEC) adhesin was genetically coupled to the ctxa2b gene and cloned into a pMAL-p2E expression vector. The chimeric construction of pMALfimHIctxa2b was then transformed into E. coli K-12 TB1 and its nucleotide sequence was verified. The chimeric protein was then purified by applying the affinity chromatography. The purified chimeric protein was confirmed by SDS-PAGE and western blotting using antibodies to the maltose binding protein (MBP) or the cholera toxin subunit B (CTXB), plus the N-terminal amino acid sequence was analyzed. The orderly-assembled chimeric protein was confirmed by a modified $G_{M1}$-ganglioside ELISA using antibodies to adhesin. The results indicate that the purified chimeric protein was an Adhesin/CTXA2B protein containing UPEC adhesin and the $G_{M1}$-ganglioside binding activity of CTXB. This study also demonstrate that peroral administration of this chimeric immunogen in mice elicited high level of secretory IgA and serum IgG Abs to the UPEC adhesin. The results suggest that the genetically linked CTXA2B acts as a useful mucosal adjuvant, and that the adhesin/CTXA2B chimeric protein might be a potential antigen for oral immunization against UPEC.

• The Journal of Korean Society of Virology
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• v.28 no.4
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• pp.303-316
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• 1998

An attenuated classical swine fever virus (CSFV), Suri strain, is a variant derived from a vaccine virus, LOM strain. This study was performed to elucidate the molecular biologcal properties of CSFV Suri strain, and to obtain the basic data for molecular epidemiological approaches for the disease. The truncated form of gp55 gene without the C-terminal transmembrane domain, in size of 1,023bp, was amplified by RT-PCR and sequenced by dye terminator cyclic sequencing method, and inserted into BamHI site of pAcGP67B baculovirus vector, establishing a cloned pAcHEG plasmid. By the nucleotide sequences determined, 341 amino acid sequences were predicted. As compared the nucleotide and amino acid sequences of gp55 of Suri with the various CSFV, Suri strain showed the high homology over 99.1% with ALD and LOM strains, but comparably the lower homology with Alfort and Brescia. In comparison of amino acid sequence in variable domain of gp55 protein, the similar tendency of homology was observed. In hydrophobicity analysis, all of four CSFV strains revealed the analogous patterns of hydrophobicity. The numbers and locations of N-glycosylation site and cysteine residues in gp55 were analyzed, those of Suri strain being coincident with ALD and LOM strains. The results suggest that gp55 in Suri strain has the high similarity to those in ALD and LOM strains in terms of the nucleotide and amino acid sequences and the functional properties of gp55 protein.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.3
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• pp.133-140
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• 2004

The purpose of the present study was to elucidate the possible involvement of the medial vestibular nucleus (MVN) and inferior vestibular nucleus (IVN) following acute hypotension in the vestibuloautonomic reflex through vestibulosolitary or vestibuloventrolateral projections. Acute hypotension-induced cFos expression was assessed in combination with retrograde cholera toxin B subunit (CTb) tract tracing. After injection of CTb into the solitary region, CTb-labeled neurons were located prominently around the lateral borders of the caudal MVN and medial border of the IVN. The superior vestibular nucleus also had a scattered distribution of CTb-labeled neurons. After injection of CTb toxin into the unilateral VLM, the distributions of CTb-labeled neurons in the MVN and IVN were similar to that observed after injection into the solitary region, although there were fewer CTb-labeled neurons. In the caudal MVN, about 38% and 13% of CTb-labeled neurons were double-labeled for cFos after injection of CTb into the solitary region and the VLM, respectively. In the IVN, 14% and 7% of CTb-labeled neurons were double-labeled for cFos after injection of CTb into the solitary region and the VLM, respectively. Therefore, the present study suggests that acute arterial hypotension may result in activation of vestibulosolitary pathways that mediate behavioral and visceral reflexes, and vestibuloventrolateral medullary pathways that indirectly mediate vestibulosympathetic responses.

• Toxicological Research
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• v.18 no.2
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• pp.205-213
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• 2002

This study was undertaken to develop a subacute murine model for predicting occurrence of systemic anaphylaxis and to evaluate efficacy of various immunological parameters as the monitoring indices for the occurrence of anaphyalxis. The murine anaphyalxis model was developed through intraperitoneally sensitizing 100 $\mu\textrm{g}$ ovalbumin (OVA) in the presence of 1 mg alum and 300 ng cholera toxin twice a week interval followed by challenging 500 $\mu\textrm{g}$. OVA intravenously. Typical anaphylaxis symptoms were demonstrated at the both BALB/c mice, a strain prone to type-2 response, and C57BL/6 mice. a strain prone to type-1 response. Level of plasma histamine was approximately 50-fold or 30-fold higher in the mice sensitized with OVA than the mice sensitized with alum plus cholera toxin or the saline-treated mice after OVA challenge, respectively. Sensitization and challenge with OVA significantly enhanced plasma leukotriene $B_4$ level but not IgE levels in comparison with the control mice, which indicated the role of leukotriene $B_4$ for progression of anaphyalxis. Furthermore, among mice suffered from anaphylaxis, levels of OVA-specific IgGl were significantly higher in the BALB/c mice than in the C57BL/6 mice, which implied the genetic susceptibility for the induction of systemic anaphylaxis. Conclusively, simultaneous evaluation of histamine, leukotriene $B_4$, and allergen-specific IgG isotype may serve as more efficient monitoring tool for vaccine-related anaphyalxis.

• Journal of Physiology & Pathology in Korean Medicine
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• v.29 no.5
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• pp.416-421
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• 2015

This study was performed to comparative investigate the distribution of primary sensory and motor neurons associated with Daereung(PC7) acupoints by using neural tracing technique. A total 16 SD rats were used in the present study. After anesthesia, the rats received microinjection of 6 ㎕ of cholera toxin B subunit(CTB) into the corresponding sites of the acupoints Daereung(PC7), in the human body for observing the distribution of the related primary sensory neurons in dorsal root ganglia(DRGs) and motor neurons in the spinal cord(C3∼T4) and sympathetic ganglia. Three days after the microinjection, the rats were anesthetized and transcardially perfused saline and 4% paraformaldehyde, followed by routine section of the DRGs, sympathetic chain ganglia(SCGs) and spinal cord. Labeled neurons and nerve fibers were detected by immunohistochemical method and observed by light microscope equipped with a digital camera. The labeled neurons were recorded and counted. From this research, the distribution of primary sensory and motor neurons associated with Daereung(PC7) acupoints were concluded as follows. Muscle meridian related Daereung(PC7) controlled by spinal segments of C5∼T1, C6∼T4, respectively.