• 한국동물위생학회지
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• 제22권4호
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• pp.325-347
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• 1999

This study was conducted to investigate the epidemiological, clinicopathological, microbiological, pathological observations and other tests from sudden death in feedlot cattle at the region of Sarari in Korea during the period from 1994 to 1999. Massive or sporadic occurrence of sudden death has been observed in 101 heads of 47 farmhouse. There were 20.8% in spring, 29.7% in summer, 16.8% in autumn, 32.7% in winter, and 62.3% in reproductive, 27.7% in growing, 5.0% in beef cattle, 5.0% in calf in prevalence of sudden death in cattle. Enterotoxemia(88.0%), pneumonia(3.5%), intestinal diarrhea(3.5%), liver abscess(1.5%) and indigestion(1.5%) were detected from 67 heads of sudden death cattle. In clinical observations, cattle were generally died of sudden recumbency with convulsions followed anorexia, depression, ataxia, muscular tremor, tachycardia and dyspnea without any premonitory symptoms. Epidemiological surveys showed no evidence that other factors such as pesticide, insecticide, fertilizer, chemical drug3 and those of others caused sudden death. Macroscopically, there were coagulation disorders of blood, congestion, edema and haemorrhage of lung, congestion and haemorrhages, watery and blood-tinged contents of small intestine. Histopathologically, we observed pulmonary congestion and haemorrhage, necrotic intestinal mucosa accompanied with haemorrhage and congestion, and also increased globule leukocytes between bronchial epithelia with mild pneumonia. Clinicopathologically, only elevation of blood glucose and aspartate aminotransferase(AST) was detected. Magnesium and calcium deficiency were not detected, but parasites were detected highly in normal and dead cattles. Microbiologically, Clostridium(Cl) pefringens were detected from small intestinal contents of 94% (63/67) of sudden death cattle and 51%(51/101) of slaughter cattle, and the population were $10^{6-8}$/cfu/$m\ell$ after 16~32 hours. Consequently, it was proved that the cause of death in cattle was enterotoxemia. Pathogenic test of mouse and goat inoculated with Cl perfringens type A toxin has been demonstrated as similar observation to natural cases. In antimicrobial susceptibility test, ampicillin, bacitracin, polymycin, cephalothin, penicillin, choramphenicol, erythromycin, tetracycline were highly susceptible, and amikacin, gentamicin, kanamycin, neomycin, streptomycin, sulfamethoxine, sulfamethazine were resistant. Cl perfringens were resisted for 4 hours in 3% formalin, 20 minutes in 4% phenol, 20 minutes in 0.5% mercuric chloride and 40 minutes in 0.1% sodium hydroxide, respectively. The useful method to prevent from occurrance of enterotoxemia in feedlot cattle was a dietary administration of antibiotics and miyari acid.

• Asian-Australasian Journal of Animal Sciences
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• 제27권8호
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• pp.1131-1140
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• 2014

This research focused on the effects of different doses of Bacillus subtilis KN-42 on the growth performance, diarrhea incidence, faecal bacterial flora, and the relative number of Lactobacillus and Escherichia coli in faeces of weaned piglets to determine whether the strain can serve as a candidate antimicrobial growth promoter. A total of 360 piglets (initial body weight $7.14{\pm}0.63$ kg) weaned at $26{\pm}2$ days of age were randomly allotted to 5 treatment groups (4 pens per treatment with 18 pigs per pen) for a 28-day trial. Dietary treatments were basal diet without any antimicrobial (negative control; NC), basal diet supplemented with 120 mg/kg feed of neomycin sulfate (positive control; PC) and basal diet supplemented with $2{\times}10^9$ (L), $4{\times}10^9$ (M) and $20{\times}10^9$ (H) CFU/kg feed of B. subtilis KN-42. During the overall period, average daily gain and feed efficiency of piglets were higher in groups PC, M, and H than those in group NC (p<0.05), and all probiotics and antibiotics groups had a lower diarrhea index than group NC (p<0.05). The 16S rDNA gene-based methods were used to analyze faecal bacterial flora on day 28 of experiment. The result of denaturing gradient gel electrophoresis analysis showed that supplementation of B. subtilis KN-42 to the diet changed the bacterial communities, with a higher bacterial diversity and band number in group M than in the other four groups. Real-time polymerase chain reaction analysis showed that the relative number of Lactobacillus were higher in groups PC and H than in group NC (p<0.05), and the supplemented B. subtilis KN-42 to the diet also reduced the relative number of E. coli (p<0.05). These results suggest that dietary addition of B. subtilis KN-42 can improve the growth performance and gastrointestinal health of piglets.

• Asian-Australasian Journal of Animal Sciences
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• 제27권11호
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• pp.1644-1651
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• 2014

Transgenic animals have become important tools for the production of therapeutic proteins in the domestic animal. Production efficiencies of transgenic animals by conventional methods as microinjection and retrovirus vector methods are low, and the foreign gene expression levels are also low because of their random integration in the host genome. In this study, we investigated the homologous recombination on the porcine ${\beta}$-casein gene locus using a knock-in vector for the ${\beta}$-casein gene locus. We developed the knock-in vector on the porcine ${\beta}$-casein gene locus and isolated knock-in fibroblast for nuclear transfer. The knock-in vector consisted of the neomycin resistance gene (neo) as a positive selectable marker gene, diphtheria toxin-A gene as negative selection marker, and 5' arm and 3' arm from the porcine ${\beta}$-casein gene. The secretion of enhanced green fluorescent protein (EGFP) was more easily detected in the cell culture media than it was by western blot analysis of cell extract of the HC11 mouse mammary epithelial cells transfected with EGFP knock-in vector. These results indicated that a knock-in system using ${\beta}$-casein gene induced high expression of transgene by the gene regulatory sequence of endogenous ${\beta}$-casein gene. These fibroblasts may be used to produce transgenic pigs for the production of therapeutic proteins via the mammary glands.

• 한국작물학회지
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• 제49권3호
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• pp.237-242
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• 2004

우용유전자 도입을 통한 신품종 톨페스큐를 개발할 목적으로 Agrobacterium을 이용한 효율적인 형질전환 체계를 확립하였다 톨페스큐 성숙종자 유래의 캘러스를 standard binary vector인 pIG121Hm을 가지는 Agrobacterium EHA101을 이용하여 감염시킨 후 공동배양하여 형질전환시켰다. Agrobacterium을 이용한 형질전환에 있어서 중요한 인자로 작용하는 몇 가지 요인에 대한 톨페스큐 캘러스의 형질전환 효율을 GUS 유전자의 발현정도로 조사하였다. Agrobacterium 감염시에 접종배지와 공동배양배지에 $200\mu\textrm{M}$의 acetosyringone(AS)을 첨가해 주었을 때 형질전환 효율이 증가 되었으며, 공동배양기간을 5일까지 증가시켰을 때 형질전환효율이 증가되었다. 또한 Agrobacterium 감염시에 $200\mu\textrm{M}$의 AS와 0.l%의 Tween20을 동시에 첨가해 주었을 때 가장 높은 형질전환 효율을 나타내었다. 50 mg/L.의 hygromycin이 첨가된 선발배지에서 살아남은 캘러스로부터 정상적인 식물체가 재분화 되었으며 이들 형질전환체를 GUS 염색과 Southern blot 분석을 실시하여 본 결과 발현백터의 T-DNA 영역이 형질전환 식물체의 genome에 성공적으로 도입되었음을 확인할 수 있었다. 본 연구를 통하여 확립된 효율적인 형질전환 시스템은 분자육종을 통한 신품종 톨페스큐의 개발에 유용하게 이용될 수 있을 것이다.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.101-101
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• 2003

Main strategy for a treatment of Parkinson's disease (PD), due to a progressive degeneration of dopaminergic neurons, is a pharmaceutical supplement of dopamine derivatives or ceil replacement therapy. Both of these protocols have pros and cons; former exhibiting a dramatic relief but causing a severe side effects on long-term prescription and latter also having a proven effectiveness but having availability and ethical problems Embryonic stem (ES) cells have several characteristics suitable for this purpose. To investigate a possibility of using ES cells as a carrier of therapeutic gene(s), human ES (hES, MB03) cells were transfected with cDNAs coding for tyrosine hydroxylase (TH) in pcDNA3.1 (+) and the transfectants were selected using neomycin (250 $\mu /ml$). Expression of TH being confirmed, two of the positive clone (MBTH2 & 8) were second transfected with GTP cyclohydrolase 1 (GTPCH 1) in pcDNA3.1 (+)-hyg followed by selection with hygromycin-B (150 $\mu /ml$) and RT-PCR confirmation. By immune-cytochemistry, these genetically modified but undifferentiated dual drug-resistant cells were found to express few of the neuronal markers, such as NF200, $\beta$-tubulin, and MAP2 as well as astroglial marker GFAP. This results suggest that over-production of BH4 by ectopically expressed GTPCH I may be involved in the induction of those markers. Transplantation of the cells into striatum of 6-OHDA- denervated PD animal model relieved symptomatic rotational behaviors of the animals. Immunohistochemical analyses showed the presence of human cells within the striatum of the recipients. These results suggest a possibility of using hES cells as a carrier of therapeutic gene(s).

• 한국초지조사료학회지
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• 제26권4호
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• pp.193-198
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• 2006

유용유전자 도입을 통한 신품종 오차드그래스를 개발할 목적으로 Agrobacterium을 이용한 효율적인 형질전환 체계를 확립하였다. 오차드그래스 성숙종자 유래의 캘러스를 standard binary vector인 pIG121Hm을 가지고 있는 Agrobacterium을 이용하여 감염시킨 후 공동배양하여 형질전환 시켰다. Agrobacterium을 이용한 형질전환에 있어서 중요한 인자로 작용하는 AS 첨가와 오차드그래스 품종에 따른 캘러스의 형질전환 효율의 차이를 GUS 유전자의 발현정도로 조사하였다. 'Roughricer' 품종의 형질전환 효율이 가장 우수하였으며, Agrobacterium 감염시에 접종배지와 공동배양배지에 $200{\mu}M$의 AS를 첨가해 주었을 때 형질전환 효율이 증가하는 것으로 나타났다. 50 mg/L의 hygromycin이 첨가된 선발배지에서 살아남은 캘러스로부터 정상적인 식물체가 재분화 되었으며 이들 형질 전환체에 대한 GUS 염색과 PCR 분석을 실시한 결과 발현벡터의 T-DNA 영역이 형질전환식물체의 genome에 성공적으로 도입되었음을 확인할 수 있었다. 본 연구를 통하여 확립된 효율적인 형질전환시스템은 환경스트레스 내성 신품종 오차드그래스의 개발에 유용하게 이용될 수 있을 것이다.

• 한국식품과학회지
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• 제43권1호
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• pp.1-5
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• 2011

본 연구에서 개발된 시험법은 고감도를 가지고 선택성이 뛰어난 LC/MS/MS를 이용함으로서 한번의 시료 전처리와 동시 분석을 통하여 아미노글리코사이드계 항생제 5종의 잔류량 분석을 가능케 하였다(15,16). 개발된 시험법은 CODEX의 가이드라인에 따라 검량선의 직선성, 회수율, 정성한계 및 정량한계, 정확성 및 정밀성 등을 고찰하여 시험법의 실효성을 검증하였다. 확립된 시험법을 이용하여 돼지고기, 닭고기, 쇠고기 등 총 250건을 분석한 결과 5건이 검출되었으며 검출율은 2%로서 검출된 양은 모두 각각의 잔류허용기준보다 낮은 수준이었으나 한 시료에서 겐타마이신과 디하이드로스트렙토마이신이 동시 검출되었다. 이 결과는 여러 종류의 항생제들을 동시에 처방하고 있다는 사실을 입증하고 있다. 그러나, 기기분석을 이용하여 아미노글리코사이드계 항생제의 잔류량 실태조사 결과 검출율 및 검출량이 낮은 안전한 수준이었다.

• 한국가축번식학회지
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• 제27권1호
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• pp.25-34
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• 2003

인체 트롬보포이에틴(hTPO)은 megakaryopoiesis 과정에 주요한 역할을 하는 사이토카인이다. 따라서 이러한 트롬보포이에틴을 유선조직에서 직접적으로 발현시키기 위하여 소 베타 카제인 프로모터, 인체 트롬보포이에틴 cDNA 및 네오유전자로 구성된 발현벡터를 구축하였다. 소 귀조직 세포로부터 유도된 섬유아세포에 lipoffctamine을 이용하여 발현벡터(pBT-L n대)의 삽입을 유도하였다. G4l8 저항성을 지닌 세포의 콜로니 형성을 유도하기 위하여 2주 이상 배양을 실시하였다. 형질전환 콜로니는 PCR에 의해 동정하였으며, 이들 콜로니를 핵치환 전까지 계속적으로 증식을 유도하였다. 형질전환 세포에 의해 재구성된 난자는 전기적인 융합과 calcium ionophore와 6-DMAP를 이용한 활성화를 실시하였으며, 체외에서 7일간 배양을 실시하였다. 총 35개의 콜로니를 PCR에 의해 분석한 결과, 이 중 29(82.9%)개가 형질전환된 콜로니였다. 형질전환된 세포로 재구성된 난자의 난할율 및 배반포로의 발달율은 65.1%와 23.8%로 나타났다. 형질전환된 세포로 재구성된 난자로부터 발달한 29개의 배반포 중 27개가 형질전환으로 확인되었다. 따라서 이러한 결과들은 형질전환 소 수정란을 형질전환된 세포를 이용한 체세포 복제 기법을 통해 효과적으로 생산할 수 있다는 것을 제시하고있다.

• Journal of Animal Science and Technology
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• 제53권3호
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• pp.227-235
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• 2011

A total of 96 crossbred weanling barrows aged 21 days were randomly allocated to 32 pens of a new nursery to investigate the effects of antibiotics, phytogenics, and probiotics on intestinal growth and development. The animals were fed a set of three-phase basal diets containing 0.3% zinc oxide (CON) or the basal diets supplemented with 353 ppm of a combination of tiamulin, neomycin, chlortetracycline, and oxytetracycline (ANTI), 75 ppm triterpenoid saponin plus 150 ppm mixed saccharides (HERB; Sacchapin$^{(R)}$), or $1{\times}10^7$ brewer's yeasts plus $8{\times}10^7$ spores of each of Bacillus licheniformis and Bacillus subtilis per kilogram feed (PROBIO; Yeasture Plus 2B$^{(R)}$) for five weeks. Thirty-two pigs representing as many pens were slaughtered at the end of the feeding trial, after which morphological measures and digestive enzyme activities of intestinal mucosa were determined. Weight gain and gain:feed of the pigs were not affected by the dietary treatments (TRT) during the overall feeding trial. Total intestinal length was greater in PROBIO than in ANTI (P<0.05). Wet mucosa weight of the duodenum was not affected by TRT. However, jejunal mucosa weight was greater in PROBIO than in any other group sum of mucosa weights of the duodenum and jejunum was greater (P<0.05) in PROBIO than in ANTI and HERB. The height and width of duodenal villus were not affected by TRT, but crypt depth decreased (P<0.05) in response to HERB and PROBIO vs CON. Specific activities of alkaline phosphatase, sucrase, maltase, lactase, and leucine aminopeptidase in the duodenum and jejunum were not changed by TRT. In conclusion, results suggest that the present dietary treatments have no effects on growth performance of weanling pigs and that of PROBIO enhances intestinal growth and development under a clean experimental setting.

• 한국어병학회지
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• 제10권2호
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• pp.153-164
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• 1997

양식넙치에 분리한 Yersisnia sp. 의 일부 특성과 병원성을 조사하였다. 넙치의 입주변 및 체표에 궤양을 유발한 원인균의 생화학적 생물물리학적 특성을 조사한 결과 이들 균은 Yersisnia sp. (KF-1)로 동정 되었다. 이들 분리균주의 발육 최적 pH는 9.0이었고, 최적 NaCl농도는 1% 이었다. Yersinia sp. (KF-1)의 전체세포를 SDS-PAGE로 분석한 결과 세포를 구성하고 있는 단백질의 분자량은 14.0-100.6kd로써 총 28개의 peptide 밴드로 구성되어 있으며, 32.8kd의 분자량을 갖는 밴드가 주밴드로 생각된다. 병원성 시험에서 KF-1을 $1.0{\times}10^7$cfu/fish 감염시킨 시험구에서 감염 60시간후에 10마리중 9마리가 폐사되었으며, $1.0{\times}10^7$cfu/fish를 감염시킨 시험구에서는 감염 60시간후에 5마리가 폐사되어 $LD_{50}$은 $1.0{\times}10^7$cfu/fish로 추정되었다. 항생제 감수성 시험에서 KF-1은 chloramphenicol, gentamycin, kanamycin, neomycin, streptomycin, pefloxacin에 감수성을 나타냈고, erythromycin에는 중등도였으며, ampicllin, cephalothin, sulfamethoxazole/trimethoprim, tetracycline, vancomycin에는 저항성을 나타냈다.