• Korean Journal of Veterinary Research
• /
• v.34 no.4
• /
• pp.735-744
• /
• 1994

Catheters were placed into the external jugular veins of immature female rats. On the following day (day 28 of age), the animals were injected subcutaneously with pregnant mare serm gonadotropin(PMSG): 4IU(control) or 20IU(superovulation). Each animal was sequentially bled at Ohr and 12hr and subsequently at 6hr intervals until sacrifice at 72hr after PMSG. The superovulatory dose of PMSG significantly(P<0.05) increased the ovulatory response by 4.0 fold above controls. On the other hand, superovulated oocytes displayed considerably different stages of meiotic maturation: prophase I (14.7%), anaphase I (36.2%), telophase I (10.3%), metaphase I/II (32.4%), while in control rats a majority of the oocytes examined(94.0%) consistently showed a metaphase II configuration. Serum luteinizing hormone(LH) levels were determined by RIA. Both groups exhibited a similar time relationship with two distinct peaks: an initial slight rise at 0-18hr and a second sharp rise at 54-60hr. However, there was a marked change in the magnitude of LH levels between the two groups. In superovulated animals, prior to the second peak, overall LH levels were significantly(P<0.001) higher than controls. In contrast, at the peak occurring at 60hr, LH concentrations were significantly(P<0.001) reduced by 54% below that of control. Additionally, a maximum increase of mean ${\Delta}LH$ between two peaks was much less in superovulated as compared to control rats. The initial prolonged elevation of serum LH before 54hr in superovulated rats was found to result from actual cross-reaction of the injected PMSG with LH antibody in the assay, while a precipitous second elevation between 54hr and 60hr resulted primarily from an endogenous LH surge. This study clearly defines time-course features of serum LH in PMSG-treated rats. The overall results indicate that, following superovulatory treatment with PMSG, the increased ovulatory response is primarily associated with PMSG-derived intrinsic gonadotropin, and that the recovery of immature or asynchronously mature oocytes at ovulation may reult from the circulatory alteration of LH activity characterized by an initial prolonged elevation of serum LH and its subsequent attenuation.

• Journal of Chest Surgery
• /
• v.32 no.1
• /
• pp.1-4
• /
• 1999

Background: The transplantation of organs between phylogenetically disparate or harmonious species has invariably failed due to the occurrence of hyperacute rejection or accerelated acute rejection. But, concordant cardiac xenograft offer us an opportunity to study xenotransplantation in the absence of hyperacute rejection. Current therapeutics for the prolongation of survival of rodent concordant xenotransplantation are not ideal with many regimens having a high mortality rate. Cyclosporine A & Mycophenolate Mofetil are new immunosuppresive agent which has been shown to be effective at prolonging survival of allograft, as purine synthesis inhibitor. Material and Method: We used white mongrel rats as recipient and mice as donor, divided 4 groups(n=6), control group(Group 1) has no medication or pretreatment, Group 2 has splenectomy as pretreatment 7∼10 days before transplantation, Group 3 has Cyclosporine A treatment group, Group 4 has combined treatment of Cyclosporine A & Mycophenolate Mofetil(RS 61443). We compared survival time. Reuslt: We can't find significant difference of survival time between each groups. Conclusion: We concluded that rejection of cardiac xenograft was different from rejection of allograft, and new immunossuppresive Agent(Mycophenolate Mofetil, Cyclosporine A) was not effective for prolongation of survival time after cardiac xenograft.

• Tuberculosis and Respiratory Diseases
• /
• v.45 no.1
• /
• pp.99-106
• /
• 1998

Background: Bronchial asthma is a complex disease, which is characterized by spontaneous exacerbations of airway obstruction and persistent bronchial hyperresponsiveness. Animal models have fallen short of reproducing the human disease, particularly in mimicking the spontaneous and persistent airflow obstruction that characterized in asthma. In animals, airflow obstruction is usually assessed by measuring airflow resistance during tidal breathing under such invasive technique as tracheostomy and anesthesia. A noninvasive technique for measuring pulmonary function in small animals is needed to evaluate long-term changes in lung function during the course of experimentally produced disease without sacrificing the animal. Purpose: The purpose of this study was to evaluate early bronchoconstrcition after allergen challenge and airway responsiveness (AR) to inhaled methacholine in nonanethetized, unrestrained guinea pigs. Method: Guinea pig model of asthma was sensitized by subcutaneous injection with ovalbumin and challenged by inhalation of aerosolized ovalbumin(1% wt/vol ovlabumin). Airflow obstruction of conscious guinea pig was measured as specific airway resistance (airway resistance $\times$ thoracic gas volume). Airway resistance and thoracic gas volume of conscious guinea pig were assessed by body plethysmography before challenge and at regular intervals for as long as 30 minutes after challenge. AR to aerosolized methacholine of asthma group was compared with that of control group in body plethysmography. Result: Asthma model<> developed in 13 (65%) among 20 guinea pigs, in which early responses occurred in the airways after the exposure to inhalation with ovalbumin. Airway challenge with ovalbumin caused increase in specific airway resistance, which peaked at 6 minutes and amounted to a $231.5{\pm}30.4%$ increase from baseline. AR to aerosolized methacholine of asthma model increased significantly compared with control group. Conclusion: These results have showed a useful animal model to evaluate early bronchoconstrcition after allergen challenge and airway responsiveness in nonanethetized, unrestrained guinea pigs.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.594-594
• /
• 2013

금속이 첨가된 타이타니아 물질은 밴드갭이 감소해 자외선보다 파장이 긴 가시광 영역에서도 광촉매 반응을 나타낸다. 바나듐이 도핑된 타이타니아를 sol-gel법으로 제조하여 가시광과 자외선 환경에서 methylene blue의 감소량을 측정해 촉매특성평가를 하였다. 기존 상용 타이타니아(Degussa, P25)를 대조군으로 특성을 평가한 결과 가시광 영역에서 초기 반응 속도가 3배 이상 빨라짐을 확인하였다. UV-vis를 사용해 optical band gap을 측정한 결과 밴드갭이 감소함을 확인할 수 있었다. 도핑이 끝난 타이타니아 전구체 물질을 AAO template 위에 코팅한 후 sodium hydroxide로 template을 제거 후 나노그물을 제작하였다.

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 2002.11a
• /
• pp.311-315
• /
• 2002

Polyurethane 발포체는 우수한 단열 및 흡음특성 그리고 반응물질인 polyol과 isocyanate의 성분 및 배합비에 따라 여러가지 제품군으로 특성 설계가 가능하여 LNG 저장탱크, LNG 유조선의 cryogenic insulator, 육상 및 해상용 냉동 및 냉장시설물, 가전제품, 건축단열판넬 등에 널리 사용되고 있다. 그러나 난연성의 결여로 화재 발생시 급격한 연소반응과 유해가스 발생을 동반하여 화재안전 및 건강보건상 중대한 단점을 가지고 있다. 본 연구진은 PU발포체의 물성개선을 통한 난연특성 연구의 일환으로서 montmorillonite, hectorite, vermiculite의 layer silicate를 urethane 원료물질과 혼성발포 공정을 통해 난연복합체를 제조하여 UL94V, LOI, Morphology 등의 시험을 수행하였다.(중략)

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.29 no.1
• /
• pp.111-115
• /
• 2000

This study was to investigate antiallergic contact hypersensitivity of the polyphenol fractons isolated from persimmon leaves (Diospyros kaki folum). The result of the allergic contact dermatitis is a common skin disease resulting from specific immunologic sensitization due to topically applied allergens. Here the contact hypersensitivity was assayed and obdominal skin morphological changes including mast cells were examined. At contact hypersensitivity assay, less right ear swelling occured in the polyphenol fraction I, II and III groups compared to the control group. The number of mast cells was significantly decreased in the sample groups than the control group.

• The Korean Journal of Nuclear Medicine
• /
• v.35 no.5
• /
• pp.313-323
• /
• 2001

Purpose: The purpose of this study was to search activated genes that could be related to radiation adaptive response (RAR) induced by low-level radiation from $^{99m}Tc$ in human cell lines. Methods: We used gene discovery array (GDA) and representational difference analysis (RDA) methods. $^{99m}Tc$-pertechnetate was added to $2{\times}106/mL$ NC-37 cells (human lymphoblastic cells) to make concentrations ranging from 148 MBq/mL to 148 Bq/mL by serial 10 fold dilutions. After 44 hours, 2 Gy gamma irradiation was given to them using a Cs-137 cell irradiator. Results: As compared to the control (Con) group to which no $^{99m}Tc$ was added, those cells to which 148 and 14.8 KBq of $^{99m}Tc$ were added showed significantly lower damage to chromosomes, which was evaluated by metaphase analysis. Cells with 148 KBq $^{99m}Tc$ (T148 group) showed most significant protection. Activated genes in the T148 group as compared to Con group were evaluated by GDA and GDA methods. GDA revealed genes of casein kinase 2 (CK2) beta chain, immunoglobulins (lg), human leukocyte antigen (HLA)-B, and two novel genes. Twenty RAR related clones were selected by RDA method. The size of those genes was from 234 to 603 base pairs. Conclusions: RAR was induced by low dose irradiation from $^{99m}Tc$ in NC-37 cell lines. Genes related to the response included CK2, lg, HLA-B in human lymphoblastic cell lines.

• Clinical and Experimental Pediatrics
• /
• v.51 no.11
• /
• pp.1165-1171
• /
• 2008

Purpose : This study aimed to identify the true extent of non-responsiveness in full-term infants born from HBsAg-negative or HBsAg-positive mothers and vaccinated against hepatitis B virus (HBV) at 0, 1, and 6 months of age and to evaluate the effect of revaccination among non-responders. Methods : The study included 716 full-term infants born in 2004-2007. Of 716, 662 infants (A group) were born to HBsAg-negative mothers and 54 infants (B group: 50, except HBsAg-positive infants) were born to HBsAg-positive mothers. All infants were administered DNA recombinant vaccines at 0, 1, and 6 months of age. B group infants received hepatitis B immunoglobulin at birth. Anti-HBs titers were tested at 7-12 and 9-15 months in A and B groups, respectively. Three revaccination doses were administered to non-responders whose anti-HBs titers were under 10 mIU/ml; revaccinated infants were retested at 1-3 months after last vaccination. The association between HBeAg seropositivity of mother and the failure of HBV immunoprophylaxis was evaluated. Results : The seroconversion rates after primary hepatitis B vaccination were higher in A group (94.1%) than in B group (78%, P<0.001). The seroconversion rates were high in revaccinated infants (A group non-responders: 96.9%, B group non-responders: 87.5%). The failure of HBV immunoprophylaxis was significantly associated with maternal HBeAg seropositivity (P<0.001). Conclusion : The seroconversion rates after primary hepatitis B vaccination were low in B group infants. Revaccination of non-responders in B group was very effective. Therefore, anti-HBs testing and revaccination of B group is very important. Revaccination of non-responders in A group was also very effective. Thus, testing the immune status of infants born to HBsAg-negative mothers even after primary hepatitis B vaccination should be considered. However, to realize this, further studies on the cost-effectiveness of anti-HBs testing in healthy full-term infants are necessary.

• Journal of Chest Surgery
• /
• v.40 no.8
• /
• pp.552-557
• /
• 2007

Background: B-type natriuretic peptide (BNP) is a cardiac hormone that is primarily synthesized by the ventricular cardiac myocytes. Increased plasma BNP levels have been observed in patients suffering with congestive heart failure, ventricular hypertrophy and myocaridits and also during heart transplantation rejection. We investigated the serum BNP level as a predictive marker for rejection after heart transplantation. Material and Method: To test the usefulness of measuring the BNP level in cardiac transplant patients, consecutive blood samplings for BNP, right ventricular endomyocardial biopsies, hemodynamic measurements and transthoracic echocardiogram were all done in 10 such patients between January 2004 and August 2005 at the Department of Thoracic and Cardiovascular Surgery in Asan Medical Center. Two groups were identified with using the median value: the low BNP group (n=28, BNP: ${\le}290$ pg/mL) and the high BNP group (n=29, BNP: >290 pg/mL). We retrospectively analyzed rejection, the ejection fraction, tricuspid regurgitation, left ventricular hypertrophy, the pulmonary capillary wedge pressure and the right atrial pressure between the 2 groups. Result: There were no differences in age, gender, rejection, the ejection fraction, tricuspid regurgitation, left ventricular hypertrophy and the right atrial pressure between the 2 groups (p>0.05). However, a higher pulmonary capillary wedge pressure and a higher mean pulmonary atrial pressure were observed in the high BNP group (p<0.05). Further, BNP has linear correlation with the pulmonary capillary wedge pressure (r=0.590, p<0.001). Using the cut-off value of 620 pg/mL, the BNP predicted a high PCWP (>12 mmHg) with a sensitivity of 83.3% and a specificity of 91.1% (AUC: $0.900{\pm}0.045$, p<0.001). Conclusion: The BNP level after heart transplantation does not show any significant correlation with rejection, yet it might be a predictive marker of ventricular diastolic dysfunction.

• The Microorganisms and Industry
• /
• v.16 no.3
• /
• pp.20-25
• /
• 1990

면역계에는 조력T세포(helper T cell)와는 반대로 면역반응을 억제적으로 조절하는 것이 주 기능인 억제성 T세포(suppressor T cell)가 존배한다는 것이 아려져 있다. 이 억제성 T세포가 존재한다는 개념이 면역학및 임상의학에 준 영향은 매우 지대하여, 앨러지나 자가 면역질환 같은 질병은 억제성 T세포의 결핍으로, 그리고 면역 결핍증같은 질병은 T세포가 지나치게 활성화된 것으로 설명되기에 이르렀다. 한마디로 거의 모든 저하된 면역반응은 억제성 T세포와 연관하여 설명되었다. 그러나 억제성 T세포가 발견된지 근 20년이 되고 그에 관한 논문이 5000여편에 달하는 최근까지도 억제성 T세포 및 이들 세포가 만드는 억제성 T세포 인자에 대한 실체는 정확히 규명되지 못하고 있다. 오히려 억제성 T세포가 조력 T세포처럼 별개의 세포군으로 존재한다는 것을 부인하는 학자도 최근 나오게 되었다.(이 분야의 연구에서 나타난 문제점들이 정리되어 있음). 그러나 억제성 T세포의 존재를 부인하는 학자들도 T세포가 면역 반응의 억제에 관여한다는 사실, 적어도 그 현상 자체를 부인하지는 않았다. 다시말하면, 면역반응이 T세포에 의하여 억제되는 현상은 이미 수 천년의 논문을 통하여 입증되고 있다. 면역반응의 억제에 있어서 억제성 T세포및 억제성 T세포 인자의 역할은 앞으로의 연구를 통해 명확히 규명될 것이며, 정말 억제성 T세포가 있느냐 없느냐 하는 것은 이 총설의 주제가 아니다. 다만 여기서는 조력 T세포도 경우에 따라서는 면역반응의 억제에 관여한다는 최근의 연구결과를 간단히 소개하고자 한다.