Emergences of LH Surge Affected by Different Progesterone Levels in Ovariectomized Goats

김승준 한국임상수의학회 2014 한국임상수의학회지 Vol.31 No.1

The purpose of the present study was to determine the priming effects of progesterone that affect theemergence of LH surge mode secretion by three different progesterone levels. In previous studies, we have shownthat LH surge occurred in follicular levels of progesterone, whereas there was no surge mode secretion of LH andFSH in either the subluteal or luteal levels of progesterone. In this study, the hypothesis was that the priming effectsof progesterone on the timing of the LH surge induced by exogenous estradiol are same between subluteal and luteallevels of progesterone. Long-term ovariectomized Shiba goats that had received implants of estradiol capsules (Day0) and three different progesterone silastic packet inducing follicular, subluteal and luteal levels of progesterone weredivided into three groups such as non-P, low-P and high-P group. Blood samples were collected daily throughout theexperiment for the analysis of gonadal steroid hormone levels. On Day 7, all devices of progesterone packets wereremoved but estradiol capsules were maintained during the experiment, and blood samples were collected at 1 hr intervalfor 12 h from the time of progesterone removals to determine peripheral changes of estradiol and progesteroneconcentration. Then all animals were infused estradiol on the Day 7 after 13 h from the removals of progesteronedevices with a peristaltic pump into jugular vein at a rate of 3 μg/h for 36 h. For analysis of peripheral LH and estradiolconcentration, blood samples were collected via another jugular vein at 2 h intervals for 52 h (from 4 h before thestart of estradiol infusion to 48 h after the start of estradiol infusion). In all animals of the three groups treated withestradiol infusion, an LH surge was expressed but the peak time of LH surge was different. This time interval fromestradiol infusion until the peak of LH surge was gradually and significantly extended by the different levels ofprogesterone treated before estradiol infusions in the three groups.

Structural Stability of Cable-stayed Bridges

김승준,원덕희,이기세,강영종 한국강구조학회 2015 International Journal of Steel Structures Vol.15 No.3

This paper presents an investigation of the structural stability of cable-stayed bridges based on nonlinear analysis. In general, girders and masts of cable-stayed bridges are always subjected to compressive forces due to pre-tensioned stay cables. Cablestayed bridges exhibit various geometric nonlinearities, such as the cable-sag effect, beam-column effect of girders and masts, and large displacement effect. In this study, the characteristics of the structural stability of cable-stayed bridges are investigated. Because of various geometric nonlinearities, nonlinear finite element analysis should be performed for stability analysis instead of conventional eigenvalue analysis. Furthermore, the initial shape analysis should be performed prior to live load analysis in order to consider the dead load condition rationally. A two-step analysis method, developed based on the theory of nonlinear finite element method, is presented in this study for stability analysis under live load cases. An intensive series of parametric studies is subsequently performed using three-span cable-stayed bridges. The main buckling modes are classified depending on the location of the critical members. Also, the effects of cable arrangement, girder-mast stiffness ratio, area, and the number of cables on the structural stability are extensively investigated.

Epigenetic Regulation of miR-22 in a BPA-exposed Human Hepatoma Cell

김승준,유소연,윤효정,이승용,윤종필,황승용 한국바이오칩학회 2015 BioChip Journal Vol.9 No.1

Bisphenol A (BPA), an widely used environmentalchemical, is encircled to human life. However,we generally do not know whether or not it cancause negative health effects. One of the representativeepigenetic changes that inhibit gene expression isDNA methylation, which has been very well studied inassociation with cancer and development. Gene functionis changed by DNA methylation; however, its geneticcode does not change. Our study hypothesizedthat a post-transcriptional change in DNA occurs due toexposure to BPA. These changes then cause regulationof microRNA and gene expression. To identify thesesuccessional regulations, we conducted microarraybasedassays. For validation, also we conducted bisulfitesequencing, quantitative real-time PCR, miRNAinhibitor assay, and Western blotting. We found 1,751hypo-methylation changed regions, and several micro-RNA had included methylated-regions. miR-22 wasalso hypomethylated (chr17:1563947-1564031) byBPA-exposure, and expression of miR-22 was up-regulatedin an miRNA array and real-time PCR. miR-22 has been reported to inhibit estrogen signaling bydirect targeting of the estrogen receptor alpha mRNA. Taking notice of this point, we analyzed gene expressionprofiles that included its predicted targets. In thepresent study, we found the cause of hypomethylationof miR-22 and negative regulation of its apoptosisrelatedtarget gene expression by BPA-exposure. Theseresults suggests that BPA can alter sequential genomicappearances in HepG2 cells, a potentially affectionof BPA toxicity. Also, the results of our study supportthat toxicology study need to integrated analysisof array-based assays for help in understanding of themolecular action of environmental toxicants.

의과대학생의 성별(gender)이 전공 과목 선택에 미치는 영향

김승준 연세대학교 의과대학 의학교육학과 2004 의학교육논단 Vol.6 No.1

아토피피부염에서 혈청 가용성 CD30 측정의 의미

김승준,이은호,심정연,정혜림,박문수,금동혁 대한 소아알레르기 및 호흡기학회 2001 Allergy Asthma & Respiratory Disease Vol.11 No.4

기관지천식환자의 기도재구성과 기관지폐포세척액 세포의 transforming growth factor-β1 및 basic fibroblast growth factor 발현과의 관계

김승준,이숙영,박용근,김명훈,김석찬,권순석,김영균,김관형,문화식,송정섭,박성학 대한천식알레르기학회 2002 천식 및 알레르기 Vol.22 No.4

트랙터 부착형 다기능 작업기의 비용 및 포장능률 비교를 통한 경제성 분석

김승준,남주석,장문경 강원대학교 농업생명과학연구원 2022 농업생명환경연구 Vol.34 No.2

In this study, an economic analysis of the cost and field capacity was conducted to prove the validity of developing and distributing a tractor-mounted multi-working machine. The cases of using a multi-working machine and individual working machines were compared. The results showed that the total hourly cost of the multi-working machine was 308,805 KRW. Compared with individual working machines, the tractor-mounted multi-working machine can save 53.5% of the total hourly cost. The field capacity for the multi-working machine was 12 ares/hour. This is 60.0% higher than that of individual working machines. The cost per 10 ares working area was calculated using the hourly total cost and field capacity. The cost per 10 ares working area for the multi-working machine is 257,337 KRW, meaning that the multi-working machine can save 71.0% of the cost compared with individual working machines. Therefore, it is concluded that the economic validity of the multiworking machine is high.

투석을 시작하는 말기 신부전증 환자에서 혈관 내피세포의 기능이상

김승준,이정은,유동은,오형중,이한성,박선영,문성진,김동기,한대석,강신욱 대한신장학회 2006 Kidney Research and Clinical Practice Vol.25 No.6

Background : Patients with renal failure have increased cardiovascular risk due to accelerated atherosclerosis. Endothelial dysfunction (ED) appears to be an important initiating event in the process of atherogenesis. ED has been reported in patients receiving hemodialysis and peritoneal dialysis. However, there has been no study on ED in Korean ESRD patients starting dialysis treatment. In this study, ED was assessed in patients starting dialysis treatment and the risk factors of ED were analyzed. Methods : Among the patients diagnosed as terminal-stage renal disease (ESRD) and started dialysis treatment at Severance Hospital of Yonsei University College of Medicine from January, 2005 to December, 2005, 35 patients (ESRD group) (51.7±12.6 years-old, M:F=22:13) underwent Doppler ultrasonography to have their endothelial functions assessed. Flow-mediated dilation (FMD) was used as an index of ED. For the control group, 33 hypertensive patients (55.2±11.4 years-old, M:F=17:16) with normal renal function were selected and FMD was also measured. Results : FMD was significantly reduced in the ESRD group compared to the control group (3.8±1.9 vs. 4.9±2.4%, p<0.05). When the ESRD group was divided into either DM or non-DM group according to DM status, there was a significant difference in FMD between the two groups (DM, 3.1±1.9%; non-DM, 4.4±1.9%, p<0.05). In the ESRD group, FMD was inversely related to systolic blood pressure, mean arterial pressure, pulse pressure, and DM duration (p< 0.05). Conclusion : ED was already present in patients at the time of starting dialysis treatment and was more severe in the DM compared the non-DM patients.

터널 막장면 RMR 가중평가 현장관리 방안

김승준,안성호,김홍무,정창훈,김국한 한국지반공학회 2021 지반 : 한국지반공학회지 Vol.37 No.2

혈소판 농축액이 이식된 지방의 생존에 미치는 영향

김승준,최원일,이병일,박승하,박철,구상환 대한성형외과학회 2007 Archives of Plastic Surgery Vol.34 No.3

Purpose: Platelet-rich plasma(PRP) contains protein growth factors, which are actively secreted by platelets to promote wound healing. However, it is not clear whether the injection of PRP into the autologous fat grafts increases the survival rate and the degree of angiogenesis.Methods: New Zealand White rabbit ears were injected fat with PRP, saline, insulin or isoproterenol (n=8/each group) for observation of the survival and degree of angiogenesis of the injected fat. The volume of the harvested fat and the degree of angiogenesis from dorsum of rabbit ears were evaluated 4, 8, and 12 weeks after the autologous fat graft. The degree of angiogenesis was measured with microvascular density (MVD) counts.Results: The volume of harvested fat decreased in a time-dependent manner after autologous fat grafts, but the decrease rate in volume of harvested fat was slower in PRP-injected group compared to that of other control groups. The difference in the volume of the harvested fat between PRP-injected group and other control groups became significant from 4 weeks after the autologous fat graft, and was maintained up to 12 weeks. However, there was no significant difference between PRP-injected group and insulin-injected group 8 and 12 weeks after the autologous fat graft. On the contrary, MVD counts increased in a time-dependent manner after autologous fat grafts. The MVD counts were significantly higher in PRP-and insulin-injected groups than in other control groups from 4 weeks after the autologous fat graft, and these differences were maintained up to 12 weeks. There was no correlation between mean platelet numbers and the volume of harvested fat.Conclusion: The present study demonstrates that PRP-injection into autologous fat grafts increases the survival rate and the degree of angiogenesis. Thus, PRP injection with autologous fat grafts would be a promising tool for maintaining the volume of the grafted fat.