The number of CT gradually tends to increase, but radiation exposure includes higher exposure dose of patients than other test methods as the rate of 67% in the whole radiology tests. Exposure dose of patients has increased due to it and the second exposure has been done by scattered rays of other organs except for test sites. Especially, special shielding has not been done in gonad which is very sensitive to radiation in brain and chest CT. So this study tries to research the second exposure dose of the gonad and how to shield it in Chest CT which does not include it. It was intended for 20 male adults who are 30 years old and conduct chest CT. SIEMENS’s SOMATOM DEFINITION AS* was used as CT equipment. For the scanning conditions, The tube voltage is 120kv, the tube current is 90mAs, and the slice thickness is 3mm as the general chest CT conditions. CHIYODA TECHNOL CORPORATION’s FGD1000 was used as Glass dosimeter (PLD). A lead pad of 0.25mmPb was produced as the shielding board. For the research method, the shielding rate was compared by measuring exposure dose of the gonad before and after shielding and the usefulness of the shielding board was evaluated. The average exposure dose of symphysis pubica before shielding was 280.5μGy and the average exposure dose of coccyx was measured as 151.5μGy. The average exposure dose of symphysis pubica after shielding the gonad with a lead pad of 0.25mmPb was 42μGy and the average exposure dose of coccyx was measured as 41μGy.

In mammals, male and female germline stem cells are derived from primodial germ cells. Despite many efforts to identify stem cells from gonads, there has been little successe to identify germline stem cells yet. In this study, we isolate and characterized porcine germline stem cells using only stem cell markers that are prevalently expressed in various tissues. Gonadal cells derived from both male and female formed colonies and showed AP activities and different lectin binding properties. Pluripotency of germline stem cells was also identified by positive signals against putative stem cells markers such as SSEA-1 and SSEA-3. In addition, nestin was also found in primary gonad cells that have a similar morphology to the AP-positive cells. The nestin expression suggests that the germline stem cells may have similar expression of the prevalent stem cell markers found in other tissues. The demonstration of nestin expression together with pluripotent cell markers calls further investigation of the possible differentiation of nestin-positive cells into neurons.

위장조영검사는 X선을 사용하는 검사로 검사 부위 외의 다른 장기의 피폭이 발생한다. 위장조영검사에 서 갑상선, 수정체, 유방, 생식선 등 생물학적으로 방사선감수성이 상대적으로 높은 표적장기가 주변에 분포되어있기 때문에 방사선 피폭에 대한 방어를 하는 것이 중요하다. 장기별 측정 깊이의 선택이 가능한 전신 팬톰을 제작하고 안구, 갑상선, 유방, 생식선의 방사선 피폭선량을 측정하였다. 투시만 시행하였을 경우 수정체, 갑상선, 유방, 생식선의 평균 피폭선량의 감소는 62.2%로 나타났고, 투시와 Spot 촬영을 동시에 시행하였을 경우 수정체, 갑상선, 유방, 생식선의 평균 피폭선량의 감소는 59.0%로 나타났다. 따라서 위장조영검사 시 수정체, 갑상선, 유방, 생식선의 차폐가 이들의 피폭선량 감소에 효과가 있었다는 것을 확인할 수 있었다. 제작한 인체 팬톰은 인체에 위치한 장기에 해당하는 높이를 조절할 수 있기 때문에 심부선량 측정에 사용될 수 있을 것이다.

The marine medaka, Oryzias dancena is a suitable sample as a laboratory animal because it has a small size and clearly distinguishes between female and male. Data on the growth and maturity of the diploid and triploid sea cucurbit species suitable for laboratory animals are very useful for studying other species. Triploidy was induced in the marine medaka by cold shock treatment (0°C) of fertilized eggs for 45 min, applied two minutes after fertilization. The diploid and triploid male fish were larger than their female counterparts (P<0.05), and the concentrations of thyroid stimulating hormone (TSH) and thyroxine (T4) were higher in the induced triploids over 1 year (P<0.05). In both the diploid and tri-ploid groups the concentrations of TSH and T4 were higher in the male fish than in the females (P<0.05), while the testo-sterone and estradiol-17ß concentrations in the induced triploids were lower than in the diploids (P<0.05). The gonadosomatic index (GSI) of the triploid fish was lower than that for the diploids, and the GSI for females in each ploidy group were higher than that for the males. For both groups the GSI was highest at 4 months of age, and decreased thereafter to 12 months. Analysis of the gonads of one-year-old triploid fish suggested that the induction of triploidy probably causes sterility in this species; this effect was more apparent in females than in males.

통상적으로 골반 정면검사 및 고관절 정면검사 시 유아기의 남아보다 여아의 경우 해부학적으로 생식선 차폐를 하기 어렵고 검사 시 차폐체 위치의 정확한 기준점이 없었다. TDP, SD, ISP, IAD,1CDP. 2CDP의 골반지표를 계측하여 정확한 생식선 차폐체를 제작하는데 기초자료로 제공하고자 본 연구를 시행하였다. 신장별로 분석한 결과는 TDP가 70이상-80미만과 110이상-120미만에서 약 30mm, SD는 약 13mm, ISP는 약 19mm , IAD는 약 20mm ,1CDP는 약 2mm. 2CDP는 약 7mm 차이가 나타났으며 통계적으로 유 의하였다.(p<0.05) 연령별로 분석한 결과는 TDP가 2이상-3미만과 6이상-7미만에서 약 17mm, SD는 약 10mm, ISP는 약 12mm, IAD는 약 16mm, 2CDP는 약 3mm 차이가 나타났으며 통계적으로 유의하였 고 1CDP는 약 1mm정도로 거의 차이가 나타나지 않았고 통계적으로 유의하지 않았다.(p>0.05) 체중별로 분석한 결과는 TDP가 10미만과 20이상에서 약 28mm, SD는 약 14mm, ISP는 약 11mm, IAD는 약 20mm, 1CDP는 약 3mm, 2CDP는 약 8mm 차이가 나타났으며 통계적으로 유의하였다.(p<0.05) 이상의 결과에서 볼 때 유아기 여아의 골반지표 계측치는 차폐체 제작의 기준치로 사용 될 수 있을 것이며, 특히 IAD는 차폐체 위치의 기준점을 제시할 수 있다. 그리고 유아기 여아의 골반지표는 신장, 연령, 체중과 밀 접한 상관관계가 있었으며 통계학적 차이분석 결과에서 보듯이 정확한 난소차폐를 하기 위해서는 각각의 신장, 연령, 체중별로 생식선 차폐체를 제작하고 사용해야 할 것이다.

본 연구는 생쥐의 난소 및 정소 조직에서 발달 단계에 따라 나타나는 일주기성 clock유전자의 발현과 단백질의 발현 양상을 알아보고자 하였다. 생쥐의 난소 및 정소에서 일주기성 변화와 연관된 유전자(Period1(Per1), Period2(Per2), Period3(Per3), Cryptochromel(Cry1), Cryptochrome2 (Cry2), Clock, Bmall)와 시교차 상핵에서 분비되어 표적 조직 또는 기관으로 전달되는 물질로 알려진

The hypothalamic peptide GnRH plays a central role in the regulation of the mammalian reproductive axis. Recent studies suggested that GnRH stimulates or inhibits the ovarian steroidogenesis and gametogenesis directly. Our previous report indicated that GnRH gene is expressed in adult rat ovary as well as in hypothalamus and that the expressed GnRH may induce the follicular atresia and apoptosis of ovarian granulosa cells in rat. Therfore, we studied whether GnRH gene is expressed in the mouse fetal ovary, when the germ cells are degenerating by apoptosis during gonad diffeerentiation. Mouse fetal gonads were obtained on the 12, 15,18 and 20th day of gestation from the mother mice superovulated (10 IU PMSG and 10 IU hCG) and mated. The morphological changes of fetal ovaries were examined histochemically by hematoxylin-eosin staining. The fetal sex was confirmed by PCR methods for sexing. RT-PCR methods were used to examine the expression of GnRH gene and the sex steroid hormones were determined by conventional radioimmunoassays. The levels of estradiol (E) and progesterone (P) were increaseduntil 18th day of gestation and then E was decreased just before parturition. The morphological changes of fetal gonadal tissue sections showed the ovarian development and coincided with the result of PCR analysis for sexing using ovary- or testis- specific oligonucleotide primers. Immunoreactive GnRH in placenta was decreased gradually until the end of gestation but fetal brain and ovarian GnRH were increased. The level of GnRH gene expression was increased during fetal ovarian development from 12 till 18th day and decreased suddenly on 20th day just before birth. From these results, it is suggested that ovarian GnRh may play a regulatory role on the germ cell differentiation of fetal ovary.