• Title/Summary/Keyword: Time Dependent

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Temperature-driven Models of Lipaphis erysimi (Hemiptera: Aphididae) Based on its Development and Fecundity on Cabbage in the Laboratory in Jeju, Korea (양배추에서 무테두리진딧물의 온도의존 발육 및 산자 단위모형)

  • Oh, Sung Oh;Kwon, Soon Hwa;Kim, Tae Ok;Park, Jeong Hoon;Kim, Dong-Soon
    • Korean journal of applied entomology
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    • v.55 no.2
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    • pp.119-128
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    • 2016
  • This study was conducted to develop temperature-driven models for a population model of turnip aphid, Lipaphis erysimi: nymphal development rate models and apterious adult's oviposition (larviparous) model. Nymphal development and the longevity and fecundity of adults were examined on cabbage at six constant temperatures (10, 15, 20, 25, 30, $35{\pm}1^{\circ}C$, 16L:8D). L. erysimi nymphs did not survive at $10^{\circ}C$. Development time of nymphs increased with increasing temperature up to $30^{\circ}C$ and thereafter slightly decreased, ranging from 18.5 d at $15^{\circ}C$ to 5.9 d at $30^{\circ}C$. The lower threshold temperature and thermal constant were estimated as $7.9^{\circ}C$ and 126.3 degree days, respectively. The nonlinear model of Lactin 2 fitted well for the relationship between the development rate and temperature of small (1+2 instar), large (3+4 instar) and total nymph (all instars). The Weibull function provided a good fit for the distribution of development times of each stage. Temperature affected the longevity and fecundity of L. erysimi. Adult longevity decreased as the temperature increased and ranged from 24.4 d at $20^{\circ}C$ to 16.4 d at $30.0^{\circ}C$ with abnormal longevity 18.2 d at $15^{\circ}C$, which was used to estimate adult aging rate model for the calculation of adult physiological age. L. erysimi showed a maximum fecundity of 91.6 eggs per female at $20^{\circ}C$. In this study, we provided three temperature-dependent components for an oviposition model of L. erysimi: total fecundity, age-specific cumulative oviposition rate, and age-specific survival rate.

A study on the perception of landscape through the selection process of Bandopalgyong - eight beautiful scenary in Korea - within Japanese colonial period (일제강점기 반도팔경 선정과정을 통해 본 경관인식)

  • Kim, Hai-Gyeong;An, Kyung-Jin
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.33 no.2
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    • pp.78-88
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    • 2015
  • In the 1920s, the period of cultural governance ruled by Japan, the diverse media were founded and various events were conducted to boost circulation. Under the Japanese colonial period in 1920s, a number of media - newspapers and magazines - were published and often they carried out entertaining events in order to obtain more subscribers. A hobby magazine, Samchunri, for instace, set up a media event to selecting Korea's eight beautiful scenary (Bandopalgyong) for the first edition in 1929. The paper aims to analyse and understand the perception of landscape in 1929 through the media event carried out by Samchunri. In particular, the selection was made by well-known writers within Japanese colonial period 1910 - 1945). The selection process and views from the writers on landscape were analysed; firstly, the selection of Bandopalgyong was carried out by questionnaires to writers in 1929 where Korea is under Japanese colonial rules. The conditions of the selection were unknown; however, the purpose was enlightening the people specially the youngs and introduction of beautiful places in Korea. As a result, views and opinions on Bandopalgyong by the writers were progressed. Secondly, within the Bandopalgyong, the natural landscape areas include Gumgansan(金剛山), Daedonggang(大洞江), Buyeo(扶餘), Gyongju(慶州), Myongsasipri (明沙十里), Haundae(海雲臺), Baekdusan(白頭山), and Choksukru(矗石樓). Those chosen places were not cohesive nor did not have any consistant reasons to be chosen in terms of size and location; however, some writers claimed that there were other places to match the chosen ones and therefore, the selection process was highly dependent on access (i.e. transport). Thirdly, the travelogue on Baekdusan and Nackwhaam(洛花岩) illustrated interesting views on landscape in particular. Baekdusan landscape were described in overlaping with long history and national soul. In the Nackwhaam travelogue, it described 'Buyeo (夫餘) was an ancient capital of Backjae Dynasty and empty place' as well as denying Chosun Dynasty. It was assumed that the two places weren't visited but rewritten with existing literatures. Fourthly, edited by Kim Dong Whan, a travelogue style book, 'Bandosanha' was published in 1941. It did repeat the selection of Bandopalgyong, but this time, it was classified the eight beautiful landscape into two categories; historic/cultural places and natural landscape. This paper was able to analyse and understand the perception of landscape in 1929 through the travelogue of Samchunri. It is an empirical study on the process and perception on Korea landscape under Japanese colonical period by views of the selected writers.

Identification of Chloride Channels in Hamster Eggs (햄스터 난자에서 존재하는 Chloride 통로)

  • Kim, Y.-M.;Kim, J.-S.;Hong, S.-G.
    • Journal of Embryo Transfer
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    • v.19 no.2
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    • pp.101-112
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    • 2004
  • Chloride($Cl^-$) channels play critical roles in cell homeostasis and its specific functions such as volume regulation, differentiation, secretion, and membrane stabilization. The presence of these channels have been reported in all kinds of cells and even in frog oocytes. These essential role of $Cl^-$­ channels in cell homeostasis possibly play any role in egg homeostasis and in the early stage of development, however, there has been no report about the presence of $Cl^-$­ channel in the mammalian oocyte. This study was performed to elucidate the presence of $Cl^-$­ channels in hamster eggs. When allowing only $Cl^-$­ to pass through the channel of the egg membrane by using impermeant cation such as N-methyl-D-glucamine(NMDG), single channel currents were recorded. These channel currents showed typical long-lasted openings interrupted by rapid flickering. Mean open $time({\tau}o)$ was 43${\pm}$10.14 ms(n=9, at 50 mV). The open probability(Po) was decrease with depolarization. The current-voltage relation showed outward rectification. Outward slop conductance(32${\pm}$5.4 pS, n=22) was steeper than the inward slop conductance(10${\pm}$1.3 pS). Under the condition of symmetrical 140 mM NaCl, single channel currents were reversed at 0 mV(n=4). This reversal potential(Erev) was shifted from 0 mV at 140 mM concentration of internal NaCl(140 mM [Na+]i) to ­9.8${\pm}$0.5 mV(n=4) at 70 mM [Na+]i and 11.5${\pm}$1.9 mV at 280 mM [Na+]i(n=4) respectively, strongly suggesting that these are single $Cl^-$­ channel currents. To examine further whether this channel has pharmacological property of the $Cl^-$­ channel, specific Cl­ channel blockers, IAA-94(Indanyloxyacetic acid-94) and DIDS(4, 4'-diisothiocyan ostillben- 2-2'disulfonic acid) were applied. IAA-94 inhibited the channel current in a dose-dependent manner and revealed a rapid and flickering block. From these electrophysiological and pharmacological resluts, we found the novel $Cl^-$­ channel present in the hamster oocyte membrane. The first identification of $Cl^-$­ channel in the hamster oocyte may give a clue for the further study on the function of $Cl^-$­ channel in the fertilization and cell differentiation.

Influence of Hypoxia on Catecholamine Secretion Evoked by DMPP, McN-A-343, Excess $K^+$ and ACh from The Perfused Rat Adrenal Gland (저산소증이 흰쥐 관류부신에서 DMPP, McN-A-343, Excess $K^+$ 및 Ach의 카테콜아민 분비작용에 미치는 영향)

  • Lim Dong-Yoon;Heo Jae-Bong;Park Yoo Han
    • The Korean Journal of Pharmacology
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    • v.31 no.1 s.57
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    • pp.63-74
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    • 1995
  • It has been known that, during hypoxia, the adrenal medulla is activated to release catecholamines (CA) while hypoxia also inhibits high $K^+$ -induced CA secretion in the cultured bovine adrenal chromaffin cells. The present study was attempted to examine the effect of hypoxia on CA secretion evoked by chlinergic stimulation and membrane-depolarization from the isolated perfused rat adrenal glands and also to clarify its mechanism of action. For this purpose, using the isolated rat adrenal glands, the effects of hypoxia on CA release evoked by nicotinic ($N_1$) and muscarinic ($M_1$) receptor agonists, membrane-depolarizing agent, $Ca^{++}$-channel activator, intracellular $Ca^{++}$-releaser and ACh were determined. Experiments were carried out, perfusing Krebs solution pre-equilibrated with a gas mixture of 95% N_2$ and 5% $CO_2$. Hypoxia was maintained for $3{\sim}4$ hours through the experiments. Hypoxia gradually caused a time-dependent seduction in CA secretion evoked by DMPP ($100{\mu}M$), McN-A-343 ($100{\mu}M$), ACh (5.32 mM), Bay-K-8644 ($10{\mu}M$) and high $K^+$ (56 mM) respectively. How-ever, it did not affect CA secretion evoked by cyclopiazonic acid ($10{\mu}M$). Hypoxia itself also did fail to produce any influence on spontaneous secretory response of CA. These experimental results suggest that hypoxia depresses CA release evoked by both cholinergic stimulation and membrane-depolarization from the isolated rat adrenal medulla, and that this inhibitory activity may be due to the result of the direct inhibition of $Ca^{++}$ influx into the chromaffin cells without any effect on the calcium mobilization from the intracellular store.

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A study of teenager's perceptions of health behavior and health status (청소년들의 건강상태와 건강행위 인지에 관한 연구)

  • 조원정;김모임
    • Korean Journal of Health Education and Promotion
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    • v.4 no.2
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    • pp.32-45
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    • 1987
  • This research attempted to identify basic data related to the nursing of teenagers that would aid in the establishment of nursing care that would meet their health needs, and further to identify which health related activities, are carried out by teenagers, so that appropriate nursing service and health care can be planned for them. The subjects of the study were students at one seoul boys high school and one seoul girls high school. Data was collected between December 16 and. December 19, 1986. The tool used in the study was a questionnaire about the health needs and concerns of teenagers developed at John's Hopkins University and translated and standardized for Korean students. The date was coded fer analysis using' the SPSS program and percentages, mean scores' with standard deviations, Chi square test, and ANOVA, were used for analysis. The following results were obtained : 1. The health status of teenagers : Looking at the health status of teenagers, it can be seen from this study that over half of the teenagers questioned replied that they do not get enough sleep, further that even though they are feeling sick they go to school. However, when asked what they thought of their health, the majority replied that they were healthy, and although they thought about their bea1th was not a concern when they were planning other activities. With regard to health status, there was a significant difference between male and female students concerning whether they were handicapped with regard to sleep, their opinion about their own health, and the amount of time lost from school for illness over the past month, whether in comparison with those of the same age they had more sickeness of not, and whether they had to think about their health when planning other activities. There was also a significant difference according to the age of the students as to whether they worried more about being sick than other members of their age group. 2. Health Realted Activeties of Teenagers : Most of the students in the study reported that they did not get regular physical examinations of health check ups, nor did they get legular examinations when they were sick. Few students reported that they smoked. Most of the students reported taking part in activities that promoted health but about half also reported that they were involved in activities that they knew were detrimental to their health. Further on statistical analysis, there was a significant difference between male and female students regarding health related activities and problems of teenagers and whether they were examined by a medical person when they were sick. 3. The degree of interest and responsibility of teenagers for their own Health: In the section on responsibility for health, the teenagers replies were highest, 4. 5, for the statements, "My health is dependent how much I pay attention to it" and "My health is responsibility" and lowest, 3. 9, for the statement "I am healthy because I have cared for my health so far." With regard to interest in their own health, the majority of the teenagers in the study were more concerned about their studies, high score of 4. 4, than in matters directly related to health. The use of drugs, birth control and masturbation were low on the interest scale. The more involvement in health related activities, the higher the score was for responsibility and this difference was significant, but this did not apply to interest in health. Similarly there was also a significant difference regarding participation in activities known to be detrimental to health and responsiblity for health, but not for interest in health.

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Effect of Complex Extracts of Mushroom and Sharp Toothed Eel on the Skin Conditions with Atopic Dermatitis and Acne Symptoms (갯장어 및 버섯 혼합추출물의 아토피 및 여드름 피부개선 효과)

  • Cha, Wol-Suk;Yoo, Ji-Hyun;Min, Myung-Ja;Nam, Hyung-Gun;Kim, Yun-Soo;Shin, Hyun-Jae;Kim, Jong-Soo;Choi, On-You;Kim, Ran;Choi, Du-Bok
    • KSBB Journal
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    • v.25 no.4
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    • pp.387-394
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    • 2010
  • This study was conducted to investigate effect of complex extract of various mushrooms and sharp toothed eel on the skin conditions with atopic dermatitis and acne symptoms. The total phenol concentration was increased in order of hot water> ethanol> ethyl acetate> petroleum ether> chloroform extract. Especially, when the hot water extract was used, it was about 2-3 fold higher than that of ethyl acetate, petroleumether, and chloroform extract. When the complex extract concentration was increased from 1.0 to 50 mg/L, the DPPH scavenging rate increased from 10.1 to 81.4%. The reduction power was sharply increased from 0.05 to 0.27 (700 nm) when the complex extract concentration was increased from 25 to 75 mg/L. However, above 100 mg/L, it was not decreased. In the case of SOD-like activity, it was 45.7% at 100 mg/L. Total numbers of patients with atopic dermatitis were 15 and 5 patients with severe acne symptoms. According to photos taken before and after the treatment and questionnaire results, considerable improvements in skin conditions are observed in the patients with atopic dermatitis and acne. For atopic patients, erythema and edema have been improved but the degree of effect was dependent on the individual's constitution. Concerning acne, the effect of coating of the extracts was prominent for first week and the degree decreased with time till 4 weeks. The complex extracts wereefficient in soothing rash and maturation. Side effects such as a scar were not detected during the application and treatment.

Induction of Apoptosis and Antitumor Activity by Stichoposide D through the Generation of Ceramide in Human Leukemia Cells (Stichoposide D의 백혈병 세포주에서 세라마이드 생성을 통한 세포 사멸 유도 및 항암 작용)

  • Park, Eun-Seon;Yun, Seung-Hoon;Shin, Sung-Won;Kwak, Jong-Young;Park, Joo-In
    • Journal of Life Science
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    • v.22 no.6
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    • pp.760-771
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    • 2012
  • Marine triterpene glycosides are physiologically active natural compounds isolated from sea cucumbers(holothurians). It was demonstrated that they have a wide range of biological activities, including antifungal, cytotoxic, and antitumor effects. A previous study showed that stichoposide C (STC) isolated from Thelenota anax induces apoptosis through generation of ceramide by activation of acid sphingomyelinase (SMase) and neutral SMase in human leukemia cells. In this study, we investigated whether STD, a structural analog of STC, can induce apoptosis and examined the molecular mechanisms for its activity. It was found that STC and STD induce apoptosis in a dose- and time-dependent manner and lead to the activation of caspase-8, mitochondrial damage, activation of caspase-9, and activation of caspase-3 in K562 and HL-60 cells. STC activates acid SMase and neutral SMase, which results in the generation of ceramide. Specific inhibition of acid SMase or neutral SMase partially blocked STC-induced apoptosis, but not STD-induced apoptosis. In contrast, STD generates ceramide through the activation of ceramide synthase. Specific inhibition of ceramide synthase partially blocked STD-induced apoptosis, but not STC-induced apoptosis. Moreover, STC and STD markedly reduced tumor growth of HL-60 xenograft tumors and increased ceramide generation in vivo. These results indicate that STC and STD can induce apoptosis and have antitumor activity through the different molecular mechanisms, because they have a different sugar residue attached to aglycones. Thus, these results suggest that their actions are affected by a sugar residue attached to aglycones and they can be used as anticancer agents in the treatment of leukemia.

Improved Production Efficiencies of Various Adeno-Associated Virus (AAV) Serotypes and a Novel Universal AAV Titration Method (다양한 adeno-associated virus (AAV) 혈청형의 효율성 높은 생산법과 새로운 공통적 정량법 개발)

  • Cho, Young-Hwa;Choi, Ye-Jin;Yun, Jung-Hee;Kim, Nam-Hee;Choi, Mi-Ra;Choi, Young-Kook;Kim, Kyung-Hee;Lee, Young-Ill;Lee, Beom-Jun;Park, Kee-Rang
    • Journal of Life Science
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    • v.22 no.6
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    • pp.703-712
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    • 2012
  • Adeno-associated virus (AAV) has been considered to be a very safe and efficient gene delivery system. However, the major obstacles to therapeutic usage of AAV have been to achieve highly efficient and reproducible production processes, and also to develop a reliable quantifying method of various serotypes with a simple protocol. We compared the efficiency of the conventional production protocol of AAV2 and adenovirus (Ad) co-infection to that of a new method containing AAV2 infection followed by pHelper transfection. We tested HEK293 and 293T, and further examined the time-dependent changes of AAV2 production. The new method of AAV2 and pHelper DNA gave about ten times higher production efficiency than that of the conventional protocol. The highest production efficiency in 293T was achieved as $1.61{\times}10^5$ virus genomes (v.g.)/cell by the new method of 10 MOI of AAV2 infection and 5 days post-infection. This protocol of the highest efficiency was then applied to produce various AAV serotypes and showed the efficiencies higher than $10^5$ v.g./cell. Next, we designed the universal PCR primers of highly conserved regions for various AAV serotypes to develop a simple and reliable titration method. The universal primers could amplify all the tested AAV serotypes with similar sensitivities by ten molecular copies. Therefore, this pair of universal primers can be further utilized to detect AAV contaminants in therapeutic adenoviral vectors.

Toll-like Receptor 4-mediated Apoptotic Cell Death in Primary Isolated Human Cervical Cancers (부인과질환 특이적 종양의 TLR4 매개성 apoptosis 유발에 관한 연구)

  • Won, Jinyoung;Hong, Yunkyung;Park, Sookyoung;Kim, Joo-Heon;Hong, Yonggeun
    • Journal of Life Science
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    • v.28 no.6
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    • pp.718-725
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    • 2018
  • Toll-like receptor 4 (TLR4) has been implicated in cell proliferation and apoptosis in several types of cancer. In this study, the impact of TLR4 activation on apoptotic cell death in gynecologic cancers induced by lipopolysaccharide (LPS) was investigated. Cervical cancer cell lines were produced from isolated surgical specimens supplied by Paik Hospital. The primary cultures of normal myometrium and gynecologic cancers, including cervical, endometrial, and ovarian cancers, were used to examine the differences in morphological characteristics between normal and cancerous cells. A reverse transcription polymerase chain reaction analysis was used to determine the relative expression levels of TLR4 gene involved in apoptosis-associated signaling in cervical cancer cells. The cancer cell colonies showed a tendency to reach high levels of confluency compared with normal cells. In addition, an enhanced growth rate and loss of contact inhibition were observed in gynecologic cancer cells compared with normal cells (doubling times of 16.6 hr vs. 26 hr, respectively). The expression level of ITGA5, an alpha-5 integrin marker, was upregulated in normal myometrial cells, but this tendency was not exhibited in cervical cancer cells. Furthermore, p53 tumor suppressor gene expression was upregulated, whereas TLR4 and caspase-3 gene expressions were downregulated in cervical cancer cells. Notably, the expression levels of TLR4 and caspase-3 were increased significantly in LPS-treated cancer cells compared with those in non-LPS-treated cells. These results suggest that the TLR4-mediated caspase-dependent apoptotic signaling pathway could be suggested as a therapeutic target for the treatment of gynecologic cancers, including cervical cancers.

Ovarian and Endometrial $^{18}F$-FDG Uptake During the Menstrual Cycle in Normal Premenopausal Patients: Evaluation by PET/CT (월경주기에 따른 $^{18}F$-FDG PET/CT의 자궁 내 섭취에 관한 연구)

  • Bahn, Young-Kag;Park, Hoon-Hee;NamKoong, Hyuk;Kim, Sang-Kyoo;Lim, Han-Sang;Lee, Chang-Ho
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.3
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    • pp.43-47
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    • 2009
  • Purpose: The menstrual cycle of normal premenopausal patients was divide into menstrual flow phase, proliferative phase, ovulatory phase, secretory phase. The aim of this study was to ovarian and endometrial $^{18}F$-FDG uptake during the menstrual cycle in normal premenopausal patients. Materials and Methods: We identified 200 incidental $^{18}F$-FDG uptake in the ovary. The patient fasted at least 6 hours before receiving an intravenous injection of 370-592 MBq (10-16mCi) of $^{18}F$-FDG. Scanning from the base of the skull though the mid thigh was performed using the Discovery Ste PET/CT system (GE Healthcare, Milwaukee, WI, USA). Ovarian and endometrial $^{18}F$-FDG uptake (expressed as standardized uptake value) was measured on PET/CT image. Results: Two peaks of increased endometrial $^{18}F$-FDG uptake were identified during the menstrual cycle. The $SUV_{avg}$ and $SUV_{max}$ was $2.89{\pm}1.04$ and $3.17{\pm}1.59$ in menstruating patients, $2.4{\pm}0.88$ and $2.98{\pm}1.14$ in proliferative phase patients, $3.59{\pm}1.76$ and $3.17{\pm}1.67$ in ovulatory phase patients, $2.58{\pm}1.39$ and $3.1{\pm}1.8$ in secretory phase patients. Conclusions: Increased ovarian and endometrial $^{18}F$-FDG uptake could be found the time of menstrual flow and ovulatory phase of menstrual cycle. Increased uptake in endometrial adjacent to a cervical tumor does not necessarily reflect endometrial tumor invasion. Since increased uptake was dependent on the menstrual cycle, it can be avoided by scheduling PET/CT just after menstruation. Non-menstrual-related endometrial uptake may be instrumental in establishing a diagnosis in a premenopaual patient.

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