• Title/Summary/Keyword: Germinal center

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Ultrastructure of the Follicular Oocyte Surface in Rana dybowskii

  • Ju, Jung-Won;Im, Wook-Bin;Kwon, Hyuk Bang;Choi, Hueng-Sik
    • Animal cells and systems
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    • v.5 no.1
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    • pp.45-50
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    • 2001
  • Rana ovarian follicles consist of oocyte, vitelline envelope, granulosa cells, and theca/epithelial layer. Using scanning electron microscopy, the surface structure of each follicular component was investigated. Changes in oocyte surface during oocyte maturation were also examined. Theca/epithelial layer was almost transparent and some blood vessels and granulosa cells were observed underneath in intact follicle. The number of granulosa cells was estimated to be 6700-7200 per oocyte. The granulosa cells partially overlapped each other and their microvilli penetrated the vitelline membrane via holes present in the vitelline envelope and seemed to be linked to oocyte microvilli. After removal of the vitelline envelope by microforcep, oocyte microvilli were observed on the surface of the devitellined oocyte. The oocyte microvilli formed partial clusters on the surface of white spot area which appears iust before germinal vesicle breakdown (GVBD), whereas they were evenly distributed in other areas. The microvilli became shorter and less dense with oocyte maturation. The lengths of oocyte microvilli in the immature and mature oocyte were 1.5 $\mu$m and 0.6 $\mu$m, respectively. The present study suggests a fundamental structural change occurring on the oocyte surface during maturation.

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Effects of Climatic Factors and Picking Time on Availability of Seeds of Chamaecyparis obtusa

  • Son, Seog-Gu;Kim, Chan-Soo;Hwang, Seok-In;Jeong, Jin-Heon;Choi, Wan-Yong
    • Journal of Korean Society of Forest Science
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    • v.97 no.2
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    • pp.135-139
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    • 2008
  • Seed production and germination could be influenced by some factors. The picking time and climate factors are regarded as the elements to obtain sound seeds. We have observed the seed productivity and germination of seeds from trees of Chamaecyparis obtusa selected in a clonal seed orchard. Depending on picking time, various shapes from liquid material, something jellied to the fully matured one were observed. Germination aspects varied throughout the test days. After 20days of seeding in a glass petri-dish, germinal apparatuses appeared from the all seeds which had been picked from after at the end of August. The highest germination rate of about 30% was observed from the seeds picked from $20^{th}$ of September and $10^{th}$ of October. Seed production was about two times higher in 2005 than in 2006 and the average germination rate was also higher in 2005. We have also analyzed the effects of climatic factors about two consecutive years on seed productivity. Among the climatic factors, monthly sum of temperature and of precipitation were the main factors for maturation of Chamaecyparis obtusa seeds.

The treatment of Non-obstructive Azoospermia (비폐쇄성 무정자증의 치료)

  • Seo, Ju-Tae;Park, Yong-Seog;Kim, Jong-Hyun;Lee, You-Sik;Jun, Jin-Hyun;Lee, Ho-Joon;Son, Il-Pyo;Kang, Inn-Soo;Jun, Jong-Young
    • Clinical and Experimental Reproductive Medicine
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    • v.24 no.1
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    • pp.95-99
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    • 1997
  • Irreparable obstructive azoospermic patients can be treated successfully with microsurgical epididymal sperm aspiration(MESA) or testicular sperm extraction (TESE) by intracytoplasmic sperm injection(ICSI). Obstructive azoospermic patients generally have normal spermatogenesis. The aim of this study was to see if any spermatozoa could be retrieved from non-obstructive azoospermia and to assess the efficacy of ICSI with TESE in germinal failure. 42 non-obstructive azoospermic patients revealed no spermatozoa at all in their ejaculates, even after centrifuge. The histology of 42 patients revealed 15 Sertoli cell only Syndrome, 4 maturation arrest and 23 severe hypospermatogenesis. All patients underwent extensive multiple testicular biopsy for sperm retrieval. These patients were scheduled for ICSI using testicular spermatozoa. In 25 out of 42 non-obstructive azoospermic patients, spermatozoa were recovered from multiple testicular biopsy specimen and 11 ongoing pregnancies were achieved. There are usually some tiny foci of spermatogenesis which allow TESE with ICSI in non-obstructive azoospermia. Also these patients may have sufficient sperm in the testes for ICSI, despite extremely high FSH level and small testes.

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Activation-induced Cytidine Deaminase in B Cell Immunity and Cancers

  • Park, Seok-Rae
    • IMMUNE NETWORK
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    • v.12 no.6
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    • pp.230-239
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    • 2012
  • Activation-induced cytidine deaminase (AID) is an enzyme that is predominantly expressed in germinal center B cells and plays a pivotal role in immunoglobulin class switch recombination and somatic hypermutation for antibody (Ab) maturation. These two genetic processes endow Abs with protective functions against a multitude of antigens (pathogens) during humoral immune responses. In B cells, AID expression is regulated at the level of either transcriptional activation on AID gene loci or post-transcriptional suppression of AID mRNA. Furthermore, AID stabilization and targeting are determined by post-translational modifications and interactions with other cellular/nuclear factors. On the other hand, aberrant expression of AID causes B cell leukemias and lymphomas, including Burkitt's lymphoma caused by c-myc/IgH translocation. AID is also ectopically expressed in T cells and non-immune cells, and triggers point mutations in relevant DNA loci, resulting in tumorigenesis. Here, I review the recent literatures on the function of AID, regulation of AID expression, stability and targeting in B cells, and AID-related tumor formation.

Ultrastructural Localization of Mercury in Spleen of the Mouse (마우스 비장내 수은의 미세구조적 위치)

  • Cho, Hyun-Wook;Kim, Myung-Hoon;Yee, Sung-Tae
    • Applied Microscopy
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    • v.28 no.4
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    • pp.551-561
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    • 1998
  • The autometallographic method was used to demonstrate the localization of mercury deposits in spleen of mouse. The mercury deposits were identified with the light and electron mocroscope. Mice were treated with methylmercuric chloride in the drinking water (demineralized water) for 40 days. Control and mercury treated groups showed no significant differences in mean body weight and spleen weight per one mouse. Mercury grains were appeared in the germinal center of white pulp consist of a preponderancing lymphocytes, not in red pulp and capsule. At the ultrastructural level, mercury deposits were restricted to lysosomes of macrophage and lymphocyte. Specially, volume in lysosomes of the macrophage was increased. These results suggest that mercury localization in lysosomes is associated with the change of immune activity.

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Perspectives : Understanding the Pathophysiology of Intraventricular Hemorrhage in Preterm Infants and Considering of the Future Direction for Treatment

  • Young Soo Park
    • Journal of Korean Neurosurgical Society
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    • v.66 no.3
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    • pp.298-307
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    • 2023
  • Remarkable advances in neonatal care have significantly improved the survival of extremely low birth weight infants in recent years. However, intraventricular hemorrhage (IVH) continues to be a major complication in preterm infants, leading to a high incidence of cerebral palsy and cognitive impairment. IVH is primarily caused by disruption of the fragile vascular network of the subependymal germinal matrix, and subsequent ventricular dilatation adversely affects the developing infant brain. Based on recent research, periventricular white matter injury is caused not only by ischemia and morphological distortion due to ventricular dilatation but also by free iron and inflammatory cytokines derived from hematoma and its lysates. The current guidelines for the treatment of posthemorrhagic hydrocephalus (PHH) in preterm infants do not provide strong recommendations, but initiating treatment intervention based on ultrasound measurement values before the appearance of clinical symptoms of PHH has been proposed. Moreover, in the past decade, therapeutic interventions that actively remove hematomas and lysates have been introduced. The era is moving beyond cerebrospinal fluid shunt toward therapeutic goals aimed at improving neurodevelopmental outcomes.

Quantitative Analysis of Coumarins from Angelica gigas Using $^1H$-NMR

  • Yoo, Jong-Su;Ahn, Eun-Mi;Song, Myoung-Chong;Bang, Myun-Ho;Kim, Dong-Hyun;Han, Min-Woo;Kwak, Ho-Young;Lee, Dae-Young;Lyu, Ha-Na;Baek, Nam-In
    • Food Science and Biotechnology
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    • v.17 no.3
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    • pp.573-577
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    • 2008
  • $^1H$-Nuclear magnetic resonance (NMR) spectrometry was applied to the quantitative analysis of coumarins in the roots of Angelica gigas without any chromatographic purification. The experiment was performed by the analysis of each singlet germinal methyl, which was well separated in the range of 1.0-2.0 ppm in the $^1H$-NMR spectrum. The quantity of the compounds was calculated by the ratio of the intensity of each compound to the known amount of internal standard (dimethyl terephthalate). These results were compared with the conventional gas chromatography (GC) method. The contents of decursin and decursinol angelate in A. gigas were determined $1.98{\pm}0.07$, $1.13{\pm}0.08%$ in quantitative $^1H$-NMR method and $2.06{\pm}0.24$, $1.17{\pm}0.24%$ in GC method, respectively. The advantages of quantitative $^1H$-NMR analysis are that can be analyzed to identify and quantify, and no reference compounds required for calibration curves. Besides, it allows rapid and simple quantification for coumarins with an analysis time for only 10 min without any preprocessing.

Expression of Ids in Preimplantation Mouse Embryos (착상 전 생쥐배아에서 Id 유전자의 발현)

  • Hong, Seok-Ho;Nah, Hee-Young;Lee, Young-Jin;Lee, Ji-Won;Son, Young-Soo;Chae, Hee-Dong;Kim, Sung-Hoon;Kang, Byung-Moon;Kim, Chung-Hoon
    • Clinical and Experimental Reproductive Medicine
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    • v.31 no.4
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    • pp.201-207
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    • 2004
  • Objective: The Id family of helix-loop-helix proteins are thought to affect the balance between cell growth and differentiation by negatively regulating the function of basic-helix-loop-helix (bHLH) transcriptional factors. The aim of this study was to investigate the expression pattern of Ids (Id-1, -2, -3, and -4) in preimplantation mouse embryos at mRNA and protein levels. Methods: Oocytes and preimplantation embryos were collected from reproductive organs of female ICR mice following superovulation. RT-PCR was performed to investigate the mRNA expression patterns of Id genes and their protein were localized by immunofluorescence analysis. Results: Id-1 and Id-3 mRNAs were strongly expressed at the germinal vesicle (GV) oocyte and the blastocyst stages. Id-2 mRNA was expressed throughout preimplantation embryo development, but Id-4 was not expressed. Immunofluorescence showed that Id-1 and Id-2 were predominantly localized in cytoplasmic region, but the immunofluorescence signal of Id-3 was weak throughout preimplantation embryo development. Conclusion: These data show for the first time that Ids are expressed in preimplantation mouse embryos and suggest that Ids may play an important role in early preimplantation embryo development and uterine physiological changes.

In Vitro Growth of Preantral Follicle and Maturation of Intrafollicular Oocyte from Aged Mice

  • Yoon, Jung-Ah;Choi, Jung-Kyu
    • Journal of Animal Reproduction and Biotechnology
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    • v.34 no.1
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    • pp.35-39
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    • 2019
  • This study aimed to recover the ovarian function through in vitro culture of preantral follicles from aged mice. First, we isolated the preantral follicles from ovaries of sixty-seven-week old B6D2F1 mice with decreased fecundity to know how many follicles were present in them, which was 6 preantral follicles including 2 primary, 2 early secondary and late secondary follicles from 8 aged mice. It was confirmed that a few follicles (~2) were present in aged mice through histological analysis compared to adult mice as control. The 9 days of in vitro culture of preantal follicles showed in vitro growth and induced maturation after treatment with hCG (2.5 IU/mL) and EGF (5 ng/mL). Cumulus cells in the cumulus-oocyte complexes (COCs) were removed using hyaluronidase and oocytes at the germinal vesicle (GV) and GV breakdown (GVBD) were obtained from preantral follicle culture of aged mice in vitro. In conclusion, these observations demonstrated that there still were a few preantral follicles in the ovaries of 67 week-old mice, which we were able to culture in vitro and oocytes were obtained from them. This study proposed an in vitro culture system using preantral follicle as a therapeutic strategy for fertility preservation in humans for assisted reproductive medicine.

Kimura's Disease of the Distal Arm - A Case Report - (상완 원위부에 발생한 기무라씨 병 - 증례 보고 -)

  • Yoon, Jong-Pil;Jo, Ki-Hyun;Min, Hak-Jin;Yoon, Ui-Seoung;Seo, Jae-Seong;Kim, Jin-Soo;Baak, Cheol-Hee
    • Clinics in Shoulder and Elbow
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    • v.11 no.2
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    • pp.196-200
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    • 2008
  • Kimura's Disease is a very rare, chronic inflammatory disorder with an unknown etiology, and this illness is primarily seen in young Asian males. The typical clinical features consist of painless subcutaneous masses in the head or neck region, and especially in the salivary gland and submandibular region. It is often accompanied with a regional lymphadenopathy, peripheral blood eosinophilia and elevated serum IgE levels. Histologically, it is characterized by prominent germinal centers in the involved lymph nodes, together with eosinophilic infiltration in these lymph nodes. The treatment modalities for this disease are steroid therapy, radiation therapy and surgical excision. Its clinical course is of a benign nature. We report here on a case of a 28 year old man who had a soft tissue mass in his left arm. We excised this mass and the microscopy confirmed that he suffered from Kimura's disease on microscopic examination in his left distal arm.