• Development and Reproduction
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• v.18 no.4
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• pp.321-327
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• 2014

Ultrastructural studies of oocyte degeneration in the oocyte, and the functions of follicle cells during oocyte degeneration are described to clarify the reproductive mechanism on oocyte degeneration of Mactra chinensis using cytological methods. Commonly, the follicle cells are attached to the oocyte. Follicle cells play an important role in oocyte degeneration. In particular, the functions of follicle cells during oocyte degeneration are associated with phagocytosis and the intracellular digestion of products. In this study, morphologically similar degenerated phagosomes (various lysosomes), which were observed in the degenerated oocytes, appeared in the follicle cells. After the spawning of the oocytes, the follicle cells were involved in oocyte degeneration through phagocytosis by phagolysosomes. Therefore, it can be assumed that follicle cells reabsorb phagosomes from degenerated oocytes. In this study, the presence of lipid granules, which occurred from degenerating yolk granules, gradually increased in degenerating oocytes. The function of follicle cells can accumulate reserves of lipid granules and glycogen in the cytoplasm, which can be employed by the vitellogenic oocyte. Based on observations of follicle cells attached to degenerating oocytes after spawning, the follicle cells of this species are involved in the lysosomal induction of oocyte degeneration for the reabsorption of phagosomes (phagolysosomes) in the cytoplasm for nutrient storage, as seen in other bivalves.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.8
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• pp.1173-1177
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• 2011

In this study wool follicle characteristics of Iranian sheep breeds were investigated. A total of 242 male and female sheep of different age from 5 breeds were studied. Samples of skin were taken from the right midside to determine follicle characteristics. Overall averages for males and females were $3.7{\pm}0.1$ and $3.5{\pm}0.1$ for S/P ratio; $3.2{\pm}0.1$ and $3.6{\pm}0.1$ for primary follicle density; $12.1{\pm}0.7$ and $13.8{\pm}0.4$ for secondary follicle density; $15.3{\pm}0.7$ and $17.4{\pm}0.4$ for total primary plus secondary follicle density; $2.3{\pm}0.2$ and $3.5{\pm}0.3$ for percentage of inactive secondary follicles. Significant differences were found in some follicle characteristics between sheep breeds. Results of this study showed that sheep breeds raised in different parts of Iran characterized by a low S/P ratio and follicle density could be classed as carpet wool breeds.

• Journal of Veterinary Clinics
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• v.27 no.1
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• pp.46-49
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• 2010

In this study, we investigated the number of follicles, oocyte recovery rate and oocyte competence after in vitro maturation according to the size of follicle. And equine oocyte competence after in vitro maturation was investigated in terms of the diameter of follicle with criteria of maturation: nuclear stage after Hoechst staining. The average number of follicles per ovary with middle size (11-20 mm, 2.68) was higher than those of small (5-10 mm, 0.74) and large size follicle (> 21 mm, 1.63), therefore medium follicle (53.1%) had higher proportion than other size of follicles. The average numbers of follicle per ovary was 5.05. The rate of oocyte recovery in small (54.5%) and middle follicle (50%) was higher than that in large follicle (40.9%). After culture for 48 h in Medium 199, 50%, 45.5%, and 44.4% of oocytes from the follicles with diameters of 5-10, 11-20, > 21 mm, respectively reached the metaphase II stage. This is the first report showing number of follicle, oocyte recovery rate according to follicular size, and in vitro oocyte maturation in Jeju mare in Korea. To fulfill in vitro equine embryo production, further studies such as the seasonal effect, in vitro fertilization etc is need.

• Applied Microscopy
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• v.27 no.3
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• pp.321-332
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• 1997

The dermal papilla is known to playa major role in influencing the form and dynamics of the hair follicle, which probably involves regulatory substances crossing the basal lamina. But little is known about the junctions between the dermal papilla and the surrounding epithelial cells of the hair bulb, or between the connective tissue and the epithelial cells on the outside of the hair follicle. This study was performed to identify the ultrastructural differences between dermoepidermal junction of the skin and connective tissue-epithelial junctions on the outside of the hair follicle and around the dermal papilla of normal anagen hair follicles in the human fetal scalp skin. Electron microscopic findings of dermoepidermal junction in scalp skin showed that basal lamina was very irregular and undulated, and it contained many attachment plaques of hemidesmosomes with sub-basal dense plates, tonofilaments, and anchoring filaments. Also invaginations of plasma membrane of basal keratinocytes were seen. There were clear differences both on the outside of the follicle and around the dermal papilla as compared with similar junction in the skin. In particular, neither hemidesmosomes nor tonofilaments, as seen in dermoepidermal junction, were observed in the dermal papilla. Also attachment plaque, sub-basal dense plate and anchoring filaments were not observed at the junction on the outside of the follicle and the dermal papilla. There were some differences between connective tissue-epithelial junctions on the outside of the hair follicle and around the dermal papilla, ie, smoothness of basal lamina and orthogonal arrangement of collagen fibers were seen in the outside of hair follicle, but not in the dermal papilla. These results indicate that the mechanical connection between the hair follicle and the connective tissue component is much weaker than that between the corresponding components in skin, and it reflects the dynamic processes during the anagen phase of the hair follicle compared to the relatively permanent state of the epidermis.

• Journal of Embryo Transfer
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• v.14 no.3
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• pp.203-210
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• 1999

In this stuyd, the effect of the dominant follicle aspiration for the superovulatory response in HanWoo was investigated. The criterion for the presence or absence of a dominant follicle based on their morphological examination. The dominant follicle was aspirated 48hr before the onset of superovulation treatment by 6.5MHz convex probe connected with a carrier and superovulation induced by FSH (Super-Ov Tyrer, Texas, U.S.A) adminstered twic a day s.c. over 4 day in a decreasing regimen. From 13 HanWoo scanned daily to determine the presence and growth of the dominant follicle, its an average diameter of 15.4mm was measured and an average diameter of corpora lutea was 18.7mm on day of follicular aspiration. In the experiment, a follicular remove by ultrasound-guided aspiration, the ovarian response was significantly enhanced when animals were superovulated in the aspiation of a dominant follicle compare with animals superovulated non-aspiration of a dominat follicle. In the aspiration of a dominant follicle donors yieleded more corpora lutea(14.4$\pm$4.7 vs 8.6$\pm$3.4) and transferable embryos(8.9$\pm$4.2 vs 5.4$\pm$2.7) than control. In cows in which the dominant follicle had been aspirated under sonographical control 2 days before superovuation, the number of corpus lutea and transferable embryos were significantly enhanced compared with animals superovulated in the presence of a dominant follicle (14.4$\pm$4.7 vs 6.9$\pm$2.7, ; 8.9$\pm$4.2 vs 3.3$\pm$1.6). After 7 days of artificial insemination, the embryos at 7 days were cllected by uterine flushing after dominant follicle insemination, the embryos at 7 days were collected by uterine flushing after dominant follicle aspiration and superovulation treatment, and evaluated their quality by morphological criteria. Sixteen embryos with excellent and good grade were transferred into 8 recipient cows. Six pregnancies were identified at 60 and 120 days of gestation by rectal palpations. In conclusion, the present study showed that 1) the presence or absence of a dominant follicle signficicnatly affects superovulatory responses, and 2) ultrasound-guided follicular aspiration of the dominant follicle and superovuation treatment provides an accurate and procedure to increase ovarian responses in HanWoo.

• Clinical and Experimental Reproductive Medicine
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• v.39 no.3
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• pp.95-106
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• 2012

It has been revealed that multiple cohorts of tertiary follicles develop during some animal estrous cycle and the human menstrual cycle. To reach developmental competence, oocytes need the support of somatic cells. During embryogenesis, the primordial germ cells appear, travel to the gonadal rudiments, and form follicles. The female germ cells develop within the somatic cells of the ovary, granulosa cells, and theca cells. How the oocyte and follicle cells support each other has been seriously studied. The latest technologies in genes and proteins and genetic engineering have allowed us to collect a great deal of information about folliculogenesis. For example, a few web pages (http://www.ncbi.nlm. nih.gov; http://mrg.genetics.washington.edu) provide access to databases of genomes, sequences of transcriptomes, and various tools for analyzing and discovering genes important in ovarian development. Formation of the antrum (tertiary follicle) is the final phase of folliculogenesis and the transition from intraovarian to extraovian regulation. This final step coordinates with the hypothalamic-pituitary-ovarian axis. On the other hand, currently, follicle physiology is under intense investigation, as little is known about how to overcome women's ovarian problems or how to develop competent oocytes from in vitro follicle culture or transplantation. In this review, some of the known roles of hormones and some of the genes involved in tertiary follicle growth and the general characteristics of tertiary follicles are summarized. In addition, in vitro culture of tertiary follicles is also discussed as a study model and an assisted reproductive technology model.

• The Korean Journal of Malacology
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• v.24 no.1
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• pp.33-40
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• 2008

Ultastructural studies of oocyte degeneration and follicle cells in female Spisula sachalinensis are described for clams collected from Jumunjin, Gangwondo, Korea. The follicle cells playan integral role in vitellogenesis and oocyte degeneration by assimilating products originating from the degenerated oocytes (thus allowed the transfer of yolk precursors needed for vitellogenesis). The functions of the follicle cells include phagocytosis and intracellular digestion of products originating from oocyte degeneration. During the period of oocyte degeneration, follicle cells of this species probably have lysosomal systems for the breakdown and reabsorption of various phagosomes(phagolysosomes) in the cytoplasm for nutrient storage; this process has been observed in other bivalves.

• Archives of Pharmacal Research
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• v.13 no.4
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• pp.379-381
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• 1990

The effect of calcium gluconate on estrogen (estradiol) serum level as well as follicle stimulating hormone level was studied. Our results revealed that oral administration of calcium gluconate (100 mg/kg body wight) to adult non-pregnant female rabbits caused a significant increase of serum levels of estradiol and follicle stimulating hormone. On the other hand, oral contraceptive (Norminest tablets) decreased significantly follicle stimulating hormone serum level, while combined administration of calcium gluconate and oral contraceptive caused significant increase of serum level of follicle stimulating hormone compared with control values. Also, concurrent administration of calcium gluconate and Norminest tablet increased significantly the rate of conception compared with group recieved Norminest tablets only. These results indicated that combined administration of calcium and oral contraceptives must be cautiously.

• Molecules and Cells
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• v.46 no.10
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• pp.573-578
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• 2023

The mammalian skin contains hair follicles, which are epidermal appendages that undergo periodic cycles and exhibit mini-organ features, such as discrete stem cell compartments and different cellular components. Wound-induced hair follicle neogenesis (WIHN) is the remarkable ability to regenerate hair follicles after large-scale wounding and occurs in several adult mammals. WIHN is comparable to embryonic hair follicle development in its processes. Researchers are beginning to identify the stem cells that, in response to wounding, develop into neogenic hair follicles, as well as to understand the functions of immune cells, mesenchymal cells, and several signaling pathways that are essential for this process. WIHN represents a promising therapeutic approach to the reprogramming of cellular states for promoting hair follicle regeneration and preventing scar formation. In the scope of this review, we investigate the contribution of several cell types and molecular mechanisms to WIHN.

• Clinical and Experimental Reproductive Medicine
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• v.12 no.1
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• pp.83-98
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• 1985

In order to study the mechanism of follicular atresia, the follicles of the porcine ovary were isolated according to the presence or absence of the corpus luteum and their size, and then classified to the normal? or atretic?follicle on the morphological observation such as the transparency, the vascularization of follicle, the nuclear phase of oocyte, and the homogeneity of the granulosa cell layer. The viability of granulosa cells was examined. The concentrations of progesterone ($P_4$), testosterone (T), and estradiol-17 beta ($E_2$) in each follicular fluid were estimated by the radioimmunoassay. The viability of granulosa cells in the atretic follicle was much lower than that of the normal one. The concentration of each steroid hormone increased as the follicular size was increased, was not different in quantity between the normal- and the atretic follicle of which diameter was below 3mm, and were much higher in the atretic follicle than those in the normal one of which diameter was above 7mm. The ratio of the concentration of E2 to T in the large atretic follicle valued higher than that in the normal one, but smaller in the small and medium atretic follicle than that in the normal one. The present study suggests that the mechanism of atresia of the large follicle may be different from that of the small and the medium follicle and that the amount of steroid hormones regarded as the one of the criteria for the atretic follicles.