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Follicle Growth (follicle + growth)
Selected AbstractsFolliculogenesis and Morphometry of Oocyte and Follicle Growth in the Feline OvaryREPRODUCTION IN DOMESTIC ANIMALS, Issue 2 2009K Reynaud Contents This study was designed to describe, both quantitatively (morphometry) and qualitatively (histological differentiation), follicle and oocyte growth in the feline ovary. The ovaries of 43 cats were collected and processed for histology. The diameters of 832 follicle/oocyte pairs were measured, with and without zona pellucida (ZP), and a special emphasis was placed on the study of early folliculogenesis. Primordial, primary, secondary, pre-antral and early antral follicles were measured at 44.3, 86.2, 126.0, 155.6 and 223.8 ,m in diameter respectively. A biphasic pattern of follicle and oocyte growth was observed. Before antrum formation, follicle (x) and oocyte (y) size were positively and linearly correlated (y = 0.500x + 20.01, r2 = 0.89). Antrum formation occurred when the follicle reached 160,200 ,m in diameter (when oocyte was at 102 ,m). After antrum formation, a decoupling was observed, a minimal increase in oocyte size contrasting with a significant follicle development (y = 0.001x + 114.39, r2 = 0.01). The pre-ovulatory follicle diameter was approximately 3500 ,m and the maximal oocyte diameter was 115 ,m. The ZP, absent in primordial and primary follicles, appeared at the secondary stage and reached almost 6 ,m at the pre-ovulatory stage. These results suggest that (i) in feline ovary, follicle and oocyte growth pattern is similar to that observed in other mammals; (ii) the antrum forms in 160,200 ,m follicles, which represents 5% of the pre-ovulatory diameter and (iii) the oocyte had achieved more than 90% of its maximal growth at the stage of antrum formation. [source] In vitro Follicle Growth: Achievements in Mammalian SpeciesREPRODUCTION IN DOMESTIC ANIMALS, Issue 1 2001R Cortvrindt The exact mechanisms regulating in vivo folliculogenesis in mammalians have only been partly unravelled. Some processes, such as the initiation of growth of primordial follicles are still poorly understood. This increases the difficulty to culture follicles in vitro as the primordial follicles will be the ultimate starting material for culture. There are important species differences in regulation and timing of maturation, which makes it difficult to transpose techniques. Only in the mouse model, live pups were born when primordial or early preantral follicles were cultured entirely in vitro. Although no systems are as yet permitting complete in vitro culture of early follicle stages in large animals or humans, parts of folliculogenesis have been successfully reproduced in vitro. This review summarizes achievements of the last years in follicle culturing starting off at several stages of development. Future applications of in vitro follicle culture include fertility preservation for humans, preservation of rare animal species and creation of oocyte banks for research. [source] Etiology of cicatricial alopecias: a basic science point of viewDERMATOLOGIC THERAPY, Issue 4 2008Kevin J. McElwee ABSTRACT: This article presents a short summary of our current knowledge of cicatricial alopecia disease pathogenesis and the hypothetical disease mechanisms that may be involved in scarring alopecia development. Several forms of scarring alopecia likely involve targeted cytotoxic action against hair follicle cells mediated by a folliculocentric inflammation. However, the specific nature of the inflammatory interference in hair follicle growth is open to question. A popular hypothesis of lymphocyte-mediated scarring alopecia development involves autoimmune targeting of hair follicle,specific self-antigens, although there is no direct evidence in support of such a view. Alternative hypotheses focus on defects in sebaceous gland function, destruction of hair follicle stem cells, and interference in the communication between hair follicle mesenchyme and epithelium. Many questions arise from these hypotheses, and addressing them with a systematic research approach may enable significant advances in understanding cicatricial alopecia etiology. [source] Interleukin-6 cytokine family member oncostatin M is a hair-follicle-expressed factor with hair growth inhibitory propertiesEXPERIMENTAL DERMATOLOGY, Issue 1 2008Mei Yu Abstract:, The activation of receptor complexes containing glycoprotein 130 (gp130) identifies the interleukin (IL)-6 cytokine family. We examined members of this family for their expression and activity in hair follicles. Quantitative polymerase chain reaction using mRNA derived from microdissected, anagen-stage human hair follicles and comparison to non-follicular skin epithelium revealed higher levels of IL-6 (15.5-fold) and oncostatin M (OSM, 3.4-fold) in hair follicles. In contrast, expression of all mRNAs coding for IL-6 cytokine family receptors was reduced. Immunohistology suggested expression of OSM, gp130, leukaemia inhibitory factor receptor (LIFr) and IL-11r in the hair follicle root sheaths and dermal papilla, while IL-11, IL-6r and OSMr were expressed in root sheaths alone. IL-6 was expressed in the dermal papilla while cardiotrophin-1 (CT-1) and LIF were not observed. OSM and to a lesser extent CT-1 exhibited a dose-dependent growth inhibition capacity on human hair follicles in vitro. OSM and CT-1 incubated with agarose beads and injected subcutaneously at 1 ,g per mouse into telogen skin of 65-day-old mice revealed no capacity to induce anagen hair growth. In contrast, injection of 65-day-old mice in which anagen had been induced by hair plucking revealed a moderate hair growth inhibitory capacity for OSM, but no significant effect for CT-1. The data identify OSM as a modulator of hair follicle growth and suggest other family members may also have some degree of hair growth inhibitory effect. In principle, increased expression of some IL-6 cytokine family members in cutaneous inflammation might contribute to the promotion of hair loss. [source] 6-O glucose linoleate supports in vitro human hair growth and lipid synthesisINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 2 2007P. Vingler Synopsis The hair follicle is a very active organ with a complex structure, which produces a hair fibre at a rate of 0.3 mm a day. Accordingly, the hair follicle is highly demanding in energy source, as the hair bulb matrix cells are endowed with one of the highest rates of proliferation in the human body. Moreover, recent data have shown the involvement of lipids in hair follicle function. As in vitro -grown hair follicle keeps producing a hair fibre that closely resembles the natural hair fibre, we decided to use this model to investigate the role of a new of glucose linoleate derivative (6-O-linoleyl- d -glucose: 6-O-GL) as a lipid precursor and energy provider. Our results demonstrated that 6-O-GL was (i) quite stable and surprisingly resistant to oxidative degradation, and (ii) readily taken up and metabolized by the hair follicle into various lipids, namely neutral lipids, ceramides and polar lipids. Moreover, it supported hair follicle growth and survival in a glucose- and linoleic-acid free medium. 6-O-GL thus appeared to be a bi-functional nutrient, ensuring both proper fibre quality and production by the hair follicle. Résumé Le follicule pileux est un organe très actif et d'une structure très complexe, qui produit la tige pilaire au rythme de 0.3 mm par jour. En conséquence, le follicule pileux est très demandeur en ressources énergétiques, les cellules de la matrice bulbaire ayant un des taux de prolifération les plus élevé de l'organisme. De plus des études récentes ont mis en évidence le rôle de lipides dans le fonctionnement du follicule pileux. Puisque le follicule pileux in vitro continue à produire une fibre de qualité identique à celle d'une fibre naturelle, nous avons décidé d'utiliser ce modèle pour étudier le rôle d'un nouveau linoléate de glucose (6-O-linoleyl- d -glucose: 6-O-GL) en tant que précurseur lipidique et source d'énergie. Nos résultats démontrent que le 6-O-GL est très stable et étonnamment résistant à l'auto oxydation, qu'il est capté et métabolisé par le follicule pileux en divers lipides, neutres, polaires et céramides. De plus, le 6-O-GL soutient la croissance et la survie du follicule dans un milieu dépourvu de glucose et d'acide linoléique. Le 6-O-GL apparaît donc comme un agent bi-fonctionnel, permettant au follicule pileux de maintenir in vitro la production de la tige pilaire. [source] Immunohistochemical localization of the bone morphogenetic protein receptors in the porcine ovaryJOURNAL OF ANATOMY, Issue 1 2004Ruth L. Quinn Abstract The bone morphogenetic protein (BMP) family is emerging as playing a crucial role in regulating normal follicle growth and determining ovulation rate. BMPs exert their effects via BMP receptors (BMPR-IA, -IB and -II). However, there is a paucity of information relating to the expression of the BMPRs within the ovary of large polyovular species such as the pig. Furthermore, there is a lack of information on the expression of BMPRs by fetal ovaries of any species. The purpose of this study was to investigate temporal and spatial expression of the BMPRs in the porcine ovary, at different developmental stages. Immunohistochemistry for BMPR-IA, BMPR-IB and BMPR-II was performed using sections from paraffin wax-embedded ovaries, obtained from fetal (n = 15), prepubertal (n = 3) and cycling postpubertal (n = 4) pigs. Results confirmed the presence of all three receptors in the fetal egg nests and in the granulosa cell layer of follicles ranging from primordial to late antral stages. Immunostaining was also observed in oocytes, theca layer, corpus luteum and ovarian surface epithelium. The expression of BMPRs by fetal ovaries may be related to follicle formation, whereas expression in pre- and post-pubertal animals indicates BMPs are involved in regulating porcine ovarian follicle growth. [source] Steady-state level of kit ligand mRNA in goat ovaries and the role of kit ligand in preantral follicle survival and growth in vitroMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 3 2010Juliana J.H. Celestino The aims of this study were to investigate steady-state level of Kit Ligand (KL) mRNA and its effects on in vitro survival and growth of caprine preantral follicles. RT-PCR was used to analyze caprine steady-state level of KL mRNA in primordial, primary, and secondary follicles, and in small (1,3,mm) and large (3,6,mm) antral follicles. Furthermore, ovarian fragments were cultured for 1 or 7 days in Minimal Essential Medium (MEM+) supplemented with KL (0, 1, 10, 50, 100, or 200,ng/ml). Noncultured (control) and cultured fragments were processed for histology and transmission electron microscopy (TEM). RT-PCR demonstrated an increase in steady-state level of KL mRNA during the transition from primary to secondary follicles. Small antral follicles had higher steady-state levels of KL mRNA in granulosa and theca cells than large follicles. After 7 days, only 50,ng/ml of KL had maintained the percentage of normal follicles similar to control. After 1 day, all KL concentrations reduced the percentage of primordial follicles and increased the percentage of growing follicles. KL at 10, 50, 100, or 200,ng/ml increased primary follicles, compared to MEM+ after 7 days. An increase in oocyte and follicular diameter was observed at 50,ng/ml of KL. TEM confirmed ultrastructural integrity of follicles after 7 days at 50,ng/ml of KL. In conclusion, the KL mRNAs were detected in all follicular categories. Furthermore, 50,ng/ml of KL maintained the integrity of caprine preantral follicle cultured for 7 days and stimulated primordial follicle activation and follicle growth. Mol. Reprod. Dev. 77: 231,240, 2010. © 2009 Wiley-Liss, Inc. [source] Effect of Suppression of FSH with a GnRH Antagonist (Acyline) Before and During Follicle Deviation in the MareREPRODUCTION IN DOMESTIC ANIMALS, Issue 3 2009CM Checura Contents A GnRH antagonist (Acyline) was used to study the role of FSH in early development of a follicular wave in 61 mares. In Experiment 1, a single dose of 3 mg per mare, compared with 0 and 1 mg, suppressed both the FSH and follicle responses to exogenous GnRH. In Experiment 2, high concentrations of FSH were induced by two successive ablations of all follicles , 6 mm on days 10 and 13 (day 0 = ovulation). A single treatment with Acyline resulted in significantly greater suppression of plasma concentrations of FSH than a single treatment with charcoal-extracted follicular fluid (source of inhibin) or oestradiol. Suppression of FSH was not significantly different between the group treated with Acyline alone and a group treated with a combination of Acyline, inhibin and oestradiol. In Experiment 3, all follicles were ablated on day 10 to induce an FSH surge and a new follicular wave. Acyline treatment on day 10 resulted in an immediate decrease in FSH, without a significant effect on day of emergence of a new wave or growth of follicles from 7 to 11 mm on days 11,13. Treatment on day 15, a day before expected follicle deviation and after the peak of the wave-stimulating FSH surge, resulted in an immediate decrease in FSH and cessation of follicle growth. Results indicated that growth of follicles for about 2 days after wave emergence was independent of FSH. In contrast, during the decline in the wave-stimulating FSH surge and before follicle deviation, growth of follicles was dependent on FSH. [source] Characteristics of Ovarian Follicle Development in Domestic AnimalsREPRODUCTION IN DOMESTIC ANIMALS, Issue 4 2003ACO Evans Contents In most domestic animals the later stages of follicle development occurs in a wave-like pattern during oestrous cycles (cattle, sheep, goats, horses and buffalo) or periods of reproductive activity (llamas and camels). A follicle wave is the organized development of a cohort of gonadotrophin-dependent follicles all of which initially increase in size, but most of which subsequently regress and die by atresia (subordinate follicles). The number of remaining (dominant) follicles is specific to the species and is indicative of litter size. Follicle waves develop during both luteal and follicular phases and it is the dominant follicle(s) of the last follicular wave that ovulates. However, there are cases where dominant follicles from the last two follicle waves can ovulate (sheep and goats). There are exceptions to the organized wave-like pattern of follicle growth where follicle development is apparently continuous (pigs and chickens). In these animals many follicles develop to intermediate diameters and at specific times follicles that are destined to ovulate are selected from this pool and continue growing to ovulation. Understanding the pattern of follicle development in different species is increasingly important for designing improved methods to manipulate reproduction in domestic animals. [source] Follicle Wave Growth in CattleREPRODUCTION IN DOMESTIC ANIMALS, Issue 4 2002M Mihm Contents Ovarian follicle growth in cattle culminates in the selection of a single dominant follicle which attains the ability for final maturation and ovulation once or twice during the luteal phase and at the end of the oestrous cycle, as well as during other reproductive states. This review will describe in detail the first follicle wave of the cycle leading to selection of the first wave dominant follicle, indicating the specific gonadotrophin dependencies of cohort and dominant follicles, and relating follicle fate to steroidogenesis. As a differential gonadotrophin response of growing antral follicles during the follies-stimulating hormone (FSH) decline may determine which follicle becomes selected, first wave follicles are also characterized in relation to intrafollicular growth factors, which may modify the gonadotrophin response, such as inhibins and members of the insulin-like growth factor (IGF) family. Subsequently, the follicular control of the transient FSH rise and decline so crucial to dominant follicle selection will be discussed. It is concluded that successful hormonal manipulation of follicle wave growth and dominant follicle selection will depend on our detailed understanding of the gonadotrophin requirements of differentiating wave follicles. [source] Evaluation of antral follicle growth in the macaque ovary during the menstrual cycle and controlled ovarian stimulation by high-resolution ultrasonographyAMERICAN JOURNAL OF PRIMATOLOGY, Issue 5 2009Cecily V. Bishop Abstract To date, ultrasonography of monkey ovaries is rare and typically of low resolution. The objectives of this study were to use state-of-the-art, high-resolution, transabdominal ultrasonography with real-time Doppler capabilities to: (1) determine whether one can reliably detect in real time the large dominant follicle, the corpus luteum (CL), and small (<2,mm) antral follicles on the ovaries of rhesus monkeys during the natural menstrual cycle; and (2) predict the follicular response of rhesus ovaries to controlled ovarian stimulation (COS) protocols. Rhesus monkeys were selected for transabdominal ultrasonography using a GE Voluson 730 Expert Doppler System at discrete stages of the menstrual cycle. Subsequently, serial ultrasound scanning was employed to observe growth of antral follicles and the CL. Finally, females were scanned to assess follicular growth during COS. The dominant structure and small antral follicles (<2,mm) were reliably visualized in real time. The follicle destined to ovulate could be identified by size differential by day 3 of the follicular phase. The number of small antral follicles present before onset of COS protocol correlated positively with the number of metaphase II-stage oocytes collected after treatment. The results of this study demonstrate that the population dynamics of antral follicle pools can be noninvasively evaluated in monkeys during natural and pharmacologic ovarian cycles. Am. J. Primatol. 71:384,392, 2009. © 2009 Wiley-Liss, Inc. [source] Characterization of the methylation status of five imprinted genes in sheep gametesANIMAL GENETICS, Issue 6 2009A. Colosimo Summary Genomic imprinting is a mammalian developmental process that uses epigenetic mechanisms to induce monoallelic and parental-specific expression of particular autosomal genes. A crucial epigenetic event consists of DNA methylation of CpG-islands, which become differentially methylated regions (DMRs) on the maternal and paternal alleles during oogenesis or spermatogenesis (germline DMRs). By contrast, somatic DMRs are acquired after fertilization. While there are several studies referring to methylation acquisition within germline DMRs in the mouse and human, a comparable methylation analysis of orthologous sequences is still lacking in sheep. To identify germline DMRs, this study analysed the methylation status of the available CpG-islands of five ovine imprinted genes (H19, IGF2R, DLK1, DIO3 and BEGAIN) in mature spermatozoa and in female gametes at different stages of their follicle growth, including in vitro matured oocytes. The 5,-end CpG-island of H19 showed a full methylation in spermatozoa and an absent methylation in growing and fully grown oocytes. The intron 2 CpG-island of IGF2R was unmethylated in male gametes, while it showed a high level of methylation in early stages of oogenesis. The promoter CpG-islands of DLK1 and DIO3 were found to be unmethylated both in spermatozoa and oocytes. Finally, the exon 9 CpG-island of BEGAIN was hypermethylated in mature male gametes, while it showed an almost complete methylation only in late stages of oocyte development. Our findings suggest that DNA methylation establishment during early stages of sheep oogenesis and subsequent in vitro maturation is gene-specific and that, of the five genes investigated, only the CpG-islands of H19 and IGF2R might represent ovine germline DMRs. [source] Chronic cystic ovarian disease in a Holstein cowAUSTRALIAN VETERINARY JOURNAL, Issue 1-2 2005AM PADULA Cystic ovarian follicles are commonly found during rectal examination of early postpartum dairy cows, usually presenting with anoestrus and occasionally nymphomania. Most cases self cure with time, or respond to exogenous hormonal treatment. This case report describes a refractory case in a Holstein cow in which a novel treatment approach was used. A gonadotrophin releasing hormone agonist implant was inserted for 180 d in an attempt to suppress pituitary gonadotrophin output, arrest abnormal ovarian follicle growth and prevent steroidogenesis. Frequent serial blood samples were collected before and after implant insertion to monitor changes in pulse release of luteinising hormone. Follow up ultrasound scans and blood samples were done to monitor ovarian structures; progesterone and oestradiol were collected at various times over the 180 d period. A normal, cycling herdmate was enrolled as a control. Prior to implant insertion, high frequency and low amplitude luteinising hormone pulses were detected in the cystic cow. Insertion was followed by a sustained surge in the release of luteinising hormone in both cows, but ovulation was not induced in the cystic cow. Plasma oestradiol levels remained consistently elevated and signs of oestrous behaviour were observed. Long term gonadotrophin releasing hormone agonist treatment failed to suppress either ovarian steroid production or cause regression of the cysts by 180 d. [source] Anti-Müllerian hormone (AMH) in female reproduction: is measurement of circulating AMH a useful tool?CLINICAL ENDOCRINOLOGY, Issue 6 2006A. La Marca Summary Anti-Müllerian hormone (AMH) is a dimeric glycoprotein, a member of the transforming growth factor (TGF) superfamily. It is produced exclusively in the gonads and is involved in the regulation of follicular growth and development. In the ovary AMH is produced by the granulosa cells of early developing follicles and seems to be able to inhibit the initiation of primordial follicle growth and FSH-induced follicle growth. As AMH is largely expressed throughout folliculogenesis, from the primary follicular stage towards the antral stage, serum levels of AMH may represent both the quantity and quality of the ovarian follicle pool. Compared to other ovarian tests, AMH seems to be the best marker reflecting the decline of reproductive age. AMH measurement could be useful in the prediction of the menopausal transition. It could also be used to predict poor ovarian response and possibly the prognosis of in vitro fertilization (IVF) cycles. AMH has been shown to be a good surrogate marker for polycystic ovary syndrome (PCOS). Finally, its use as a marker for granulosa cell tumours has been proposed. A clearer understanding of its role in ovarian physiology may help clinicians to find a role for AMH measurement in the field of reproductive medicine. [source] FSH and ovarian response: spontaneous recovery of pituitary,ovarian activity during the pill-free period vs. exogenous recombinant FSH during high-dose combined oral contraceptivesCLINICAL ENDOCRINOLOGY, Issue 4 2002A. M. Van Heusden Summary ojbective Compare spontaneous recovery of pituitary,ovarian activity during the pill-free period following the correct use of low-dose oral contraceptives and subsequent ovarian function during the administration of exogenous recombinant FSH (recFSH) after switching to continued Lyndiol® (2·5 mg lynestrenol + 0·05 mg ethinyl-oestradiol) medication. design Prospective, randomized, group-comparative, single-centre study. Following the monitoring of the pill-free period (week 1) and subsequent treatment with Lyndiol® (for a total of 5 weeks), all subjects were randomly allocated to one of four groups receiving daily FSH injections for 1 week [75, 150, 225 IU recFSH or 150 IU purified urinary FSH (uFSH)] during the fourth week of Lyndiol® use. patients Thirty-six healthy volunteers aged 18,39 years, prestudy oral contraceptive use for at least 3 months, cycle length between 24 and 35 days. measurements Serum FSH, LH and oestradiol (E2) concentrations as well as transvaginal ultrasound assessment of the number and diameter of follicles > 2 mm were used to monitor pituitary ovarian function. results At the start of the pill-free period following the prestudy contraceptive medication, 67% of the women presented with LH and FSH levels < 1 IU/l and only one follicle > 10 mm was observed. Initial levels of LH and FSH correlated (P < 0·05) with the extent of pituitary,ovarian activity during the pill-free period. At the end of the pill-free period a follicle > 10 mm had emerged in one subject only. During the first 3 days of Lyndiol® use, seven women (19%) eventually showed at least one follicle > 10 mm. During combined exogenous FSH and Lyndiol® administration, LH levels remained completely suppressed (, 0·5 IU/l) in all women studied. FSH levels and number and size of follicles increased with increasing doses of exogenous FSH in a dose-dependent manner. E2 levels remained low in all groups (< 150 pmol/l). During the week following FSH administration, FSH levels and E2 levels decreased gradually while the number of follicles > 10 mm still increased. conclusions We have confirmed that dominant follicles > 10 mm are present at the end of the pill-free period and during the first days after resumption of pill intake. Once follicles > 10 mm arose at the end of the pill-free period, continued use of Lyndiol® did not reduce follicle diameters. One week of Lyndiol® reduces pituitary,ovarian activity to levels observed after 3 weeks of low-dose pills. FSH administration during Lyndiol® resulted in dose-dependent follicle growth despite extremely low LH levels. E2 secretion (56 ± 51 pmol/l) occurred to a limited and variable extent along with extremely low serum LH concentrations. Recovery of pituitary,ovarian activity at the end of the pill-free period is comparable to FSH levels and follicle dynamics following 7 days of 75,150 IU/l recFSH. [source] | |||||||||||||