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1
Thumes, M., M. Holsteg, K. Failing, H. Bostedt e R. Hospes. "Über die Effektivität von DL- im Vergleich zu D-Cloprostenol bei Milchrindern mit einem Corpus luteum periodicum oder Corpus luteum persistens". Tierärztliche Praxis Ausgabe G: Großtiere / Nutztiere 33, n. 06 (2005): 395–403. http://dx.doi.org/10.1055/s-0038-1624086.
Testo completoAbstract (sommario):
Zusammenfassung Ziel der Untersuchung: Überprüfung der Wirksamkeit von DL-Cloprostenol vs. D-Cloprostenol in der Östrusinduktion bei Milchrindern. Probanden und Methoden: Das Probandenkollektiv umfasste 134 Rinder im Durchschnittsalter von 4,0 ± 0,5 Jahren (99 in Laktation, 35 Färsen). Vor alternierender Injektion zweier Cloprostenolpräparate (Gruppe A: DL-Cloprostenol, 500 μg, n = 70; Gruppe B: D-Cloprostenol, 150 μg, n = 64) wurde die Progesteronkonzentration im Serum bestimmt. Gynäkologische Kontrollen erfolgten 0–3 d post injectionem (p. inj.), wobei die als inseminationsfähig beurteilten Probanden (n = 123) am dritten Tag besamt wurden. Ergebnisse: In beiden Gruppen kam es bis zum dritten Tag p. inj. zu einer deutlichen Konsistenzänderung oder Regression der Corpora lutea (p ≤ 0,001). Die Lysis eines C. l. periodicum verlief bei Kühen markanter als bei Färsen (p ≤ 0,017). Insgesamt war D-Cloprostenol dem DL-Cloprostenol hier leicht überlegen. Am dritten Tag p. inj. wiesen 67,1% (A) bzw. 71,9% (B) der Probanden gut ausgeprägte Östrusanzeichen auf. Als inseminationsfähig wurden 94,3% (A) und 89,1% (B) der Tiere eingestuft. Ein geringer Präparateunterschied bestand hinsichtlich des Graviditätsresultates. Bei einem C. l. persistens verlief die Regression weniger progressiv als bei einem C. l. periodicum (p ≤ 0,024). Signifikante Wechselwirkungen zwischen den Einflussfaktoren Präparat und Indikation einerseits sowie für die übrigen gynäkologischen Kriterien andererseits ergaben sich nicht. Bei den Probanden mit prostaglandininduziertem Zyklus nach einem C. l. persistens lag die Graviditätsrate nach der 1. KB deutlich niedriger (31,9%) als bei Tieren nach Lysis eines C. l. periodicum (52,4%, p = 0,08). Schlussfolgerungen und klinische Relevanz: Der Einsatz von D-Cloprostenol erbringt im Wesentlichen die Resultate wie der von DL-Cloprostenol. Eine Überlegenheit konnte jedoch für die Progressivität der lytischen Wirkung des D-Cloprostenols festgestellt werden. Kühe mit C. l. persistens reagierten präparateunabhängig weniger intensiv als solche mit C. l. periodicum.
2
McCoy, M. A., S. D. Lennox, C. S. Mayne, W. J. McCaughey, H. W. J. Edgar, D. C. Catney, M. Verner, D. R. Mackey e A. W. Gordon. "Milk progesterone profiles and their relationship with fertility, production and disease in dairy cows in Northern Ireland". Animal Science 82, n. 2 (aprile 2006): 213–22. http://dx.doi.org/10.1079/asc200526.
Testo completoAbstract (sommario):
AbstractA detailed investigation was conducted to identify the main factors influencing the current poor reproductive performance in dairy herds in Northern Ireland. Nineteen herds were selected and a comprehensive database was established, comprising detailed information collected over a 2-year period. Milk progesterone monitoring (no.=1423 cows), based on twice weekly sampling, was included in this on-farm investigation. The mean interval from calving to commencement of luteal activity was 30·1 days and 13·4% (184/1378) of these cows had not commenced luteal activity by day 50post partum. In addition, there was a high incidence of abnormal progesterone profiles: delayed ovulation type I; 15·6% (242/1388), delayed ovulation type II; 11·7% (125/965), persistent corpus luteum type I; 19·4% (212/1121) and persistent corpus luteum type II; 11·9% (70/619). Delayed commencement of luteal activity and abnormal profiles were associated with reduced fertility performance manifested as increased interval to first AI service and ultimately prolonged calving interval. Delayed commencement of luteal activity and abnormal progesterone profiles, with the exception of ‘delayed ovulation type II’ profiles, were not associated with lower conception rates. Assistance at calving was associated with delayed commencement of luteal activity. Delayed commencement of luteal activity and delayed ovulation types I and II profiles were associated with indicators of nutritional stress and poorer production performance in early lactation. Retained foetal membranes were strongly associated with prolonged luteal phases (persistent corpus luteum types I and II profiles). While hormonal therapy may prove useful in treating cows with abnormal milk progesterone profiles, the prevention and treatment of associated diseases and the implementation of good management practices are likely to be more rewarding.
3
Hooper, S. B., e G. D. Thorburn. "Prostaglandin F2α and oxytocin release during persistence of the corpus luteum in sheep". Acta Endocrinologica 115, n. 4 (agosto 1987): 469–77. http://dx.doi.org/10.1530/acta.0.1150469.
Testo completoAbstract (sommario):
Abstract. Oxytocin (OT), progesterone and prostaglandin F2α (PGF2α) concentrations were measured in the utero-ovarian vein (UOV) of ewes which displayed persistence of the corpus luteum (CL). During the period of expected luteolysis, the frequency of OT and PGF2α pulses in the UOV was significantly (P < 0.005 for both) lower in ewes with persistent CLs, compared with ewes that underwent normal luteal regression. In contrast, the amplitude of both OT and PGF2α pulses was similar in both groups of animals. It is suggested that persistence of the CL resulted from a decreased PGF2α pulse frequency, which may have arisen from a decreased frequency of stimulation by OT. In two persistent CL ewes, however, it appeared that a failure at the level of the uterus may have contributed to the observed decrease in PGF2α release. Although a PGF2α analogue (Lutalyse) infusion into the uterine vein of two ewes with persistent CLs failed to induced luteolysis, it did stimulate a large release of OT into the UOV. This suggests that persistent CLs maybe more resistant to PGF2α and, that at day 22 post-oestrus, these CLs are capable of releasing large quantities of OT into the UOV.
4
Bramley, T. A., G. S. Menzies, A. S. McNeilly e H. G. Friesen. "Receptors for lactogenic hormones in the ovine corpus luteum. I: A major discrepancy in the specific binding of radiolabelled ovine prolactin and human growth hormone". Journal of Endocrinology 113, n. 3 (giugno 1987): 365–74. http://dx.doi.org/10.1677/joe.0.1130365.
Testo completoAbstract (sommario):
ABSTRACT The characteristics of the binding of 125I-labelled human GH (hGH) and ovine prolactin (oPRL) were studied in the ovine corpus luteum. Although oPRL is the homologous ligand for sheep lactogenic receptors, its binding was significantly and consistently lower than that of 125I-labelled hGH. This was not due to iodination damage of oPRL since: (1) 125I-labelled oPRL tracers which bound poorly relative to 125I-labelled hGH in the ovine corpus luteum were equipotent in the pig and rat corpus luteum, (2) the differences between 125I-labelled hGH and oPRL binding persisted with tracers of equivalent biopotency and (3) the iodination procedure affected neither oPRL bioactivity in the Nb2 tumour assay nor its binding activity with ovine corpus luteum receptors. Ovine luteal receptors were specific for lactogenic hormones. The specific binding of 125I-labelled hGH or oPRL could be inhibited completely by incubation with either unlabelled hormone, with similar potencies. However, oGH inhibited binding only at much higher concentrations, consistent with its known contamination with oPRL. Moreover, 125I-labelled oGH was not bound specifically to sheep luteal tissue. Fractionation of sheep luteal homogenates on sucrose density gradients (with or without cell-surface membrane perturbation by digitonin) demonstrated that binding of 125I-labelled hGH and 125I-labelled oPRL peaked in the same regions of the gradients, coincident with a number of luteal cell-surface membrane markers. We conclude that the marked discrepancy between the binding of hGH and oPRL tracers by sheep luteal tissue was not due to iodination damage of oPRL, binding of 125I-labelled hGH to somatogenic receptors or differential binding to luteal cell-surface versus intracellular receptors. J. Endocr. (1987) 113, 365–374
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Bu, Shumin, Chenfu Cao, Yongjun Yang, Chenglin Miao, Zeng Hu, Yujing Cao, Qingxiang Amy Sang e Enkui Duan. "Localization and temporal regulation of tissue inhibitor of metalloproteinases-4 in mouse ovary". Reproduction 131, n. 6 (giugno 2006): 1099–107. http://dx.doi.org/10.1530/rep.1.00810.
Testo completoAbstract (sommario):
Tissue inhibitors of metalloproteinases (TIMPs) are potential regulators of tissue remodeling in the ovary. The aim of the present study was to examine the localization and temporal regulation of TIMP-4 protein in the mouse ovary. An induced superovulation model (eCG/hCG) was employed in immature mice to evaluate TIMP-4 protein expression profiles in ovaries collected during the follicular phase, the pre ovulatory period, and the luteal lifespan. Immunofluorescence results indicated that TIMP-4 protein was localized to theca of both antral and preovulatory follicles and adjacent ovarian stroma. After the initiation of luteinization with hCG, TIMP-4 was observed within the luteinizing granulosa cells and persisted throughout the lifespan of the corpus luteum. In the cycling ovary, TIMP-4 signaling localized to corpus luteum from previous estrous cycles, the theca of preovulatory follicles, and appeared to be lower in newly forming corpus luteum. Western analysis further showed that the levels of TIMP-4 increased significantly during the luteinization process of granulosa cells, but no significant change was found among all corpus luteum stages. A putative regulatory mechanism of TIMP-4 expression was identified utilizing an in vitro model. Treatment of cultured granulosa cells with hCG significantly augmented TIMP-4 protein expression levels. Together our data indicate that the luteinization process of granulosa cells is associated with up-regulation of TIMP-4 and that TIMP-4 might play an essential role in maintenance of the luteal function during the whole lifespan of corpus luteum.
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Bagnell, C. A., Q. Zhang, K. Ohleth, M. L. Connor, B. R. Downey, B. K. Tsang e L. Ainsworth. "Developmental expression of the relaxin gene in the porcine corpus luteum". Journal of Molecular Endocrinology 10, n. 1 (febbraio 1993): 87–97. http://dx.doi.org/10.1677/jme.0.0100087.
Testo completoAbstract (sommario):
ABSTRACT Northern analysis and in-situ hybridization were used to follow the development of relaxin gene expression in the newly forming corpus luteum (CL) after ovulation and throughout luteal development. Alkaline phosphatase (AP) was used as a marker of theca-derived lutein cells and the relationship between AP-positive and relaxin mRNA-containing cells was assessed. Ovaries from prepubertal pigs treated with pregnant mares serum gonadotrophin (PMSG)/human chorionic gonadotrophin (hCG) were collected during the periovulatory period and at various times during 19 days after ovulation. In addition, CL from cyclic pigs on days 10 and 16 were used to monitor relaxin gene expression in small and large luteal cells. Northern analysis revealed that relaxin gene expression increased with CL development in the PMSG/hCG-treated pig, reaching maximal levels at around day 14 post-ovulation. Thereafter, as the CL regressed, the level of relaxin mRNA declined. In CL from cyclic pigs at day 10 of the cycle, only small luteal cells expressed relaxin mRNA. However, by day 16 of the cycle, large luteal cells were the source of relaxin gene expression. In-situ hybridization studies revealed that in the early CL (up to 30 h post-ovulation), the relaxin gene transcript was observed in cells along the margins of the CL and in the core of the infolding follicle wall corresponding to the AP-positive, luteinized theca cell layer. As luteinization progressed, the theca and granulosa cell layers could no longer be distinguished morphologically (from 54 h after ovulation until day 9). However, the pattern of relaxin hybridization persisted along the periphery in bands of cells penetrating the CL, and coincided with areas of AP staining, indicating that the theca lutein cells were the site of relaxin gene expression. At day 14, relaxin hybridization and AP staining were distributed throughout the luteal tissue. With CL regression both AP staining and relaxin hybridization declined. This pattern of relaxin hybridization in the CL of the gonadotrophin-primed pig was identical to that observed in cyclic pigs on days 10 and 16 of the cycle. These findings indicate that theca interna cells retain their ability to express the relaxin gene following ovulation and luteinization. In the early CL, the small theca-derived lutein cells are the source of relaxin transcript. However, as the CL becomes fully differentiated, the large granulosa-derived lutein cells acquire the capacity to express the relaxin message.
7
Sernia, C., R. T. Gemmell e W. G. Thomas. "Oxytocin receptors in the ovine corpus luteum". Journal of Endocrinology 121, n. 1 (aprile 1989): 117–23. http://dx.doi.org/10.1677/joe.0.1210117.
Testo completoAbstract (sommario):
ABSTRACT There is inconclusive evidence that oxytocin acts directly on the corpus luteum and affects steroidogenesis. Since any such action would probably be mediated by oxytocin receptors, these should be present in luteal tissue. In this study, homogenates of corpora lutea from both pregnant and non-pregnant ewes were examined for oxytocin receptors by radio-receptor assay. Specific oxytocin binding was not observed in luteal tissue during the oestrous cycle. However specific binding was found in the corpora lutea of pregnant ewes; appearing at a fetal head length of approximately 0·65 cm (about 30 days of pregnancy) and persisting to a head size of 11 cm, the largest size examined in this study. The affinity (Kd) of the receptor was calculated as 2·9 ± 0·3 nmol/l (s.e.m.; n = 9), a value similar to that obtained for the uterus. The receptor number ranged from a low of 8·7± 3·2 fmol/mg protein (n = 6) at a head size of <0·65 cm, to a maximum of 40·1 ± 6·5 fmol/mg protein (n = 25) at a head size of 2·5–3·75 cm. These values were lower than our estimate of 588 ± 39 fmol/mg protein (n = 5) for the uterus. It is concluded that a direct action of oxytocin on the corpus luteum is possible but only after the first month of pregnancy and not in the corpus luteum of the oestrous cycle. Journal of Endocrinology (1989) 121, 117–123
8
Santos, V. G., E. M. Bettencourt e O. J. Ginther. "Hormonal, luteal, and follicular changes during initiation of persistent corpus luteum in mares". Theriogenology 83, n. 4 (marzo 2015): 757–65. http://dx.doi.org/10.1016/j.theriogenology.2014.11.009.
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Bagavandoss, P. "Differential distribution of gelatinases and tissue inhibitor of metalloproteinase-1 in the rat ovary". Journal of Endocrinology 158, n. 2 (1 agosto 1998): 221–28. http://dx.doi.org/10.1677/joe.0.1580221.
Testo completoAbstract (sommario):
The distribution of gelatinases/matrix metalloproteinases-2 and -9 (MMP-2 and MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in neonatal and gonadotropin-primed immature rat ovaries was studied by immunofluorescent microscopy. Immature female Long-Evans rats were primed with 15 IU pregnant mare's serum gonadotropin (PMSG) in 100 microliters PBS. Two days later, to induce ovulation, the rats were injected with human chorionic gonadotropin (hCG, 5 IU/100 microliters PBS). The animals were killed at appropriate times and the ovaries removed and processed for cryostat or paraffin sectioning. Ovaries were also obtained from 7-day-old neonatal rats and processed as above. In the neonatal rat ovary, MMP-2 was present in the follicle and in the ovarian surface epithelium. MMP-9 was not detectable in the neonatal ovary. TIMP-1 was present in the oocyte and in the surface epithelium. In the PMSG-primed ovary, MMP-2 was present in the granulosa and thecal cells of the ovary. MMP-9 distribution, however, was restricted to the interstitial and thecal cells. TIMP-1 was mainly present in the blood vessels and thecal cells, with minor staining in the granulosa cells. In the developing corpus luteum, luteal and endothelial cells were positive for MMP-2. MMP-9 localization was restricted to the plasma membrane of the luteal and interstitial cells. TIMP-1 was clearly observed in the luteal capillaries and, to a lesser extent, in the luteal cell plasma membrane. This distribution of MMP-2, MMP-9, and TIMP-1 in the corpus luteum persisted throughout the life span of the corpus luteum. The spatial and temporal distribution of the gelatinases and TIMP-1 suggests unique roles for these proteins in the rat ovary.
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G. P. Dyulger, A. A. Stekolnikov, K. O. Shatsky, L. B. Leontev, P. G. Dyulger, E. S. Sedletskaya, E. S. Latynina e I. V. Akchurina. "PATHOPHYSIOLOGICAL ASPECTS OF GOAT FALSE PREGNANCY (HYDROMETRA) AND MODERN METHODS OF ITS DIAGNOSIS AND THERAPY". BULLETIN 1, n. 383 (15 febbraio 2020): 49–55. http://dx.doi.org/10.32014/2020.2518-1467.6.
Testo completoAbstract (sommario):
The article considers the unique, not described in the domestic scientific and educational literature, the dishormonal pathology of the reproductive sphere of goats. The disease is characterized by prolonged anaphrodisia, the persistence of one or more functionally active corpus luteum in the ovaries and hydrometra - volumetric increase in the size of the uterus due to effusion of sterile serous fluid into its cavity. Hydrometra is a leading diagnostic sign of the disease. The research aimed to analyze the data of foreign literature on epidemiology, pathophysiology, diagnostics, and therapy of false pregnancy (hydrometra) in goats. Based on the analysis of foreign literature data, the epidemiological characteristics of the disease were determined. It was found that the hydrometra is a fairly common pathology and is recorded on average in 4.2% of goats. The risk group includes goats aged 6...8 years and older. A hereditary (familial) predisposition of milk goats to the development of hydrometra was revealed. Iatrogenic factors also have a significant effect on the frequency of incidence: hormonal treatment of goats during and/or out the estrous season with progestins alone or in combination with gonadotropin in the serum of mares. The etiology of pseudopregnancy, as well as the cause-effect relationship between the persistence of the corpus luteum and the development of hydrometra have not been fully established. Retention of the corpus luteum always precedes and accompanies the development of hydrometra. Spontaneous regression of the persistent corpus luteum leads to interruption of pseudopregnancy and emptying of hydrometra. Violation of the external regulation with prostaglandin of the functional activity of the corpus luteum, apparently, plays a pivotal role in the pathogenesis of the disease. According to the profile of progesterone in the blood, it was found that the duration of false pregnancy is an average of 150.3±23.5 days. Visual echography is the main diagnostic method of false pregnancy. The diagnosis of the disease is based on the detection of hypoechoic fluid in the uterine cavity in the absence of placentas and fetuses in the uterus. Prostaglandin therapy is a pathogenetically substantiated and quite effective method of treating hydrometra.
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Geva, Eli, Giora Gottesman, Liat Lemer-Geva, Ruth Lang, Meir Pomeranz, Vivian Barak e Baruch Wolach. "Secondary amenorrhoea due to persistent corpus luteum in brucellosis". Lancet 345, n. 8943 (gennaio 1995): 201. http://dx.doi.org/10.1016/s0140-6736(95)90211-2.
Testo completo
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Santos, V. G., E. M. V. Bettencourt e O. J. Ginther. "Long-term characteristics of idiopathic persistent corpus luteum in the mare". Theriogenology 84, n. 2 (luglio 2015): 242–51. http://dx.doi.org/10.1016/j.theriogenology.2015.03.015.
Testo completo
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Mushtaq, H. Lashari, e Tasawar Zahida. "The effect of PGF2 on persistent corpus luteum in Sahiwal cows". International Journal of Livestock Production 3, n. 1 (31 gennaio 2012): 1–5. http://dx.doi.org/10.5897/ijlp10.012.
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Marnet, Pierre-Guy, e Jacques Labussière. "Intramammary pressure and luteal oxytocin after PGF2α administration in cycling and early pregnant ewes". Journal of Dairy Research 61, n. 3 (agosto 1994): 345–53. http://dx.doi.org/10.1017/s0022029900030764.
Testo completoAbstract (sommario):
SummaryThe aim of this work was to investigate whether luteal oxytocin released after non-luteolytic prostaglandin F2α (PGF2α) challenge could explain the intramammary pressure (IMP) rises previously described in pregnant ewes after the normal life span of a corpus luteum. Blood oxytocin levels and IMP after challenge were measured in cycling and pregnant lactating ewes until the response ceased (˜ 55 d post oestrus). Oxytocin release was not significantly different for cycling and pregnant ewes, and fell to its lowest levels on days 16–18 post oestrus in both groups, i.e. with or without luteolysis. However, although IMP response fell with luteolysis in cycling ewes, the response persisted until day 55 in pregnant ewes. This lack of correlation between oxytocin release and IMP response raised interesting questions including: is there an unknown oxytocic compound that can be released after PGF2α stimulation of the corpora lutea?
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Potapov, V. O. "Biological role of nitric oxide donors in pregravid preparation of women with luteal phase deficiency". Infusion & Chemotherapy, n. 3.2 (15 dicembre 2020): 247–49. http://dx.doi.org/10.32902/2663-0338-2020-3.2-247-249.
Testo completoAbstract (sommario):
Background. At the menstrual cycle beginning there is a proliferation of endometrial cells under the influence of oestrogen, and in the second half, after ovulation there is a differentiation and hypertrophy of cells under the influence of corpus luteum progesterone. Lutein phase deficiency (LPD) can be divided into 3 types: lack of progesterone production (corpus luteum is absent), low progesterone level (corpus luteum hypofunction), and reduction of progesterone production period (short period of corpus luteum existence, luteal phase duration <11 days).
Objective. To describe the role of nitric oxide (NO) donors in women with LPD.
Materials and methods. Analysis of literature data on this issue.
Results and discussion. The main adverse outcome of LPD is the absence or defective transformation and reception of the endometrium required for successful fertilization of the egg. In case of progesterone deficiency, the depth of trophoblast invasion decreases, resulting in abnormal placental development and inadequate uteroplacental blood flow. The latter can further lead to antenatal foetal death and miscarriage, preeclampsia and eclampsia, placental dysfunction. LPD should be suspected in patients with infertility, abnormal uterine bleeding, severe premenstrual syndrome, endometrial hyperplasia, and habitual miscarriage. Ultrasound signs of LPD include the absence of a dominant follicle, absence of ovulation in the presence of a mature follicle (persistence), absence of corpus luteum in the 2nd phase of the cycle, endometrial thickness in the secretion phase <9 mm, increased echogenicity only in the peripheral parts of the endometrium or three-layered endometrium. Functional tests for the detection of LPD include the basal temperature measurement and examination of smears (hypolutein type of smear, preservation of the symptom of cervical mucus crystallization in the 2nd phase of the cycle). A key element of pregravid preparation for women with LPD is the progesterone donation (in oil solution, in etiloleate or micronized). The therapeutic efficacy of different commercial progesterone drugs is the same. Progesterone helps to prepare the endometrium for trophoblast invasion and promotes uterine hypotension. Incomplete secretory transformation of the endometrium during the treatment with progesterone drugs occurs in case of inadequate blood supply to the endometrium due to low density of functional vessels or insufficient content of NO in the endometrium. Back in the late 90’s of last century, it was shown that NO acts as a powerful uterine relaxant, and reduction of its concentration leads to miscarriage. In humans, NO is produced from L-arginine, however, obtaining the required dose of the latter with food is not always possible. When L-arginine (Tivortin aspartate, “Yuria-Pharm”) is used as a NO donor, peripheral vascular dilatation and neoangiogenesis occur, which improves blood supply and endometrial trophic processes; stimulation of gene transcription and cell cycle, which increases the cell population and physiological thickness of the endometrium; regulation of sex hormone synthesis and expression of their receptors, which increases the receptivity of the endometrium. The regimen of Tivortin aspartate administration is the following: 5 ml (1 g) 6 times per day during the menstrual cycle. According to the results of our own study, L-arginine increases the biological effect of progesterone on the endometrium, promotes a more successful restoration of its physiological structure and thickness in women with LPD. The inclusion of L-arginine in the pregravid preparation of women with LPD showed a 1.9-fold decrease in the infertility incidence, a 3.3-fold increase in the number of pregnancies and births, and a 3.4-fold decrease in the number of miscarriages.
Conclusions. 1. The main adverse outcome of LPD is the absence or defective transformation and reception of the endometrium required for successful fertilization of the egg. 2. Usage of L-arginine (Tivortin aspartate) as a donor of NO promotes dilatation of peripheral vessels and neoangiogenesis, stimulation of the cell cycle, regulation of the synthesis of sex hormones. 3. Inclusion of L-arginine in the pregravid preparation of women with LPD leads to the decrease in infertility, to the increase in the number of pregnancies and births and to the decrease in the number of miscarriages.
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Ginther, O. J., T. Castro, J. M. Baldrighi, C. A. Wolf e V. G. Santos. "Defective secretion of Prostaglandin F2α during development of idiopathic persistent corpus luteum in mares". Domestic Animal Endocrinology 55 (aprile 2016): 60–65. http://dx.doi.org/10.1016/j.domaniend.2015.10.004.
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Dingwall, W. S., W. A. C. McKelvey, F. E. Gebbie e J. J. Robinson. "The incidence of elevated progestrone at the time of insemination in Suffolk ewes bred in August". Proceedings of the British Society of Animal Science 1996 (marzo 1996): 188. http://dx.doi.org/10.1017/s0308229600031548.
Testo completoAbstract (sommario):
The development of laparoscopic intrauterine insemination for sheep has been essential for the implementation of national Sire Reference Schemes in the UK (McKelvey and Simm, 1995). Whilst conception rate to artificial insemination (AI) has averaged 60-70% in most participating flocks, a number of flocks have experienced a proportion of their ewes returning to anoestrus following AI. This phenomenon restricts the implementation of sire reference schemes and it has been proposed that die causal factor could be the presence of a persistent corpus luteum at the time of insemination.
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Gemmell, R. T. "The persistence of the corpus luteum of pregnancy into lactation in the marsupial bandicoot, Isoodon macrourus". General and Comparative Endocrinology 75, n. 3 (settembre 1989): 355–62. http://dx.doi.org/10.1016/0016-6480(89)90170-6.
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Balogh, Orsolya, Ernő Túry, Zsolt Abonyi-Tóth, John Kastelic e György Gábor. "Macroscopic and histological characteristics of fluid-filled ovarian structures in dairy cows". Acta Veterinaria Hungarica 62, n. 2 (1 giugno 2014): 215–32. http://dx.doi.org/10.1556/avet.2013.047.
Testo completoAbstract (sommario):
The primary objective of this study was to use macroscopic and histological features of corpora lutea with a cavity and anovulatory cystic ovarian structures, present in 90 pairs of abattoir-derived dairy cow ovaries, as the basis to clarify the nomenclature of ovarian structures. Excluding morphologically normal ovarian fol-licles (antrum < 2 cm, wall < 1 mm), there were 27 fluid-filled ovarian structures. Ovulatory structures > 16 mm in diameter were designated as Group A (cavity ≤ 10 mm and wall > 10 mm) or Group B (cavity > 10 mm and wall < 10 mm). The volume of luteal tissue was less (P < 0.05) in Group B than in Group A, whereas that of a solid corpus luteum (CL) was intermediate (least square means ± SEM: 72 ± 1.92, 11.22 ± 1.57 and 5.84 ± 1.92 cm3, respectively). There was a greater proportion (P < 0.05) of small luteal cells in Group B compared to a solid CL, whereas Group A was intermediate (58.6 ± 5.3, 37.4 ± 5.3 and 44.0 ± 4.4%, respectively). Connective tissue was thicker (P < 0.05) in Group B than in Group A (295.4 ± 46.9 vs. 153.9 ± 38.2 μm). Based on the above-mentioned characteristics and differences, Groups A and B were designated as a CL with a cavity and a cystic CL, respectively. Furthermore, there were three groups of anovulatory ovarian structures. Structures in Group C were termed persistent/anovulatory follicles (overall diameter and wall thickness ≤ 20 and 1–3 mm, respectively). Finally, Groups D and E were designated as a follicle-fibrous cyst and a follicle-luteinised cyst (based on histological structure) for anovulatory structures with an overall diameter and wall thickness of ≥ 20 and ≤ 3 mm, and ≥ 20 and ≥ 3 mm, respectively.
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Beard, A. P., S. Madgwick, K. M. Quinn e A. C. O. Evans. "Synchronisation of oestrus using a 14 day progestagen sponge treatment in the absence of a corpus luteum does not reduce fertility in ewes". Proceedings of the British Society of Animal Science 2001 (2001): 222. http://dx.doi.org/10.1017/s1752756200006049.
Testo completoAbstract (sommario):
Progesterone and progestagens are widely used to synchronise oestrus in sheep, however 15 to 30 % of ewes fail to maintain a pregnancy following the first service after oestrous synchronisation and the reason(s) for this failure rate is unclear. In commercial flocks, the progestagen treatment commences at a random stage of the oestrous cycle and in some ewes luteolysis may occur soon after treatment commences, leaving the ewe solely dependent on the exogenous source of progestagen which promotes the development of persistent follicles (Flynn et al., 2000). These persistent follicles may be up to 14 days of age when they ovulate whereas the age of follicles at ovulation in natural cycles is 4 to 8 days. In cattle, it is clear that ovulation of these old follicles results in a decrease in fertility. The aim of this study was to examine the effect of ovulation of aged follicles on fertility in cyclic ewes by using treatments based on a 14-day, progestagen synchronisation protocol that is known to produce persistent follicles.
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Taylor, VJ, DE Beever, MJ Bryant e DC Wathes. "First lactation ovarian function in dairy heifers in relation to prepubertal metabolic profiles". Journal of Endocrinology 180, n. 1 (1 gennaio 2004): 63–75. http://dx.doi.org/10.1677/joe.0.1800063.
Testo completoAbstract (sommario):
The aim of this study was to determine whether any differences in the GH-IGF-I axis in juvenile calves were predictive of fertility problems as adult cows. Endogenous metabolic hormone profiles before and after feeding and the response to a GH-releasing factor (GRF) challenge were measured in prepubertal (6 month) dairy calves. These metabolic parameters were subsequently related to physical characteristics at puberty and to ovarian function during the first lactation. Milk progesterone analysis was used to categorize the animals into those with normal progesterone profiles following calving (n=17) and those that developed delayed ovulation (DOV1, n=9) or persistent corpus luteum (PCL1, n=6) profiles. There were associations between prepubertal GH parameters, glucose and non-esterified fatty acid (NEFA) concentrations and the body condition score at which the animals attained puberty. The calves which subsequently developed DOV1 profiles as cows tended to have a higher GH pulse amplitude during fasting than normal profile animals, they did not show the anticipated decrease in circulating glucose concentrations following a post-prandial rise in insulin and they also had the lowest IGF-I concentrations. The calves that later developed PCL1 had a significantly larger GH pulse amplitude and pulse area than normal profile animals in the fed period and had the highest IGF-I concentrations. There were no differences in prepubertal insulin or NEFA concentrations or in the GH response to a GRF challenge between the different progesterone profile categories. Plasma IGF-I concentrations in prepubertal animals were positively correlated with their post-calving concentrations, whereas glucose concentrations had a negative correlation between these time-periods. These results suggested that the different juvenile endocrine profiles of the DOV1 cows may predispose them to a higher rate of tIssue mobilization during lactation and a consequent reduction in fertility, while altered GH and IGF-I levels in PCL1 cows may later contribute to the maintenance of the persistent corpus luteum. Therefore metabolic differences in prepubertal calves were later reflected by altered reproductive function during the first lactation.
22
Azwani, Nabila, Pudji Srianto, Sri Pantja Madyawati, Trilas Sardjito e Endang Suprihati. "Angka kebuntingan sapi perah dengan korpus luteum persisten setelah pemberian kombinasi prostaglandin F2α dan gonadotropin". Ovozoa : Journal of Animal Reproduction 10, n. 2 (17 agosto 2021): 59. http://dx.doi.org/10.20473/ovz.v10i2.2021.59-64.
Testo completoAbstract (sommario):
This case study aims to determine the effect of a combination of prostaglandin F2α (PGF2α) with Gonadotropin (PG-600), and human chorionic gonadotropin (hCG) on the estrus and pregnancy rates in Holstein Friesian (HF) cows with persistent corpus luteum (PCL). A total of 15 Holstein Friesian (HF) dairy cows aged 3-5 years with body condition score (BCS) 5-7 (scale 1-9) diagnosed with PCL, were injected with 7.5 mg PGF2α intra-vulvar submucosa. Cows were then divided into three treatment groups. Group P0 was not given the combination treatment, while P1 group was injected with a combination of 300 IU PG-600 and 150 IU hCG, meanwhile P2 group was was injected with a combination of 300 IU PG-600 and 300 IU hCG intra-muscularly. The PGF2α and PG-600 injections were carried out on the same day PCL was diagnosed. Meanwhile, the injection of hCG was carried out at the same time as the AI. The Pregnancy examination was performed 90 days after AI through rectal palpation. The results showed that all treated cows were estrus observed with the fastest onset of estrus was the P2 group, that was significantly different (p <0.05) compared to the P0 and P1 groups. All treated cows were diagnosed as pregnant. It can be concluded that the administration of PGF2α or its combination with gonadotropins in HF cows with PCL could result in 100% estrus and pregnancy rates.
23
VANDEVOORT, CATHERINE A., RICHARD L. STOUFFER, THEODORE A. MOLSKNESS e JOSEPH S. OTTOBRE. "Chronic Exposure of the Developing Corpus Luteum in Monkeys to Chorionic Gonadotropin: Persistent Progesterone Production Despite Desensitization of Adenylate Cyclase*". Endocrinology 122, n. 5 (maggio 1988): 1876–82. http://dx.doi.org/10.1210/endo-122-5-1876.
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TAKAHASHI, KIYOHARU, MASAHIRO CHIBA, HIDESHI TAKAHASHI e SHIGERU SATO. "Progesterone Levels, Induction of Estrus and Conception Rate in Cows with Persistent Corpus Luteum after Treatment with Prostaglandin F2^|^alpha;". Journal of the Japan Veterinary Medical Association 40, n. 4 (1987): 241–46. http://dx.doi.org/10.12935/jvma1951.40.241.
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25
Ginther, O. J., J. M. Baldrighi, T. Castro, C. A. Wolf e V. G. Santos. "Concentrations of progesterone, a metabolite of PGF2α, prolactin, and luteinizing hormone during development of idiopathic persistent corpus luteum in mares". Domestic Animal Endocrinology 55 (aprile 2016): 114–22. http://dx.doi.org/10.1016/j.domaniend.2015.12.004.
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26
Revunets, A. S., e S. B. Zarembliuk. "Cytology of smears of prints with symptomatic forms of infertility in cows". Scientific Messenger of LNU of Veterinary Medicine and Biotechnologies 22, n. 99 (28 ottobre 2020): 173–76. http://dx.doi.org/10.32718/nvlvet9926.
Testo completoAbstract (sommario):
Many works of domestic and foreign scientists are devoted to the study of etiological factors, pathogenesis, as well as the development of effective methods of diagnosis and therapy for symptomatic infertility of cows, however, insufficient attention is paid to cytological examination of the genital organs.So the goal of our work was to study the cytology of vaginal mucus at the symptomatic form of infertility of cows. The article presents the cytological composition of vaginal mucus from the mucous membrane of the caudal section of the cervix, the lateral surface of the vagina and the dorsal wall of the vaginal vestibule. Research was carried out with 5 groups of cows 4–5 years old cows 6 animals in each, weighing 500–600 kg, with an average productivity of 7500 kg of milk per lactation. The tests were cows were on the 18–24 day after insemination and during the sexual cycle braking, research of the joint course of uterus and hypotension of the ovarian, the presence of persistent corpus luteum and subclinical chronic endometritis, cysts and persistent corpus luteum of the ovarian body. For sub-clinical chronic endometritis, basal cells (32–41 %) are found in wet prep with vaginal mucosa, which are arranged in layers, parabasal (22–6 %) and superficial (5–21 %), but more interstitial (37–66 %), and bare neutrophil nuclei. According to hypofunction of ovaries in vaginal smears, neutrophils, vacuoles in interstitial cell nuclei (44–56 %), basophilic cells (30–43 %), superficial cells (20–21 %), parabasal cells (3–6 %). Basal cell hypofusions were (3–43%), parabasal (3–6 %), interstitial (44–56 %), superficial (20–21 %), and bilateral (12–26 %) (4–5 %) (36–55 %) and (30–33 %). It should be noted that for the functional state of the body, the cells from the cervix are flat. In addition, the drug contains single white blood cells with light cytoplasm without signs of phagocytosis. They are structurally similar to cells of vaginal smear. During the esrtus, the smear is dominated by interstitial and surface cells and white cells, and in the follicular proliferative phase, the number of surface cells increases, while the ovulator phase is characterized by the pronounced maturation of the cells, they are flat and spaced apart.
27
MENEGATOS (Ι. ΜΕΝΕΓΑΤΟΣ), J., S. CHADIO (Σ. ΧΑΔΙΩ), V. DOSOPOULOS (Β. ΔΟΣΟΠΟΥΛΟΣ), D. KALOGIANNIS (Δ. ΚΑΛΟΓΙΑΝΝΗΣ) e E. XYLOURI (Ε. ΞΥΛΟΥΡΗ). "Ovarian and thyroid activity of the Lacaune ewes breed during the year in Greece". Journal of the Hellenic Veterinary Medical Society 54, n. 3 (19 dicembre 2017): 209. http://dx.doi.org/10.12681/jhvms.15261.
Testo completoAbstract (sommario):
Ovarian and thyroid activity was studied in 10 ewes of Lacuane breed during one year. Ewes were maintained separately from rams and were fed. The aim of the study was to determine the duration of the anestrus period. Blood samples were collected weekly for the determination of progesterone levels. Thyroxine levels were also determined. Progesterone concentrations > 1 ng/ml were considered as indicative of ovulation, whereas levels between 0.5-0.9 ng/ml as indicative of follicle luteinizations or short lived corpus luteum. Two ewes showed persistent corpus luteum which regressed in deep anestrus period. The first ovulation occurred on 18th August ±10 days. The duration of the breeding season (the interval from the first to the last ovulation) was estimated to be 158 ± 8 days and the number of ovarian cycles during this period was 9.0 ± 0.6 per ewe. A significant correlation was observed between the time of the last ovulation and the duration of the breeding season, (Y=l4l.4+0.96X, r2 = 0.71, P<0.01). Serum thyroxine levels in every fifteen days samples fluctuate from 47 ± 4 during the first half of August to 82 ± 5 during the second half of December. Mean thyroxine levels during the time of increasing daylength (23rd December to 22nd June) were 71.2 ± 2 ng/ml and during that of decreasing daylength (23rd June to 22nd December) 59.4 ± 3 ng/ml, (p<0.001). In conclusion, this study showed that the ewes of the Lacaune breed exhibit a long anestrous period compared to the indigenous Greek breeds. Hormonal control of estrus is necessary for the out-of season lambing. Finally, thyroid function shows a significant seasonality, as has been demonstrated in all other breeds of sheep studied so far.
28
Dahham, Haddawi M. "Treatment of anoestrus local Iraqi buffaloes (Bubalus bubalis) using different hormones - field study". Iraqi Journal of Veterinary Medicine 38, n. 1 (1 giugno 2014): 121–23. http://dx.doi.org/10.30539/iraqijvm.v38i1.264.
Testo completoAbstract (sommario):
This study aimed to evaluate the efficacy of different hormonal treatments protocols (PGF2α ,GnRH, estradiol and progesterone) hormones on reproductive performance of postpartum anoestrus native dairy River buffaloes (Bubalus bubalis), endemic south of Baghdad under field conditions . Present study was conducted on 128 animals that had postpartum anoestrus (PPA) for a period between 4 to 8 months. The animals were subjected to two experiments according to the type of anoestrus. In the first experiment 94 animals (73.5%) with persistent corpus luteum on their ovaries without any signs of estrous (sub-oestrus) were classified into two sub-groups.Sub-group1 (n=47) treated with PGF2α hormone alone and sub-group 2 (n= 47) were treated by two injections. The first injection was PGF2α. while the second injection GnRH+ PGF2α was injected after 9 days.In second experiment 34 buffalo cows without any structure on their ovaries (True anestrous) were classified into two sub-groups according to design of the treatment. Sub-group 1(n=14) was treated with estradiol as single injection. Sub-Group 2(n=20) received estradiol + progesterone .The results indicated that the pregnancy rate in sub- groups1 and 2 of the first experiment were 85.1% and 89% respectively , which was not significantly differ from each other (P < 0.05). While in the second experiment, the pregnancy rate for the first and second sub- groups were 71% and 75%, respectively. This study concluded that the prevailing situation of anestrous in postpartum buffaloes endemic south of Baghdad is anestrous with corpus luteum (Sub-oestrus) , 94 out of 128 (73.5%) , and the most efficient treatment protocol of these case are PGF2α + GnRH hormones ( pregnancy rate= 89%) . While estradiol + progesterone treatment are efficient in the treatment of animals suffering from true anestrous (pregnancy rate 75%).
29
Flynn, J. D., P. Duffy, M. P. Boland e A. C. O. Evans. "Progestagen synchronisation in the absence of a corpus luteum results in the ovulation of a persistent follicle in cyclic ewe lambs". Animal Reproduction Science 62, n. 4 (settembre 2000): 285–96. http://dx.doi.org/10.1016/s0378-4320(00)00124-x.
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30
KOZDROWSKI, ROLAND, e KORNELIA OMYŁA. "Early embryonic death in mares: The causes, diagnosis and prevention". Medycyna Weterynaryjna 76, n. 12 (2020): 6469–2020. http://dx.doi.org/10.21521/mw.6469.
Testo completoAbstract (sommario):
The aim of this study was to describe the most important causes of early embryonic death (EED) in mares, as well as diagnostic methods and possible prevention procedures. Ageing and subclinical endometritis are described and discussed in detail as the most important causes of EED in mares. EED is also discussed in relation to foaling heat breeding and the time of insemination or natural cover. Other causes of EDD discussed in the study are progesterone deficiency due to primary corpus luteum dysfunction, mare’s weight loss, chromosomal abnormality and abnormal embryonic vesicle fixation. Positive effects can be achieved through maintaining ideal body condition, diagnosis and treatment of subclinical endometritis, appropriate care of the mare in the postpartum period, avoiding mating those mares that may ovulate before the 10th day after delivery, as well as monitoring the genital tract after mating for persistent post-breeding induced endometritis. Administration of altrenogest should be reserved for those cases in which endometritis has been ruled out as the cause of EED.
31
Bulling, Andreas, Frank D. Berg, Ulrike Berg, Diane M. Duffy, Richard L. Stouffer, Sergio R. Ojeda, Manfred Gratzl e Artur Mayerhofer. "Identification of an Ovarian Voltage-Activated Na+-Channel Type: Hints to Involvement in Luteolysis". Molecular Endocrinology 14, n. 7 (1 luglio 2000): 1064–74. http://dx.doi.org/10.1210/mend.14.7.0481.
Testo completoAbstract (sommario):
Abstract An endocrine type of voltage-activated sodium channel (eNaCh) was identified in the human ovary and human luteinized granulosa cells (GC). Whole-cell patch-clamp studies showed that the eNaCh in GC is functional and tetrodotoxin (TTX) sensitive. The luteotrophic hormone human CG (hCG) was found to decrease the peak amplitude of the sodium current within seconds. Treatment with hCG for 24–48 h suppressed not only eNaCh mRNA levels, but also mean Na+ peak currents and resting membrane potentials. An unexpected role for eNaChs in regulating cell morphology and function was indicated after pharmacological modulation of presumed eNaCh steady-state activity in GC cultures for 24–48 h using TTX (NaCh blocker) and veratridine (NaCh activator). TTX preserved a highly differentiated cellular phenotype. Veratridine not only increased the number of secondary lysosomes but also led to a significantly reduced progesterone production. Importantly, endocrine cells of the nonhuman primate corpus luteum (CL), which represent in vivo counterparts of luteinized GC, also contain eNaCh mRNA. Although the mechanism of channel activity under physiological conditions is not clear, it may include persistent Na+ currents. As observed in GC in culture, abundant secondary lysosomes were particularly evident in the regressing CL, suggesting a functional link between eNaCh activity and this form of cellular regression in vivo. Our results identify eNaCh in ovarian endocrine cells and demonstrate that their expression is under the inhibitory control of hCG. Activation of eNaChs in luteal cells, due to loss of gonadotropin support, may initiate a cascade of events leading to decreased CL function, a process that involves lysosomal activation and autophagy. These results imply that ovarian eNaChs are involved in the physiological demise of the temporary endocrine organ CL in the primate ovary during the menstrual cycle. Because commonly used drugs, including phenytoin, target NaChs, these results may be of clinical relevance.
32
MAGATA, Fumie, Koumei SHIRASUNA, Klaas STR^|^Uuml;VE, Kathrin HERZOG, Takashi SHIMIZU, Heinrich BOLLWEIN e Akio MIYAMOTO. "Gene Expressions in the Persistent Corpus Luteum of Postpartum Dairy Cows: Distinct Profiles from the Corpora Lutea of the Estrous Cycle and Pregnancy". Journal of Reproduction and Development 58, n. 4 (2012): 445–52. http://dx.doi.org/10.1262/jrd.2011-049.
Testo completo
33
Faigl, Vera, Mónika Keresztes, Alíz Márton, Hedvig Fébel, Margit Kulcsár, Sándor Nagy, Sándor Cseh, László Solti e Gyula Huszenicza. "Effect of season and photoperiod on the time of first postpartum ovulation in Awassi ewes". Acta Veterinaria Hungarica 59, n. 4 (1 dicembre 2011): 497–510. http://dx.doi.org/10.1556/avet.2011.036.
Testo completoAbstract (sommario):
Seasonal differences in the resumption of postpartum ovarian activity, milk production and periparturient metabolic status were investigated in lactating non-suckling dairy Awassi sheep in two consecutive experiments. In Experiment 1, autumn-lambing (AL, n = 27) and spring-lambing (SL, n = 37) ewes were investigated. Ovarian activity was monitored by means of individual progesterone (P4) profiles from day 5 to day 100 post partum. Most of the AL dams (89%) ovulated till day 35 after parturition and became cyclic thereafter. Incidence of persistent corpus luteum (CLP) and short luteal phases (sCL) was frequent (18% and 29%, respectively) among non-conceiving dams. In contrast, only 24% of the SL ewes ovulated before day 35. P4 levels during the luteal phase were lower in cyclic animals, and the cycle was longer in SL than in AL animals. No CLP or sCL was detected in the spring-lambing group, and 61% of SL ewes remained acyclic till the end of the trial. Lactation length was significantly longer in SL dams than in AL ewes (P = 0.008). According to the plasma metabolites (BHB, NEFA) and metabolic hormones (insulin, IGF-I, thyroxine) examined, negative energy balance did not appear in any of the animals. However, seasonal differences were seen in IGF-I and thyroxine levels, which were higher in the SL dams. In Experiment 2, influence of additional lighting was studied in autumn-lambing ewes. The long-day photoperiod (LD, n = 23) group was exposed to artificial light from sunset till midnight (approx. 16 h light/8 h dark) from some weeks before the expected date of delivery in mid-September until the end of December. The control group (n = 25) experienced only natural daylength. The first postpartum ovulation tended to occur later in the LD animals than in the controls (P = 0.047). The lactation of the LD group tended to be longer (P = 0.061). NEFA, BHB, insulin, IGF-I and thyroxine levels did not differ between the groups. Conclusions: (i) The ovarian function of the Awassi population is seasonal under temperate continental climate conditions. (ii) The first postpartum ovulation of non-suckling, autumn-lambing dams may occur very early, even before the completion of uterine involution. (iii) Additional artificial lighting may delay the time of first postpartum ovulation in AL ewes. (iv) Postpartum negative energy balance is unlikely to occur in dairy Awassi ewes even in high-producing intensive systems.
34
Pestis, V. K., L. V. Golubets e A. S. Deshko. "Assisted reproductive technologies in cattle reproduction and selection". Proceedings of the National Academy of Sciences of Belarus. Agrarian Series 57, n. 2 (18 maggio 2019): 192–203. http://dx.doi.org/10.29235/1817-7204-2019-57-2-192-203.
Testo completoAbstract (sommario):
In vitro technology is one of the most dynamically developing and more and more stable biotechnological methods today accelerating selection, intensifying reproductive and genetic potential of breeding animals, allowing to increase breeding young animals production by one champion cow up to 5–10 calves per year, reduce generation interval and significantly accelerate process of updating and qualitative improvement of livestock. However, obtaining oocytes competent for in vitro development is one of the critical factors determining success of the method and depending on a number of biological and technical factors. This paper presents results of studies on effect of biological factors of direct and indirect impact on efficiency of obtaining oocytes in the system of transvaginal aspiration for the first time conducted in the Republic of Belarus. Yield of excellent and good quality oocytes increased during aspiration during the luteal phase of estrous cycle and remained almost unchanged during aspiration into the follicular phase. Presence of follicles with diameter over 8 mm in the ovaries during aspiration reduced yield of excellent and good quality oocytes averagely by 9.4 percentage points. Removing the dominant follicle 72 hours prior to aspiration allowed increasing the number of aspirated follicles by 41 %, and yield of oocytes – by 22.9 %. Microstimulation of ovaries prior to aspiration by follicle-stimulating hormones FSG-super and Plusset increased efficiency of aspiration in terms of the main indicators by 19.2–45.9 %. Follicular cyst or persistent corpus luteum in one of the ovaries reduced both quantitative and qualitative indicators of aspiration. The data obtained are of practical importance for development of technology for in vitro embryo production in the system of transvaginal aspiration of oocytes which will help to accelerate breeding process and increase efficiency of breeding work in livestock production in general.Acknowledgments. The research was conducted within the two state research programs: “Biotechnology”, subprogram “Development of biological science, biological education and biological industry for 2007–2011 and for the period up to 2020”, “High technologies and equipment for 2016-2020”, subprogram 1 “Innovative biotechnologies–2020”.
35
Luck, M. R., e B. Jungclas. "The time-course of oxytocin secretion from cultured bovine granulosa cells, stimulated by ascorbate and catecholamines". Journal of Endocrinology 116, n. 2 (febbraio 1988): 247–58. http://dx.doi.org/10.1677/joe.0.1160247.
Testo completoAbstract (sommario):
ABSTRACT Bovine granulosa cells secrete oxytocin when cultured in a serum-supplemented medium. The time-course of secretion is similar to that in the early corpus luteum in vivo, with a delay of 1 to 2 days followed by a peak and decline over the first 5 days of culture. We have investigated the basis of this time-course in vitro and studied the temporal characteristics of the stimulatory actions of ascorbic acid and adrenaline on this process. Cells cultured on stirred microcarriers showed a similar pattern of secretion of oxytocin to those cultured on conventional flat plates, despite continuing and rapid mitosis. This indicated that the secretion profile in conventional culture was not an artifact related to the cessation of mitosis. Furthermore, secretion of oxytocin and progesterone by cells on microcarriers was stimulated without a corresponding change in mitotic rate, showing that the secretion per cell had been increased. In conventional culture, addition of ascorbic acid to culture media (0·5 mmol/l) increased the secretion of oxytocin (up to 4·5-fold) but only if ascorbic acid was present during the first day of culture. The cells showed a progressive refractoriness to stimulation after 12 h. Since the time-course of secretion was unaltered by treatment, this resulted in a delay of 1 to 2 days before the action of the ascorbate was seen. The secretion of progesterone was similarly affected but with less stimulation and less consistency. In contrast, cells treated with adrenaline (10 μmol/l) secreted more oxytocin on the day of treatment and did so at any time during culture provided that there was sufficient basal secretion of hormone. Adrenaline also failed to alter the time-course of secretion but treated cells showed a persistent response, maintaining enhanced secretion for up to 3 days after the adrenaline had been removed. Ascorbate and adrenaline were highly synergistic in their effects, provided that the ascorbate was present from the start of culture; the response to adrenaline strongly reflected the degree of ascorbate stimulation. We conclude that granulosa cells secrete oxytocin according to an inherent time-schedule and that there is a limited period during which they can respond to ascorbate. Since ascorbate is required for the biosynthesis of oxytocin, this suggests that the availability of ascorbate during corpus luteum formation may determine the amount of oxytocin which can be released subsequently in response to catecholamines. J. Endocr. (1988) 116, 247–258
36
Rudakov, Roman, Liliya Khamitova, Anastasiya Metlyakova e Vyacheslav Milaev. "System of prevention of gynaecological diseases in high-productive cows under in a farm in the Udmurt Republic". BIO Web of Conferences 27 (2020): 00094. http://dx.doi.org/10.1051/bioconf/20202700094.
Testo completoAbstract (sommario):
The purpose of the work is to develop a system for the restoration of the genital organs of cows after calving. We studied the therapeutic efficacy of drugs for the incidence of genital diseases of cows. The studies were conducted based on a complex of cattle of Black Motley breed at the facilities of Rico-Agro LLC in the Uvinsky district, Udmurt Republic. The average milk yield per lactation is 6250 kg. Most animals are susceptible to ovarian disease. The incidence of ovaries hypofunction increases annually. In the study of cows on the 60th day after calving, it was found that the uterus was ready for insemination in 86% of cows. However, the condition of the ovaries allows insemination of only 50% of the cows. The remaining animals needed treatment. The most common pathology was ovarian hypofunction. This is more common in highly productive cows and cows with a low body mass index. Three regimens for treating ovaries have been tested. The most effective Scheme 2 included Surfagon and an emulsion from ASD-2 and Tetravit. In the Scheme 2 group, 6 out of 8 cows were first successfully inseminated. It was established that using Estrofan on the first day after calving, it is possible to reduce the number of persistent corpus luteum.
37
Long, S. T., P. V. Gioi e N. T. Suong. "Some Factors Associated with Ovarian Disorders of Dairy Cattle in Northern Vietnam". Tropical Animal Science Journal 44, n. 2 (giugno 2021): 240–47. http://dx.doi.org/10.5398/tasj.2021.44.2.240.
Testo completoAbstract (sommario):
This research’s objectives were to assess the risk factors associated with ovarian disorders in dairy cattle in Hanoi Capital, Ha Nam Province, Vinh Phuc Province, and Moc Chau District in Son La Province. The ovarian diseases were evaluated by rectal palpation combined with information collected based on the questionnaire and surveys. Records of feeding management and ovarian disorders were comprising of persistent corpus luteum (PCL), cystic ovarian disease (COD), inactive ovary (IO) from 818 females, including heifers and cows from the first to the eighth parities. A multinomial logistic regression procedure in SAS9.0 was applied for data analysis. The results have shown that the changes of region, age classes, housing condition, and body condition scores were associated with the odds of suffering from dairy cattle’s ovarian disorder categories. The cows got the odds of suffering from PCL in the old age or fatter condition, and IO at the younger or angular cows. When cattle were confined in simple houses or laid on rubber bedding, they suffered from IO, but they tended to get the odds of suffering from PCL when the cattle were raised in modern houses or laid on concrete bedding. In conclusion, region, parity, body condition score, housing type, and bedding material affect ovarian disorders in dairy cattle in northern Vietnam.
38
Thatcher, WW, la Sota RL de, EJ Schmitt, TC Diaz, L. Badinga, FA Simmen, CR Staples e M. Drost. "Control and management of ovarian follicles in cattle to optimize fertility". Reproduction, Fertility and Development 8, n. 2 (1996): 203. http://dx.doi.org/10.1071/rd9960203.
Testo completoAbstract (sommario):
Experiments were designed to elucidate the control of ovarian follicle turnover and the impact of follicular dynamics on the subsequent fertility of dairy cattle. An experimental model was established to examine the interrelationships of gene expression for steroid enzymes, the insulin-like growth factor system and inhibin production as associated with follicle selection, dominance and atresia. Follicular dynamics during the postpartum period and the oestrous cycle are shown to be altered markedly by the metabolic demands of lactation. The feeding of ruminally-inert fat stimulated follicular development and improved reproductive performance. The development of persistent follicles during oestrus synchronization causes a reduction in fertility that can be corrected by recruitment and selection of a new ovulatory follicle after the injection of a gonadotrophin-releasing hormone agonist. Present systems of oestrus synchronization need to consider both synchronization of follicular development and corpus luteal regression in order to optimize fertility. With current systems manipulating follicle development, the potential to implement a timed insemination programme to improve reproductive management exists. Ovulation of the first-wave dominant follicle with human chorionic gonadotrophin provides a means to markedly enhance concentrations of plasma progesterone in the luteal phase.
39
Carrasco, R., J. Singh e G. P. Adams. "135 SHORT-TERM OVARIAN EFFECTS OF UNILATERAL OVARIECTOMY IN COWS". Reproduction, Fertility and Development 28, n. 2 (2016): 197. http://dx.doi.org/10.1071/rdv28n2ab135.
Testo completoAbstract (sommario):
Classical studies established that the removal of one of the paired organs produces a compensatory effect on the remaining organ. In the bovine ovary this aspect has not been examined in detail. We took advantage of follicular and luteal profiles from a previous study to retrospectively examine the effects of ovariectomy before and after ovulation on follicular dynamics of the remaining ovary in cattle. To characterise the prevalence and distribution of tyrosine kinase receptor A in the bovine ovary, the original design involved unilateral ovariectomy of cows at different stages of the periovulatory period. For the purposes of the present study, we combined data into 2 groups, a preovulatory group (n = 6 cows) and a post-ovulatory group (n = 5 cows), to provide sufficient data for statistical interpretation. The cows were examined daily by transrectal ultrasonography to determine the ovarian status. For the preovulatory group, a luteolytic dose of prostaglandin was administered when the dominant follicle of the second follicular wave reached ≥10 mm, and the ovary containing the dominant follicle was removed within 48 h. For the post-ovulatory group, ovariectomy was performed on the ovary containing the newly formed corpus luteum between Days 2 to 6 (Day 0 = ovulation). Unilateral ovariectomy was performed by colpotomy under caudal epidural anaesthesia using a chain ecraseur. After ovariectomy, cows were examined daily by ultrasonography from ovariectomy to the completion of an interovulatory interval (period between 2 ovulations). Single-point data were compared between groups by t-test, and binomial data were compared between groups by Fisher’s exact test. Double ovulations were detected in 3/6 ovariectomized in the preovulatory period and 2/5 ovariectomized in the post-ovulatory period. The first ovulation after ovariectomy tended to occur earlier in the preovulatory group than in the post-ovulatory group (P = 0.08), which was attributed primarily to the development of oversized persistent dominant follicles (~20 mm in diameter for ≥7 days in absence of a corpora lutea) in 2 of 5 cows in the post-ovulatory ovariectomy group. The interovulatory interval after ovariectomy was shorter in the post-ovulatory group than in the preovulatory group (14.6 ± 0.3 v. 20.3 ± 0.6 days; P = 0.01). No distinct patterns were detected in follicular and luteal dynamics between the pre- and post-ovulatory ovariectomy groups. The number of follicles ≥3 mm detected by ultrasonography was greater in the post-ovulatory ovariectomy group than in the preovulatory group on Days 6, 7, 8, and 16 of the first interovulatory interval after ovariectomy. In conclusion, results of this retrospective study support the concept that follicular and luteal effects of removal of one ovary are influenced by the timing of ovariectomy relative to ovulation. A prospective study involving a comparison of ovarian dynamics of the same cows before and after unilateral ovariectomy will provide a better understanding of the disruption that take place and the mechanisms controlling it. Research was supported by the Natural Sciences and Engineering Research Council of Canada.
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Linares, Rosa, Xóchitl N. Acuña, Gabriela Rosas, Elizabeth Vieyra, Deyra A. Ramírez, Andrea Chaparro, Julieta A. Espinoza, Roberto Domínguez e Leticia Morales-Ledesma. "Participation of the Cholinergic System in the Development of Polycystic Ovary Syndrome". Molecules 26, n. 18 (10 settembre 2021): 5506. http://dx.doi.org/10.3390/molecules26185506.
Testo completoAbstract (sommario):
In rats with polycystic ovary syndrome (PCOS) induced by injection of estradiol valerate (EV), unilateral or bilateral section of the vagus nerve restores ovulatory function in 75% of animals, suggesting that the vagus nerve participates in the development of PCOS. Since the vagus nerve is a mixed nerve through which mainly cholinergic-type information passes, the objective of the present study was to analyze whether acetylcholine (ACh) is involved in the development of PCOS. Ten-day-old rats were injected with 2.0 mg EV, and at 60 days of age, they were microinjected on the day of diestrus in the bursa of the left or right ovary with 100 or 700 mg/kg of ovarian weight atropine, a blocker of muscarinic receptors, and sacrificed for histopathological examination after the surgery. Animals with PCOS microinjected with 100 mg of atropine showed a lack of ovulation, lower serum concentrations of progesterone and testosterone, and cysts. Histology of the ovaries of animals microinjected with 700 mg of atropine showed corpus luteum and follicles at different stages of development, which was accompanied by a lower concentration of progesterone and testosterone. These results allow us to suggest that in animals with PCOS, ACh, which passes through parasympathetic innervation, is an important component in the persistence and development of the pathophysiology.
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Ruginosu, Elena, Mariana Sofronie, I. Borş, Şt Creangă e L. Dascălu. "Studies on Treatments Results from Cows with Ovarian Disorders in Relation to Year and Season". Cercetari agronomice in Moldova 45, n. 3 (1 settembre 2012): 87–100. http://dx.doi.org/10.2478/v10298-012-0059-9.
Testo completoAbstract (sommario):
Abstract The studies were performed in the dairy farm from Dancu Research and Development Station for Cattle Breeding, Iaşi, Romania, for a period of 5 consecutive years (2007- 2011), an effective annual rolled of 450 cows Bălţată cu Negru Românească (Romanian Black Spotted) breed.The experimental groups were composed of cows with anoestrus in 60 days postpartum interval, diagnosed by rectal examination with various ovarian disorders: persistent corpus luteum - group E1-162 cows and luteal cysts- group E2-138 cows. The treatments according to diagnosis were applied: PGF2α-,500 mcg/cow- group E1 and Gn-RH, (Receptal, 5 ml/cow-group E2). In relation to the year in which treatments were applied some variations in reproduction indices were found. Regarding to average intervals from treatment to first insemination and from treatment to conception respectively, significant differences were not found. Regarding to average conception rates after treatments, significant differences were found: in E1group, conception rate at the first insemination was 30,9% (with annual variations between 15,0% in 2008 and 41,1% in 2009) (p<0,01); per total insemination was 64,42 % (with annual variations between 44,7% - 2011 and 76,9% - 2007) (p<0,001) and pregnancy index was of 2,4 (with annual variations between 1,9 - 2009 and 2,8 - 2008); in E2 group, conception rate to first insemination was 25,96% (with annual variations between 16,66% - 2011 and 40% - 2010) (p<0,01); per total insemination was 77,88% (with annual variation between 52,17% - 2008 and 85,0% - 2010) (p<0,001) and pregnancy index of 2,4 (with annual variations between 2,1 - 2007 and 2,6 - 2008 and 2009). In relation to season in which treatments were applied, we found different variations in conception rates: in group E1, the average conception rates at the first insemination were between 24,24 % (autumn) and 40,7% (summer) (p<0,05) and per total inseminations between 75,0% (spring) and 85,71% (autumn) (p<0,05); in group E2, the average conception rates at the first insemination were between 5,3% (summer) and 48,5% (spring) (p<0,001) and per total inseminations between 68,4% (summer) and 81,8% (spring) (p<0,05). We believe that annual and seasonal variations found in this work are due to some deficiencies of management system in dairy farms, such as the stalls prolonged maintenance and lack of active movement in the cold season, inadequate microclimate of shelters, heat stress and deficiencies in cows feeding , especially those with higher milk production.
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CHAUDHARY, SHAMA, IQRA JANGDA e RUBINA HUSSAIN. "MOLAR ECTOPIC PREGNANCY;". Professional Medical Journal 20, n. 04 (15 agosto 2013): 638–41. http://dx.doi.org/10.29309/tpmj/2013.20.04.1106.
Testo completoAbstract (sommario):
Ectopic molar pregnancy is a rare occurrence. Clinical diagnosis of a molar pregnancy is difficult but histopathology is thegold standard for diagnosis. The management of ectopic molar pregnancies consists of surgically removing the conceptus, follow up &chemotherapy, if required. We are reporting a case report of a 35-year-old married, nulliparous woman, admitted in emergency with a 6-week history of amenorrhea, severe abdominal pain & an episode of fainting at home. Per abdominal examination revealed tendernessover the right iliac fossa, with guarding & rigidity. Diagnosis of ruptured ectopic pregnancy was made.Emergency laparotomy was done.Histopathological examination, showed tubal ectopic pregnancy with partial hydatidiform mole & a separate corpus luteal cyst.She wasfollowed up with serial beta hCG which became normal within 1 month. Although ectopic molar pregnancy is a rare entity but all ectopicpregnancies should be examined histologically to rule out presence of gestational trophoblastic disease to plan follow-up accordingly inorder to avoid persistent gestational trophoblastic disease which has a chance of malignant conversion.The prognosis of ectopic molarpregnancies is the same as for other forms of gestational trophoblastic disease.
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Yoshida, Masahide, Yuki Takayanagi, Azusa Ichino-Yamashita, Kei Sato, Yukihiko Sugimoto, Tadashi Kimura e Katsuhiko Nishimori. "Functional Hierarchy of Uterotonics Required for Successful Parturition in Mice". Endocrinology 160, n. 12 (13 settembre 2019): 2800–2810. http://dx.doi.org/10.1210/en.2019-00499.
Testo completoAbstract (sommario):
Abstract Parturition is an essential process in placental mammals for giving birth to offspring. However, the molecular machineries of parturition are not fully understood. We investigated whether oxytocin plays a crucial role in the progress of parturition in cooperation with the prostaglandin F2α (PGF2α) receptor. We first examined alterations in the expression of uterine contraction-associated genes in uteri of oxytocin receptor–deficient mice (Oxtr−/−) during parturition. We found that induction of cyclooxygenase (COX)-2 and connexin 43 expression was impaired in Oxtr−/−, whereas that of PGF2α receptor expression was not. We next generated mice with double knockout of genes for the oxytocin receptor/oxytocin and PGF2α receptor (Oxtr−/−;Ptgfr−/− and Oxt−/−;Ptgfr−/−) and evaluated their parturition with Oxtr−/−, Oxt−/−, Ptgfr−/−, and wild-type mice. In Oxtr−/−;Ptgfr−/− and Oxt−/−;Ptgfr−/−, pregnancy rates were similar to those of other genotypes. However, normal parturition was not observed in Oxtr−/−;Ptgfr−/− or Oxt−/−;Ptgfr−/− because of persistent progesterone from the corpus luteum, as observed in Ptgfr−/−. We administered RU486, a progesterone antagonist, to Ptgfr−/−, Oxtr−/−;Ptgfr−/−, and Oxt−/−;Ptgfr−/− on gestation day 19. These mice were able to deliver a living first pup and the parturition onset was similar to that in Ptgfr−/−. Meanwhile, unlike Ptgfr−/−, ∼75% of Oxtr−/−;Ptgfr−/− and Oxt−/−;Ptgfr−/− administered RU486 remained in labor at 24 hours after the onset of parturition. All of the pups that experienced prolonged labor died. We thus revealed that the oxytocin receptor is an upstream regulator of COX-2 and connexin 43 in the uterus during parturition and that both oxytocin/oxytocin receptor and PGF2α receptor are major components for successful parturition.
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Sánchez-Criado, José E., Antonio Sánchez, Antonio Ruiz e Francisco Gaytán. "Endocrine and morphological features of cystic ovarian condition in antiprogesterone RU486-treated rats". Acta Endocrinologica 129, n. 3 (settembre 1993): 237–45. http://dx.doi.org/10.1530/acta.0.1290237.
Testo completoAbstract (sommario):
Four-day cyclic Wistar rats (200 g body wt) were injected (sc) with the antiprogestagen RU486 (4 mg RU486/0.2 ml oil) on estrus, metestrus, diestrus and proestrus. Groups of rats (12–15) were decapitated on days 1 (day of expected ovulation), 5, 9, 13, 17 and 21 after the 4 days of RU486 treatment. Oil-injected rats decapitated on proestrus (day 0) and estrus (day 1 ) served as controls. In both controls and RU486-treated rats, the following parameters were noted: ovulation, vaginal smears and luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, testosterone and estradiol-1 7β serum concentrations. Also, pituitary, adrenal, uterus and ovary weight were recorded. RU486 induced ovulation blockade, persistent vaginal cornification, uterine ballooning and increased serum levels of LH, FSH, prolactin, testosterone and estradiol. Furthermore, the LH/FSH and testosterone/estradiol ratios in serum increased. Pituitary and ovary weights also increased. The enlarged ovaries showed follicular cysts undergoing atresia and/or different degrees of luteinization of granulosa cells resembling, in some cases, genuine corpus luteum containing the ovocyte. The small follicles showed extensive atresia and stimulated thecal cells. These effects are reversible and remain in a stationary state for about 9–13 days after RU486 treatment. While the endocrinological alterations found in rats treated with RU486 are similar to those exhibited in polycystic ovarian disease, the morphological alterations found in the ovaries seem to be more closely related to the multicystic ovarian condition. Overall, the results suggest that progesterone deficiency may be of relevance in the initiation of the cystic condition in the rat, and support the concept that a lack of progesterone is conducive to the perpetuation of the cystic state after the cyst follicles first develop.
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Huerta, Ángel Lemus, Junior Joel Araiza Navarro, Araceli Román Pompa, Oyuki Aricet Morales Uscanga, Margarita Eugenia Pérez Chavura e Jorge Arturo Barbabosa Vilchis. "Advanced tubal ectopic pregnancy of 19 weeks gestation: case report and review of the literature". International Journal of Reproduction, Contraception, Obstetrics and Gynecology 7, n. 11 (25 ottobre 2018): 4794. http://dx.doi.org/10.18203/2320-1770.ijrcog20184551.
Testo completoAbstract (sommario):
Ectopic pregnancy is a condition in which the fertilized ovum is impacted anywhere other than the uterine cavity, these sites may be uterine tubes, cervix, ovary and abdomen. Ectopic implantation in the uterine tubes occurs up to 98%. The distribution according to its location is: 78% ampullary, 12% isthmic, 5% fibrous, 2-3% interstitial, 1% ovarian, 1-2% abdominal, and more rare in cervix with 0.5%. Ectopic pregnancy occurs 1.2 to 2% of pregnancies, with an associated mortality of 0.5 deaths per 1000 pregnancies. There are multiple risk factors for an ectopic pregnancy, among the most frequent are: women with pelvic inflammatory disease (salpingitis) conditioned mainly by Chlamydia trachomatis and Neisseria gonorrhea, anatomical abnormalities of the tubes, previous surgery in them (including sterilization), masses extrinsic tumors that compress them, endometriosis, zygote anomalies, endocrinopathies (corpus luteum deficiency in late ovulation), use of intrauterine devices, previous ectopic pregnancy (as a result of surgical treatment or due to persistence of the original risk factor), contraceptive users with gestagens in low doses, assisted reproduction techniques, smokers, secondary adhesions to surgical interventions on the uterus, ovaries, and other pelvic or abdominal organs, exposure of the uterus to diethylstilbestrol, among others. The objective of this case is to describe an advanced tubal ectopic pregnancy. The following case report is about a 24-year-old patient with a pregnancy of 19 weeks of gestation by first-trimester ultrasound and a history of recent laparoscopic cholecystectomy secondary to biliary lithiasis. He is in the first trimester of normo-evolutive and without symptoms. Authors present to the emergency department with a 24-hour abdominal pain syndrome that requires exploratory laparotomy and right salpingo-oophorectomy due to the presence of ruptured tubal ectopic pregnancy with average fetometry of 19 weeks of gestation. The patient is discharged after an adequate clinical evolution.
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Ortegon, H., J. Petrik, J. S. Walton e W. H. Johnson. "238 THE EFFECT OF TRANSVAGINAL FOLLICULAR ASPIRATION AND THE ROLE OF PROGESTERONE IN FOLLICULAR CYSTS OF DAIRY CATTLE". Reproduction, Fertility and Development 18, n. 2 (2006): 227. http://dx.doi.org/10.1071/rdv18n2ab238.
Testo completoAbstract (sommario):
Ovarian follicular cyst (CYS) is a common condition affecting 5-25% of postpartum dairy cows, increasing the number of days open, calving intervals, cow costs, and culling rates, and with an effect on fertility rates. Current hormonal treatment has variable responses. Debate exists regarding progesterone (P4) influence on CYS formation and the effect of the aspirated CYS in resumption of cyclicity. The objectives of this descriptive study were to investigate the effect of ultrasound-guided transvaginal follicular aspiration on the resumption of follicular dynamics, to determine the fate of the aspirated CYS, and to find the P4 relationship. Resumption of ovarian cyclicity was determined by ovulation, formation of a corpus luteum (CL), and a P4 rise over 3.2 nmol/L. Ten (10) postpartum (35-60 days in milk (DIM)) lactating Holstein cows with CYS were selected. They were monitored every other day by rectal palpation, ultrasonography, and P4 concentration for 30 days post-aspiration. Change in size of the aspirated CYS and emergence of a new follicular wave were recorded and images were saved electronically. Results were analyzed using Pearson correlations, linear regression, and one-way ANOVA. Of these cows, 5/10, 3/10, and 1/10 resumed cyclicity after the 1st, 2nd, and 3rd aspirations, respectively. Two (2/10) cows did not resume cyclicity during the observation period. Size of aspirated CYS was 34.6 � 0.2 mm (mean � SEM). Seven (7/10) cows had intermediate (0.98 � 0.3 nmol/L) and 3/10 cows had high (8.6 � 3.6 nmol/L) P4 concentration at aspiration. Mean times from aspiration to emergence of a new follicle, to ovulation, and to detection of a new CL were 3.6 � 1.4, 10.5 � 2.0, and 15.2 � 3.0 days, respectively. New cysts grew in 4/10 cows after the first aspiration and one aspirated CYS refilled twice. Dominant follicles present at first aspiration (DFPF) had the tendency to undergo cyst turnover (4/9) or to ovulate (2/9) at a larger size (25.7 � 3.2 mm). The CYS size was correlated (r = 0.58; P = 0.05) with circulating P4 concentration. These data, together with a significant (P = 0.05) drop in P4 concentration following aspiration (from 3.26 � 1.5 to 2.16 � 0.1 nmol/L), suggest that the CYS may be the source of P4. Persistence of the aspirated cyst was associated (r = 0.87) with increased days to ovulation. The significant association (r = 0.96; P = 0.01) between P4 at ovulation (2.29 � 0.6 nmol/L) and the size of the ovulatory follicle (18.5 � 2.0 mm) may explain the tendency of existing follicles to persist (cyst turnover) or to ovulate at a larger size. In summary, follicular aspiration was successful in inducing resumption of cyclicity and shortening days to ovulation in half of the cases with one aspiration. Persistence of the aspirated CYS increased days to ovulation. P4 may have a follicular origin and an influence on the size of the cyst and the ovulatory follicle. DFPF tend to undergo cyst turnover or to ovulate at a larger size. However, resumption of normal cyclicity may also be influenced by other factors, such as stress, disease, and energy balance.
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Bottino, M. P., L. A. C. L. DaSilva, L. M. S. Simoes, G. Santos, I. Y. H. Martinez, P. A. M. Barros, J. C. DeSouza, P. S. Baruzelli e J. N. S. Sales. "13 Pre-synchronization by Induction of a Dominant Follicle Using a Progesterone Device in a GnRH-Based-Ovulation Synchronization Protocol in Lactating Dairy Cows". Reproduction, Fertility and Development 30, n. 1 (2018): 146. http://dx.doi.org/10.1071/rdv30n1ab13.
Testo completoAbstract (sommario):
The objective was to compare a pre-synchronization protocol by induction of a dominant follicle using a progesterone intravaginal device before an Ovsynch protocol (Presynch) with Double-Ovsynch in lactating dairy cows. Lactating Bos indicus × Bos taurus crossbred cows (n = 440) were randomly allocated to 1 of 2 treatments (all IM injections): (1) Double-Ov (n = 228): GnRH (Day –17), prostaglandin F2α (PGF2α) 7 days later (Day –10) and gonadotropin-releasing hormone (GnRH) 3 days later (Day –7) followed by an Ovsynch protocol 7 days later (GnRH on Day 0, PGF2α on Day 7, GnRH on Day 9); (2) Presynch (n = 212): insertion of a sustained release progesterone intravaginal device (Day –10), 10 days later (Day 0), an Ovsynch protocol was initiated with progesterone device withdrawal on Day 7. All cows were artificially inseminated 15 to 20 h after the second GnRH injection of the Ovsynch protocol and were pregnancy checked by ultrasonography 30 and 60 days later. On a subsample (n = 102), ultrasonography was performed on Days 0, 7, 9, and 24 of the experimental period. On another subsample (n = 42), blood samples for progesterone analysis were taken on Days 0, 7, and 24. There were no differences between pre-synchronization methods on synchronization parameters [presence of a follicle >12 mm on D0, Double-Ov 94.2% (49/52) and Presynch 92.0% (46/50); P = 0.66], follicular diameter on the 1st GnRH (Double-Ov 17.2 ± 0.7 mm and Presynch 18.6 ± 0.9 mm; P = 0.28), ovulation rate to the 1st GnRH [Double-Ov 86.3% (44/51) and Presynch 81.2% (39/48); P = 0.50], synchronization rate [Double-Ov 84.6% (44/52) and Presynch 86.0% (43/50); P = 0.84], follicular diameter on the 2nd GnRH (Double-Ov 17.5 ± 0.6 mm and Presynch 18.0 ± 0.5 mm; P = 0.48), ovulation rate to the 2nd GnRH [Double-Ov 90.9% (40/44) and Presynch 86.0% (37/43); P = 0.48] and CL diameter on Day 24 (Double-Ov 27.9 ± 0.7 mm and Presynch 29.4 ± 0.9 mm; P = 0.19). Corpus luteum presence on Day 0 was different (P = 0.03) between treatments [Double-Ov 57.7% (30/52) and Presynch 36.0% (18/50)]. Moreover, there was no difference (P = 0.85) between pregnancy rates on Day 30 [Double-Ov 39.0% (89/228) and Presynch 40.1% (85/212)] or Day 60 after AI [Double-Ov 34.8% (79/227) and Presynch 38.7% (82/212); P = 0.41] and gestational loss between 30 and 60 days after AI [Double-Ov 7.9% (7/88) and Presynch 3.5% (3/85); P = 0.13]. Proportion of cows with P4 <1 ng mL−1 on Day 0 was similar between treatments [Double-Ov 13.6% (3/22) v. Presynch 5.0% (1/20); P = 0.37]. Likewise, the proportion of cows with P4 >1 ng mL−1 on Day 7 [Double-Ov 77.3% (17/22) v. Presynch 95.0% (19/20); P = 0.14] and P4 concentration on Day 24 (Double-Ov 4.7 ± 0.6 v. P4-Ov 5.9 ± 0.9; P = 0.84) were similar between treatments. In conclusion, pre-synchronization by induction of follicular persistence using a sustained-release progesterone device before Ovsynch yielded similar results to the Double-Ovsynch protocol on follicular development and regression patterns and on the fertility of lactating dairy cows.
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Pemayun, Tjok Gde Oka, Imam Mustofa, Laba Mahaputra, Herry Agoes Hermadi, Ngakan Made Rai Wijaya, Sri Mulyati, Suzanita Utama, Tjuk Imam Restiadi e Rimayanti Rimayanti. "Fertility restoration of racing mare with persistent corpus luteum". Veterinary World, 8 settembre 2021, 2356–61. http://dx.doi.org/10.14202/vetworld.2021.2356-2361.
Testo completoAbstract (sommario):
Background and Aim: Persistent corpus luteum (PCL) causes anestrus in mares. This study aimed to determine the effect of intrauterine prostaglandin F2α (PGF2α) treatment on PCL of racing mares to restore fertility. Materials and Methods: Twelve racing mares suspected with PCL were diagnosed using transrectal palpation and confirmed by serum progesterone (P4) concentration measurement. PGF2α was infused intrauterine, followed by serum collection at 24, 48, and 72 h after. Estrous symptoms were monitored, and mating was conducted on day 3 of estrus with an earlier injection of 8.4 μg gonadotropin-releasing hormone twice a day. Transrectal palpation was performed on days 21-30 to observe the corpus luteum. Pregnancy diagnosis was performed rectally on 40-45 days post-mating and confirmed using Doppler ultrasound scanning. Results: Eleven of the 12 mares had PCL. There was a dramatic reduction in the P4 concentration following PGF2α treatment of mares with PCL. All mares exhibited estrus 2.6±0.55 days post-treatment with a P4 concentration of 0.12±0.12 ng/mL. Rectal palpation and P4 concentration on 21-30 days after estrous onset showed that all mares were ovulating. The evaluation of P4 concentration on days 40-45 post-mating showed that all mares were still in the luteal phase. However, the pregnancy rate was only 54.5% based on rectal palpation and Doppler ultrasound scanning. Conclusion: Treatment of PCL in racing mares with an intrauterine infusion of PGF2α restored the estrous cycle and induced ovulation and pregnancy.
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Ullmann, SL, AJ Russell, JI Mason e L. Selwood. "Species differences in the ovarian distribution of 3beta-hydroxysteroid dehydrogenase/delta5-->4 isomerase (3beta-HSD) in two marsupials: the brushtail possum Trichosurus vulpecula and the grey, short-tailed opossum Monodelphis domestica". Reproduction, 1 gennaio 2003, 65–73. http://dx.doi.org/10.1530/rep.0.1250065.
Testo completoAbstract (sommario):
The ovarian distribution of the steroidogenic enzyme 3beta-hydroxysteroid dehydrogenase/delta(5-->4) isomerase (3beta-HSD) was investigated by immunocytochemistry in two marsupial species throughout the reproductive cycle, using a rabbit polyclonal antibody raised against human placental 3beta-HSD. In the polyoestrous and polyovular South American opossum Monodelphis domestica, immunostaining was positive for 3beta-HSD in the adrenal cortex, the ovarian interstitial tissue, the corpus luteum and the granulosa cells of antral and atretic follicles. The theca interna was weakly positive for 3beta-HSD, but only in late preantral to early antral stages of follicular development. The adrenal medulla and smaller preantral follicles were completely negative for 3beta-HSD. In contrast, in the polyoestrous and monovular Australian brushtail possum Trichosurus vulpecula, immunostaining showed a strong positive reaction for 3beta-HSD in the theca, whereas the granulosa layer remained predominantly negative for 3beta-HSD except in the largest follicles. The atretic follicles were completely negative for 3beta-HSD. The ovaries of pregnant animals contained grossly enlarged, persistent, antral follicles, which reacted positively for 3beta-HSD. The function of these follicles in T. vulpecula and the 3beta-HSD-positive atretic follicles in M. domestica has not been determined. The differences between the two marsupials represent species variations. The situation in M. domestica does not represent a marsupial-eutherian dichotomy as previously conjectured.