Endometrial Edema Research Articles

Is platelet-rich plasma effective in treating uterine inflammation in jennies inseminated with cryopreserved donkey semen?

Despite frozen donkey semen demonstrating high quality after thawing and achieving suitable pregnancy rates in mares, it yields unsatisfactory results in jennies, likely due to a stronger uterine inflammatory response. This study assessed the effects of platelet-rich plasma (PRP) on uterine inflammation and pregnancy rates in jennies inseminated with frozen donkey semen. Estrous cycles from 11 jennies were assigned to three groups: Control (CTR, n=22) with no treatment; Single PRP infusion (S-PRP, n=22) administered 30 hours after ovulation induction, prior to artificial insemination (AI); and Double PRP infusion (D-PRP, n=21) with the first infusion at 30 hours after ovulation induction and the second 4 hours after AI. Insemination was performed with frozen donkey semen (1 billion sperm) deposited deeply in the uterine horn immediately after ovulation. Endometrial edema, intrauterine fluid (IUF), uterine vascularization, and endometrial cytology were evaluated pre-AI (TCt) and post-AI (6, 24, and 48 hours). Uterine biopsies were taken at T48 for histopathological and collagen evaluation. Peripheral blood samples were collected on D5 for serum progesterone measurement, and pregnancy was evaluated via ultrasonography on D14. Data were analyzed using GLMMs, ANOVA, Friedman, and Kruskal-Wallis tests in SAS and GraphPad Prism, with significance set at p<0.05. The S-PRP group showed less IUF accumulation than the CTR group at T6. Other parameters showed no significant differences among the groups. Cytology revealed a high percentage of inflammatory cells at T6 in all groups, which decreased in subsequent evaluations. In the CTR group, neutrophil percentages were similar to TCt at T24, while treated groups reached this similarity only by T48. Eosinophil percentages increased over time only in the treated groups. Pregnancy rates showed no differences among the groups (CTR: 0%, S-PRP: 0%, D-PRP: 10%). Results indicate that PRP treatments were ineffective in modulating uterine inflammation and did not enhance pregnancy rates in jennies inseminated with frozen donkey semen.

Effect of intrafollicular administration of PGE2 or PGF2α in early estrus on ovulation, hemorrhagic anovulatory follicles formation, progesterone secretion and pregnancy outcome in the mare

This experiment was performed to evaluate whether intrafollicular treatment of PGE2 or PGF2α administered in early estrus would induce normal ovulation, progesterone production (Experiment 1) and pregnancy (Experiment 2). In Experiment 1, mares in estrus after 2 days of endometrial edema were injected in all largest dominant follicles (28–35 mm in diameter) with 0.5 mL of sterile water containing 500 μg PGE2 (n = 6), 125 μg PGF2α (n = 6) or placebo (n = 7) (Hour 0). Ultrasound examinations were performed daily, until ovulation or anovulation was detected, and daily blood samples were taken for 8 days. In Experiment 2, mares with a dominant follicle ≥35 mm after at least three days of slight-to-moderate endometrial edema, were injected with 500 μg PGE2 diluted in 0.5 mL of sterile water for injection in the follicle (PGE2 group; n = 9 mares and 11 dominant follicles). No puncture was performed in the control group (n = 9 mares and 11 dominant follicles). Mares from both groups were inseminated. In Experiment 1, all mares (6/6) in the PGE2 group ovulated within 24 h of treatment. The mean interval from intrafollicular injection to ovulation was shorter (P < 0.001) in PGE2 mares (24 ± 0 h) than in control mares (77 ± 9 h). Mares from the PGF2α group developed hemorrhagic anovulatory follicles (HAF) more often (7/7) than control mares (2/7); P < 0.05). The progesterone concentration in mares from the PGF2α group was lower (P < 0.004) than control mares in the early post-ovulatory period. The first significant increase in post-ovulatory progesterone concentration occurred earlier (P < 0.05) in mares from the control group than in mares from the PGF2α and PGE2 groups. In Experiment 2, more mares from the control group (7/9, 78 %) became pregnant than from the PGE2 group (2/9, 22 %) (P = 0.015). In conclusion, PGE2 alone induced follicle collapse in all treated mares within 24 h of administrations, while PGF2α blocked ovulation and induced formation of HAFs. However, the post-ovulatory rise in progesterone production was delayed and the fertility reduced in mares with ovulation induced by PGE2 compared to control mares.

Chronic endometritis - a constantly discussed issue in infertile women.

A review of current knowledge on the pathophysiology, diagnostic and treatment options for chronic endometritis in infertile women. One of the major causes of failed in vitro fertilization (IVF) is undiagnosed intrauterine pathologies, including chronic inflammation of the uterine mucosa - chronic endometritis. However, some authors relativize the negative impact of chronic endometritis on reproductive outcomes. The etiopathogenesis of chronic endometritis is due to qualitative and quantitative changes in the endometrial microbiome with abnormal multiplication of microorganisms naturally occurring in the uterine cavity or vagina. There is no uniform consensus on the most common pathogen causing chronic endometritis. It is characterized by infiltration of plasma cells into the endometrial stroma outside the menstrual cycle, accompanied by hyperaemia and endometrial oedema. Clinical symptoms are very mild or absent. The diagnosis of chronic endometritis is often difficult because there is no specific clinical or laboratory diagnostic method. The following investigative options are commonly used for the diagnosis of chronic endometritis: diagnostic hysteroscopy, histopathological examination of the endometrium including CD 138 immunohistochemistry and culture from the uterine cavity. However, standardised international hysteroscopic and histopathological criteria for accurate diagnosis of chronic endometritis are still lacking. Empirically administered antibiotic therapy improves the success rate of pregnancy and delivery of a viable foetus in infertile patients with proven chronic endometritis. In addition to reviewing the current knowledge of chronic endometritis, this article discusses the importance of hysteroscopy in the diagnostic process. Chronic endometritis is often a clinically silent disease with negative impact on reproduction in infertile women. Although there are still many unresolved issues, the introduction of hysteroscopy into the diagnostic process is important for clinical practice; however, hysteroscopy even in combination with histological examination of the endometrium, often does not allow an unequivocal diagnosis of chronic endometritis. Further prospective randomised studies in a selected group of women with proven chronic endometritis and repeated failure to implant proven euploid embryos should refine this knowledge.

Mechanisms of acupuncture for primary dysmenorrhea based on PI3K/Akt/mTOR signaling pathway in rats.

To observe the effect of electroacupuncture(EA) on phosphatidylinositol-3-kinases(PI3K)/protein kinase B(Akt)/mammalian target of rapamycin(mTOR) signaling pathway of uterus tissue in rats with primary dysmenorrhea(PDM), so as to investigate its mechanisms underlying improvement of PDM. Thirty healthy non-pregnant female SD rats were randomly divided into blank, model and EA groups, with 10 rats in each group. The PDM model was established by subcutaneous injection of estradiol diphenhydrate combined with intraperitoneal injection of oxytocin. For rats of the EA group, EA(50 Hz, a tolerable current intensity) was applied to "Guanyuan"(CV4) and bilateral "Sanyinjiao"(SP6) for 20 min, once a day for 10 consecutive days. The number of writhing, wri-thing score, and writhing latency were observed. The uterine histopathological changes were observed by H.E. staining, and the ultrastructural changes of uterine tissue cells in each group were observed by transmission electron microscopy. The contents of prostaglandin E2(PGE2), prostaglandin F2α(PGF2α) and ratios of PGF2α/PGE2 in the serum and uterine tissue were detected by ELISA. The relative expression levels of PI3K, Akt and mTOR and their phosphorylation proteins in the uterine tissue were detected by Western blot and the ratios were calculated. Compared with the blank group, the number and score of writhing, latency of writhing, pathological injury score, contents of PGF2α and ratios of PGF2α/PGE2 in the serum and uterine tissue, and the levels of p-PI3K/PI3K, p-Akt/Akt and p-mTOR/mTOR in the uterine tissue were significantly increased in the model group(P<0.01, P<0.05), while contents of PGE2 in the serum and uterine tissue were reduced(P<0.05). In comparison with the model group, the number of writhing and writhing score, pathological injury score, contents of PGF2α and ratios of PGF2α/PGE2 in both the serum and uterine tissue, the levels of p-PI3K/PI3K, p-Akt/Akt and p-mTOR/mTOR were obviously decreased(P<0.05, P<0.01), whereas the writhing latency was considerably prolonged in the EA group(P<0.01), with elevated contents of PGE2 in the serum and uterine tissue(P<0.05). H.E. staining showed slight dilation of uterine glandular cavity, and severe endometrial edema with extensive cell shedding and a large number of vacuole-like degeneration, apoptosis, pyknosis or fragmentation or disappearance of the nucleus, and neutrophil infiltration in the model group, which were relatively milder in the EA group. Ultrastructural results showed irregular fibroblasts of uterine tissue cells, obvious cytoplasmic edema, reduction in cytoplasmic electron density, seriously irregular nuclei, severe edema of mitochondria with dissolved matrix, fracture and disappearance of mitochondrial crests and vacuolation, and moderate dilation of rough endoplasmic reticulum in the model group, which were milder in the EA group. EA can improve pain and uterine inflammatory response in PDM rats, which may be associated with its functions in reducing uterine PGF2α and down-regulating PI3K/Akt/mTOR signaling.

Plasma estradiol profile after administration of different types of estradiol esters in acyclic mares.

Although the use of different estradiol esters has been extensively studied in hormonal protocols in cows, such information is lacking in mares. The present study aimed to assess the effects of treatment with the same doses and administration frequency of estradiol cypionate, estradiol benzoate and 17β estradiol on plasma estradiol (E2) concentrations of acyclic mares and correlate the E2 profile to the endometrial edema score. Sixteen treatments were performed in 14 mares randomly divided into three groups: EB (n=5), EC (n=5) and 17β (n=6), receiving 10mg on day 0 (D0), 6mg on D1 and 4mg on D2 of estradiol benzoate, estradiol cypionate, and estradiol 17β, respectively. Blood samples, rectal palpations and ultrasound evaluations were performed once daily, starting before the first estradiol treatment (D0) until edema disappearance or D8. Moderate to high edema was observed in all groups 24h after the first estradiol administration. Edema persisted above score 2 until D7, D5 and D4 in groups EC, EB and 17β, respectively. Higher edema was found on D2 in EB group compared to 17β, on D6 and D7 in EC compared to 17β, and on D8 in EC compared to EB (p≤0.05). Maximum E2 concentrations were detected on D1 in groups: EB, showing a sharp decrease from D2 to D3 (p<0.0001); and 17β, where no differences were observed between treatment days (p≥0.05). In the EC group, maximum concentrations were observed on D2, which remained high from D2 to D4 compared to the other days (p<0.0001). Plasma concentration of E2 was higher in EB than the other groups on D0 and D1, and EB>EC>17β on D2. Plasma E2 concentrations and edema score were positively correlated, being moderate in groups EB and EC and weak in the 17β group. In conclusion, the most pronounced plasma E2 concentration was observed in EB group 24h after the administration of the first dose. Estradiol concentrations peaked 48h after EC administration, while a distinct peak was not observed in a 24h interval evaluation in the 17β group. Moreover, high edema does not necessarily reflect on high E2 concentrations in acyclic mares.

Plasma estradiol profile after administration of different types of estradiol esters in acyclic mares.

Although the use of different estradiol esters has been studied extensively in hormonal protocols in cows, such information is lacking in mares. The present study aimed to assess the effects of treatment with the same doses and administration frequency of estradiol cypionate (EC), estradiol benzoate (EB) and 17β estradiol (17β) on plasma estradiol (E2) concentrations of acyclic mares and correlate the E2 profile to the endometrial edema score. Sixteen treatments were performed in 14 mares randomly divided into three groups: EB (n=5), EC (n=5) and 17β (n=6), receiving 10mg on day 0 (D0), 6mg on D1 and 4mg on D2 of estradiol benzoate (Sincrodiol®, Ouro Fino, Brazil), estradiol cypionate (E.C.P®, Zoetis, Brazil), and estradiol 17β (17βeta®, Botupharma, Brazil), respectively. Blood samples, rectal palpations and ultrasound evaluations were performed once daily, starting before the first estradiol treatment (D0) until edema disappearance or D8. Plasma E2 was quantified by radioimmunoassay. Endometrial edema was scored as: 0= lack of edema, 1=mild, 2=moderate, 3=high and 4=exaggerated. Mean estradiol plasma concentrations were analyzed by general linear model of variance with repeated measures. Median edema scores were compared by Kruskal Wallis followed by Mann Whitney tests while Spearman's correlation test was used to correlate E2 concentrations and edema score. Moderate to high edema was observed in all groups 24h after the first estradioladministration. Edema persisted above score 2 until D7, D5 and D4 in groups EC, EB and 17β, respectively. Higher edema was found on D2 in group EB compared to 17β, on D6 and D7 in group EC compared to 17β, and on D8 in group EC compared to EB (p≤0.05). Maximum E2 concentrations were detected on D1 in groups: EB (190±83.3 pg/mL), showing a sharp decrease from D2 to D3 (p<0.0001); and 17β (44.99±15.0 pg/mL), where no differences were observed between treatment days (p≥0.05). In the EC group, maximum concentrations were observed on D2 (81±43.8 pg/mL), which remained high from D2 to D4 compared to the other days (p<0.0001). Plasma concentration of E2 was higher in group EB than the other groups on D0 and D1, and EB>EC>17β on D2. Plasma E2 concentrations and edema scores were positively correlated, being moderate in groups EB and EC (EB: r=0.47; EC: r=0.45, p<0.01) and weak in the 17β group (r=0.39, p<0.0001). In conclusion, the most pronounced plasma E2 concentration was observed in group EB 24h after the administration of the first dose. Estradiol concentrations peaked 48h after EC administration, while a distinct peak was not observed in a 24h interval evaluation in the 17β group. Moreover, high edema does not necessarily reflect on high E2 concentrations in acyclic mares.

Mitigation of post breeding endometritis in mares treated with platelet rich plasma

Persistent breeding-induced endometritis (PBIE) is one of the major causes of infertility in mares, characterized by a lingering inflammatory response in the uterus, which leads to accumulation of uterine fluid and polymorphonuclear cells (PMN), harming the reproductive efficiency of the animal. The aim of this study was to determine if the presence and volume of intrauterine fluid and the percent of endometrial neutrophils decreased after intrauterine application of blood platelet-rich plasma (PRP) in mares with post-mating endometritis. Healthy estrous crossbreed mares (n = 9) aged between 6 to 12 years, with optimal body condition and under the same nutritional management, had two cycles randomly assigned to a crossover trial. Each received either intrauterine infusions of lactate ringer solution (LRS) or autologous PRP 4h after artificial insemination (AI) with fresh semen of low sperm quality from the same stallion. All the animals went through all the treatments. A total of 100 mL of citrated whole blood was collected for PRP production and was centrifuged at 2315g for 15 minutes then 579g for 10 minutes. The presence of intrauterine fluid (IUF) was analyzed by ultrasonographic examination and the percentage of endometrial neutrophils was determined through endometrial cytology, both before insemination (in the presence ofa preovulatory follicle ≥35mm and endometrial edema) and 24h after treatment application. Statistical analysis was performed by a Mixed model (SAS, 2023) for repeated measures with treatment and time as between subject factors. The presence of intrauterine fluid had an effect of time (p ≤ 0.049), where fluid size was smaller before AI than 24h after treatment; however, there was no treatment effect (p ≥ 0.264) over intrauterine fluid. The percentage of endometrial neutrophils had an effect of time (p ≤0.001), less inflammatory cells were found before AI than 24 hours after treatment; there was an effect of treatment (p ≤0.001) as well, where PRP decreased the number of endometrial polymorphonuclear cells compared to the control group infused with LRS. The increase in intrauterine fluid with time suggests that semen itself increases blood perfusion that generates intrauterine fluid accumulation. After induction of physiological endometritis, endometrial polymorphonuclear cell numbers were reduced successfully with PRP treatment. PRP is rich in peptides and signaling proteins that suppress the expression of proinflammatory cytokines such as IL-1 and TNF, inhibits polymorphonuclear neutrophil migration, and thus regulates intrauterine inflammation through decreased endometrial COX-2 expression.

Confocal laser endomicroscopic imaging of equine endometrium: evaluating image quality

A heathy uterus is a key piece of the fertility jigsaw and assessment of the endometrium is an essential component of the breeding soundness examination in mares. The current gold standard for evaluating uterine health is histopathological assessment of an endometrial biopsy. The Kenney-Doig (KD) grading scale is most used and scores both fibrotic and inflammatory changes present within the endometrium. The KD grade provides a prognostic indicator of the probability a mare can carry a pregnancy to full-term. Inconsistencies may arise when a single blinded biopsy is used, especially when uterine pathologic changes don't have a widespread distribution pattern. Confocal laser endomicroscopy (CLE) is a novel imaging modality that enables real-time in-vivo imaging of the endometrium. Multiple subcellular endometrial images (“virtual biopsies”) can be captured in quick succession in multiple locations within the uterine lumen noninvasively. Image depth in the z-axis can be controlled (0-100µm). Image quality was noted to be variable between mares in a previous pilot study (Gallacher.et.al. Journal of Equine Veterinary Science. 2018;66:106). The objective was to determine if physiological endometrial oedema present during oestrus has a negative effect on image quality. Twenty-four mares were examined with CLE (ViewnVivo, Optiscan, Australia) on two separate occasions, once during oestrus and once in dioestrus. A total of 4294 CLE images were captured, witha mean of 89.5 images saved per exam. A 4-point grading scale (1=poor and 4=excellent) was developed for quality assessment. A subset of ∼10 representative images from each of the 48 examinations were selected. Four examiners were blinded to the phase of the oestrous cycle and graded the images using the quality criteria assigned to the 4-point grading scale. An intraclass correlation (ICC) was estimated to determine reliability between the 4 scorers. The ICC coefficient was estimated using the irr package in R. Moderate agreement (ICCC(C,4) = 0.69) between scorers was observed while using the two-way random effect models and average rater where p<0.001. Quality data were analysed using a mixed model in asreml-R. The fixed factors included in the model were depth (1-luminal epithelium, 2-subluminal), cycle (oestrus and dioestrus) with brightness included as a covariate. Scorer and horse were included as random terms. There was a difference (p<0.001) between depth 1 and 2 (2.51 vs 2.71 respectively), and cycle (p<0.001) dioestrus = 2.71 oestrus = 2.51. The brightness of the image was also related to quality score (p<0.001) where a 100unit increase in brightness was associated with a reduction in quality score of ∼0.3. Image quality appears to be influenced by the phase of the oestrous cycle and this may guide the clinician to perform CLE examination during dioestrus.

HCG versus histrelin acetate: ovulation inducing agents in mares (Equus caballus) in a commercial breeding program in Uruguay

Hormonal control of ovulation timing is an effective tool to optimize reproductive management and reduce costs in equine breeding programs. Few studies have evaluated the efficacy of GnRH analog histrelin as an ovulation inducer agent. This study aimed to compare the efficacy of human chorionic gonadotrophin (hCG) and histrelin as ovulation inducers in young, adult, and old mares during spring and summer. Reproductive records of 321 estrous cycles of 125 mares, mean age 9.8±0.37 years, range 1.5–24 years, between 360-600 kg body weight, and body condition ≥3 (1/5), were evaluated during spring (151 cycles) and summer (170 cycles). Mares were kept in the field and fed alfalfa hay, balanced concentrate feed and ad-libitum water. The ovaries, uterus, and cervix underwent transrectal examination and ultrasonography daily. When only one dominant follicle of 35 mm and endometrial edema compatible with estrus were reached, ovulation was induced. Each cycle was monitored every two to six hours until ovulation, 24h after induction. Cycles were randomly allotted in two groups; G1 (n=106 cycles): 1500 IU hCG (IV); G2 (n=215 cycles): 250 μg histrelin acetate (IM). A total of 119 cycles were from young (<8 years), 93 from adults (8-15 years), and 109 from old mares (>15 years). Cycles of mares ovulating within 24-48hafter treatment were considered to have responded to the inducer, and those ovulating before 24h and after 48h were excluded from the experiment. Inducer agents, season (spring or summer), and mare age were independent factors, and ovulation between 24-48h was considered the dependent factor. Data were analyzed through Fisher's exact test. The significance level was defined as P<0.05. From the 321 induced cycles, 254 (79.1%) ovulated within 24-48h, 20 (6.2%) before 24h, and 47 (14.6%) after 48h. There were no differences (P=0.2414) in the average response time between G1 (37.2h±3,5) and G2 (39.3h±4,5). The ovulatory response between G1 and G2 did not differ in spring (84.1% versus 90.7%, P=0.2627) and summer (79.2% versus 85.4%, P=0.3534). Independent of the inducer, the season did not influence the ovulation response in the different mare ages (spring P=0.1489; summer P=0.2992). No differences (P=0.896) were found between drugs in young and adult mares. However, old mares had a higher percentage of ovulatory response in spring and summer to histrelin (n=76) than to hCG (n=24) (89.5% versus 45.8%, P<0.0001). In conclusion, histrelin is more effective and accurate in inducing ovulation in old mares (>15 years) than hCG throughout the breeding season.

Influence of hormonal induction of estrus and/or ovulation on embryo transfer success

The recipient mare is one of the most important elements in an equine embryo transfer program. Mare selection at the time of transfer is based on a number of established criteria such as uterine and cervical tone, absence of endometrial oedema after ovulation and the presence and morphology of the corpus luteum. However, recent studies suggest that other factors, such as estrus duration, have a favorable influence on pregnancy rates. The aim of the study was to determine if the pregnancy rate in recipient mares was influenced by estrous length, induction of estrus with prostaglandin F2alpha and/or induction of ovulation with hCG. Retrospective data from a commercial embryo transfer program in Northern Germany, was analyzed. A total of 1051 embryos were transferred into 880 recipient mares (2-24 years of age) during 2021. Recipient mares were evaluated ultrasonographically daily, from first signs of estrus until ovulation was detected. For the analysis of estrus length, mares were classified according to the number of days that edema was detected ultrasonographically into the following groups: short (1-3 days), medium (4-6 days) and long (7-9 days) estrus. Estrus was induced in 852 (81.06%) and ovulation was induced in 676 (64.31%) cycles. Overall pregnancy rate at day15 post-ovulation was 76.21% (801/1051). Spontaneous estrus had a lower pregnancy rate (70.85%) compared to estrus induced by prostaglandins (77.46%) (p=0.052). Nonetheless, there were no significant differences in embryo transfer success between spontaneous (79.2%) and hCG-induced (74.55%) ovulation (p=0.096). The duration of estrus had no influence on pregnancy rates when evaluating the 1051 embryo transfers. However, when evaluating each estrus length group individually, in the medium and long estrus groups there was a significant effect of ovulation induction on pregnancy rates (p=0.007, p=0.042 medium and long estrus, respectively), suggesting that hCG-induction reduced the success rate vs spontaneous ovulations (71.99% vs 84.05%) in medium length estrus, while increasing pregnancy rate in the long length group (80.85% vs 60.71%). These data suggest that the importance of estrus length on successful embryo transfer rate may be associated with factors such as estrogen exposure and ovulation. In long estrus cycles, ovulation induction may be beneficial in preventing lack of ovulation or estrogen overstimulation. However, a minimum duration of estrogen exposure is necessary to optimize gestation rates. Further studies are needed to evaluate the possible causes of these effects.

The Effect of Treatment with Oestradiol Benzoate on Oestrus Expression and Endometrial Oedema in Anovulatory and Cyclic Mares.

Oestrogens treatment is often used to induce oestrus behaviour in anoestrous mares to aid in the collection of stallion semen and as recipient mares to receive embryos when combined with progesterone. However, there are no studies to describe the effect of dose and individual mare on the intensity and duration of the response, in both anoestrous and cyclic mares. In Experiment 1, 13 anoestrous mares were treated with one of five doses of oestradiol benzoate (OB) (1, 1.5, 2, 3 and 4 mg) per mare in five consecutive treatment periods (n = 65), to determine the response in terms of endometrial oedema and oestrous behaviour. Experiment 2 and 3 used 3 mg of OB in cyclic mares to confirm or deny the presence of an active corpus luteum (CL). There was a dose rate of OB and individual mare effect (p < 0.05) on the intensity and persistence of endometrial oedema and oestrous behaviour. A total of 2 mg OB was enough to induce endometrial oedema and oestrous behaviour within 48 h in most mares. Mares with an active CL did not show endometrial oedema following treatment of 3 mg OB.

Structural and Functional Dynamics of the Ovary and Uterus during the Estrous Cycle in Donkeys in the Eastern Caribbean.

Eight non-bred, non-pregnant, regularly cycling Caribbean jennies were examined daily via transrectal ultrasound to define the ovarian and uterine dynamics during four consecutive estrous cycles. Blood samples were collected every other day for progesterone analysis. The mean (±SD) overall inter-ovulatory interval across all donkeys and cycles was 22.93 ± 1.99 days. The maximum follicular diameter was 34.6 ± 2.9 mm. A two-wave pattern was evident in 97% (30/31) of the cycles. The emergence of the future dominant follicle and the largest subordinate follicle of the major primary wave coincided on Day 5.7 ± 3.6 post-ovulation, whereas the secondary wave emerged on Day 19.8 ± 2.9 during estrus of the previous cycle or early diestrus. The secondary wave was often minor (93%, 28/30 cycles). Follicular deviation occurred 8.2 ± 1.4 days before the subsequent ovulation. Luteal volume increased for the first four days after ovulation and reached a maximum volume of 8.5 ± 2.7 mm3 at Day 5.4 ± 0.4, before gradually regressing after Day 15. Serum progesterone concentration increased from Day 1 after ovulation, peaking at 27.0 ± 9.6 ng/mL between 7 and 10 days after ovulation. Progesterone concentration dropped precipitously around Day 15 after ovulation and was below 2 ng/mL around Day 17 ± 2. A day effect (p < 0.0001) was observed for corpus luteum’s volume, progesterone concentration, and uterine tone, but not for endometrial edema (p > 0.05). This study helps to clarify and define normal estrous characteristics of jennies in the Eastern Caribbean.

The effect of dexamethasone and flunixin-meglumine on ovulation, endometrial oedema, and inter-ovulatory interval length in the mare

The use of flunixin-meglumine (a potent non-steroidal anti-inflammatory drug) during the critical period of intrafollicular prostaglandin production before ovulation (24 and 36 h after hCG treatment) results in a high rate of ovulatory failure and formation of haemorrhagic anovulatory follicles (HAF) in the mare. Dexamethasone is commonly used to prevent persistent mating-induced endometritis in susceptible mares, but the effect on ovulation blockage within the pre-ovulatory critical window of intrafollicular prostaglandins production following hCG administration has not been determined. Six mares were followed during four consecutive cycles in a crossover design; once in oestrus with a follicle of >32 mm in diameter, mares were treated with hCG (Hour 0) and assigned to one of 4 groups randomly: 1) FM, mares received 1.7 mg/kg flunixin-meglumine at Hour 24 and 36; 2) CON, mares received no further treatment. 3) DEX1, mares received 0.1 mg/kg dexamethasone at Hour 24, and 4) DEX2, mares received 0.1 mg/kg dexamethasone at Hour 24 and 36. For all groups, ovulation and HAF rates, endometrial oedema profiles and the inter-ovulatory intervals (IOI) were determined and compared statistically. All CON and DEX mares ovulated normally and did not form any HAF. On the contrary, FM mares developed a HAF in 83% of cycles (P < 0.01). The endometrial oedema score was lower following DEX administration than FM (P < 0.05). The mean IOI was longer (P < 0.05) in DEX1 and DEX2 groups (26.5 and 26 days, respectively) than in CON and FM groups (21.5 and 22 days, respectively). In conclusion, dexamethasone treatment given either once or twice during the critical window of hCG-induced ovulation did not block or delay ovulation, but had a similar ovulation rate than untreated control mares. However, the inter-ovulatory intervals of dexamethasone treated mares was longer than control and FM treated mares. Finally, dexamethasone treatment was more effective in reducing endometrial oedema than FM.

Relationship between estrus endometrial edema and progesterone production in pregnant mares two weeks after ovulation

BackgroundProgesterone plays a crucial role in the maintenance of pregnancy from conception to about 100–120 days of gestation when placenta becomes the main source of gestagens. The aim of the study was to test progesterone concentration 14 days after ovulation in pregnant mares and relate it to peak estral endometrial edema and the presence of intrauterine fluid (IUF) after artificial insemination (AI), the number of treatments against IUF, and the time from AI to the day when the uterus was found free of fluid.ResultsMares were divided into two groups: group A (n = 13; age 10.8 ± 4.5 years) in which a normal embryonic vesicle with a diameter ≥ 14 mm and a corpus luteum with a diameter ≥ 15 mm were found 14 days after ovulation, and group B (n = 22; age 9.4 ± 4 .0 years) in which 14 days after ovulation, a small (< 15 mm) corpus luteum and/or a small embryonic vesicle was observed (diameter < 14 mm). Mares from group A had a significantly higher progesterone concentrations at 14 days after ovulation compared with group B mares. The presence of IUF, the number of treatments against IUF, and the time from AI to the day when uterus was found free of fluid did not affect progesterone concentration measured 14 days after ovulation. In group B, a significant correlation was found between progesterone concentration measured 14 days after ovulation and endometrial edema evaluated during estrus.ConclusionsIn some cases poor development of endometrial edema during estrus can be associated with lower progesterone production 14 days after ovulation. Nevertheless, scientific explanation for this finding cannot be given based on our study.

Effect of the timing of insemination (pre- or post-ovulatory) and type of semen (refrigerated or frozen) on the sex ratio of equine offspring

The normal sex ratio of equine newborns is close to 1:1, with a slight increase of females over males, particularly when the mare is in poor physical condition (Cameron et al., Behavioral Ecology 1999 10(5):472-475). Many other factors like the age of the mare and stallion (Machado Santos et al., Theriogenology 2015 Oct 15;84(7):1238-45), maternal lineage, and uterine status of the mare (Kuhl et al., PLoS ONE 2015, Oct 5;10(10):e0139358) can influence the sex ratio as well. There are some reports describing the impact of insemination timing on the sex of newborns in humans, pigs, and cows (Roelofs et al, Ani Repro Sci. 2006 Jul;93(3-4):366-71; Martin, Hum Reprod. 1996 Aug;11(8):1812-3; Soede et al., Theriogenology 2000 Mar 1;53(4):1003-11). The present work aimed to study the effect of both the timing of insemination and the type of semen (refrigerated versus frozen) on the sex ratio in horse offspring. All the analyzed data were obtained from mares enrolled in a commercial program. In the presence of a preovulatory follicle (>35 mm) and endometrial edema, ovulation was induced by administering 2,500 IU of hCG (IM). Mares intended to be inseminated with refrigerated semen were inseminated after 24 hours from hCG injection, and if they haven't ovulated by then, theywere checked 1 or 2 times a day until ovulation was confirmed. Mares enrolled for insemination with frozen semen were controlled 3 to 4 times a day on the expected day of ovulation. The sex ratio of newborns was not influenced either by the timing of insemination or by the type of semen used (Table 1). Considering our findings, we can conclude that the insemination timing in relation to ovulation and the use of refrigerated or frozen semen, do not affect the sex of offspring in horses.

Luteal phase length, endometrial edema, and behavior differentiate post-ovulatory events in a giant panda (Ailuropoda melanoleuca).

Despite decades of reproductive research on the giant panda (Ailuropoda melanoleuca), the post-ovulatory phase continues to confound zoologists in conservation and breeding centers around the world, often resulting in significant investments of time and resources without reproductive success. The purpose of this project was to document and compare post-ovulatory characteristics during a non-productive and productive breeding in the same individual in consecutive years. A multidisciplinary approach was used to monitor the visiting female giant panda at the Toronto Zoo through the luteal phase of her first two full reproductive cycles in 2014 and 2015. Monitoring occurred via urine-endocrine analysis, weekly ultrasound examinations, and continuous behavioral observations. The 2014 reproductive cycle consisted of a pseudopregnancy, characterized by an extended luteal phase (241 days), the identification of endometrial edema and folding during ultrasound examinations, and a lack of strong association between behavior patterns and urinary progestagen secretion. The 2015 reproductive cycle included increased feeding time through the primary progestagen rise compared to the previous year, followed by simultaneous decrease in appetite and increases in inactivity, resting, sitting upright, and pre-partum-associated behaviors. These changes began 25 days before the birth of twins on Day 153 post-ovulation. Both fetuses were detected via ultrasound 15 days pre-partum. These results suggest that an absence of pre-partum behaviors, ultrasound evidence of endometrial edema without a fetus, and an extended luteal phase may be indicative of pseudopregnancy in giant pandas. Simultaneous monitoring of morphology, behavior, and urinary-endocrine profiles showed clear differences between successful and unsuccessful reproductive years.

The relationship between digital ultrasonographic image echotexture parameters of the uterus and preovulatory follicle development and ovulation in purebred Arabian mares

Objective assessment of ultrasonographic images is only possible using computer-assisted echotexture analysis. This study investigated the relationship between cyclic digital echotexture analysis of ultrasonographic uterine images, and preovulatory follicle development and ovulation in 48 cyclic purebred Arabian mares during the breeding season. When the mares’ ovarian follicle diameters exceeded 30 mm, ultrasonographic examinations were performed and ultrasonographic images recorded with uterine endometrial edema degrees following follicle development until ovulation day. Echotexture measurements, including mean grayness value (MGV), heterogeneity (HET) and contrast (CON) parameters, were performed on the days when ovarian follicle diameters reached 30 mm (Group 1, n = 12), 35 mm (Group 2, n = 12), 40 mm (Group 3, n = 12) and 45 mm (Group 4, n = 12) in images recorded the day before ovulation and on the day of ovulation. MGV was the lowest in Group 2 and the difference from the other groups was statistically significant (P&lt;0.001). CON was significantly higher in Group 2 than Groups 3 and 4 (P&lt;0.01). However, there was no significant difference compared to Group 1 (P&gt;0.05). Variations in HOM (P&lt;0.05), contrast (P&lt;0.05) and MGV (P&lt;0.01) were statistically significant on the day before ovulation and ovulation day. Thus, uterine ultrasonographic echotexture parameters are associated with preovulatory follicle development in mares, which suggests that these parameters can indicate the day of ovulation in purebred Arabian mares.

The Effects of Treatment with N-Acetyl Cysteine on Clinical Signs in Persistent Breeding-Induced Endometritis Susceptible Mares

Persistent breeding-induced endometritis (PBIE) is a major cause of infertility in mares. Endometrial inflammation that persists until embryonic descent ultimately results in early embryonic death. A poor endometrial biopsy grade (IIb or III) has been identified as a risk factor for PBIE. Intrauterine fluid accumulation (>2 cm in depth), pathologic endometrial edema, and elevated intrauterine neutrophil levels are all clinical features of PBIE. Commonly applied treatment options include uterine lavage and oxytocin therapy. N-acetyl cysteine (NAC), a mucolytic used to treat bacterial endometritis in mares, has anti-inflammatory properties and was investigated as a potential treatment for PBIE. A randomized, blinded, cross-over design clinical trial used NAC before breeding in PBIE-susceptible mares (n = 9). Intrauterine infusion of 3.3% NAC was performed 12 hours before insemination, and endometrial cytology and endometrial biopsy samples were obtained at 12 and 60 hours after insemination. Endometrial biopsies were evaluated for the degree of inflammation present. Clinical signs of endometrial edema and intrauterine fluid volumes were assessed by transrectal ultrasound at 12 and then every 24 hours after breeding. Data were analyzed using repeated measures analysis of variance and a Mann Whitney Wilcoxon Test. Treatment with NAC did not improve clinical signs in PBIE-affected mares. However, endometrial biopsies from mares treated with NAC displayed more diffuse and severe neutrophil infiltration than control cycles. Further research using a larger population of mares is required to evaluate the effects of NAC treatment on the endometrium of PBIE-susceptible mares.

Relationship between postpartum uterine involution and biomarkers of inflammation and oxidative stress in clinically healthy mares (Equus caballus)

To test the hypothesis that delayed/impaired uterine involution could be associated with oxinflammation, we studied the progression of the uterine involution in association with some biomarkers of inflammation and oxidative stress in clinically healthy mares (N = 26) during early postpartum. The examination of the reproductive tract was performed on Days 7 and 21 after foaling. Uterine involution was assessed considering: a) the increase of the gravid uterine horn diameter (GUHD) compared with diameter recorded before pregnancy during the previous breeding season; b) the level of endometrial edema (EE); c) the degree of accumulation of intrauterine fluid (IUFA); d) the status of the cervix (CS). Inflammation and oxidative stress were studied by measuring serum amyloid A (SAA), cortisol, DHEA, AOPP, protein carbonyl groups, malondialdheyde (MDA) and thiols in plasma on Days 7 and 21. By Day 21 after parturition, a significant improvement (P < 0.01) was observed for GUHD and EE; while IUFA increased in six animals. Plasma SAA and DHEA concentrations were higher when the clinical parameters indicated a lower degree of uterine involution. On Day 7, the cortisol/DHEA ratio was lower in animals with higher degree of EE. Plasma AOPP and MDA concentrations were significantly lower (P < 0.05) in animals with the lower GUHD. On Day 21, plasma MDA concentrations were significantly lower (P < 0.05) in animals with the lower IUFA. Our data suggest that a mild condition of inflammation and oxidative stress occur in mares with delayed/impaired uterine involution.

The Rat Uterus after U-74389G Process

Aim: This study co-evaluated the 4 quoted histologic variables after the lazaroid U-74389G (L) drug administration. The calculation was based on the results of 2 preliminary studies, each one evaluating two respective histologic variables of Endometrial Edema (EE) and Uterus Inflammation (UI) or Endometrial Karyorrhexis (EK) and Uterus Congestion (UC); in an induced ischemia reperfusion animal experiment. Materials and methods: The 2 main experimental endpoints at which the EE, UI and EK, UC scores were evaluated was the 60th reperfusion min (for the groups A and C) and the 120th reperfusion min (for the groups B and D). Specially, the groups A and B were processed without drugs, whereas the groups C and D after L administration. Results: The first preliminary study showed that L has a non-significant recessing potency for EE and UI histologic parameters at the “without lesions” grade 0.2636364±0.14594051 (p-values=0.0698). The second preliminary study showed that L has a non-significant recessing potency for EK and UC histologic parameters at the “without lesions” grade 0.1253529 ± 0.08529668 (p-values=0.1373) since they were co-evaluated together. These 2 studies were co-evaluated since they came from the same experimental setting. This study co-evaluated the combined diagnostic values of the four variables together. Conclusion: L administration and reperfusion time together non-significantly accentuated the 4 histologic variables within the “without lesions alterations” score 0.0758471 [-0.1464624 - +0.2981566] (p-value=0.4940).