Manipulation of follicle development to ensure optimal oocyte quality and conception rates in cattle

Over the last several decades, a number of therapies have been developed that manipulate ovarian follicle growth to improve oocyte quality and conception rates in cattle. Various strategies have been proposed to improve the responses to reproductive biotechnologies following timed artificial insemination (TAI), superovulation (SOV) or ovum pickup (OPU) programmes. During TAI protocols, final follicular growth and size of the ovulatory follicle are key factors that may significantly influence oocyte quality, ovulation, the uterine environment and consequently pregnancy outcomes. Progesterone concentrations during SOV protocols influence follicular growth, oocyte quality and embryo quality; therefore, several adjustments to SOV protocols have been proposed depending on the animal category and breed. In addition, the success of in vitro embryo production is directly related to the number and quality of cumulus oocyte complexes harvested by OPU. Control of follicle development has a significant impact on the OPU outcome. This article discusses a number of key points related to the manipulation of ovarian follicular growth to maximize oocyte quality and improve conception rates following TAI and embryo transfer of in vivo-and in vitro-derived embryos in cattle.

Video laparoscopic intervention for an interstitial pregnancy after failure of clinical treatment

CONTEXT: Interstitial pregnancy is a rare form of ectopic pregnancy for which the best therapeutic course of action has yet to be determined. Surgical intervention entails a high risk of hemorrhage due to the great vascularization of the cornual region of the uterus. Case descriptions facilitate the analysis of results and aid clinicians in determining the most appropriate course of action in these situations. CASE REPORT: In a patient with an ultrasound diagnosis of interstitial pregnancy, clinical treatment using methotrexate was chosen. However, after one week, there was a marked decline in the serum level of the β subunit of chorionic gonadotropin hormone, although an ultrasound examination revealed embryonic cardiac activity. A second dose of the chemotherapy was administered. Embryonic cardiac activity persisted 48 hours later. Video laparoscopy was performed to achieve right-side cornual resection, which resulted in satisfactory resolution of the case.

Prostaglandin treatment at the onset of norgestomet and estradiol-based synchronization protocols did not alter the ovarian follicular dynamics or pregnancy per timed artificial insemination in cyclic Bos indicus heifers

The aim of the present study was to evaluate the effects of the PGF2˛treatment givenat the onset of a synchronization of ovulation protocol using a norgestomet (NORG) earimplant on ovarian follicular dynamics (Experiment 1) and pregnancy per AI (P/AI; Exper-iment 2) in cyclic (CL present) Bos indicus heifers. In Experiment 1, a total of 46 heiferswere presynchronized using two consecutive doses of PGF2˛12 days apart. At first dayof the synchronization protocol the heifers received implants containing 3 mg of NORGand 2 mg of estradiol benzoate (EB). At the same time, heifers were randomly assignedto receive 150 mg of d-cloprostenol (n = 23; PGF2˛) or no additional treatment (n = 23;Control). When the ear implants were removed 8 days later, all heifers received a PGF2˛treatment and 1 mg of EB was given 24 h later. The follicular diameter and interval toovulation were determined by transrectal ultrasonography. No effects of PGF2˛treat-ment on the diameter of the largest follicle present were observed at implant removal(PGF2˛= 9.8 ± 0.4 vs. Control = 10.0 ± 0.3 mm; P = 0.73) or after 24 h (PGF2˛= 11.1 ± 0.4 vs.Control = 11.0 ± 0.4 mm; P = 0.83). No differences in the time of ovulation after ear implantremoval (PGF2˛= 70.8 ± 1.2 vs. Control = 73.3 ± 0.9 h; P = 0.10) or in the ovulation rate(PGF2˛= 87.0 vs. Control = 82.6%; P = 0.64) between treatments were observed. In Experi-ment 2, 280 cyclic heifers were synchronized using the same experimental design describedabove (PGF2˛; n = 143 and Control; n = 137), at random day of the estrous cycle. All heifersreceived 300 IU of equine chorionic gonadotropin (eCG) and 0.5 mg of estradiol cypionate(as ovulatory stimulus) when the NORG ear implants were removed. Timed artificial insem-ination (TAI) was performed 48 h after implant removal and the pregnancy diagnosis wasconducted 30 days later. No effects on the P/AI due to PGF2˛treatment were observed(PGF2˛= 51.7 vs. Control = 57.7%; P = 0.29). In conclusion, PGF2˛treatment at the onset ofNORG-based protocols for the synchronization of ovulation did not alter the ovarian follic-ular responses or the P/AI in cyclic Bos indicus beef heifers synchronized for TAI.

Exogenous gonadotropins do not increase the blood-follicular transportation capacity of extra-ovarian hormones such as prolactin and cortisol.

BACKGROUNDS In vitro fertilization involves high dosage gonadotropin stimulation, which apparently has some negative impact on follicular endocrine function. As chorionic gonadotropin stimulation has been shown to increase the blood-follicular permeability in animal models, this raises the question if such an effect also applies to gonadotropins in humans, possibly affecting the endocrine follicular milieu. FINDINGS Follicular fluid and serum were collected at the time of follicular aspiration in in vitro fertilisation without (Natural cycle IVF, n = 24) and with (conventional gonadotropin stimulated IVF, n = 31) gonadotropin stimulation. The concentration of the extra-ovarian hormones prolactin and cortisol were analysed by immunoassays. RESULTS Median serum prolactin and cortisol concentrations were 12.3 ng/mL and 399 nmol/L without versus 32.2 ng/mL and 623 nmol/L with gonadotropin stimulation. The corresponding concentrations in follicular fluid were 20.6 ng/mL and 445 nmol/L versus 28.8 ng/ml and 456 nmol/L for prolactin and cortisol. As a consequence, mean follicular fluid:serum ratios were significantly reduced under gonadotropin stimulation (prolactin p = 0.0138, cortisol p = 0.0001). As an enhanced blood-follicular permeability and transportation, induced by gonadotropin stimulation, would result in increased instead of decreased follicular fluid:serum ratios as found in this study, it can be assumed that this does not affect extra-ovarian protein and steroid hormones as illustrated by prolactin and cortisol. CONCLUSIONS The model of serum follicular fluid:serum ratio of hormones, produced outside the ovaries, did not reveal a gonadotropin induced increased blood-follicular transportation capacity. Therefore it can be assumed that the effect of gonadotropins on follicular endocrine function is not due to an increased ovarian permeability of extra-ovarian hormones.

Low-dosage clomiphene reduces premature ovulation rates and increases transfer rates in natural-cycle IVF

Natural-cycle IVF has been suggested as an alternative IVF treatment. However, efficacy is limited due to high premature ovulation rates, resulting in low transfer rates. This study investigates whether low dosages of clomiphene citrate reduce premature ovulation rate and increase transfer rate. Of 112 women included (aged 35.2 ± 4.5 years) 108 underwent one natural-cycle IVF cycle with human chorionic gonadotrophin (HCG) to induce ovulation and 103 underwent one natural-cycle IVF cycle with 25 mg/day clomiphene from about day 7 until HCG administration. Before retrieval, 1.2 monitoring consultations per cycle were required. Clomiphene reduced premature ovulation rate, from 27.8% without to 6.8% with clomiphene (P < 0.001) and increased transfer rate from 39.8% to 54.4% (P = 0.039). Clinical pregnancy rates without and with clomiphene were 27.9% versus 25.0% per transfer and 11.1% versus 13.6% per initiated cycle. Use of clomiphene resulted in mild hot flushes and headache in 5% of patients. Nausea and persisting ovarian cyst formation was not observed. In conclusion, clomiphene citrate led to very few side effects, required 1.2 monitoring consultations, significantly reduced premature ovulation rate and significantly increased transfer rate per initiated cycle, an effect which was not age dependent.

Historias de hormonas en Argentina : La obesidad de los niños y el diagnóstico precoz del embarazo en las décadas de 1930 y 1940

Este artículo aborda, desde una perspectiva de género, la producción de saberes sobre hormonas en Argentina, en las décadas de 1930 y 1940. Entendemos que un análisis histórico de las ideas científicas y las prácticas clínicas permite indagar en cómo éstas se entraman tanto con el escenario social del que forman parte como con los contextos institucionales donde se elaboran. Focalizaremos en las miradas de los endocrinólogos del Hospital de Niños de Buenos Aires sobre la obesidad en la infancia y el síndrome adiposo genital, y los debates en la Sociedad de Obstetricia y Ginecología de Buenos Aires sobre las técnicas de detección precoz del embarazo y la hormona gonadotropina coriónica

Historias de hormonas en Argentina : La obesidad de los niños y el diagnóstico precoz del embarazo en las décadas de 1930 y 1940

Este artículo aborda, desde una perspectiva de género, la producción de saberes sobre hormonas en Argentina, en las décadas de 1930 y 1940. Entendemos que un análisis histórico de las ideas científicas y las prácticas clínicas permite indagar en cómo éstas se entraman tanto con el escenario social del que forman parte como con los contextos institucionales donde se elaboran. Focalizaremos en las miradas de los endocrinólogos del Hospital de Niños de Buenos Aires sobre la obesidad en la infancia y el síndrome adiposo genital, y los debates en la Sociedad de Obstetricia y Ginecología de Buenos Aires sobre las técnicas de detección precoz del embarazo y la hormona gonadotropina coriónica

Historias de hormonas en Argentina : La obesidad de los niños y el diagnóstico precoz del embarazo en las décadas de 1930 y 1940

Este artículo aborda, desde una perspectiva de género, la producción de saberes sobre hormonas en Argentina, en las décadas de 1930 y 1940. Entendemos que un análisis histórico de las ideas científicas y las prácticas clínicas permite indagar en cómo éstas se entraman tanto con el escenario social del que forman parte como con los contextos institucionales donde se elaboran. Focalizaremos en las miradas de los endocrinólogos del Hospital de Niños de Buenos Aires sobre la obesidad en la infancia y el síndrome adiposo genital, y los debates en la Sociedad de Obstetricia y Ginecología de Buenos Aires sobre las técnicas de detección precoz del embarazo y la hormona gonadotropina coriónica

Induction of ovulation in rabbit does using purified nerve growth factor and camel seminal plasma

The presence of an ovulation-inducing factor (OIF) in the seminal plasma (SP) of several species with spontaneous and induced ovulation, including the rabbit, has been documented. Recent studies have demonstrated that the OIF in the SP of camels (SPCAM) is a nerve growth factor (β-NGF). The aim of this study was to determine if purified β-NGF from mouse submandibular glands or SPCAM could provoke ovulation induction in the rabbit doe. A total of 35 females were synchronized with 25 IU of equine chorionic gonadotropin (Serigan, Laboratorios Ovejero, Spain) and allocated into 4 groups. Forty-eight hours later (Day 0), does were given a single dose (IM) of 1 mL of saline solution (SS; n = 8); 1 mL of gonadorelin (GnRH; Inducel, Laboratorios Ovejero, Spain; n = 9); 24 µg of β-NGF (2.5S-NGF; Promega, USA; n = 10); or 1 mL of centrifuged raw camel SP (SPCAM; 127 pg mL–1 NGF; n = 8). After treatment, an empty catheter was introduced through the vagina to simulate the nervous/mechanical stimulus of coitus (4 animals per group). Plasma LH concentrations were determined in blood samples taken 30 min before treatment and at 0, 30, 60, 90, and 120 min after injection. Progesterone concentrations were assessed at 0 and 120 min and every 2 days until Day 6 after treatment. Concentrations of β-NGF in camel SP and hormone determinations were made by enzyme immunoassay. Ovulation rate (OR) was determined after euthanasia on Day 7.

A medical management of interstitial ectopic pregnancy: A 5-year clinical study

Background: Medical treatment of the rare interstitial ectopic pregnancy with methotrexate has been considered an alternative to surgical resection. Aim: To determine the treatment success rate with a single-dose intravenous methotrexate/folinic acid regimen and to identify predictors of treatment outcome. Methods: A 5-year audit (April 2000-August 2005) was carried out, collecting clinical imaging data and serum beta-human chorionic gonadotrophin (beta-hCG). Time taken for complete beta-hCG resolution was recorded, and a negative beta-hCG result was used as an endpoint of successful outcome. Results: Of the 13 cases, two required urgent surgery for rupture on presentation. In the remaining 11 cases, intravenous methotrexate (300 mg) was used, with oral folinic acid rescue (15 mg x 4 doses). There were no side-effects. Complete beta-hCG resolution was achieved in 10 of the 11 medically treated cases (91% success rate), requiring 21-129 days. Successful outcome was seen with initial beta-hCG level as high as 106 634 IU/L and gestation sac as large as 6 cm and a live fetus. Conclusion: The methotrexate/folinic acid regimen used as a one-dose treatment is safe and effective for unruptured interstitial pregnancy, with no side-effects and the advantage of avoiding invasive surgery. Subsequent tubal patency and reproductive function are yet to be ascertained.

Use of a GnRH agonist and hCG to obtain an index of testosterone secretory capacity in the koala (Phascolarctos cinereus)

Testosterone secretion in mammals typically occurs in random pulses such that a single blood sample provides limited information on reproductive endocrine status. However, it has been shown in several species that an index of the prevailing testosterone biosynthetic capacity of the testes can be obtained by measuring the increase in circulating testosterone after injection of a GnRH agonist or human chorionic gonadotrophin (hCG). Hence, the aims of the present study were to examine fluctuations in testosterone secretion in the koala (n = 6) over a 24-hour period and then characterise testosterone secretion after injection of the GnRH agonist buserelin (4 mu g) or hCG (1000 IU). The latter was used to establish an index of the prevailing testosterone biosynthetic capacity of the koala testis. Individual koalas showed major changes in blood testosterone concentrations over 24 hours, but there was no apparent diurnal pattern of testosterone secretion (P >.05). Injection of buserelin and hCG resulted in an increase (P

Gonadotropin-releasing hormone type II antagonist induces apoptosis in MCF-7 and triple-negative MDA-MB-231 human breast cancer cells in vitro and in vivo

Triple-negative breast cancer does not express estrogen and progesterone receptors, and no overexpression/amplification of the HER2-neu gene occurs. Therefore, this subtype of breast cancer lacks the benefits of specific therapies that target these receptors. Today chemotherapy is the only systematic therapy for patients with triple-negative breast cancer. About 50% to 64% of human breast cancers express receptors for gonadotropin-releasing hormone (GnRH), which might be used as a target. New targeted therapies are warranted. Recently, we showed that antagonists of gonadotropin-releasing hormone type II (GnRH-II) induce apoptosis in human endometrial and ovarian cancer cells in vitro and in vivo. This was mediated through activation of stress-induced mitogen-activated protein kinases (MAPKs) p38 and c-Jun N-terminal kinase (JNK), followed by activation of proapoptotic protein Bax, loss of mitochondrial membrane potential, and activation of caspase-3. In the present study, we analyzed whether GnRH-II antagonists induce apoptosis in MCF-7 and triple-negative MDA-MB-231 human breast cancer cells that express GnRH receptors. In addition, we ascertained whether knockdown of GnRH-I receptor expression affects GnRH-II antagonist-induced apoptosis and apoptotic signaling.