Functional determination of emicizumab in presence of factor VIII activity.

BACKGROUND: Accurate measurement of emicizumab in the presence of factor (F) VIII is required in patients with severe hemophilia A treated with emicizumab, as well as additional need for FVIII substitution or emicizumab prophylaxis in patients with acquired or moderate to mild hemophilia A. However, the presence of FVIII potentially biases the results. OBJECTIVES: To assess the impact of plasma FVIII activity on determined emicizumab levels and evaluate different strategies for correction for or preanalytical inhibition of FVIII. METHODS: Evaluated strategies comprised of the following: (1) calculation of actual emicizumab plasma levels based on measured FVIII activities and FVIII-affected emicizumab values, (2) preanalytical heat treatment (56 °C for 40 minutes), and (3) neutralization of FVIII activity using FVIII inhibitors. Emicizumab levels and FVIII activities were measured using a modified FVIII one-stage clotting assay and a chromogenic FVIII assay based on bovine factors, respectively. RESULTS: Spiking experiments revealed a consistent linear association between FVIII activities and determined (FVIII-affected) emicizumab results at different emicizumab input levels (∼0.12 µg/mL per IU/dL of FVIII). This principally allowed for mathematical correction of measured emicizumab levels in the presence of FVIII. While a 40% to 50% activity loss of intrinsic plasma emicizumab through heat treatment was observed in patient samples, emicizumab spiked into FVIII-deficient plasma was not or only marginally affected. Application of inhibitor-based FVIII neutralization led to good agreement of results when compared with direct quantification of emicizumab by liquid chromatography-tandem mass spectrometry. CONCLUSION: Inhibitor-based FVIII neutralization appears to be a feasible strategy for accurate measurement of plasma emicizumab levels in the presence of FVIII activity.

Evaluation of a novel microfluidic chip-like device for purifying bovine frozen-thawed semen for in vitro fertilization.

The aim of this study was to validate a novel sperm purification device, the VetCount™ Harvester, for use in bovine in vitro fertilization (IVF). The device's performance was compared to BoviPure™ gradient centrifugation, a commercially available and accepted routine technique. Semen quality parameters were assessed for frozen-thawed semen from six different bulls (n = 6) following sperm purification. For each bull two semen subsamples were purified utilizing BoviPure™ gradient centrifugation and the VetCount™ Harvester, including a third subsample as untreated control. Both treatments significantly increased the proportion of progressively motile sperm cells (84.4 ± 14.1% and 85.1 ± 7.8%, respectively) compared to the untreated semen (41.9 ± 18.8%). BoviPure™ gradient and VetCount™ Harvester selected predominantly viable acrosome intact (VAI) sperm cells with low membrane fluidity and low free intracellular calcium concentration [Ca2+]i (76.5 ± 4.4% and 78.6 ± 6.0%). Normalizing [Ca2+]i of VAI sperm cells (non-treated semen: [Ca2+]i = 1) VetCount™ Harvester purified spermatozoa (0.67 ± 0.10) showed significantly lower [Ca2+]i than BoviPure™ treated sperm (0.84 ± 0.14; P < 0.05). Subsequently, the fertilizing ability of the spermatozoa was evaluated performing a competitive fertilization assay. Sperm cells from both treatment groups were fluorescently labelled using different dyes and added in equal amounts to in vitro matured oocytes. After 18 h co-incubation, the origin of the fertilizing sperm cell was evaluated via fluorescence microscopy. In two bulls, VetCount™ Harvester selected sperm that fertilized significantly more oocytes then BoviPure™ treated sperm, in another bull it was the opposite. For three bulls no difference was observed. We conclude that the VetCount™ Harvester selects a high-quality, fertile sperm fraction from frozen-thawed bull semen. However, some considerations have to be kept in mind for the direct use of the isolated sperm fraction in IVF.

Antidrug antibodies against the polyethylene glycol moiety inhibit the procoagulant activity of therapeutic polyethylene glycolated factor VIII.

BACKGROUND: The standard therapy for patients with hemophilia A (HA) is the replacement with factor VIII (FVIII) therapeutics. To overcome the limitation of short half-life of wild-type FVIII protein, polyethylene glycol (PEG) can be coupled to therapeutic FVIII to improve pharmacokinetics. OBJECTIVES: We aimed to characterize antibodies developed against a FVIII therapeutic PEGylated with a 40-kDa PEG (40PEG-BDDFVIII) in 2 patients with mild HA. METHODS: An inhouse bead-based immunoassay was developed to characterize and confirm the specificity of the detected antibodies. The neutralizing nature of the antibodies toward PEGylated therapeutics was determined by a modified Nijmegen-Bethesda assay. RESULTS: Two out of 46 patients treated with 40PEG-BDDFVIII developed inhibitory antibodies toward the drug. Switching to a non-PEGylated FVIII successfully increased the FVIII activity in both patients. In patient 1, antibodies were raised against FVIII and PEG. Anti-FVIII antibodies were of the immunoglobulin (Ig)G isotype, whereas anti-PEG antibodies were of IgG, IgM, and IgA isotypes. In patient 2, antibodies of IgG and IgA isotypes were directed only against the PEG moiety. Competitive assays confirmed the specificity of the antibodies against PEG. The applied Nijmegen-Bethesda assay revealed that patients' anti-PEG antibodies and AGP3, an antibody against the backbone of PEG, can inhibit all currently available PEGylated therapeutics but to different degrees. No inhibitory FVIII antibodies were detected. CONCLUSION: Antibodies against the PEG moiety of 40PEG-BDDFVIII abolished the efficacy of the drug. This is the first report on real-world experiences with the development of neutralizing anti-PEG antibodies after treatment with PEGylated FVIII therapeutics in mild HA.

It's a small world for parasites: evidence supporting the North American invasion of European Echinococcus multilocularis.

Echinococcus multilocularis (Em), the causative agent of human alveolar echinococcosis (AE), is present in the Holarctic region, and several genetic variants deem to have differential infectivity and pathogenicity. An unprecedented outbreak of human AE cases in Western Canada infected with a European-like strain circulating in wild hosts warranted assessment of whether this strain was derived from a recent invasion or was endemic but undetected. Using nuclear and mitochondrial markers, we investigated the genetic diversity of Em in wild coyotes and red foxes from Western Canada, compared the genetic variants identified to global isolates and assessed their spatial distribution to infer possible invasion dynamics. Genetic variants from Western Canada were closely related to the original European clade, with lesser genetic diversity than that expected for a long-established strain and spatial genetic discontinuities within the study area, supporting the hypothesis of a relatively recent invasion with various founder events.

Characterization of serum and tissue oxytocinase and tissue oxytocin in the pregnant and non-pregnant mare.

Oxytocin is a hormone with functions in: reproduction, maternal bonding, milk ejection, and feeding/social behavior, and is reported to be present in a variety of tissues. Our goal is to characterize oxytocin and leucyl and cystinyl aminopeptidase (LNPEP/oxytocinase), a key regulator of oxytocin in mares. We measured serum and tissue LNPEP by ELISA from ovulation (D0) until D21-22 in non-pregnant (n = 5) and pregnant mares (n = 6); and in periparturient and postpartum mares (n = 18). Placenta (n = 7) and homogenized tissue of diestrus mares (n = 6) were evaluated using protein determinations and LNPEP ELISAs. Identification of LNPEP and OXT protein in tissues was also performed via western blot, immunohistochemistry and liquid chromatography-mass spectrometry (LC-MS/MS). Furthermore, in situ hybridization was performed for LNPEP and OXT on endometrium, myometrium, pituitary and corpus luteum (CL). Serum LNPEP concentration were similar. Placental LNPEP U/mg protein was highest in the body and pregnant horn. The highest to lowest LNPEP U/mg protein by tissue were: myometrium > follicle wall > endometrium > kidney > CL > liver. Oxytocin was identified in the equine pituitary, CL and placenta and is likely to act in autocrine or paracrine manner, while LNPEP may act systemically and locally to regulate the availability of OXT.

Serum progesterone and oxytocinase, and endometrial and luteal gene expression in pregnant, nonpregnant, oxytocin, carbetocin and meclofenamic acid treated mares.

Our objectives were to examine changes in endometrial and luteal gene expression during estrus, diestrus, pregnancy and treatments to induce luteolysis and putatively induce luteostasis. Groups were: Diestrus (DIEST), Estrus (ESTR), Pregnant (PREG), Oxytocin (OXY), Carbetocin (CARB), and Meclofenamic acid (MFA). Blood was obtained from day (D)12 to D15 for measurement of oxytocinase, also referred to as leucyl-cysteinyl aminopeptidase (LNPEP) and progesterone. Luteal biopsies were obtained on D12 and D15 and an endometrial biopsy on D15. Real-time RT-PCR was performed for the following genes: PGR, ESR1, OXTR,OXT, LNPEP, PTGS2, PTGFR, PLA2G2C, PTGES, SLC2A4, and SLC2A1. Regarding serum LNPEP, PREG and OXY (p-value<0.001) had higher concentrations than DIEST mares. Endometrial PTGES expression was higher (p-value <0.04) in DIEST, PREG and OXY than other groups. Endometrium from ESTR had increased expression of OXT (p-value < 0.02) compared to MFA and OXY mares. Carbetocin treatment: decreased serum progesterone and LNPEP; increased endometrial PLA2G2C; decreased endometrial PTGES; and decreased luteal aromatase and PTGES. Treatment with MFA: decreased endometrial PLA2G2C, increased endometrial PTGES; and resulted in less OXTR and OXT luteal abundance on D12 compared to D15. Endometrial and luteal expression of LNPEP is affected by physiologic stage and treatment and is involved in luteal function and pregnancy recognition pathways through effects on oxytocin and prostaglandin synthesis in the horse.

Endometrial and luteal gene expression of putative gene regulators of the equine maternal recognition of pregnancy.

Our understanding of the temporal changes in endometrial and luteal gene transcripts related to the actions of oxytocin and prostaglandin during early equine pregnancy is incomplete. Additionally, the role of oxytocinase, also known as Leucyl-cystinyl aminopeptidase (LNPEP), during early pregnancy in mares has not been previously investigated. Luteal and endometrial biopsies were obtained on Day (D)8, D10, D12 and D15 post-ovulation in pregnant (PREG) and diestrus (DIEST) mares for real-time qPCR. Differences in endometrial gene expression occurred over time in: SLC2A4, SLC2A1, PTGES, OXTR and LNPEP. PTGFR and PLA2G2C had lower relative abundance in PREG D15 endometrium compared to D10. OXT and OXTR were increased on D10 and 15 PREG, respectively. Regarding luteal mRNA relative abundance, ESR1, PTGS2, PTGFR, and PTGES had higher relative abundance in D12 of DIEST and PREG. Luteal expression of OXTR and OXT had higher relative abundance in D15 compared to D8, and LNPEP had higher relative abundance in D10 and 12. Endometrial and luteal PTGES had an increased mRNA abundance in both D12 DIEST and PREG mares, which may lead to additional luteoprotective prostaglandin E2 (PGE2) secretion. Furthermore, luteal SLC2A1 had higher relative abundance in pregnancy, and likely supports the high metabolic activity of luteal tissue by increasing glucose uptake. Oxytocinase is present in endometrial and luteal tissue and its role in oxytocin induced prostaglandin secretion is uncertain.

Expression of Oxytocin/Neurophysin I and Oxytocinase in the Equine Conceptus from Day 8 to Day 21 Post-Ovulation.

Leucyl and cystinyl aminopeptidase (LNPEP/oxytocinase) is an enzyme that metabolizes oxytocin in serum and tissues. The presence of oxytocin/neurophysin I (OXT), oxytocin and LNPEP and their relationship to other genes is unknown in the equine conceptus. Our objective was to characterize gene expression of LNPEP and OXT on D8, 10, 12, 14, 15, 16 and 21 conceptuses in relationship to other genes. Immunohistochemistry, western blot and liquid chromatography with tandem mass spectrometry (LC-MS/MS) were used for identification of oxytocin and LNPEP in D15, 16 and 18 conceptuses. LNPEP was increased at D15 compared to D10, was immunolocalized in the equine trophectoderm and endoderm, and protein was confirmed by LC-MS/MS. Maximal abundance of OXT was at D21, and lowest on D12 and D14, but no protein was identified. OXTR abundance was highest on D14 and D21. LNPEP was correlated with PTGFR and PTGES on D12 and D14-D15, and high expression of PTGES, PTGS2 was found on D14, D15 and D21; PTGFR was found on D8 and D12-21. LNPEP may have a role in prostaglandin regulation and conceptus fixation by decreasing the availability of oxytocin. Further investigation on the role embryonic LNPEP during pregnancy is warranted.

Most subjectively affected joints in patients with haemophilia - what has changed after 20 years in Germany?

BACKGROUND: In patients with haemophilia (PwH), most frequently affected joints are the ankle, knee and elbow. Due to improved factor therapy in the last decades, these previous findings have to be verified in Germany. AIM: The aim of this study is to detect the most affected joint, evaluate the significance of the source of pain and determine the point prevalence of back pain in Germany today. PATIENTS AND METHODS: In a retrospective study, data of n = 300 patients with severe moderate and mild haemophilia were evaluated regarding the most affected joint, the most common source of pain, and the point prevalence of back pain. An anamnesis questionnaire and the German Pain Questionnaire were used for this assessment. RESULTS: The most affected joint in German PwH is still the ankle (41%), followed by the knee (27%) and the elbow (11%). The most common source of pain is also the ankle joint (32%). Back pain was also identified as one of the most common sources of pain, which is comparable to the elbow (elbow:15%; back:13%). The point prevalence in PwH for back pain was significantly higher compared to the general German population (P = .031). CONCLUSION: Our data showed that the ankle is still the most affected joint and the most common source of pain in Germany. These results also showed the relevance of back pain as a pain source. The evaluations also demonstrated the high point prevalence of back pain in PwH. Future therapies should also focus on the spine because joint changes affect posture.

Signal-Induced Inhibition of Telomerase Activity in HL60 Cancer Cells by Signal Transduction Using the Biophysically Activated Regulative Molecule 31 (RM31): A Pilot Study.

In this pilot study, we report the use of a novel, patented biophysical technology, which enables intranuclear access and cell nucleus stimulation, via the signal of the biophysically activated regulative molecule 31 (RM31). RM31 is the name of an isolated natural molecule found in the human body and is involved in many cellular mechanisms. We used a specific low electromagnetic field frequency to activate the RM31 molecule, which leads to specific signal transduction, to investigate the effect of telomerase activity in HL60 cancer cells. Our results revealed a dramatic inhibition in telomerase activity, a 99.5% decrease within 72 hours, with avoidance of subsequent reactivation, due to the simultaneous inhibition of human telomerase reverse transcriptase (hTERT).

Transcriptional profiling of equine endometrium before, during and after capsule disintegration during normal pregnancy and after oxytocin-induced luteostasis in non-pregnant mares.

The current study used RNA sequencing to determine transcriptional profiles of equine endometrium collected 14, 22, and 28 days after ovulation from pregnant mares. In addition, the transcriptomes of endometrial samples obtained 20 days after ovulation from pregnant mares, and from non-pregnant mares which displayed and failed to display extended luteal function following the administration of oxytocin, were determined and compared in order to delineate genes whose expressions depend on the presence of the conceptus as opposed to elevated progesterone alone. A mere fifty-five transcripts were differentially expressed between samples collected from mares at Day 22 and Day 28 of pregnancy. This likely reflects the longer-term exposure to a relatively constant, progesterone-dominated environment with little change in factors secreted by the conceptus that would affect endometrial gene expression. The complement system was amongst the canonical pathways significantly enriched in transcripts differentially expressed between Day 14 and Day 22/28 of pregnancy. The expression of complement components 7 and 8 was confirmed using in situ hybridization. The expression of SERPING1, an inhibitor of the complement system, was confirmed by immunohistochemistry. In line with the resumed capacity of the endometrium to produce prostaglandin, prostaglandin G/H synthase 1 was expressed at higher levels at Days 22 and 28 than at Day 14 of pregnancy. Our data suggest that this up-regulation is enhanced by the presence of the conceptus; samples obtained from mares at Day 20 of pregnancy had significantly higher levels of prostaglandin G/H synthase 1 transcript than mares with extended luteal function.

Loss of Ubiquitin Carboxy-Terminal Hydrolase L1 Impairs Long-Term Differentiation Competence and Metabolic Regulation in Murine Spermatogonial Stem Cells.

Spermatogonia are stem and progenitor cells responsible for maintaining mammalian spermatogenesis. Preserving the balance between self-renewal of spermatogonial stem cells (SSCs) and differentiation is critical for spermatogenesis and fertility. Ubiquitin carboxy-terminal hydrolase-L1 (UCH-L1) is highly expressed in spermatogonia of many species; however, its functional role has not been identified. Here, we aimed to understand the role of UCH-L1 in murine spermatogonia using a Uch-l1-/- mouse model. We confirmed that UCH-L1 is expressed in undifferentiated and early-differentiating spermatogonia in the post-natal mammalian testis. The Uch-l1-/- mice showed reduced testis weight and progressive degeneration of seminiferous tubules. Single-cell transcriptome analysis detected a dysregulated metabolic profile in spermatogonia of Uch-l1-/- compared to wild-type mice. Furthermore, cultured Uch-l1-/- SSCs had decreased capacity in regenerating full spermatogenesis after transplantation in vivo and accelerated oxidative phosphorylation (OXPHOS) during maintenance in vitro. Together, these results indicate that the absence of UCH-L1 impacts the maintenance of SSC homeostasis and metabolism and impacts the differentiation competence. Metabolic perturbations associated with loss of UCH-L1 appear to underlie a reduced capacity for supporting spermatogenesis and fertility with age. This work is one step further in understanding the complex regulatory circuits underlying SSC function.

Droplet digital PCR as a sensitive tool to assess exposure pressure from Echinococcus multilocularis in intermediate hosts.

A key element to understanding parasite epidemiology is assessing their prevalence in the respective wild reservoir hosts. The tapeworm Echinococcus multilocularis circulates between canid species (definite hosts) and small mammals (mostly rodents; intermediate hosts). Prevalence rates of Echinococcus multilocularis in the intermediate host are most exclusively determined through macroscopic examination of the liver generally followed by molecular or histological diagnostic for parasite species confirmation. The overall objective of the study was to investigate the suitability of Real-Time PCR and Droplet Digital PCR (ddPCR) analysis as tool to detect exposure pressure (frequency of infection events) from E. multilocularis in intermediate hosts even in the absence of macroscopic lesions in the liver. One hundred six small mammals (meadow voles and deer mice) were trapped followed by post-mortem examination including macroscopic evaluation of the liver to detect lesions indicative of infection with Echinococcus multilocularis but also by sampling a piece of liver in absence of lesion to submit it to molecular assay. Macroscopic lesions were present in the livers of two samples. Including the latter two samples, five samples yielded a positive result following Real-Time PCR, whereas 16 samples displayed three or more positive droplets upon ddPCR and were considered positive. Whether these additional cases without macroscopic lesions would have become infectious during the lifespan of the rodent or were abortive or early infections is unclear, but these data suggest levels of exposure of intermediate hosts to the parasite is much higher than assumed.

Unique metabolic phenotype and its transition during maturation of juvenile male germ cells.

Human male reproductive development has a prolonged prepubertal period characterized by juvenile quiescence of germ cells with immature spermatogonial stem cell (SSC) precursors (gonocytes) present in the testis for an extended period of time. The metabolism of gonocytes is not defined. We demonstrate with mitochondrial ultrastructure studies via TEM and IHC and metabolic flux studies with UHPLC-MS that a distinct metabolic transition occurs during the maturation to SSCs. The mitochondrial ultrastructure of prepubertal human spermatogonia is shared with prepubertal pig spermatogonia. The metabolism of early prepubertal porcine spermatogonia (gonocytes) is characterized by the reliance on OXPHOS fuelled by oxidative decarboxylation of pyruvate. Interestingly, at the same time, a high amount of the consumed pyruvate is also reduced and excreted as lactate. With maturation, prepubertal spermatogonia show a metabolic shift with decreased OXHPOS and upregulation of the anaerobic metabolism-associated uncoupling protein 2 (UCP2). This shift is accompanied with stem cell specific promyelocytic leukemia zinc finger protein (PLZF) protein expression and glial cell-derived neurotropic factor (GDNF) pathway activation. Our results demonstrate that gonocytes differently from mature spermatogonia exhibit unique metabolic demands that must be attained to enable their maintenance and growth in vitro.

Repetitive in vivo manual loading of the spine elicits cellular responses in porcine annuli fibrosi.

Back pain and intervertebral disc degeneration are prevalent, costly, and widely treated by manual therapies, yet the underlying causes of these diseases are indeterminate as are the scientific bases for such treatments. The present studies characterize the effects of repetitive in vivo manual loads on porcine intervertebral disc cell metabolism using RNA deep sequencing. A single session of repetitive manual loading applied to the lumbar spine induced both up- and down-regulation of a variety of genes transcribed by cells in the ventral annuli fibrosi. The effect of manual therapy at the level of loading was greater than at a level distant to the applied load. Gene ontology and molecular pathway analyses categorized biological, molecular, and cellular functions influenced by repetitive manual loading, with over-representation of membrane, transmembrane, and pericellular activities. Weighted Gene Co-expression Network Analysis discerned enrichment in genes in pathways of inflammation and skeletogenesis. The present studies support previous findings of intervertebral disc cell mechanotransduction, and are the first to report comprehensively on the repertoire of gene targets influenced by mechanical loads associated with manual therapy interventions. The present study defines the cellular response of repeated, low-amplitude loads on normal healthy annuli fibrosi and lays the foundation for future work defining how healthy and diseased intervertebral discs respond to single or low-frequency manual loads typical of those applied clinically.

Molecular characterization of Giardia spp. and Cryptosporidium spp. from dogs and coyotes in an urban landscape suggests infrequent occurrence of zoonotic genotypes.

Giardia spp. and Cryptosporidium spp. are common gastrointestinal parasites with the potential for zoonotic transmission. This study aimed to (1) determine the genotypes occurring in dogs and coyotes occupying a similar urban area; (2) determine if these hosts were infected with potentially zoonotic genotypes; (3) provide baseline molecular data. In August and September 2012, 860 dog owners living in neighborhoods bordering six urban parks in Calgary, Alberta, Canada, provided faecal samples from their dogs. From March 2012 through July 2013, 193 coyote faeces were also collected from five of six of the same parks. Direct immunofluorescence microscopy (DFA) indicated that Giardia spp. and Cryptosporidium spp. infected a total of 64 (7.4%) and 21 (2.4%) dogs, as well as 15 (7.8%) and three (1.6%) coyotes, respectively. Semi-nested, polymerase chain reactions targeting the 16S small-subunit ribosomal ribonucleic acid (SSU rRNA) and 18S SSU rRNA genes of Giardia spp. and Cryptosporidium spp., respectively, were conducted on samples that screened positive by DFA, and products were sequenced and genotyped. Dogs were infected with Giardia intestinalis canid-associated assemblages C (n = 14), D (n = 13), and Cryptosporidium canis (n = 3). Similarly, G. intestinalis assemblages C (n = 1), D (n = 1) and C. canis (n = 1), were detected in coyotes, as well as G. intestinalis assemblage A (n = 1) and Cryptosporidium vole genotype (n = 1). Dogs and coyotes were predominantly infected with host-specific genotypes and few potentially zoonotic genotypes, suggesting that they may not represent a significant risk for zoonotic transmission of these parasites in urban areas where these hosts are sympatric.

Fibrinogen in equine pregnancy as a mediator of cell adhesion, an epigenetic and functional investigation.

Preimplantation equine embryos synthesize and secrete fibrinogen, which is a peculiar finding as fibrinogen synthesis almost exclusively occurs in the liver. This study investigated the hypothesis that conceptus-derived fibrinogen mediates cell adhesion during fixation. On day 21 of pregnancy, five integrin subunits, including ITGA5, ITGB1, ITGAV, and ITGB1, displayed significantly higher transcript abundance than on day 16 of pregnancy. Endometrial epithelial cells adhered to fibrinogen in an integrin-dependent manner in an in vitro cell adhesion assay. Bilaminar trophoblast and allantochorion expressed fibrinogen transcript, indicating that fibrinogen expression persists past fixation. Preimplantation-phase endometrium, conceptuses, and microcotyledonary tissue expressed components of the clotting cascade regulating fibrin homeostasis, leaving open the possibility that fibrinogen is converted to fibrin. Fibrinogen is likely to have functions beyond mediating cell adhesion, such trapping growth factors and triggering signaling cascades, and has remarkable parallels to the expression of fibrinogen by some tumors. The deposition of fibrinogen within tumor stroma is characteristic of breast carcinoma, and tumor-derived fibrinogen has been implicated in the metastatic potential of circulating tumor cells. DNA methylation of the fibrinogen locus in equine conceptuses was examined in comparison to liver and endometrium, and across the full gene cluster, was significantly higher for endometrium than liver and conceptus. DNA methylation of regulatory regions did not differ between liver and conceptus, and was significantly lower than in endometrium. These results, therefore, support the hypothesis of DNA methylation being a regulator of fibrinogen expression in the conceptus.

Deslorelin and naltrexone stimulate follicular development in mares during autumn transition and early anestrus.

Horses are long-day breeders and commence ovarian follicular activity during the spring. Evidence suggests that there is an endogenous circannual rhythm in mares, and it is uncertain whether hormonal manipulation during or immediately following the fall transition induces follicular development. The current study was designed to test the hypothesis that both deslorelin and naltrexone induce follicular development in late fall transitioning or anestrous mares. Five of six mares treated with deslorelin, and 4 of 6 mares treated with naltrexone, developed a pre-ovulatory-sized follicle and were inseminated. Zero of three deslorelin-control mares and 1 of 3 naltrexone-control mares were inseminated. The number of mares bred in the deslorelin treatment group was significantly higher than in the corresponding control group (P < 0.05). Six of nine mares inseminated were pregnant 14 days after insemination. In conclusion, we were able to induce follicular development resulting in fertile ovulations during and shortly after the fall transition.

Stimulation du développement folliculaire par le deslorelin et le naltrexone chez des juments durant la transition automnale et le début de l'anoestrus. Les chevaux sont des reproducteurs saisonniers influencés par la lumière du jour et l'activité folliculaire ovarienne débute au printemps. Les évidences suggèrent que chez les juments il y a un rythme circannuel endogène, et il est incertain si une manipulation hormonale durant ou immédiatement après la transition automnale induit le développement folliculaire. La présente étude a été conçue afin de vérifier l'hypothèse que le deslorelin et le naltrexone induisent le développement folliculaire tard à l'automne lors de la période de transition ou chez des juments en anoestrus. Cinq des six juments traitées avec du deslorin et quatre des six juments traitées avec du naltrexone ont développé un follicule de taille pré-ovulatoire et ont été inséminées. Aucune des trois juments témoins pour le deslorin et une des trois juments témoins pour le naltrexone furent inséminées. Le nombre de juments saillies dans le groupe de traitement deslorin était significativement supérieur à celui du groupe témoin correspondant (P < 0,05). Six des neuf juments inséminées étaient gestantes 14 jours après l'insémination. En conclusion, nous avons été en mesure d'induire le développement folliculaire résultant en des ovulations fertiles durant et tôt après la transition automnale.(Traduit par Dr Serge Messier).

Congenital hydrocephalus in a Belgian draft horse associated with a nonsense mutation in B3GALNT2.

Congenital hydrocephalus has been reported for a number of horse breeds, and for Friesian horses this condition has been associated with a nonsense mutation of B3GALNT2. We report the first case of congenital hydrocephalus associated with the said mutation in a Belgian draft horse. Genetic testing and consideration of the testing results in breeding programs are warranted.

Hydrocéphalie congénitale chez un cheval de trait Belge associée à une mutation non-sens de B3GALNT2. L'hydrocéphalie congénitale a été signalée pour plusieurs races de chevaux et, pour les chevaux Frisons, cette affection a été associée à une mutation non-sens de B3GALNT2. Nous signalons le premier cas d'hydrocéphalie congénitale associée à cette mutation chez un cheval de trait Belge. Les tests génétiques et la considération des résultats des tests sont justifiés dans le cadre des programmes d'élevage.(Traduit par Isabelle Vallières).