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See detailEndocrine disrupting effects of zearalenone, alpha- and beta-zearalenol at the level of nuclear receptor binding and steroidogenesis.
Frizzell, C; Ndossi, D; Verhaegen, S et al

in Toxicology Letters (2011), 206(2), 210-217

The mycotoxin zearalenone (ZEN) is a secondary metabolite of fungi which is produced by certain species of the genus Fusarium and can occur in cereals and other plant products. Reporter gene assays ... [more ▼]

The mycotoxin zearalenone (ZEN) is a secondary metabolite of fungi which is produced by certain species of the genus Fusarium and can occur in cereals and other plant products. Reporter gene assays incorporating natural steroid receptors and the H295R steroidogenesis assay have been implemented to assess the endocrine disrupting activity of ZEN and its metabolites alpha-zearalenol (alpha-ZOL) and beta-zearalenol (beta-ZOL). alpha-ZOL exhibited the strongest estrogenic potency (EC(50) 0.022+/-0.001 nM), slightly less potent than 17-beta estradiol (EC(50) 0.015+/-0.002 nM). ZEN was ~70 times less potent than alpha-ZOL and twice as potent as beta-ZOL. Binding of progesterone to the progestagen receptor was shown to be synergistically increased in the presence of ZEN, alpha-ZOL or beta-ZOL. ZEN, alpha-ZOL or beta-ZOL increased production of progesterone, estradiol, testosterone and cortisol hormones in the H295R steroidogenesis assay, with peak productions at 10 muM. At 100 muM, cell viability decreased and levels of hormones were significantly reduced except for progesterone. beta-ZOL increased estradiol concentrations more than alpha-ZOL or ZEN, with a maximum effect at 10 muM, with beta-ZOL (562+/-59 pg/ml)>alpha-ZOL (494+/-60 pg/ml)>ZEN (375+/-43 pg/ml). The results indicate that ZEN and its metabolites can act as potential endocrine disruptors at the level of nuclear receptor signalling and by altering hormone production. [less ▲]

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See detailComparison of accuracy of ultrasonography, progesterone and pregnancy-associated 4 glycoprotein tests for pregnancy diagnosis in semi-domesticated reindeer
Savela, Hannele; Vahtiala, S.; Lindeberg, H. et al

in Theriogenology (2009), 72

The aim of the study was to compare transrectal ultrasound with progesterone (P4) and pregnancy-associated glycoproteins (PAG) as pregnancy detection methods for semi-domesticated reindeer in field ... [more ▼]

The aim of the study was to compare transrectal ultrasound with progesterone (P4) and pregnancy-associated glycoproteins (PAG) as pregnancy detection methods for semi-domesticated reindeer in field conditions. Female reindeer (n=195) were scanned transrectally by a 7.5 MHz linear array transducer and blood sampled either in Dec 2005 (n=33), Dec 2006 (n=92) or Jan 2007 (n=70) during early- or mid-gestation. Plasma levels of P4 and PAG were assessed by RIA. Based on calving records, the sensitivity, specificity, predictive values and the overall accuracy of the three tests were calculated. The overall calving rate calculated from the calving records was 86.2%. The overall accuracy of transrectal ultrasound was 99.5%. The sensitivity and specificity of transrectal ultrasound were 99.4% and 100%, respectively. In the plasma P4 test, the threshold level of 5.5 nmol/L gave the highest overall accuracy (93.3%). The sensitivity of the P4 test decreased from 96.4% to 81.5%, when the threshold level increased from 5.0 nmol/L to 8.0 nmol/L, while the specificity remained at 85.2% over the range of these cut-off values. The overall accuracy of the plasma PAG test decreased from 96.4% to 64.1% when the plasma PAG threshold level increased from 0.5 ng/mL to 3.5 ng/mL, whereas sensitivity decreased from 99.4% to 58.3%. Specificity increased from 77.8% to 100% when the plasma PAG threshold level reached 3.0 ng/mL. Transrectal ultrasound showed higher diagnostic values than plasma P4-RIA and PAG-RIA in diagnosing pregnancy of reindeer, with the advantage that diagnoses can be made in real-time in field conditions [less ▲]

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See detailComparison of transrectal ultrasound and plasma pregnancy-associated glycoprotein (PAG) as pregnancy tests of reindeer
Savela, H.; Vahtiala, S.; Lindeberg, H. et al

in Proceedings of the 16th International Congress on Animal Reproduction (2008)

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See detailPregnancy associated glycoproteins (PAG) in postpartum cows, ewes, goats and their offspring
Haugejorden, G.; Waage, S.; Dahl, E. et al

in Theriogenology (2006), 66(8), 1976-1984

Determination of plasma concentrations of pregnancy associated glycoproteins (PAG) has been used for early pregnancy diagnosis in cows. However, this is complicated by the presence of PAG in plasma for an ... [more ▼]

Determination of plasma concentrations of pregnancy associated glycoproteins (PAG) has been used for early pregnancy diagnosis in cows. However, this is complicated by the presence of PAG in plasma for an extended period postpartum. The main objective of the present study was to investigate the postpartum elimination rates of pregnancy associated glycoproteins (PAG) in sheep, goats and cows in order to gain background information applicable to the use of PAG for pregnancy diagnosis in domestic ruminants. A second objective was to investigate whether PAG are transferred to the foetus and newborn, by measuring plasma PAG concentrations in calves, lambs and goat kids before and after colostrum feeding. PAG in the blood at parturition were eliminated by a first order process in the cows and ewes, while a two-step log-linear decline occurred in the goats. Estimated postpartum half-life of plasma PAG in the cows and ewes was 9 and 4.5 days, respectively. In the goats, half-lives were 3.6 and 7.5 days in the initial fast and terminal slow phase. Basal levels were reached 80-90 days postpartum in cows. Plasma PAG concentration can be used for pregnancy diagnosis from day 28 after AI, provided that the time interval from calving to AI is > 60 days. Using a heterologous antibody RIA, we found 4 ng/mL to be the appropriate cut-off. Due to the presence of PAG residues from the previous gestation, the interval from AI to pregnancy diagnosis should increase by approximately 0.5 days beyond 28 days for each day of AI closer to calving than 60. Measurements in newborn ruminants suggested that PAG enter the foetal blood in utero and that colostral PAG are transferred to the newborn. Following the peak plasma concentration observed 1 day after birth in most of the animals, PAG were rapidly eliminated in a log-linear fashion. [less ▲]

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See detailEndocrinology of pregnancy and early pregnancy detection by reproductive hormones in reindeer (Rangifer tarandus tarandus)
Ropstad, E.; Veiberg, V.; Sakkinen, H. et al

in Theriogenology (2005), 63(6), 1775-1788

The endocrinology was studied throughout pregnancy in reindeer (Rangifer tarandus tarandus) located in Oulu, Finland (65 degrees N, 25 degrees E) with 13 captive, semi domestic adult females. Blood ... [more ▼]

The endocrinology was studied throughout pregnancy in reindeer (Rangifer tarandus tarandus) located in Oulu, Finland (65 degrees N, 25 degrees E) with 13 captive, semi domestic adult females. Blood samples were analyzed for plasma progesterone (P4), estradiol (E,) and estrone sulphate (E1SO4), 15-ketodihydro-PGF(2 alpha) (PG-metabolite) and pregnancy associated glycoproteins (PAG). The mean plasma P4 concentration peaked twice during gestation: at around 24 and three weeks prior to calving. In pregnant females the plasma PAG concentration increased over basal concentrations 21-30 days after the estimated day of conception and peaked at the time of calving. The concentrations of E, and E1SO4 remained low until 60 days before calving when a rapid increase was found for both hormones. The mean plasma concentration of PG-metabolite increased throughout pregnancy to a maximum at parturition. The estimated mean (range) gestation length was 216 (212-220) days. Judged from measures on reproductive organs collected from 86 free-ranging, semi-domestic female reindeer of unknown age presented for slaughter at Roros, Norway (63 degrees N, 11 degrees E) in the second week of December 1999, it was concluded that the breeding season lasted from early September until the end of November. The results also showed that plasma PAG concentration could provide a tool for detection of pregnancy in reindeer [less ▲]

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See detailPregnancy-associated glycoproteins (PAG) in postpartum cows, ewes, goats and their offspring
Haugejorden, G.; Dahl, E.; Karlberg, K. et al

in Proceedings of the 15th International Congress on Animal Reproduction (2004)

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See detailEndocrine profiles, haematology and pregnancy outcomes of late pregnant Holstein dairy heifers sired by bulls giving a high or low incidence of stillbirth
Kornmatitsuk, B.; Dahl, E.; Ropstad, E. et al

in Acta Veterinaria Scandinavica (2004), 45(1-2), 47-68

The high incidence of stillbirth in Swedish Holstein heifers has increased continuously during the last 15 years to an average of 11% today. The pathological reasons behind the increased incidence of ... [more ▼]

The high incidence of stillbirth in Swedish Holstein heifers has increased continuously during the last 15 years to an average of 11% today. The pathological reasons behind the increased incidence of stillbirth are unknown. The present experiment was undertaken to investigate possible causes of stillbirth and to study possible physiological markers for predicting stillbirth. Twenty Swedish Holstein dairy heifers sired by bulls with breeding values for a high risk of stillbirth (n = 12) (experimental group) and a low risk of stillbirth (n = 8) (control group, group B) were selected based on information in the Swedish A1-data base. The experimental group consisted of 2 subgroups of heifers (groups A1 and A2) inseminated with 2 different bulls with 3.5% and 9% higher stillbirth rates than the average, and the control group consisted of heifers pregnant with 5 different bulls with 0%-6% lower stillbirth rates than the average. The bull used for group A1 had also calving difficulties due to large calves as compared to the bull in group A2 showing no calving difficulties. The heifers were supervised from 6-7 months of pregnancy up to birth, and the pregnancies and parturitions were compared between groups regarding hormonal levels, haematology, placental characteristics and calf viability. In group A1, 1 stillborn, 1 weak and 4 normal calves were recorded. In group A2, 2 stillborn and 4 normal calves were registered. All animals in the control group gave birth to a normal living calf without any assistance. The weak calf showed deviating profiles of body temperature, saturated oxygen and heart rates, compared with the normal living calves. No differences of the placentome thickness, measured in vivo by Ultrasonography were seen between the groups. The number of leukocytes and differential cell counts in groups A1 and A2 followed the profiles found in the control group. In group A1, a slight decrease of oestrone sulphate (E1S04) levels was found in the animal delivering a stillborn calf from the first 24-h blood sampling at 6 weeks to the second at 3 weeks prior to delivery, while the levels of E1S04 at both periods in the animal delivering a weak calf followed the profile in animals delivering a normal living calf. During late pregnancy and at the time of parturition, the levels of E1SO4 and PAGs in animals delivering a stillborn or weak calf (from group A1) followed the normal profiles found in animals delivering a normal living calf. In group A2, low levels of E1SO4 and pregnancy associated glycoproteins (PAGs) over 24 h at both 3 and 6 weeks prior to parturition (<1.5 nmol/L) were recorded in animals delivering a stillborn calf During late pregnancy and parturition, the levels of E1SO4 and PAGs were slightly lower during 30-50 days prior to delivery and increased with a lower magnitude at the time of parturition. In conclusion, our results indicate that the aetiology behind stillbirth varies depending on the AI-bulls used and is associated with dystocia or low viability of the calves. Deviating profiles of oestrone sulphate (E1SO4) and pregnancy associated glycoproteins (PAGs) in animals delivering a stillborn calf not caused by dystocia were observed, suggesting placental dysfunction as a possible factor. The finding suggests that the analyses of E1SO4 and PAGs could be used for monitoring foetal well-being in animals with a high risk of stillbirth at term. [less ▲]

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See detailUltrasonography in early pregnancy diagnosis and measurements of fetal size in reindeer (Rangifer tarandus tarandus)
Vahtiala, S.; Sakkinen, H.; Dahl, E. et al

in Theriogenology (2004), 61(4), 785-795

Transrectal or transabdominal examinations of 13 pluriparous reindeer (Rangifer tarandus tarandus) by ultrasonography from the start of mating until week 20 of gestation were conducted to find out when ... [more ▼]

Transrectal or transabdominal examinations of 13 pluriparous reindeer (Rangifer tarandus tarandus) by ultrasonography from the start of mating until week 20 of gestation were conducted to find out when pregnancy could first be detected and to describe fetal development in early pregnancy. The examinations (n = 35 per animal) were performed with a 5 MHz linear transducer from 7th October until 1st January and with a 3 MHz sector transducer from that time until 24th February. Time of pregnancy diagnosis by ultrasonography, the first fetal heartbeat and measurements of crown-rump length, chest width and chest depth were recorded during the examinations. Pregnancy was diagnosed by transrectal ultrasonography between the weeks 3 and 7 of gestation. The accuracy of the pregnancy diagnosis, defined as the proportion of females correctly detected to be pregnant, was 15% at week 3, 46% at week 4, 77% at week 5, and 92% at week 6 of gestation. Fetal heartbeat was first detected between the weeks 5 and 8 of gestation. The first measurements of crown-rump length were made on week 3 of gestation, of chest width on week 4 and of chest depth on week 5 of gestation. Chest width and depth were detectable until the end of the study at week 20 of gestation. Transrectal ultrasonography is an efficient tool in early pregnancy diagnosis of reindeer. The fetal growth curves obtained by ultrasonography resembled those obtained in previous morphological studies. [less ▲]

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See detailPAG profiles in postpartum dairy cows and newborn calves
Ropstad, E; Kalberg, K; Dahl, E et al

in Reproduction in Domestic Animals (2002), 37(4), 249

In ruminants, pregnancy associated glycoproteins (PAG), synthesized in the outer layers of the trophoblast, enter the maternal bloodstream. In this study, blood samples from cows in the postpartum period ... [more ▼]

In ruminants, pregnancy associated glycoproteins (PAG), synthesized in the outer layers of the trophoblast, enter the maternal bloodstream. In this study, blood samples from cows in the postpartum period, pregnant cows and calves were collected to determine 1) the clearance rate of PAG, 2) the accuracy of PAG measurements used for pregnancy diagnosis and 3) PAG concentrations and clearance rate in newborn calves. A curvilinear decline in PAG was found with increasing days from calving. Between day 70–80 pp 3 out of 11 samples (27%) had PAG concentrations > 4 ng/ml plasma. A cut-off value of 4 ng/ml was found to give the best accuracy for pregnancy diagnosis 28–36 days after service (n ¼58: sensitivity¼0.97; specificity ¼1.0). PAG concentrations in newborn calves (n¼10) varied between 78–880 ng/ml, declining with increasing age in a curvilinear pattern to < 1 ng/ml between 20–40 days pp. In two male twin calves PAG concentrations were 880 and 101 ng/ml, respectively, at one day of age. We conclude: 1) 4 ng PAG /ml provides the best cut-off value for pregnancy diagnosis. 2) Cows serviced before 60 days pp can produce false positive pregnancy diagnoses due to PAG originating from the previous pregnancy. 3) High PAG concentrations can be found in newborn calves. [less ▲]

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See detailMonitoring of foetal viability with endocrine parameters during late pregnancy and parturition in dairy cows
Kornmatitsuk, B.; Dahl, E.; Ropstad, E. et al

in Proceedings: 5th Conference of the European Society for Domestic Animal Reproduction (2001)

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