The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform

Edward P. Kolodziej - One of the best experts on this subject based on the ideXlab platform.

  • sorption and transport of trenbolone and Altrenogest photoproducts in soil water systems
    Environmental Science: Processes & Impacts, 2019
    Co-Authors: David M. Cwiertny, Haoqi Zhao, Xingjian Yang, Edward P. Kolodziej
    Abstract:

    This study evaluated the sorption and transport potential of seven phototransformation products of 17α-trenbolone, 17β-trenbolone, trendione, and Altrenogest, along with the parent trienone steroids in batch and column soil–water systems. In batch systems, the target solutes exhibited linear isotherms, with values for sorption coefficients (log Koc) of parent steroids (2.46–2.76) higher than those for photoproducts (1.92–2.57). In column systems, the estimated retardation factors (Rsol) for parents (2.7–5.1) were ∼2–5 times higher than those for photoproducts (0.84–1.7). The log Koc (R2 = 0.75) and Rsol (R2 = 0.89–0.98) were well correlated with measured log Kow values, indicating that hydrophobic partitioning governed the soil–solute interaction of these biologically potent compounds in soil–water systems. These data indicated that photoproducts exhibited reduced sorption affinity and increased transport potential relative to more hydrophobic parent structures. In agroecosystems, traditional runoff management practices would be expected to exhibit reduced treatment effectiveness for photoproducts relative to the parent compounds of commonly used trienone steroids.

  • detection and quantification of metastable photoproducts of trenbolone and Altrenogest using liquid chromatography tandem mass spectrometry
    Journal of Chromatography A, 2019
    Co-Authors: Philip T. Kenyon, David M. Cwiertny, Haoqi Zhao, Xingjian Yang, Edward P. Kolodziej
    Abstract:

    Abstract Here, we developed a novel and sensitive method for the detection and quantification of metastable trenbolone and Altrenogest photoproducts in agricultural receiving waters based on solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC–MS/MS). Primary method analytes were seven cycloaddition or photohydration transformation products of 17α-trenbolone (17α-TBOH), 17β-trenbolone (17β-TBOH), trendione (TBO), and Altrenogest (ALT), which are key contributors to the fate and environmental risks of these steroidal pharmaceuticals. Because commercial analytical standards are not available, reference standards for photoproducts were generated from trenbolone or ALT with a solar simulator (˜6 h, >10 half-lives). Efficient detection of metastable photoproducts required cold and pH neutral conditions, rapid sample processing, minimal sample storage, and consideration of cationic artifacts. Method detection limits (MDLs) were 0.034-0.40 ng L−1 for parent compounds and 0.16–2.1 ng L−1 for photoproducts, sufficient for their detection in agroecosystems. Matrix suppression was observed and corrected by internal standards, and relative recovery rates were near 100% for all analytes except for 12-OH-17α-TBOH (˜75% recovery). Intra-day variation was

  • intramolecular 2 2 photocycloaddition of Altrenogest confirmation of product structure theoretical mechanistic insight and bioactivity assessment
    Journal of Organic Chemistry, 2019
    Co-Authors: Nicholas C Pflug, David M. Cwiertny, Edward P. Kolodziej, Kristopher Mcneill, Dalma Martinovicweigelt, Eric V Patterson, James B Gloer, Kristine H Wammer
    Abstract:

    While studying the environmental fate of potent endocrine-active steroid hormones, we observed the formation of an intramolecular [2 + 2] photocycloaddition product (2) with a novel hexacyclic ring system following the photolysis of Altrenogest (1). The structure and absolute configuration were established by X-ray diffraction analysis. Theoretical computations identified a barrierless two-step cyclization mechanism for the formation of 2 upon photoexcitation. 2 exhibited progesterone, estrogen, androgen, and pregnane X receptor activity, albeit generally with reduced potency relative to 1.

N M Soede - One of the best experts on this subject based on the ideXlab platform.

  • follicle size and reproductive hormone profiles during a post weaning Altrenogest treatment in primiparous sows
    Reproduction Fertility and Development, 2015
    Co-Authors: J J J Van Leeuwen, B Kemp, M R T M Martens, J Jourquin, M A Driancourt, A Wagner, N M Soede
    Abstract:

    This study investigated the endocrine background of follicle size changes during post-weaning Altrenogest treatment. Altrenogest-treated sows received a 20-mg dosage daily at 8.00 a.m. from Day -1 to Day 14 after weaning. On Day -1, only 3/13 Altrenogest-treated sows showed LH pulses compared with 8/8 control sows (P=0.001). On Day 0, control sows showed a typical high frequency-low amplitude LH pattern, indicative for recruitment of oestrogenic follicles. In Altrenogest-treated animals on Day 0, half of the sows showed high frequency-high amplitude pulses from 4-5h after weaning. In Altrenogest-treated sows, average follicle size increased from 3.1±0.5 mm on Day 0 to 4.4±0.6mm on Day 5, then decreased to 3.7±0.5 mm on Day 7 and stabilised thereafter. FSH and oestradiol (E2) concentrations showed a distinct diurnal pattern; high at 7.00 a.m. and low at 3.00 p.m. E2 concentrations (7.00 a.m.) showed a 2.5-fold increase from Day -1 to Day 2, and subsequently a 2-fold decline to reach a plateau at Day 8. FSH concentrations reached maximum levels by Day 5 and slowly declined afterwards. In conclusion, once-daily administration of Altrenogest starting one day before weaning delays the weaning-induced increase in LH pulses. Although FSH and follicle size increase until Day 5 after weaning, follicle E2 production already decreased from Day 2 after weaning. Post-weaning Altrenogest treatment thus results in a follicular wave of follicles that lose oestrogenic competence at Day 2 after weaning, presumably related to the changed LH dynamics during Altrenogest treatment.

  • progestagen supplementation during early pregnancy does not improve embryo survival in pigs
    Reproduction in Domestic Animals, 2012
    Co-Authors: N M Soede, E G Bouwman, P Langendijk, J Jourquin, I Van Der Laan, W Hazeleger, B Kemp
    Abstract:

    Progesterone supplementation during early pregnancy may increase embryo survival in pigs. The current study evaluated whether oral supplementation with an analogue of progesterone, Altrenogest (ALT), affects embryo survival. A first experiment evaluated the effect of a daily 20-mg dosage of ALT during days 1–4 or 2–4 after onset of oestrus on embryo survival at day 42 of pregnancy. A control group (CTR1) was not treated. The time of ovulation was estimated by transrectal ultrasound at 12-h intervals. Altrenogest treatment significantly reduced pregnancy rate when start of treatment was before or at ovulation: 25% (5/20) compared to later start of treatment [85% (28/33)] and non-treated CTR1 [100% (23/23)]. Altrenogest treatment also reduced (p <0.05) number of foetuses, from 14.6 ± 2.6 in CTR1 to 12.5 ± 2.5 when ALT started 1–1.5 days from ovulation and 10.7 ± 2.9 when ALT started 0–0.5 days from ovulation. In a second experiment, sows with a weaning-to-oestrous interval (WOI) of 6, 7 or 8–14 days were given ALT [either 20 mg (ALT20; n = 49) or 10 mg (ALT10; n = 48)] at day 4 and day 6 after onset of oestrus or were not treated (CTR2; n = 49), and farrowing rate and litter size were evaluated. Weaning-to-oestrous interval did not affect farrowing rate or litter size. ALT did not affect farrowing rate (86% vs 90% in CTR2), but ALT20 tended to have a lower litter size compared with CTR2 (11.7 ± 4.1 vs 13.3 ± 3.1; p = 0.07) and ALT10 was intermediate (12.3 ± 2.9). In conclusion, Altrenogest supplementation too soon after ovulation reduces fertilization rate and embryo survival rate and Altrenogest supplementation at 4–6 days of pregnancy reduces litter size. As a consequence, Altrenogest supplementation during early pregnancy may reduce both farrowing rate and litter size and cannot be applied at this stage in practice as a remedy against low litter size.

  • split weaning before Altrenogest synchronization of multiparous sows alters follicular development and reduces embryo survival
    Reproduction in Domestic Animals, 2012
    Co-Authors: J J J Van Leeuwen, B Kemp, M Verhoeven, I Van Der Hedenvan Noort, S Kranenbarg, N M Soede
    Abstract:

    This study used split-weaning (SW) to induce differences in follicle size at weaning and study its consequences for follicle development during and after post-weaning Altrenogest feeding and for reproductive performance. Multiparous sows (n = 47) were assigned to SW (n = 23; litter size reduced to the six smallest piglets 3 days before weaning) or control (C; n = 24; normal weaning). Altrenogest (20 mg/day) was fed to all 47 sows from Day -1 till Day 5 (complete weaning = Day 0). Follicle size on Day 1, 2 and 8 was smaller in C than in SW (p = 0.05). Ovulation rate was similar, but C sows had higher embryo survival rate (ESR) than SW sows (83 ± 19 and 58 ± 31%, respectively; p = 0.001). SW sows with low ESR (63%; n = 10; p = 0.04). A decrease in follicle size between Day 5 and 6 of Altrenogest feeding was associated with increased ESR in both treatments (p = 0.002). Follicle pool analyses (assessment of all follicles >2 mm) revealed that on Day 3, sows with low ESR had a higher % of follicles >5 mm compared with sows with high ESR (30% vs 10%; p = 0.04). Thus, sows in which follicle growth was less suppressed during Altrenogest feeding had a lower ESR. These effects on follicle development and ESR were more pronounced in split-weaned sows.

  • effects of Altrenogest treatments before and after weaning on follicular development farrowing rate and litter size in sows
    Journal of Animal Science, 2011
    Co-Authors: J J J Van Leeuwen, B Kemp, M R T M Martens, J Jourquin, M A Driancourt, N M Soede
    Abstract:

    In a previous study, we showed that follicle size at weaning affects a sow’s response to a short Altrenogest treatment after weaning. In this study, an attempt was made to prevent growth of follicles into larger size categories before weaning using different Altrenogest treatments before weaning to improve reproductive performance after postweaning Altrenogest treatments. Sows (87 primiparous and 130 multiparous) were assigned to: control (no Altrenogest treatment; n = 59), RU0-20 (20 mg Altrenogest, d -1 to d 6; weaning = d 0; n = 53), RU40-20 (40 mg Altrenogest, d -3 to d 0 and 20 mg Altrenogest d 1 to d 6; n = 53), and RU20-20 (20 mg Altrenogest, d -3 to d 6; n = 52). Follicle size was assessed daily with trans-abdominal ultrasound. Follicle size on d -3 (3.6 ± 0.7 mm) and at weaning (4.0 ± 0.7 mm) was similar for all treatments. Altrenogest-treated sows had larger follicles at the start of the follicular phase than control sows (5.4 ± 0.1 and 3.8 ± 0.2 mm, LS Means, respectively; P <0.0001) and on d 4 of the follicular phase (8.0 ± 0.1 and 6.7 ± 0.2 mm, LS Means, respectively; P <0.0001). Multiparous sows had larger follicles than primiparous sows at the start of the follicular phase (5.3 ± 0.1 and 4.7 ± 0.1 mm, LS Means, respectively; P <0.01) and on d 4 of the follicular phase (8.0 ± 0.1 and 7.0 ± 0.1 mm, LS Means, respectively; P <0.0001). Farrowing rate and litter size (born alive + dead) were not affected by treatment or parity. However, in primiparous sows, when mummies were included in litter size, Altrenogest sows had larger litters than control sows (13.4 ± 0.5 and 11.9 ± 0.7 piglets, respectively; P = 0.02). In primiparous control sows, backfat depth at weaning and litter size were positively related (slope of the regression line = 0.82; P <0.05), which was not the case in primiparous Altrenogest sows. In conclusion, the different Altrenogest treatments before weaning did not prevent growth of follicles before weaning and similarly affected subsequent follicle development and fertility. In primiparous sows, Altrenogest treatment after weaning increased the number of fetuses during pregnancy but positive effects seemed limited by uterine capacity. Altrenogest treatment after weaning improved litter size in primiparous sows with low backfat depth at weaning, which suggests a specific positive effect of a recovery period after weaning in sows with low body condition scores at weaning

  • variation in lh pulsatility during 24 h after a postweaning Altrenogest treatment in relation to follicle development in primiparous sows
    Animal Reproduction Science, 2011
    Co-Authors: J J J Van Leeuwen, B Kemp, M R T M Martens, J Jourquin, M A Driancourt, N M Soede
    Abstract:

    This study assessed pulsatile release of LH during Altrenogest treatment after weaning in primiparous sows and related this to follicle development, estrus and ovulation rate. Weaned sows (n=10) received Altrenogest 20mg/day from D-1 to D13 (weaning=D0) at 0800 h. On D13, blood samples were collected every 12 min from 1000 until 1900 h (1st sampling period) and from 2300 h until 0800 h (2nd sampling period). During the 1st sampling period, LH concentrations remained low and no LH pulses were detected in 8/10 sows. During the 2nd sampling period, average and basal LH concentrations (P<0.04) and frequency of pulses (P<0.0001) were higher than during the 1st sampling period. Sows with short vs. long intervals to estrus (<5 days vs. ≥5 days) had higher basal and average LH concentrations during the 2nd sampling period (P≤0.004) and showed more follicular growth during treatment (P=0.007), generating larger follicles at D14 (P=0.005). Sows with high ovulation rate (≥25) displayed more LH pulses in total than sows with low (<25) ovulation rates (P=0.03). In conclusion, this study showed that Altrenogest efficiently prevented LH pulsatility during the first bleeding period and that low frequency/high amplitude LH pulses were generally present during the second bleeding period. This variability in LH release in between two Altrenogest administrations (24h) may explain why follicular growth progresses to 5mm during Altrenogest treatments. LH pulsatility was related to length of the follicular phase and ovulation rate, which signifies its relevance.

Xingjian Yang - One of the best experts on this subject based on the ideXlab platform.

  • sorption and transport of trenbolone and Altrenogest photoproducts in soil water systems
    Environmental Science: Processes & Impacts, 2019
    Co-Authors: David M. Cwiertny, Haoqi Zhao, Xingjian Yang, Edward P. Kolodziej
    Abstract:

    This study evaluated the sorption and transport potential of seven phototransformation products of 17α-trenbolone, 17β-trenbolone, trendione, and Altrenogest, along with the parent trienone steroids in batch and column soil–water systems. In batch systems, the target solutes exhibited linear isotherms, with values for sorption coefficients (log Koc) of parent steroids (2.46–2.76) higher than those for photoproducts (1.92–2.57). In column systems, the estimated retardation factors (Rsol) for parents (2.7–5.1) were ∼2–5 times higher than those for photoproducts (0.84–1.7). The log Koc (R2 = 0.75) and Rsol (R2 = 0.89–0.98) were well correlated with measured log Kow values, indicating that hydrophobic partitioning governed the soil–solute interaction of these biologically potent compounds in soil–water systems. These data indicated that photoproducts exhibited reduced sorption affinity and increased transport potential relative to more hydrophobic parent structures. In agroecosystems, traditional runoff management practices would be expected to exhibit reduced treatment effectiveness for photoproducts relative to the parent compounds of commonly used trienone steroids.

  • detection and quantification of metastable photoproducts of trenbolone and Altrenogest using liquid chromatography tandem mass spectrometry
    Journal of Chromatography A, 2019
    Co-Authors: Philip T. Kenyon, David M. Cwiertny, Haoqi Zhao, Xingjian Yang, Edward P. Kolodziej
    Abstract:

    Abstract Here, we developed a novel and sensitive method for the detection and quantification of metastable trenbolone and Altrenogest photoproducts in agricultural receiving waters based on solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC–MS/MS). Primary method analytes were seven cycloaddition or photohydration transformation products of 17α-trenbolone (17α-TBOH), 17β-trenbolone (17β-TBOH), trendione (TBO), and Altrenogest (ALT), which are key contributors to the fate and environmental risks of these steroidal pharmaceuticals. Because commercial analytical standards are not available, reference standards for photoproducts were generated from trenbolone or ALT with a solar simulator (˜6 h, >10 half-lives). Efficient detection of metastable photoproducts required cold and pH neutral conditions, rapid sample processing, minimal sample storage, and consideration of cationic artifacts. Method detection limits (MDLs) were 0.034-0.40 ng L−1 for parent compounds and 0.16–2.1 ng L−1 for photoproducts, sufficient for their detection in agroecosystems. Matrix suppression was observed and corrected by internal standards, and relative recovery rates were near 100% for all analytes except for 12-OH-17α-TBOH (˜75% recovery). Intra-day variation was

J J J Van Leeuwen - One of the best experts on this subject based on the ideXlab platform.

  • follicle size and reproductive hormone profiles during a post weaning Altrenogest treatment in primiparous sows
    Reproduction Fertility and Development, 2015
    Co-Authors: J J J Van Leeuwen, B Kemp, M R T M Martens, J Jourquin, M A Driancourt, A Wagner, N M Soede
    Abstract:

    This study investigated the endocrine background of follicle size changes during post-weaning Altrenogest treatment. Altrenogest-treated sows received a 20-mg dosage daily at 8.00 a.m. from Day -1 to Day 14 after weaning. On Day -1, only 3/13 Altrenogest-treated sows showed LH pulses compared with 8/8 control sows (P=0.001). On Day 0, control sows showed a typical high frequency-low amplitude LH pattern, indicative for recruitment of oestrogenic follicles. In Altrenogest-treated animals on Day 0, half of the sows showed high frequency-high amplitude pulses from 4-5h after weaning. In Altrenogest-treated sows, average follicle size increased from 3.1±0.5 mm on Day 0 to 4.4±0.6mm on Day 5, then decreased to 3.7±0.5 mm on Day 7 and stabilised thereafter. FSH and oestradiol (E2) concentrations showed a distinct diurnal pattern; high at 7.00 a.m. and low at 3.00 p.m. E2 concentrations (7.00 a.m.) showed a 2.5-fold increase from Day -1 to Day 2, and subsequently a 2-fold decline to reach a plateau at Day 8. FSH concentrations reached maximum levels by Day 5 and slowly declined afterwards. In conclusion, once-daily administration of Altrenogest starting one day before weaning delays the weaning-induced increase in LH pulses. Although FSH and follicle size increase until Day 5 after weaning, follicle E2 production already decreased from Day 2 after weaning. Post-weaning Altrenogest treatment thus results in a follicular wave of follicles that lose oestrogenic competence at Day 2 after weaning, presumably related to the changed LH dynamics during Altrenogest treatment.

  • split weaning before Altrenogest synchronization of multiparous sows alters follicular development and reduces embryo survival
    Reproduction in Domestic Animals, 2012
    Co-Authors: J J J Van Leeuwen, B Kemp, M Verhoeven, I Van Der Hedenvan Noort, S Kranenbarg, N M Soede
    Abstract:

    This study used split-weaning (SW) to induce differences in follicle size at weaning and study its consequences for follicle development during and after post-weaning Altrenogest feeding and for reproductive performance. Multiparous sows (n = 47) were assigned to SW (n = 23; litter size reduced to the six smallest piglets 3 days before weaning) or control (C; n = 24; normal weaning). Altrenogest (20 mg/day) was fed to all 47 sows from Day -1 till Day 5 (complete weaning = Day 0). Follicle size on Day 1, 2 and 8 was smaller in C than in SW (p = 0.05). Ovulation rate was similar, but C sows had higher embryo survival rate (ESR) than SW sows (83 ± 19 and 58 ± 31%, respectively; p = 0.001). SW sows with low ESR (63%; n = 10; p = 0.04). A decrease in follicle size between Day 5 and 6 of Altrenogest feeding was associated with increased ESR in both treatments (p = 0.002). Follicle pool analyses (assessment of all follicles >2 mm) revealed that on Day 3, sows with low ESR had a higher % of follicles >5 mm compared with sows with high ESR (30% vs 10%; p = 0.04). Thus, sows in which follicle growth was less suppressed during Altrenogest feeding had a lower ESR. These effects on follicle development and ESR were more pronounced in split-weaned sows.

  • effects of Altrenogest treatments before and after weaning on follicular development farrowing rate and litter size in sows
    Journal of Animal Science, 2011
    Co-Authors: J J J Van Leeuwen, B Kemp, M R T M Martens, J Jourquin, M A Driancourt, N M Soede
    Abstract:

    In a previous study, we showed that follicle size at weaning affects a sow’s response to a short Altrenogest treatment after weaning. In this study, an attempt was made to prevent growth of follicles into larger size categories before weaning using different Altrenogest treatments before weaning to improve reproductive performance after postweaning Altrenogest treatments. Sows (87 primiparous and 130 multiparous) were assigned to: control (no Altrenogest treatment; n = 59), RU0-20 (20 mg Altrenogest, d -1 to d 6; weaning = d 0; n = 53), RU40-20 (40 mg Altrenogest, d -3 to d 0 and 20 mg Altrenogest d 1 to d 6; n = 53), and RU20-20 (20 mg Altrenogest, d -3 to d 6; n = 52). Follicle size was assessed daily with trans-abdominal ultrasound. Follicle size on d -3 (3.6 ± 0.7 mm) and at weaning (4.0 ± 0.7 mm) was similar for all treatments. Altrenogest-treated sows had larger follicles at the start of the follicular phase than control sows (5.4 ± 0.1 and 3.8 ± 0.2 mm, LS Means, respectively; P <0.0001) and on d 4 of the follicular phase (8.0 ± 0.1 and 6.7 ± 0.2 mm, LS Means, respectively; P <0.0001). Multiparous sows had larger follicles than primiparous sows at the start of the follicular phase (5.3 ± 0.1 and 4.7 ± 0.1 mm, LS Means, respectively; P <0.01) and on d 4 of the follicular phase (8.0 ± 0.1 and 7.0 ± 0.1 mm, LS Means, respectively; P <0.0001). Farrowing rate and litter size (born alive + dead) were not affected by treatment or parity. However, in primiparous sows, when mummies were included in litter size, Altrenogest sows had larger litters than control sows (13.4 ± 0.5 and 11.9 ± 0.7 piglets, respectively; P = 0.02). In primiparous control sows, backfat depth at weaning and litter size were positively related (slope of the regression line = 0.82; P <0.05), which was not the case in primiparous Altrenogest sows. In conclusion, the different Altrenogest treatments before weaning did not prevent growth of follicles before weaning and similarly affected subsequent follicle development and fertility. In primiparous sows, Altrenogest treatment after weaning increased the number of fetuses during pregnancy but positive effects seemed limited by uterine capacity. Altrenogest treatment after weaning improved litter size in primiparous sows with low backfat depth at weaning, which suggests a specific positive effect of a recovery period after weaning in sows with low body condition scores at weaning

  • variation in lh pulsatility during 24 h after a postweaning Altrenogest treatment in relation to follicle development in primiparous sows
    Animal Reproduction Science, 2011
    Co-Authors: J J J Van Leeuwen, B Kemp, M R T M Martens, J Jourquin, M A Driancourt, N M Soede
    Abstract:

    This study assessed pulsatile release of LH during Altrenogest treatment after weaning in primiparous sows and related this to follicle development, estrus and ovulation rate. Weaned sows (n=10) received Altrenogest 20mg/day from D-1 to D13 (weaning=D0) at 0800 h. On D13, blood samples were collected every 12 min from 1000 until 1900 h (1st sampling period) and from 2300 h until 0800 h (2nd sampling period). During the 1st sampling period, LH concentrations remained low and no LH pulses were detected in 8/10 sows. During the 2nd sampling period, average and basal LH concentrations (P<0.04) and frequency of pulses (P<0.0001) were higher than during the 1st sampling period. Sows with short vs. long intervals to estrus (<5 days vs. ≥5 days) had higher basal and average LH concentrations during the 2nd sampling period (P≤0.004) and showed more follicular growth during treatment (P=0.007), generating larger follicles at D14 (P=0.005). Sows with high ovulation rate (≥25) displayed more LH pulses in total than sows with low (<25) ovulation rates (P=0.03). In conclusion, this study showed that Altrenogest efficiently prevented LH pulsatility during the first bleeding period and that low frequency/high amplitude LH pulses were generally present during the second bleeding period. This variability in LH release in between two Altrenogest administrations (24h) may explain why follicular growth progresses to 5mm during Altrenogest treatments. LH pulsatility was related to length of the follicular phase and ovulation rate, which signifies its relevance.

  • the effect of different postweaning Altrenogest treatments of primiparous sows on follicular development pregnancy rates and litter sizes
    Journal of Animal Science, 2011
    Co-Authors: J J J Van Leeuwen, B Kemp, M R T M Martens, J Jourquin, M A Driancourt, S Williams, N M Soede
    Abstract:

    This study investigated follicular development during and after postweaning Altrenogest treatment of primiparous sows in relation to subsequent reproductive performance. Primiparous sows (n = 259) were randomly assigned at weaning (d 0) to 1 of 4 groups: control (no Altrenogest, n = 71), RU4 (20 mg of Altrenogest from d –1 to 2, n = 62), RU8 (20 mg of Altrenogest from d –1 to 6, n = 65), or RU15 (20 mg of Altrenogest from d –1 to 13, n = 61). Average follicular size (measured by ultrasound) increased during Altrenogest treatment and resulted in larger follicles at the start of the follicular phase for RU4, RU8, and RU15 compared with controls (5.3 ± 0.9, 5.5 ± 1.3, 5.1 ± 1.2, and 3.4 ± 0.6 mm, respectively; P <0.0001). Farrowing rate was greater in RU15 (95%) than in RU8 (76%; P = 0.04). The RU15 group also had more piglets (2 to 3 more piglets total born and born alive; P <0.05) than the other treatment groups. Follicular development at weaning clearly affected reproductive performance. At weaning, average follicular size: small (

David M. Cwiertny - One of the best experts on this subject based on the ideXlab platform.

  • sorption and transport of trenbolone and Altrenogest photoproducts in soil water systems
    Environmental Science: Processes & Impacts, 2019
    Co-Authors: David M. Cwiertny, Haoqi Zhao, Xingjian Yang, Edward P. Kolodziej
    Abstract:

    This study evaluated the sorption and transport potential of seven phototransformation products of 17α-trenbolone, 17β-trenbolone, trendione, and Altrenogest, along with the parent trienone steroids in batch and column soil–water systems. In batch systems, the target solutes exhibited linear isotherms, with values for sorption coefficients (log Koc) of parent steroids (2.46–2.76) higher than those for photoproducts (1.92–2.57). In column systems, the estimated retardation factors (Rsol) for parents (2.7–5.1) were ∼2–5 times higher than those for photoproducts (0.84–1.7). The log Koc (R2 = 0.75) and Rsol (R2 = 0.89–0.98) were well correlated with measured log Kow values, indicating that hydrophobic partitioning governed the soil–solute interaction of these biologically potent compounds in soil–water systems. These data indicated that photoproducts exhibited reduced sorption affinity and increased transport potential relative to more hydrophobic parent structures. In agroecosystems, traditional runoff management practices would be expected to exhibit reduced treatment effectiveness for photoproducts relative to the parent compounds of commonly used trienone steroids.

  • detection and quantification of metastable photoproducts of trenbolone and Altrenogest using liquid chromatography tandem mass spectrometry
    Journal of Chromatography A, 2019
    Co-Authors: Philip T. Kenyon, David M. Cwiertny, Haoqi Zhao, Xingjian Yang, Edward P. Kolodziej
    Abstract:

    Abstract Here, we developed a novel and sensitive method for the detection and quantification of metastable trenbolone and Altrenogest photoproducts in agricultural receiving waters based on solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC–MS/MS). Primary method analytes were seven cycloaddition or photohydration transformation products of 17α-trenbolone (17α-TBOH), 17β-trenbolone (17β-TBOH), trendione (TBO), and Altrenogest (ALT), which are key contributors to the fate and environmental risks of these steroidal pharmaceuticals. Because commercial analytical standards are not available, reference standards for photoproducts were generated from trenbolone or ALT with a solar simulator (˜6 h, >10 half-lives). Efficient detection of metastable photoproducts required cold and pH neutral conditions, rapid sample processing, minimal sample storage, and consideration of cationic artifacts. Method detection limits (MDLs) were 0.034-0.40 ng L−1 for parent compounds and 0.16–2.1 ng L−1 for photoproducts, sufficient for their detection in agroecosystems. Matrix suppression was observed and corrected by internal standards, and relative recovery rates were near 100% for all analytes except for 12-OH-17α-TBOH (˜75% recovery). Intra-day variation was

  • intramolecular 2 2 photocycloaddition of Altrenogest confirmation of product structure theoretical mechanistic insight and bioactivity assessment
    Journal of Organic Chemistry, 2019
    Co-Authors: Nicholas C Pflug, David M. Cwiertny, Edward P. Kolodziej, Kristopher Mcneill, Dalma Martinovicweigelt, Eric V Patterson, James B Gloer, Kristine H Wammer
    Abstract:

    While studying the environmental fate of potent endocrine-active steroid hormones, we observed the formation of an intramolecular [2 + 2] photocycloaddition product (2) with a novel hexacyclic ring system following the photolysis of Altrenogest (1). The structure and absolute configuration were established by X-ray diffraction analysis. Theoretical computations identified a barrierless two-step cyclization mechanism for the formation of 2 upon photoexcitation. 2 exhibited progesterone, estrogen, androgen, and pregnane X receptor activity, albeit generally with reduced potency relative to 1.