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Decamethylcyclopentasiloxane (D5) is used in personal care products and industrial applications. The authors summarize the risks to the environment from D5 based on multiple lines of evidence and conclude that it presents negligible risk. Laboratory and field studies show that D5 is not toxic to aquatic organisms or benthic invertebrates up to its solubility limit in water or porewater or its sorptive capacity in sediment. Comparison of lipid-normalized internal concentrations with measured concentrations in benthos indicates that field-collected organisms do not achieve toxic levels of D5 in their tissues, suggesting negligible risk. Exposure to D5 resulted in a slight reduction of root biomass in barley at test concentrations 2 orders of magnitude greater than measured D5 levels in biosolids-amended soils and more than twice as high as the maximum calculated sorptive capacity of the soil. No effects were observed in soil invertebrates exposed to similar concentrations, indicating that D5 poses a de minimis risk to the terrestrial environment. High rates of metabolism and elimination of D5 compared with uptake rates from food results in biodilution in the food web rather than biomagnification, culminating in de minimis risk to higher trophic level organisms via the food chain. A fugacity approach substantiates all conclusions that were made on a concentration basis

Amaç: Çalışmanın amaçları, holştayn ırkı ineklerin rasyonuna 90 gün boyunca zenginleştirilmiş balık yağı formunda uzun zincirli omega-3 çoklu doymamış balık yağı katılmasının veya ovulasyon günü ve 11 gün sonrasında iki kere inek somatotropin enjeksiyonunun endometriumunda PPAR ekspresyonu ve aktivasyonunu araştırmaktır. Gereç ve Yöntem: Laktasyonda olmayan inekler siklik, siklik-bST, gebe veya gebe-bST olmak üzere 4 gruba ayrıldı. Laktasyondaki inekler ise siklik, siklik-bST, gebe, gebe-bST, siklik-FO veya siklik-FO-bST olmak üzere 6 gruba ayrıldı.Bulgular: Northern ve Western blot analizleri PPARα ve PPARδ’nın ovulasyon sonrası 17. günde endometriumda ekspre edildiğini belirlendi ancak PPARγ tespit edilemedi. bST uygulaması sadece gebelerde PPARδ mRNA ekspresyonunu arttırdı, bu etki embriyo tarafından düzenlenmiş olabilir. Laktasyondaki gebe ineklerin endometriumundaki bST’ya bağlı PPARα mRNA miktarındaki artış bST etkisinin gebelik durumuna bağlı olduğunu vurgulamaktadır. Rasyona balık yağı eklenmesi PPARδ mRNA miktarını azaltırken, PPARα mRNA miktarı üzerine bir etkisi olmadı. PPARδ proteini luminal epitelde, glandular epitelde, subepitel stromada ve az miktarda da adluminal stromada belirlendi. Anti-PPARδ reaksiyonu bST uygulaması ve balık yağı beslemesine bağlı olarak gebe ineklerde azaldı. Öneri: bST uygulaması ve balık yağı beslemesi endometrialPPARα ve PPARδ ekspresyonun laktasyondaki sütçü ineklerde etkilemektedir., Aim: The study objectives were to determine whether dietary supplementation with long chain omega-3 polyunsaturated fatty acids in the form of enriched fish oil (FO) for 90 days or treatment with bovine somatotropin (bST) at the time of ovulation and 11 days post-ovulation influenced PPAR expression and activation in bovine endometrium in Holstein cows.Materials and Methods: Non-lactating cows were assigned to one of four treatments: cyclic, cyclic-bST, pregnant or pregnant-bST. Lactating cows were assigned to one of six treatments: cyclic, cyclic-bST, pregnant, pregnant-bST, cyclic-FO or cyclic-FO-bST.Results: Northern and Western blot analyses indicated that PPARα and PPARδ, but not PPARγ, are expressed in endometrium from all cows at day 17 post-ovulation. Treatment with bST is associated with increased PPARδ mRNA abundance in pregnant but not cyclic cows, suggesting that the effect may be mediated by the embryo. Increased abundances of PPARα mRNA are observed in response to bST during pregnancy in lactating cows but not in non-lactating cows, highlighting the importance of lactation status in determining bST response. Fish oil supplementation is associated with reduced PPARδ mRNA abundance, but did not affect steady-state PPARα mRNA abundance. PPARδ protein is expressed in the luminal epithelium, glandular epithelium, subepithelial stroma and to a lesser extent in the adluminal stroma. Anti-PPARδ reactivity is reduced in response to bST and fish oil treatments in pregnant cows.Conclusion: bST and fish oil treatments affect endometrial PPARα and PPARδ expression in lactating dairy cows.

The objectives of this study were to determine the association between mild fatty liver and -carotene (BC), retinol (ROL), and -tocopherol (AT) status. Multiparous Holstein cows were defined as having mild fatty liver using a threshold of 2% liver triacylglycerol (TAG, wet basis) at day (d) 2 after calving. Cows with mild fatty liver decreased dry matter intake (DMI) as a % of body weight (BW) from calving to 5th week (wk) of lactation (3.47 vs. 3.99, P = 0.02) and increased plasma nonesterified fatty acids (NEFA) concentration (345.0 vs. 266.0 µeq/dL, P = 0.10) as compared to normal cows. Fatty liver tended to lower plasma ROL (0.20 vs. 0.23 µg/mL, P = 0.10), but had no effect on plasma BC, plasma AT, liver BC, and liver ROL (P > 0.12) concentrations. However, depression in liver BC at calving was very small (8.0 vs. 68.0%) for fatty liver than for normal cows. Liver AT concentrations were greater (5.5 vs. 4.0 µg/g, P = 0.06) for cows with more than 2% liver TAG concentration. Concentration of plasma NEFA was positively correlated with plasma BC concentrations (r = 0.18, P < 0.05) and negatively correlated with concentrations of plasma ROL (r = -0.36, P < 0.0001) or AT (r = -0.35, P < 0.0001). A positive direct relationship between DMI and plasma vitamins status was found to exist only for ROL and AT, which suggests that stores of ROL or AT are less labile than stores for BC. At different times from calving, liver BC concentrations were positively correlated with liver TAG concentrations in a consistent manner but, correlations among liver ROL or liver AT concentrations and liver TAG concentrations were nonsignificants. The results suggest that the regulatory role of the liver in maintaining retinol concentrations in plasma may be compromise in cows with fatty liver. Este estudio fue realizado con los objetivos de determinar la asociación entre hígado graso leve (HGL) y estatus de -caroteno (BC), retinol (ROL) y -tocoferol (AT). Para definir HGL en vacas Holstein multíparas se empleó como valor crítico el 2% de triacilgliceroles (TAG, base fresca) en el hígado al segundo día después del parto. El consumo de materia seca (CMS), como porcentaje del peso vivo, disminuyó (3,47 vs. 3,99; P = 0,02) mientras que la concentración de ácidos grasos no-esterificados (AGNE) incrementó (345,0 vs. 266,0 µeq/dL; P = 0,10), desde el parto hasta la 5ta semana de lactancia en las vacas con HGL en comparación con las vacas control. El hígado graso tuvo la tendencia a disminuir el ROL plasmático (0,20 vs. 0,23 µg/mL, P = 0,10), pero no afectó las concentraciones de BC y AT en plasma, ni las de BC y ROL hepático (P > 0,12). Sin embargo, en el parto, la caída del BC hepático fue muy pequeña (8,0 vs. 68,0%) en las vacas con HGL. Las concentraciones de AT hepático fueron mayores (5,5 vs. 4,0 µg/g, P = 0,06) en las vacas con más de 2% de TAG hepático. La concentración plasmática de AGNE tuvo una correlación positiva con las concentraciones plasmáticas de BC (r = 0,18; P < 0,05) pero negativa con las concentraciones de ROL (r = -0,36: P < 0,0001) o AT (r = -0,35; P < 0,0001) plasmático. Solo el estatus plasmático de ROL y AT evidenciaron una relación directa positiva con el CMS, lo que sugiere que los depósitos de ROL o AT son menos lábiles que los de BC. En días diferentes del postparto, las concentraciones hepáticas de BC fueron correlacionadas positivamente con las concentraciones hepáticas de TAG de una manera consistente, pero las correlaciones entre las concentraciones de ROL o AT hepático vs. las de TAG hepático no fueron significativas. Los resultados sugieren que la función reguladora del hígado para mantener las concentraciones plasmáticas de retinol puede estar comprometida en las vacas que sufren hígado graso. 399 - 408 orosendo@ucla.edu.ve Bimestral

Este estudio fue realizado con los objetivos de determinar la asociación entre hígado graso leve (HGL) y estatus de β-caroteno (BC), retinol (ROL) y a-tocoferol (AT). Para definir HGL en vacas Holstein multíparas se empleó como valor crítico el 2% de triacilgliceroles (TAG, base fresca) en el hígado al segundo día después del parto. El consumo de materia seca (CMS), como porcentaje del peso vivo, disminuyó (3,47 vs. 3,99; P = 0,02) mientras que la concentración de ácidos grasos no-esterificados (AGNE) incrementó (345,0 vs. 266,0 µeq/dL; P = 0,10), desde el parto hasta la 5ta semana de lactancia en las vacas con HGL en comparación con las vacas control. El hígado graso tuvo la tendencia a disminuir el ROL plasmático (0,20 vs. 0,23 µg/mL, P = 0,10), pero no afectó las concentraciones de BC y AT en plasma, ni las de BC y ROL hepático (P > 0,12). Sin embargo, en el parto, la caída del BC hepático fue muy pequeña (8,0 vs. 68,0%) en las vacas con HGL. Las concentraciones de AT hepático fueron mayores (5,5 vs. 4,0 µg/g, P = 0,06) en las vacas con más de 2% de TAG hepático. La concentración plasmática de AGNE tuvo una correlación positiva con las concentraciones plasmáticas de BC (r = 0,18; P < 0,05) pero negativa con las concentraciones de ROL (r = -0,36: P < 0,0001) o AT (r = -0,35; P < 0,0001) plasmático. Solo el estatus plasmático de ROL y AT evidenciaron una relación directa positiva con el CMS, lo que sugiere que los depósitos de ROL o AT son menos lábiles que los de BC. En días diferentes del postparto, las concentraciones hepáticas de BC fueron correlacionadas positivamente con las concentraciones hepáticas de TAG de una manera consistente, pero las correlaciones entre las concentraciones de ROL o AT hepático vs. las de TAG hepático no fueron significativas. Los resultados sugieren que la función reguladora del hígado para mantener las concentraciones plasmáticas de retinol puede estar comprometida en las vacas que sufren hígado graso. The objectives of this study were to determine the association between mild fatty liver and β-carotene (BC), retinol (ROL), and a-tocopherol (AT) status. Multiparous Holstein cows were defined as having mild fatty liver using a threshold of 2% liver triacylglycerol (TAG, wet basis) at day (d) 2 after calving. Cows with mild fatty liver decreased dry matter intake (DMI) as a % of body weight (BW) from calving to 5th week (wk) of lactation (3.47 vs. 3.99, P = 0.02) and increased plasma nonesterified fatty acids (NEFA) concentration (345.0 vs. 266.0 µeq/dL, P = 0.10) as compared to normal cows. Fatty liver tended to lower plasma ROL (0.20 vs. 0.23 µg/mL, P = 0.10), but had no effect on plasma BC, plasma AT, liver BC, and liver ROL (P > 0.12) concentrations. However, depression in liver BC at calving was very small (8.0 vs. 68.0%) for fatty liver than for normal cows. Liver AT concentrations were greater (5.5 vs. 4.0 µg/g, P = 0.06) for cows with more than 2% liver TAG concentration. Concentration of plasma NEFA was positively correlated with plasma BC concentrations (r = 0.18, P < 0.05) and negatively correlated with concentrations of plasma ROL (r = -0.36, P < 0.0001) or AT (r = -0.35, P < 0.0001). A positive direct relationship between DMI and plasma vitamins status was found to exist only for ROL and AT, which suggests that stores of ROL or AT are less labile than stores for BC. At different times from calving, liver BC concentrations were positively correlated with liver TAG concentrations in a consistent manner but, correlations among liver ROL or liver AT concentrations and liver TAG concentrations were nonsignificants. The results suggest that the regulatory role of the liver in maintaining retinol concentrations in plasma may be compromise in cows with fatty liver.