The effect of tributyrin supplementation to milk replacer on plasma glucagon-like peptide 2 concentrations in pre-weaning calves.

The objective of this study was to evaluate the effect of tributyrin (TB) supplementation to milk replacer (MR) on performance, health, and blood concentrations of metabolite and glucagon-like peptide (GLP-2) in pre-weaning calves. Twenty Holstein heifer calves were raised on an intensified nursing program using MR supplemented with either palm oil (CON) or TB (TB) at 0.3% (as fed basis) for 7 weeks starting 1 week after birth. Calves were fed a calf starter and kleingrass from the beginning of the study. Blood samples were obtained weekly to measure blood glucose, serum ß-hydroxybutyric acid (BHBA), insulin-like growth factor 1 (IGF-1), and plasma GLP-2 concentrations. Starter DMI and metabolizable energy (ME) intake were lower in TB calves at 46, 47, from 49 to 55 days after birth compared with the CON calves. However, any growth parameters were not affected by TB treatment. Blood glucose, serum BHBA, and IGF-1 concentrations were not affected by TB supplementation. On the other hand, mean plasma GLP-2 concentration among whole experimental period was higher for TB (0.60 ng/ml) compared with CON (0.41 ng/ml). In conclusion, feeding MR supplemented with TB increases plasma GLP-2 concentration, which might counterbalance the growth performance of TB calves despite the decreased ME intake.

Novel generation of deep eutectic solvent as an acceptor phase in three-phase hollow fiber liquid phase microextraction for extraction and preconcentration of steroidal hormones from biological fluids.

In this study, a novel generation of deep eutectic solvents (DESs) was used as an acceptor phase in three-phase hollow fiber liquid phase microextraction (HF-LPME) based on two immiscible organic phases. It was compared with other common DESs for extraction and preconcentration of dydrogesterone (DYD) and cyproterone acetate (CPA) from urine and plasma samples. The extracted analytes were analyzed by high performance liquid chromatography with UV-vis detector (HPLC-UV). This phosphonium based DES due to low volatility, low price and multifunctionality introduced itself as worthy next generation of acceptor phase in HF-LPME. The factors affected on extraction efficiency of the analytes were investigated and optimized. The performance of the proposed method was studied in terms of linear ranges (LRs from 1 to 500µgL-1 with R2 ≥ 0.9946), precision (RSD% ≤ 6.3) and limits of detection (LODs in the range of 0.5-2µgL-1). Under the optimized conditions, preconcentration factors in the range of 187-428 were obtained. Finally, the method was applied to the analysis of DYD and CPA in human urine and plasma samples and desirable results were obtained.

Tacrolimus Metabolite M-III May Have Nephrotoxic and Myelotoxic Effects and Increase the Incidence of Infections in Kidney Transplant Recipients.

BACKGROUND: Tacrolimus (Tac) is one of the most commonly used immunosuppressive drugs after solid organ transplantation. Eight Tac metabolites have been described, but their clinical importance remains unclear. The aim of this study was quantification of the 2 major Tac metabolites, 13-O-demethyl (M-I) and 15-O-demethyl (M-III), in kidney transplant recipients and to link them with parameters of kidney and liver function, peripheral blood cell counts, and infection incidence. METHODS: In 81 kidney transplant recipients, concentrations of Tac, M-I, and M-III were measured with the use of liquid chromatography combined with tandem mass spectrometry (LC-MS-MS). RESULTS: There was a negative correlation between M-III levels and estimated glomerular filtration rate (eGFR; r = -0.244; P < .05). Also, a negative correlation between M-III concentrations and red blood cell count (RBC) was found (r = -0.349; P < .05). Neither concentrations of Tac nor of M-I correlated with eGFR or RBC. M-I, M-III, and Tac were not related to alanine aminotransferase activity. Significantly higher Tac and M-III concentrations in the group with all types of infections in comparison with the group without infections were observed (6.95 ± 2.09 ng/mL vs 5.73 ± 2.43 ng/mL [P = .03] and 0.27 ± 0.17 ng/mL vs 0.20 ± 0.11 ng/mL [P = .04], respectively). CONCLUSIONS: The results suggest that higher concentrations of M-III may have a nephrotoxic or myelotoxic effect and result in higher incidence of infections. Further studies are needed to confirm if monitoring of M-III could minimalize adverse effects such as nephrotoxicity or infections.

Is maternal progesterone actually independent of the fetal steroids?

Progesterone and estradiol are the foremost steroid hormones in human pregnancy. However, the origin of maternal progesterone has still not been satisfactorily explained, despite the generally accepted opinion that maternal LDL-cholesterol is a single substrate for placental synthesis of maternal progesterone. The question remains why the levels of progesterone are substantially higher in fetal as opposed to maternal blood. Hence, the role of the fetal zone of fetal adrenal (FZFA) in the synthesis of progesterone precursors was addressed. The FZFA may be directly regulated by placental CRH inducing an excessive production of sulfated 3beta-hydroxy-5-ene steroids such as sulfates of dehydroepiandrosterone (DHEAS) and pregnenolone (PregS). Due to their excellent solubility in plasma these conjugates are easily transported in excessive amounts to the placenta for further conversion to the sex hormones. While the significance of C19 3beta-hydroxy-5-ene steroid sulfates originating in FZFA for placental estrogen formation is mostly recognized, the question "Which maternal and/or fetal functions may be served by excessive production of PregS in the FZFA?" - still remains open. Our hypothesis is that, besides the necessity to synthesize de novo all the maternal progesterone from cholesterol, it may be more convenient to utilize the fetal PregS. The activities of sulfatase and 3beta-hydroxysteroid dehydrogenase (3beta-HSD) are substantially higher than the activity of cytochrome P450scc, which is rate-limiting for the placental progesterone synthesis from LDL-cholesterol. However, as in the case of progesterone synthesis from maternal LDL-cholesterol, the relative independence of progesterone levels on FZFA activity may be a consequence of substrate saturation of enzymes converting PregS to progesterone. Some of the literature along with our current data (showing no correlation between fetal and maternal progesterone but significant partial correlations between fetal and maternal 20alpha-dihydroprogesterone (Prog20alpha) and between Prog20alpha and progesterone within the maternal blood) indicate that the localization of individual types of 17beta-hydroxysteroid dehydrogenase is responsible for a higher proportion of estrone and progesterone in the fetus, but also a higher proportion of estradiol and Prog20alpha in maternal blood. Type 2 17beta-hydroxysteroid dehydrogenase (17HSD2), which oxidizes estradiol to estrone and Prog20alpha to progesterone, is highly expressed in placental endothelial cells lining the fetal compartment. Alternatively, syncytium, which is directly in contact with maternal blood, produces high amounts of estradiol and Prog20alpha due to the effects of type 1, 5 and 7 17?-hydroxysteroid dehydrogenases (17HSD1, 17HSD5, and 17HSD7, respectively). The proposed mechanisms may serve the following functions: 1) providing substances which may influence the placental production of progesterone and synthesis of neuroprotective steroids in the fetus; and 2) creating hormonal milieu enabling control of the onset of labor.

New method for determination of dydrogesterone in human plasma for therapeutic drug monitoring in gynecological disorders.

UNLABELLED: A new simple, sensitive and selective liquid chromatography coupled with mass spectrometry (LC/MS) method for quantification of dydrogesterone in human plasma was validated. MATERIAL AND METHOD: The analytes was eluted in 1.3 minutes on a reversed phase column (Zorbax SB-C18, 100 mm x 3.0 mm I.D., 3.5 microm) under isocratic conditions using a mobile phase of a 20 : 80 (v/v) mixture of ammonium acetate 1 mM and acetonitrile. The flow rate was 1 mL/min at the column temperature of 35 degrees C. The detection of the analyte was in MS/ MS mode using an atmospheric pressure chemical ionization source (APCI+, m/z 313 > m/z 295). The sample preparation was very simple and rapid and consisted in plasma protein precipitation from 0.2 mL plasma using 0.6 mL methanol. RESULTS: Calibration curves were generated over the range of 5-150 ng/mL with values for coefficient of determination greater than 0.997 and by using a weighted (1/y) linear regression. The values of precision and accuracy were less than 12.5% and 7.5%, respectively, both for within- and between-run analysis. The mean recovery of the analyte was 99.8%. This is the first reported method for analysis dydrogesterone in human plasma that uses protein precipitation as sample processing procedure. The validated LC/MS method could be applied for determination of dydrogesterone in human plasma for therapeutic drug monitoring in gynecological disorders.

Relationship of estradiol levels to breakthrough bleeding during continuous combined hormone replacement therapy.

OBJECTIVE: To determine whether serum estradiol and dydrogesterone concentrations are associated with the occurrence of breakthrough bleeding. METHODS: In a prospective, double-blind study, 194 postmenopausal women were allocated randomly to receive one of four doses of dydrogesterone (2.5 mg, 5 mg, 10 mg, 15 mg) continuously combined with 2 mg of micronized 17beta-estradiol. All medication was taken orally for a total of 168 days. Vaginal bleeding was recorded on a daily basis. Serum estradiol (E2) and dihydrodydrogesterone (the main metabolite of dydrogesterone) trough levels were measured at day 85 and at the end of the study (day 168). Bleeding pattern analysis was done according to the reference period method. RESULTS: One hundred fifty-two of 177 women who completed the study supplied valid data on drug compliance, smoking habits, bleeding episodes, and serum hormone concentrations, which were used to assess the impact of serum E2 and dihydrodydrogesterone concentrations on the occurrence of breakthrough bleeding. Logistic regression analysis identified only the serum E2 concentration as having an independent, statistically significant effect (P = .003) on the occurrence of breakthrough bleeding; no such effect was associated with dihydrodydrogesterone levels (P = .118). The relative risk for the occurrence of breakthrough bleeding was 2.7 (95% confidence interval [CI] 1.454, 5.609) for serum E2 concentrations greater than 40 pg/mL. CONCLUSION: The occurrence of breakthrough bleeding during continuous combined hormone replacement therapy with estradiol and dydrogesterone in postmenopausal women was related to serum estradiol levels and not to dydrogesterone levels. Further studies are needed to test the hypothesis that estrogen is a major factor in the incidence of bleeding during postmenopausal hormone replacement therapy.

The effect of dydrogesterone on premenstrual symptoms. A double-blind, randomized, placebo-controlled study in general practice.

The effect of dydrogesterone on premenstrual symptoms was investigated in a double-blind, randomized, placebo-controlled study comprising 161 patients from unselected practice material. Dydrogesterone 10 mg twice daily from the 12th day until onset of the following menstrual period was compared with placebo throughout 3 cycles. No clinically relevant effect of dydrogesterone was found. There was an overall therapeutic effect in 52% of the patients on dydrogesterone, and in 44% of the placebo-treated patients. Therapeutic gain ranged between -7 and +23% (95% confidence limits). Type II error risk of failure to detect a therapeutic gain of 20% was 6%. A significant effect of dydrogesterone was found on decreased libido, and statistical significance was nearly achieved for the symptoms irritability and headache. The significant effect on libido can be attributed to mass significance.

Determination of 20 alpha-hydroxy-9 beta,10 alpha-pregna-4,6-dien-3-one in plasma by selected ion monitoring.

A selected ion monitoring (SIM) method has been devised for the determination of metabolites of dydrogesterone, 20 alpha-hydroxy-9 beta,10 alpha-pregna-4,6-dien-3-one (DHD) and DHD glucuronide, in plasma. Using testosterone as an internal standard (IS), DHD and IS were extracted with n-hexane and were purified by means of magnesium oxide column chromatography. The purified DHD and IS were converted to their diheptafluorobutyryl derivatives (DHD diHFB and testosterone diHFB) with heptafluorobutyric anhydride in acetone for analysis by SIM. SIM was carried out with a 2% OV-17 column (1 m) at 230 degrees C by monitoring the molecular ions of the derivatives (m/z 706 for DHD diHFB, m/z 680 for testosterone diHFB). DHD was determined from a calibration curve using a peak area method. The determination limit of the devised method was about 5 ng DHD per ml of plasma and the reproducibility was within +/- 6% of the coefficient of variation for 30 ng of DHD per ml of plasma or above.