No abstract

Fentanyl is the prototype of the 4-anilidopiperidine class of synthetic opioid analgesics. This study was aimed to review the structure-activity-relationship (SAR) of fentanyl analogs substituted in the position 3, or 4 of the piperidine ring. Pharmacological results show that the groups in position 3 of the piperidine ring, which are larger than methyl, severely reduce the analgesic potency compared to fentanyl. It is likely that the steric factor alone (i.e. voluminosity of the group and cis/trans isomerism), rather than the polarity and/or chemical reactivity, plays a crucial role in the analgesic potency of this series. Although the duration of action, in general, does not depend on the stereochemistry, longer action of the most potent 3-alkyl fentanyl analogs such as cis-3-methyl- and cis-3-ethyl fentanyl, is more likely influenced by pharmacodynamic, rather than pharmacokinetic variables. Also, it is possible that the introduction of a functional group such as 3-carbomethoxy reduces the duration of action by altering pharmacokinetic properties. SAR findings obtained by evaluating the neurotoxic effects of fentanyl analogs substituted in the position 3 of the piperidine ring parallel the SAR findings on analgesia in regard to potency and duration of action. This might suggest that similar receptors are involved in producing both antinociceptive and neurotoxic effects of these drugs. It appears that both the potency and the duration of action in the series of fentanyl analogs substituted in position 4 of the piperidine ring is influenced only by the steric requirement and not by the chemical nature of the substituent.

Pregnancy is associated with alterations in low-density lipoprotein (LDL) and high-density lipoprotein (HDL) subclasses, but the exact pattern of these variations remains controversial. This study investigates longitudinal changes of plasma LDL and HDL particles distributions during the course of normal pregnancy, as well as associations of maternal LDL and HDL subclasses distributions before delivery with parameters of newborn size. Blood samples were collected from 41 healthy pregnant women throughout entire pregnancy, before delivery and 7 weeks postpartum. LDL and HDL subclasses were determined by gradient gel electrophoresis, while other biochemical parameters were measured by standard laboratory methods. During gestation LDL size significantly decreased (P < 0.001), due to reduction in relative proportion of LDL I (P < 0.01) and increase of LDL II (P < 0.001) and IIIA (P < 0.05) subclasses. In the same time, HDL size and proportions of HDL 2a particles significantly decreased (P < 0.001), with concomitant increase of HDL 3b and 3c subclasses (P < 0.05). Observed alterations were associated with changes in serum triglyceride levels. Rearrangement in LDL subclasses distribution during gestation was transient, while postpartum HDL subclasses distribution remained shifted toward smaller particles. Higher proportion of LDL IVB in maternal plasma before delivery was an independent predictor of smaller birth weights and lengths, while higher proportions of LDL IVB and HDL 2a subclasses were independent determinants of newborns' smaller head circumferences. Routine gestational and prenatal care in otherwise normal pregnancy could be complemented with evaluation of LDL and HDL particles distribution in order to ensure an adequate size of the newborn.

The addition of secondary ultrasound markers (NB, DV and TR) to combined first-trimester screening showed a tendency toward improved accuracy of the screening.

Backgound/Aims: Existing data regarding the prevalence of thrombophilia in women with pregnancy complications are conflicting. Methods: To investigate the relationship between pregnancy-associated complications and the presence of thrombophilia, we studied the records of 453 women with pregnancy-associated complications. In 55 women, intrauterine fetal death (fetus mortus in utero, FMU) after 20 weeks of gestation was recorded, in 231 two or more consecutive recurrent fetal losses (RFL) were recorded, while 167 had a venous thromboembolism (VTE) during one of their pregnancies. The control group consisted of 128 healthy women, with no previous history of thrombotic events or miscarriages. Results: In the FMU group we found 54.5% of women had thrombophilia, in the RFL group 38%, and in the VTE group 52.7%. The most frequent thrombophilia in the VTE group was the FV Leiden (OR 17.9, 95% CI 4.2–75.9). The most frequent thrombophilia in the FMU group was the FII G20210A (OR 7.09, 95% CI 1.8–27.9). Statistical difference between RFL and the control group was observed only for FV Leiden (OR 6.8, 95% CI 1.6–29.7). Conclusion: Thrombophilia was found to be considerably more common in women with pregnancy-associated complications in comparison with the women with normal pregnancies, most frequently in patients with VTE or FMU.