BackgroundPreterm birth is an unresolved global health issue. The etiologies of preterm birth are complex and multifactorial. To examine risk factors related to preterm birth, a matched case–control study was conducted in a hospital in Beijing, China where little data on preterm birth have been published in the scientific literature.MethodsA 1:1 matched case–control study was conducted in 172 pairs of women with preterm birth (case group) and term delivery (control group). Eligible subjects were interviewed in person by well-trained investigators using a questionnaire. Information on obstetric diagnosis and newborns were abstracted from inpatients’ medical records. Univariate and multivariate conditional logistic regression models were used to measure the associations between related factors and preterm birth.ResultsUnivariate analysis showed that 6 of 12 factors were associated with preterm birth. Multivariate results showed that gestational hypertension (OR = 7.76), low gestational weight gain (OR = 3.02), frequent prenatal care (OR = 0.16), balanced diet (OR = 0.36), and high gestational weight gain (OR = 0.41) were associated with preterm birth.ConclusionThis study provides information on preterm birth in Beijing, China, and it also lends support to existing evidence about the role of maternal nutritional status, prenatal care and gestational hypertension as risk factors for preterm birth.

Propofol is the most widely used injectable general anesthetic. Its targets include ligand-gated ion channels such as the GABA A receptor, but such receptor-channel complexes remain challenging to study at atomic resolution. Until structural biology methods advance to the point of being able to deal with systems such as the GABA A receptor, it will be necessary to use more tractable surrogates to probe the molecular details of anesthetic recognition. We have previously shown that recognition of inhalational general anesthetics by the model protein apoferritin closely mirrors recognition by more complex and clinically relevant protein targets; here we show that apoferritin also binds propofol and related GABAergic anesthetics, and that the same binding site mediates recognition of both inhalational and injectable anesthetics. Apoferritin binding affinities for a series of propofol analogs were found to be strongly correlated with the ability to potentiate GABA responses at GABA A receptors, validating this model system for injectable anesthetics. High resolution x-ray crystal structures reveal that, despite the presence of hydrogen bond donors and acceptors, anesthetic recognition is mediated largely by van der Waals forces and the hydrophobic effect. Molecular dynamics simulations indicate that the ligands undergo considerable fluctuations about their equilibrium positions. Finally, apoferritin displays both structural and dynamic responses to anesthetic binding, which may mimic changes elicited by anesthetics in physiologic targets like ion channels.Most general anesthetics alter the activity of ligand-gated ion channels, and electrophysiology, photolabeling, and transgenic animal experiments imply that this effect contributes to the mechanism of anesthesia (1-9). Although the molecular mechanism for this effect is not yet clear, photolabeling studies indicate that anesthetics bind within the transmembrane regions of Cys-loop ligand-gated ion channels such as the nicotinic acetylcholine and the ␥-aminobutyric acid (GABA) 2 type A receptors (2, 9 -11). Practical difficulties associated with overexpression, purification, and crystallization of ion channels have thus far stymied investigation of the structural and energetic bases underlying anesthetic recognition. However, general anesthetics also bind specifically to sites in soluble proteins, including firefly luciferase, human serum albumin (HSA), and horse spleen apoferritin (HSAF) (12)(13)(14), and x-ray crystal structures have been determined for complexes of these proteins with several general anesthetics (14 -16). In particular, HSAF is an attractive model for studying anesthetic-protein interactions because it has the highest affinity for anesthetics of any protein studied to date, has a unique anesthetic binding site, and is a multimer of 4-helix bundles, much like the putative anesthetic binding regions in ligand-gated channels. In addition, apoferritin is commercially available and crystallizes readily. Most importantly, however, the affinity of HSAF f...

Propofol is the most commonly used sedative-hypnotic drug for noxious procedures, yet the molecular targets underlying either its beneficial or toxic effects remain uncertain. In order to determine targets and thereby mechanisms of propofol, we have synthesized a photoactivateable analogue by substituting an alkyldiazirinyl moiety for one of the isopropyl arms but in the meta position. m-Azipropofol retains the physical, biochemical, GABAA receptor modulatory, and in vivo activity of propofol and photoadducts to amino acid residues in known propofol binding sites in natural proteins. Using either mass spectrometry or radiolabeling, this reagent may be used to reveal sites and targets that underlie the mechanism of both the desirable and undesirable actions of this important clinical compound.

Background While dezocine is a partial mu opioid receptor agonist, it is not a controlled substance. Thus, the characterization of the molecular targets of dezocine is critical for scientific and clinical implications. The goal of this study is to characterize molecular targets for dezocine and their implications. Methods A binding screen for dezocine was performed on 44 available receptors and transporter proteins. Functional assays for the novel targets were performed along with computation calculations to locate the binding site. A G protein activation study was performed for the human kappa opioid receptor to determine whether dezocine is a kappa antagonist. Data are presented as mean ± SE. Results The affinities for dezocine were 3.7±0.7 nM for the mu receptor, 527±70 nM for the delta receptor, and 31.9±1.9 nM for the kappa receptor. Dezocine failed to induce G protein activation with kappa opioid receptor and concentration dependently inhibited kappa agonist (salvinorin A and nalbuphine) induced receptor activation, indicating that dezocine is a kappa antagonist. Two novel molecular targets (norepinephrine transporter, NET; and serotonin transporter, SERT) were identified. Dezocine concentration-dependently inhibited norepinephrine and serotonin reuptake in vitro. The half maximal inhibitory concentrations (expressed as pIC50) were 5.68±0.11 for NET and 5.86 ± 0.17 for SERT. Dezocine occupied the binding site for known NET and SERT inhibitors. Conclusions The unique molecular pharmacological profile of dezocine as a partial mu receptor agonist, a kappa receptor antagonist and a norepinephrine and serotonin reuptake inhibitor (via NET and SERT) was revealed. These discoveries reveal potentially important novel clinical implications and drug interactions of dezocine.