[Placental mechanisms underlying the effects of maternal stress on the fetal development].

Placenta is the only link between the pregnant woman and fetus, and the basis for maintaining the normal pregnancy process and fetal development. Maternal stress is the maternal physiological and psychological changes caused by various factors, characterized by the increased level of glucocorticoid, which affects the hypothalamic-pituitary-target gland axis and regulates the expression of target genes. Maternal stress also changes the weight, metabolism and nutrient transportation of the placenta, which will substantially influence the development of fetus.

Efficacy and safety of pulsatile gonadotropin-releasing hormone therapy in patients with congenital hypogonadotropic hypogonadism: a multicentre clinical study.

Background: Pulsatile gonadotropin-releasing hormone (GnRH) therapy may restore function of the hypothalamus-pituitary-gonad axis and induce spermatogenesis in male patients with congenital hypogonadotropic hypogonadism (CHH). The study sought to test the reliability of a newly developed Innopump hormone pump, and to confirm the efficacy and safety of pulsatile GnRH therapy (by Innopump hormone pump) in CHH patients.

Methods: From November 2017 to November 2018, 28 male patients with CHH were treated with pulsatile GnRH at Peking Union Medical College Hospital, Beijing Chaoyang Hospital, and Shandong Provincial Hospital.

Three new C steroidal glycosides isolated from and their potential inhibitory effects on tyrosine protein kinases.

Three new steroidal glycosides, metapregnoside A-C (-), together with one known compound, byzantionoside B (), were isolated from the fresh whole herb of by using high-speed countercurrent chromatography and semi-preparative liquid chromatography. Their structures and relative configurations were elucidated by spectroscopic methods including 1D NMR, 2D NMR and HR-ESI-MS. The potential targets of compound - were identified by virtual screening.

A rapid and practical prediction method for the Arizona solvent system family used in high speed countercurrent chromatography.

Selecting the appropriate solvent system is the key to the successful separation of samples by using countercurrent chromatography. Although high-speed countercurrent chromatography has been widely used in the separation and preparation of natural products, the selection of a solvent system has always been a stumbling block to the application of high-speed countercurrent chromatography. In order to explore a rapid and practical prediction method to select countercurrent chromatography solvent system, five linear prediction models of the Arizona solvent system family (HEMW) was established by using fourteen compounds with different structures and five HPLC columns of different brands.

Rational drug design of indazole-based diarylurea derivatives as anticancer agents.

A series of novel indazole-based diarylurea derivatives targeting c-kit were designed by structure-based drug design. The derivatives were prepared, and their antiproliferative activities were evaluated against human colon cancer HCT-116 cell line and hepatocellular carcinoma PLC/PRF/5 cell line. The antiproliferative activities demonstrated that six of nine compounds exhibited comparable activities with sorafenib against HCT-116.

Enhancing the biocatalytic manufacture of the key intermediate of atorvastatin by focused directed evolution of halohydrin dehalogenase.

Halohydrin dehalogenases (HHDHs) are biocatalytically interesting enzymes due to their ability to form C-C, C-N, C-O, and C-S bonds. One of most important application of HHDH was the protein engineering of HheC (halohydrin dehalogenase from Agrobacterium radiobacter AD1) for the industrial manufacturing of ethyl (R)-4-cyano-3-hydroxybutanoate (HN), a key chiral synthon of a cholesterol-lowering drug of atorvastatin. During our development of an alternative, more efficient and economic route for chemo-enzymatic preparation of the intermediate of atorvastatin, we found that the HheC2360 previously reported for HN manufacture, had insufficient activity for the cyanolysis production of tert-butyl (3 R,5 S)-6-cyano-3,5-dihydroxyhexanoate (A7).

[Aggregation Behavior of Collagen-Based Surfactant Molecules in Aqueous Solutions Based on Synchronization Fluorescence Spectrum Technology].

Due to the intrinsic fluorescence characteristic of tyrosine (Tyr) and phenylalanine (Phe), synchronization fluorescence spectrum technology which adopted the constant wavelength difference (Δλ = 15 nm) was selected to investigate the effects of collagen-based surfactant (CBS) concentration, pH, NaCt concentration and temperature on the aggregation state of CBS molecules in aqueous solutions. Meanwhile, temperature-dependent two-dimensional (2D) synchronization fluorescence correlation analyses was used to investigate the variation order of Tyr and Phe residues in CBS molecules with the change of temperature. The results showed that the characteristic absorption peaks located at 261 and 282 nm were attributed to Phe and Tyr, respectively.

[Specific interaction study in collagen/hyaluronic acid blends by two-dimensional infrared correlation spectroscopy].

Conformational changes and specific interactions in the collagen/hyaluronic acid blends were studied by two-dimensional infrared correlation spectroscopy with the interruption of the component of hyaluronic acid in collagen/ hyaluronic acid blends. It was found that the synchronous cross-peaks, derived from stretching vibrations of C=O at 1 694 cm(-1), wagging of N-H at 1 524 cm(-1) and in-plane deformation of N-H at 1 241 cm(-1) of collagen, were indicative of local conformational changes of collagen. The synchronous negative cross-peak between stretching vibrations of C-OH of hyaluronic acid at 1 045 cm(-1) and streching vibrations of C=O of collagen at 1 694 cm(-1) suggested that the interaction of hydrogen bonding existing between O-H of HA and C=O of collagen with the content of HA varied from 0% to 50%.

Genetic characterization of the chlorothricin gene cluster as a model for spirotetronate antibiotic biosynthesis.

The biosynthetic gene cluster for chlorothricin (CHL) was localized to a 122 kb contiguous DNA from Streptomyces antibioticus DSM 40725, and its involvement in CHL biosynthesis was confirmed by gene inactivation and complementation. Bioinformatic analysis of the sequenced 111.989 kb DNA region revealed 42 open reading frames, 35 of which were defined to constitute the CHL gene cluster.

Cloning and characterization of a bacterial iterative type I polyketide synthase gene encoding the 6-methylsalicyclic acid synthase.

Unusual polyketide synthases (PKSs), that are structurally type I but act in an iterative manner for aromatic polyketide biosynthesis, are a new family found in bacteria. Here we report the cloning of the iterative type I PKS gene chlB1 from the chlorothricin (CHL) producer Streptomyces antibioticus DSM 40725 by a rapid PCR approach, and characterization of the function of the gene product as a 6-methylsalicyclic acid synthase (6-MSAS). Sequence analysis of various iterative type I PKSs suggests that the resulting aromatic or aliphatic structure of the products might be intrinsically determined by a catalytic feature of the paired KR-DH domains in the control of the double bond geometry.