Publications by authors named "Qing Lei Li"

Dairy cows undergo dramatic physiological changes during the transition from late pregnancy to early lactation, which make them vulnerable to metabolic stress and immune dysfunction. The objective of this study was to evaluate the effects of a commercial beta-1,3-glucan product (Aleta™, containing 50% beta-1,3-glucan) on productivity, immunity and antioxidative status in transition cows. Fifty-four multiparous Holstein cows received a control diet or a diet supplemented with 5 or 10 g of beta-1,3-glucan per cow per day from 21 days before expected calving to 21 days after parturition.

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Objectives of this study were to evaluate the alleviating effects of a commercial beta-1,3-glucan product (Aleta, containing 50% beta-1,3-glucan, Kemin Industries) on metabolic stress in transition Holstein cows as reflected by circulating metabolites and enzymes. Fifty-four multiparous Holstein cows were randomly allocated to three groups with 18 cows each. Cows in each group received a commercial basal diet or the basal diet supplemented with Aleta calculated to supply 5 or 10 g of Aleta per cow per day.

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Objective: To explore syndrome and treatment laws for treating diseases of the pulmonary system by establishing database based on clinical works by modern famous veteran doctors of Chinese medicine (CM).

Methods: Clinical experience and literature of medical records in clinical works by modern famous veteran doctors of CM were taken as data source. Database was established by fields and program design.

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Previous studies have demonstrated that the ubiquitin-proteasome pathway plays an important role in embryo implantation. Low molecular mass polypeptide (LMP) 2 and LMP7 are the two subunits of 20S proteasome, which are critical for proteasome activity. To further elucidate the roles of LMP2 and LMP7 in embryo implantation during early pregnancy, we cloned partial sequences of the LMP2 and LMP7 genes and studied the spatiotemporal expression of LMP2 and LMP7 in rhesus monkey (Macaca mulatta) uteri on Days 12, 18, and 26 of pregnancy.

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Transforming growth factor-beta1 (TGF-beta1) plays a pivotal role in the angiogenesis during the development of placenta, but the intracellular signaling mechanism by which TGF-beta1 stimulates this process remains poorly understood. In this article, we demonstrated that exposure of normal human cytotrophoblast cells to TGF-beta1 stimulated the secretion of the VEGF gene encoding vascular endothelial growth factor, which is a key factor in angiogenesis. Meanwhile, treatment of normal human cytotrophoblast cells with TGF-beta1-induced expression of HIF-1a, the regulated subunit of hypoxia-inducible factor 1, a known transactivator of the VEGF gene.

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SMADs are intracellular signaling molecules that transmit signals elicited by members of transforming growth factor-beta (TGF-beta) superfamily. To decipher the mechanism of TGF-beta signaling during the estrous cycle and implantation, we performed in situ hybridization to investigate the expression patterns of mRNAs for Smad2 and Smad4 in rat endometrium during the estrous cycle and on Days 0.5, 1.

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During early pregnancy, an environment of relative low oxygen tension is essential for normal embryonic and placental vasculature. In low-oxygen conditions, the hypoxic-inducible factor-1 (HIF-1), composed of alpha and beta subunits, controls the expression of a number of genes such as vascular endothelial growth factor (VEGF), a key angiogenic factor. The recent studies in some tumor cells have found that the labile component, HIF-1 alpha, is not only activated by hypoxia but also by peptides such as interleukin-1 (IL-1) in normoxia.

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Previous studies have documented that ubiquitin-related proteins are present in human, baboon, rhesus monkey, cow, sheep, and mouse pregnant uteri, indicating that the ubiquitin-proteasome pathway (UPP) may be involved in the extensive uterine remodeling during mammalian early pregnancy, but there is still no direct evidence. A mouse intrauterine injection model was employed to study the direct effect of the UPP on mouse embryo implantation and its possible mechanisms. On Day 3 of pregnancy in each mouse, one of the uterine horns in each mouse was injected with different concentrations of lactacystin, a specific proteasome inhibitor, or anti-ubiquitin antibody, and the other side was used as a control.

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Liver receptor homologue 1 (LRH-1) is a member of the nuclear receptor superfamily originally found in liver cells. LRH-1 participates in regulation of cholesterol metabolism and bile acid synthesis. Recent studies have shown that LRH-1 is even more highly expressed in the ovary, and LRH-1 has been implicated as a key transcriptional regulator of cytochrome P450 aromatase (P450arom) in vitro.

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The role of matrix metalloproteinases (MMP), especially newly described MMP, in trophoblast invasion during human embryo implantation is poorly understood. In this report, using a model of early pregnancy in the rhesus monkey, we have examined the expression and localization of the most recently identified MMP, MMP-28/epilysin, transcript and protein in macaque uterine samples on days 12, 18 and 26 of pregnancy. MMP-28 mRNA expression was shown by in-situ hybridization after day 12 of pregnancy, and both the syncytial and the cytotrophoblastic cell layers of placental villi, the cytotrophoblast cells of the trophoblastic column, and the extravillous trophoblast cells of trophoblastic shell were primary producers of MMP-28 transcript.

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The expression levels of nuclear receptor coregulators in specific tissue compartments and cells are thought to influence the expression of hormone-responsive genes involved in metabolism, development, and reproduction. RAP250 is a novel nuclear receptor coactivator highly expressed in brain and reproductive organs. To investigate the possible involvement of RAP250 in tissue-specific regulation of ovarian function, untreated immature, pregnant mare's serum gonadotropin luteinizing hormone (PMSG-LH)-primed, cycling, and pregnant rat models were used to study the localization and expression of RAP250 mRNA in rat ovary by in situ hybridization (ISH) and reverse transcriptase polymerase chain reaction (RT-PCR).

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Extensive tissue remodeling occurs in the corpus luteum (CL) during both formation and luteolysis. Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are believed to play pivotal roles in these processes. In the present study, to evaluate the potential roles of matrix degrading proteases in luteal development and regression, we examined gelatinases and TIMP-1, -2, -3 mRNA expressions, as well as gelatinase activity in rat CL during pregnancy and postpartum using Northern blot, in situ hybridization, and gelatin zymography, respectively.

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