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Y Q Cao

Publications and source records attributed to Y Q Cao.

16 recordsLinked to original sources
PubMed2001

Impaired response to chemical irritation of the urinary tract in mice with disruption of the preprotachykinin gene.

Previous studies demonstrated that acute irritation of the lower urinary tract (LUT) induces the expression of the immediate early gene, c-fos, in lumbo-sacral spinal cord neurons "J. Neurosci. 12 (1992) 4878" "Am. J. Physiol. 265 (1993) 326" "Somatosens. Mot. Res. 15 (1998) 5". This effect was mediated in part by activation of capsaicin-sensitive bladder afferents "Am. J. Physiol. 265 (1993) 326". Here we investigate the role of preprotachykinin gene products (neurokinin A and substance P) in the response to bladder irritation in urethane-anesthetized mice. Acute irritation of the LUT (intravesical acetic acid) induced smaller numbers of Fos-positive neurons in the spinal cord of mice with a mutated preprotachykinin gene than in wild type mice. Increased Fos expression following LUT irritation or a sham operation in wild type mice was also significantly reduced by pretreatment with the NK2 antagonist, MEN 11420, but Fos expression in mutant mice was not altered by the antagonist. During cystometrograms, a significantly higher percentage (83%) of mutant mice exhibited urinary retention and overflow incontinence as compared to wild type controls. These findings suggest an involvement of tachykinins and NK2 receptors in the response to chemical irritation of the LUT in mice and also suggest that tachykinins contribute to the regulation of normal reflex bladder activity.

Acetic Acid↗
PubMed2000

[Detection of differentially expressed genes in hepatocellular carcinoma using DNA microarray].

Large scale gene expression profiles between normal hepatocytes and hepatocellular carcinomas are detected with high throughput microarray. DNA microarrays were made by spotting PCR products of 4,096 human cDNAs onto a specially treated glass slides. The probes were prepared by labelling normal tissue mRNA and cancer tissue mRNA with Cy3-dUTP and Cy5-dUTP separately through reverse transcription. The arrays were then hybridized against the cDNA probe mixture and the fluorescent signals were scanned. The obtained data were analyzed from 4 repeated experiments. There are 903 genes of which the average ratios between Cy3 signal and Cy5 signal are greater than 3.0. These genes identified through this approach are potential candidates for hepatocellular carcinoma diagnosis and therapy.

Carcinoma, Hepatocellular↗
PubMed1998

Primary afferent tachykinins are required to experience moderate to intense pain.

The excitatory neurotransmitter glutamate coexists with the peptide known as substance P in primary afferents that respond to painful stimulation. Because blockers of glutamate receptors reliably reduce pain behaviour, it is assumed that 'pain' messages are mediated by glutamate action on dorsal horn neurons. The contribution of substance P, however, is still unclear. We have now disrupted the mouse preprotachykinin A gene (PPT-A), which encodes substance P and a related tachykinin, neurokinin A. We find that although the behavioural response to mildly painful stimuli is intact in these mice, the response to moderate to intense pain is significantly reduced. Neurogenic inflammation, which results from peripheral release of substance P and neurokinin A, is almost absent in the mutant mice. We conclude that the release of tachykinins from primary afferent pain-sensing receptors (nociceptors) is required to produce moderate to intense pain.

Animals↗
PubMed1998

[GnRH receptor and the regulation of its gene expression].

The function of GnRH(gonadotropin-releasing hormone, LHRH) is mediated by GnRH receptor (GnRHR). The study on GnRHR is one of the highlights in neuroendocrinology and reproductive biology. The latest study of GnRHR, including molecular structure of GnRHR, regulation of GnRHR gene expression, distribution of GnRHR, the regulation of GnRHR by peptide and steroid hormone, as well as signal transduction mediated by GnRHR, are reviewed in the present article. Studies on GnRHR will make great contribution to the understanding of the regulation of reproduction and its action for therapy of malignant tumor.

Amino Acid Sequence↗
PubMed1997

[The synthetic fragment of rabbit blastocyst peptide2 and its physiological significance relevant to the mechanism of implantation].

The amino acid sequence of purified rabbit blastocyst peptide2 (RBP2) was analyzed. It contains 54 amino acids and it's sequence from aa4 to aa34 is the same as the N-terminal sequence of uteroglobin. An active antigenic region consisting of 15 aa residues (aa20-aa34) of the RBP2 was selected and designated as a synthetic peptide fragment (SPF). The effect of SPF on lymphocyte proliferation was analyzed by immunocytochemical assay detecting BrdU incorporation in the cellular DNA. The results indicated that no obvious inhibitory effect of SPF on T cell proliferation at concentrations ranging from 80 to 320 micrograms/ml was observed, while RBP2 at the concentrations ranging from 20 to 160 micrograms/ml had a significant effect in a dose dependent manner, suggesting that the immuno-suppressive effect of SPF is less than that of RBP2. We have also observed that SPF at concentrations ranging from 45 to 180 micrograms/ml inhibited PGF2 alpha secretion in a dose dependent manner. On the other hand, the 3H-leucine incorporation of rabbit endometrium was enhanced by SPF (180 micrograms/ml) and this action was blocked by addition of protein inhibitory agent, actidine.

Amino Acid Sequence↗
PubMed1993

Modulation of interferon secretion by concanavalin A and interleukin-2 in first trimester placental explants in vitro.

The human placenta has been demonstrated to be a site of interferon (IFN) production. We report here that early human placental explants in vitro release both type I (IFN-alpha and -beta) and type II (IFN-gamma) immunoreactive IFN. The mitogen concanavalin A (Con A) stimulated immunoreactive (ir-) IFN-gamma secretion in both a dose- and time-dependent manner, but had no significant effect on either ir-IFN-alpha or -beta release. The enhancement of ir-IFN-gamma secretion by Con A, at 2-20 micrograms/ml, was significant at 1 h and persisted until 24 h, but was not significant at 48 h. A high dose of recombinant human interleukin-2 (IL-2) stimulates the release of all three types of ir-IFNs, suggesting that interaction of IL-2 with its receptor might be one cause of the constitutive production of placental IFNs. The patterns of response to Con A and IL-2 were different from those of lymphocytes, providing indirect evidence suggesting that the source of these IFNs might not be lymphocytic. Taken together, these results indicate that first trimester human placental explants in vitro produce both type I and type II IFNs, the major IFN produced depending on the inducer. IL-2 may be one of the physiological inducers of placental IFNs.

Concanavalin A↗
PubMed1993

A study of protein and glycoprotein syntheses in pre-implantation mouse embryos using mini-2D-electrophoresis, video densitometer scanning and computer-image analysis.

In the present study, proteins and glycoproteins of mouse embryos at 2-cell, morula and blastocyst stages were analyzed. The techniques of 35S-Met incorporation, ConA antiserum-precipitating ConA-binding proteins, mini-2D-electrophoresis, fluorography, video densitometer scanning and the computer-image system were used for analyses. Results of the investigations indicated that proteins and glycoproteins were synthesized by the embryos in a gradual increase manner from 2-cell to blastocyst. A relatively large amount of glycoproteins was synthesized during the morula and blastocyst stages. Two specific small glycoproteins respectively with molecular weights about 6500 and 9000 and PIs at 5.0 and 6.5 were apparently synthesized in the blastocyst but not in the 2-cell or the morula.

Animals↗
PubMed1992

[Variation of WGA and PNA binding glycoproteins in early pregnant rabbit uterine fluid].

The qualitative and quantitative changes of two kinds of lectin (WGA, PNA) binding glycoproteins in early pregnant rabbit uterine fluid (D4-D12) were measured by Western blot and Video densitometer scanning methods. During peri-implantation stage (D6, D7 and D9), there are two WGA binding glycoproteins with MW about 42 kd, 28 kd and a PNA binding glycoprotein with MW 75 kd. It is suggested that the three proteins are stage-specific glycoproteins in rabbit uterine fluid in the course of implantation.

Animals↗
PubMed1992

Variations of lectin-binding glycoproteins in early pregnant rabbit embryo.

In the present study, the quantitative and qualitative changes of three kinds of lectin-binding glycoproteins of early pregnant rabbit embryos (D4-D12) were analyzed. The technique of Western blot, as well as video densitometer scanning and its analytic software was used for analysis. Results found that there were five specific lectin-binding glycoproteins in Day 4 to Day 6 blastocyst fluids: one ConA-binding glycoprotein about 70 kD, two WGA-binding glycoproteins respectively about 42 kD and 25 kD and two PNA-binding glycoprotein respectively about 180 kD and 75 kD. They disappeared immediately after implantation. It is demonstrated that there are stage-specific glycoproteins in rabbit blastocyst fluid which might be relevant to the recognition of pregnancy and implantation.

Animals↗
PubMed1991

The biological function of rabbit blastocyst peptides (RBPs).

The inhibitory effect of rabbit blastocystic peptides (RBPs) on lymphocyte transformation was studied by the method of measuring the incorporation of 3H-thymidine into DNA. The results indicated that RBPs inhibited PHA-stimulated rat and human lymphocyte transformation in vitro. In the concentration ranging from 40 to 200 micrograms/2.5 ml, the inhibition was dose-dependent. No obvious inhibitory action was found with hCG (16-128) IU/2.5 ml), progesterone (250 ng-1 microgram/2.5 ml) and pregnant rabbit serum. It was further demonstrated that RBPs at a higher dosage (200 micrograms/ml) was inhibitory to PGF2 alpha secretion. On the other hand, the 3H-leucine incorporation of rabbit endometrium was enhanced by these peptides, and this action could be blocked by the addition of actidine.

Animals↗
PubMed1988

Isolation and characterization of the specific peptides from rabbit blastocyst at peri-implantation stage with emphasis on their physiological significance relevant to the mechanism of implantation.

The secretory materials from the uterine flushings of the pregnant, non-pregnant and pseudopregnant rabbits were analysed by the method of SDS-polyacrylamide gel electrophoresis. The results demonstrated that there are three specific peptides in the pregnant uterine flushings with molecular weights of 3000, 4500 and 6000. No correspondent peptides were found in non-pregnant and pseudopregnant uterine flushings. The peptides were also isolated and identified from the blastocystic fluid. At least 4 peaks of small peptides were shown by high pressure liquid chromatography. The range of their isoelectrophoretic points is between pH 4.0-5.5 Concavalin A (Con A) affinitive electrophoresis indicated that they are glycopeptides in nature. The LH-RH A is able to exert inhibitory effects on the synthesis of these peptides. Their possible physiological function has been discussed.

Animals↗
PubMed1984

Identification and characterization of luteinizing hormone-releasing hormone (LH-RH) receptors in the endometrial tissue of pregnant rats.

The mechanisms by which LH-RH or its agonists inhibit decidua formation and terminate pregnancy in rats are not clear. Evidence so far accumulated indicates that the gonadotropic releasing hormone or its analogues may act directly on the uterus. If this is the case, then we would be able to identify LH-RH receptors in the endometrial tissue. The results presented here demonstrate that the homogenate preparation of rat endometrial tissue bound 125I-LH-RH with an affinity constant of Ka = 1.3 X 10(8) M-1. The binding capacity was measured as 236 fmole/mg protein. It was found that the binding is highly specific, because no binding was observed in a variety of non-target tissues, such as liver, kidney and muscle. Competitive binding with TRH, P substance and bradykinin did not occur under our experimental condition. It was of particular interest to note that Day 3 of pregnancy is a critical time showing a higher binding activity. The significance of work is discussed.

Animals↗
PubMed1982

Direct inhibition of testicular steroidogenesis and gonadotrophin receptor levels by [(imBzl)-D-His6, Pro9-NEt]GnRH and [D-Trp6, Pro9-NEt]GnRH, potent agonists of GnRH.

The effects of [(imBzl)-D-His6, Pro9-NEt]GnRH and [D-Trp6, Pro9-NEt]GnRH on testicular function in rats was evaluated. In adult rats the administration of 0.01, 0.1 or 10 micrograms of either agonist induced rapid increases in serum LH, FSH and testosterone (T) levels which started to decline within several hours. Both agonists caused a decrease in testicular LH and FSH receptor concentrations. The testicular FSH receptor concentration started to decline earlier than the LH receptor concentration but, both reached their lowest levels by day 2 after the administration of the agonists. The recovery of FSH receptor content was slower than that of LH. The extrapituitary effects of the 2 agonists were investigated in immature hypophysectomized animals. Administration of hCG (5 IU daily) to hypophysectomized rats for 5 days caused an increase in serum T levels. Concomitant administration of either of the agonists (10 micrograms) inhibited the steroidogenic action of hCG. Administration of the agonists alone caused a reduction in testicular LH receptor concentration in hypophysectomized rats. Treatment of the hypophysectomized rats for 0-4 days suggested that the direct antitesticular action of the agonists requires 1-2 days to become evident.

Animals↗