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Biomedical subjects

Li Jing

Publications and source records attributed to Li Jing.

13 recordsLinked to original sources
PubMed2006

The expression of CD9 in the peri-implantation mouse uterus is upregulated in an ovarian steroid hormone-dependent manner.

OBJECTIVE: To examine the spatiotemporal expression of CD9 protein in the peri-implantation mouse uterus as well as the effects of ovarian steroid hormones on CD9. DESIGN: Experimental animal study. SETTING: Reproductive biological center of Chinese Academy of Sciences. ANIMAL(S): Female Kunming white strain mice (6-8 weeks old). INTERVENTION(S): Subcutaneous injection of P(4)/E(2); uterine tissues were collected at different times after injection. MAIN OUTCOME MEASURE(S): The levels of protein and mRNA were detected in mouse uterus during peri-implantation and after steroid hormones treatment. RESULT(S): CD9 protein was expressed intensely in the stromal cells on days 1 and 2 of pregnancy. On days 3 and 4, the glandular and luminal epithelial cells exhibited accumulation of CD9 protein. After the initial attachment reaction on day 5, luminal epithelial and stromal cells immediately surrounding the blastocysts exhibited distinct accumulation of CD9. On days 6-8, the accumulation of CD9 occurred in decidual cells. Using ovariectomized mice, we also observed that both progesterone and estrogen upregulated uterine CD9 expression. CONCLUSION(S): The results of the current investigation showed that CD9 was differentially expressed in the uterus depending on the stage of implantation and was upregulated in ovarian steroid hormone-dependent manner, implicating multiple roles of CD9 in the regulation of embryo implantation during the peri-implantation period.

Animals↗
PubMed2006

Suppressed anion chromatography using mixed zwitter-ionic and carbonate eluents.

Effect of mixed eluents which contain zwitterions such as 2-(N-morpholino)ethanesulfonic acid (MES), 3-(N-morpholino)propanesulfonic acid (MOPS), 2-(cyclohexylamino)ethanesulfonic acid (CHES) and 3-(cyclohexylamino)-1-propanesulfonic acid (CAPS) and carbonate for suppressed conductivity ion chromatography (IC) were studied. The retention behaviors of all species were affected with different anion exchange columns when adding some zwitterion into carbonate eluent. The retention time of all species, especially those of strong retetion, was substantially shortened in AS14A column with either Na(2)CO(3)/CHES or Na(2)CO(3)/CAPS as eluent while a general increase in retetion time was noticed in AS9-HC column. Low pH of eluent was achieved when zwitterion was added. Without much changes in the background conductivity after suppressed, CHES could be used as suppressed conductivity ion chromatography eluent for determination of species unstable in strong alkaline, such as determination of phosphate in heteropoly acid (HPA) samples in AS14 column. The mixed eluent could also affect the selectivity when it was applied to the study of simultaneous separation of anions and cations in AS9-HC column by suppressed ion chromatography.

Acids↗
PubMed2006

Over-expression of extracellular signal-regulated kinase in vascular smooth muscle cell of hypertensive rats.

OBJECTIVE: To investigate whether extracellular signal-regulated kinase (ERK1/2) was involved in changes of vascular smooth muscle cell (VSMC) under hypertension. METHODS: Two-kidney one clip Wistar hypertensive rats (WHR) were sacrificed and their right kidneys were harvested 4 weeks after surgery. The spontaneously hypertensive rats (SHR) were divided into 4, 8, and 16 weeks old groups (SHR4w, SHR8w, and SHR16w), respectively. The control group were sham operated age-matched Wistar rats. Immunohistochemical technique and Western blotting were applied to study ERK1/2 protein expression in VSMC of the renal vascular trees in WHR, SHR, and control rats. RESULTS: Blood pressure in two-kidney one clip WHR obviously increased at one week after surgery, and reached to 198. 00 +/- 33. 00 mm Hg at the end of experiment, significantly higher than that in the control rats (P < 0.01). Blood pressure in SHR4w (108.00 +/- 11.25 mm Hg) was similar to that in the controls. However, it rose to 122.25 +/- 21.75 mm Hg in SHR8w, and even up to 201.75 +/- 18.00 mm Hg in SHR16w, which were significantly higher than that of both the SHR4w and the controls (P < 0.01). The rate and degree of glomerular fibrosis in WHR were significantly higher than controls (P < 0.05). Hyaline degeneration of the afferent arterioles was found in WHR. In contrast, either fibrosis of glomerulus or hyaline degeneration of the arterioles or protein casts was not observed in SHR4w, SHR8w, and SHR16w. Immunohistochemical staining results showed expression of ERK1 was similar to that of ERK2. The positive rates of ERK2 staining in VSMC of afferent arterioles, interlobular, interlobar, and arcuate arteries in two-kidney one clip WHR were significantly higher (7.09% +/- 1.75%, 14.57% +/- 4.58%, 29.44% +/- 7.35%, and 13.63% +/- 3. 85%, respectively) than that of the controls(P < 0.01). The positive rates of ERK2 staining in VSMC at afferent arterioles, interlobular, interlobar, and arcuate arteries in SHR16w were significantly higher (12.09% +/- 1.40%, 24.17% +/- 6.92%, 32.44% +/- 4.05%, and 18.61% +/- 3.35%, respectively) than that of the controls (P < 0.01), too. The expression of ERK1/2 protein of kidney in WHR and SHR16w was significantly higher than that in the controls by Western blotting assay (P < 0.01). CONCLUSION: Extracellular signal transduction system are highly expressed in kidney VSMC of two-kidney one clip WHR and SHR. Phospho-ERKI/2 may play an important role in VSMC hypertrophy and hyperplasia under hypertension.

Animals↗
PubMed2006

P21ras and phosphorylated extracellular signal-regulated protein kinase are highly expressed in vascular smooth muscle cells of hypertensive rats.

OBJECTIVE: To investigate the molecular mechanisms of vascular smooth muscle cell (VSMC) hyperplasia and extracellular signal-regulated protein kinase 1/2 (ERK 1/2) phosphorylation of VSMCs under the condition of hypertension. METHODS: Wistar rat models of two kidney-one clip hypertension (2K1C) were established and their right kidneys were harvested 4 weeks after the operation. Immunohistochemistry and Western blotting were performed to detect phospho-ERK1/2 and P21ras protein expression in the VSMCs of the renal arterioles, and the results were compared with those from 16-week-old spontaneous hypertension rats (SHR16) and control rats. RESULTS: The blood pressure of 2K1C Wistar rats was significantly increased from 104-/+18 mmHg to 198-/+33 mmHg at the end of the experiment, and the blood pressure of SHR16 reached 163-/+23 mmHg, significantly higher than that of the control rats (P<0.01). Compared with the control group, 2K1C rats showed obvious glomerular fibrosis (P<0.05) with hyaline degeneration of the afferent arterioles. In contrast, neither glomerular fibrosis nor hyaline degeneration of arterioles, nor protein cast was observed in SHR16. In 2K1C rats and SHR16, the positivity rates of phospho-ERK1/2 and p(21ras) staining in the VSMCs of the afferent arterioles and the interlobular, interlobar and arcuate arteries was significantly higher than those of the controls (P<0.01), and the expression of phospho-ERK1/2 and P(21ras) protein in the kidney was also significantly higher as revealed by Western blotting (P<0.01). CONCLUSION: High expression of ERK1/2 and P(21ras) in the renal arteriole VSMCs of 2K1C hypertensive rats and SHR may play an important role in VSMC hypertrophy and proliferation in hypertension.

Animals↗
PubMed2005

Hyperglycemia increased brain ischemia injury through extracellular signal-regulated protein Kinase.

This study was to examine the alterations in the phosphorylation of mitogen-activated protein kinase (MAPK) family in transient brain ischemia under a hyperglycemia and to highlight the molecular mechanisms by which hyperglycemia exacerbates brain damage resulting from stroke. Extracellular signal-regulated protein kinase (ERK) expression was studied in rats subjected to global brain ischemia with pre-ischemic normoglycemic (CIN) and hyperglycemic (CIH) conditions. In another group, the hyperglycemic ischemic rats were pretreated with ERK inhibitor U0126 (U0126). Increased phospho-ERK1/2 immunoreactive neurons in the cingulate cortex and hippocampal CA3 were detected in CIN after ischemia and reperfusion. The numbers of phospho-ERK1/2-positive neurons were further increased significantly in CIH compared to the CIN. Pretreatment with U0126 in CIH rats significantly decreased ERK1/2 immunoreactive cells. Western blot analyses confirmed that phospho-ERK1/2 increased significantly after 30 min ischemia and reperfusion compared to non-ischemic controls in both the CIN and CIH groups. The increase of phospho-ERK1/2 was more prominent in the CIH than in the CIN group after 3 and 6h of reperfusion. Treatment with U0126 significantly reduced phospho-ERK1/2 in the CIH group. The findings presented here suggest that ERK1/2 may play a role in mediating neuronal cells death under hyperglycemic condition.

Animals↗
PubMed2005

Standardizing global gene expression analysis between laboratories and across platforms.

To facilitate collaborative research efforts between multi-investigator teams using DNA microarrays, we identified sources of error and data variability between laboratories and across microarray platforms, and methods to accommodate this variability. RNA expression data were generated in seven laboratories, which compared two standard RNA samples using 12 microarray platforms. At least two standard microarray types (one spotted, one commercial) were used by all laboratories. Reproducibility for most platforms within any laboratory was typically good, but reproducibility between platforms and across laboratories was generally poor. Reproducibility between laboratories increased markedly when standardized protocols were implemented for RNA labeling, hybridization, microarray processing, data acquisition and data normalization. Reproducibility was highest when analysis was based on biological themes defined by enriched Gene Ontology (GO) categories. These findings indicate that microarray results can be comparable across multiple laboratories, especially when a common platform and set of procedures are used.

Gene Expression Profiling↗
PubMed2005

A standardized surgical technique for mastoscopic axillary lymph node dissection.

To standardize the surgical technique for mastoscopic axillary lymph node dissection (MALND). Mastoscopic lymph node dissection was performed consistently by a group of surgeons in 316 cases of breast cancer. The mean operation time was 46.7 minutes with minimal bleeding, and the median number of lymph nodes dissected at each operation was 17.0. There were no operative complications in any case, nor did trocar implantation or tumor diffusion occurring during the mean follow-up time of 15.1 months. MALND is distinctive and practicable in operative anatomy as well as safe and convenient. The location of critical anatomy such as the intercostobrachial nerve, lateral thoracic artery, medial thoracic nerve, and thoracoepigastric vein should be clearly identified to avoid damage to them, so that is the great advantage of MALND.

Adult↗
PubMed2005

[Intervention of cetirizine on monocyte chemoattractant protein-1 in cutaneous inflammation].

AIM: To study the intervention of cetirizine on monocyte chemoattractant protein-1 (MCP-1) in different cutaneous inflammation models. METHODS: Histamine and IFN-gamma stimulated dermal fibroblast cells and HaCaT cells to mimic cutaneous inflammation. Expression of MCP-1 was assessed by means of RT-PCR and ELISA. RESULTS: Compared with the control group of dermal fibroblast (DF) cells and HaCaT cells, MCP-1 mRNA was significantly upregulated by histamine (10 micromol x L(-1)) and IFN-gamma (20 ng x mL(-1)). The protein secretions of MCP-1 were increased 3.5 fold and 8.4 fold in DF cells, respectively. The similar tendency was observed in HaCaT cells. The enhancing effects of histamine and IFN-gamma on MCP-1 protein production were significantly inhibited by cetirizine (1 and 10 micromol x L(-1)) in DF and HaCaT cells. CONCLUSION: Cetirizine may exert the anti-inflammatory effect of skin via inhibiting MCP-1 expression.

Cell Line↗
PubMed2003

Predicting protein structure from long-range contacts.

Short-range and long-range contacts are important in forming protein structure. The proteins can be grouped into four different structural classes according to the content and topology of alpha-helices and beta-strands, and there are all-alpha, all-beta, alpha/beta and alpha+beta proteins. However, there is much difference in statistical property for those classes of proteins. In this paper, we will discuss protein structure in the view of the relative number of long-range (short-range) contacts for each residue. We find the percentage of residues having a large number of long-range contacts in protein is small in all-alpha class of proteins, and large in all-beta class of proteins. However, the percentage of residues is almost the same in alpha/beta and alpha+beta classes of proteins. We calculate the percentage of residues having the number of long-range contacts greater than or equal to (>/=) N(L)=5, and 7 for 428 proteins. The average percentage is 13.3%, 54.8%, 41.4% and 37.0% for all-alpha, all-beta, alpha/beta and alpha+beta classes of proteins with N(L)=5, respectively. With N(L) increasing, the percentage decreases, especially for all-alpha class of proteins. In the meantime, the percentage of residues having the number of short-range contacts greater than or equal to N(S) (>/=N(S)) in protein samples is large for all-alpha class of proteins, and small for all-beta class of proteins, especially for large N(S). We also investigate the ability of amino residues in forming a large number of long-range and short-range contacts. Cys, Val, Ile, Tyr, Trp and Phe can form a large number of long-range contacts easily, and Glu, Lys, Asp, Gln, Arg and Asn can form a large number of long-range contacts, but with difficulty. We also discuss the relative ability in forming short-range contacts for 20 amino residues. Comparison with Fauchere-Pliska hydrophobicity scale and the percentage of residues having large number of long-range contacts is also made. This investigation can provide some insights into the protein structure.

Amino Acids↗
PubMed2003

The potential molecular targets of marine sulfated polymannuroguluronate interfering with HIV-1 entry. Interaction between SPMG and HIV-1 rgp120 and CD4 molecule.

The potential targets of marine sulfated polymannuroguluronate (SPMG) involved in inhibition of HIV-1 entry were investigated by surface plasmon resonance and flow cytometry. Results indicated that binding of SPMG either to soluble oligomeric rgp120 or to complexed rgp120-sCD4 mainly resided in V3 loop region. In addition, SPMG was shown to be less accessible for sCD4 when sCD4 had pre-interacted with rgp120, though SPMG per se multivalently bound to sCD4 with relatively low affinity. While the pre-incubation of SPMG with rgp120 caused a partial blockade of rgp120 binding to sCD4, suggesting that SPMG either shared common binding sites on gp120 with sCD4 or masked the docking sites of gp120 for sCD4. Taken together, V3 domain was demonstrated to be the major site mediating interaction of SPMG with complexed rgp120-sCD4. It seems likely that SPMG binds to both rgp120 and sCD4, but has less accessibility for sCD4 when sCD4 has already bound to rgp120. Nevertheless, addition of SPMG either prior to or after the interaction of rgp120 with sCD4 may suppress rgp120 binding to sCD4. The exact pattern of this trimolecular complex formation at the cell membrane-anchored virus level requires further clarification.

Anti-HIV Agents↗
PubMed2002

[Expression and clinical significance of surfactant protein D mRNA in peripheral blood of lung cancer patients].

BACKGROUND AND OBJECTIVES: The sensitive detection of circulating tumor cells in lung cancer patients is very important for prognosis and selection of appropriate treatment modalities. Based on recent promising data, the authors established reverse transcriptase (RT)-PCR with primers specific for surfactant protein D (SP-D) gene to detect circulating tumor cells in the peripheral blood of lung cancer patients, and to initiatively discuss its clinical significance. METHODS: The expression of SP-D mRNA was analyzed by an improved nested RT-PCR in the peripheral blood of 26 lung cancer patients with metastases, 37 lung cancer patients without metastases, 15 benign pneumonia patients, and 15 healthy volunteers. RESULTS: 1) The sensitivity of the method was 1 x 10(-6), with high level of specificity. 2) Using this method, the positive detection rate of the expression of SP-D mRNA was 92.3% (24/26) and 24.3% (9/37) in the peripheral blood of lung cancer patients with and without metastases, respectively. While no sample was positive for SP-D mRNA expression in the benign pneumonia patients and in the healthy volunteers. CONCLUSIONS: SP-D mRNA might be a valuable marker to detect circulating tumor cells in the peripheral blood of lung cancer patients. This method may be a valuable tool for early identification of metastases in asymptomatic lung cancer patients. Furthermore, it can also provide important clinical information for the evaluation of prognosis and in the selection of appropriate treatment strategies.

Actins↗
PubMedDate not supplied

Determination of multiclass pesticide residues in apple juice by gas chromatography-mass selective detection after extraction by matrix solid-phase dispersion.

A multiresidue method is described for the analysis of 106 multiclass pesticides (organochlorine, organophosphate, carbamate, pyrethroid, and triazine classes) in apple juice in a single injection. The determination procedure was based on matrix solid-phase dispersion of juice on diatomaceous earth in a glass column and subsequent extraction with a mixture of hexane-dichloromethane (1 + 1) at a flow rate of 5 mL/min. The analytes were determined by capillary gas chromatography with mass spectrometric detection and confirmed by their retention times and ion ratios. The coefficients of variation for analysis of samples fortified over the range of 0.01-0.2 mg/kg were 1.62 to 18.4%, and the recoveries for all analytes were between 70 and 110%.

Beverages↗