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Xin Zhou

Publications and source records attributed to Xin Zhou.

At least 73 records · Page 4Linked to original sources
PubMed2005

Detecting the polymorphisms of paraoxonase (PON) cluster in Chinese Han population based on a rapid method.

BACKGROUND: An increased risk of coronary heart disease has been shown to be associated with polymorphisms in PON1 gene in different populations. Polymorphisms in PON2 gene have been associated with the level of plasma lipoproteins and glucose and are thought to play a role in atherosclerosis. METHODS: To detect PONs polymorphisms more rapidly and reliably, we modified and improved the method established by Motti et al. We redesigned the primer for amplifying the common polymorphism at position 311 of PON2, which produced more reliable and efficient amplification. RESULTS: A second common polymorphism at codon 148 was also detected by our new method, as were the 2 polymorphisms in the PON1 gene. The new method allowed identification of 4 polymorphisms (PON1-192, PON1-55, PON2-148 and PON2-311) simultaneously. The PONs genotypes of 82 healthy persons were identified by this method. The allelic frequencies were: PON1-192: Q 46.3%, R 53.7%; PON1-55: L 95.1%, M 4.9%; PON2-148: A 85.4%, G 14.6%; PON2-311: S 77.4%, and C 22.6%, respectively. CONCLUSION: This method represents a simple, economical and time-saving technique to simultaneously detect 4 polymorphisms in the PON cluster. It provides a useful application to enable further study of the relationship between PON1 and PON2 and their role in atherosclerosis.

Aged↗
PubMed2005

Polymorphisms of estrogen-metabolizing genes and breast cancer risk: a multigenic study.

BACKGROUND: Endogenous estrogen plays a very important role in the carcinogenesis and progression of breast cancer. The enzymes involved in the biosynthesis and metabolism of estrogen have been proposed to contribute to this effect. To examine this hypothesis, we conducted a case-control study to investigate the relationship between polymorphisms of genes responsible for estrogen biosynthesis (CYP17, cytochrome P450c17a and CYP19, aromatase cytochrome P450) and estrogen sulfation of inactivation (SULT1A1, sulfotransferase1A1) and the risk of breast cancer in Chinese women. METHODS: This study involved 213 breast cancer patients and 430 matched controls. PCR-based restriction fragment length polymorphism (RFLP) and short tandem repeat polymorphism (STRP) assays were used to detect the mononucleotide transition of CYP17 and SULT1A1 and tandem repeat polymorphism of CYP19. Logistic regression analyses were used to determine OR and 95% CI of each and all three high-risk genotypes, of all three genotypes combined, and of estrogen exposure factors. The relationship between each high-risk genotype and clinicalpathological characteristics were also assessed. RESULTS: The frequency of A2 allele of CYP17 was 49.8% in cases and 49.1% in controls (P = 0.82). The frequency of His allele of SULT1A1 was significantly higher in cases (13.6%) than in controls (9.5%) (P < 0.05). There was also significant difference of the (TTTA) 10 allele of CYP19 which was 12.4% in cases and 8.2% in controls (P < 0.05). When the CYP17 A2 allele, CYP19 (TTTA) 10 and SULT1A1 His allele were considered as the "putative high-risk" genotype, there was an increased risk of breast cancer with the number of high-risk genotypes in a dose-response effect (trend, P = 0.05). In multivariate analysis, the SULT1A1 genotype remained the most significant determinant for breast cancer, with OR = 2.37 (95% CI 1.23-4.74), followed by CYP19, with OR = 1.75 (95% CI 1.27-3.56). The (TTTA) 10 allele of CYP19 was associated with tumor size, and the His allele of SULT1A1 associated with status of lymph node metastasis. CONCLUSIONS: This study supports the hypothesis that breast cancer can be initiated by estrogen exposure and that estrogen metabolizing genes are involved in this mechanism. This multigenic model is useful for identifying individuals who are at higher risks of breast cancer.

Adult↗
PubMed2005

Flow boundary conditions for chain-end adsorbing polymer blends.

Using the phenol-terminated polycarbonate blend as an example, we demonstrate that the hydrodynamic boundary conditions for a flow of an adsorbing polymer melt are extremely sensitive to the structure of the epitaxial layer. Under shear, the adsorbed parts (chain ends) of the polymer melt move along the equipotential lines of the surface potential whereas the adsorbed additives serve as the surface defects. In response to the increase of the number of the adsorbed additives the surface layer becomes thinner and solidifies. This results in a gradual transition from the slip to the no-slip boundary condition for the melt flow, with a nonmonotonic dependence of the slip length on the surface concentration of the adsorbed ends.

Journal Article↗
PubMed2005

Catalytic asymmetric cyanosilylation of ketones by a chiral amino acid salt.

In this Communication, we describe the first highly enantioselective cyanosilylation of ketones catalyzed by simple chiral amino acid salt. A broad range of aromatic, alpha,beta-unsaturated, heterocyclic ketones catalyzed by l-phenylglycine sodium salt gave the corresponding trimethylsilyl ethers of cyanohydrins in 75-96% yields with 86-97% enantioselectivities. A catalytic cycle based on experimental phenomena and studies has been proposed to explain the origin of this activation. The reaction employed commercially available and fully recyclable catalysts and involves a simple experimental procedure.

Journal Article↗
PubMed2005

Application of preparative high-speed counter-current chromatography for isolation and separation of schizandrin and gomisin A from Schisandra chinensis.

Following an initial cleaning-up step on the D101 macroporous resin, a preparative high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (1:0.9:0.9:1, v/v) was used to isolate and separate schizandrin and gomisin A from Schisandra chinensis. A total of 107 mg schizandrin and 36 mg gomisin A with purities of 99.5% and 99.1% were obtained from 400 mg crude extract in one-step elution and less than 3 h, and the structure identification was performed by UV, IR, MS, 1H NMR and 13C NMR.

Chromatography, High Pressure Liquid↗
PubMed2005

Phenytoin can accelerate the healing process after experimental myocardial infarction?

BACKGROUND: Over-degradation and/or inadequate accumulation of extracellular matrix after myocardial infarction (MI) may lead to adverse ventricular remodeling, even ventricular aneurysm or rupture. Phenytoin can increase gingival overgrowth by stimulating the proliferation of connective tissue, which implies a novel way to hasten the healing process after MI. METHODS: Experimental MI was induced by permanent coronary ligation. Surviving rats after MI were randomly divided into phenytoin, captopril, phenytoin plus captopril, operation control and sham operation group. Picrosirius red staining plus polarized microscopy was used for collagen analysis. Left ventricular passive pressure-volume relationship was determined ex vivo. The effects of phenytoin concentration gradient (0, 1.25, 2.5, 5.0, 10.0, and 20.0 microg/mL) on transforming growth factor-beta1 (TGF-beta1) mRNA and protein expression by neonatal rat cardiac fibroblast were determined using semi-quantitative RT-PCR and ELISA, respectively. Peritoneal macrophage was incubated with same gradient of phenytoin concentration. Then the supernatant was harvested to stimulate another 6 groups of cardiac fibroblast, to investigate possible role mediated by macrophage. RESULTS: Phenytoin treatment could promote type I collagen cross-linking level and ratio of type I/III collagen in the infarcted region and had no obvious side effect on interstitial collagen volume fraction, subtype ratio and distribution in non-infarcted region. Phenytoin-treated hearts exhibited attenuation of global ventricular dilation. Phenytoin alone had no direct effects on rat cardiac fibroblast proliferation and collagen production in vitro, but phenytoin-stimulated macrophage could exert a positive influence on cardiac fibroblast TGF-beta1 mRNA and protein production, which exhibited a dose-dependent manner. CONCLUSIONS: Phenytoin can accelerate the healing process in the infarcted region and has no obviously detrimental influence on collagen accumulation in non-infarcted region, which implies a potential benefit to patients undergoing early post-infarction ventricular remodeling process.

Animals↗
PubMed2005

Detection of peritoneal micrometastasis by reverse transcriptase-polymerase chain reaction for heparanase mRNA and cytology in peritoneal wash samples.

BACKGROUND: Peritoneal dissemination is the most common pattern of metastasis in advanced gastric carcinoma with serosal invasion. In the present study, we have reported the clinical relevance of a new diagnostic method with reverse transcriptase-polymerase chain reaction (RT-PCR) assay using heparanase as a target gene for detection of free cancer cells in peritoneal washes. METHODS: Intraoperative peritoneal washes were obtained from 48 patients who underwent surgery for gastric cancer. RT-PCR analysis with primers specific for heparanase and conventional cytological examination were performed subsequently. RESULTS: Heparanase RT-PCR was capable of detecting at least 10 tumor cells in 10 ml peritoneal wash fluid. There was no detectable heparanase expression in normal gastric epithelial cells and peritoneal wash samples from patients with benign disease. Twenty-five (52%) patients with gastric cancer had a detectable heparanase expression. Its positive rate was 100% and 59% for the cases with clinically evident peritoneal metastasis and serosal invasion, respectively, both of which are higher than that of cytology. CONCLUSIONS: Heparanase mRNA detected in peritoneal lavaged fluid might indicate the presence of free cancer cells in peritoneal cavity. The high sensitivity of RT-PCR based heparanase assay made it a candidate molecular marker for detecting peritoneal micrometastasis.

Adult↗
PubMed2005

[Transumbilical laparoscopic operation for the incarcerated oblique inguinal hernia in the infants].

OBJECTIVE: To evaluate the clinical application of transumbilical double-hole laparoscopic operation for incarcerated inguinal hernia in the infants. METHODS: Forty-eight cases with incarcerated inguinal hernia (male 39, female 9) aging from 4 months to 3 years (mean 1.2 +/- 0.8 years) received the laparoscopic transumbilical double-hole operation (LTO group) during April.2003 to April.2004. Thirty cases were left side incarcerated inguinal hernia, 12 cases were right side and 6 cases were bilateral. Fifty infants of incarcerated inguinal hernias treated with traditional operation served as controls (TO group). The mean operation time, length of stay, return of bowel function and postoperative complication were compared between the two groups. RESULTS: All cases of both groups recovered without any complication. The operation time, average hospitalization and return of bowel function in LTO were (30 +/- 5) min, (7.8 +/- 0.3) h and (4.4 +/- 0.3) d, respectively, and in TO were (43 +/- 6) min, (23.3 +/- 2.4) h and (6.7 +/- 0.4) d, respectively. There was a significant difference in the two groups (P < 0.05). The patients in both groups were followed up for 3 months to one year. LTO group had no recurrence or atrophy of testis and TO group had one relapse of hernia. CONCLUSIONS: Transumbilical double-hole laparoscopic operation is safe and microinvasive. It is a useful microinvasive procedure in the treatment of incarcerated inguinal hernia for infant.

Child, Preschool↗
PubMed2005

Effect of sinomenine on cytokine expression of macrophages and synoviocytes in adjuvant arthritis rats.

For exploring the mechanism of the anti-inflammatory and anti-rheumatic effect of sinomenine (SN), the actions of different dosage of SN were observed in vitro on the expression of cytokines, tumor necrosis factor (TNF-alpha) and interleukin-1beta (IL-1beta), as well as the activity of nuclear factor-kappaB (NF-kappaB) and the inhibitory kappaB-alpha (IkappaB-alpha) protein level of peritoneal macrophages (PMs) and synoviocytes in adjuvant arthritis (AA) rats. In this study, the experimental rat model of AA was used and PMs and synoviocytes were collected. The mRNAs of TNF-alpha and IL-1beta were detected with reverse transcription-polymerase chain reaction (RT-PCR) and NF-kappaB activity was measured by electrophoretic mobility shift assay (EMSA). The IkappaB-alpha protein level in the cytoplasma was detected by Western blot. Our results showed that expression of mRNAs of TNF-alpha and IL-1beta and NF-kappaB activity by PMs and synoviocytes were markedly increased compared to control group (P<0.05). In a definite concentration ranging from 30 to 120 microg/ml, SN showed inhibiting effect on the NF-kappaB activity and the expression of the mRNAs of TNF-alpha and IL-1beta in AA rats in a concentration-dependent manner (P<0.05). Positive correlations were found between changes of NF-kappaB activity and expression of TNF-alpha mRNA and IL-1beta mRNA (P<0.01). IkappaB-alpha protein level was increased by various dosages of SN in comparison with control group (P<0.01). In conclusion, SN decreases the mRNA expression of TNF-alpha and IL-1beta by inhibiting the NF-kappaB binding activity, which is mediated through up-regulating the IkappaB-alpha expression of PMs and synoviocytes in AA rats.

Animals↗
PubMed2005

Experimental study on the role of endotoxin in the development of hepatopulmonary syndrome.

AIM: To evaluate the role of intestinal endotoxemia in the genesis of hepatopulmonary syndrome. METHODS: A rat model of cirrhosis was prepared with the method of compound factors. At the end of the eighth week, rats with cirrhosis were treated with 300 microg LPS/100 g body weight, and 1 g/rat of glycine about four h prior to LPS. After three h of LPS treatment, blood and tissues were collected for various measurements. Kupffer cells were isolated from male Wistar rats and cultured, and divided into five groups. Supernatant was harvested at 3 h after treatment with LPS for measurement of tumor necrosis factor-alpha (TNF-alpha). RESULTS: Our results showed that in rats with cirrhosis, slowed and deepened breath with occasional pause was. PaO2, PaCO2 and standard bicarbonate (SB) in arterial blood were decreased. Arterial O2 and actual bicarbonate (AB) were markedly decreased. There was a close correlation between decreased O2 and endotoxin. Metabolic acidosis accompanying respiratory alkalosis was the primary type of acid-base imbalance. The alveolar-arterial oxygen gradient was sharply widened. Massive accumulation of giant macrophages in the alveolar spaces and its wall and widened alveolar wall architecture were observed. The number of bacterial translocations in mesenteric lymph nodes increased. The ratio of TC99M-MAA brain-over-lung radioactivity rose. Endotoxin, and TNF-alpha, endothelin-1 (ET-1), nitric oxide (NO) in plasma and ET-1, carbon monoxide (CO) in lung homogenates increased. After administration of a given dosage of LPS in rats with cirrhosis, various pathological parameters worsened. Plasma level of endotoxin was related to TNF-alpha, ET-1, NO in plasma and ET-1, NO, CO in lung homogenates. TNF-alpha level was related to ET-1 and NO in plasma and lung homogenates and CO in lung homogenate as well. The level of TNF-alpha increased after infusion of LPS into culture supernatant of Kupffer cells in vitro. However, TNF-alpha significantly decreased after pretreatment with glycine, PD98059 and SB212850. Glycine could antagonize the effect of LPS in vivo and in vitro. CONCLUSION: Intestinal endotoxemia accompanying by cirrhosis may be an important mechanism in the development of hepatopulmonary syndrome in rats. Overproduction of TNF-alpha due to endotoxin stimulation of Kupffer cells via mitogen-activated protein kinase (MAPK) signal transduction pathway may be a major mechanism mediating the pathologic alterations of hepatopulmonary syndrome.

Acid-Base Imbalance↗
PubMed2005

Molecular spectroscopic study on the interaction of tetracyclines with serum albumins.

A molecular spectroscopic investigation of the interaction between tetracyclines antibiotics and human serum albumin or bovine serum albumin was reported. The influences of some metal ions on the interaction were also studied. When tetracyclines drugs were added into the solution containing serum albumins, the fluorescence intensity of serum albumins decreased with the increasing of the drugs concentrations, which is due to the formation of new non-fluorescence complexes of drug-serum albumin. The tetracyclines acted as quenchers and quenched the fluorescence of the serum albumins. The binding constants and the number of the binding sites of the reaction of tetracyclines and serum albumins were obtained. The main sorts of acting force between the drugs and serum albumins were found and the action distances and the energy transfer efficiencies between donor-acceptor were calculated based on the Foster energy transference.

Animals↗
PubMed2005

Spectroscopic characterization of effective components anthraquinones in Chinese medicinal herbs binding with serum albumins.

The interactions of serum albumins such as human serum albumin (HSA) and bovine serum albumin (BSA) with emodin, rhein, aloe-emodin and aloin were assessed employing fluorescence quenching and absorption spectroscopic techniques. The results obtained revealed that there are relatively strong binding affinity for the four anthraquinones with HSA and BSA and the binding constants for the interactions of anthraquinones with HSA or BSA at 20 degrees C were obtained. Anthraquinone-albumin interactions were studied at different temperatures and in the presence of some metal ions. And the competition binding of anthraquinones with serum albumins was also discussed. The Stern-Volmer curves suggested that the quenching occurring in the reactions was the static quenching process. The binding distances and transfer efficiencies for each binding reactions were calculated according to the Föster theory of non-radiation energy transfer. Using thermodynamic equations, the main action forces of these reactions were also obtained. The reasons of the different binding affinities for different anthraquinone-albumin reactions were probed from the point of view of molecular structures.

Anthraquinones↗
PubMed2005

Positive association of heparanase expression with tumor invasion and lymphatic metastasis in gastric carcinoma.

Tumor invasion and metastasis are the most common causes of death in gastric carcinoma. Human heparanase influences tumor invasiveness and angiogenesis. Analysis of its expression in gastric carcinoma has been hindered by our inability to procure pure cancer cells from heterogeneous tissue. In the present study, we analyzed heparanase expression in human primary and metastatic gastric carcinoma cells as well as in paired normal gastric epithelial cells by laser capture microdissection coupled with reverse transcription-polymerase chain reaction (RT-PCR). Tumor tissues, metastatic lymph nodes, and apparently uninvolved normal gastric tissues were collected from 30 patients who had undergone gastrectomy with radical lymph node dissection for gastric carcinoma without preoperative treatment. Bulk tissues and laser capture microdissected cell groups were separately subjected to RT-PCR analysis with heparanase-specific primers. For bulk tissues, heparanase-specific transcripts were detectable in all primary tumor tissues, metastatic lymph nodes, and almost all matching normal tissues. RT-PCR analysis after laser capture microdissection showed no detectable heparanase expression in matching normal epithelial cell groups. Of the laser capture microdissected primary gastric carcinoma cells, 47% (14/30) were heparanase positive. Expression was closely associated with greater tumor invasiveness, including Borrmann gross type and depth of wall infiltration. For metastatic cell groups dissected from lymph nodes, 95% showed clear heparanase expression. Furthermore, the extent of lymphatic spread was directly correlated to heparanase expression at the primary site. In conclusion, laser capture microdissection coupled with RT-PCR is a reliable approach for molecular analysis of heparanase expression in gastric carcinoma. Heparanase may facilitate invasion and metastasis of gastric carcinoma cells.

Adult↗
PubMed2005

The dark side of green fluorescent protein.

Here, severe interference of chlorophyll with green fluorescent protein (GFP) fluorescence is described for medicago (Medicago truncatula), rice (Oryza sativa) and arabidopsis (Arabidopsis thaliana). This interference disrupts the proportional relationship between GFP content and fluorescence that is intrinsic to its use as a quantitative reporter. The involvement of chlorophyll in the loss of GFP fluorescence with leaf age was shown in vivo, by the removal of chlorophyll through etiolation or by ethanol extraction, and in vitro, by titration of a GFP solution with chlorophyll solutions of various concentrations. A substantial decrease in fluorescence in early development of medicago and rice leaves correlated with chlorophyll accumulation. In all three species tested, removal of chlorophyll yielded up to a 10-fold increase in fluorescence. Loss of GFP fluorescence in vitro was 4-fold greater for chlorophyll b than for chlorophyll a. Differences exist between plant species for the discrepancy between apparent GFP fluorescence and its actual level in green tissues. Substantial errors in estimating promoter activity from GFP fluorescence can occur if pigment interference is not considered.

Arabidopsis↗
PubMed2005

[Study on therapeutic effects of metformin on rat fatty livers induced by high fat feeding].

OBJECTIVES: To explore the therapeutic effects of metformin on rat fatty livers induced by high fat feeding. METHODS: A fatty liver model was established by feeding rats with a high caloric laboratory chow for 12 weeks, then the rats were randomly divided into three groups, i.e. model control group, metformin group and dietary treatment group. A normal control group was organized at the same time. The rats of the metformin group were given metformin 156 mg/kg/d while the other groups were given distilled water of the same volume by stomach feeding. The model control group rats were fed with high caloric laboratory chow while other groups were fed a normal diet. After four weeks, all the animals were sacrificed. Liver index (liver/body weight ratio), serum activities of liver-associated enzymes, blood lipids, liver triglycerides, fasting blood glucose, fasting plasma insulin, HOMA insulin resistance index (HOMA-IR), and the liver histology of rats of all groups were assayed. RESULTS: The body weight, liver index, serum activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma glutamyl transferase (GGT), total cholesterol (TC), triglycerides (TG) and liver triglycerides in the model group increased significantly, while HDL-cholesterol concentration decreased significantly. Fasting blood glucose, fasting plasma insulin and HOMA-IR showed an increasing tendency, but there was no significant difference of those indexes among the three groups. The liver histology in the model group showed moderate to severe steatosis, mainly as macro vesicle steatosis, lobular inflammatory, cell infiltration and necrosis. Compared with the model group, the levels of body weight, liver index, serum ALT, ALP, TC, TG and liver triglycerides in the metformin group were significantly lower and were similar to those of the normal group, while their HDL-cholesterol concentration was significantly higher. The liver histology in the metformin group was nearly normal. In the dietary treatment group, hyperlipidemia persisted, although liver index and GGT were lower and the liver histology changes were somewhat milder. CONCLUSION: It is suggestive that metformin might be effective in treating rat fatty liver induced by high fat feeding.

Animals↗