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Biomedical subjects

L Xu

Publications and source records attributed to L Xu.

At least 289 records · Page 16Linked to original sources
PubMed2000

Correlation of Glut-1 glucose transporter expression with.

Positron emission tomography (PET) with [18F]2-fluoro-2-deoxy-D-glucose (FDG) may show negative results for bronchioloalveolar lung carcinoma. We investigated the correlation of Glut-1 glucose transporter expression with [18F]FDG uptake in non-small cell lung cancer. Thirty-two patients with 34 non-small cell lung cancers (7 bronchioloalveolar carcinomas, 23 non-bronchioloalveolar adenocarcinomas, 3 squamous cell carcinomas, and 1 adenosquamous cell carcinoma) were studied. Final diagnoses were established by histology (via thoracotomy) in all patients. [18F]FDG PET was performed 40 min after i.v. injection of 185 MBq [18F]FDG. For semi-quantitative analysis of [18F]FDG uptake, standardized uptake values (SUVs) were calculated. Glut-1 expression was studied in terms of the immunohistochemistry of paraffin sections using anti-Glut-1 antibody to determine the intensity (0-3) of Glut-1 immunoreactivity and percentage of the Glut-1-positive area. Of seven bronchioloalveolar carcinomas, six (85.7%) were negative for the expression of Glut-1, while only one (4.3%) of 23 non-bronchioloalveolar adenocarcinomas was negative (P < 0.0001). The percentages of Glut-1-positive area, as well as the SUVs, were significantly lower in bronchioloalveolar carcinomas (n = 7) (2.86% +/- 7.56% and 1.25 +/- 0.75, respectively) than in non-bronchioloalveolar adenocarcinomas (n = 23) (54.83% +/- 25.64%, P < 0.0001, and 3.94 +/- 1.93, P = 0.001, respectively). The degree of cell differentiation correlated with the percentage of Glut-1-positive area and SUVs in adenocarcinoma of the lung. Correlations between SUVs and the intensity of Glut-1 immunoreactivity were also significant (intensities 0 and 1, n = 11, SUV 1.47 +/- 0.63; intensities 2 and 3, n=23, SUV 4.78 +/- 2.13; P < 0.0001). The percentage of Glut-1-positive area correlated significantly with SUVs (n = 34, r = 0.658, P < 0.01). Overexpression of Glut-1 correlated with high [18F]FDG uptake. These findings suggest that Glut-1 expression is related to [18F]FDG uptake in non-small cell lung cancer. Glut-1 expression, as well as [18F]FDG uptake, correlated with the degree of cell differentiation in adenocarcinomas, and both Glut-1 expression and [18F]FDG uptake were significantly lower in bronchioloalveolar carcinomas than in non-bronchioloalveolar carcinomas.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed2000

[The effect of melatonin on enhancing immune function and inhibiting the ability of NO over-release in morphine dependent mice].

AIM: To observe the effects and mechanism of melatonin (MT) on the immune function of morphine dependent mice. METHODS: A physical dependent mice model was established by repeated subcutaneous injection of morphine. The intensity of morphine withdrawal syndrome was evaluated according to the weight of immune organs, the proliferation reaction of stimulated splenic lymphocytes by Con A, the phagoindex of blood primed macrophages and the content of NO induced in the peritoneal macrophage (pM phi). RESULTS: MT reversed the inhibitory effect of morphine on the proliferation ability of splenic lymphocytes and enhanced the phagocytosis of macrophages of morphine dependent mice obviously and prevented the over-release of NO from pM phi. The enhancing effects of MT on the phagocytosis can be prevented by naloxon. CONCLUSION: MT can significantly enhance the immune function of morphine dependent mice and inhibit NO excessive release from pM phi.

Adjuvants, Immunologic↗
PubMed2000

Comparative study on efficacy of three sperm-separation techniques.

AIM: To evaluate the comparative effectiveness of real-time sperm separation technique (Wang's tube method) and other two conventional methods in isolating high-quality sperm preparation, and to compare the spouse pregnancy rate in intrauterine insemination (IUI) with sperm preparations isolated by these methods. METHODS: The effectiveness of the real-time sperm separation technique, the conventional swim-up and the Percoll discontinuous density gradient methods in isolating sperm preparations from 60 infertile patients (20 with apparently normal semen and 40, abnormal semen contaminated with microorganisms and other impurities) was evaluated and compared. The microorganisms to be removed included bacteria, virus, Chlamydia trachomaticum, Ureaplsama urealyticum, etc. The spouse pregnancy rates in IUI with sperm preparations isolated by these three techniques from 80 oligoasthenoteratospermic patients were also compared. RESULTS: The quality (including the percentages of normal form, normal-chromatin and motile sperm, and the grade of motility) of sperm obtained by the real-time sperm separation technique was much higher (P < 0.01) as compared with those by the other two methods. The Wang's tube method was also more effective in removing microorganisms and other impurities. The method provided a higher IUI pregnancy rate than the other two sperm separation techniques (P < 0.05). CONCLUSION: The real-time sperm separation technique is the most effective method so far available in isolating high-quality sperm samples to be used in assisted reproduction.

Adult↗
PubMed2000

[The role of bcl-2 gene family in taxol-mediated apoptosis in BJAB B cell lymphoma cell line].

OBJECTIVE: To study the apoptosis-inducing effect of taxol on BJAB B cell lymphoma cell line and the role of bcl-2 gene family. METHODS: BJAB cells were treated with taxol and examined for morphologic changes under light and electron microscopes. Flow cytometry assays and DNA gel electrophoresis were used to demonstrate changes in nuclear DNA contents and DNA fragmentations. Changes in bcl-2 gene family at mRNA and protein levels were studied by immunohistochemistry and semi-quantitative RT-PCR technique. RESULTS: Taxol inhibited growth of BJAB cells. The cells initially showed G2/M arrest, followed by apoptosis, in a time and dose dependent manner. The expression of bcl-2 at mRNA and protion level was decreased while that of bcl-xs transcription was increased after taxol treatment. CONCLUSION: Taxol induces apoptosis of BJAB cells. Bcl-2 and bcl-xs are involved in the regulation of taxol-induced apoptosis.

Antineoplastic Agents, Phytogenic↗
PubMed2000

Non-viral gene delivery for p53.

Abnormality in the tumor suppressor gene p53 is one of the most common occurrences associated with human neoplasia. Consequently, restoration of wild-type p53 function is seen as a particularly promising approach for cancer gene therapy. In recent years, considerable research effort has centered upon developing and improving non-viral delivery systems as alternatives to viral vectors for gene delivery. These methods include the use of lipoplexes and polyplexes, and even delivery of naked DNA. Optimally effective cancer gene therapy requires treatment of metastatic as well as local disease, and to achieve this end, systemic delivery systems for therapeutic genes will be required. This review will discuss some of the recent advances in ways to improve targeting, transfection efficiency and stability for systemic, non-viral p53 gene therapy.

Animals↗
PubMed2000

Fusion of low-fusing porcelain to Ti-75 alloy: an experimental study.

OBJECTIVE: To study the stomatological feasibility of low-fusing porcelain fused to Ti-75 alloy. METHODS: Electroprobemicroanalysis (EPMA) and shear test were used to observe interface state and bonding strength of porcelaintitanium. RESULTS: Shear bond strengths of low-fusing porcelain with Ti-75 alloy and conventional porcelain each fused to metal (NC-VMK68) were 47.38 +/- 7.95 MPa and 48.50 +/- 7.60 MPa, respectively. There was no significant difference between the shear bonding strength of low-fusing porcelain with Ti-75 and that of conventional porcelain fused to metal (PFM) (P > 0.05). EPMA showed that Ti-75 alloy and low-fusing porcelain bound tightly, had no fissure, and that low-fusing porcelain had good infiltration to Ti-75. It was shown that Ti spread from Ti-75 basal body into porcelain, and elements such as Si-Sn spread from porcelain to Ti-75. CONCLUSION: Ti-75 alloy can be used stomatologically, as a porcelain alloy.

Biocompatible Materials↗
PubMed2000

[Detecting Epstein-Barr virus in nasopharyngeal carcinoma tissue using in situ polymerase chain reaction].

OBJECTIVE: To develop a sensitive non-isotopic method for in situ detection of Epstein-Barr virus (EBV) in paraffin-embedded section of nasopharyngeal carcinoma (NPC) tissue. METHODS: The EBV BamHI-W fragment labeled with digoxigenin as probe was used to perform in situ hybridization and PCR in situ hybridization (in situ PCR). RESULTS: The method of in situ PCR for the detection of EBV in NPC tissue was proved to be much more sensitive than in situ hybridization. CONCLUSION: Hybridization in situ of PCR product is useful to detect EBV in NPC tissues.

Adenocarcinoma↗
PubMed2000

[An experimental study of tooth mesial migration].

OBJECTIVE: To study the mechanism of tooth mesial migration with animal experiment. METHODS: The upper and lower first molars of Wuzhishan miniature pigs were used as experimental teeth. The mesial migration of experimental teeth was calculated and analysed by measuring the models. Fluorescent mark was used and analysed by injecting tetracycline and xvlenol orange, and histological changes were analyzed. RESULTS: The lower teeth migrate mesially 0.14 mm and 1.21 mm during 16 weeks, and the upper teeth migrate mesially 1.36 mm and 2.08 mm during 24 weeks. The distal alveolar bones of experimental teeth had fluorescent bands; alveolar bones of teeth without antagonist teeth reconstructed in vertical direction; the distance between fluorescent bands of lower experimental teeth without antagonist teeth was wider than that of teeth with antagonist teeth. The fluorescent bands formed in both mesial and distal cementum. CONCLUSION: The results don't support the point that transseptal fibre or force of molar eruption makes teeth migrate mesially; the mesial migration of teeth is related with the reconstruction of alveolar bones and the stress distribution in the bones.

Animals↗
PubMed2000

[Clinical and experimental study on effect of Chanbei Kechuanping in treating bronchial asthma].

OBJECTIVE: To observe the clinical effect of Chanbei Kechuanping (CBKCP) on bronchial asthma and to explore its mechanism. METHODS: Ninety-six patients of bronchial asthma were randomly divided into two groups, the CBKCP treated group and the control group (treated by Guilong Kechuanning). The changes on symptoms and signs of asthma, pulmonary function, T-lymphocyte subsets, plasma soluble interleukin-2 receptor (sIL-2R), thromboxane B2(TXB2) and 6-keto-prostaglandin F1 alpha(6-keto-PGF1 alpha) were observed before and after treatment. RESULTS: (1) The markedly effective rate and effective rate in the CBKCP treated group were higher than those in the control group. The pulmonary function, including 1 second forced expiratory volume, maximum expiratory flow rate and forced lung expiratory vital capacity were all improved in both groups, but the effect was more obvious in the CBKCP treated group. (2) As compared with the control group, CBKCP showed more obvious effect in lowering sIL-2R, T-lymphocyte subset and raising 6-keto-PGF1 alpha. Experimental study of guinea pig with asthma model showed that CBKCP could markedly prolong the latent time of asthma attack, lower the percentage of mast cells in total cells in the alveoli lavage solution, blood acidophic cell count and degranulation rate of mast cells, and decrease IgE, IL-4 and TXB2 levels as well as increase the 6-keto-PGF1 alpha level. CONCLUSION: CBKCP has favorable therapeutic effect on asthma attack, it might play the role partly by regulating the functional T-lymphocyte subsets, reducing the level of IgE, sIL-2R, IL-4 and TXB2, and increasing the level of 6-keto-PGF1 alpha.

Adolescent↗
PubMed2000

[The effects of taxol on different types of lymphoma cell lines].

OBJECTIVE: To observe the effects of new anticancer drug taxol on different types of lymphoma cells and to explore the value of its clinical application. METHODS: Inverted microscope, light microscope, electron microscope, FCM and DNA gel electrophoresis were used to observe the effects of taxol on three different types of lymphoma cell lines, including Jurkat (T cell lymphoma), BJAB (B cell lymphoma, EBV negative) and Raji (B cell lymphoma, EBV positive). RESULTS: Taxol can inhibit the growth and induce the apoptosis of all the three cell lines, while different sensitivities and apoptosis extent. Jurkat cells were most sensitive, mainly showing apoptosis; BJAB cells were last sensitive, showing G(2)/M arrest before apoptosis; Raji cells were last sensitive, mainly showing G(2)/M arrest and only part of cells going to apoptosis. CONCLUSION: Taxol is a valuable chemotherapeutic agent for lymphoma. Its sensitivity differed with the types of lymphoma, EBV infection and the extent of induced apoptosis.

Antineoplastic Agents, Phytogenic↗
PubMed2000

[Mimic epitope recognized by monoclonal antibody MG7 against gastric cancer through screening phage displayed random peptide library].

OBJECTIVE: To get mimic peptide epitopes that could be recognized by a monoclonal antibody against gastric cancer named MG7 from random peptide library displayed by phage, and to provide useful information for further study of the interaction between antigen and antibody. METHODS: Through affinity enrichment and immunoscreening of two phage-displayed non-apeptide libraries constructed in pVIII with MG7 MAb separately, several positive phages were obtained. Fluorescence labeling and dot blot were carried out for further identification of their binding activities. Then, some of the positive phages were sequenced and their corresponding peptide sequence was deduced according to their DNA sequence. Finally, HLA binding prediction software was applied for HLA binding analysis. RESULTS: Based on several rounds of screening and binding activity detection, we got twelve and thirty positive phage clones respectively from two libraries. Through DNA sequencing, peptide deducing and sequence aligning analysis of the positive phages, some preserved epitope information such as PLX(0 - 2)S, SAVR, XRMX and YARN were obtained. The prediction using HLA binding analysis software showed that most of the sequenced peptide had the potentiality to bind with HLA molecules. CONCLUSION: PLX(0 - 2)S, SAVR, XRMX and YARN may be some of the motifs which could be recognized by monoclonal antibody MG7.

Antibodies, Monoclonal↗
PubMed2000

[Digital photography and blurred image processing of retinal nerve fiber layer in glaucoma].

OBJECTIVE: Red-free photographs are effective in detecting retinal nerve fiber layer (RNFL). The reasons why it is not used by most clinics are difficulty in laborious developing and blurred image evaluating. To account for getting real-time image and blurred image evaluating, the digital photography and computerized image processing are used. METHODS: RNFL photographs were taken by Nikon Fundus Camera connected with a high resolution digital camera (Kodak) and a green filter. As usual it is necessary to see the texture of RNFL in evaluating its image, but blurred images due to media opacities greatly lose their resolution. The way we used no focus on seeing the texture of RNFL, but on evaluating the distribution pattern of RNFL. RNFL images have more white reflex in temporal superior, temporal inferior, nasal superior and nasal inferior sections around optic disc according to the thickness of RNFL. Threshold segmentation was used, we shift a threshold bar to the position until the nasal or temporal section around optic disc is black with the software Photoshop. RESULTS: In the normal RNFL image, the white reflex was of butterfly pattern, i.e., the temporal superior and temporal inferior sections around optic disc were white. In cases with glaucoma, the characteristic of early damage of optic nerve was the loss of RNFL at the temporal superior and temporal inferior part of the retina, thus the normal butterfly pattern was changed, the temporal superior or/and temporal inferior sections were black. With this method it is more effective to evaluate RNFL. However, in cases with retinal pigment epithelium faint in color and in cases with choroidal defect, it is still difficult to evaluate the distribution of RNFL. CONCLUSIONS: It is an easy and effective way to detect glaucomatous damage with the digital photography and RNFL pattern evaluation.

Glaucoma↗
PubMed2000

[Taxol-induced apoptosis in Jurkat T cell lymphoma cell line and its molecular mechanisms].

OBJECTIVE: To observe whether antimicrotubular drug taxol can induce apoptosis in Jurkat T cell lymphoma cell line and the role of bcl-2 gene family in this process. METHODS: Different concentrations of taxol were used to treat Jurkat cells. Cell morphology was observed under light and electron microscope. Flow cytometry and electrophoresis were used to analyze DNA contents and DNA fragments. bcl-2 gene family proteins and mRNAs were studied by immunohistochemistry and semi-quantitative RT-PCR technique. RESULTS: Taxol could inhibit Jurkat cell growth. Within a certain range of treating time and dose, cells were induced apoptosis with a time and dose related manner. The expressions of bax protein and mRNA were increased and bcl-x(s) mRNA became detectable after taxol treatment. CONCLUSION: Taxol can specifically induce Jurkat cell apoptosis. It might provide a theoretical basis for clinical treatment and a good model for studying apoptotic gene modulation. Bax and bcl-x(s) participate in the taxol induced apoptosis of Jurkat cells.

Antineoplastic Agents, Phytogenic↗
PubMed2000

[Influence of pravastatin on expression of platelet CD(62P) and CD(41) in patients with hypercholesterolemia in vitro and in vivo].

OBJECTIVE: To study in vitro and in vivo effect of hypercholesterolemia (HC) on expression of platelet CD(62P) and CD(41) and their changes after treatment with pravastatin. METHODS: Twenty patients with HC were given 10 - 20 mg/d pravastatin orally for 4 - 8 weeks. Changes of blood cholesterol and expression of platelet CD(62P) and CD(41) were detected by flow cytometry. RESULTS: After 4 and 8 weeks' treatment, blood cholesterol level and platelet aggregation function decreased. The expression of CD(62P) average fluorescence intensity decreased from 31.8 +/- 7.8 to 27.2 +/- 6.9 and 26.8 +/- 4.9; CD(62P) (%) from (31.3 +/- 9.3)% to (26.4 +/- 7.4)% and (25.3 +/- 9.1)% (P < 0.05); CD(41) from 483.2 +/- 263.9 to 348.1 +/- 192.4 and 306.8 +/- 128.0 (P < 0.05), respectively. Similar results were obtained in vitro study. CONCLUSION: Improvement of platelet function and expressions of CD(62P) and CD(41) in HC patients after prevastatin treatment may be resulted from enhancing arteriosclerosis regression. It suggested from the in vitro result that pravastatin might play a direct effect on platelet function.

Adult↗
PubMed2000

[Effect of central administration of motilin on the activity of gastric-related neurons in brain stem and gastric motility of rats].

To investigate the effect of microinjection of motilin into ventral medail hypothalamus (VMH) or intracerebroventricle (icv) on gastric motility, extracellular unit responses of dorsal vagal complex (DVC) in anesthetized rats and gastric motility of conscious rats were recorded. The results are as follows. (1) The firing rate of gastric distention related neurons in DVC was modified. (2) VMH and icv administration of motilin induced obvious enhancement in gastric motility. (3) The effect of motilin on gastric motility was abolished by vagotomy. These results imply that central motilin appears to work as an excitatory neuromodulator in the regulation of gastric motility through VMH-DVC-vagal nerve axis.

Animals↗
PubMed2000

[A transient increase in CCK mRNA levels in amygdala following audiogenic seizures in audiogenic seizure-prone rats].

The effects of single and multiple seizures on cholecystokinin (CCK) mRNA levels in amygdala of audiogenic seizure-prone rats (P77PMC) were examined by in situ hybridization. The main results are as follows: (1) CCK mRNA positive neurons (No/0.01 mm(2)) in amygdala showed a transient increase in number from the 8+/-1 to 58+/-5 (P<0.01) in 30 min and then returned to the control value in 2 h (9+/-2, P>0.05), and (2) in the multiple consecutive seizure rats the increase in 30 min (22+/-3) was less than that in the single seizure rats (P<0.01), and the number returned to normal in 1 h (6+/-1, P>0.05). These data indicate that the transient increase in CCK mRNA level in amygdala following single or multiple consecutive seizures of P77PMC may be involved in anti-convulsant mechanisms in response to acute seizures.

Amygdala↗