Search PubMed⌕ Search

Biomedical subjects

Lei Wang

Publications and source records attributed to Lei Wang.

At least 109 records · Page 6Linked to original sources
PubMed2006

A primary sodium pump gene of the moderate halophile Halobacillus dabanensis exhibits secondary antiporter properties.

The primary sodium pump has been proved to be involved in Na(+) extrusion of bacteria. In our present study, a novel gene encoding a putative primary sodium pump was cloned from chromosomal DNA of moderate halophile Halobacillus dabanensis D-8 by functional complementation, which expression resulted in the growth of antiporter-deficient Escherichia coli strain KNabc in the presence of 0.2 M NaCl. The gene was sequenced and designated nap. The deduced amino acid sequence of Nap has 56% identity to NADH dehydrogenase of Bacillus cereus and 55% to NADH oxidase of Bacillus halodurans C-125. E. coli KNabc carrying nap exhibited resistance to uncoupler CCCP (carbonyl-cyanide m-chlorophenylhydrazone). Everted membrane vesicles prepared from E. coli KNabc carrying nap exhibited secondary Na(+)/H(+) antiporter activity, and nap also supported the growth of respiratory-deficient E. coli ANN0222 lacking NADH dehydrogenase. Based on these results, we proposed that Nap possessed both characteristics of secondary Na(+)/H(+) antiporter and primary sodium pump.

Amino Acid Sequence↗
PubMed2006

Breast conservative therapy in east part of China: a retrospective cohort study.

PURPOSE: To compare the effects of breast conservative therapy (BCT) with modified radical mastectomy (MRM) in women with early stage breast cancer in the east part of China. We conducted a matched retrospective cohort study using data on patients derived from a prospectively collected breast cancer database. METHODS: We used the database that included patients who received MRM or BCT from 1995 to 2002 in our hospital. The match was conducted according to four variables: age at diagnosis, axillary lymph node status, hormone receptor status, and the dimension of tumor. The match ratio was 1:2. MRM group were patients who received MRM treatment (n=254). BCT group were patients who received BCT treatment (n=127). Median follow-up time for the BCT group and MRM group were 58 and 49 months, respectively. The differences of incidence of loco-regional recurrence, disease free survival, and overall survival at 5 years were compared. RESULTS: There were no significant differences in incidence of loco-regional recurrence, DFS and OS at 5 years between the two groups of patients. The incidence of loco-regional recurrence was 1.84% in MRM group and 3.39% in BCT group (P=0.55). The DFS in MRM and BCT patients were 91.57 and 86.04% (P=0.37); the OS in MRM and BCT patient were 97.57 and 96.73% (P=0.66). CONCLUSIONS: For appropriate breast cancer patients, classic lumpectomy plus axillary dissection and postoperative radiotherapy lead to excellent local control and good survival rate in our study. The BCT can result in the same effects as MRM in Chinese breast cancer patients with better cosmetic appearances.

Breast Neoplasms↗
PubMed2006

Increased hematopoietic stem cell mobilization in aged mice.

Hematopoietic stem and progenitor cells (HSPCs) are located in the bone marrow in close association with a highly organized 3-dimensional structure formed by stroma cells, referred to as the niche. Mobilization of HSPCs from bone marrow to peripheral blood in response to granulocyte colony-stimulating factor (G-CSF) requires de-adhesion of HSPCs from the niche. The influence of aging of HSPCs on cell-stroma interactions has not been determined in detail. Using a mouse model of G-CSF-induced mobilization, we demonstrated that the ability to mobilize hematopoietic stem cells is approximately 5-fold greater in aged mice. Competitive mobilization experiments confirmed that enhanced mobilization ability was intrinsic to the stem cell. Enhanced mobilization efficiency of primitive hematopoietic cells from aged mice correlated with reduced adhesion of hematopoietic progenitor cells to stroma and with elevated levels of GTP-bound Cdc42. These results might indicate that stroma-stem cell interactions are dynamic over a lifetime and result in physiologically relevant changes in the biology of primitive hematopoietic cells with age.

Aging↗
PubMed2006

Matrix metalloproteinase 2 (MMP2) and MMP9 secreted by erythropoietin-activated endothelial cells promote neural progenitor cell migration.

We investigated the hypothesis that endothelial cells activated by erythropoietin (EPO) promote the migration of neuroblasts. This hypothesis is based on observations in vivo that treatment of focal cerebral ischemia with EPO enhances the migration of neuroblasts to the ischemic boundary, a site containing activated endothelial cells and angiogenic microvasculature. To model the microenvironment within the ischemic boundary zone, we used a coculture system of mouse brain endothelial cells (MBECs) and neural progenitor cells derived from the subventricular zone of the adult mouse. Treatment of MBECs with recombinant human EPO (rhEPO) significantly increased secretion of matrix metalloproteinase 2 (MMP2) and MMP9. rhEPO-treated MBEC supernatant as conditioned medium significantly increased the migration of neural progenitor cells. Application of an MMP inhibitor abolished the supernatant-enhanced migration. Incubation of neurospheres alone with rhEPO failed to increase progenitor cell migration. rhEPO activated phosphatidylinositol 3-kinase/Akt (PI3K/Akt) and extracellular signal-regulated kinase (ERK1/2) in MBECs. Selective inhibition of the PI3K/Akt and ERK1/2 pathways significantly attenuated the rhEPO-induced MMP2 and MMP9, which suppressed neural progenitor cell migration promoted by the rhEPO-activated MBECs. Collectively, our data show that rhEPO-activated endothelial cells enhance neural progenitor cell migration by secreting MMP2 and MMP9 via the PI3K/Akt and ERK1/2 signaling pathways. These data demonstrate that activated endothelial cells can promote neural progenitor cell migration, and provide insight into the molecular mechanisms underlying the attraction of newly generated neurons to injured areas in brain.

Animals↗
PubMed2006

[Clinical value of videomediastinoscopy in diagnosis of mediastinal disease].

OBJECTIVE: To evaluate the role of videomediastinoscopy in the diagnosis of disease of the mediastinum. METHODS: We retrospectively reviewed the clinical records of the 115 patients who underwent videomediastinoscopy. Local anesthesia or general anesthesia was employed. This operation consisted of cervical videomediastinoscopy in 102 patients, parasternal videomediastinoscopy in 13 patients, ninety-one patients had videomediastinoscopy for diagnosis of isolated mediastinal mass or lymphadenopathy, 25 patients with non small cell lung cancer or suspected lung cancer showed enlarged mediastinal lymph nodes radiographically in the chest. RESULTS: Among the patients with mediastinal disease, sarcoidosis was diagnosed in 37 patients, tuberculosis in 14 patients, lymphoma in 15 patients, nodal metastasis in 18 patients, noncaseating granulomata without classical "sarcoid" in 6 patients, with the accuracy of 93.3% (84/90); and staging of lung cancer in 25 patients, with the accuracy of 100% (25/25). The total accuracy of videomediastinoscoy and CT was 94.8% (109/115), 56.5% (65/115), respectively. Mean operative time was 26 min. There was neither complication nor mortality. CONCLUSION: videomediastinoscopy is a safe and effective procedure for the diagnosis of mediastinal disease and the staging of lung cancer.

Adolescent↗
PubMed2006

Clonal analysis of palmar fibromatosis: a study whether palmar fibromatosis is a real tumor.

BACKGROUND: Palmar fibromatosis that arises in the palmar soft tissue is characterized by infiltrative growth with a tendency toward local recurrence but does not metastasize. This study investigated the clonality of this process in twelve female patients, each with a single lesion, by examining the pattern of X-chromosome inactivation. METHODS: Hematoxylin and eosin stained sections of formalin-fixed, paraffin-embedded tissues were microdissected by laser capture microdissection to obtain the proliferative spindle cells. Tumor cells were isolated from the sections of rectum adenocarcinoma, and used for positive control. The genomic DNAs was extracted with phenol-chloroform, digested with a methylation-sensitive restriction endonuclease HpaII, and amplified by polymerase chain reaction (PCR), using primers targeted to a highly polymorphic short tandem repeat (STR) of the human androgen receptor gene (HUMARA). RESULTS: Among the twelve samples, three samples failed amplification, one sample showed homozygosity which was not suitable for further analysis, eight samples were successfully amplified, and showed a random X chromosome inactivation pattern, suggesting polyclonality of these lesions. CONCLUSION: The current findings suggest that palmar fibromatosis is a reactive proliferation rather than a clonal neoplasm.

Journal Article↗
PubMed2006

Synaptic proteins and phospholipids are increased in gerbil brain by administering uridine plus docosahexaenoic acid orally.

The synthesis of brain phosphatidylcholine may utilize three circulating precursors: choline; a pyrimidine (e.g., uridine, converted via UTP to brain CTP); and a PUFA (e.g., docosahexaenoic acid); phosphatidylethanolamine may utilize two of these, a pyrimidine and a PUFA. We observe that consuming these precursors can substantially increase membrane phosphatide and synaptic protein levels in gerbil brains. (Pyrimidine metabolism in gerbils, but not rats, resembles that in humans.) Animals received, daily for 4 weeks, a diet containing choline chloride and UMP (a uridine source) and/or DHA by gavage. Brain phosphatidylcholine rose by 13-22% with uridine and choline alone, or DHA alone, or by 45% with the combination, phosphatidylethanolamine and the other phosphatides increasing by 39-74%. Smaller elevations occurred after 1-3 weeks. The combination also increased the vesicular protein Synapsin-1 by 41%, the postsynaptic protein PSD-95 by 38% and the neurite neurofibrillar proteins NF-70 and NF-M by up to 102% and 48%, respectively. However, it had no effect on the cytoskeletal protein beta-tubulin. Hence, the quantity of synaptic membrane probably increased. The precursors act by enhancing the substrate saturation of enzymes that initiate their incorporation into phosphatidylcholine and phosphatidylethanolamine and by UTP-mediated activation of P2Y receptors. Alzheimer's disease brains contain fewer and smaller synapses and reduced levels of synaptic proteins, membrane phosphatides, choline and DHA. The three phosphatide precursors might thus be useful in treating this disease.

Administration, Oral↗
PubMed2006

In vitro panning of a targeting peptide to hepatocarcinoma from a phage display peptide library.

Phage display technology has been used as a powerful tool in the discovery of ligands specific to receptor(s) on the surface of a cancer cell and could also impact clinical issues including functional diagnosis and cell-specific drug delivery. After three rounds of in vitro panning and two rounds of reverse absorption, a group of phages capable of addressing BEL-7402 enormously were obtained for further analysis. Through a cell-based ELISA, immunofluorescence, FACS, and in vivo binding study, WP05 (sequence TACHQHVRMVRP) was demonstrated to be the most effective peptide in targeting four kinds of liver cancer cell lines (BEL-7402, BEL-7404, SMMC-7721, and HepG2), but not the normal liver cell line HL-7702. In conclusion, the peptide WP05 which was screened by in vitro phage display technology was proved to be a targeting peptide to several common hepatocellular carcinoma cell lines.

Amino Acid Sequence↗
PubMed2006

Defective expression of Galpha12 in the testes of azoospermia patients and in the spermatozoa with low motility.

Antibody to the Galpha12-subunit of guanine nucleotide regulatory proteins was used to determine whether the Galpha12 is present in adult human spermatogenic cells and to determine its role in dyszoospermia. Immunoblots from testes and spermatozoa demonstrated the presence of Galpha12 in the samples. Immunohistochemical analyses of testes found that Galpha12 was expressed in the cytoplasm of Leydig cells and was expressed in spermatids from the elongating Sb phase to mature sperm. Indirect immunofluorescence of human spermatozoa revealed the presence of Galpha12 in the neck region and the midpiece of the sperm. Galpha12 in spermatids and spermatozoa partially co-localized with F-actin and alpha-tubulin. Immunohistochemical analyses of tissues from three patients with non-obstructive azoospermia showed abnormal expression of Galpha12 in more than 45% of spermatids. Furthermore, Western blots and indirect immunofluorescence found defective expression of Galpha12 in low-motility spermatozoa with midpieces that were bent on themselves. Therefore, it suggests that Galpha12 plays a role in polarity and tail formation as spermatids mature. Furthermore, Galpha12 may be a candidate protein responsible for azoospermia caused by spermatogenic disturbance or midpiece deformities.

Actins↗
PubMed2006

Genetic polymorphisms and susceptibility to lung disease.

Susceptibility to infection by bacterium such as Bacillus anthracis has a genetic basis in mice and may also have a genetic basis in humans. In the limited human cases of inhalation anthrax, studies suggest that not all individuals exposed to anthrax spores were infected, but rather, individuals with underlying lung disease, particularly asthma, sarcoidosis and tuberculosis, might be more susceptible. In this study, we determined if polymorphisms in genes important in innate immunity are associated with increased susceptibility to infectious and non-infectious lung diseases, particularly tuberculosis and sarcoidosis, respectively, and therefore might be a risk factor for inhalation anthrax. Examination of 45 non-synonymous polymorphisms in ten genes: p47phox (NCF1), p67phox (NCF2), p40phox (NCF4), p22phox (CYBA), gp91phox (CYBB), DUOX1, DUOX2, TLR2, TLR9 and alpha 1-antitrypsin (AAT) in a cohort of 95 lung disease individuals and 95 control individuals did not show an association of these polymorphisms with increased susceptibility to lung disease.

California↗
PubMed2006

Isolation and characterization of a novel thermophilic Bacillus strain degrading long-chain n-alkanes.

A thermophilic Bacillus strain NG80-2 growing within the temperature range of 45-73 degrees C (optimum at 65 degrees C) was isolated from a deep subterranean oil-reservoir in northern China. The strain was able to utilize crude oil and liquid paraffin as the sole carbon sources for growth, and the growth with crude oil was accompanied by the production of an unknown emulsifying agent. Further examination showed that NG80-2 degraded and utilized only long-chain (C15-C36) n-alkanes, but not short-chain (C8-C14) n-alkanes and those longer than C40. Based on phenotypic and phylogenic analyses, NG80-2 was identified as Geobacillus thermodenitrificans. The strain NG80-2 may be potentially used for oily-waste treatment at elevated temperature, a condition which greatly accelerates the biodegradation rate, and for microbial enhancing oil recovery process.

Alkanes↗
PubMed2006

Effect of Chinese medicine Qinggan Huoxuefang on inducing HSC apoptosis in alcoholic liver fibrosis rats.

AIM: To investigate the effect of Qinggan Huoxuefang (QGHXF) on improvement of liver function and pathology in rats, and to analyze the mechanism. METHODS: Wistar rats were divided into three groups at random: normal control group (12),micro-amount carbon tetrachloride group (CCl(4))(12) and model group A (60). The model group A was ingested with the mixture (500 mL/L alcohol, 8 mL/kg per day; corn oil, 2 mL/kg per day; pyrazole, 24 mg/kg per day) once a day and intraperitoneal injections of 0.25 mL/kg of a 250 mL/L solution of CCl(4) in olive oil twice a week for 12 wk. The CCl(4) group received intraperitoneal injections only. At the end of 8 wk the model group A (60) was divided into 5 subgroups: model group, Xiaochaihu Chongji (XCH) group, QGHXF high dose group, moderate dose group and low dose group, and were given the drugs respectively. At the end of 12 wk, all the rats were killed and blood samples collected, as well as liver tissue. Blood samples were used for evaluation of alanine transaminase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyltransferase (gamma-GT). Liver specimens were obtained for routine HE, apoptosis gene array and flow cytometry analysis. RESULTS: A liver fibrosis animal model was successfully established. Fibrosis was obviously reduced in QGHXF high dose group, and no fibrosis formed in CCl(4) group. Compared with model group the QGHXF group and XCH group could obviously decrease the level of ALT, AST, ALP, and GGT (P<0.05). QGHXF high dose group was better than XCH group in ALT (615+/-190 vs 867+/-115), and AST(1,972+/-366 vs 2,777+/-608). Moreover, QGHXF could reduce liver inflammation, fibrosis-induced hepatic stellate cell (HSC) apoptosis and regulate apoptosis gene expression. The HSC apoptosis rates of QGHXF groups were 22.4+/-3.13, 13.79+/-2.26 and 10.07+/-1.14, higher than model group, 6.58+/-1.04 (P<0.05). Compared to model group, 39 genes were up-regulated, 11 solely expressed and 17 down-regulated in high dose group. CONCLUSION: QGHXF can improve liver fibrosis and induce HSC apoptosis.

Animals↗
PubMed2006

Reverse of NK cytolysis resistance of type II cytokine predominant-human tumor cells.

Tumor cells suppress host immunity by secreting soluble factors, among which cytokines play important roles. Type I cytokine mRNA levels (IL-2 and IFNgamma) and type II cytokine mRNA levels (IL-4, IL-10 and IL-13) of twenty tumor cell lines and fresh tumor tissues from fifteen patients with colorectal cancer were examined by RT-PCR method. Upon analysis, tumor cells showed type II predominance and were resistant to NK cytolysis. In order to reverse the type II predominant status, type I cytokines (IL-2 or IFNgamma) and/or anti-type II cytokine antibody (IL-10 mAb) were used in an in vitro study. By this shifting treatment, type II cytokine mRNA levels of these tumor cells were decreased, moreover, the sensitivity to natural cytolysis of these cells was then significantly increased. Thus, tumor-induced type II cytokine dominance is possibly to be shifted into type I status, which benefits the anti-tumor natural immunity.

Adenocarcinoma↗
PubMed2006

Highly stable chiral cadmium 1,2,4-benzenetricarboxylate: synthesis, structure, and NLO and fluorescence properties.

Employing an unsymmetrical 1,2,4-benzenetricarboxylate as a bridging ligand, a new 3-D chiral cadmium coordination polymer [Cd(2)(OH)(1,2,4-BTC)] (1,2,4-BTC = 1,2,4-benzenetricarboxylate) has been prepared under hydrothermal conditions and characterized by single crystal X-ray diffraction. This compound crystallizes in the orthorhombic space group P2(1)2(1)2(1), with cell parameters a = 6.900(2) A, b = 7.404(3) A, c = 19.116(5) A, V = 976.5(5) A(3), and Z = 4. Its structure contains 2-D Cd-O-Cd connectivity, which is further linked by the 1,2,4-BTC ligand into a 3-D supramolecular framework. The 1,2,4-BTC ligand shows a novel and unprecedented coordination mode: nine bonds to eight metals with each carboxylate as a tridentate group. The compound exhibits intense photoluminescence at room temperature and shows distinct NLO properties. On the basis of the results of TG/DTA analyses, the structure is thermally stable up to approximately 380 degrees C.

Journal Article↗
PubMed2006

[Resection for lung cancer invading the superior vena cava].

OBJECTIVE: To analyze the feasibility and the value of resection for lung cancer invading the superior vena cava (SVC). METHODS: Between 1988 and 2005 the data of 31 patients who underwent resection were analyzed retrospectively. The reconstruction was done using simple suture, pericardial patch or prosthetic replacement. Postoperative morbidity, long-term survival were examined using the Kaplan-Meier method (Log rank test) and the COX model for survival. RESULTS: Seventeen squamous cell carcinomas, 8 adenocarcinomas, and 6 undifferentiated small cell carcinomas were resected. There were 13 partial SVC resection, the reconstruction was done using a simple running in 5 patients, and a pericardial patch in 8 patients. Eighteen patients underwent complete resection of SVC with prosthetic replacement. The time of clamping the SVC system was from 8 to 35 minutes for complete resection patients, while the time was from 3 to 15 minutes for partial resection patients. One patient didn't clamp the SVC. Postoperative morbidity and mortality were 48% and 0%, respectively. One, 3 and 5-year survival rates were 61%, 33% and 21%, respectively, with median survival at 31 months. Survival rate of patients with N2 disease was obviously lower than those with localized (N0/N1) nodal disease (chi2 = 14.3, P = 0.000), the median survival was 42 and 13 months respectively. There were no significant effects on overall survival with pathologic features and surgery methods. Survival rate of patients with induction chemotherapy before operation or intraoperative chemotherapy was higher than those received direct surgery (chi2 = 5.0, P = 0.025), the median survival was 39 and 14 months respectively. CONCLUSIONS: The resection of the SVC for involvement by lung cancer can be performed in selected patients, especially for those with localized (N0/N1) nodal disease. Induction chemotherapy should be performed.

Adult↗
PubMed2006

Ischemic cerebral tissue response to subventricular zone cell transplantation measured by iterative self-organizing data analysis technique algorithm.

To investigate the changes of the ischemic lesion in rat brain after subventricular zone (SVZ) cell transplantation and the influence of the grafted cells on the appearance of angiogenesis, SVZ cells, superparamagnetically labeled, were intracisternally transplanted into the rat brain 48 h after onset of embolic stroke. A complete set of magnetic resonance (MR) images was acquired for all animals with (n=8) and without (n=3) cell grafting at approximately 24 h, 72 h, and weekly for 6 weeks after stroke. Transplanted cells were tracked by high-resolution three-dimensional gradient-echo images and the interaction between the cells and ischemic lesion was detected by ISODATA (Iterative Self-Organizing Data Analysis Technique Algorithm) calculated from T(1), T(2) and T(1sat) maps. Tissue status from ISODATA was characterized by a specific signature, which represents the deviation from normal tissue in the feature space. Transplanted SVZ cells selectively migrated towards the ischemic side of the rat brain and approached the lesion boundary within 1-week after grafting. Cell treated rats exhibited a significant reduction of average lesion size compared with control rats (P<0.05). A significant reduction of tissue signature (P<0.001) induced by cell transplantation was localized to the position of grafted cells, and these sites exhibited stably restored cerebral blood flow (CBF) (approximately 85% of normal CBF). Angiogenesis was present in sites either immediately adjacent to or surrounded by the grafted cells. Our data indicate that map-ISODATA accurately and dynamically characterizes the ischemic lesion and its response to cell therapy.

Algorithms↗
PubMed2006

Determination of furfural in an oscillating chemical reaction using an analyte pulse perturbation technique.

A rapid and convenient method for the determination of furfural is presented that is based upon sequential perturbation of the Mn(II)-catalyzed B-Z oscillating system with different amounts of furfural using a continuous-flow stirred tank reactor (CSTR). When the sample was injected, the change in the amplitude and/or period was linearly proportional to the logarithm of the concentration of furfural over the range 3 x 10(-8) approximately 1 x 10(-5) mol L(-1). This method gave a detection limit of 3 x 10(-9) mol L(-1) under optimum conditions. Finally, the possible mechanism of furfural perturbation in the oscillating reaction is discussed. When the furfural was injected into the Mn(II)-catalyzed B-Z oscillating system, the change in the amplitude and/or period was linearly proportional to the logarithm of the concentration of furfural over the range 3 x 10(-8)~1 x 10(-5) mol L(-1), with a detection limit of 3 x 10(-9) mol L(-1) under optimum conditions.

Journal Article↗