PubMed Health⌕ Search

Biomedical subjects

G J Wu

Publications and source records attributed to G J Wu.

At least 19 recordsLinked to original sources
PubMed2004

Bacterial diversity in Malan ice core from the Tibetan Plateau.

Three ice core samples were collected from the Malan ice core drilled from the Tibetan Plateau, and three 16S rDNA clone libraries by direct amplification from the ice-melted water were established. Ninety-four clones containing bacterial 16S rDNA inserts were selected. According to restriction fragment-length polymorphism analysis, 11 clones were unique in the library from which they were obtained and used for partial sequence and phylogenetic analysis, and compared with 8 reported sequences from the same ice core at depth 70 m. Differences among the samples were apparent in clone libraries. The phylotypes were dominated by the Proteobacteria group, Acinetobacter sp. and Cytophaga-Flavobacterium-Bacteroides (CFB) group. They accounted for 92.5% (Proteobacteria), 100% (Acinetobacter sp.), 34.4% (CFB) and 100% (beta-Proteobacteria) in the clone libraries from the samples at ice depths 35, 64, 70, and 82 m, respectively. The Acinetobacter sp. was only found in the deposition at ice depth 82 m and closely clustered with gamma-Proteobateria. Two members (Malan A-21 and 101) of alpha-Proteobacteria from the sample of 35 m and two (Malan B-26 and 48) of beta-Proteobacteria of 64 m were loosely clustered (< 95% similarity) with known bacteria, represented new genera in ice bacteria.

Bacteria↗
PubMed2001

Isolation and characterization of the major form of human MUC18 cDNA gene and correlation of MUC18 over-expression in prostate cancer cell lines and tissues with malignant progression.

Ectopical expression of huMUC18, a cell adhesion molecule in the immunoglobulin gene superfamily, causes a non-metastatic human melanoma cell line to become metastatic in a nude mouse system. To determine if MUC18 expression correlates with the development and malignant progression of prostate cancer, we investigated differential expression of human MUC18 (huMUC18) in normal prostate epithelial cells, prostate cancer cell lines, and prostatic normal and cancer tissues. We cloned and characterized the human MUC18 (huMUC18) cDNA gene from three human prostate cancer cell lines and three human melanoma cell lines. The cDNA sequences from the six human cancer cell lines were identical except differences in one to five nucleotides. The deduced amino acid sequences of the longest ORF were 646 amino acids that were identical in these cDNAs except for one to three amino acid residues. The amino acid sequences of all our huMUC18 cDNA genes are similar to that cloned by other group (GenBank access #M28882) except differences in the same seven amino acids. We conclude that huMUC18 cDNA gene reported here represents the gene product from a major allele. The MUC18 mRNA and protein was expressed in three metastatic prostate cancer cell lines (TSU-PR1, DU145, and PC-3), but not in one non-metastatic prostate cancer cell line (LNCaP.FGC). The expression of huMUC18 in these four cell lines is positively related to their extent of in vitro motility and invasiveness and in vivo metastasis in nude mice. HuMUC18 protein was also expressed at high levels in extracts prepared from tissue sample sections containing high grade prostatic intraepithelial neoplasia (PIN), but weakly expressed in extracts prepared from cultured primary normal prostatic epithelial cells and the normal prostate gland. Immunohistochemical analysis showed that huMUC18 was expressed at higher levels in the epithelial cells of high-grade PIN and prostatic carcinomas, and in cells of a perineural invasion, a lymph node, and a lung metastases compared to that in normal or benign hyperplastic epithelium (BPH). We therefore conclude that MUC18 expression is increased during prostate cancer initiation (high grade PIN) and progression to carcinoma, and in metastatic cell lines and metastatic carcinoma. Increased expression of MUC18 is implicated to play an important role in developing and malignant progression of human prostate cancer. Furthermore, the lacking of predominant cytoplasmic membrane expression of MUC18 appeared to correlate with malignant progression of prostate cancer.

Amino Acid Sequence↗
PubMed2001

[Influence of human cytomegalovirus infection on the expression of HOXB5, HOXB6, HOXB7, and HOXB8 genes in gliomaous cells].

OBJECTIVE: The expressions of HOXB5, HOXB6, HOXB7, and HOXB8 genes of U251 cell infected by human cytomegalovirus and/or treated with all trans-retinoic acid(ATRA) were detected by semi-quantitative RT-PCR. The results were that U251 cell did not express HOXB5, HOXB6, and HOXB8 but expressed HOXB7 without infecting HCMV and/or being treated with ATRA. After infected with HCMV and/or treated with ATRA, the expressions of HOXB7 and HOXB8 were up-regulated and the expression of HOXB7 lasted the fourth generation, while HOXB8 was up-regulated only in the second generation. These results indicate that the abnormal expression of HOXB gene induced by HCMV may play an important role in the maldevelopment.

Brain Neoplasms↗
PubMed2001

Expression of a human cell adhesion molecule, MUC18, in prostate cancer cell lines and tissues.

BACKGROUND: Over expression of huMUC18, a cell adhesion molecule in the immunoglobulin gene superfamily, causes a non-metastatic human melanoma cell line to become metastatic in a nude mouse system. To determine if MUC18 expression correlates with the malignant progression of prostate cancer, we investigated differential expression of human MUC18 (huMUC18) in normal prostate epithelial cells, prostate cancer cell lines, and prostatic normal and cancer tissues. METHODS: RT-PCR and Western blot analyses were used to analyze the expression of MUC18 mRNA and protein in four human prostate cancer cell lines, cultured primary normal prostate epithelial cells, normal prostate and malignant prostate tissues. Immunohistochemistry was used to determine the expression of MUC18 antigen in prostatic tissues at different stages of malignancy. RESULTS: Human MUC18 mRNA and protein was expressed in three different prostate cancer cell lines (TSU-PR1, DU145, and PC-3), but not in one prostate cancer cell line (LNCaP.FGC). HuMUC18 protein was also expressed at high levels in extracts prepared from tissue sample sections containing high grade prostatic intraepithelial neoplasia (PIN), but weakly expressed in extracts prepared from either cultured primary normal prostatic epithelial cells or the normal prostate gland. Immunohistochemical analysis showed that huMUC18 was expressed at higher levels in the epithelial cells of high-grade PIN and prostatic carcinomas and in cells of a lymph node metastasis compared to that in normal or benign hyperplastic epithelium (BPH). CONCLUSIONS: We therefore conclude that MUC18 is expressed at higher levels in pre-malignant and malignant prostatic epithelium, including metastasis. We suggest that over-expression of MUC18 may be a new marker of human prostate cancer and also implicates its possible role in development and progression of prostate cancer.

Antigens, CD↗
PubMed2001

[Listeria monocytogenes induces thymocyte apoptosis in mice].

The murine thymocyte apoptosis induced by Listeria monocytogenes(LM) was detected with morphology, FCM, and DNA electrophoresis. The results were that LM elicited typical morphological changes of thymocyte apoptosis; the typical apoptosis peak was displayed with FCM, and typical "ladder pattern" with agarose gel electrophoresis. The apoptotic cells were found at 8 h after the mice had infected LM and reached climax at 48 h. The thymus weight significantly reduced at 16 h, and reached the lowest at 48 h after the mice had infected LM. The percentage of apoptotic cells was raised with the increasing of LM. These results suggest that LM induces thymocyte apoptosis in dose- and time-dependent manner.

Animals↗
PubMed2001

[Influence of human cytomegalovirus infection on the expressions of HOXB1, HOXB5, HOXB6, and HOXB9 genes in human embryo lung cells].

OBJECTIVE: To study the expressions of HOXB1, HOXB5, HOXB6, and HOXB9 genes in human embryo lung (HEL) cells and influence of human cytomegalovirus (HCMV) infection on the expressions of these genes. METHOD: The expressions of HOXB1, HOXB5, HOXB6, and HOXB9 genes were detected with semi-quantitative RT-PCR method. RESULTS: 1. HEL cells expressed HOXB5 and HOXB6 genes, but they did not express HOXB1 and HOXB9 genes. 2. After HCMV infection, HEL cell was induced to express HOXB9 gene, as the expression of HOXB6 gene was elevated. The expression of HOXB5 gene had no significant change. HOXB1 was still not expressed. 3. Treated with all-trans retinoic acid (ATRA), the expression of HOXB9 gene in HEL cells infected by HCMV was significantly increased. But during the advanced infect period, the expression of HOXB6 was significantly decreased. CONCLUSION: HCMV can induce abnormal expressions of HOXB6 and HOXB9 genes, which may play an important role in HCMV-induced abnormal embryogenesis.

Cells, Cultured↗
PubMed2001

[Study on molecular epidemiology of HCMV infection in mothers and their newborns in Changsha].

The detection of HCMV-IgG, IgM in plasma by ELISA and DNA in plasma and P(C) BMCs from mothers and their newborns by PCR was carried out. Positive HCMV-IgG, HCMV-IgM, P(C)BMCs HCMV DNA and plasma HCMV DNA were demonstrated in 119(95.2%), 7(5.6%), 27(21.6%) and 14(11.2%) in 125 mothers and 117(93.6%), 1(0.8%), 18(14.4%) and 7(5.6%) in their mewborns, respectively. There were significant differences among the positive rate of newborn's HCMV-IgM, plasma HCMV DNA and CBMCs HCMV DNA (P < 0.05), but the difference between HCMV-IgM and plasma HCMV DNA had no statistic significance (P > 0.05). This study suggests that HCMV-IgG and CBMCs HCMV PCR are preferable epidemiological index of HCMV infection of pregnant women and newborns respectively.

Adult↗
PubMed2001

Effects of propofol on mitochondrial function and intracellular calcium shift in bovine aortic endothelial model.

BACKGROUND: Hypotension was commonly encountered in clinical practice during induction of anesthesia with propofol. The purpose of this study is to investigate the effect of propofol on mitochondrial membrane potential and morphology so as to infer its relation with intracellular calcium mobilization in bovine aortic endothelium. METHODS: In this study, we used the cultured bovine aortic endothelial cells (Gm 7372a) to elucidate the impact of propofol upon the membrane potential and morphology of mitochondria in correlation with its effect on intracellular calcium shift. The intracellular calcium mobilization within the cells preincubated with or without propofol was evaluated using a fluorescent spectrophotometer (confocal microscope) after being treated with Fluo-3. The mobilization of intracellular calcium was demonstrated by the appearance of "hot spots" released from intracellular stores after the addition of an ionophore, ionomycin, to the incubation system. The membrane potential of mitochondria was measured by DiOC6 and the morphology of the mitochondria was evaluated by the treatment of TM Ros and compared with that by the treatment of the uncoupler, FCCP, as control. RESULTS: The release of calcium "hot spots" from the intracellular stores (e.g. mitochondria) after the addition of ionomycin was visualized to decrease dramatically within the endothelial cells after preincubation with propofol. The membrane potential of mitochondria was significantly inhibited by pretreatment of propofol at 0.01 mM, 37 degrees C for 30 min. Morphologically, the integrity of mitochondria was distorted and fragmented in the presence of propofol as compared with that of control. CONCLUSIONS: Our data showed that propofol in clinical concentration, 0.01 mM, could inhibit intracellular calcium shift from the intracellular stores and decrease the membrane potential and distort the morphology of mitochondria in bovine aortic endothelial cells. These inhibitions of the function and disfiguration of the morphology of mitochondria signify that the clinical hypotension induced by propofol might be of a potential mechanism.

Anesthetics, Intravenous↗
PubMed2001

[The analgesic and antispasmodic effects of guang tong xiao aerosol of TCM].

OBJECTIVE: To observe the analgesic and antispasmodic effects of Guang Tong Xiao Aerosol (GTXA). METHOD: Writhing test and tail-flick of physical stimulation were made to study the analgesic effect on mice and rats. RESULT AND CONCLUSION: GTXA given by gastrogavage in dose of 18.75 g.kg-1 or 12.50 g.kg-1 could markedly raise the pain threshold after chemical stimulation in mice and physical stimulation in rats, and had antispasmodic effects.

Aerosols↗
PubMed2000

[Influence of human cytomegalovirus infection on the expression of HOX genes in human embryo lung cells].

The expressions of HOX genes in human embryo lung (HEL) cells were detected with semi-quantitative RT-PCR method. The results were that HEL cells expressed HOXB7 gene and its expression increased after human cytomegalovirus (HCMV) infection. The level of expression reached maximum at 48 h after HCMV infection. Treated with all-trans retinoic acid (ATRA), the expression of HOXB7 in HEL cells infected by HCMV was significantly increased. The results suggest that the abnormal expression of HOX genes induced by HCMV might possibly play a role in virus-induced abnormal embryogenesis.

Cells, Cultured↗
PubMed2000

17q23 amplifications in breast cancer involve the PAT1, RAD51C, PS6K, and SIGma1B genes.

Amplification of the 17q23 region occurs frequently in breast tumors. To characterize the structure of 17q23 amplicons and to identify oncogene targets associated with this alteration, we performed a copy number analysis of 87 17q23 localized expressed sequence tags in seven breast cancer cell lines. Three major regions of amplification were detected in the MCF7 and BT474 cell lines. Amplification of at least one of four known genes (PAT1, PS6K, RAD51C, and SIGMA1B) was detected in the cell lines and in 28% of 94 breast tumors. In most cases, these four genes were overexpressed when amplified, but there was a particularly good association between amplification of the SIGMA1B gene and elevated expression in tumors, which suggested a possible role for this gene in tumor progression. Our data show that this region contains at least four independent targets of amplification, which suggests that there is considerable variability in the structure of the 17q23 amplicon.

Breast Neoplasms↗
PubMed2000

[Investigation of the effects of biotic field of plant seedling on human body].

In this paper we investigated the effects on human bodies after being placed in the Jiang's guideti cabin with biotic field to receive the plant seedlings' irradiating biological electromagnetic waves. The results found that the erythrocyte membrane permeability and fragidity were decreased, its tenacity increased, the secretion of thyroid and sexual hormones increased, the immune function enhanced and there was no significant alteration of the adrenal cortical hormone secretion. It is suggested that the electromagnetic wave from the plant seedlings is beneficial to the erythrocyte function, improves the metabolism, enhances the adolescent activities, improves sexual activity and enhances immune function, thus it is effective to health care and rejuvenation.

Adult↗
PubMed2000

The cytotoxicity of corrosion products of nitinol stent wire on cultured smooth muscle cells.

Although nitinol is one of most popular materials of intravascular stents, there are still few confirmative biocompatibility data available, especially in vascular smooth muscle cells. In this report, the nitinol wires were corroded in Dulbecco's modified Eagle's medium with constant electrochemical breakdown voltage and the supernatant and precipitates of corrosion products were prepared as culture media. The dose and time effects of different concentrations of corrosion products on the growth and morphology of smooth muscle cells were evaluated with [(3)H]-thymidine uptake ratio and cell cycle sorter. Both the supernatant and precipitate of the corrosive products of nitinol wire were toxic to the primary cultured rat aortic smooth muscle cells. The growth inhibition was correlated well with the increased concentrations of the corrosion products. Although small stimulation was found with released nickel concentration of 0.95 +/- 0.23 ppm, the growth inhibition became significant when the nickel concentration was above 9 ppm. The corrosion products also altered cell morphology, induced cell necrosis, and decreased cell numbers. The cell replication was inhibited at the G0-G1 to S transition phase. This was the first study to demonstrate the cytotoxicity of corrosion products of current nitinol stent wire on smooth muscle cells, which might affect the postimplantation neointimal hyperplasia and the patency rate of cardiovascular stents.

Alloys↗
PubMed2000

Effects of four methods of sperm preparation on motion characteristics and nitric oxide concentration in laboratory-prepared oligospermia.

BACKGROUND: To compare four different spermatozoa preparation methods in semen samples with respect to recovery rate, percent motility, path and progressive velocity, and nitric oxide (NO) production before and after centrifugation. METHODS: Each of 36 semen specimens was diluted to 1 x 10(6)/ml and divided into four 1-ml aliquots for sperm processing using four methods: swim-up, two (Percoll II) and three (Percoll III) layer Percoll (Pharmacia Biotech AB, Uppsala, Sweden) gradients and albumin columns. The motile sperm recovery rate, percent motility and motion parameters were measured for each semen specimen (n = 36) before and after processing using the four methods. NO was measured with the use of a chemiluminescence method before and after centrifugation (n = 17). RESULTS: The sperm recovery rate was higher using both Percoll gradients than with the other two methods (Percoll II, 68 +/- 20.5%, Percoll III, 75.3 +/- 22.2% vs swim-up, 25.8 +/- 9.9% and albumin, 33.1 +/- 20.7%). The results were similar for total motile cells (Percoll II, 3.55 +/- 1.72 x 10(6)/ml, Percoll III, 4.25 +/- 1.29 x 10(6)/ml vs swim-up, 1.19 +/- 0.71 x 10(6)/ml and albumin, 1.89 +/- 1.36 x 10(6)/ml). Both Percoll methods and the albumin method produced a statistically significant improvement over the swim-up method in motility. The albumin column method resulted in the least path and progressive velocities (51.3 +/- 15.4 microns/s and 46.2 +/- 16.5 microns/s, respectively). NO produced during sperm processing did not differ significantly among the four processing methods (swim-up, 4,531 +/- 1,626 nM, Percoll II, 5,119 +/- 3,969 nM, Percoll III, 6,060 +/- 5,512 nM, albumin 4,838 +/- 2,462 nM). CONCLUSIONS: Our data suggest that Percoll methods are superior to swim-up and albumin columns for sperm preparation, yielding good sperm recovery, motility and motion characteristics. The trend toward lower NO levels among samples prepared using albumin columns did not reach statistical significance.

Cell Separation↗
PubMed2000

Study of propofol in bovine aortic endothelium: I. Inhibitory effect on bradykinin-induced intracellular calcium immobilization.

BACKGROUND: Propofol has been found to affect the intracellular calcium concentration with clinical manifestations of hypotension and bradycardia. The purpose of this study is to examine the effect of propofol on intracellular calcium immobilization in bovine aortic endothelium under the stimulation of bradykinin. METHODS: In order to validate the effect of propofol on the alteration of intracellular calcium concentration, we used the cultured bovine endothelial cells (Gm 7372a) to measure the calcium immobilization within the cells preincubated with or without propofol of clinical concentration. Using Fluo-3 staining and a fluorescence spectrophotometer (confocal microscope), intracellular calcium immobilization was demonstrated by the appearance of "hot spots" within the cytoplasm and perinuclear regions after addition of bradykinin to the cells. The changes of fluorescence density measured within these areas versus the effect of time were analyzed and compared with the cells in control group. RESULTS: After addition of bradykinin, intracellular calcium hot spots increased dramatically within seconds and reached a maximal level within 20 seconds. The concentrations of calcium gradually decreased to a constant level after about 3 min following the addition of bradykinin to the cells. With pretreatment of propofol at 0.01 mM and 37 degrees C for 30 min, the immobilization of intracellular calcium from the intracellular stores were significantly inhibited that was demonstrated by the decreased appearance of hot spots when compared with control. CONCLUSIONS: Our data demonstrated that under the stimulation of bradykinin, propofol at 0.01 mM, could inhibit intracellular calcium release from the intracellular stores in bovine aortic endothelial cells. This phenomenon might explain the possible mechanism for the clinical manifestations of hypotension and/or bradycardia associated with propofol.

Anesthetics, Intravenous↗
PubMed1999

The cardiomyopathy and lens cataract mutation in alphaB-crystallin alters its protein structure, chaperone activity, and interaction with intermediate filaments in vitro.

Desmin-related myopathy and cataract are both caused by the R120G mutation in alphaB-crystallin. Desmin-related myopathy is one of several diseases characterized by the coaggregation of intermediate filaments with alphaB-crystallin, and it identifies intermediate filaments as important physiological substrates for alphaB-crystallin. Using recombinant human alphaB-crystallin, the effects of the disease-causing mutation R120G upon the structure and the chaperone activities of alphaB-crystallin are reported. The secondary, tertiary, and quaternary structural features of alphaB-crystallin are all altered by the mutation as deduced by near- and far-UV circular dichroism spectroscopy, size exclusion chromatography, and chymotryptic digestion assays. The R120G alphaB-crystallin is also less stable than wild type alphaB-crystallin to heat-induced denaturation. These structural changes coincide with a significant reduction in the in vitro chaperone activity of the mutant alphaB-crystallin protein, as assessed by temperature-induced protein aggregation assays. The mutation also significantly altered the interaction of alphaB-crystallin with intermediate filaments. It abolished the ability of alphaB-crystallin to prevent those filament-filament interactions required to induce gel formation while increasing alphaB-crystallin binding to assembled intermediate filaments. These activities are closely correlated to the observed disease pathologies characterized by filament aggregation accompanied by alphaB-crystallin binding. These studies provide important insight into the mechanism of alphaB-crystallin-induced aggregation of intermediate filaments that causes disease.

Cardiomyopathies↗
PubMed1999

Site-directed mutations within the core "alpha-crystallin" domain of the small heat-shock protein, human alphaB-crystallin, decrease molecular chaperone functions.

Site-directed mutagenesis was used to evaluate the effects on structure and function of selected substitutions within and N-terminal to the core "alpha-crystallin" domain of the small heat-shock protein (sHsp) and molecular chaperone, human alphaB-crystallin. Five alphaB-crystallin mutants containing single amino acid substitutions within the core alpha-crystallin domain displayed a modest decrease in chaperone activity in aggregation assays in vitro and in protecting cell viability of E. coli at 50 degrees C in vivo. In contrast, seven alphaB-crystallin mutants containing substitutions N-terminal to the core alpha-crystallin domain generally resembled wild-type alphaB-crystallin in chaperone activity in vitro and in vivo. Size-exclusion chromatography, ultraviolet circular dichroism spectroscopy and limited proteolysis were used to evaluate potential structural changes in the 12 alphaB-crystallin mutants. The secondary, tertiary and quaternary structures of mutants within and N-terminal to the core alpha-crystallin domain were similar to wild-type alphaB-crystallin. SDS-PAGE patterns of chymotryptic digestion were also similar in the mutant and wild-type proteins, indicating that the mutations did not introduce structural modifications that altered the exposure of proteolytic cleavage sites in alphaB-crystallin. On the basis of the similarities between the sequences of human alphaB-crystallin and the sHsp Mj HSP16.5, the only sHsp for which there exists high resolution structural information, a three-dimensional model for alphaB-crystallin was constructed. The mutations at sites within the core alpha-crystallin domain of alphaB-crystallin identify regions that may be important for the molecular chaperone functions of sHsps.

Amino Acid Sequence↗