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Biomedical subjects

W Zhou

Publications and source records attributed to W Zhou.

At least 145 records · Page 8Linked to original sources
PubMed2000

[A clinical comparative study of interferon alpha-2b with mitomycin C applied in glaucoma filtering operation].

OBJECTIVE: To compare the results of interferon alpha-2b (IFN alpha-2b) with mitomycin C (MMC) treatment in trabeculectomy. METHOD: 41 cases 68 eyes with late stage of primary open angle glaucoma (POAG) were randomly studied by treatment with IFN alpha-2b or MMC following trabeculectomy, each group consisting of 34 eyes. Of the cases, 27 were bilateral, one eye was designed to use IFN alpha-2b, and the other eye, apply MMC. All patients were ranged from 15 to 40 years old, and they all received the surgery the first time. The surgical procedure was similar in all eyes. The IFN alpha-2b treated eyes were subconjunctivally injected 5 x 10(5) IU at filtering bleb when the operation was finished immediately and on the postoperative day 3, 7, 10 and 14, respectively. The MMC-receiving eyes were intraoperatively administered with 0.25 mg/ml via a sponge under the conjunctival flap for 5 minutes. The follow-up was ranged from 6 to 15 months. RESULTS: (1) The 12th month life-table success rate of functional bleb formation was (70.95 +/- 9.72)% in IFN alpha-2b-treated group and (77.01 +/- 10.51)% in MMC-received group, the difference being not statistically significant (u = 0.2165, P > 0.05). The eyes with IFN alpha-2b tended to form type II blebs were according to Kronfeld classification, whereas type I blebs were commonly seen in MMC-treated eyes (chi(2) = 6.261, P < 0.05). The percentages of intraocular pressure between 10 - 15 mmHg on postoperative month 3, 6, 9 and 12, respectively in IFN alpha-2b group were higher than that in MMC group. (2) The 12th month life-table complete and qualified success rates were (70.95 +/- 9.72)% and (94.59 +/- 5.26)% in IFN alpha-2b group, (65.15 +/- 10.51)% and (84.61 +/- 7.26)% in MMC group, respectively (u = 0.8174, 0.1011, P > 0.05). (3) Complications induced by IFN alpha-2b were rare, mainly involving transient corneal epithelial defect, whereas by MMC included thin-wall blebs, persistent hypotony and hypotonous maculopathy. The decrease of visual acuity was seen in 44.1% of the cases in MMC group, whereas only 17.6% occurred in IFN alpha-2b group (chi(2) = 5.217 4, P < 0.05). CONCLUSION: IFN alpha-2b has similar effect as MMC to reduce the risk of failure of glaucoma filtration surgery, but it has more advantages over because of its fewer complications.

Adolescent↗
PubMed2000

[Optical coherence tomography applied for measurement of nerve fiber layer thickness in normal eyes].

OBJECTIVE: To evaluate the efficiency of optical coherence tomography (OCT) on quantifying retinal nerve fiber layer (RNFL) thickness and its reproducibility and investigate the difference of RNFL thickness between different groups. METHODS: According to their age, 152 eyes of 152 normal subjects were classified into six groups (such as 10 year, 20 year group, etc.), and investigated by OCT to measure the RNFL thickness. Each subject had circular scans around the optic nerve with a circle size of 3.46 mm. The RNFL thickness in different groups was analyzed. Intraclass correlation coefficient (ICC) in fifty eyes of 37 subjects was calculated. RESULTS: The mean RNFL thickness of 152 eyes was (90.09 +/- 10.81) microm, (140.27 +/- 10.60) microm, (85.03 +/- 14.01) microm, (140.27 +/- 9.70) microm and (114.11 +/- 6.08) microm (temporal, superior, nasal, inferior and the mean of the whole layer, respectively). Least significant difference (LSD)-t test was applied for multiple thickness comparisons of the mean and different quadrants among different groups. The results showed there were significant differences between the 60 year group and others except the 50 year group in temporal, superior, inferior quadrants and mean RNFL thickness (P = 0.000 - 0.019), and between each of 10 to 40 year groups and each of 50 to 60 year groups in the mean RFNL thickness (P = 0.000 - 0.026). ICCs of RNFL thickness measured by OCT were 0.78, 0.66, 0.64, 0.52 and 0.74 (temporal, superior, nasal, inferior and mean, respectively). CONCLUSIONS: Normal RNFL thickness can be measured accurately by OCT. There are some differences of RNFL thickness between different groups in normal persons.

Adolescent↗
PubMed2000

[Qualitative and quantitative measurement of retinal nerve fiber layer in primary open angle glaucoma by optical coherence tomography].

OBJECTIVE: To study the characteristics of optical coherence tomography (OCT) of primary open angle glaucoma (POAG), the difference of retinal nerve fiber layer (RNFL) thickness between normal persons and patients with POAG and the correlation between RNLF and visual field index. METHODS: Eighty-three cases (149 eyes) with POAG and 83 normal persons (150 eyes) were tested by OCT with circular scans around the optic nerve head (diameter = 3.46 mm) to observe the features of OCT. Statistic analysis was taken to compare the difference of RNFL thickness in quadrants and means between normal and glaucomatous group, and the difference of the thickness among the stages in POAG. Linear correlation and regression analysis was used to show the correlation between RNFL thickness and visual field index of 115 eyes of glaucomatous patients. RESULTS: The RNFL thickness measured by OCT in normal subjects is the thickest in superior and inferior quadrants, less in thickness in temporal and the thinnest in nasal quadrant. The curve showed double peaks. The RNFL of glaucomatous patients showed local thinness or defect, diffuse thinness or combination of the above two types. The mean RNFL thickness of normal group was (90.1 +/- 10.8) microm, (140.4 +/- 10.5) microm, (85.2 +/- 14.0) microm, (140.4 +/- 9.7) microm and (114.2 +/- 6.0) microm, of glaucomatous group was (56.0 +/- 31.0) microm, (81.0 +/- 36.3) microm, (47.1 +/- 27.5) microm, (73.4 +/- 38.4) microm and (64.6 +/- 28.8) microm in temporal, superior, nasal, inferior quadrant and the whole area, respectively. There is significant difference of RNFL thickness between the normal and glaucomatous group (P < 0.000), and there are significant differences among the three stages (early, developing and late) of glaucomatous group (P < 0.000). There is a close negative relationship between RNFL thickness and visual field index (r = -0.796, P < 0.0001). The sensitivity and specificity of RNFL thickness measured by OCT were 93.3% and 92.0%, respectively. CONCLUSION: OCT can quantitatively measure the RNFL thickness and show the difference of RNFL between normal persons and glaucomatous patients. The RNFL thickness gradually decreases while visual field defect increases with the development of POAG.

Adolescent↗
PubMed2000

[A case-control study on the risk factors of epidemic hemorrhagic fever].

OBJECTIVE: To study the risk factors of epidemic hemorrhagic fever (EHF). METHODS: A 1:1 matched case-control study was conducted to analyse EHF risk factors. RESULTS: One hundred and eighty-five matched pairs were investigated. Five factors were associated with risks of the disease, including rodent activity in house, farm working, travel, annual average income of an individual and ground material of the house, when chi(2) test and logistic regression model were processed respectively. The coefficients of rodent activity in house, farm working, travel, annual average income of an individual and ground material of the house in multivariable Logistic regression model were 1.377, 1.687, 1.630, -1.216 and -0.888, respectively, when P value < 0.05 was observed. CONCLUSIONS: Factors as high average income of individuals, brick or cement used as material of the ground in the house, seemed to be protective factors of EHF, which were important to the control and prevention of EHF.

Adult↗
PubMed2000

[Safety and immunogenicity of inactivated bivalent EHF vaccine in humans].

OBJECTIVE: Safety and immunogenicity of inactivated bivalent EHF vaccine in humans were evaluated in the epidemic area of Zhejiang province, China. METHODS: Susceptible persons with negative anti-EHF were selected in Jiande county, Zhejiang province to receive 3 doses of inactivated bivalent EHF vaccine at 0, 7, 28 days. A booster injection was given one year after the primary immunization. Antibody responses were measured in human volunteers by IFA and MCPENT. Local and general reactions were recorded within 72 hours after each vaccination by physicians. RESULTS: Two weeks after the primary vaccination, 99.04% of the subjects developed significant hantavirus antibody titre measured by IFA which had a 37.34% drop one year after the primary vaccination. Seroconversion rate increased to 100% two weeks after the booster dose. Neutralising antibody titres paralleled this trend with 100% of vaccine recipients producing neutralising antibody two weeks after the primary doses. However, it dropped to 80% one year after the primary vaccination. One hundred percent of the vaccine recipients started to respond two weeks after boosting. The geometric mean titre (GMT) of neutralising antibody against 76 - 118 and UR were 18.27 +/- 2.21 and 12.47 +/- 2.16 respectively after the primary injections, but it increased to 37.09 +/- 2.24 and 32.61 +/- 2.05 respectively after the secondary immunization. General and local reaction rates were 0.46% and 1.98%, with no severe side effects observed in the vaccinees. CONCLUSION: The vaccine was well tolerated and could induce good humoral immune response.

Antibodies, Viral↗
PubMed2000

[Effects of methyl tertiary butyl ether on cell cycle and cell apoptosis].

OBJECTIVE: To explore the effects of the new gasoline additive, methyl tertiary butyl ether (MTBE) on cell cycle and cell apoptosis. METHODS: Flow cytometry was used to evaluate the effect of MTBE (1, 2, 4 microl/ml, 24 h) on NIH/3T3 cell cycles; and the effect of MTBE on Hela cell apoptosis was evaluated by detecting cell survival using crystal violet staining. RESULTS: Flow cytometry showed that MTBE could change NIH/3T3 cell cycles, decrease the number of cells in S stage, and arrest cells at G(2) + M stage. The results suggested that MTBE could affect NIH/3T3 cell cycles and induce cell proliferation. This situation existed 48 hours after the treatment, and cell cycles came back normal 96 hours after the treatment. By detecting cell survival using crystal violet staining, we found that MTBE could inhibit the apoptosis of Hela cells which was induced by tumor necrosis factor (TNF)alpha and cycloheximide. CONCLUSION: MTBE's carcinogenicity to animals may relate to induction of cell proliferation and inhibition of cell apoptosis.

3T3 Cells↗
PubMed2000

[Effects of bite force lost on the expression of IL-6 in the rat periodontium].

OBJECTIVE: In order to explain the molecular mechanism of periodontium remodeling the expression of IL-6 in the rat periodontal ligament fibroblasts (PDLC) and the alveolar bone osteoblasts under normal and bite force lost was studied. METHODS: To establish a rat model of different bite force for the study, left maxillary molars of rats were extracted and the left mandibular molar area was used as the bite force lost. The animals were sacrificed after 6 hours, 1, 2, 3 days and 1, 2, 3, 4 weeks. The prepared tissue specimens were processed for the study of the change in the histologic morphology and the expression of IL-6 protein in PDLC and osteoblasts with HE staining and immunohistochemistry techniques. RESULTS: In the group of bite force lost, the loosely arrangement of periodontal ligaments and the resorption of alveolar bone were observed in histological study, the expression of IL-6 in PDLC and osteoblasts was enhanced apparently than that in the group of normal bite force by using immunohistochemistry techniques. In the group of lost bite force, the expression of IL-6 in PDLC enhanced with time regularly: The expression of IL-6 was strengthened after 3 days, and reached the peak after 2 weeks, then, decreased after that and restored to normality in 4 weeks. While in osteoblasts of the group of bite force lost, the expression of IL-6 was strengthened just after 2 weeks. CONCLUSION: Bite force lost induce the expression of IL-6 enhanced apparently in PDLC and osteoblasts, it suggests that IL-6 may play important roles in the effect of bite force on periodontium remodeling. It approaches initially the molecular mechanism of periodontium remodeling, demonstrates that the histologic morphology is closely related to the mechanical condition.

Alveolar Bone Loss↗
PubMed2000

[Electrophoresis identification of four kinds of seed-fruit Chinese drugs and its adulterants].

OBJECTIVE: To identify four kinds of seed-fruit Chinese drugs and its adulterants by electrophoresis and to research the dyeing effect of Coomassie Brilliant Blue G-250. METHOD: Gel electrophoresis of soluble protein. RESULTS: The electrophoretograms of the four kinds of Chinese drugs and its adulterants are remarkably different. CONCLUSION: The electrophoretograms can be used to differentiate the four kinds of Chinese drugs and its adulterants. Coomassie Brilliant Blue G-250 can be used in the electrophoresis identification.

Canavalia↗
PubMed2000

[Survival motor neuron gene and neuronal apoptosis inhibitory protein gene deletion in patients with spinal muscular atrophy].

OBJECTIVE: To investigate the frequencies of gene deletion survival motor neuron telomere (SMNTel) exon 7 and neuronal apoptosis inhibitory protein gene (NAIP) exon 5 in 55 Chinese spinal muscular atrophy (SMA) patients, and compare the relationship between these two candidate genes and the disease. METHODS: PCR-SSCP method was used to detect the deletion of SMNTel exon 7, direct visualization of PCR products by agarose electrophoresis was used to detect the deletion of NAIP exon 5 in 55 SMA patients with type I and type II. 40 normal individuals were involved in the study as controls. RESULTS: Homozygous deletion of the SMNTel exon 7 was identified in 92% (23/25) of SMA type I patients and 90% (27/30) of SMA type II patients. The same deletion was found in two mothers and one father of SMA patients. There was no homozygous deletion found in normal controls. None of the homozygous deletion of NAIP exon 5 was found in 55 SMA patients and normal controls. Only two patients were found to have the heterozygous deletion. CONCLUSIONS: The frequency of homozygous deletion of SMNTel exon 7 was 90.1%. Our data support that SMN gene is strongly associated with SMA.

Adult↗
PubMed2000

[Studies on the infrared spectra of clusters containing O3MoS3, [Mo(x) (CO)y(O,S-C6H4-1,2)3FezLm]n- (x = 1,2 or 3, y = 0,3,7 or 4, z = 0 or 1, L = Cl, m = 0,2, n = 1 or 2) unit and the relationship between the spectra and their structures].

The IR spectra of clusters containing O3MoS3 Unit, (Et4N) [Mo(O, S-C6H4-1,2)3](1), (Et4N)2[Mo2(CO)3(O,S-C6H4-1,2)3](2), (Et4N)2[Mo3(CO)7(O,S-C6H4-1,2)3](3) and (Et4N)2[Mo2(CO)4(O,S-C6H4-1,2)3FeCl2](4) have been investigated. The characteristic frequencies, nu (Mo(n+)-OtR) (n = 4,5), nu (Mo(n+)-ObR) (n = 0,4), nu (Mo(n+)-StR) (n = 4,5), nu (Mo(n+)-SbR)(n = 0,1,4), nu (C = O), nu (Mo(n+)-C)(n = 0,1), delta (Mo(n+)-C-O)(n = 0,1), nu (Fe(2+)-ObR) and nu (Fe(2+)-Cl) were assigned by comparing the vibrational frequencies and structure parameters of them with that of Mo-Fe-S clusters. The influences of sigma donor abilities of ligands L(-OR, -SR) on nu (Mo-C) and nu (C = O) and the effect of Mo(n+)-->Mo4+ (n = 0,1) charge transfer on nu (Mo(4+)-ObR), nu (Mo(n+)-C) and nu (C = O) have been discussed. A partial oxidation of cluster 4 to [Mo2(CO)3(O,S-C6H4-1,2)3]- (5) have been inferred according to the information from the changes of IR spectra of cluster 4 in air with time and the existence of cluster 5 was also verified by NFAB-MS of cluster 4.

English Abstract↗
PubMed2000

[The electrophilic and electrophobic effect in molecular vibration spectra].

A new point of view for electronic effect of molecular vibration spectra was brought: the electrophilic effect of substitution group can enhance the strength of covalent bond. Therefore, its stretching vibration frequency will be increased. Contrarily, electrophobic effect makes frequency decrease. As far as the coordination bond is concerned, if electrophobic substitution group links up the atom which provides the electron doublet then the strength of coordination bond will be enhanced and the stretching vibration frequency of the bond will be increased. The electrophilic substitution group makes the frequency decrease. If substitution group links with the atom that accepts electron, the electronic effect of substitution group is on the contrary.

English Abstract↗
PubMed1999

Molecular cloning and mapping of a novel ADAM gene (ADAM29) to human chromosome 4.

Members of the ADAM family (type I integral membrane protein with a disintegrin and metalloprotease domain) have been implicated in many important biological processes involving cell-cell and cell-matrix interactions, such as fertilization and myoblast fusion. We report here the cDNA sequence of a novel human ADAM gene (ADAM29) that contains a putative fusion peptide. Northern blot analysis revealed that the mRNA of ADAM29 is highly expressed in the testis. By radiation hybrid panel mapping, the ADAM29 gene was assigned to human chromosome 4q34.2-qter.

ADAM Proteins↗
PubMed1999

Sequencing and preliminary characterization of the Na+-translocating NADH:ubiquinone oxidoreductase from Vibrio harveyi.

The Na(+)-translocating NADH: ubiquinone oxidoreductase (Na(+)-NQR) generates an electrochemical Na(+) potential driven by aerobic respiration. Previous studies on the enzyme from Vibrio alginolyticus have shown that the Na(+)-NQR has six subunits, and it is known to contain FAD and an FeS center as redox cofactors. In the current work, the enzyme from the marine bacterium Vibrio harveyi has been purified and characterized. In addition to FAD, a second flavin, tentatively identified as FMN, was discovered to be covalently attached to the NqrC subunit. The purified V. harveyi Na(+)-NQR was reconstituted into proteoliposomes. The generation of a transmembrane electric potential by the enzyme upon NADH:Q(1) oxidoreduction was strictly dependent on Na(+), resistant to the protonophore CCCP, and sensitive to the sodium ionophore ETH-157, showing that the enzyme operates as a primary electrogenic sodium pump. Interior alkalinization of the inside-out proteoliposomes due to the operation of the Na(+)-NQR was accelerated by CCCP, inhibited by valinomycin, and completely arrested by ETH-157. Hence, the protons required for ubiquinol formation must be taken up from the outside of the liposomes, which corresponds to the bacterial cytoplasm. The Na(+)-NQR operon from this bacterium was sequenced, and the sequence shows strong homology to the previously reported Na(+)-NQR operons from V. alginolyticus and Haemophilus influenzae. Homology studies show that a number of other bacteria, including a number of pathogenic species, also have an Na(+)-NQR operon.

Amino Acid Sequence↗
PubMed1999

Direct analysis of the products of sequential cleavages of peptides and proteins affinity-bound to immobilized metal ion beads by matrix-assisted laser desorption/ionization mass spectrometry.

Consecutive enzymatic reactions on analytes affinity-bound to immobilized metal ion beads with subsequent direct analysis of the products by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry have been used for detecting protein synthesis errors occuring at the N-terminus. The usefulness of this method was demonstrated by analyzing two commercially available recombinant HIV proteins with affinity tags at the N-terminus, and histatin-5, a peptide with multiple histidine residues. The high specificity, sensitivity, and speed of analysis make this method especially useful in obtaining N-terminal sequencing information of histidine-tagged recombinant proteins.

Amino Acid Sequence↗
PubMed1999

The functional microdomain in transmembrane helices 2 and 7 regulates expression, activation, and coupling pathways of the gonadotropin-releasing hormone receptor.

Structural microdomains of G protein-coupled receptors (GPCRs) consist of spatially related side chains that mediate discrete functions. The conserved helix 2/helix 7 microdomain was identified because the gonadotropin-releasing hormone (GnRH) receptor appears to have interchanged the Asp(2.50) and Asn(7.49) residues which are conserved in transmembrane helices 2 and 7 of rhodopsin-like GPCRs. We now demonstrate that different side chains of this microdomain contribute specifically to receptor expression, heterotrimeric G protein-, and small G protein-mediated signaling. An Asn residue is required in position 2.50(87) for expression of the GnRH receptor at the cell surface, most likely through an interaction with the conserved Asn(1.50(53)) residue, which we also find is required for receptor expression. Most GPCRs require an Asp side chain at either the helix 2 or helix 7 locus of the microdomain for coupling to heterotrimeric G proteins, but the GnRH receptor has transferred the requirement for an acidic residue from helix 2 to 7. However, the presence of Asp at the helix 7 locus precludes small G protein-dependent coupling to phospholipase D. These results implicate specific components of the helix 2/helix 7 microdomain in receptor expression and in determining the ability of the receptor to adopt distinct activated conformations that are optimal for interaction with heterotrimeric and small G proteins.

Animals↗
PubMed1999

Telomere shortening and apoptosis in telomerase-inhibited human tumor cells.

Despite a strong correlation between telomerase activity and malignancy, the outcome of telomerase inhibition in human tumor cells has not been examined. Here, we have addressed the role of telomerase activity in the proliferation of human tumor and immortal cells by inhibiting TERT function. Inducible dominant-negative mutants of hTERT dramatically reduced the level of endogenous telomerase activity in tumor cell lines. Clones with short telomeres continued to divide, then exhibited an increase in abnormal mitoses followed by massive apoptosis leading to the loss of the entire population. This cell death was telomere-length dependent, as cells with long telomeres were viable but exhibited telomere shortening at a rate similar to that of mortal cells. It appears that telomerase inhibition in cells with short telomeres lead to chromosomal damage, which in turn trigger apoptotic cell death. These results provide the first direct evidence that telomerase is required for the maintenance of human tumor and immortal cell viability, and suggest that tumors with short telomeres may be effectively and rapidly killed following telomerase inhibition.

Apoptosis↗
PubMed1999

[Effect of methyl tertiary butyl ether on the expression of proto-oncogenes and function genes].

Methyl tertiary butyl ether (MTBE) is a new gasoline additive, which is used to increase the combustion of gasoline and to reduce the emission of harmful exhaust from automobile. The mechanism for the carcinogenesis of MTBE in animals is not clear. Immunohistochemistry method was used to detect the effect of MTBE on the expression of c-myc and p21 proteins in NIH3T3 cells. Dot hybridization method was used to explore the expression of c-myc gene and GST-P(glutathione S-transferase-P) gene in the of MTBE treated rats. The results showed that MTBE could enhance the expression of c-myc protein, but had no effect on p21 protein. MTBE could induce high expression of c-myc gene, and had no effect on the expression of GST-P gene. These results suggest that the high expression of c-myc gene induced by MTBE might be one of the mechanisms of its carcinogenicity in animal.

3T3 Cells↗