[Detection of hepatitis B virus covalently closed circular DNA in peripheral blood mononuclear cells from patients with chronic hepatitis B infection].
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Biomedical subjects
Publications and source records attributed to Yan Wang.
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OBJECTIVE: To study the relationship between KatG 315 mutation and isoniazid (INH) resistance in M. tuberculosis by template-directed dye-terminator incorporation with fluorescence polarization detection (TDI-FP), and to develop a new method that can detect INH-resistant M. tuberculosis precisely and quickly. METHODS: Isolates of M. tuberculosis resistant to INH from 82 tuberculosis patients were cultured on culture medium with different INH concentrations. DNA of all M. tuberculosis samples was extracted and amplification of 271 bp KatG gene fragment was carried out by polymerase chain reaction (PCR). After digestion of the excess primers and dNTPs in PCR products by clean-up reagents, template-directed dye-terminator incorporation reaction was performed, and the Acyclo-terminators labeled Rhodamine 110 (R110) or 6-carboxytetramethylrhodamine (TAMRA) were incorporated into the detection primers specifically. Then fluorescence polarization value was measured using Victor2 multi-label counter and the genotypes of the mutation site in 315 condon of KatG gene of all samples were investigated. RESULTS: There were 15 out of the 29 isolates of M. tuberculosis with high INH-resistance showed G-->C mutation in 315 condon of KatG gene, including 4 isolates with both mutated and non-mutated trains, the mutation frequency being 52%. In 32 isolates of M. tuberculosis with low INH-resistance, 15 were mixed infection, the mutation frequency being 47%. No mutation in 315 condon of KatG gene was found in 21 susceptible isolates of M. tuberculosis. CONCLUSIONS: The G-->C mutation in 315 condon of KatG gene was associated with INH-resistance of M. tuberculosis. TDI-FP technology was a reliable, easy to use and high-through method to detect mutation of KatG gene. It may be a useful technique for the diagnosis of INH-resistance in the future.
Total mercury concentration of typical wetland plant was analyzed. There were great difference in mercury content among different plants, and the order was moss > alga > carex > herb > shrub. There was a trend of increasing total Hg concentrations from vascular plants to bryophytes, and from dry to wet site. The wetland soil was the source of mercury in the air close to the ground, so it influenced the content of mercury in the plant. In different components of plants, mercury contents were in the order of dead stand > root > leaf > stem. Mercury concentration increased in initial stage and decreased in the end of the growing season. According to the mercury content and biomass, the mercury stock of plant were calculated, and it was 24.9 micrograms.m-2 in the above ground of plant in Calamagrostis angustifolia wetland and 35.8 micrograms.m-2 in Carex lasiocarpa wetland.
OBJECTIVE: To explore the role of endothelin-1 (ET-1) in the pathogenesis of hypertension in obstructive sleep apnea hypopnea syndrome (OSAHS). METHODS: The levels of serum ET-1 in 30 OSAHS patients accompanied by hypertension, 30 normotensive OSAHS patients and 30 healthy controls were measured by ET-1 enzyme immunoassay kit. Meanwhile the correlation about the concentration of ET-1 in OSAHS patients with the clinic, polysomnography (PSG) parameters was analyzed. RESULTS: OSAHS patients with or without hypertension compared with snoring group and normal people, the sleep structure was significantly disturbed. The time percentages of awake and stage I sleep were increased, while stage II sleep decreased significantly in OSAHS patients than those in snoring group (P < 0.01, respectively). There were no significantly difference about the sleep structure in the two OSAHS groups. The levels of serum ET-1 (mean +/- s) were significantly higher in OSAHS patients accompanied by hypertension and normotensive OSAHS patients(42.5 +/- 8.4) ng/L and (38.6 +/- 4.7) ng/L respectively than those in the healthy controls(33.1 +/- 5.4) ng/L (P < 0.01, respectively). In the two OSAHS groups, the levels of serum ET-1 were significantly higher in OSAHS patients accompanied by hypertension than those in the normotensive OSAHS patients (P < 0.05). There were positive correlations between the concentration of ET-1 and the apnea hypopnea index (AHI) in all the 60 OSAHS patients with and without hypertension (r = 0.334, P < 0.01). There were negative correlations between the concentration of ET-1 and the lowest oxygen desaturation in all the 60 OSAHS patients with and without hypertension (r = -0.230, P < 0.05). CONCLUSION: These results indicate that the sleep disordered breathing and hypoxia may contribute to the elevation of ET-1 in the OSAHS patients and OSAHS patients accompanied by hypertension. ET-1 may play an important role in the pathogenesis of OSAHS-induced hypertension.
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OBJECTIVE: To investigate the effects of medroxyprogesterone acetate (MPA) on angiogenesis and growth of transplanted human ovarian cancer cells in nude mice. METHODS: Ovarian cancer cell line COCI derived from human ovarian serous adenocarcinoma was transplanted into 30 nude mice, which were then randomized equally into 3 groups consisting of two treatment groups (in which MPA was administered at 60 and 120 mg/kg, respectively, twice a week for 4 weeks) and a control group. Six weeks later, the body mass of the nude mice was recorded and the morphology of tumor cells observed by electron microscope. The microvascular density (MVD) was examined by immunohistochemical staining with anti-human factor VIII antibody. RESULTS: Compared with the control group, the growth inhibitory rate in the two treatment groups were 23.76% and 43.80%, respectively, corresponding to the doses of 60 and 120 mg/kg. MVD of 60 mg/kg MPA group (3.64+/-0.02) and 120 mg/kg MPA group (2.11+/-0.12) was lower than that of the control group (5.14+/-0.74) (P<0.05 and P<0.01, respectively), and there was also significant difference between the two treatment groups (P<0.01). The morphological changes including compaction and margination of the nuclear chromatin, apoptotic bodies, and cell necrosis were significantly increased in the two treatment groups. CONCLUSIONS: MPA can inhibit the angiogenesis and growth of transplanted human ovarian cancer cells in nude mice in a dose-dependent manner, and its anticancer effect may involve induction of cell apoptosis as the result of its effect against angiogenesis.
OBJECTIVE: The anterior cervical autograft or allograft interbody fusion had become an accepted fusion technique for treating patients with degenerative disorders of the cervical spine. In this retrospective review, a comparison of allograft and autograft of bone was presented. METHODS: A retrospective review of 103 patients who had undergone allograft fusion and 145 patients with autograft fusion between 1997 and 2003, was conducted. Demographics, early complications and length of stay of patient were compared. RESULTS: Longer time on operation with the use of autograft (P < 0.001) and significant increase in length of stay were observed after autograft (P < 0.001). Complication of infections in autograft group was higher than allograft (P < 0.05). CONCLUSIONS: Both autograft and allograft were effective during fusion procedures. Allograft did not appear to be a high risk factor and could decrease medical cost thus could be used clinically for anterior cervical fusion.
OBJECTIVE: To evaluate the prognostic value of expression of fatty acid synthase (FASE), HER-2/neu, bcl-2 and p53 in stage I non-small cell lung cancer (NSCLC). METHODS: Expression of FASE, HER-2/neu, bcl-2 and p53 protein was detected by immunohistochemical staining in 84 patients with stage I NSCLC who underwent surgery. Multiple clinical parameters and survival were analyzed. RESULTS: The expression of FASE, HER-2/neu, bcl-2 and p53 was 29.8%, 40.5%, 33.3% and 39.3%, respectively. The local recurrence and bone-metastasis rate were higher in FASE positive patients than in negative patients (28.0% vs 10.2%, P = 0.05; 61.5% vs 23.9%, P = 0.017, respectively). The 5-year survival rate was lower in HER-2/neu and FASE positive patients than in negative patients (37.7% vs 67.7%, P = 0.0083; 35.1% vs 66.1%, P = 0.0079, respectively), which showed that HER-2/neu and FASE expression were associated with significantly poor survival. Patients whose tumors were both HER-2/neu and FASE negative had better outcome, with a 5-year survival rate of 78.2%, compared with 36.3% in those whose tumors were positive for either one (P = 0.002). However, bcl-2 and p53 were not independent prognostic factors for survival. CONCLUSION: HER-2/neu and FASE are independent prognostic factor in stage I non-small cell lung cancer patients who expressed one or both markers.
PURPOSE: To evaluate the biological effect of retinoic acid on cultured human periodontal ligament cells. METHODS: Human periodontal ligament cells were cultured and challenged by retinoic acid with different concentrations. The cell morphology was observed under phase-contrast microscope; the cell proliferation activity was examined using MTT; the alkaline phosphatase activity was measured by enzyme kinetics method; the total amount of protein was assayed at different times. RESULTS: Retinoic acid enhanced alkaline phosphatase activity and had no effect on morphology, proliferation and total protein synthesis of periodontal ligament cells. CONCLUSION: Retinoic acid improves periodontal ligament cells to differentiate into osteoblast like cells.
AIM: To develop a Fab antibody against platelet GPIIb/IIIa. METHODS: A mouse anti-human GPIIb/IIIa monoclonal antibody (mAb) P140 was selected by the indirect immunofluorescence assay (IFA) and platelet aggregation inhibition test. The Fd and light chain genes were cloned from the hybridoma cells secreting the mAb P140. The genes of P140 Fab were inserted into plasmid p3MH to construct recombinant expression plasmid p3MH/P140kappa-Fd. After digestion with the restriction enzyme, the recombinant plasmid was transformed into E.coli XLI-Blue. The expressed product was purified by TALON metal affinity resin. Purified P140 Fab was characterized by SDS-PAGE, ELISA, Western blot and platelet aggregation inhibition test. RESULTS: SDS-PAGE analysis showed that relative molecular mass (M(r)) of P140 Fab was 47x10(3). The results of ELISA, Western blot and platelet aggragation inhibition test indicated that P140 Fab could specifically bind to platelet and inhibit platelet aggragation in dose-dependent manner. The mean value of IC(50) was 16.85 mg/L. CONCLUSION: A soluble anti-platelet GPIIb/IIIa antibody P140 Fab was prepared successfully, which lays the foundation for further clinical application.
OBJECTIVE: To explore the role of adhesion molecules in the pathogenesis of hypertension in obstructive sleep apnea-hypopnea syndrome (OSAHS). METHODS: The levels of serum soluble intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and L-selectin in 30 OSAHS patients accompanied by hypertension, 30 normotensive OSAHS patients and 30 healthy controls were measured by enzyme-linked immunosorbent assay (ELISA) method. The relationship of the concentration of ICAM-1, VCAM-1 and L-selectin with the polysomnogram (PSG) parameters was analyzed. RESULTS: The levels of serum soluble ICAM-1 [(601 +/- 406) microg/L, (513 +/- 244) microg/L, respectively] and VCAM-1 [(578 +/- 176) microg/L, (480 +/- 144) microg/L, respectively] were significantly higher in OSAHS accompanied by hypertension and normotensive OSAHS than those in the healthy controls [(355 +/- 119) microg/L, (310 +/- 163) microg/L, q = 4.78, 3.07; 9.09, 5.76, P < 0.01, respectively]. But the levels of serum L-selectin was not significantly different among the three groups (P > 0.05). The levels of serum VCAM-1 were significantly higher in OSAHS accompanied by hypertension than those in the normotensive OSAHS (q = 3.32, P < 0.05). The was not significantly different between the two groups (P > 0.05). There was a significantly positive correlation between the concentration of ICAM-1 and the apnea hyponea index (AHI) as well as microarousal index in all the 60 OSAHS patients with and without hypertension (r = 0.465, P < 0.01, r = 0.226, P < 0.05). There was a significantly negative correlation between the concentration of ICAM-1 and the lowest oxygen desaturation in all the 60 OSAHS patients with and without hypertension (r = -0.368, P < 0.01). CONCLUSION: The high level of serum VCAM-1 and ICAM-1 is an important risk factor for the development of hypertension in OSAHS patients.
OBJECTIVE: To explore the relationship between left ventricular hypertrophy (LVH) and serum insulin changes in normotensive patients. METHODS: Forty-two normotensive patients with LVH, who were free of hypertension, coronary artery disease and diabetes, were examined for fasting serum insulin, glucose and serum lipids, and the left ventricular mass (LVM) and left ventricular mass index (LVMI) were also measured with echocardiography, with 46 normal subjects serving as the control group. RESULTS: The levels of fasting triglyceride and insulin, as well as insulin resistance index (IRI), were higher in the LVH group than in the control group. Multifactor regression analysis showed that IRI was positively correlated to LVM and LVMI in LVH group (r=0.38, P<0.01; r=0.29, P<0.01). CONCLUSION: Hyperinsulinemia is closely correlated with LVH in these normotensive patients, and can be involved in the pathogenesis and progression of LVH.
OBJECTIVE: To evaluate the influence of minocycline on the proliferation and biosynthesis of human periodontal ligament cells (HPDLCs) in vitro. METHODS: Various concentrations of minocycline (1, 5, 20, 100, 500, 2 500 mg/L) were added to the medium of cultured HPDLCs respectively. After co-incubated for 2 days, cell morphology was observed under reverse microscope, cell proliferation activity was assayed using MTT, the total amount of protein was detected with Coumassie Bright Blue method and DNA synthesis was measured by (3)H-TdR. RESULTS: The presence of minocycline not exceeding 500 mg/L in the medium resulted in no morphological change of HPDLCs. Moreover, at a concentration range of 5 to 100 mg/L, minocycline significantly enhanced the proliferative activity and biosynthesis of HPDLCs (P < 0.01). However, higher concentration (2 500 mg/L) not only changed cell morphology under microscope, but also significantly inhibited cellular activity. CONCLUSIONS: The results suggest that proper doses of minocycline could promote biobehavior of HPDLCs, while higher concentrations of minocycline had cytotoxic effect which may intervene affect tissue repair and regeneration.
OBJECTIVE: To explore the role of the mutation of presenilin-1 exon 6 in pathogenesis of Alzheimer's disease(AD) patients. METHODS: Exon 6 of presenilin-1 was analyzed by use of polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and DNA analyzer technique in 2 patients with familial AD, 53 patients with sporadic DA, 60 patients with vascular dementia(VD) and 90 normal controls. RESULTS: Mobility shift of SSCP in exon 6 of presenilin-1 was detected in 2 cases with FAD, 4 cases with SDA and 1 case with VD. Two missense mutations were found in the patients by DNA sequence analysis, one mutation was 1123 nt C-->G(Cys 23 Trp) and the other was 1300 nt A-->C(Asp 200 Ala). CONCLUSION: Mutations in exon 6 of presenilin-1 existed in the patients with FAD and SDA, and the two missense mutations were probably pathological by nature.
OBJECTIVE: To investigate the feasibility of using immunohistochemical technique to detect the presence of fetal erythroblasts in the maternal circulation for prenatal diagnosis. METHODS: Maternal blood was obtained from 30 pregnant women at 8 to 26 weeks of gestation. Nucleated red blood cells (NRBCs) were separated with Percoll using a discontinuous density gradient method, and then smeared on microscope slides using cytocentrifugation. Slides were stained with antibody against the gamma-chain of fetal hemoglobin (HbF). All positive NRBCs were collected by micromanipulator under microscopic observation, and then amplified by improved primer extension preamplification(PEP). Sex and Duchenne's musclar dystrophy (DMD) genetic diagnosis were determined from a small aliquot of the PEP reaction. RESULTS: NRBCs stained with HbF were found in all of the blood from the 30 pregnant women at 8 to 26 weeks of gestation. 17 male fetuses and 13 female fetuses were detected in the 30 cases. These results coincided with those of induced labor or amniotic fluid control, and 8 fetuses at the risk of DMD were diagnosed. CONCLUSION: This diagnostic method using immunohistochemical technique to mark fetal NRBC shows good application prospects.
Insulin-like growth factor receptor 1 (IGF-1R) plays a critical role in oncogenic transformation (1). IGF-1R is overexpressed in some tumors including breast, lung, cervical, and Wilms' tumors (2-6). Upon binding of IGF-I or IGF-II, IGF-1R, a tyrosine kinase, phosphorylates tyrosine residues on two major substrates, IRS-1 and Shc, which subsequently signal through the Ras/Raf and PI 3-kinase/AKT pathways (7). Extensive literature has shown that when the IGF-1R signaling pathway is blocked by antisense, dominant negative truncation or neutralizing antibodies, cellular transformation and tumor formation in mice is inhibited (8-18). Small molecule kinase inhibitors represent a valid approach to inhibit activity and downstream signalling of IGF-1R. To date, few potent and selective small molecule inhibitors of IGF-1R kinase activity have been reported. We expressed the tyrosine kinase domain of IGF-1R (IGF-1R/TK) in insect cells and subsequently purified the partially activated IGF-1R/TK. A compound library has been screened using a homogeneous time-resolved fluorescence (HTRF) assay. The hits generated by HTRF were then evaluated in a 33P ATP streptavidin-Flashplate assay (Flashplate). There was approximately 78% hit congruence between the two assay formats. One compound, C100, inhibited the IGF-1R kinase activity with an IC50 of 1 microM. C100 also inhibited IGF-1R autophosphorylation, AKT and MAPK activations in cells. This inhibitor provides a useful tool for studying IGF-1R in cells.
In a laboratory experiment, Moina mongolica and Brachionus plicatilis were polycultured at four relatively inoculating densities, i.e., 0.06/0.30, 0.10/0.30, 0.30/0.30 and 0.60/0.30 (ind x ml(-1)/ind x ml(-1)), while M. mongolica monocultured at 0.06, 0.10, 0.30 and 0.60 ind x ml(-1) and B. plicatilis at 0.30 ind x ml(-1) were used as the control. Interspecific interference did exist between M. mongolica and B. plicatilis when these two species coexisted in a microcosm. In the polycultured microcosms, depressed population density of M. mongolica resulted from the coexistence of B. plicatilis, and M. mongolica maintained at extremely low density. In opposite, M. mongolica had negligibly negative influence on the population of B. plicatilis. Further experiment showed that the mortality of M. mongolica deprived of food for 120 h was 100%, while 90% of B. plicatilis survived after 144 h of food deprivation. The relatively strong capacity of B. plicatilis in tolerating starvation may be one of the important reasons for it wins the competition against M. mongolica.
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