Biomedical subjects

Lei Pan

Publications and source records attributed to Lei Pan.

9 recordsLinked to original sources

PubMed2005

Effect of anti-tuberculosis therapy on liver function of pulmonary tuberculosis patients infected with hepatitis B virus.

AIM: To observe the effect of anti-tuberculosis therapy on liver function of pulmonary tuberculosis patients with hepatitis B virus (HBV) infection, and to compare the differences of liver function by two treatments of anti-tuberculosis. METHODS: Forty-seven TB patients with HBV infection and 170 TB patients without HBV infection were divided into HPBE(S) and HLAMKO treatment groups. Liver function tests before and after the treatments were performed once in 2 wk or monthly, and their clinical manifestations were recorded. RESULTS: The rate of hepatotoxicity occurred in 26 (59%) TB patients with HBV during anti-TB treatment, higher than that in 40 (24%) TB patients without HBV. Hepatotoxicity occurred in 66 out of 217 patients, and the incidence of liver dysfunction was 46.1% in HPBE(S) group, significantly higher than that in HLAMKO group (12.7%) (P<0.01). CONCLUSION: TB patients with HBV should choose HLAMKO treatment because of fewer hepatotoxicity.

Adult↗

PubMed2004

Process formation of the renal glomerular podocyte: is there common molecular machinery for processes of podocytes and neurons?

The renal glomerular podocyte exhibits a highly arborized morphology. In comparison with the neuron, which is the best studied process-bearing cell, the podocyte major processes share many cell biological characteristics with neuronal dendrites. Both podocytes and neurons develop microtubule-based thick processes with branching morphology and both have thin actin-based projections (i.e. podocyte foot processes and dendritic spines). Formation of podocyte processes and neuronal dendrites depends on the assembly of microtubules. Because the assembly of microtubules is regulated by phosphorylation of microtubule-associated proteins, inhibition of protein phosphatases abolishes and inhibition of protein kinases promotes process formation. Podocytes and dendrites also share the machinery of intracellular traffic of membranous vesicles, as well as cytoskeletal elements, which is indispensable for the elongation of these processes. Furthermore, these two cell types share expression of various molecules working for signal transduction, transmembranous transport and intercellular contacts. Such common gene expression implies a similar transcriptional regulation in these cells. Concerning the formation of podocyte foot processes and dendritic branches, actin filaments are thought to play a central role in orchestrating the function of various molecules and the regulation of actin assembly is necessary to establish and maintain such sophisticated cellular architecture. The molecular mechanism of foot process formation seems to include Rho family small GTP-binding proteins, which are known to be responsible for the establishment of dendritic branching morphology.

Actins↗

PubMed2004

Rho-ROCK signal pathway regulates microtubule-based process formation of cultured podocytes--inhibition of ROCK promoted process elongation.

BACKGROUND: Podocytes, renal glomerular visceral epithelial cells, have two kinds of processes, namely major processes containing microtubules (MTs) and foot processes with actin filaments (AFs). The present study investigated how MTs are organized by the Rho-ROCK signal transduction pathway during process formation of podocytes. METHOD: After induction of differentiation, podocytes of the conditionally immortalized mouse cell line were treated with Y-27632, a specific inhibitor of ROCK, and exoenzyme C3, an inhibitor of RhoA, as well as with forskolin whose effects include inhibition of RhoA, in order to inhibit the Rho-ROCK pathway. RESULTS: Inhibition of ROCK significantly enhanced the formation of thick processes containing MT bundles. Y-27632 promoted process formation even in the presence of latrunculin A which disrupts AFs, strongly suggesting that ROCK directly regulates MT assembly. Treatment with Y-27632 increased MT stability, and stabilized MTs preferentially localized in podocyte processes. Moreover, when treated with a combination of Y-27632 and forskolin, and with Y-27632 and C3 as well, podocytes developed not only MT-based thick processes but also AF-based thin projections. CONCLUSIONS: These data indicate a contribution of ROCK in MT organization to promote podocyte process formation, although it was originally thought to regulate AF assembly. AF-based thin projections seem to be induced mainly by inhibition of RhoA and ROCK. The present study reveals a significant role of the Rho-ROCK signal pathway in the reorganization of both MTs and AFs during process formation of podocytes.

ADP Ribose Transferases↗

PubMed2004

[The mechanism for up-regulation of HLA-I expression on HepG2 cells by HBV].

AIM: To explore the mechanism of up-regulation of HLA-I expression on HepG2 cells by wild type (WT) and nucleocapsid mutants(L97 and V60) of hepatitis B virus (HBV). METHODS: The HBV-stable expression vectors EBO-WT, EBO-L97 and EBO-V60 were transfected into HepG2 cells via the liposome mediation, respectively. The cells were assayed by semi-quantitative RT-PCR for HLA-A gene and antigen presentation-related genes LMP2, TAP1, and tapasin mRNA expression. Western blot was applied for analysis of HLA-I protein expression in the cells. RESULTS: HepG2 cells transfected by the 3 HBV expression vectors expressed HLA-A and TAP1, while there was no expression of HLA-A and only marginal expression of TAP1 in HepG2 cells transfected by control vector EBO. The expression level of HLA-A in the transfected cells decreased successively in the order of EBO-L97, EBO-WT and EBO-V60. There was no significant difference in the expression level of TAP1 between HepG2 cells transfected by the 3 HBV expression vectors. No detectable expression of LMP2 and tapasin was observed for all transfected cells. CONCLUSION: HBV can induce the expression of HLA-I molecule and TAP1 in HepG2 cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2004

[The relationship between cellular infection by Hantaan virus and expression of beta3 integrin].

OBJECTIVE: To investigate the relationship between cellular entry of Hantaan virus (HTNV) and expression of beta3 integrin in beta3-integrin-deficient and HTNV-insusceptible China hamster ovary (CHO) cells. METHODS: Eukaryotic expression vector encoding human integrin beta3 and eukaryotic expression vector harboring human integrin alphav or alphaIIb subunit cDNA were transfected into HTNV non-permissive CHO cells individually or collectively. Screening for stable transfectant clones was performed using G418 selective (culture medium. The exogenous gene expression was analyzed qualitatively and quantitatively by immunofluorescence assay (IFA) and flow cytometry (FCM). Various modified CHO cells and untransfected CHO cells were infected using HTNV A9. At various time points after infection, HTNV antigens in infected cells were detected qualitatively and quantitatively by IFA, FCM. RESULTS: Highly-effective surface expression of beta3 integrin was measured in CHO/alphavbeta3 and CHO/alphaIIbbeta3, while weaker surface expression was detected in CHO/beta3 (P < 0.05). Expression of alphav or alphaIIb integrin in the individually transfected group was significantly lower than in the cotransfected group (P < 0.01) and the sites of localization changed. In contrast, effective surface expression was not seen when pcDNA3 was transfected alone. The infection rate of CHO/alphavbeta3 (60.1%) and CHO/alphaIIbbeta3 (55. 9%) cells were significantly higher than that of CHO/beta3 (38.7%) cells, while the infection rate of CHO/beta3 was significantly higher than that of CHO/alphav, CHO/pcDNA3 and CHO cells respectively. There was a close relationship between the positive percentage of HTNV A9-infected cells and expression of beta3 integrin. CONCLUSION: These results indicated that cellular entry of HTNV was related to the expression of beta3 integrin.

Animals↗

PubMed2003

[Water storage characteristics of ground covers under three forests in Three Gorges area].

Through water holding experiments and the survey of ground covers under three forests (mixed forest of Quercus variabilis and Pinus massoniana, pure Quercus variabilis forest and pure Pinus massoniana forest) in Three Gorges Area, the hydrological characteristic parameters, e.g., maximum water holding capacity and water absorption speed, were measured. The results showed that the maximum water holding capacity of moss under pure Quercus variabilis forest is the highest (303.1% of its dry weight), that under mixed forest of Quercus variabilis and Pinus massoniana was 283.8%, and that under pure Pinus massoniana forest was 242.3%. The maximum water holding capacity of litter under mixed forest stand of Quercus variabils and Pinus massoniana was 282.2% of its dry weight, that under pure Quercus variabilis forest is 262.5%, that under pure Pinus massoniana forest was 239.3%. The equation between water absorption speed of ground cover and its immersed period could be S = kt(n). The results also showed that when the forests were all in mid-age, the water holding ability of the mosses was higher than that of the litters under the same forest. The ground cover's variation with its immersed period had no relation to forest types.

Absorption↗

PubMed2003

[Induction of IgG and IgM production by Epstein-Barr virus protein].

AIM: To detect the production of IgG and IgM by cultured umbilical blood B cell stimulated by UV and heat-inactivated Epstein-Barr virus (EBV). METHODS: Mononuclear cells were isolated routinely from umbilical blood, then monocytes, NK cells and cytotoxic T cells were eliminated by L-leucine methy ester method; remained T cells were eliminated by AET-SRBC rosette method. The purified B cells were treated with UV or heat-inactivated EBV respectively and cultured in complete IMDM. The IgG and IgM in the supernatant were detected by ELISA. RESULTS: The IgG and IgM production(A value) in UV-inactivated EBV group increased from 18th day to 30 th day after stimulation compared with the baseline. The A value of all time points in heat-inactivated EBV group had no significant difference. CONCLUSION: UV-inactivated EBV may induce IgG and IgM production with a time-effect relationship, suggesting that EBV protein is a key component of stimulating Ig production. This result provide the basis for the further researching the effects of functional EBV protein on the production of natural autoantibodies (NAA).

B-Lymphocytes↗

PubMed2003

[Construction of human integrin beta3 subunit eukaryotic expression vector and efficient surface expression of integrin alphaIIbbeta3].

AIM: To establish efficient surface expression of Homo sapiens integrin alphaIIbbeta3 in beta3-integrin-deficient and HV-insusceptible CHO cells, so as to lay the foundation for the further study of cellular entry of hantavirus mediated by beta3 integrins. METHODS: Eukaryotic expression vector pcDNA3.1-beta3 harboring ORF region of human integrin beta3 subunit cDNA was constructed, then pcDNA3.1-beta3 and eukaryotic expression vector pBJ1-alphaIIb containing human integrin alphaIIb subunit cDNA were transfected into CHO cells alone or together. The expression of exogenous genes were analyzed by indirect immunofluorescence assay (IFA). RESULTS: The eukaryotic expression vector pcDNA3.1-beta3 was constructed successfully. IFA examination showed that surface expression of integrin alphaIIb beta3 was highly effective in cotransfection group, while surface expression was weak on CHO cells transfected with pcDNA3.1-beta3 alone,and no effective surface expression was found in pBJ1-alphaIIb-transfected group. CONCLUSION: Efficient surface expression of integrin alphaIIb beta3 requires expression of both subunits.

Animals↗

PubMed2002

[Value of long-distance fetal heart rate monitoring on the pre-partum health care of the pregnant woman with umbilical cord loops].

OBJECTIVE: To explore the value of the long-distance fetal heart rate (FHR) monitoring on the pre-partum health care of self-monitoring at home for pregnant woman with the umbilical cord loops. METHODS: The umbilical cord loops was diagnosed by ultrasonography. In the study group, 896 pregnant women with the umbilical cord loops accepted long-distance FHR monitoring and the count of fetal movement (FM) as family-self monitoring methods, while in the control group, 1 914 pregnant women with the umbilical cord loops used the count of FM only as family-self monitoring method. Abnormal non-stress test (NST), variable deceleration, fetal distress, neonate asphyxia, fetal death, stillbirth, operative delivery rate were analyzed between the study and control group retrospectively. RESULTS: The incidence of NST reactive pattern and non- reactive pattern and the variable deceleration in long-distance FHR monitoring of the study group were significantly higher than those in routine FHR monitoring. The incidence of fetal distress in the study group (35.0%) was significantly higher than that in the control group (30.9%), while the incidence of neonatal asphyxia in the study group (3.5%) was significantly lower than that in the control group (5.6%). The incidence of outside hospital fetal death in the study group (0.1%) was significantly lower than that in the control group (0.8%). There were no significant differences of cesarean section rate, forceps or vacuum extractor delivery between the two groups (P > 0.05). CONCLUSIONS: This study suggested that the high variable rate in the long-distance FHR monitoring curve was related to the incidence of the fetal distress. It didn't increase the cesarean section rate and vaginal operative delivery rate, but decreased the neonatal asphyxia and outside hospital fetal death rate. The long-distance FHR monitoring combined with the count of FM may be a better family-self monitoring method for the pregnant women with the umbilical cord loops.

Cesarean Section↗