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Biomedical subjects

Bing Zhang

Publications and source records attributed to Bing Zhang.

At least 109 records · Page 6Linked to original sources
PubMed2003

Roles of PLC-gamma2 and PKCalpha in TPA-induced apoptosis of gastric cancer cells.

AIM: To investigate the roles of PLCgamma2 and PKCalpha in TPA-induced apoptosis of gastric cancer cells. METHODS: Human gastric cancer cell line MGC80-3 was used. Protein expression levels of PLCgamma2 and PKCalpha were detected by Western blot. Protein localization of PLCgamma2 and PKCalpha was shown by immunofluorescence analysis under laser-scanning confocal microscope. Apoptotic morphology was observed by DAPI fluorescence staining, and apoptotic index was counted among 1,000 cells randomly. RESULTS: Treatment of gastric cancer cells MGC80-3 with TPA not only up-regulated expression of PLC-gamma2 protein, but also induced PLC-gamma2 translocation from the cytoplasm to the nucleus. However, this process was not directly associated with apoptosis induction. Further investigation showed that PKCalpha translocation from the cytoplasm to the nucleus was correlated with initiation of apoptosis. To explore the inevitable linkage between PLC-gamma2 and PKCalpha during apoptosis induction, PLC inhibitor U73122 was used to block PLC-gamma2 translocation, in which neither stimulating PKCalpha translocation nor inducing apoptosis occurred in MGC80-3 cells. However, when U73122-treated cells were exposed to TPA, not only PLC-gamma2, but also PKCalpha was redistributed. On the other hand, when cells were treated with PKC inhibitor alone, PLC-gamma2 protein was still located in the cytoplasm. However, redistribution of PLC-gamma2 protein occurred in the presence of TPA, no matter whether PKC inhibitor existed or not. CONCLUSION: PLC-gamma2 translocation is critical in transmitting TPA signal to its downstream molecule PKCalpha. As an effector, PKCalpha directly promotes apoptosis of MGC80-3 cells. Therefore, protein translocation of PLCgamma2 and PKCalpha is critical event in the process of apoptosis induction.

Apoptosis↗
PubMed2003

Degradation of retinoid X receptor alpha by TPA through proteasome pathway in gastric cancer cells.

AIM: To investigate and determine the mechanism and signal pathway of tetradecanoylphorbol-1, 3-acetate (TPA) in degradation of RXRalpha. METHODS: Gastric cancer cell line, BGC-823 was used in the experiments. The expression level of RXRalpha protein was detected by Western blot. Nuclear and cytoplasmic protein fractions were prepared through lysis of cell and centrifugation. Localization and translocation of RXRalpha were observed under laser-scanning confocal microscope through labeling specific anti-RXRalpha antibody and corresponding immunofluorescent antibody as secondary antibody. Different inhibitors were used as required. RESULTS: In BGC-823 cells, RXRalpha was expressed in the nucleus. When cells were treated with TPA, expression of RXRalpha was repressed in a time-dependent and TPA-concentration-dependent manner. Meanwhile, translocation of RXRalpha from the nucleus to the cytoplasm occurred, also in a time-dependent manner. When cells were pre-incubated with proteasome inhibitor MG132 for 3 hrs, followed by TPA for another 12 hrs, TPA-induced RXRalpha degradation was inhibited. Further observation of RXRalpha translocation in the presence of MG132 showed that MG-132 could block TPA-induced RXRalpha redistribution. Conversely, when RXRalpha translocation was inhibited by LMB, an inhibitor for blocking protein export from the nucleus, TPA could not repress expression of RXRalpha. CONCLUSION: TPA could induce the degradation of RXRalpha protein in BGC-823 cells, and this degradation is time- and TPA-concentration-dependent. Furthermore, the degradation of RXRalpha by TPA is via a proteasome pathway and associated with RXRalphatranslocation from the nucleus to the cytoplasm.

Carcinogens↗
PubMed2003

Allogeneic peripheral blood stem cell transplantation in the treatment of severe aplastic anemia and severe infection.

OBJECTIVE: To investigate the efficacy of allogeneic peripheral blood stem cell transplantation (PBSCT) in the treatment of severe aplastic anemia (SAA) and severe infection. METHODS: A patient with SAA and pseudomonas aeruginosa septicemia was treated with PBSCT from an HLA-identical sibling with cyclophosphamide (CY) and total body irradiation (TBI) for conditioning. The patient was infused with 20.3 x 10(8)/kg mononuclear cells including 61.0 x 10(6)/kg CD34(+) cells following the conditioning regimen. RESULTS: Twelve days after PBSCT, the absolute neutrophil count (ANC) of 1.0 x 10(9)/L was achieved, with platelet count > 50 x 10(9)/L at twenty days. The donor origin of engraftment was confirmed by polymerase chain reaction (PCR) analysis of short tandem repeats at the end of the first, sixth and twelfth month. The patient's body temperature dropped to normal level when her ANC reached 0.5 x 10(9)/L on day 10, and the bacterial culture of blood sample became negative subsequently. Symptoms and signs of acute or chronic graft versus host disease (GVHD) were not observed in 30 months after PBSCT. CONCLUSIONS: Hematopoiesis was reconstituted shortly after PBSCT. The combination of CY and TBI and the infusion of sufficient peripheral blood stem cells may contribute to the successful engraftment. PBSCT may be considered as the first choice when hematopoietic stem cell transplantation is needed for SAA patients complicated with severe infection.

Adult↗
PubMed2003

[Detection of minimal residual disease in Ph+/bcr-abl+ acute lymphoblast leukemia by cytogenetic analysis, nested-PCR and flow cytometry].

To explore a simple and sensitive method to detect minimal residual disease (MRD) in Ph(+)/bcr-abl(+) ALL patients, the bone marrow samples from 84 de novo ALL patients were detected by cytogenetic analysis, nested-PCR and flow cytometry (FCM). Cytogenetic analysis method is used to detect Ph chromosome, nested-PCR and FCM are used to detect bcr/abl mRNA and an abnormal B-cell differentiation pattern in de novo and complete remission (CR) patients, respectively. The results showed that Ph chromosome has not been found in 14 cases of CR; bcr/abl fusion gene was detected in 11 of 14 CR patients by nested-PCR (78.57%) and bcr/abl fusion gene was positive in 5 of 14 in CR patients (35.71%) by FCM. The sensitivity of nested-PCR was 10(-6)-10(-7), and that of FCM was 10(-4)- 10(-5). It is concluded that the cytogenetic analysis is not sensitive for MRD detection, and the sensitivity of nested-PCR is higher than that of FCM in detecting MRD.

Adolescent↗
PubMed2003

[The supplement therapy of microwave after endoscopic maxillary sinus surgery].

OBJECTIVE: To observe therapeutic effect of microwave eliminating the remnant lesion located at walls of maxillary sinus after endoscopic maxillary sinus surgery and the effect of postoperative. METHOD: Twenty-six cases (37 sites) were treated with microwave coagulating through enlarged ostium completely by means of 70 degrees endoscopy-guided. RESULT: The remnant lesion located at walls of maxillary sinus of 23 cases (33 sites) were eliminated without any complication and the effective eliminating rate was 89.2% (33/37). The infected local secretion of maxillary sinus of 17 cases (22 sites) were disappeared. CONCLUSION: The therapy of microwave by means of nasal endoscopy-guided can get rid of the lesion which is located at walls of the maxillary sinus to avoid the trauma caused by Caldwell-Luc operation, etc. It can improve the effect of the endoscopic sinus surgery.

Adolescent↗
PubMed2002

Childhood asthma in Beijing, China: a population-based case-control study.

China is the most populous country in the world. Few studies, however, have been conducted there to investigate the risk factors for childhood asthma. A population-based case-control study was conducted in Shunyi County, People's Republic of China, in January 1999 and March 2001 to investigate the issue. An increased risk of childhood asthma was associated with smoking by relatives in front of the mother while she was pregnant with the child (odds ratio (OR) = 1.3, 95% confidence interval (CI): 1.0, 1.6) and with smoking by relatives in front of the child (OR = 1.4, 95% CI: 1.1, 1.9). The risk increased with the increasing number of smokers and the total minutes of smoking by relatives in front of both the child and the mother while she was pregnant with the child. An increased risk was observed for use of coal for heating (OR = 1.5, 95% CI: 1.1, 1.9). Those who reported using coal for cooking without ventilation also had an increased risk (OR = 2.3, 95% CI: 1.5, 3.5). An increased risk was observed for those who reported having molds or fungi on the ceilings of their houses (OR = 1.8, 95% CI: 1.1, 2.9) or inside the child's room (OR = 1.8, 95% CI: 1.0, 3.2). An increased risk was also found for those having both a dog and a cat as pets (OR = 1.5, 95% CI: 1.0, 2.3) or for finding both cockroaches and rats inside their houses (OR = 1.8, 95% CI: 1.2, 2.8).

Age Distribution↗
PubMed2002

The Drosophila BMP type II receptor Wishful Thinking regulates neuromuscular synapse morphology and function.

Proper synaptic development is critical for establishing all aspects of neural function including learning, memory, and locomotion. Here, we describe the phenotypic consequences of mutations in the wishful thinking (wit) gene, the Drosophila homolog of the vertebrate BMP type II receptor. Mutations in wit result in pharate lethality that can be rescued by expression of a wit transgene in motor neurons but not in muscles. Mutant larvae exhibit small synapses, severe defects in evoked junctional potentials, a lower frequency of spontaneous vesicle release, and an alteration in the ultrastructure of synaptic active zones. These results reveal a novel role for BMP signaling in regulating Drosophila neuromuscular junction synapse assembly and activity and may indicate that similar pathways could govern vertebrate synapse development.

Animals↗
PubMed2002

A specific protein substrate for a deubiquitinating enzyme: Liquid facets is the substrate of Fat facets.

Eukaryotic genomes encode large families of deubiquitinating enzymes (DUBs). Genetic data suggest that Fat facets (Faf), a Drosophila DUB essential for patterning the compound eye, might have a novel regulatory function; Faf might reverse the ubiquitination of a specific substrate, thereby preventing proteasomal degradation of that protein. Additional genetic data implicate Liquid facets (Lqf), a homolog of the vertebrate endocytic protein epsin, as a candidate for the key substrate of Faf. Here, biochemical experiments critical to testing this model were performed. The results show definitively that Lqf is the key substrate of Faf in the eye; Lqf concentration is Faf-dependent, Lqf is ubiquitinated in vivo and deubiquitinated by Faf, and Lqf and Faf interact physically.

Adaptor Proteins, Vesicular Transport↗
PubMed2002

Amphiphysins: raising the BAR for synaptic vesicle recycling and membrane dynamics. Bin-Amphiphysin-Rvsp.

Amphiphysins, members of the BAR (Bin-Amphiphysin-Rvsp) protein super family, have been postulated to play a key role in clathrin-mediated endocytosis of synaptic vesicles (SVs). This review focuses on recent genetic studies of the role of amphiphysins in SV recycling and membrane morphogenesis. In the mouse, brain-specific amphiphysin I and II regulate, but are not essential for, SV recycling. The role of this regulation appears important, as mice deficient in these proteins have seizures and are deficient in learning and memory. In the fruit fly Drosophila melanogaster, amphiphysin is found in muscles and is enriched at postsynaptic membranes of neuromuscular junctions (NMJs); however, it does not play a role in SV recycling. Rather, amphiphysin in fly muscles appears to regulate the organization and structure of the muscle T-tubule system and possibly the subsynaptic reticulum. Amphiphysin is also involved in membrane organization in both neurons and non-neuronal cells in Drosophila. These studies reveal pleiotropic functions for amphiphysins in clathrin-mediated endocytosis and the regulation of membrane dynamics, perhaps through the actin cytoskeleton.

Animals↗
PubMed2002

A case-control study on risk of changing food consumption for colorectal cancer.

OBJECTIVES: To investigate the relative risk factor of food items for colorectal cancer in four time periods through a case-control study in a Chinese rural area. METHODS: Colorectal cancer patients diagnosed at a county cancer center, Hebei Province, China, and non-cancer outpatients with similar age, sex, and place of residence were selected for cases and controls, respectively. There were 102 (93.6%) colorectal cancer patients and 99 (90.8%) outpatients being the cases and controls, respectively in the present investigation, who agreed to be interviewed about their food intake, during a 20-year period, through a food frequency questionnaire. The risks of intake of different food items and lifestyle for colorectal cancer were compared between cases and controls. RESULTS: During the 20-year period, diets of both cases and controls changed with increase in intake of animal foods and fruits, and alcohol consumption tended to increase. In the food items, milk intake showed a protective effect in both males and females, and the odds ratios were 0.38 (95% CI 0.16-0.90) and 0.28 (95% CI 0.10-0.81) for males and females, respectively. A reduced risk of fruit intake could be seen in males, while a reduced risk of vegetables could be observed in females. Meat intake and saturated fats were the prominent risk factors for colorectal cancer in males and females, respectively. A comparison of life habits, showed that tea drinking had a consistent protective effect in females, and the odds ratios were 0.21 (0.08-0.58), 0.23 (0.08-0.67), 0.25 (0.10-0.64), and 0.11 (0.04-0.30) for periods of 20-, 10-, 5-years ago, and current time, respectively. CONCLUSIONS: These findings indicate that change in food consumption is strongly associated with a change in risk of colorectal cancer, and dietary meat has increased the risk of colorectal cancer. Increase in the consumption of milk and fruits may be a significant measure for colorectal cancer prevention in low-incidence areas.

Adult↗
PubMed2002

Characterization of early, chitin-induced gene expression in Arabidopsis.

Three genes (i.e., a zinc finger protein, a lectin-like protein, and AtMPK3), previously shown to respond to chitin elicitation in microarray experiments, were used to examine the response of Arabidopsis spp. to chitin addition. Maximum induction for all three genes was found upon addition of crab-shell chitin at 100 mg per liter. Threefold induction was found with a chitin concentration as low as 10(-4) mg per liter. The specificity of this response was examined using purified chitin oligomers (degree of polymerization = 2 to 8). The larger chitin oligomers (hexamer to octamer), were most effective in inducing expression of the three genes assayed. Gene induction was observed after the addition of 1 nM chitin octamer. The protein kinase inhibitors staurosporine and K252a effectively suppressed chitin-induced gene expression, while the protein phosphatase inhibitors calyculin A and okadaic acid induced the accumulation of mRNA in the absence of chitin. The phosphorylation event necessary for transmission of the chitin signal was completed within the first 20 min of chitin addition. The level of chitin-induced gene expression of the lectin-like protein and AtMPK3 was not significantly changed in mutants blocked in the jasmonic acid (JA, jar1)-, ethylene (ein2)-, or salicylic acid (SA, pad4, npr1, and eds5)-dependent pathway. In contrast, expression of mRNA for the zinc finger protein was reduced in the mutants affected in the JA- or SA-dependent pathway.

Arabidopsis↗
PubMed2002

Antitumor activities of human autologous cytokine-induced killer (CIK) cells against hepatocellular carcinoma cells in vitro and in vivo.

AIM: To characterize the anticancer function of cytokine-induced killer cells (CIK) and develop an adoptive immunotherapy for the patients with primary hepatocellular carcinoma (HCC), we evaluated the proliferation rate, phenotype and the antitumor activity of human CIK cells from healthy donors and HCC patients in vitro and in vivo. METHODS: Peripheral blood mononuclear cells (PBMC) from healthy donors and patients with primary HCC were incubated in vitro and induced into CIK cells in the presence of various cytokines such as interferon-gamma (IFN-gamma), interleukin-1 (IL-1), IL-2 and monoclonal antibody (mAb) against CD3. The phenotype and characterization of CIK cells were identified by flow cytometric analysis. The cytotoxicity of CIK cells was determined by (51)Cr release assay. RESULTS: The CIK cells were shown to be a heterogeneous population with different cellular phenotypes. The percentage of CD3+/CD56+ positive cells, the dominant effector cells, in total CIK cells from healthy donors and HCC patients, significantly increased from 0.1-0.13% at day 0 to 19.0-20.5% at day 21 incubation, which suggested that the CD3+ CD56+ positive cells proliferated faster than other cell populations of CIK cells in the protocol used in this study. After 28 day in vitro incubation, the CIK cells from patients with HCC and healthy donors increased by more than 300-fold and 500-fold in proliferation cell number, respectively. CIK cells originated from HCC patients possessed a higher in vitro antitumor cytotoxic activity on autologous HCC cells than the autologous lymphokine-activated killer (LAK) cells and PBMC cells. In in vivo animal experiment, CIK cells had stronger effects on the inhibition of tumor growth in Balb/c nude mice bearing BEL-7402-producing tumor than LAK cells (mean inhibitory rate, 84.7% vs 52.8%, P<0.05) or PBMC (mean inhibitory rate, 84.7% vs 37.1%, P<0.01). CONCLUSION: Autologous CIK cells are of highly efficient cytotoxic effector cells against primary hepatocellular carcinoma cells and might serve as an alternative adoptive therapeutic strategy for HCC patients.

Animals↗
PubMed2002

Oral pleconaril treatment of picornavirus-associated viral respiratory illness in adults: efficacy and tolerability in phase II clinical trials.

We evaluated the efficacy and tolerability of oral pleconaril, an anti-picornavirus agent, in treating acute viral respiratory illness (VRI) in two double-blind, placebo-controlled trials. Otherwise healthy subjects, 14 years of age or older, who presented within 36 h of VRI symptom onset, were randomized to pleconaril 400 mg or matching placebo in liquid (first trial) or tablet (second trial) formulations twice-daily (first trial only) or three-times daily for 7 days. The infected subjects from the corresponding active and placebo groups (three-times daily dosing regimens) were combined for analysis. Among the subset of subjects with proven picornaviral infection in both studies (42% of total enrolled), pleconaril 400 mg three-times daily (n = 323) reduced the time to alleviation of illness (no rhinorrhoea and other symptoms mild or absent for > or = 48 h) compared with placebo (n = 264) (median: 10.0 days for placebo and 8.5 days for pleconaril; P = 0.029). In addition, pleconaril reduced the time to a > or = 50% reduction from baseline in total symptom severity score (median: 4.5 days for placebo and 3.5 days for pleconaril; P = 0.038). Significant reductions in the number of tissues used for nose-blowing (20% reduction) and in nights of disturbed sleep (16% reduction) were also observed. Pleconaril was generally well tolerated; the liquid formulation caused gastrointestinal disturbance in all groups (diarrhoea 10-14%, nausea 5-9%, abdominal discomfort 6-8%), and tablets were associated with a greater incidence of nausea (3% for placebo versus 7% for pleconaril, P = 0.003). Pleconaril 400 mg administered three-times daily reduced the duration and severity of picornaviral VRI in adolescents and adults.

Administration, Oral↗