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Biomedical subjects

Jing Liu

Publications and source records attributed to Jing Liu.

At least 127 records · Page 7Linked to original sources
PubMed2006

[Somitogenesis models and related genes in animals].

During embryonic development, many animals form a number of temporary structures along their anterior-posterior axis-somites. Cells in somites differentiate into sclerotome, which gives rise to vertebral column, dermatome, which gives rise to dermis, and myotome, which gives rise to skeletal muscle. During the past three decades, several models have been proposed to explain the formation of somites, including the clock and wavefront model, the reaction-diffusion type model, the clock and induction model, the clock and trail model, and others. These models, albeit not perfect, serve to explain different aspects of somitogenesis. Most of these models propose the concept of segmental clock. Studies on expression patterns of c-hairy 1 and c-hairy 2 in chick, l-fng in chick and mouse, and her 1 and Delta C in zebrafish have provided evidence for the existence of segmental clock.

Animals↗
PubMed2006

[Impact of multi-layer spiral CT angiography of bronchial artery and pulmonary artery in assessment of the main blood supply to the primary lung cancer].

OBJECTIVE: To investigate the blood supply of primary lung cancer (PLC) using CT angiography for bronchial artery (BA) and pulmonary artery (PA). METHODS: Thin-section enhanced multi-layer spiral CT (MSCT) were carried out in 147 primary lung cancer patients and 46 healthy subjects as control. Three-dimensional images of bronchial artery and pulmonary artery were obtained using volume render (VR) and multi-planar reconstruction (MPR) or maximum intensity projection (MIP) at the workstation, and their morphological findings and relationship with the mass were assessed. RESULTS: 136 primary lung cancer patients and 32 healthy controls were evaluated for at least one bronchial artery displayed clearly in VR. The detective rate of the bronchial artery was 92.5% and 69.6%, respectively. The bronchial artery caliber and the total section area of lesion side in lung cancer patients were significantly larger than that on the contralateral side and that of the control (P < 0.05). Bronchial artery on the lesion side in lung cancer was dilated and tortuous, directly penetrating into the mass with reticularly anastomosed branches. In the PLC patients, all PA were shown clearly with normal morphological image though crossing over the masses in 54 patients; In 25 PLC patients, the PA being essentially intact, was pushed around and surrounded the mass, giving the "hold ball" sign; In 40 other PLC patients, PA being also intact, the mass surrounded and buried the PA from the outside, crushing the PA flat resulting in an eccentric or centrifugal shrinkage, forming the "dead branch" sign; In the rest 28 patients, the PA was surrounded and even compressed, forming the "residual root" sign. CONCLUSION: Primary lung cancer patient shows dilated bronchial arteries and increased bronchial artery blood flow, whereas pulmonary arteries just pass through the mass or are compressed by the mass. It is further demonstrated that the bronchial artery, instead of the pulmonary artery, is the main vessel of blood supply to the primary lung cancer as shown by MSCT angiography of bronchial artery and pulmonary artery.

Adenocarcinoma↗
PubMed2006

[Relationships among human follicular fluid-induced acrosome reaction, sperm morphology and in vitro fertilization rates].

OBJECTIVE: To assess the relationships among human follicular fluid-induced acrosome reaction, sperm morphology and in vitro fertilization rates. METHODS: The relationships among human follicular fluid-induced acrosome reaction, sperm morphology and in vitro fertilization rates were investigated by Spearman rank correlation in 79 infertile couples. And the sperm morphology analysis was performed by crystal violet staining and based on strict criteria. RESULTS: A significant positive correlation was found between the percentage of human follicular fluid-induced acrosome reaction and that of normal sperm morphology (n = 49, r = 0.3763, P < 0.01), but no significant correlation was observed either between the percentage of human follicular fluid-induced acrosome reaction and in vitro fertilization rates or between that of normal sperm morphology and in vitro fertilization rates (n = 21, r = 0.2666, P > 0.05 and n = 50, r = 0.0018, P > 0.05, respectively). CONCLUSION: There is a significant positive correlation between the percentage of human follicular fluid-induced acrosome reaction and that of normal sperm morphology, but no such correlation either between the percentage of human follicular fluid-induced acrosome reaction and in vitro fertilization rates or between that of normal sperm morphology and in vitro fertilization rates.

Acrosome Reaction↗
PubMed2006

[Determination of time-weighted average concentration for vinyl chloride in the air of workplace].

OBJECTIVE: To establish a gas chromatographic method with carbon disulfide desorption for time-weighted average (TWA) concentration of vinyl chloride in the air of workplace. METHODS: Vinyl chloride in the air was sampled individually with activated charcoal tube. Vinyl chloride was desorbed by carbon disulfide for 30 minutes and analyzed by GC (FID). Time was used for qualitative analysis and peak area was for quantitative analysis. RESULTS: Linearity range was 0.0264-1.6896 mmol/L and the coefficient of correlation was 0.9999. Limit of detection: 1.2 ng (injection of 1microl). Relative standard deviation that expressed precision ranged from 3.8% to 6.7% for different concentrations. And average desorption efficiency of carbon disulfide was 90.77%. CONCLUSION: These indicators were corresponding to the Chinese guideline of the method for determination of toxic substances in workplace air and confirmed to be suitable for determining TWA concentration of vinyl chloride in workplace.

Air Pollutants, Occupational↗
PubMed2006

Waste water disinfection during SARS epidemic for microbiological and toxicological control.

OBJECTIVE: To evaluate the disinfection of wastewater in China. METHODS: During the SARS epidemic occurred in Beijing, a study of different disinfection methods used in the main local wastewater plants including means of chlorine, chlorine dioxide, ozone, and ultraviolet was carried out in our laboratory. The residual coliform, bacteria and trihalomethanes, haloacetic acids were determined after disinfection. RESULTS: Chlorine had fairly better efficiency on microorganism inactivation than chlorine dioxide with the same dosage. Formation of THMs and HAAs does not exceed the drinking water standard. UV irradiation had good efficiency on microorganism inactivation and good future of application in China. Organic material and ammonia nitrogen was found to be significant on inactivation and DBPs formation. CONCLUSION: Chlorine disinfection seems to be the best available technology for coliform and bacteria inactivation. And it is of fairly low toxicological hazard due to the transformation of monochloramine.

Acetates↗
PubMed2006

[Prolongation of the survival of skin allografts by intravenous injection of neuraminidase-treated donor bone marrow cells in rats].

OBJECTIVE: To optimize the best concentration of neuraminidase (Neu) that enhances the migration of neuraminidase (Neu)-treated donor bone marrow cells (dBMCs) to the liver, and observe the influence of short-term cyclosporin A(CsA) application combined with intravenous injection (i.v.) of Ne treated dBMCs on the survival of skin allografts. METHODS: The experiment consisted of two parts. For selection of an appropriate concentration of Neu, 26 female Wistar rats were randomly divided into four groups. The dBMCs were prepared by routine method and treated with four concentrations (0, 0.5, 1.0, 2.0 U/ml) of Neu at 37 degrees C for 30 min. The untreated and Neu-treated dBMCs were labeled by 99mTc, and injected via the tail veins to female Wistar rats in each group, respectively. After five hours, the radioactivity of various organs collected from sacrificed rats was measured by a gamma counter, and the values were expressed as percentage of total radioactivity of all organs from the same rat. To observe the survival of skin allograft, 23 male Wistar rats were randomly divided into control group, untreated dBMCs group and Neu-treated dBMCs group. All rats in each group were grafted with skin allografts from male Sprague-Dawley (SD) rats. The dBMCs from the same donor without and with Neu treatment by the concentration selected from the above experiment were injected via the tail veins of female Wistar rats in untreated dBMCs group and Neu-treated dBMCs group, respectively. Rats in untreated dBMCs group and Neu-treated dBMCs group received CsA (10 mg/kg) through intraperitoneal injection (i.p.) at 2 and 5 days post-grafting. Neither dBMCs or CsA were given in the control group. The survival of allograft skin in each group was checked and photographed daily after 5 days post operation. RESULTS: When the concentration of Neu was 1.0 U/ml, the percentage of dBMCs in liver was (75.3 +/- 9.8) %, which was obviously higher than that in 0 U/ml group [(58.9 +/- 4.2%)], (P < 0.01), indicating that the optimal concentration of Neu was 1.0 U/ml. The survival time of skin allografts in rats of Neu-treated dBMCs group was prolonged significantly in comparison with that of the rats in dBMCs group without Neu treatment (P < 0.01). The survival time in both dBMCs group and Neu-treated dBMCs group was longer that of control group (P < 0.01), and it was prolonged in Neu-treated dBMCs group compared with that in dBMC group. CONCLUSION: Administration of proper concentration of Neu can increase the affinity of dBMCs to the liver, and promote the Neu-treated dBMCs to migrate to liver. The intravenous injection of Neu-treated dBMCs combined with short-term CsA administration can delay the rejection of skin allografts in rats.

Animals↗
PubMed2006

[Relationship between single nucleotide polymorphisms of NRAMP1 gene and susceptibility to pulmonary tuberculosis in workers exposed to silica dusts].

OBJECTIVE: To explore the relationship between polymorphisms of natural resistance-associated macrophage protein 1 (NRAMP1) gene and genetic susceptibility of pulmonary tuberculosis (PTB) in workers exposed to silica dusts. METHODS: A 1:2 case control study of 61 male workers with PTB (50 silicosis patients and 11 unsilicosis workers) as the case group and 122 male PTB-free workers (100 silicosis patients and 22 unsilicosis workers) as the control group was conducted with the frequency matched for age of +/- 5 years, the job, the silica exposure, and the condition of cigarette smoking and alcohol drinking. The polymerase chain reaction-restrained fragment length polymorphism technique (PCR-RFLP) was used to detect the single nucleotide polymorphisms (SNPs) of NRAMP1 INT4 and D543N. RESULTS: There was a 2.73 times (95% CI: 1.32 approximately 5.64) increased risk of silicosis for individuals with C allele of NRAMP1 INT4 compared with individuals carrying homozygote (G/G), while SNPs of NRAMP1 D543N was not associated with PTB (P > 0.05). CONCLUSION: The G > C mutation of intron 4 of NRAMP1 gene might be a susceptible factor of silica for the workers exposed to PTB.

Aged↗
PubMed2006

[In vitro differentiation into megakaryocytes and generation of platelets from CD34+ cells of umbilical cord blood].

OBJECTIVE: To induce hematopoietic progenitor/stem cells of umbilical cord blood to differentiate into mature megakaryocytes and platelets in vitro and to investigate the mechanism of production of platelets. METHODS: The CD34+ cells were sorted from umbilical cord blood by magnetic activated cell sorting (MACS) and then cultured in vitro with optimized medium to be differentiated into mature megakaryocytes and platelets. The cultured cells and the platelet-like particles were isolated from the culture and were checked by the fluorescence-activated cell sorter (FACS), immunohistochemistry assays, light microscope,electron microscope and platelet aggregation tests. RESULTS: The cultured megakaryocytes were detected with proplatelets and both the cultured cells and the platelet-sized particles were found to have the same structure with the normal megakaryocytes and platelets by light and electron microscope. The immunohistochemistry assays revealed the cultured cells expressed GP II b III a with a positivity of 95% which was a special antigen for platelets and megakaryocytes. Culture-derived platelet-sized particles aggregated in response to thrombin as the plasma derived-platelets did. The cultured platelets had the same positivity of CD41 as the platelets from platelet rich plasma. CONCLUSION: The hematopoietic progenitor/stem cells can be induced to differentiate into purified and mature megakaryocytes and platelets. It provides a practical way to study the mechanism of platelets production.

Antigens, CD34↗
PubMed2006

[Fluorine removal efficiency of organic-calcium during coal combustion].

Effectiveness of calcium magnesium acetate (CMA) and calcium acetate(CA) as feasible HF capture were studied by means of fixed bed tube furnaces. The effects of temperature, particle diameter and Ca/S molar ratio on the fluorine removal efficiency were studied. By contract with CaCO3 at the same condition, we find that the HF capture effectiveness of those sorbents is superior to CaCO3, especially at high temperature. At 1 000 - 1 100 degrees C, the efficiency of fluorine removal during coal combustion of CMA is 1.68 - 1.74 times as that of CaCO3; the efficiency of fluorine removal during coal combustion of CA is 1.28 - 1.37 times as that of CaCO3.

Absorption↗
PubMed2006

[Resistance to HIV-1 infection of CD4 + T lymphocytes in vitro from chinese HIV-1 exposed seronegative individuals].

OBJECTIVE: To determine the relative resistance to HIV-1 infection of CD4 + T lymphocytes in HIV-exposed seronegative individuals (ESNs) in China. METHODS: HIV primary isolates were obtained from peripheral whole blood of HIV-infected persons. CD4 + T lymphocytes of Chinese ESNs were separated from peripheral blood mononuclear cells with magnetic cell sorting (MACS). The purified CD4 + T lymphocytes were cocultured with HIV primary isolates. The p24 level was detected and the culture medium was refreshed every 3 days within 2 weeks. RESULTS: For M tropic HIV strains, p24 level was significantly lower in ESN group than in control group (P < 0.05); for some M tropic HIV strains, even no p24 replicated in ESN group. However, T tropic virus strains had no significant difference between these two groups (P > 0.05). CONCLUSION: CD4 + T lymphocytes of Chinese ESNs may possess relative resistance to M tropic HIV strains, which may be one of the main influencing factors that result in ESN.

Adult↗
PubMed2006

[Background study of HIV-1 drug resistant mutations in treatment-naive patients in liaoning province].

OBJECTIVE: To collect background information on drug resistance mutations in treatment-naïve HIV-1 infected individuals in Liaoning Province. METHODS: Samples from 91 antiretroviral therapy-naïve patients were collected. The entire protease gene and 1-290 amino acids of the reverse transcriptase gene were amplified by nested PCR from provirus DNA and sequenced. The results were analyzed with HIVdb-Drug Resistance Algorithm, and genotypic resistance mutations were determined to particular anti-HIV drugs. RESULTS: Totally 91 sequences were obtained, 3 of which displayed M46I mutations in the protease gene. Minor resistance mutation rate to protease inhibitors was 100%, including types of L63P (60.4%), V77I (60.4%), M36I/V (31.9%), A71V/T (22.0%), L10I (8.8%), and K20R (6.6%). Only one sequence carried reverse transcriptase related resistance mutations M184I. CONCLUSIONS: About 4.4% of HIV-1 infected individuals in Liaoning Province carried strains with drug resistance mutations. Most treatment-naïve HIV-1 infected individuals in Liaoning Province were sensitive to the currently available antiviral medicines, but antiviral treatment must be in accordance with the strict procedures to keep better adherence and avoid the prevalence of drug-resistant strains.

Adult↗
PubMed2006

[Effects of vitamin C on apoptosis and proliferation inhibition of human peripheral blood mononuclear cells induced by deoxynivalenol in vitro].

OBJECTIVE: To explore the effects of Vitamin C (Vit C) on the apoptosis and proliferation inhibition of human peripheral blood mononuclear cells (HPBMCs) induced by deoxynivalenol (DON) in vitro. METHODS: The effects of Vit C pretreatment at different dosages (25 micromol/L and 100 micromol/L) on apoptosis, apoptosis related genes expression and proliferation inhibition of HPBMCs induced by DON were evaluated with cell culture, flow cytometric DNA analysis and Western blotting. RESULTS: Flow cytometry (FCM) analysis showed that the apoptosis rate of HPBMCs in 2000 microg/L DON group was (28.82 +/- 1.67)%, which was significantly higher than that in control group (14.07 +/- 0.70, P < 0.05). Compared with DON group, the apoptosis rate of HPBMCs in 25 micromol/L Vit C pretreatment group was significantly decreased (28.82 +/- 1.67)% vs (22.39 +/- 1.05)%, P < 0.05, while that in 100 micromol/L Vit C pretreatment group was obviously increased (36.07 +/- 2.92)%, P < 0.05. Western blotting analysis showed that the expression of Bax and Caspase-3 up-regulated by DON was markedly decreased, while the expression of Bcl-2 down-regulated by DON was increased by 25 micromol/L Vit C pretreatment (P < 0.05). 100 micromol/L Vit C pretreatment could further increase the expression of Bax and Caspase-3 of HPBMCs induced by DON, while no significant effects on the Bcl-2 expression induced by DON were seen. FCM analysis showed that the proliferation index of HPBMCs in Vit C pretreatment groups at different dosages was all dramatically increased as compared with that in DON groups (P < 0.05). CONCLUSION: 25 micromol/L Vit C pretreatment could at certain extent inhibit the apoptosis and reverse the abnormal expression of apoptosis related genes of HPBMCs induced by DON in vitro, while 100 micromol/L Vit C pretreatment could further increase the apoptosis rate of HPBMCs induced by DON. Vit C pretreatment could reverse the proliferation inhibition of HPBMCs induced by DON in vitro.

Apoptosis↗
PubMed2006

[Effects of vitamin C on the inhibition of human leucocyte antigen class I (HLA-I) expression of human peripheral blood mononuclear cells induced by deoxynivalenol in vitro].

OBJECTIVE: To explore the putative effects of Vitamin C (Vit C) on inhibition of human leucocyte antigen class I (HLA-I) expression of human peripheral blood mononuclear cells (HPBMCs) induced by deoxynivalenol (DON) in vitro. METHODS: The effects of Vit C on the changes of HLA-I expression of HPBMCs induced by DON in vitro were evaluated with cell culture, flow cytometry (FCM), Western blotting and immunocytochemical methods. RESULTS: FCM analysis showed that HLA-I expression of HPBMCs in DON treated cells was significantly lower than that in controls (FI 0.88 +/- 0.02 vs 1.00 +/- 0.03, P < 0.05). As compared with DON group, the HLA-I expressions of HPBMCs in the two Vit C (25 micromol/L and 100 micromol/L) pretreatment groups were all significantly increased (1.15 +/- 0.06 and 1.10 +/- 0.02 vs 0.88 +/- 0.02, P < 0.05). Exposure to different dosage of Vit C alone could dramatically increase the expression of HLA-I of HPBMCs in vitro as compared with that in the normal control (FI for 25 micromol/L and 100 micromol/L Vit C treatment group was 1.28 +/- 0.03 and 1.25 +/- 0.05 respectively, P < 0.05). Immunocytochemical results showed that the percentages of HLA-I positive expression of HPBMCs in Vit C pretreatment groups at different dosages were significantly higher than those in DON group (70.10 +/- 6.90)%, (64.50 +/- 5.50)% vs (42.20 +/- 4.30)%, P < 0.05. Western blotting confirmed the results of FCM and immunocytochemistry. CONCLUSIONS: Vitamin C pretreatment at different dosages could reverse at some extent the inhibitive effects of DON on HLA-I expression of HPBMCs.

Ascorbic Acid↗
PubMed2006

[Characteristics of T cell receptors recognizing antiphospholipid syndrome associated antigens].

To understand the characteristics of T cell receptors recognizing antiphospholipid syndrome associated antigen, the characteristics of T cells were analyzed using T cell receptor beta variable region (TCRbetaV) gene spectrotyping in a case of antiphospholipid syndrome (APS). The results indicated that in the case of APS there were 2 dominant T cell clones. The TCRbetaVs sequences of the 2 T cell clones showed the TCRbetaVs belonged to 8 and 23 gene families respectively. The peptides of third complementarity-determining regions (CDR3) in the TCRbetaVs were CASSLLVAGGPRAYNEQFFGPG and CASSLAGFGQPQHFGDG. Comparing the motifs in CDR3 with another autoimmune disease, the motif YNEQFFGPG in TCRbetaV8 and motif QHFGDG in TCRbetaV23 were identical with that of idiopathic thrombocytopenic purpura and systemic lupus erythematosus reported before. In conclusion, some T cell clones proliferating in these autoimmune diseases may recognize the same antigens.

Adult↗
PubMed2005

Codon optimization, expression, and characterization of an internalizing anti-ErbB2 single-chain antibody in Pichia pastoris.

Anti-ErbB2 antibodies are used as convenient tools in exploration of ErbB2 functional mechanisms and in treatment of ErbB2-overexpressing tumors. When we employed the yeast Pichia pastoris to express an anti-ErbB2 single-chain antibody (scFv) derived from the tumor-inhibitory monoclonal antibody A21, the yield did not exceed 1-2 mg/L in shake flask cultures. As we considered that the poor codon usage bias may be one limiting factor leading to the inefficient translation and scFv production, we designed and synthesized the full-length scFv gene by choosing the P. pastoris preferred codons while keeping the G+C content at relatively low level. Codon optimization increased the scFv expression level 3- to 5-fold and up to 6-10 mg/L. Northern blotting further confirmed that the increase of scFv expression was mainly due to the enhancement of translation efficiency. Investigation of culture conditions revealed that the maximal cell growth and scFv expression were achieved at pH 6.5-7.0 with 2% casamino acids after 72 h methanol induction. Secreted scFv was easily purified (>95% homogeneous product) from culture supernatants in one step by using Ni2+ chelating affinity chromatography. The yield was approximately 10-15 mg/L. Functional studies showed that the A21 scFv could be internalized with high efficiency after binding to the ErbB2-overexpressing cells, suggesting this regent may prove especially useful for ErbB2-targeted immunotherapy.

Amino Acid Sequence↗
PubMed2005

Determination of kinetic law for toxic metals release during thermal treatment of model waste in a fluid-bed reactor.

Accumulation of toxic metals generated by thermal treatment of municipal solid waste presents a serious threat to the environment. A study was carried out to investigate the kinetic law of toxic metal release from municipal solid waste during their thermal treatment. Both direct and inverse models were developed in transient conditions. The direct mathematical model of the fluid-bed reactor is based on Kunii and Levenspiel's two-phase flow model for Geldart Group B particles. The inverse model intends to predict the metal's rate of vaporization from its concentration in the outlet gas. The derived models were found to predict reasonably well the experimental observations. A method to derive the kinetic law of toxic metals release during fluidized bed thermal treatment of model waste from the global model and the experimental measurements is derived and illustrated. A first-order law was fitted for the mineral matrix, and a second-order law (simplified) was fitted for the realistic model waste. The kinetic law obtained in this way could be integrated in a global model of combustion of municipal solid waste in order to simulate the effects of operating parameters on the metal's behavior.

Hazardous Substances↗