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Biomedical subjects

G Qian

Publications and source records attributed to G Qian.

At least 19 recordsLinked to original sources
PubMed2001

Recovery of heavy metals and stabilization of spent hydrotreating catalyst using a glass-ceramic matrix.

Chemical analysis of spent Co/Mo/gamma Al(2)O(3) catalyst revealed the presence of carbon, molybdenum, sulfur, vanadium and cobalt at levels of 16.0, 10.9, 7.3, 4.6 and 4.0 wt.%, respectively. It was found that calcination at 500 degrees C provides an effective solution for the removal of carbon and sulfur and this generates the oxide form of the heavy metals. The removal of these heavy metals can be achieved through a two-stage leaching process. During the first stage, in which concentrated ammonia is used and it has been found that this process can be successful in removing as much as 83% (w/v) Mo. In a second stage, it was found that using 10% (v/v) of sulfuric acid, it was possible to account for up to 77% (w/v) Co and 4% (w/v) Mo removal. Leaching test results indicated that the vanadium present in the heated spent catalyst was almost stabilized but the molybdenum and cobalt were not. The combination of two solid wastes, ladle furnace slag (LFS) and treated residue of spent catalyst, could be used for making a high value-added anorthite glass-ceramic materials. Further leaching tests showed that ceramic glass materials provided a very effective method of Co, Mo and V heavy metals stabilization resulting in a product with a possible commercial value.

Aluminum Silicates↗
PubMed2001

Adolescent smoking in Wuhan, China: baseline data from the Wuhan Smoking Prevention Trial.

BACKGROUND: This study reports the prevalence of adolescent smoking in the urban and rural areas of Wuhan, China, the capital of Hubei Province, on the Yangtze River in central China. METHODS: Smoking behavior was examined by age, gender, and urbanicity as part of the Wuhan Smoking Prevention Trial. Subjects included 6994 seventh- to ninth-grade students attending 22 randomly selected schools in urban and rural districts. Outcome measures included lifetime smoking, past-30-day smoking, established smoking (>100 cigarettes in lifetime), and susceptibility to smoking (absence of a firm commitment not to smoke). RESULTS: Lifetime smoking prevalence was 47% among boys and 18% among girls. Past-30-day smoking prevalence was 16% among boys and 4% among girls. Established smoking prevalence was 2% among boys and 0% among girls. The prevalence of susceptibility to smoking was 31% among boys and 10% among girls. Smoking increased significantly with age (p<.0005). Susceptibility was more prevalent in rural areas than in urban areas (p<.05), but there were no urban-rural differences in lifetime, past 30-day smoking, or established smoking. Trend analyses revealed that smoking increased with age more rapidly among boys than among girls (p<.05). Smoking was more prevalent among rural boys than among urban boys, but it was more prevalent among urban girls than among rural girls (p<.05). CONCLUSIONS: Adolescent smoking is a significant public health problem in China. Boys are at particularly high risk, as are girls living in urban areas. Effective smoking prevention programs for adolescents, as well as restrictions on tobacco industry marketing and youth access to tobacco, are needed to prevent tobacco-related morbidity and mortality in China.

Adolescent↗
PubMed2001

Robust structure from motion estimation using inertial data.

The utility of using inertial data for the structure-from-motion (SfM) problem is addressed. We show how inertial data can be used for improved noise resistance, reduction of inherent ambiguities, and handling of mixed-domain sequences. We also show that the number of feature points needed for accurate and robust SfM estimation can be significantly reduced when inertial data are employed. Cramér-Rao lower bounds are computed to quantify the improvements in estimating motion parameters. A robust extended-Kalman-filter-based SfM algorithm using inertial data is then developed to fully exploit the inertial information. This algorithm has been tested by using synthetic and real image sequences, and the results show the efficacy of using inertial data for the SfM problem.

Journal Article↗
PubMed2001

Ultrasonographic texture analysis of parenchymatous organs by the four-neighborhood-pixels algorithm: clinical experiment.

OBJECTIVE: The parenchyma of organs such as liver, thyroid, and mammary gland during climacterium have common ultrasonographic textural features, which together form what we call small-dot-structure texture. To study this texture we designed the 4-neighborhood-pixels algorithm, an ultrasonographic texture analysis algorithm. The objective of this study was to confirm whether the 4-neighborhood-pixels algorithm can reflect the features of small-dot-structure texture. METHODS: A changed small-dot-structure texture and 3 other textures were compared with the normal small-dot-structure texture in 4 groups, and a histogram algorithm was used for contrast with the 4-neighborhood-pixels algorithm. RESULTS: The 4-neighborhood-pixels algorithm could reflect all the textural differences, but the histogram algorithm could reflect only some of them. CONCLUSIONS: The 4-neighborhood-pixels algorithm is a good algorithm for analyzing ultrasonographic small-dot-structure texture. Not only can it reflect changes in the small-dot-structure texture, but it can also differentiate between small-dot-structure and non-small-dot-structure textures.

Adipose Tissue↗
PubMed2001

Changes and significance of circulating hepatocellular carcinoma cells in recurrent hepatocellular carcinoma patients after combined treatment.

OBJECTIVE: To study the changes and significance of circulating hepatocellular carcinoma cells in recurrent hepatocellular carcinoma (HCC) patients after combined treatment of transarterial chemo-embolization(TACE) and percutaneous ethanol injection(PEI). METHODS: We detected 19 blood samples from the recurrent HCC patients by nested RT-PCR to find out AFP mRNA before and after the treatment. RESULTS: There were 7 patients with AFP mRNA positive before treatment (36.8%), and none of patients with AFP mRNA positive after treatment. CONCLUSIONS: Combined treatment of TACE and PEI can effectively eliminate circulating hepatocellular carcinoma cells and thereby prevent metastasis and recurrence of HCC.

Adult↗
PubMed2001

[Impact of quantitative and qualitative pathogen culture on the outcome of ventilator-associated pneumonia].

OBJECTIVE: To evaluate the impact diagnostic methods with either quantitative culture (QC) or qualitative routine culture (RC) on the outcome of VAP. METHODS: A prospective, controlled clinical trial in 93 consecutive VAP episodes of 31 patients receiving mechanical ventilation was conducted. VAP episodes were randomly and crossly divided into QC (43 episodes, underwent FOB-PSB-QC) and RC group (50 episodes, underwent ETA-RC). Empirical antibiotic treatment was given according to the attending physician and modified according to the results of culture and sensitivity. The outcomes of VAP were assessed. RESULTS: There were no differences with regard to mortality, super-infection rate, antibiotic resistance rate and cost of antibiotics when comparing QC versus RC diagnostic methods and management based on two diagnostic strategies. Inappropriate initial empirical antibiotic treatment led to a higher mortality (17.7%) when compared with those with appropriate treatment. CONCLUSION: The present study demonstrates that the outcome of VAP is probably more dependent on the adequacy of the initial antibiotic treatment than on the use of either diagnostic sampling.

Aged↗
PubMed2001

[The influence of dexamethasone on mRNA expression of interleukin-5, interleukin-3 and granulocyte-macrophage colony-stimulating factor receptors in eosinophils of guinea pig asthma model].

OBJECTIVE: To investigate the iufluence of dexamethasone (DM) on expression of interleukin-5 receptor alpha(IL-5R alpha), interleukin-3 receptor alpha (IL-3R alpha), granulocyte-macrophage-colony-stimulating factor receptor alpha(GM-CSFR alpha) and common beta receptor (beta cR) in bronchalveolar lavage fluid (BALF) eosinophils in guinea pig asthma model, and to study the mechanism of promotion effect of steroid on eosinophil apoptosis. METHODS: 18 guinea pigs were divided into three groups randomly, normal control group, asthma group and DM-treated group. Asthma models of guinea pig were sensitized by ovalbumin(OVA). Hypodense EOS (HEOS) and normodense EOS (NEOS) were purified from BALF by gradients of percoll. Apoptosis was detected by method of TdT-mediated dUTP nick end labeling. The mRNA expression of IL-5R alpha, IL-3R alpha, GM-CSFR alpha and common beta receptor (beta cR) in eosinophils were measured by RT-PCR and in situ hybridization. RESULTS: Apoptosis of HEOS and NEOS in asthma group(4.0 +/- 2.0 and 3.0 +/- 2.0, respectively) were significanteylower than normal group(8.0 +/- 2.0 and, 7.0 +/- 2.0 respectively, P < 0.01), while the numbers of EOS cells (75.2 +/- 12.6 and 50.7 +/- 11.2, respectively) were significantly higher than normal group (4.8 +/- 1.5 and 9.5 +/- 2.6, respectively, P < 0.01). The BALF HEOS and NEOS of asthma group were remarkably reduced after DM treatment (14.8 +/- 8.0 and 20.0 +/- 7.0, respectively, P < 0.01), Eosinophils apoptosis in DM-treated group (24.0 +/- 5.0 and 22.0 +/- 4.0, respectively) was remarkably higher than those in asthma group (P < 0.01); The expressions of IL-5R alpha, IL-3R alpha, GM-CSFR alpha mRNA of BALF EOS of asthma group were significantly lower, but the expression of beta cR mRNA was significantly higher than those of normal group(P < 0.01, 0.05). The expressions of IL-5R alpha, IL-3R alpha, GM-CSFR alpha mRNA in EOS of DM-treated group were significantly higher, while the expression of beta cR mRNA were significantly lower than those of asthma group (P < 0.01, 0.05). CONCLUSIONS: DM promote the apoptosis of BALF EOS of guinea pigs asthma models. and reduce EOS infiltration in lung of guinea pigs asthma models. It also decreased the effect of IL-5, IL-3 and GM-CSF and promoted the apoptosis of lung EOS through inducing the mRNA expression of their specific alpha chain and reducing the mRNA expression of the common beta chain.

Animals↗
PubMed2001

[Construction of a subtracted cDNA library of differentially expressed genes in human normal liver tissue and primary hepatocellular carcinoma tissue].

OBJECTIVE: To construct a subtracted cDNA library of differentially expressed genes in human normal liver tissue and primary hepatocellular carcinoma (HCC) tissue. METHODS: Using the suppression subtractive hybridization (SSH), a novel technique has been described recently. cDNA fragments of missing or low expressing tumor suppressor genes in HCC tissue were isolated using paracancerous normal liver tissue and HCC tissue as targets. Then these cDNA fragments were directly inserted into T/A cloning vector to set up the subtractive library. Amplification of the library was carried out with transformation of E.coli by high voltage electroperforation. One hundred positive bacteria clones were randomly picked and identified using enzyme restriction method. RESULTS: The amplified library contained more than 4,000 positive bacteria clones. Random analysis of 100 clones with enzyme restriction method showed that all clones contained 200-600 bp inserts. CONCLUSIONS: A subtracted cDNA library of differentially expressed genes in human normal liver tissue and HCC tissue is constructed successfully with SSH and T/A cloning techniques. The library is efficient and lays solid foundation for screening and cloning new and specific missing or low expressing tumor suppressor genes of HCC.

Carcinoma, Hepatocellular↗
PubMed2001

[Correlation of endotracheal tube biofilm and recurrent ventilator-associated pneumonia with Pseudomonas aeruginosa].

OBJECTIVE: To determine the correlation of endotracheal tube biofilm (ETT-BF) and recurrent ventilator-associated pneumonia with Pseudomonas aeruginosa (PA-VAP) in long-term ventilation patients. METHODS: Pulsed-field gel electrophoresis (PFGE) of Spe I enzyme-restricted chromosomal DNA was performed to identify the DNA patterns of Pseudomonas aeruginosa from ETT-BF, pharynx and lower respiratory tract secretion in 15 VAP patients. The chromosomal DNA fingerprint profile of each strain was compared with those from all other strains to calculate the similarity by using the correlation coefficient. The strains were then grouped and groups were depicted as a dendrite using the average clustering algorithm. RESULTS: When bacteria has been isolated from ETT-BF, the same DNA pattern species are isolated from the lower respiratory tract secretion in 7 of 15 patients. Recurrent PA-VAP is caused by closely related and indistinguishable isolates in 6 of 15 patients. All PEGE patterns from 9 patients are different from one another (correlation coefficient < 31.2%). CONCLUSIONS: The close pathogenic relationship between ETT-BF and lower airway secretion suggests that adhesive colonization of ETTs may be an important factor in the pathogenesis of VAP.

Aged↗
PubMed2001

[Changes of L-selectin expression on polymorphonuclear leukocytes and its role during polymorphonuclear leukocytes sequestration in lungs of rats with acute lung injury].

OBJECTIVE: To explore the changes of L-selectin protein expression on peripheral blood polymorphonuclear leukocytes (PMN) and their role during PMN sequestration in the lungs of rats with acute lung injury (ALI). METHODS: The model of ALI in rat was established by intravenous injection of E. Coli endotoxin (ET). The protein expression of L-selectin on peripheral blood PMNs was measured by immunofluorescence and flow cytometry. Myeloperoxidase (MPO) enzyme analysis and histology were employed to estimate the quantity of PMN sequestration in lungs of rats during ALI. RESULTS: (1) The protein expression of L-selectin on PMN after injection of ET (7.8 +/- 1.6) was all significantly lower than that in control group (10.5 +/- 2.1, P < 0.05). (2) MPO activity increased significantly after injection of ET in comparison with the control group [0.069 +/- 0.011) U/mg lung tissue, P < 0.01]. The difference was not significant between the fucodin treated 5 min group [(0.391 +/- 0.071) U/mg lung tissue] and ET-treated 5 min group [(0.359 +/- 0.074) U/mg lung tissue]. But MPO activity was significantly lower in fucodin-treated 15 min group [(0.396 +/- 0.061) U/mg lung tissue] than that in ET-treated group at same time point [(0.490 +/- 0.069) U/mg lung tissue, P < 0.05]. CONCLUSIONS: (1) In physiological state, L-selectin are consistently expressed on the surface of PMN membrane. The protein expression of L-selectin on PMNs reduces rapidly after injection of ET and is the lowest at 15 min, then gradually increases. (2) The early stage of PMN sequestration in lungs is not dependent on L-selectin, but L-selectin is still important for maintaining a continual PMN sequestration in lungs of rats with ALI.

Animals↗
PubMed2000

[Effect of hypoxia and carbon monoxide on rat pulmonary arterial smooth muscle cell].

OBJECTIVE: To investigate the effect of carbon monoxide on rat pulmonary arterial smooth muscle cell (VSMC). METHODS: Three groups were randomly divided, (1) Normoxia group(N), (2) Hypoxia group(H), (3) 3% CO + 1% O2 group (CO + H), then tested by immunocytochemical analysis 3H-TdR in incorporation. RESULTS: (1) Hypoxia initiated the chang of VSMC from contractile phenotype to synthetic phenotype, the endoplasmic reticulum became dilated, the mitochondria became swollen and myelin figure appeared. alpha-actin and muscle fiber decreased. The form of VSMC in CO + H was similar to that in N. (2) Intracellular Ca2+ level of VSMC in H [4 h, 8 h, 12 h, 24 h, 36 h were (382.00 +/- 37.92) mmol/L, (456.00 +/- 53.76) mmol/L, (517.00 +/- 47.34) mmol/L, (608.00 +/- 35.92) mmol/L, (567.00 +/- 46.72) mmol/L, respectively] increased significantly(P < 0.01) than in N[4 h was(319.00 +/- 47.45) mmol/L], but that in CO + H increased slightly. (3) cAMP and cGMP level of VSMC in H increased significantly, cAMP of VSMC in CO + H increased significantly [2 h, 8 h, 12 h, 24 h were (1.87 +/- 0.36) pmol/mg protein, (2.16 +/- 0.36) pmol/mg protein, (2.36 +/- 0.41) pmol/mg protein, (2.12 +/- 0.39) pmol/mg protein, respectively] but cGMP of VSMC in CO + H increased slightly[2 h, 8 h, 12 h, 24 h were (0.52 +/- 0.21) pmol/mg protein, (0.58 +/- 0.21) pmol/mg protein, (0.60 +/- 0.24) pmol/mg protein, (0.68 +/- 0.29) pmol/mg protein, respectively]. CONCLUSION: Hypoxia may promote the proliferation of VSMC by second messenger system and CO in low desities can depress the action of hypoxia partly by Ca(2+)-cGMP system or by the expression of E2F-1 gene.

Animals↗
PubMed2000

Changes in serum ammonia concentration in cirrhotic patients with Helicobacter pylori infection.

OBJECTIVE: To study whether liver cirrhosis associated with Helicobacter pylori (H. pylori) infection will induce increased serum ammonia and whether the peripheral serum ammonia reflects the level of portal vein serum ammonia. METHODS: Blood was taken from the portal vein and the cubital vein in cirrhotic patients with and without H. pylori infection and non-cirrhotic patients (splenic rupture) with and without H. pylori infection, and the serum ammonia was measured. RESULTS: The mean levels of serum ammonia in the group of cirrhotic patients with H. pylori infection were 167.82 +/- 8.97 mumol/L (portal vein) and 142.2 +/- 13.35 mumol/L (cubital vein). They were increased significantly as compared with cirrhotic patients without H. pylori infection (47.68 +/- 12.03 mumol/L portal vein and 37.23 +/- 7.04 mumol/L cubital vein), and also compared with the groups of splenic rupture patients with and without H. pylori infection (P < 0.01). There was no significant difference between the serum ammonia level of the cubital vein and portal vein (P > 0.05). CONCLUSIONS: H. pylori infection can induce an increase in serum ammonia in patients with liver dysfunction, and the peripheral serum ammonia measurement may replace the portal vein serum ammonia as a monitoring method. Eradication of H. pylori in cirrhotic patients may prevent hepatic encephalopathy (HE).

Ammonia↗
PubMed2000

[Effects of dexamethasone on apoptosis and expression of Fas/FasL system in lung tissues of ALI rats].

OBJECTIVE: To determine whether apoptosis occurs in the lung tissues from rats with acute lung injury (ALI), and observe protective effects of dexamethasone by regulating apoptosis of lung tissues in rats with ALI. METHODS: By using TUNEL, in situ hybridization, SqRT-PCR and immunocytochemistry techniques, apoptosis and Fas, FasL expression were studied during early phase of ALI in rats. RESULTS: LPS leads to the rapid appearance of apoptosis in alveolar epithelial cells and pulmonary vascular endothelial cells at early stage of ALI in rats. The expression of Fas, FasL mRNA and protein was up-regulated in lung tissues of rats with ALI. The administration of dexamethasone suppressed apoptosis as well as expression of Fas, FasL mRNA and protein, inhibited TNF-alpha production and abated lung injury. CONCLUSIONS: The excessive apoptosis and Fas/FasL system may play a role in the pathogenesis of LPS-induced ALI in rats. The protective effects of dexamethasone include inhibiting inflammatory mediators production, suppressing the activation of Fas/FasL system and apoptosis in lung tissues of ALI rats.

Animals↗
PubMed2000

[Malignant transformation of mouse embryonic fibroblast induced by mitochondrial DNA fragments].

OBJECTIVE: To investigate the malignant transforming effect and mechanism of mitochondrial DNA (mtDNA) fragments. METHODS: Tumorigenicity of mtDNA-transformed mouse embryonic fibroblast (NIH3T3) in nude mice was studied using transgenic techniques. Transformed tumors were detected by pathological examination and hybridization signals of mtDNA probe were analyzed by fluorescence in situ hybridization (FISH) techniques. RESULTS: Hybridization signals were observed on the nuclei of 18% - 20% NIH 3T3 cells 1 week after mtDNA fragments transforming. Tumor from mtDNA-transformed NIH 3T3 cells was developed in all 8 nude mice (8/8) respectively 2 weeks after the transformation. The pathological characteristics of the tumors developed were similar to that of fibrosarcoma. CONCLUSIONS: Auto-integration of mtDNA fragments into nuclear genome is a new factor involved in carcinogenesis.

Animals↗
PubMed2000

[Experimental study on suppressive effect of ginkgo extract on adhesion of vascular endothelial cell to monocyte induced by minimally modified low density lipoprotein].

OBJECTIVE: To observe the effect of Ginkgo extract on the interaction between minimally modified low density lipoprotein (MM-LDL) induced human umbilical vein endothelial cell (HUVEC) and U937 monocyte-like cell line. METHODS: The adhesive percentage between HUVEC and U937 by counting and the expression of VCAM-1, ICAM-1, P-selectin by ELISA. RESULTS: Treatment of HUVEC with MM-LDL (75 micrograms/ml) for 4 hrs could significantly increase the adhesion of U937 to HUVEC (P < 0.01) and Ginkgo extract could suppress the adhesion in dose-dependent manner. The surface expression of VCAM-1, ICAM-1, P-selectin was not induced by MM-LDL, while recombination tumor necrosis factor-alpha 5.0 ng/ml, as a positive control, could do. CONCLUSION: Ginkgo extract afforded protection against HUVEC damage induced by MM-LDL and the adhesion of monocytes to endothelial cells induced by MM-LDL is not mediated by VCAM-1, ICAM-1 and P-selectin.

Cell Adhesion↗
PubMed1999

Computing minimum description length for robust linear regression model selection.

A minimum description length (MDL) and stochastic complexity approach for model selection in robust linear regression is studied in this paper. Computational aspects and implementation of this approach to practical problems are the focuses of the study. Particularly, we provide both algorithms and a package of S language programs for computing the stochastic complexity and proceeding with the associated model selection. A simulation study is then presented for illustration and comparing the MDL approach with the commonly used AIC and BIC methods. Finally, an application is given to a physiological study of triathlon athletes.

Algorithms↗
PubMed1999

[The role of apoptosis and Fas/FasL in lung tissue in patients with acute respiratory distress syndrome].

OBJECTIVE: To evaluate the effects of apoptosis and expression of apoptotic related genes on acute respiratory distress syndrome (ARDS). METHODS: Nine patients with ARDS and 5 non-ARDS patients were included. By using TUNEL, histopathology and immunocytochemistry techniques, apoptosis and Fas, FasL protein expression were studied in patients with ARDS in acute stage and in control subjects. RESULTS: Apoptosis ratio was significantly higher in lung tissues in the patients with ARDS than in those of control subjects, especially in alveolar epithelial cells and pulmonary vascular endothelial cells. Fas, FasL protein expression were up-regulated in lung tissues of patients with ARDS. There was a significant correlation between expression of Fas, FasL and ratio of apoptosis. CONCLUSIONS: During the acute stage of ARDS, increase of apoptosis ratio in alveolar epithelial cells and pulmonary vascular endothelial cells, and activation of Fas/FasL system may contribute to the pathogenesis of this syndrome.

Adult↗