Biomedical subjects

Lin Zhang

Publications and source records attributed to Lin Zhang.

At least 109 records · Page 6Linked to original sources

PubMed2006

[Inhibitory effect of blocking expression of human augmenter of liver regeneration (hALR) on proliferation of hepatocellular carcinoma cell line HepG2].

BACKGROUND & OBJECTIVE: Human augmenter of liver regeneration (hALR) is highly expressed in hepatocellular carcinoma (HCC), but rarely expressed in normal liver cells. ALR could stimulate the proliferation of HCC cell line in vitro, but has no effect on normal hepatocytes. This study was to investigate the inhibitory effect of blocking the expression of hALR on the proliferation of HCC cell line HepG2 using small interfering RNA (siRNA) targeting ALR and anti-ALR monoclonal antibody (McAb). METHODS: RNA interference (RNAi) plasmid pSIALR-A targeting hALR cDNA and control plasmid pSIALR-B were constructed and transfected into HepG2 cells, respectively. After transfection, the expression of green fluorescent protein was observed under a fluorescent microscope to calculate transfection efficiency, the protein level of hALR was measured by immunocytochemistry, meanwhile, the expression of hALR mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR). (3)H-TdR incorporation approach was performed to detect the proliferation of HepG2 cells after transfection and after neutralization with anti-hALR McAb. RESULTS: hALR was expressed in HepG2 cells. Plasmids pSIALR-A and pSIALR-B were successfully constructed. Both immunocytochemistry and RT-PCR showed that pSIALR-A inhibited the expression of hALR in HepG2 cells significantly by 83% as compared with pSIALR-B. pSIALR-A specifically inhibited the growth of HepG2 cells after transfection. (3)H-TdR incorporation of pSIALR-A/HepG2 cells was significantly lower than that of pSIALR-B/HepG2 cells (67 687+/-6 548 vs. 104 807+/-5 713, P<0.05). Anti-hALR McAb markedly inhibited the autonomous growth of HepG2 cells (P<0.05). CONCLUSIONS: hALR is highly expressed in HepG2 cells. The short interfering RNA targeting hALR gene could specifically suppress the expression of hALR, and subsequently inhibit the growth of HepG2 cells. Anti-hALR McAb could partially inhibit the autonomous growth of HepG2 cells.

Antibodies, Monoclonal↗

PubMed2006

Dopamine receptors oppositely regulate cocaine-induced transcription factor CREB activation.

OBJECTIVE: To study the role of dopamine receptors in the regulation of the activity of transcription factor cAMP response element-binding protein (CREB) after cocaine treatment. METHODS: By using dopamine receptor antagonists SCH23390 and nafadotride, the activation of CREB by D1 and D3 dopamine receptors after cocaine treatment and role of extracellular signal-regulated kinase (ERK) in cocaine-induced CREB activation were examined by Western blotting, which was also employed for determination of the effect of SCH23390 and nafadotride on CREB activation. RESULTS: D1 receptor antagonist could inhibit cocaine-induced CREB activation, while D3 receptor antagonist enhanced cocaine-induced CREB activation. Dopamine receptor antagonists SCH23390 and nafadotride did not induce CREB activation. SL327, a MEK inhibitor, inhibited cocaine-induced CREB activation. CONCLUSION: D1 and D3 dopamine receptors can oppositely regulate CREB activation after cocaine treatment and this regulation depends on ERK signaling pathway.

Animals↗

PubMed2006

[The calibration of instrument response function during passive FTIR measurement].

In order to obtain infrared spectral radiance distribution of some infrared sources, such as spectral radiant flux density, spectral radiant intensity, spectral radiance and spectral irradiance, the instrument response function under different conditions must be known. In the present paper, the calibration of instrument response function during passive FTIR measurement has been discussed. The experimental results illustrate that under different experimental conditions, the instrument response function varies not only with the temperature of the blackbody but also with the signal amplitude received by the infrared instrument. So, during passive FTIR measurement, the temperature and the emission signal amplitude of the source must be observed carefully in order to get satisfactory instrument response function.

English Abstract↗

PubMed2006

[Automated recognition of VOCs using artificial neural networks].

Quantitative analysis of FTIR spectra, which are seriously overlapped in the spectral bands, was studied by artificial neural networks. The optimum network was chosen by a new criterion, i. e. the degree of approximation. After the network was established, two kinds of spectra were resolved. It was demonstrated that accurate results could be obtained when two components were both included. In addition, the unknown spectrum could be identified and quantified. It was showed that the artificial neural network has excellent non-linear ability of solution. Meanwhile, the method provides an efficient approach to the identification and quantification of the unknown samples.

English Abstract↗

PubMed2006

[Remote passive detection of flame temperature of solid propellant adulterating nanoparticles].

The flame temperature of three kinds of solid propellants was measured by passive remote sensing FTIR with the resolution of 1 cm(-1). These three kinds of solid propellants are adulterate nano-scale metal oxide particles, adulterate normal metal oxide particles, and propellant without any adulterations. The main components of the solid propellant are nitrocellulose and nitroglycerin. The metallic oxides, including 6 nm CuO, 56 nm Fe2O3, 16 nm NiO, and correspondingly the normal particles, were adulterated into the solid propellants respectively. The flame temperature was calculated through the fine structure of the emission fundamental band of H2O at 2.75 microm. The results of the flame temperature of the solid propellants adulterating nano-scale CuO, Fe2O3 and NiO are 3089, 3193 and 3183 K, respectively. The temperatures of the three kinds of solid propellants were compared, and it was shown that there is no obvious difference in the flame temperature among the three kinds of solid propellants.

English Abstract↗

PubMed2006

[Multi-component analysis of FTIR spectra of non-linear system using polynomial partial least squares method].

A non-linear algorithm, polynomial PLS was applied to the simultaneous analysis of OP-FTIR spectra of a five-component system whose FTIR spectra were seriously overlapped. The results were compared with the one obtained from PLS. PPLS yielded good performance, especially for the prediction of benzene and chloroform. RMSEP (root mean squared error of prediction) of benzene and chloroform in PPLS model were 0.043 and 0.087 and the corresponding values in PLS were 0.402 and 0.842, respectively. Meanwhile, variance was accounted by PPLS with fewer latent variables, which indicates the simplicity and robustness of the model. The successful application of PPLS to non-linear system was meaningful for the use of remote sensing FTIR in air monitoring.

English Abstract↗

PubMed2006

[Effect of serum autoantibodies against the M2 muscarinic acetylcholine receptors from patients with heart failure on L-Type Ca2+ channel activity in guinea pig cardiac myocytes].

OBJECTIVE: To investigate the effect of serum autoantibodies against the human M(2) muscarinic acetylcholine receptors (M(2)-receptors, Abs) from patients with congestive heart failure on L-Type Ca(2+) channel activity in guinea pig cardiac myocytes. METHOD: Using whole cell patch-clamp technique, we quantitatively measured the ionic intensity and density of L-Type Ca(2+) channel (I(Ca-L)). RESULTS: The M(2)-receptors agonist (carbachol) could decrease the I(Ca-L) peak intensity and density stimulated by isoprenaline from (2111.65 +/- 203.13) pA and (18.83 +/- 1.14) pA/pF to (1230.87 +/- 208.14) pA (P < 0.01) and (10.72 +/- 1.06) pA/pF (P < 0.01). The serum Abs could also decrease I(Ca-L) peak intensity and density [from (1995.21 +/- 195.13) pA and (18.13 +/- 1.03) pA/pF to (636.42 +/- 110.07) pA (P < 0.01) and (5.54 +/- 0.81) pA/pF, P < 0.01]. The M(2)-receptors antagonist, atropine was able to block these effects of carbachol and Abs. CONCLUSIONS: The circulating serum autoantibodies against the M(2)-receptors has similar effect as M(2)-receptors agonist on decreasing the isoprenaline stimulated I(Ca-L) in guinea pig cardiac myocytes and possess negative inotropic effect. These results further suggest that serum autoantibodies against the human M(2) muscarinic acetylcholine receptors may participate in the pathophysiological processes in patients with heart failure.

Adult↗

PubMed2006

[A minisequencing technique for genotyping 12 Y-SNP and its genetic polymorphisms].

OBJECTIVE: The aim of the present study was to establish a rapid and robust assay used to simultaneously genotype SNPs by the single nucleotide primer extension (minisequencing) with the SNaPshot Kit and obtain the population genetic data in Chinese population in Sichuan. The analysis of single nucleotide polymorphisms (SNPs) is a promising application in forensic casework. METHODS: 12 Y-SNPs, which were SRY2627, SRY1532, M13, M20, SRY8299, Tat, M69, M9, 92R7, M17, M19 and M112, were multiple amplificated and the PCR products were pooled, Purified, and then used as templates for the minisequencing reaction with the commol/Lercially available SNaPshot Kit. Then the products of minisequencing reaction were detected by capillary elcetrophoresis. RESULTS: 78 genomic DNA individual samples from Sichuan, China and 5 semen stain samples from sexal criminal scene were analyzed and two haplotypes could be identified. CONCLUSION: A rapid method has been established to analyze the 12 Y-SNPs by multiplex PCR and minisequencing. It can be applied in forensic casework successfully.

Base Sequence↗

PubMed2006

[Establishment of a three-dimensional finite element model of mandible with dental implants for immediate loading].

PURPOSE: To establish a three-dimensional finite element model of mandible with dental implants for immediate loading, which will provide a basis for study of the biomechanical characteristics of the immediate loading implant-bone interface. METHODS: A female edentulous mandible was adopted for CT scanning, the scanned data were saved with the form of DICOM, and then input into compute. Universal Surgical Integration System which was developed by ourselves and ANSYS 10.0 were used to divide mesh and establish finite element model. Three dental implants simulating the real shape of ITI thread implant were embedded in the anterior region of the mandible, of which implant-bone interface was granted with situation of smooth friction simulating the case of immediate loading. RESULTS: The accurate finite element model of mandible with dental implants for immediate loading was established, which included 127811 tetrahedron elements with 182252 nodes. A single dental implant model comprised 13924 elements with 21420 nodes, the thread of it was continuous and smooth. CONCLUSION: The biomechanical similarity, the geometrical analogy and clinical indication of the model were quite good. The three-dimensional finite element model developed by this method can apply for precise analysis of the rule of biomechanics on the implant-bone interface for immediate loading.

Dental Implants↗

PubMed2006

[An epidemiological survey on the psychological stress status for students in 13 Chinese colleges].

OBJECTIVE: To explore the main sources causing stress among Chinese college students and its distribution. METHODS: A clustered random sampling method was conducted to perform the questionnaire on psychological stress among 2007 students selected from 13 universities. RESULTS: The main sources of psychological stress on college students regarding learning task, college environment, job-seeking, interpersonal relationship and emotional disorders. 49.3% of the population experienced mild level of psychological stress, 8.4% belonged to critical groups who experienced higher levels of stress,while 0.3% experienced severe level of stress. Sophomores and juniors were under more stressful situation than freshmen and senior students, while female students felt more stressful on learning and job-seeking than males. Male students felt more stressful caused by their families, health status, love affairs, social adaptation and frustration than females. Students from countryside were under more stress than those coming from urbans. Students from ordinary universities felt more stressed than those from famous universities and students from western areas were under more stress than those from the coastal areas. CONCLUSION: Stress had become a severe problem influencing the mental health development among college students. The problem needs to be addressed accordingly.

China↗

PubMed2006

[Model study on CO2 removal by photobioreactor].

The key point of study on CO2 removal by microalgae cultured in a photobioreactor is to improve CO2 removal capability. In this paper, a model of air-lift photobioreactor was developed by combination of conditions including the velocity of flow, the degree of mixing, the gas-liquid mass transfer and the rate of photosynthesis, and two corresponding simplified methods, such as time discretization and lumped parameters were put forward. Using a method of lumped parameters, the model for simulation of time course of DO, pH in the column air-lift photobioreactor and prediction of CO2, O2 concentrations in the outlet gas under different CO2 concentration in the aeration gas was thoroughly discussed. Experimental data were also used to verify the model which could potentially be applied to rational design of the photobioreactor, high-density culture of microalgae and efficient removal of CO2.

Bioreactors↗

PubMed2006

[Species identification by multiplex amplifying mtDNA-HV I, HV II and cytb regions].

OBJECTIVE: To evaluate the method for species identification by multiplex amplification of mtDNA-HV I, HV II and cytb regions. METHODS: The bloodstains or muscular tissues of human and 16 kinds of animals were collected. DNA were quantified after extraction. Three pairs of primers were mixed in the same reaction and the PCR amplification products were analyzed by PAGE and silver staining. RESULTS: The presence of three bands (278 bp, 358 bp, 425 bp) indicated the samples were from human, while only one band indicated nonhuman origin. The position of the animal's only band is different from the band (358 bp) of human. CONCLUSION: The method of species identification by multiplex amplifying mtDNA-HV I, HV II and cytb regions is simple and sensitive. It is of use for forensic identification.

Animals↗

PubMed2006

[Nitroglycerin tolerance aggravates arterial ischemia/reperfusion injury by increasing nitrotyrosine and ONOO- production].

OBJECTIVE: To investigate the influence of nitroglycerin tolerance (NT) on arterial ischemia (90 min) and reperfusion (120 min). METHODS: Male Sprague-Dawley rats were infused with nitroglycerin (GTN) or saline for 12 h and ascending aorta was rapidly isolated. The isolated aorta was subjected to one of the following treatments: stimulative ischemia/reperfusion, stimulative ischemia/reperfusion (I/R) plus glutathione (GSH, 0.1 mmol/L) during reperfusion, or control solution (Kreb's solution for 3.5 h). RESULTS: Compared with I/R group, contractile function, vasorelaxation responses to Ach, NO production were significantly decreased and CK, LDH activity as well as nitrotyrosine formation in reperfusion solution were significantly increased in I/R + NT group and these effects could be prevented with addition of GSH in I/R + NT aortas. CONCLUSIONS: Our results demonstrated that NT could aggravate arterial I/R injury by increasing the production of ONOO- and GSH may play a cardioprotective role against NT-induced myocardial injury by attenuating the formation of ONOO-.

Animals↗

PubMed2006

[Calibration transfer used for the interpretation of RS-FTIR spectrum].

A technique of analysis for RS-FTIR (Remote Sensing Fourier Transform Infrared) spectrum was built based on the principle of calibration transfer. A system of four-component gas mixtures, whose FTIR spectra were overlapped seriously, was determined as the object in the present research. Its FTIR data from EPA and field measurement were used to set up calibration and prediction models, respectively. With OSC (orthogonal signal correction), the model built with data of EPA predicted values of field measurement. The RMSEP values of acetone, methanol, benzene and chloroform were 0.0085, 0.0180, 0.0640 and 0.0028, respectively, while without OSC correction the corresponding values were 0.0856, 0.0479, 1.0653 and 0.0142, respectively. With optimization, the Kennard-Stone method was used for subset selection, and the iteration in the process of OSC was carried out 3 times, yielding the best performance. The result indicates that this technique can overcome the limitation of background and calibration model, which restricts the application of RS-FTIR in air monitoring.

English Abstract↗

PubMed2006

Protein expression of human neuron-specific enolase and its antiserum preparation.

OBJECTIVE: To clone and express human neuron-specific enolase (HuNSE) protein and prepare NSE-specific antibody for prion disease diagnosis. METHODS: HuNSE gene was amplified by RT-PCR and subcloned into a HIS-tagged expression vector pQE30 after sequence verification. HIS-NSE fusion protein expression was obtained in E. coli M15 after IPTG induction followed by purification of the fusion protein by Ni-NTA affinity chromatography. Two male rabbits were immunized for 4 times with the purified protein, and the antiserum against NSE protein was collected and evaluated by enzyme-linked immunosorbent assay (ELISA), Western blotting and immunohistochemistry. RESULTS: SDS-PAGE assay yielded an approximately 22 kD HIS-NSE fusion protein. The prepared antiserum could recognize both recombinant NSE protein and native NSE protein extracted from the brain tissues of different mammalian species as shown by Western blotting and immunohistochemistry. CONCLUSION: High expression of HuNSE is obtained in E. coli and the prepared antiserum against HuNSE can be used potentially for diagnosis of prion-associated diseases and other nervous degeneration diseases.

Animals↗

PubMed2006

[Comparison of endoscopic ultrasonography with computer-assisted tomography in the determination of preoperative stage and resectability of pancreatic and ampullary cancers].

OBJECTIVE: To study and compare the accuracy and sensitivity of endoscopic ultrasonography (EUS) and CT scaning in determination of preoperative stage and vascular invasion by pancreatic and ampullary cancers. METHODS: Fourty-two pancreatic cancer patients and 18 ampullary cancer patients were studied. With patients prepared according to conventional endoscopy, Olympus EUM-30 scope 1 set with a side view and 360 degrees rotate and switchable scanning probe [ultrasound frequency (7.5/12 MHz)], was introduced to the descending duodenum through the esophagus. Gas within the duodenum and stomach was aspirated. Then, in order to to facilitate ultrasound transmission, 200 ml deaerated water was injected into the duodenum and 500 ml into the stomach to distend it. The structures of each part of pancreatic head and ampullary together with surrounding vessels were scanned. Then, the scope was withdrawn to the gastric antrum, body and fundus gradually, while the pancreatic body and tail were scanned. RESULTS: Between Apr. 1996 to May 2004, a total of 42 pancreatic cancer patients and 18 ampullary cancer patients were examined by EUS. Meanwhile, all these 58 patients received preoperative CT scaning. The results of stage and vascular invasion determined by EUS in this series were as following; pancreatic cancer group (n = 42): accuracy in T2-4 stage was 100.0% (5/5), 75.0% (9/12) and 48.0% (12/25), respectively; ampullary cancer group (n = 18): T1-4 stage was 75.0% (3/4), 66.7% (2/3), 75.0% (6/8) and 33.3% (1/3), respectively; the accuracy in N stage: P-group: 80.0% in N1 (4/5), 90.0% in N0 (9/10); A-group: 50.0% in N1 (3/6), 91.0% in N0 (10/11). The sensitivity, specificity of vascular invasion, resectability and unresectablilty determined by EUS and CT as compared with surgical findings during operation was 52.9% (9/17), 93.1% (27/29), 77.1% (27/35) and 81.8% (9/11) for EUS (n = 60), respectively; and 11.8% (2/17), 92.6% (25/27), 62.5% (25/40) and 50.0% (2/4) for CT (n = 58), respectively. CONCLUSION: Endoscopic ultrosonography being one of the best image examinations to determine the stage and vascular invasion for pancreatic and ampullary cancer paitients is able to detect small pancreatic or ampullary cancer less than 2.0 cm in diameter due to its high resolution; but can not detect the secondary multiple distal metastases such as spread into the liver, peritonium or hepatoduodenal ligament, etc. due to its ultrasound depth limitation.

Ampulla of Vater↗

PubMed2006

[Allele frequencies and species specificity of five short tandem repeat loci of Chinese Han population in Chengdu].

OBJECTIVE: To obtain the data in polymorphism distribution of the five short tandem repeat (STR) loci: D18S979, D11S2014, D18S548, D1S1667 and GATA164F07 of Chinese Han population in Chengdu, and to evaluate their usefulness in the field of species specificity in forensic science. METHODS: PCR, polyacrylamide gel electrophoresis (PAGE) and silver staining techniques were used to analyze the DNA samples from 100 unrelated individuals of Chinese Han ethnic group in Chengdu. Twelve different animals: monkey, pig, dog, bull, goat, chicken, duck, eel, mudfish, rabbit, guinea pig and mouse were selected as controls in this study for evaluating the species specificity of the five STR loci. RESULTS: Six alleles and twelve genotypes were observed in D18S979. Five alleles and eleven genotypes were observed in D11S2014. Five alleles and thirteen genotypes were observed in D18S548. Seven alleles and nineteen genotypes were observed in D1S1667. Six alleles and fourteen genotypes were observed in GATA164F07. The genotype distributions of the five loci were analyzed by some related software and no deviation from the Hardy-Weinberg equilibrium was observed. Evaluated by way of using different animals as controls, monkey had amplification products at the extra-typing field of D18S979, D11S2014 and D1S1667. Bull, dog and eel had amplification product at typing field of D18S979, and pig, duck, mouse and rabbit had weak product. Bull had weak product at the typing field of D18S548. Dog, goat and eel had product at the typing field of D1S1667. Dog had weak product at the typing field of GATA164F07. Mudfish, chicken and guinea pig had no amplification product at the five loci. CONCLUSION: These data indicate that D18S979, D18S548, D1S1667 and GATA164F07 are highly polymorphic and D11S2014, D18S548 and GATA164F07 can play a key role in species identification.

Animals↗

PubMed2006

[Advanced development of remote sensing FTIR in air environment monitoring].

Remote sensing FTIR(RS-FTIR) is one of the most important technologies in atmospheric pollutant monitoring. It has several prevailing advantages: (1) high resolution and high selectivity; (2) it requiring no sampling and no sample preprocessing; (3) capability of detecting several compounds simultaneously; (4) real time, long distance, and automatic monitoring. So it is extraordinarily appropriate for the quantitative and qualitative determination, and remote, real time, dynamic monitoring of air contaminant, especially the toxic volatile organic compounds (VOCs). The present paper reviews the research progress in remote sensing FTIR for air monitoring made by the Laboratory of Advanced Spectroscopy in recent years, including chemometrics, computed tomography, FTIR spectra interpretation, spatial distribution of air pollutant concentration and passive remote monitoring, etc. These research findings show that the rapid development and application of remote sensing FTIR accelerated the temporal and spatial extension of analytical chemistry, and it will by all means have wide prospects in atmospheric environmental monitoring.

English Abstract↗