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Biomedical subjects

Jing Li

Publications and source records attributed to Jing Li.

At least 325 records · Page 18Linked to original sources
PubMed2004

The in vitro and in vivo proliferative capacity of serum-free cultivated human conjunctival epithelial cells.

PURPOSE: To investigate the in vitro and in vivo proliferative capacity of human conjunctival epithelial cells cultured in serum-free media, and to compare this with current methods that utilize serum-containing media and 3T3 feeder layers. METHODS: Human conjunctival epithelial cells were cultivated in serum-free media alone, serum-free media with a 3T3 feeder layer, and serum-containing media with a 3T3 feeder layer. The areas of outgrowth, colony-forming efficiencies and number of population doublings were compared. The in vivo proliferative potential was assessed by analyzing the number of cells generated by the implantation of cultured cells into athymic mice. Cultured cells were evaluated for the expression of cytokeratins K3, K4, K12, K19, as well as the gel-forming goblet cell mucin, MUC5AC. RESULTS: Cells cultivated in serum-free media, serum-free media and feeder cells, and serum-containing media and feeder cells achieved colony-forming efficiencies of 14.5 +/- 4.1%, 10.1 +/- 3.1%, and 20.4 +/- 6.7%, respectively, and number of population doublings of 24.8 +/- 4.3, 14.8 +/- 3.6, and 30.0 +/- 5.0, respectively. Nine-day old athymic mice conjunctival cysts derived from serum-free cultures comprised 1.29 x 10(6) +/- 0.46 x 10(6) cells, while cysts derived from serum-containing cultures comprised 1.30 x 10(6) +/- 0.53 x 10(6) cells. The degree of epithelial stratification was similar in both conditions. Serum-free cultivated conjunctival cells retained their in vivo characteristics and expressed K4, K19 and MUC5AC. The presence of MUC5AC mRNA in these cells was confirmed by RT-PCR. CONCLUSIONS: Conjunctival epithelial cells propagated in serum-free media demonstrated a similar in vivo proliferative capability, as compared to serum-containing media with 3T3 feeder cells. This has important clinical implications, as the serum-free ex vivo expansion of cells for clinical transplantation overcomes the problems associated with the use of animal serum and cells.

3T3 Cells↗
PubMed2004

Differential damage and recovery of human mesenchymal stem cells after exposure to chemotherapeutic agents.

Mesenchymal stem cells (MSCs) are an important cellular component of the bone marrow microenvironment for supporting haemopoiesis. However, their response to high-dose chemotherapy remains unknown. We assessed the acute direct effects of individual chemotherapeutic agents on human MSCs (hMSCs). Using an in vitro culture system, the chemosensitivity of hMSCs was determined by XTT (2,3-bis(2-methoxy-4-nitro-5-sulphophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide) assay in comparison with that of NB-4 cells, a leukaemic cell line, and normal peripheral blood mononuclear cells. The recovery of cell numbers following exposure to chemotherapeutic agents and chemotherapy-induced apoptosis of hMSCs were evaluated. Human MSCs were resistant to chemotherapeutic agents commonly used in bone marrow transplantation (BMT) (i.e. busulphan, cyclophosphamide and methotrexate). However, they were relatively sensitive to a panel of cytotoxic agents, such as paclitaxel, vincristine, etoposide and cytarabine. Furthermore, different recovery patterns were noted. There was sustained suppression in hMSCs following 3 d exposure to paclitaxel, cytarabine and etoposide. In contrast, significant recovery was seen in hMSCs treated with dexamethasone and vincristine respectively. Human MSCs have different patterns of response to a panel of chemotherapeutic agents commonly used in BMT or cancer therapy. Understanding this variation is important in optimizing conditioning regimens for BMT.

Antineoplastic Agents↗
PubMed2004

Analysis of serum cytokines in patients with severe acute respiratory syndrome.

Severe acute respiratory syndrome (SARS) is an acute infectious disease of the respiratory system. Although a novel coronavirus has been identified as the causative agent of SARS, the pathogenic mechanisms of SARS are not understood. In this study, sera were collected from healthy donors, patients with SARS, patients with severe SARS, and patients with SARS in convalescence. The serum concentrations of interleukin-1 (IL-1), IL-4, IL-6, IL-8, IL-10, tumor growth factor beta (TGF-beta), tumor necrosis factor alpha (TNF-alpha), and gamma interferon (IFN-gamma) were measured by enzyme-linked immunosorbent assays (ELISA). The concentrations of IL-1 and TNF-alpha were not significantly different in different groups. The IL-6 concentration was increased in SARS patients and was significantly elevated in severe SARS patients, but the IL-6 concentrations were similar in convalescent patients and control subjects, suggesting that there was a positive relationship between the serum IL-6 concentration and SARS severity. The concentrations of IL-8 and TGF-beta were decreased in SARS patients and significantly reduced in severe SARS patients, but they were comparable in convalescent SARS patients and control subjects, suggesting that there was a negative relationship between the IL-8 and TGF-beta concentrations and SARS severity. The concentrations of IFN-gamma, IL-4, and IL-10 showed significant changes only in convalescent SARS patients. The IFN-gamma and IL-4 levels were decreased, while the levels of IL-10 were increased, and the differences between convalescent SARS patients and other patient groups were statistically significant. These results suggest that there are different immunoregulatory events during and after SARS and may contribute to our understanding of the pathogenesis of this syndrome.

Adolescent↗
PubMed2004

Assessment of the therapeutic activity of a combination of almitrine and raubasine on functional rehabilitation following ischaemic stroke.

BACKGROUND AND OBJECTIVES: Stroke is a major cause of disability. Certain experimental studies have suggested that a combination of almitrine + raubasine (Duxil) increases the supply of oxygen to cerebral tissues and may be beneficial in post-stroke rehabilitation. This multicentre clinical study was carried out in order to assess the efficacy of this combination on poststroke rehabilitation. METHODS: The trial was a randomised, double-blind, placebo-controlled study. Patients that had experienced an ischaemic cerebrovascular accident (confirmed by CT scan) were included 4-6 weeks after the acute onset and received randomised treatment of either almitrine + raubasine or placebo 2 tablets daily for 3 months. Before treatment, there was a 2-week washout period for stopping all other drugs, except for antihypertensive and antidiabetic drugs. We assessed the patients by Barthel Index (BI), Neurological Functional Deficit Scores (NFDS), and Hasagawa Dementia Scales (HDS) each month after treatment. RESULTS: A total of 83 patients were entered into the study and data were available for 74. Of these, 38 patients received almitrine + raubasine and 36 received placebo. The baseline characteristics were comparable between both groups. Almitrine + raubasine was significantly more effective than placebo at increasing BI at 1, 2 or 3 months (14.6 +/- 13.8 versus 3.3 +/- 13.2, p = 0.01; 19.3 +/- 13.6 versus 8.8 +/- 14.0, p = 0.02; 22.6 +/- 14.7 versus 10.7 +/- 17.0, p = 0.02 respectively) and reducing NFDS at 1 month (3.6 +/- 3.2 versus 1.9 +/- 3.5, p = 0.034) after treatment. More almitrine + raubasine-treated patients' NFDS had improved compared with placebo-treated patients at 2 and 3 months (97 versus 78%, p = 0.013; 100 versus 86%, p = 0.023 respectively). Compared with pretreatment, there was a strong tendency towards an improvement of HDS with almitrine + raubasine. The number of adverse events reported was low for the almitrine + raubasine-treated group and the placebo group and all events were mild, of short duration and resolved without treatment. Almitrine + raubasine had no clinically significant effect on blood pressure, heart rate or other laboratory tests. CONCLUSION: The results indicate that almitrine + raubasine can accelerate neurological function recovery after stroke to some degree and is well tolerated.

Aged↗
PubMed2004

Acidic oligosaccharide sugar chain, a marine-derived acidic oligosaccharide, inhibits the cytotoxicity and aggregation of amyloid beta protein.

In this paper, we investigated interactions of the acidic oligosaccharide sugar chain (AOSC), derived from brown algae Echlonia kurome OKAM, with amyloid beta protein (Abeta). We observed that AOSC inhibited the toxicity induced by Abeta in both primarily cortical cells and the SH-SY5Y cell line. We also observed that AOSC inhibited the apoptosis induced by Abeta in SH-SY5Y by reducing the elevated level of intracellular calcium concentration ([Ca(2+)](i)) and suppressing the generation of reactive oxygen species. Surface plasmon resonance analysis demonstrated that AOSC had affinity for both freshly-dissolved Abeta and 48-h incubated Abeta. Furthermore, AOSC blocked the fibril formation of Abeta, which may be responsible for its anti-cytotoxic effects. Thus, our results indicate that AOSC might be a potentially therapeutic compound for Alzheimer's disease.

Amyloid beta-Peptides↗
PubMed2004

Transfer in SDS of biotinylated proteins from acrylamide gels to an avidin-coated membrane filter.

Avidin was covalently linked to aldehyde-derivatized polyethersulfone membrane filters. These filters were used in Western blot analysis of proteins reacted with biotinylation reagents and electrophoresed in sodium dodecyl sulfate (SDS) on polyacrylamide gels. Electrophoretic transfer from the gels to these filters was in 0.1% SDS, in which the covalently bound avidin retained its biotin-binding capacity. We compared Western blots on avidin-coated membrane filters of biotinylated and nonbiotinylated forms of mouse immunoglobulin G (IgG), mouse IgG heavy chain, muscle-type acetylcholine receptor alpha subunit, and fused alpha and beta subunits of receptor. Biotinylated proteins were captured with high specificity compared to their nonbiotinylated counterparts and sensitively detected on the avidin-coated membranes.

Acrylamides↗
PubMed2004

[Protective effects of fructose-1,6-diphosphate on brain damage caused by febrile seizures in rats].

OBJECTIVE: Febrile seizure (FS) is a pediatric emergency. The reiterative attacks of FS may result in brain damage to various extents. Fructose-1,6-diphosphate, serving as a cellular energy substance, has been applied to clinical practice for many years and has shown its importance in adjuvant treatment of diseases with myocardial damage. This study aimed to explore the potentiality of protecting rats' brain damage caused by febrile seizure with fructose-1,6-diphosphate (FDP). METHODS: Thirty 21-day-old male Sprague-Dawley (SD) rats were randomly divided into febrile seizure group (FS), sodium chloride solution (NS) control group and FDP intervention group (FD). Febrile seizure was induced by hyperthermal bath at 45 degrees C in the present study. No intervention treatment was given to rats in FS group before febrile seizure. Thirty minutes before febrile seizures, rats in FD group were given peritoneal injection of FDP at a dose of 25 mg per 100 g of body weight, whereas the same volume of 0.9% sodium chloride solution was injected into peritoneum of rats in NS group. Manifestations of seizure and differences in seizure latency, duration of seizure and seizure severity were observed in all the 3 groups. Samples of rat brain were prepared for electron microscopy in order to understand the characteristics of the ultrastructural changes in mitochondria, interspace of neuronal synapses and neurons of hippocampal region CA(1). RESULTS: Data collected from this study indicated that peritoneal injection of FDP at 25 mg per 100 grams of body weight 30 minutes before febrile seizures could result in improvement of the clinical manifestation of the rats caused by febrile seizures. Specifically speaking, the seizure latency was prolonged, the duration of seizures was shortened and severity of seizure was reduced. Analysis of variance and q-test on the data collected from the 3 groups revealed that there were significant differences between FD group and the other two groups (P < 0.05), yet no significant difference was found between FS group and NS group (P > 0.05). Electron microscopic observations on brain specimens revealed that FDP could relieve mitochondrial degeneration and edema. FDP could also reduce neuronal degeneration and necrosis in hippocampal region CA(1) (the percentages of neuronal degeneration and necrosis in the 3 groups were respectively 13% for FD group, 28% for FS group and 30% for NS group). There was a significant difference between FD group and the other two groups (P < 0.05), FDP treatment could prevent interspace of neuronal synapses from enlarging (the mean interspace was 6.47 +/- 0.37 micro m for FD group, 7.60 +/- 0.36 micro m for FS group and 7.53 +/- 0.40 micro m for NS group. The difference between FD group and the other two groups was significant (P < 0.01). CONCLUSION: FDP could lead to prolonged seizure latency, shorter duration of seizures and mitigation of seizures severity. FDP could also reduce neuronal degeneration and necrosis and prevent the interspace of neuronal synapses from enlarging in hippocampal region CA(1). The present study suggests that FDP can protect brain of rat from damages caused by febrile seizures.

Animals↗
PubMed2004

Assessment of left ventricular function in healthy subjects by pusled wave Doppler tissue imaging.

OBJECTIVE: To examine the clinical application of pulsed Doppler tissue imaging (DTI) for regional left ventricular function assessment in normal subjects. METHODS: We examined 50 healthy subjects (range 12-42 years, mean age 28.3 +/- 6.9 years) using pulsed Doppler tissue imaging to characterize the diastolic and systolic velocity profiles of mitral annulus. Recordings were made along the long axis in the apical 4-chamber, 2-chamber, and long apical views of 6 sites (posterior-septum, lateral, anterior, inferior, anterior-septum, posterior) at the mitral annulus. Myocardial velocities were determined with use of variance F statistical analysis. Correlation analysis was employed to test the relationship between age and mitral annular velocities. RESULTS: Both early diastolic and systolic velocities at the septum were lower than other sites. There were no differences in mitral annulus late diastolic velocities. Mean early diastolic and systolic velocities was negatively correlated with age. CONCLUSIONS: Doppler tissue imaging can directly reflect regional left ventricular function.

Adolescent↗
PubMed2004

[Diagnosis of childhood narcolepsy and significance of HLA in its diagnosis].

OBJECTIVE: Narcolepsy is a lifelong sleep disorder characterized by excessive daytime sleepiness, and features of rapid eye movement (REM) sleep, such as cataplexy, sleep paralysis and hypnagogic hallucinations. The present study aimed to investigate the diagnostic basis of childhood narcolepsy and possible role of HLA Class II alleles in the onset of this disease. METHODS: The clinical data of 40 narcoleptic children were analyzed. All patients received Multiple Sleep Latency Test (MSLT) and they were analyzed in combination with clinical features. Polymerase chain reaction/sequence specific primers (PCR/SSP) methods were used to detect the HLA-DRB1 and DQB1 alleles. RESULTS: Narcolepsy was diagnosed in 40 children. The age range was 3 to 14 years (mean 8.5 +/- 2.5 years), 29 were male and 11 female. Their mean course of disease was 6.5 months, 14 patients (30%) were less than 3 months old, 21 patients (52%) were less than 6 months old. All the patients had excessive daytime sleepiness, cataplexy appeared in 37 cases, hypnagogic hallucination in 22 and sleep paralysis in 6. Mean sleep latency on MSLT was less than 5 min, the average number of sleep-onset rapid eye movement (SOREM) was 4.33 +/- 0.26 episodes (2-5 episodes), the latency of SOREM episodes were 4.0 +/- 1.8 min (0.25-4.9 min). Thirty-five patients were DRB1 1501 and DQB1 0602 positive (Pc < 0.01), 2 were DRB1 1502 and DQB1 0601 positive, while 3 were DRB1 15 and DQB1 6 negative. CONCLUSIONS: Some pediatric patients with narcolepsy were different from adult patients in that the pediatric cases had a sudden onset and shorter disease course. Diagnosis of this disease was based on the clinical manifestations, MSLT and absence of any medical or psychiatric disorder that could account for the symptoms. The authors demonstrated that DRB1 1501 and DQB1 0602 were susceptibility genes for narcolepsy and those who were DRB1 15 negative could not be excluded.

Adolescent↗
PubMed2004

Association between Nm23-H1 gene expression and metastasis of ovarian carcinoma.

BACKGROUND & OBJECTIVE: Metastasis is the leading cause of treatment failure and death of ovarian cancer. However, The molecular mechanisms associated with acquisition of metastatic ability in ovarian cancer are poorly understood. This study aimed at selecting the ovarian carcinoma cell lines with high frequency metastasis and studing the association between nm23-H1 gene expression in the model of ovarian carcinoma cells so as to provide the evidence for systematical experimental studying and clinical practice. METHODS: Each ovarian cancer cell line was transplanted subcutaneously into the flank of nude mice, and the metastatic behavior was evaluated by counting the number of lung tumor foci at different time. The metastatic tumors were cultured in vitro, then established substrain and transplanted subcutaneously three times. The mRNA and protein level of nm23 in 8 human ovarian cancer cell lines were examined. RESULTS: Four cell lines have high frequency metastatic potentiality. The subpopulation of cells with high frequency metastasis could be screened by injection several times. The expression of nm23 mRNA and protein in human ovarian cancer cells is inversely related to metastatic behavior in experimental animals (r=0.96, P=0.0001). CONCLUSION: The difference of metastatic potential, which was determined by genetic and molecular levels, was significant among different type of cell lines and subtypes. The expression of nm23 mRNA and protein in human ovarian carcinomas were correlated closely with the reduced metastatic behavior in experimental animals and may serve as a sensitive prognostic indicator of ovarian cancer.

Animals↗
PubMed2004

[The cytokine secretion of peripheral blood mononucleocytes from patients infected with HCV].

AIM: To detect the levels of cytokines secreted by PBMC from patients infected with HCV after culture for 72 hours in-vitro, so as to reflect the immune state of the HCV-infected patients. METHODS: The levels of cytokines in the culture supernatant of PBMCs were detected by ELISA. RESULTS: (1)Compared with the cytokine level of normal control, the levels of IFN-gamma, TNF-alpha, and IL-10 of HCV patients notably increased while IL-2, IL-4, and IL-12 were not detected in the culture supernatant of PBMCs from both normal control and HCV patients after culture for 72 hours. (2)There was no statistic difference in secretion of cytokines among the patients with mild, and moderate chronic hepatitis, and compensated or uncompensated cirrhosis. CONCLUSION: (1)PMBCs from the HCV-infected patients tend to secret Th2 type cytokines. (2)Lack of the IL-2 secretion from PBMCs of HCV patients may account for the immune escape of HCV.

Adolescent↗
PubMed2004

Protective effect of a bacterial extract against acute exacerbation in patients with chronic bronchitis accompanied by chronic obstructive pulmonary disease.

BACKGROUND: Immunostimulating agents made from bacterial extracts represent a class of medications that contains antigens derived from several bacterial strains and their potential ability to prevent bacterial infections results from the stimulation of the nonspecific component of the immune system. The present study investigated the effect of the oral immunostimulant Broncho-Vaxom, which includes material from eight different species of bacteria that are frequently present in the lower respiratory tract, on the frequency and severity of acute exacerbation in patients with chronic bronchitis accompanied by chronic obstructive pulmonary disease (COPD). METHODS: Ninety patients with chronic bronchitis complicated with COPD were randomly divided into groups A and B. Forty-nine subjects in group A received oral capsules containing 7 mg Broncho-Vaxom, while 41 patients in group B received similar placebo capsules. Both groups took one capsule daily for the first 10 days of each month for 3 consecutive months. The frequency of acute exacerbation, symptom scores, and lung function were recorded for the following one year period. RESULTS: There was a significant decrease in the incidence, duration, and severity of acute exacerbation, as well as a reduction in the course of antibiotics administered and in the dosage of bronchodilator and mucolytic agent in group A, as compared to group B (P < 0.05, respectively). Symptom scores for cough, sputum, dyspnea, as well as symptoms observed upon auscultation of the chest also improved significantly in group A as compared to group B (P < 0.05, respectively). The bacterial clearance rate in sputum cultures from patients who received no antibiotics for the first 3 months was also significantly higher in group A compared to group B (P < 0.01). CONCLUSIONS: Orally administered Broncho-Vaxom is associated with a decrease in the incidence of acute exacerbation and a decrease in the need for antibiotics and symptomatic relief medications in patients with chronic bronchitis accompanied by COPD. Broncho-Vaxom is also associated with a decrease in symptom scores. Without causing any apparent adverse effects, this drug may also help to eradicate pathogenic bacteria in the airways.

Adjuvants, Immunologic↗
PubMed2004

[Response of Dolichomitriopsis diversiformis photosynthesis rate to light, air temperature and plant water content].

The net photosynthetic rate (Pn) of Dolichomitriopsis diversiformis(Mitt.) was measured under controlled air temperature (Ta), plant water content (PWC) and irradiance (Photosynthetically Active Radiation, PAR) in laboratory. The results showed that Pn was closely related to PAR, Ta and PWC. The response curve of Pn to PAR was a right angle hyperbola, and the parameters were affected by Ta and PWC. The Pn reduction was great when PWC was low and Ta was high, or when PWC was high and Ta was low. The peak Pn (Pmax) was observed underweak light (PAR < 200 mumol.s-1.m-2) and relatively low (50%-80%) PWC. Under higher Ta, Pmax was higher, but decreased when Ta was higher than 25 degrees C. The PWC range within which Pmax occurred increased in accordance with the increase of PAR. When PAR was lower than 200 mumol.s-1.m-2, the Ta range within which Pmax occurred was relatively high (20-25 degrees C), and Pmax increased with the increase of PWC. When PWC was higher than 80%, Pmax decreased with the increase of PWC. The Ta range within which Pmax occurred decreased in accordance with the increase of PAR. Under moderate light (230 < PAR < 270 mumol.s-1.m-2), the sensitivity of Pn response to Ta and PWC was higher than that under higher or lower light. The Pn response to Ta and PWC was saddle-like, and its parameters were altered according to the variation in PAR.

Bryophyta↗
PubMed2004

[Function of Tra2beta1 proteins in the splicing of neural-specific genes].

The in vitro studies have shown that Tra2beta1 proteins are important regulators in the alternative pre-mRNA splicing in mammalians. To date, the knowledge regarding the in vivo function of Tra2beta1 proteins, especially the function in regulating the splicing of neural-specific genes and the cell-type specificity of the functions is very limited. In the present study, the cell-type specific splicing of two neural-specific genes (GluR-B and SMN2), and the function of Tra2beta1 proteins in regulation of the splicing were studied in two types of cells (COS-1 and PFSK-1) using in vivo splicing models. The results showed that the splicing of GluR-B and SMN2 minigenes is cell-type specific, while Tra2beta1 proteins regulate the splicing of the minigenes in both cell lines in a similar pattern. It indicates that the Tra2beta1-regulated splicing of GluR-B and SMN2 minigenes regulated by Tra2beta1 is not cell-type specific.

Alternative Splicing↗
PubMed2004

[Increased atria expression of receptor activity-modifying proteins in heart failure patients].

OBJECTIVE: Receptor activity-modifying proteins (RAMPs) determine the ligand specificity of the calcitonin receptor-like receptor (CRLR); co-expression of RAMP1 and CRLR results in a calcitonin gene related peptide (CGRP) receptor, whereas the association of RAMP2 or RAMP3 with CRLR gives an adrenomedullin(ADM) receptor. As CGRP and ADM may play a beneficial role in heart failure, this study aimed at the question whether RAMPs mRNAs are changed in heart failure. METHODS: Semi-quantitative reverse transcription-PCR (RT-PCR) was used to detect and quantify the mRNAs of RAMP1 and RAMP3 in the atria of heart failing patients. RESULTS: It was found that the expressions of RAMP1, RAMP2 and RAMP3 mRNAs increased with the worsening of heart function, but the expressions of RAMP1 and RAMP2 mRNA decreased at level IV of heart failure. CONCLUSION: The above results demonstrated in the atria of heart failure patients an up-regulation of CGRP receptor by an increase of RAMP1 in association with CRLR and an up-regulation of ADM receptor by an increase of RAMP2 expression in association with CRLR, thus suggesting that CGRP and ADM receptors be playing a functional role in compensating the chronic heart failure in human.

Adult↗
PubMed2004

[Construction and expression of DNA-binding domain plasmid with hepatitis B virus e antigen in yeast double hybrid system].

BACKGROUND: Using hepatitis B virus e antigen (HBeAg) gene to construct the DNA-binding domain vector, which can express HBeAg in yeast cell, and can be used in yeast double hybrid as "bait plasmid" to look for the gene from the cDNA library, which expresses the protein that can interact with HBeAg. METHODS: PCR was performed to amplify the HBeAg gene from a sera of hepatitis B patient. The product of the amplification was inserted into T-vector and was verified by sequencing. Then it was inserted into the "bait" plasmid pGBKT7 after the digestion with the restricted endonuclease of EcoR I and Sal I. The plasmid was transformed into the yeast cell. PCR was used to verify whether the plasmid was transformed into yeast. The HBeAg protein expressed in the cell was confirmed by Western blot. Using nutrition selection assay to verify the constructed plasmid alone could not activate the reporter gene in the yeast cell. RESULTS: Sequenced and digested by two endonucleases, the recombined vectors pGBKT7-eAg produced anticipated fragment. PCR verified that there was HBeAg fragment in the yeast. Having assayed by Western blotting, it was shown that the yeast cell transformed with pGBKT7-eAg vector had positive signal which could not be seen in the control. Tested by the nutrition selection assay, the recombined vectors pGBKT7-eAg could not activate LacZ reporter gene in the yeast. CONCLUSION: DNA-binding domain plasmid was successfully constructed and could express HBeAg proteins in the yeast cell but could not activate transcription of LacZ reporter gene alone. The recombined plasmid can be used in yeast double hybrid.

Genetic Vectors↗
PubMed2004

[Study on interaction of Radix Paeoniae 801 and endothelin-1 by using a piezoelectric quartz crystal biosensor].

OBJECTIVE: To explore the possible target and molecular mechanism of Radix Paeoniae 801 (RP801), an effective ingredient extracted from Radix Paeoniae, the Chinese herbal medicine for activating blood circulation to remove blood stasis, using experimental in vitro method by directly detecting the interaction between RP801 and endothelin-1 (ET-1). METHODS: Piezoelectric quartz crystal biosensor, namely, the quartz crystal microbalance (QCM) was used to detect the specific combining between RP801 and ET-1 by binding avidin to the pre-activated Au surface of electrode of QCM, followed by immobilizing biotinylated ET-1 to it, and adding RP801, then the binding curve was recorded. PBS washing was applied at the end of every steps of combining reaction for dissociate the non-specific absorption. RESULTS: Specific combining of RP801 and ET-1 was found. CONCLUSION: ET-1 could possibly be one of the acting targets of RP801 in the body, that is, RP801 could combine with ET-1 to impede the binding of ET-1 with its receptor, so as to counteract the action of ET-1, dilate blood vessels and inhibit platelet aggregation.

Biosensing Techniques↗