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Biomedical subjects

Bin Zhou

Publications and source records attributed to Bin Zhou.

At least 37 records · Page 2Linked to original sources

A cyclic peptide-polymer probe for the detection of Clostridium botulinum neurotoxin serotype A.

A Botulinum neurotoxin serotype A (BoNT/A) ELISA detection system was developed based upon an 11-mer cyclic peptide, termed C11-019, that was identified through peptide phage display technology. The assay employs a sandwich format using the C11-019 cyclic peptide attached to a PEMA (poly(ethylene maleic anhydride)) matrix as the capture phase and anti-BoNT/A polyclonal antibodies as the detection phase. Results reported demonstrate that the C11-019 peptide-polymer can specifically bind to BoNT/A with no cross-reactivity to other serotypes examined in assay buffers and a variety of body fluids and foodstuffs. When a highly sensitive chemiluminescent substrate was engaged, the detection of 1 pg/mL could be readily achieved within 3h with a linear range of 0.1-1 ng/mL. These results demonstrate that an inexpensive peptide-polymer-based capture ELISA system can be used for rapid, sensitive and highly specific BoNT detection.

Animals↗

Cardiomyocyte-specific deletion of the coxsackievirus and adenovirus receptor results in hyperplasia of the embryonic left ventricle and abnormalities of sinuatrial valves.

The coxsackievirus and adenovirus receptor (CAR), which mediates infection by the viruses most commonly associated with myocarditis, is a transmembrane component of specialized intercellular junctions, including the myocardial intercalated disc; it is known to mediate cell-cell recognition, but its natural function is poorly understood. We used conditional gene targeting to investigate the possible functions of CAR during embryonic development, generating mice with both germline and tissue-specific defects in CAR expression. Homozygous germline deletion of CAR exon 2 or cardiomyocyte-specific gene deletion at embryonic day 10 (E10) mediated by Cre recombinase expressed under the control of the cardiac troponin T promoter resulted in death by E12.5; embryos showed marked cardiac abnormalities by E10.5, with hyperplasia of the left ventricular myocardium, distention of the cardinal veins, and abnormalities of sinuatrial valves. Within the hyperplastic left ventricle, increased numbers of proliferating cells were evident; persistent expression of N-myc in the hyperplastic myocardium and attenuated expression of the trabecular markers atrial natriuretic factor and bone morphogenic protein 10 indicated that proliferating cardiomyocytes had failed to differentiate and form normal trabeculae. In electron micrographs, individual CAR-deficient cardiomyocytes within the left ventricle appeared normal, but intercellular junctions were ill-formed or absent, consistent with the known function of CAR as a junctional molecule; myofibrils were also poorly organized. When cardiomyocyte-specific deletion occurred somewhat later (by E11, mediated by Cre under control of the alpha-myosin heavy chain promoter), animals survived to adulthood and did not have evident cardiac abnormalities. These results indicate that during a specific temporal window, CAR expression on cardiomyocytes is essential for normal cardiac development. In addition, the results suggest that CAR-mediated intercellular contacts may regulate proliferation and differentiation of cardiomyocytes within the embryonic left ventricular wall.

Animals↗

Oxidized low density lipoprotein impairs endothelial progenitor cells by regulation of endothelial nitric oxide synthase.

Oxidized low density lipoprotein (OxLDL) is one of the most important risk factors of cardiovascular disease. Here, we study the impact of OxLDL on endothelial progenitor cells (EPCs) and determine whether OxLDL affects EPCs by an inhibitory effect on endothelial nitric oxide synthase (eNOS). It was found that OxLDL decreased EPC survival and impaired its adhesive, migratory, and tube-formation capacities in a dose-dependent manner. However, all of the detrimental effects of OxLDL were attenuated by pretreatment of EPCs with lectin-like oxidized low density lipoprotein receptor (LOX-1) monoclonal antibody or l-arginine. Western blot analysis revealed that OxLDL dose-dependently decreased Akt phosphorylation and eNOS protein expression and increased LOX-1 protein expression. Furthermore, OxLDL caused a decrease in eNOS mRNA expression and an increase in LOX-1 mRNA expression. These data indicate that OxLDL inhibits EPC survival and impairs its function, and this action is attributable to an inhibitory effect on eNOS.

Apoptosis↗

Therapeutic neovascularization by transplantation of mobilized peripheral blood mononuclear cells for limb ischemia. A comparison between CD34+ and CD34- mononuclear cells.

Autolougous transplantation of granulocyte colony-stimulating factor (G-CSF)-mobilized human peripheral blood mononuclear cells (PBMNCs) improves limb ischemia in patients with arteriosclerosis obliterans of lower extremities and with diabetic foot. However, the mechanism of action of PBMNCs remains elusive. Here, we studied comparatively the effects of the G-CSF-mobilized PBMNCs and CD34-depleted G-CSF-mobilized PBMNCs in an ischemia model of athymic nude mice. Fluorescence- labeled human PBMNCs [1 x 10(6)] were intramuscularly injected into the unilateral ischemic hindlimbs of mice. Laser Doppler imaging analysis revealed a significantly augmented blood perfusion at day 7, 14 and 28 after operation. The capillary density was also markedly increased and the rate of limb loss was significantly reduced in cell-transplanted groups when compared with those in PBS group. In comparison with G-CSF-mobilized PBMNCs, the therapeutic efficiency of G-CSF-mobilized PBMNCs deprived of CD34+ cells was impaired. Transplanted cells were found to accumulate around arterioles and scatter in capillary networks. Incorporation of transplanted cells into new capillaries was observed in the G-CSF-mobilized PBMNCs group, but was not detected in the group deprived of CD34+ cells. There was an elevated expression of VEGF in ischemic tissue. Colocalization of VEGF and transplanted mononuclear cells within adductor tissue was demonstrated. These findings indicate that G-CSF-mobilized PBMNCs promote vascular growth not only by incorporating into vessel walls but also by supplying angiogenic factors. The depletion of CD34+ cells attenuated the therapeutic efficiency of G-CSF-mobilized PBMNCs in response to ischemia-induced neovascularization.

Animals↗

[Application of serum surface-enhanced laser desorption/ionization proteomic patterns in distinguishing non-small cell lung cancer patients from healthy people].

OBJECTIVE: To explore the application of serum surface-enhanced laser desorption/ionization (SELDI) marker patterns in distinguishing non-small cell lung cancer patients from healthy people by protein chip technology. METHODS: One hundred and sixty-three serum samples (123 patients with lung cancer and 40 healthy persons), were randomly divided into a training set [94 cases, 53 non-small cell lung cancer (NSCLC), 21 small cell lung cancer and 20 healthy persons] and a blinded test set (69 cases), were included for analysis by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Five protein peaks at 11,493, 6,429, 8,245, 5,336 and 2,536 were automatically chosen for the system training and the development of a decision classification tree model (marker pattern). The accuracy of the model was tested with the blinded test set (an independent set of masked serum samples from 49 patients with NSCLC and 20 healthy persons). RESULTS: The model differentiated the patients with NSCLC from the healthy people with a sensitivity of 95.9% (71/74) and a specificity of 90.0% (18/20) in the training set and a sensitivity of 83.7%, and a specificity of 80.0% in the blinded set respectively. CONCLUSION: SELDI-TOF-MS technique can correctly distinguish NSCLC patients from healthy people, and it has the potential for the development of a screening test for the detection of NSCLC.

Adult↗

[Correlation between desmin gene, platelet-activating factor acetylhydrolase gene and dilated cardiomyopathy].

OBJECTIVE: To test the Missense mutation of Desmin gene (Ile451Met), the frequency of missense mutation (G994-->T) of Platelet-Activating Factor Acetylhydrolase (PAF-AH) gene, and the correlation between these mutations and dilated cardiomyopathy (DCM) in the Chinese population with DCM. METHODS: A case control study was conducted with 89 DCM patients and 110 healthy people (control group) participating in the study. The exon 8 of Desmin gene and exon 9 of PAF-AH gene were identified by polymerase chain reaction, restriction enzyme digestion, polyacrylamide gel electrophoresis and DNA sequencing for described mutation site of Desmin (Ile451Met) and PAF-AH (Val279Phe). RESULTS: No mutation (Ile451Met) in Desmin gene was found in either the DCM patients or the healthy people. There was no significant difference in the frequency of PAF-AH gene mutation (Val279Phe) between the patient and control groups (P>0.05). CONCLUSION: Neither the mutation of Ile451Met in gene encoding for Desmin exon 8 nor the mutation frequency of PAF-AH gene (G994-->T) has correlation with the DCM.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗

[Detecting the DNA polymorphism of human complement component C8A by PCR-SSCP analysis].

OBJECTIVE: The aim of this study is to establish a new method for detecting the DNA polymorphism of human complement component C8A. METHODS: Based on the point mutation (C-->A) of C8A gene in exon3,The genotypes of 98 unrelated individuals from Han population in Chengdu were studied by polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP)analysis followed by DNA sequencing. RESULTS: The genotypes of C8A * AA, C8A * BB and C8A * AB were observed and the distribution of the genotypes frequencies of C8A in Chengdu Han population was in accordance with Hardy-Weinberg equilibrium. CONCLUSION: The method of PCR-SSCP is reliable, rapid, simple and cost-effective in detecting the DNA polymorphism of C8A, and it is valuable for further application in population genetic study and forensic science practice.

Adult↗

[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↗

[Effects of external counterpulsation on shear stress and production of nitric oxide and cGMP in canines with myocardial infarction].

OBJECTIVE: To investigate the effects of external counterpulsation (ECP) on shear stress and signal transduction in canines with myocardial infarction. METHODS: Nineteen healthy dogs were randomly divided into control, ischemia, and ischemia plus ECP groups. Myocardial infarction was induced in the latter two groups by ligation of the left anterior descending artery (LAD). Serum and aorta NO levels of the dogs were determined by modified nitrate reductase method, and serum and aorta cyclic guanosine monophosphate (cGMP) levels by radioimmunoassay. RESULTS: The shear stress in the truncus brachiocephalicus decreased after LAD ligation, but increased significantly after 2 h of ECP treatment. Serum and aorta NO levels in ECP and control groups were significantly higher than those in the ischemic group (P<0.05). Serum and aorta cGMP levels in control group and ECP group after LAD ligation were also significantly higher than those in the ischemic group (P<0.05). CONCLUSION: ECP can increase the shear stress and increase NO and cGMP levels in dogs with myocardial ischemia, which might be an important mechanism of ECP for protection of the ischemic myocardium.

Animals↗

[Effects of irbesartan on nitric oxide system in the heart of diabetic rats].

OBJECTIVE: To investigate the effects of irbesartan for heart protection and on heart nitric oxide (NO) system in diabetic rats. METHODS: Thirty adult male Wistar rats were randomly divided into three equal groups, namely control group, diabetes group and irbesartan group. Streptozotocin (STZ, 50 mg/kg) was injected to the abdomen to induce diabetes in the rats. After treatment for 12 weeks, the rats were sacrificed and the urine volume, body weight, ratio of heart to body weight, plasma glucose and glycosylated hemoglobin (HbA1c) were measured. NO levels in the serum and myocardium were determined. Inducible nitric oxide synthase (iNOS) expression was determined by immunohistochemistry, and iNOS mRNA detected by RT-PCR. RESULTS: Urine volume, ratio of heart to body weight, plasma glucose, HbA1C, NO levels in the urine, blood and myocardium in diabetic and irbesartan rats were significantly greater than those of normal controls (P<0.05). The ratio of heart to body weight and NO levels of urine, serum and heart tissue in rats of irbesartan group were significantly decreased as compared with those of diabetes rats (P<0.05). Myocardium iNOS mRNA and protein expression decreased significantly in irbesartan group, but not in diabetes group. CONCLUSIONS: The abnormality in NO and iNOS mRNA expression might be related to diabetic cardiomyopathy. Irbesartan can decrease iNOS mRNA and protein expressions and reduce NO levels in STZ-induced diabetic rats.

Angiotensin II Type 1 Receptor Blockers↗

[Fusion expression of O type foot-and-mouth diseases virus VP1 gene and HSP70 gene and induction of immune responses in mice].

Vp1 gene of O type foot-and-mouth diseases virus and M. tuberculosis HSP70 were expressed in methylotrophic yeast Pichia pastoris expression system. The results of cellular immune responses and humoral immune response were examined after BALB/c mice were immunized with fusion protein expressed in methylotrophic yeast Pichia pastoris. The genes was cloned into the vector pPICZalpha-A by routine molecular technique. The plasmid fusion (pPICZalphaA-vp1-HSP70) was created that HSP70 located downstream of VP1 gene of O type foot-and-mouth disease virus. Vp1 was expressed by fusing to the amino terminus of M. tuberculosis hsp70 in yeast Pichia pastoris. The recombined fusion plasmid was transformed into methylotrophic yeast Pichia pastoris X-33 by electrophoration. The recombinant transformants were selected by Zeocin and induced by the addition of methanol every 24h. The expressived product analyzed by SDS-PAGE and Western blotting. The result indicated that the fusion protein(vp1-HSP70) has specific antigenicity. Mice were inoculated transcutaneous three times at a two-weeks interval with fusion protein, PBS and conventional inactivated vaccines. To evaluate the prophylaxtic efficacy of fusion protein, Titers of antibodies was detected by ELISA and proliferation of lymphocytes were determined by MTT. The results indicated that fusion protein could elicit specific humoral immune and cellular immune responses. Compared with conventional inactivated vaccines, fusion protein elicited slightly lower FMDV antibody level but stronger T cell proliferation.

Animals↗

[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↗

[Effects of Sini decoction on vascular stenosis after iliac artery balloon injury and oxidative stress in rabbits].

OBJECTIVE: To investigate the effect of Sini decoction (SND) in preventing vascular restenosis and protecting against oxidative stress after rabbit iliac artery balloon injury. METHODS: Twenty-four male New Zealand albino rabbits were equally randomized into control group, model group and SND group. Rabbits in the control group were fed with common forage, and those in the model and SND groups with high-fat diet. Two weeks later, the iliac arteries of the rabbits in the latter two groups were subjected to balloon injury. Four weeks after the operation, the rabbits were killed and the vascular structure was observed by scanning electron microscope and optical microscope, with the serum cholesterol level, superoxide dismutase (SOD) activity and malondialdehyde (MDA) level determined. RESULTS: Scanning electron microscopy showed that the endothelial cell lining in the iliac artery of the control and SND group remain regular, but the arteries in the model group presented with desquamated and exposure of the collagen fibril beneath the endothelium. Optical microscope revealed narrowed vascular lumen, thicken intima and numerous arteriosclerotic plaques in the model group in comparison with the control group, whereas the vascular lumen and intima thickness remained basically normal in SND group. The levels of total cholesterol, low-density lipoprotein cholesterol and triglyceride were decreased with high-density lipoprotein cholesterol levels increased in SND group, which was not observed in the model group. The serum SOD activity was higher in the control group than in the model and SND groups, but SND group had higher serum SOD activity than the model group. The serum MDA level was lower in the control group than in the other two groups, but SND group had lower MDA level than the model group. CONCLUSION: SND can alleviate intimal hyperplasia and vascular stenosis in injured rabbit iliac artery, possibly in relation to increased SOD activity and decreased lipid peroxidation as a result of SND treatment.

Angioplasty, Balloon, Coronary↗

[Study on the preparation and quality standard of Ephedra sinica dispensing granules].

OBJECTIVE: To optimize the preparation process and to set up the quality standard of Ephedra sinica Dispensing Granules. METHODS: Nine experiments were carried out by L9 (3(4)) orthogonal design. Ephedra sinica Dispensing Granules was identified by TLC and the content of ephedrine was determined by HPLC. RESULTS: The optimal extraction process was as follows: the water that 10 times of Ephedra sinica, was decocted 3 times and each time was sustained for 1.5 hours. The linear relationship of ephedrine hydrochloride was at the range of 0.0081 - 0.1377 microg (r = 0.999 9). The average recovery was 100.25% ( RSD = 2.24%, n = 6). CONCLUSION: The extraction process is scientific. The method is available with a good reproducibility and can control the quality of Ephedra sinica Dispensing Granules.

Chromatography, High Pressure Liquid↗

Exploring the scope of the 29G12 antibody catalyzed 1,3-dipolar cycloaddition reaction.

[Chemical reaction: See text] 29G12 is a murine monoclonal antibody programmed to catalyze the regio- and enantioselective 1,3-dipolar cycloaddition reaction between 4-acetamidobenzonitrile N-oxide 1a and N,N-dimethylacrylamide 2a (Toker, J. D.; Wentworth, P., Jr.; Hu, Y.; Houk, K. N.; Janda, K. D. J. Am. Chem. Soc. 2000, 122, 3244). Given the unique nature of 29G12 as a protein biocatalyst for this chemical reaction, we have investigated both the substrate specificity and mechanistic parameters of the 29G12-catalyzed process. These studies have shown that while 29G12 is specific for its dipole substrate 1a, the antibody is highly promiscuous with respect to the dipolarophiles it can process. 29G12 accepts a bulky hydrophobic dipolarophile cosubstrate, with rates of product formation up to 70-fold faster than with the original substrate 2a. In all cases, the respective isoxazoline products are produced with exquisite regio- and stereochemical control (78-98% ee). Comparison between the steady-state kinetic parameters from the 29G12-catalyzed reaction of 1a with the most efficient versus the original dipolarophile cosubstrate (2m and 2a, respectively), reveals that while the effective molarities (EM)s are almost identical (EM(2m)) 26 M; EM((2a)) 23 M), the affinity of 29G12 for the larger dipolarophile 2m is more than 1 order of magnitude higher than for 2a [Km(2m) 0.44 +/- 0.04 mM; Km(2a) 5.8 +/- 0.4 mM]. Furthermore, when 2m is the cosubstrate, the affinity of 29G12 for its dipole 1a is also greatly improved [Km(1a) 0.82 +/- 0.1 mM compared to Km(1a) 3.4 +/- 0.4 mM when 2a is the cosubstrate]. An analysis of the temperature dependence of the 29G12-catalyzed reaction between 1a and 2m reveals that catalysis is achieved via a decrease in enthalpy of activation (DeltaDeltaH 4.4 kcal mol(-1)) and involves a large increase in the entropy of activation (DeltaDeltaS 10.4 eu). The improved affinity of 29G12 for the nitrile oxide 1a in the presence of 2m, coupled with the increase in DeltaDeltaS during the 29G12-catalyzed reaction between 1a and 2m supports the notion of a structural reorganization of the active site to facilitate this antibody-catalyzed reaction.

Acrylamides↗

Application of serum SELDI proteomic patterns in diagnosis of lung cancer.

BACKGROUND: Currently, no satisfactory biomarkers are available to screen for lung cancer. Surface-Enhanced Laser Desorption/ionization Time-of-Flight Mass Spectrometry ProteinChip system (SELDI-TOF-MS) is one of the currently used techniques to identify biomarkers for cancers. The aim of this study is to explore the application of serum SELDI proteomic patterns to distinguish lung cancer patients from healthy individuals. METHODS: A total of 208 serum samples, including 158 lung cancer patients and 50 healthy individuals, were randomly divided into a training set (including 11 sera from patients with stages I/II lung cancer, 63 from patients with stages III/IV lung cancer and 20 from healthy controls) and a blinded test set (including 43 sera from patients with stages I/II lung cancer, 41 from patients with stages III/IV lung cancer and 30 from healthy controls). All samples were analyzed by SELDI technology. The spectra were generated on weak cation exchange (WCX2) chips, and protein peaks clustering and classification analyses were made using Ciphergen Biomarker Wizard and Biomarker Pattern software, respectively. We additionally determined Cyfra21-1 and NSE in the 208 serum samples included in this study using an electrochemiluminescent immunoassay. RESULTS: Five protein peaks at 11493, 6429, 8245, 5335 and 2538 Da were automatically chosen as a biomarker pattern in the training set. When the SELDI marker pattern was tested with the blinded test set, it yielded a sensitivity of 86.9%, a specificity of 80.0% and a positive predictive value of 92.4%. The sensitivities provided by Cyfra21-1 and NSE used individually or in combination were significantly lower than that of the SELDI marker pattern (P < 0.005 or 0.05, respectively). Based on the results of the test set, we found that the SELDI marker pattern showed a sensitivity of 91.4% in the detection of non-small cell lung cancers (NSCLC), which was significantly higher than that in the detection of small cell lung cancers (P < 0.05); The pattern also had a sensitivity of 79.1% in the detection of lung cancers in stages I/II. CONCLUSION: These results suggest that serum SELDI protein profiling can distinguish lung cancer patients, especially NSCLC patients, from normal subjects with relatively high sensitivity and specificity, and the SELDI-TOF-MS is a potential tool for the screening of lung cancer.

Adult↗