Biomedical subjects

Jun Zhang

Publications and source records attributed to Jun Zhang.

At least 235 records · Page 13Linked to original sources

PubMed2005

[Study on temperature correctional models of quantitative analysis with near infrared spectroscopy].

Effect of enviroment temperature on near infrared spectroscopic quantitative analysis was studied. The temperature correction model was calibrated with 45 wheat samples at different environment temperaturs and with the temperature as an external variable. The constant temperature model was calibated with 45 wheat samples at the same temperature. The predicted results of two models for the protein contents of wheat samples at different temperatures were compared. The results showed that the mean standard error of prediction (SEP) of the temperature correction model was 0.333, but the SEP of constant temperature (22 degrees C) model increased as the temperature difference enlarged, and the SEP is up to 0.602 when using this model at 4 degrees C. It was suggested that the temperature correctional model improves the analysis precision.

Algorithms↗

PubMed2005

[Noninvasive assessment of left anterior descending and right coronary artery flow reserve by transthoracic Doppler echocardiography in patients with coronary artery disease].

OBJECTIVE: To assess the feasibility of evaluation of CFR for LAD and right coronary artery (RCA) as well as diagnostic accuracy for patency of each vessel by transthoracic Doppler echocardiography (TTDE). METHODS: 65 consecutive patients (age 58 +/- 14, ejection fraction 49% +/- 8%, 48 men and 17 women) were studied for CFR by TTDE with adenosine infusion (140 microg.kg(-1).min(-1)). LAD flow was interrogated nearby the apex in modified 2-ch apical view. RCA flow was interrogated at mid posterior wall on distal part of the posterior descending branch (PDA) in modified 2-ch apical view for PDA. RESULTS: Flow for LAD was detected in all patients (4 with use of contrast agent) and for RCA in 55 patients (5 with contrast agent). Two patients had an occluded RCA. Feasibility of RCA flow detection was 55/63 (87%). In all patients maximal flow of each branch was detected in less than 2 min of adenosine infusion (140 mg.kg(-1).min(-1)). Total time for both CFR estimation was 7.3 +/- 1.6 min. Selecting 2.0 or 1.8 as CFR cut-off value for diagnosis of coronary stenosis (> or = 50% in diameter) or severe stenosis (> or = 70%) was found fitted for both LAD and RCA with similar diagnostic performance (sensitivity 89%/93%, specificity 86%/84%, area under curve 0.89/0.92 respectively, in stenosis diagnosis and sensitivity 88%/89%, specificity 90%/83%, area under curve 0.94/0.95 respectively in severe stenosis diagnosis). CONCLUSIONS: CFR evaluation of both distal LAD and PDA is of high feasibility and can provide high diagnostic yield for relevant vessel patency.

Adult↗

PubMed2005

[Correlation study between sex and age of patients and root resorption after orthodontic treatment].

PURPOSE: To investigate the relationship between root resorption related to fixed appliance and the variables including sex, age. METHODS: 44 patients were divided into four groups according to sex and age: juvenile males, juvenile females, adult males, adult females. The length of incisors was calculated according to orthopantomograph and study models of pre- and post-treatment, and the relationship between patients' sex and age and root absorption pre- and post-treatment was analyzed by paired t test. RESULTS: Root absorption occurred in every patient. There was no significant difference between the same-age groups of males and females (P<0.05); However, there was significant difference between adult groups (both males and females) and juvenile groups (P<0.01). CONCLUSION: Root absorption occurs in every fixed-appliance case. Fixed-appliance-caused root absorption has no significant correlation with sex;however, absorption of adult groups is of higher level than that of juvenile groups.

Adolescent↗

PubMed2005

[A theoretical model study of open section effect on the mechanical properties of long bone].

The mechanical model of femur mid-diaphysis with a rectangular open section in the exterior cortex was developed and a finite element method was adopted in calculating and analysing the changes of torsional stiffness and the stress distribution when the dimension of the open section altered. It showed that the open section with a length of 1 OD (femur mid-diaphysis diameter) had little influence on the femur torsional stiffness or stress distribution. The torsional stiffness decreased most dramatically as the length increased from 2 to 4 OD. Shear stress peaked at the center of the open section. This conclusion provides an important theoretical ground for the operative methods and the dimension control of an open section in clinical orthopaedics.

Biomechanical Phenomena↗

PubMed2005

Diagnosis and treatment of diffuse axonal injury in 169 patients.

OBJECTIVE: To evaluate current diagnosis and therapeutic effect and outcome of diffuse axonal injury (DAI) in 169 patients. METHODS: The data of 169 DAI patients treated in the Second, Sixth, Eighth and Ninth Hospitals of Shenzhen and Shekou Hospital from January 2001 to January 2005 were collected. The imaging features, classification, GCS (Glasgow coma scale), treatment and outcome of the 169 patients were retrospectively analyzed. RESULTS: The simpler the imaging features, the closer the focus of DAI to the periphery of hemisphere and the higher the GCS score, the better the prognoses of DAI patients will be. CONCLUSIONS: The prognoses of DAI patients are closely related to the imaging features and classification, GCS and clinical treatment.

Journal Article↗

PubMed2005

[A method of HPRE synthesis via transcription by T7 RNA polymerase in vitro].

OBJECTIVE: To synthesize highly pure HBV post-transcriptional regulatory element (HPRE) via transcription in vitro by T7 RNA polymerase. METHODS: HPRE gene was amplified by PCR from a template containing HBV complete genomic DNA and cloned into plasmid pGEM-11zf. The cloned DNA sequence was transcribed by T7 RNA polymerase. RESULTS: The construction of HPRE gene recombinant plasmid and production of HPRE via transcription in vitro was successful. CONCLUSION: In vitro transcription by T7 RNA polymerase can be used to synthesize highly pure HPRE.

DNA-Directed DNA Polymerase↗

PubMed2005

[Isolation, induction and differentiation of human blood-derived endothelia progenitor cells].

OBJECTIVE: To determine the biological traits and optimal condition for the induction and differentiation of endothelial progenitor cells from peripheral blood in healthy adults. METHODS: Mononuclear cells isolated from peripheral blood of healthy adults were cultured in M199 medium supplemented with VEGF, bFGF, IGF-1, and EGF. The appearing time of cell clusters or spindle-shaped cells was recorded respectively. Attached spindle-shaped cells were detached and labeled with a series of antibodies against blood vessel endothelial-specific markers. RESULTS: Attached spindle-like cells appeared 4 days after the culture, cell clusters were observed at 5 to 8 days, and cord-like structure was formed by 10th day. These cells expressed endothelial-specific markers. CONCLUSION: Endothelial progenitors cells were derived from mononuclear cells of peripheral blood, which can be induced into endothelial cells at specific conditions.

Cell Differentiation↗

PubMed2005

[Effects of simvastatin on TGF-beta system of diabetic rat kidneys].

OBJECTIVE: To investigate the effects and mechanism of renal benefit of simvastatin on diabetic rat kidneys. METHODS: Twenty STZ-induced SD rats and 10 normal rats were assigned to diabetic rat (DM) group, simvastatin [ 4 mg/( kg x d) ] treatment (S) group and normal control (C) group. Immunohistochemistry, RT-PCR and western-blot were employed to examine the changes of the mRNA and protein expression of TGF-beta1 and Tbeta II R in the kidneys of the rats. RESULTS: Compared with the normal control group, both the mRNA and protein expression of TGF-beta1 and Tbeta II R in the diabetic rat group and treatment group were significantly increased (P < 0.05). Compared with the diabetic rat group, simvastatin could markedly decrease the mRNA and protein expression of TGF-beta1 and Tbeta II R (P < 0.05). CONCLUSION: Simvastatim may play a protective role in the diabetic kidneys by down-regulating TGF-beta1 and Tbeta II R and inhibiting the TGF-beta signal pathway.

Animals↗

PubMed2005

[Study on the effect of spinal neural progenitor transplantation on treating brachial].

OBJECTIVE: To explore the effect of spinal neural progenitor transplantation to the cervical spinal on The brachial plexus treating brachial plexus injury with the reimplantation of the avulsed spinal roots. METHODS: avulsed injury model was made on 54 rats and they were evenly divided into 3 groups: fresh group, chronic group, control group. The spinal neural progenitor was cultured and identified. Then 10 microl (1 x 10(5)/microl) cells were labelled with BrdU and transplanted into the fresh group (15 rats survived, being model for 1 week) and the chronic group (14 rats survived, being model for 2 months). No cell was transplanted into the control group. Two months after the transplantation, the recovery of function of the injured limb was evaluated. Electrophysiologic study and immunohistochemical study of the injured limb were made. RESULTS: Spinal neural progenitors were isolated from the spine and became neural sphere. The neural spheres were differentiated into neurons and astrocytes. Fourteen rats out of 15 in the fresh group were recovered, 7 rats out of 14 in the chronic group were recovered, and 5 rats out of 12 in the control group were recovered. Immunohistochemical study indicated that the transplanted progenitors in fresh group survived and differentiated into the neural cells, and the transplanted progenitors in chronic group existed and did not differentiate well. CONCLUSION: Transplanted spinal neural progenitors can promote the recovery of the brachial plexus injury with the reimplantation of the avulsed spinal root.

Animals↗

PubMed2005

[Effects of yinxing pingchan recipe and its components on activity of mitochondrial enzyme complex in brain of mice with Parkinson's disease].

OBJECTIVE: To investigate the mechanisms of Yinxing Pingchan recipe (YXPC) and its components, i.e. the components for detoxicating (A), for calming liver (B) and for dissolving blood stasis(C), in preventing and treating Parkinson's disease, and the path of its inhibition on nigrostriatal dopaminergic neuron (DAn) apoptosis in model mice of Parkinson's disease. METHODS: Male C57BL/6J mice were divided into the normal group, the model group and four Chinese medicinal groups, that is, the YXPC group, and Group A, B and C, treated with YXPC and its components A, B and C respectively. Mouse model of Parkinson's disease was established by intraperitoneal injection with 1-methl-4-phenyl-1,2,3,6-tetrahydropyridin (MPTP). All mice were sacrificed in 2 batches at the 14th and the 28th day respectively. The activity of mitochondrial enzyme complex I, II and IV (MEC I, II and IV) in the brain of mice were measured, respectively. RESULTS: As compared with the normal group, the activity of MEC I and IV in brain was significantly lower (P < 0.05 or P < 0.01), and that of MEC II had no obvious change in the model group. As compared with the model group, the activity of MEC I was significantly higher in YXPC group and Group C at the 14th day (P < 0.05), while the activity of MECII in Group A at the 14th day, Group B at the 28th day and Group C at both 14th and 28th day was significantly lower (P<0.05 or P<0.01). Activity of MEC IV in the four Chinese medicinal groups at the 14th day all significantly increased (P<0.05 or P<0.01), and retained at high level in Group B and Group C at the 28th day (P<0.05). CONCLUSION: YXPC and its components can maintain the mitochondrial function by partial inhibiting the activity of its enzyme complex, preventing DAn apoptosis to slow down the progress of Parkinson's disease.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed2005

[The promoter activity of the DNA sequence corresponding to HCV 5'UTR in HepG2].

OBJECTIVE: To study the promoter activity in HepG2 cells of the DNA sequence corresponding to the HCV 5'UTR. METHODS: Plasmids, 5'UTR-Luc(+) and 5'UTR-Luc(-) carrying the forward and reverse DNA sequences corresponding to the HCV 5'UTR respectively were constructed, and subsequently transfected into HepaG2 cells. The luciferase activity and the mRNA of the luciferase gene were then detected. The 5'UTR sequence was cloned into a GFP vector to make 5'UTR-EGFP, and then the GFP expression was confirmed by fluorescence microscopy. RESULTS: 5'UTR-Luc(+) had an obvious luciferase activity whereas 5'UTR-Luc(-) had nearly no luciferase activity. The former had a high level of luciferase mRNA while the latter could not be detected. An intense green fluorescence expression was observed in the cells transfected with the plasmid of 5'UTR-EGFP. CONCLUSION: The forward DNA sequence corresponding to HCV 5'-UTR had an obvious promoter activity in hepG2 cells. It may play an important role in the replication of HCV.

5' Untranslated Regions↗

PubMed2005

[Structure of nasal cavity and characters of airflow].

OBJECTIVE: To study the airflow in nasal cavity by reconstructing 20 volunteers' nasal cavity models and numerical simulation of the flow field in these nasal cavity models. METHODS: Based on the data from the CT images, 20 volunteers' nasal cavity models were reconstructed by the method of surface rendering. The flow field in these three-dimensional models were simulated with finite element method. Some of these volunteers were tested by means of acoustic rhinometry and the test results recorded. Comparisons were performed for the curves from acoustic rhinometry and the results of numerical simulations. The simulation results were explained with the fluid network theory. RESULTS: The airflow distribution in the nasal cavity model could be acquired from the simulation results of the velocity plot. Main airflow would pass through the common nasal meatus in which flux accounted for 50% - 77% of overall flux. The pressure value at any point in the nasal cavity model could be obtained from the results of the pressure plot. The nasal airway resistance in the region of limen nasi accounted for 50% - 65% of overall nasal airway resistance. Comparing the test results with the simulation results the relation could be understood between the change of the cross-section area of nasal cavities and the plot of numerical simulation results of velocity and pressure in airflow field in the nasal cavity models. CONCLUSIONS: Comparing the simulated results of the 20 volunteers' nasal cavity model it can be concluded that the distribution of airflow in nasal cavities is not stationary. The differences among everybody's nasal cavity structure lead to the different airflow distribution in the nasal cavities.

Adult↗

PubMed2005

[Application of lacrimal plug for dry eye patients].

OBJECTIVE: To observe the availability and efficacy of Smart PLUG in lacrimal plug in the treatment of serious dry eye. METHODS: Lacrimal plug was applied in 43 patients (72 eyes) in our clinic from July to October in 2004. Questionnaire was used in these patients before the surgery 3 days and repeated after surgery 1 week and 3 months. Slit lamp microscope examination, fluorescent staining for tear break-up time (BUT), Schirmer test I (STI), impression cytology (IC) were carried out at the same time. RESULTS: Questionnaire indicated most patients complained about dry eye, foreinbody sensation, asthenopia and red eye. These symptoms were relieved obviously after the application of lacrimal plug. Compared with pre-operation, tear production was increased significantly on the surface of eyes and the defect of corneal epithelium was healed in 37 patients (62 eyes). Compared with pre-operation, BUT and STI were increased and elongated on these patients, IC suggests squamous metaplasia of epithelial layer of conjunctiva in these patients was improved. CONCLUSIONS: Symptoms of patients suffered from dry eye were relieved obviously by using Smart PLUG. Therefore lacrimal plug can be used for patients with serious dry eye by improving tear volume and tear film stability.

Adult↗

PubMed2005

[Effect of low stress environment on bone density and geome-morphology of rat femur].

6-week old rats were subjected to sciatic nerve resection and the right hindlimbs were then under a low stress environment. Bone mineral density (BMD) of different regions and geome-morphological parameters of femurs were measured. The results showed that the increase in the diameter, subperiosteal area and bone mineral density of femurs were suppressed obviously under low stress environment. But the sensitivity of BMD of different regions of the femur to the low stress environment was different. The suppression of the increase in femoral BMD was composed of an early impairment in the gain of BMD at the femoral metaphysis, which is rich in trabecular bone, and a sustained reduction in the gain of BMD at the femoral diaphysis, which is rich in cortical bone. The results of geome-morphology suggested that the early reduction in the increase of BMD at the metaphysis was due to an enhancement of bone resorption, whereas the suppression of gain in cortical bone mass and size is the result of a sustained reduction of periosteal bone formation.

Animals↗

PubMed2005

[Transcription factor Sp1 expression in gastric cancer and its prognostic value].

OBJECTIVE: To investigate the expression of transcription factor Sp1 in human gastric cancer tissues and normal gastric mucosa, and its prognostic significance. METHODS: By using immunohistochemistry, we studied the Sp1 expression patterns in 65 cases of gastric cancer with various clinico-pathologic characteristics, and 40 normal gastric mucosa specimens obtained from patients who underwent partial gastrectomy for benign gastric diseases. The significance of Sp1 expression on the survival of patients was evaluated. RESULTS: The expression rate of Sp1 in normal gastric mucosa was 12.5% (5/40). The positively stained glandular cells were mainly limited to those in the neck region. Cells at the basal portion of the gland were essentially negative. In sharp contrast, Sp1 expression rate in gastric cancer lesions was 53.8% (35/65). The medium survival time in patients who had a tumor with negative, weak and strong Sp1 expression was 1700, 1560 and 1026 days, respectively (P = 0.036). Sp1 protein expression was closely related to the depth of tumor invasion and TNM stage (P = 0.001, P = 0.026), but not related to the number of metastatic lymph nodes and Lauren's classification (P = 0.306, P = 0.667). CONCLUSION: Normal and malignant gastric tissues have unique Sp1 expression patterns. Sp1 might be served as an independent prognostic factor.

Adenocarcinoma↗

PubMed2005

[Studies on the resources survey methods of Panax notogingseng based on remote sensing].

OBJECTIVE: To explore the survey methods for the cultivated medicinal plant resources such as Panax notogingseng based on remote sensing. METHOD: Through the preliminary study by remote sensing technique and field survey in the study area, the optimal methods in the procedure were chosen for the survey. RESULT: In this study,a set of survey method for P. notogingseng based on remote sensing technique was founded, which included the remotely sensed data-source selecting, the remote sensing image processing, interpretation and validation etc. CONCLUSION: With different resolution remotely-sensing data at the study area, the area, the natural storage and the yield of P. notoginseng were calculated. For Maguan county, with SPOT5 (5 m), the relative right rate of judgement, the relative precision of area and the relative precision of yield with statistics was 92.7%, 94.4% and 78.2% separately, and with TM (30 m), the relative right rate of judgement, the relative precision of area was only 71.4% and 58.8%, though, for Qiubei county, with TM (30 m), the relative precision of area with statistics could reach 74.7%, which showed that choosing appropriate remotely-sensing data and processing methods for different area, the remote sensing technique is feasible for resource survey of cultivated medicinal plants such as P. notoginseng.

China↗

PubMed2005

[Toxin-neutralizing monoclonal antibodies to the different domains of anthrax protective antigen].

Anthrax toxin from Bacillus anthracis is a three-component toxin consisting of lethal factor (LF), edema factor (EF), and protective antigen (PA). PA binds to target cells and transports LF or EF into the cell cytosol where they carry out their enzymatic functions. PA can induce protective immunity to the infection of the bacterium and is the major component in the only anthrax vaccine approved by FDA of USA. Mouse hybridoma clones specifically secreting anti-PA monoclonal antibodies (MAbs) were generated by cell fusion technique and their ability to neutralize anthrax lethal toxin activities was screened in vitro on a toxin-sensitive cell line. Nine toxin-neutralizing MAbs obtained were then characterized for the domains of PA they recognize, and the epitope regions they bind were analyzed by competitive binding ELISA. It was found that these MAbs bind four potential neutralizing epitope regions in three different domains of PA. Four MAbs bind to two non-overlapping epitope regions in domain 4 of PA and may prevent the binding of PA to its cell receptor. Four MAbs bind to domain 2, a domain involved in membrane insertion. One MAb binds to domain 3, a region involved in the oligomerization of PA. The results provided supporting evidence that PA has several neutralizing epitopes, and offered potential immunotherapeutic agents for the treatment of anthrax.

Animals↗

PubMed2005

[Study on the metabolic health risks of body mass index and waist circumference].

OBJECTIVE: To evaluate the effect of body mass index (BMI) and waist circumference (WC) on metabolic health risks (MHR). METHODS: Based on data from two community populations (Suzhou city and Changshu city) derived from a project on 'multiple metabolic disorders and metabolic syndrome' in Jiangsu province. 1604 subjects were divided into groups as normal weight (BMI: 18-23.9), overweight (BMI: 24-27.9) and obesity (BMI > or = 28) according to BMI measurement. According to the results from WC measurement, they were grouped as abdominal obesity (male: > or = 85 cm; female: > or = 80 cm) and normal. Relative risks (RR) for hypertension, hyperglycemia, dyslipidemia were calculated. RESULTS: In males and females, the mark values of hypertension, hyperglycemia, dyslipidemia as well as the prevalence of MS were related to BMI and WC. The relativity remained true when the confounding factors were under control. Among the overweight group, the aRR of all these metabolic health risks were basically lower than those when the overweight group and the abdominal obesity group were combined. Both in males and females, when groups combining normal weight with abdominal obesity group, the aRR of all these metabolic health risks were higher than overweight group combining with normal WC group in most of the cases. CONCLUSION: As to the effect of BMI and WC on metabolic health risks, WC--the mark of abdominal obesity seemed to be more effective than BMI.

Body Mass Index↗