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Biomedical subjects

J Zeng

Publications and source records attributed to J Zeng.

At least 37 records · Page 2Linked to original sources
PubMed2001

[GC-MS analysis of supercritical carbon dioxide extraction products from pericarp of Zanthoxylum bungeanum].

The chemical constituents of supercritical carbon dioxide extraction products from pericarp of Zanthoxylum bungeanun Maxim. were studied by GC-MS-DS. Forty-five compounds which account for 86.76% of the area of the chromatographic peaks were identified. The results showed that the main components of the extracts are beta-pinene (10.33%), 1,8-terpinene (7.6%), cis-piperitol acetate (7.07%), oleic acid (5.46%), palmitic acid (5.41%) and 4-terpineol, (43.7%), et al.

Carbon Dioxide↗
PubMed2001

[Supercritical and near-critical fluid solvents assisted reaction and separation processes].

The tunability of supercritical and near-critical fluid (S/NCF) solvents offers environmental improvements and economic advantages from improved performances and flexibility for separation and reaction processes through density changes or cosolvents. The paper reviews the sustainable reaction and separation processes in S/NCF solvents such as supercritical carbon dioxide and near-critical water.

Acids↗
PubMed2001

[Dynamic analysis of incidence and mortality of stroke and the risk factors in the communities in Shanghai, in the 1990's].

OBJECTIVE: To understand the trend of incidence, mortality of stroke and the risk factors at the community level in the 1990's. METHODS: To establish a network of disease surveillance. Both incidence and mortality of stroke were surveyed in the 35 - 74 age group during 1991 - 1999 using the method of WHO MONICA. By cluster sampling in 1992 and 1998, 500 individuals aged 35 - 59 from each female and male group were investigated respectively on the risk factor of stroke. RESULTS: The incidence of stroke was averaged 168.2 per 100 000 in the group aged 35 - 79 during 1991 to 1999 with 194.5 and 144.9 pre 100 000 respectively for the male and female group of this age. The incidence of stroke in the male group was higher than that in the female group, also with a faster speed of increase in the male group. The overall mortality of stroke was averaged 79.2 per 100 000 with 87.2 and 71.4 per 100 000 in male and female groups respectively of this age group. The incidence of stroke increased with age in both male and female groups. The average age of onset had been 66.1 year olds during 1996 - 1999, 3.5 years older than that age groups during 1991 - 1995, but did not show much difference between male group and female group. CHO, Blood Pressure, BMI, Prevalence of Hypertension, TC/HDLC, WHR, Prevalence of High-CHO, Prevalence of Low-HDL all had a tendency of increase in both male and female groups. The rates of smoking cigarettes and drinking alcohol both decreased, especially in the male group. CONCLUSION: The incidence of stroke and some relative risk factors seemed to increase in the 1990's, but the mortality of stroke had a decrease in the same period in the communities in Shanghai.

Adult↗
PubMed2001

[Studies on saponin accumulative in regularities Panax notoginseng (Burk) F. H. Chen].

OBJECTIVE: To determine the optimal harvest time for P. notoginseng through studying the changes of saponin contents with growth periods. METHODS: P. notoginseng samples were collected from the experimental plot regularly, and then the contents of total saponin and some main single saponins were analyzed by HPLC. RESULTS: Total saponin contents decreased from April through July, and increased from August through December. CONCLUSION: The optimal harvest time is determined as from October through December, which corresponds to the traditional harvest time.

Ginsenosides↗
PubMed2001

[The effect of leukotriene antagonist on the parameters of dose-response curve obtained after methacholine challenge test].

OBJECTIVE: To investigate the effect of leukotriene antagonist (zafirlucast) on the parameters of dose-response curve (DRC) obtained after methacholine challenge test. METHODS: A therapy trial was conducted with the use of zafirlucast in 20 cases of cough variant asthma (CVA) and 20 cases of asthma. Placebo was used in 4 cases of CVA and 10 cases of asthma for comparison with the two therapy groups respectively. Before and after the zafirlucast treatment a series of parameters of DRC were obtained after the methacholine challenge test and were calculated. These included the response threshold (PC35sGaw), the dose-response slope (DRS), the ratio of the area under the curve to the logarithm of the maximal concentration (AUC/1 g[Cmax]), and the maximal response. RESULTS: Zafirlucast significantly increased the PC35sGaw in the CVA and asthma groups. It conspicuously decreased all the parameters of DRS and AUC/1 g[Cmax] except for maximal response in the cases of CVA, and it had no significant effects on all the parameters of DRS and AUC/1 g[Cmax] except for PC35sGaw in the cases of asthma. CONCLUSION: Short-term use of Zafirlucast in asthmatic patients could improve the parameters of dose-response curve obtained after the methacholine challenge test.

Adult↗
PubMed2001

[A comparison between the effects of albuterol and isoproterenol in bronchodilation test].

OBJECTIVE: To compare albuterol with isoproterenol as a bronchodilator in pulmonary function test and their value in the diagnosis and differential diagnosis of asthma. METHODS: Two groups (59 patients with asthma and 37 patients with COPD) were included in this study, and the patients of each group were randomly divided into 2 subgroups. The patients in the 2 subgroups inspired the two drugs in a cross-over by odd or even days. The pulmonary functions were evaluated. RESULTS: The changing rates of pulmonary functions induced by the two drugs in the two groups were positively correlated (P < 0.005), The changing rates of FEV1, MMEF, Raw, sGaw induced by albuterol were higher than the ones induced by isoproterenol in patients with asthma(P < 0.02), however the changing rates of FVC and PEF in asthma cases and all the above parameters in COPD cases were not significantly different between the two drugs(P > 0.10). The comparison of positive case number between asthma and COPD cases induced by both drugs showed significant difference(P < 0.005); especially, when the positive rate of sGaw induced by albuterol in asthma cases reached 98%, the positive rates in COPD cases was generally much lower. CONCLUSION: Bronchodilation test is a valuable diagnostic method for asthma. In this study, albuterol was superior to isoproterenol. The most sensitive index in bronchodilation test was sGaw, then in order, FEV1(92%), MMEF and Raw; the FVC and PEF were relatively insensitive.

Adult↗
PubMed2001

[Evaluating wall motion of dilated cardiomyopathy by pulsed-wave Doppler tissue imaging].

OBJECTIVE: To evaluate the characteristics of wall motion in cases of dilated cardiomyopathy (DCM) by the use of Doppler tissue imaging (DTI). METHODS: We observed 30 DCM patients and 30 normal volunteers. For the assessment of short axis motion, the myocardial velocities (MV) and transmural myocardial velocity gradients (MVG) of the middle segments of anterior interventricular septum and left ventricular posterior wall were recorded through parasternal long axis view. We detected the MV of the middle segments of left ventricular walls to evaluate the long axis motion through apical windows(4-chamber, 2-chamber and long axis). RESULTS: Four kinds of abnormal presentations of the waves were seen in DCM cases. The patients' MV of were obviously lower as compared with the controls', especially in long axis; the patients' MVG also decreased significantly (P < 0.05). In the patient group, the heterogeneity of wall motion disappeared too. CONCLUSION: PW-DTI can quantitatively assess the above abnormalities of DCM and provide supplementary information for clinical use.

Adolescent↗
PubMed2001

[Measurement of the parameters of dose-response curve obtained after the methacholine challenge test].

OBJECTIVE: To investigate the clinical value in the measurement of parameters of the dose-response curve (DRC) obtained after the methacholine challenge test. METHODS: Twenty-seven cases of cough variant asthma (CVA), 29 of mild asthma, 19 of moderate asthma, and 15 healthy volunteers underwent the methacholine challenge test. The dose-response curves were constructed. The following parameters were calculated: position (PC35sGaw), dose-response curve (DRS), ratio of the area under the curve to the logarithm of the maximal concentration (AUC/lg[Cmax]) and maximal response. RESULTS: A plateau appeared in 11 cases among the healthy subjects, while a plateau appeared only in 2 cases of CVA and 2 of asthma. There were no significant differences among the asthmatic groups in the measurements of PC35sGaw and AUC/lg[Cmax] (geometric mean PC35sGaw: mild asthmatics = 0.369, moderate asthmatics = 0.251, cough variant asthmatics = 0.547), AUC/lg[Cmax] was significantly greater in the asthmatic groups than in the normal group [AUC/lg [Cmax](mean +/- s): mild asthmatics = 24.7 +/- 4.7, moderate asthmatics = 26.6 +/- 4.3, cough variant asthmatics = 25.6 +/- 3.7, normal subjects = 15.5 +/- 4.3, P < 0.01]. DRS of moderate asthmatics was significantly greater as compared with cough variant asthmatics (geometric mean DRS: mild asthmatics = 30.761, moderate asthma-tics = 59.020, cough variant asthmatics = 19.231, P < 0.05), but there was no difference between the other groups. PC35sGaw was negatively correlated with DRS (r = 0.866, P < 0.001) and with AUC/lg[Cmax] (r = 0.502, P < 0.001). CONCLUSION: Four parameters of DRC obtained after the methacholine challenge represent airway sensitivity and reactivity respectively. The parameters of DRC of asthmatic patients are different from those of normal subjects. The sensitivity is related to the reactivity, but they are not completely parallel with each other.

Adult↗
PubMed2001

[The change of nerve growth factor and brain derived neurotrophic factor in neurons of cerebral cortex of adult rat following local ischemia].

OBJECTIVE: To acquire knowledge about the change of nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF) in neurons of cerebral cortex of adult rat following local ischemia. METHODS: Using specific antiserums of NGF and BDNF by immunohistochemical ABC method. RESULTS: NGF-like and BDNF-like immunoreactions distributed mainly in the neurons of the third and fifth layers in cerebral cortex. After local ischemia, the average gray degrees of NGF and BDNF in neurons of cerebral cortex both decreased on the operated side more than on the un-operated side. CONCLUSION: This experiment demonstrated that the levels of NGF and BDNF in neurons of cerebral cortex following ischemia were upregulated apparently, suggesting that NGF and BDNF may play an important role in the process of neurons' reaction after ischemia.

Animals↗
PubMed2001

[Expression of vascular endothelial growth factor and nm23 as prognostic factors in nasopharyngeal carcinoma].

OBJECTIVE: To evaluate the prognostic significance of vascular endothelial growth factor (VEGF) and nm23 expression for patients with nasopharyngeal carcinoma(NPC). METHODS: From Jan. 1991 to Dec. 1995, 75 NPC patients treated in Department of Radiotherapy & Chemotherapy, Zhongnan Hospital of Wuhan University, with follow-up of more than 4 yrs, were selected to enter this study. Specimens of 75 NPC were studied by immunohistochemical staining for VEGF and nm23. The immunohistochemical data were correlated with development of locoregional failure, distant metastasis and survival. RESULTS: Positive expression of VEGF and negative expression of nm23 were found in 54.7% and 56% of NPC specimens. Positive expression of VEGF and negative expression of nm23 correlated with the development of distant metastasis (P = 0.0181; P = 0.0091) and shorter survival (P = 0.0136; P = 0.0207). No association was observed with locoregional failure. No association was observed between the expression of VEGF and the expression of nm23.Cox proportional hazard model was used to compare the various factors and found the VEGF and nm23 expression were significant prognostic factors for patients with NPC. CONCLUSION: The results of the study show that the VEGF and nm23 expression are significant prognostic factors for patients with NPC and indicate that expression of VEGF and nm23 may be useful in identifying patients who may benefit from systemic chemotherapy or other novel treatment strategies.

Adolescent↗
PubMed2000

Point mutants of c-raf-1 RBD with elevated binding to v-Ha-Ras.

A mutational analysis of the Ras-binding domain (RBD) of c-Raf-1 identified three amino acid positions (Asn(64), Ala(85), and Val(88)) where amino acid substitution with basic residues increases the binding of RBD to recombinant v-Ha-Ras. The greatest increase in binding (6-9-fold) was observed with the A85K-RBD mutant. The elevated binding for the A85K-RBD and V88R-RBD mutants was also detected with Ras expressed in cultured mammalian cells, namely NIH-3T3 and BAF cells. None of the wild type residues in RBD positions Asn(64), Ala(85), and Val(88) have been previously implicated in the interaction with Ras (Block, C., Janknecht, R., Herrmann, C., Nassar, N., and Wittinghofer, A. (1996) Nat. Struct. Biol. 3, 244-251; Nassar, N., Horn, G., Herrmann, C., Scherer, A., McCormick, F., and Wittinghofer, A. (1995) Nature 375, 554-560). The discovery of elevated binding among the mutants in these positions implies that additional RBD residues can be used to generate the Ras. RBD complex. These findings are of particular significance in the design of Ras antagonists based on the RBD prototype. The A85K-RBD mutant can be used to develop an assay for measuring the level of activated Ras in cultured cells; Sepharose-linked A85K-RBD.GST fusion protein served as an activation-specific probe to precipitate Ras.GTP but not Ras.GDP from epidermal growth factor-stimulated cells. A85K-RBD precipitates up to 5-fold more Ras.GTP from mammalian cells than wild type RBD.

Amino Acid Sequence↗
PubMed2000

Expression of zinc-positive cells and terminals in fetal neocortical homografts to adult rat depends on lesion type and rearing conditions.

Zinc-positive neurons and terminals, known to be associated with the glutamatergic projections in the brain, can be demonstrated by the histochemical Timm method and later modifications thereof. The adult rat neocortex contain a uniform lamination of zinc-positive cells with specific projections to, e.g., the striatum. We have previously reported that fetal neocortical grafts implanted in the adult rat neocortex combined with rearing in an enriched environment can improve behavioral functions and reduce the secondary atrophy of thalamus after cortex infarction in adult rats. In order to examine whether the expression of zinc positivity is ontogenetically inherent to neocortical neurons we grafted fetal neocortical tissue to aspiration or ischemic lesions of the frontoparietal neocortex of adult rats, followed by histochemical visualization of the vesicular zinc pool by selenite or sulfide. One further aim of the study was to elucidate to what extent the distribution of zinc-containing neurons and terminals in the grafts depended on rearing under different environmental conditions. The foremost finding of the present study was that the overall density of zinc-containing terminals in fetal cortical transplants placed in brain infarcts of adult spontaneously hypertensive rats is higher when the rats are reared in an enriched environment. Moreover, the presence and expression of zinc-positive neurons and terminals do not seem to be ontogenetically inherent to the cortical neurons as the fetal neocortical grafts placed in aspiration lesions contained no zinc-selenide-positive neurons and few or no zinc-selenide-positive terminals. The presence or expression of zinc-positive cells may thus be induced by ingrowth of fibers and terminals from the host brain as transplants placed in the ischemic lesions expressed both zinc-positive neurons and terminals.

Animals↗
PubMed2000

Lateral biopsies added to the traditional sextant prostate biopsy pattern increases the detection rate of prostate cancer.

Urologists routinely use the systematic sextant needle biopsy technique to detect prostate cancer. However, recent evidence suggests that this technique has a significant sampling error and data based upon whole-mounted step-sectioned radical prostatectomy specimens using a three-dimensional computer-assisted prostate biopsy simulator suggests that an increased detection rate is possible using laterally placed biopsies. The simulated 10-core biopsy pattern (traditional sextant biopsy cores and four laterally placed biopsies in the right and left apex and mid portion of the prostate gland) was shown to be superior to the traditional sextant biopsy. The objective of this pilot study was to confirm the higher prostate cancer detection rate obtained using the 10-core biopsy pattern in patients. We reviewed data on 35 consecutive patients with a pathologic diagnosis of prostate cancer biopsied by a single urologist using the 10-core biopsy pattern. The frequency of positive biopsy was determined for each core. Additionally, the sextant and 10-core prostate biopsy patterns were compared with respect to prostate cancer detection rate. Of the 35 patients diagnosed with prostate cancer, 54.3%(19/35) were diagnosed by the sextant biopsy only. The 10-core pattern resulted in an additional 45.7%(16/35) of patients being diagnosed solely with the laterally placed biopsies. The laterally placed biopsies had the highest frequency of positive biopsies when compared to the sextant cores. In conclusion, biopsy protocols that use laterally placed biopsies based upon a five region anatomical model are superior to the routinely used sextant prostate biopsy pattern. Prostate Cancer and Prostatic Diseases (2000) 3, 43-46

Journal Article↗
PubMed2000

Detailed-term-accounting-approximation simulation of x-ray transmission through laser-produced Al plasmas

An extensive configuration interaction (CI) scheme and the R-matrix method are combined to calculate the x-ray transmission spectrum for high-power laser-produced Al plasmas in local thermodynamic equilibrium by using the detailed-term-accounting (DTA) approximation. All atomic parameters such as state levels and photoabsorption cross sections for different ionization stages are obtained by using the CI and R-matrix method. Special attention is given to the effects of autoionizing resonance broadening on the transmission. A large difference exists between the convergence of the results with and without taking account of autoionizing resonance broadening when the autoionization resonance broadening is the major broadening mechanism. This shows that autoionizing resonance widths of the K-shell excited states have large effects and should be considered to interpret the spectral-resolved transmission.

Journal Article↗
PubMed2000

Mini-review: computational structure-based design of inhibitors that target protein surfaces.

Finding drugs that inhibit protein-protein interactions is usually difficult. While computer-aided design is used widely to facilitate the drug discovery process for protein targets with well-defined binding pockets, its application to the design of inhibitors targeting a protein surface is very limited. In this mini-review we address two aspects of this issue: firstly, we overview the current state of design methodology for inhibitors specifically targeting protein surfaces, and secondly, we briefly outline recent advances in computational methods for structure-based drug design. These methods are closely related to protein docking and protein recognition, the difference being that in ligand design, ligands are built on a fragment-by-fragment basis. A novel scheme of computational combinatorial ligand design developed for the design of inhibitors that interfere with protein-protein interaction is described in detail. Current applications and limitations of this methodology, as well as its future prospects, are discussed.

Combinatorial Chemistry Techniques↗
PubMed2000

3-D computer visualization and interactive prostate biopsy simulation leads to an improved systematic technique for the detection of prostate cancer: clinical correlation.

OBJECTIVES: Urologists routinely use the systematic sextant needle biopsy technique to detect prostate cancer. However, recent evidence suggests that this technique has a significant sampling error. Recent data based upon whole-mounted step-sectioned radical prostatectomy specimens using a 3-D computer assisted prostate biopsy simulator suggests that an increased detection rate is possible using laterally placed biopsies. A new 10-core biopsy pattern was shown to be superior to the traditional sextant biopsy. This pattern includes the traditional sextant biopsy cores and four laterally placed biopsies in the right and left apex and mid portion of the prostate gland. The objective of this study is to confirm the higher prostate cancer detection rate obtained using the 10-core biopsy pattern in a small cohort of patients. METHODS: We retrospectively reviewed 35 consecutive patients with a pathologic diagnosis of prostate cancer biopsied by a single urologist using the 10-core biopsy pattern. The frequency of positive biopsy was determined for each core. Additionally, the sextant and 10-core prostate biopsy patterns were compared with respect to prostate cancer detection rate. RESULTS: Of the 35 patients diagnosed with prostate cancer, 54.3% (19/35) were diagnosed when reviewing the sextant biopsy data only. Review of the 10-core pattern revealed that an additional 45.7% (16/35) of patients were diagnosed solely with the laterally placed biopsies. The laterally placed biopsies had the highest frequency of positive biopsies when compared to the sextant cores. CONCLUSIONS: Our results suggest that biopsy protocols that use laterally placed biopsies based upon a five region anatomical model are superior to the routinely used sextant prostate biopsy pattern. Lateral biopsies in the apex and mid portion of the gland are the most important.

Biopsy, Needle↗
PubMed2000

Software development for registration of digital subtraction angiography (DSA) images in uterine fibroid embolization.

The ISIS Center at Georgetown University Medical Center has developed a comprehensive program for image-guided procedures in the spine. As part of this program, ISIS has developed a software application known as I-SPINE (ISIS's Spine Procedure Imaging Navigation Engine). I-SPINE is a Windows NT application, which is based on the Analyze/AVM libraries. The software architecture follows the Microsoft Foundation Classes (MFC) single document, multiple view paradigm. This has allowed the developers to add new visualization modules to I-SPINE that aid physicians in procedures outside the spine. One such procedure I-SPINE has been expanded for is uterine fibroid embolization. The idea is that by registering and subtracting post-embolization angiographic images from pre-treatment images the resulting image can be used to quantify the embolization effect on the fibroid circulation and predict the treatment response. The I-SPINE digital subtraction angiography (DSA) module allows the interventional radiologist to open a series of pre and post-embolization DSA images that shows the vascular structures of the uterus and the fibroid or fibroids. From these images, the radiologist selects an appropriate image from each series. The selected images are then hand registered using pixel shifting. Once the images are registered, the pixels are subtracted resulting in an image that shows the embolized arteries that were supplying the fibroids.

Angiography, Digital Subtraction↗