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Biomedical subjects

Bo Chen

Publications and source records attributed to Bo Chen.

At least 91 records · Page 5Linked to original sources
PubMed2005

Clinical observation and mechanism study on treatment of senile dementia with Naohuandan.

OBJECTIVE: To observe the therapeutic effect and mechanism of Naohuandan (NHD) in treating senile dementia (SD). METHODS: Clinical study: Fifty-eight patients with SD, whose diagnosis conforms to the Diagnostic Standard of DSM-IV issued by American Association of Psychiatry, were enrolled and randomly assigned into two groups. The 30 patients in the treated group were treated with NHD, 4 capsules each time, 3 times daily. The 28 patients in the control group were treated with Piracetam, 1.6 g each time, 3 times daily. The therapeutic course for both groups was 3 months. The therapeutic efficacy was estimated and compared by comprehensive scores of memory and cognition, scores of Mini-mental State Examination (MMSE) and Activities of Daily Living (ADL). Experimental study: Rats were divided into the control group, the model group and the high-dosage and low-dosage NHD treated groups. The protective effect of NHD on the per-oxidative damage of hippocampal neurons in beta-amyloid protein induced SD model was observed and the related criteria were determined. RESULTS: Clinical study showed that both NHD and Piracetam could improve the clinical symptoms of patients, the two medicines showing insignificant difference in total effective rate. But NHD was better in elevating MMSE score and lowering ADL score in patients than Piracetam (P < 0.05 and P < 0.01). Experimental study showed that (1) 24 and 72 hrs after modeling, the activity of SOD and GSH were lower and the level of MDA higher in the model group than those in the control group (P < 0.05 or P < 0.01). Compared with the model group at the corresponding time points, in the high-dosage NHD group, SOD and GSH were higher, MDA was lower (P < 0.05 or P < 0.01); but in the low-dosage NHD group, SOD at the 72nd hr was higher (P < 0.05) and MDA at 24th and 72nd hrs was lower (P < 0.01). And most of the criteria in the high-dosage NHD group was improved better than that in the low-dosage NHD group. (2) The survival rates of neurons in various groups were not different significantly (P > 0.05) 24 hrs after modeling, but that in the high-dosage NHD group was significantly higher than that in the model group (P < 0.01) and in the low-dosage NHD group 72 hrs after modeling (P < 0.05). CONCLUSION: NHD is an effective Chinese herbal preparation for treatment of SD, and its mechanism is related with its inhibition on peroxidative injury and protection on neurons.

Aged↗
PubMed2005

Application of ultrasonic technique for extracting chlorogenic acid from Eucommia ulmodies Oliv. (E. ulmodies).

An ultrasonic method for the extraction of chlorogenic acid from fresh leaves of Eucommia ulmodies Oliv. was investigated and optimized. The influence of four extraction variables on extraction efficiency of chlorogenic acid was investigated. The optimum extraction conditions found were: 70% aqueous methanol; solvent: sample ratio=20:1 (v/w); extraction time 3 x 30 min. The recovery of chlorogenic acid was studied (HPLC) and the reproducibility of the extraction method was determined. The optimized ultrasonic extraction conditions were applied to extract chlorogenic acid from fresh leaves, fresh bark and dried bark of E. ulmodies and four traditional Chinese medicines. The application of sonication method was shown to be highly efficient in the extraction of chlorogenic acid from E. ulmodies and other Chinese medicines compared with classical methods.

Chlorogenic Acid↗
PubMed2005

Subcellular localization and membrane association of SARS-CoV 3a protein.

SARS-CoV 3a protein was a unique protein of SARS coronavirus (SARS-CoV), which was identified in SARS-CoV infected cells and SARS patients' specimen. Recent studies revealed that 3a could interact specifically with many SARS-CoV structural proteins, such as M, E and S protein. Expressed 3a protein was reported to localize to Golgi complex in SARS-CoV infected cells. In this study, it was shown that 3a protein was mainly located in Golgi apparatus with different tags at N- or C-terminus. The localization pattern was similar in different transfected cells. With the assay of truncated 3a protein, it was shown that 3a might contain three transmembrane regions, and the second or third region was properly responsible for Golgi localization. By ultra-centrifugation experiment with different extraction buffers, it was confirmed that 3a was an integral membrane protein and embedded in the phospholipid bilayer. Immunofluorescence assay indicated that 3a was co-localized with M protein in Golgi complex in co-transfected cells. These results provide a new insight for further study of the 3a protein on the pathogenesis of SARS-CoV.

Animals↗
PubMed2005

Relationship between leukocyte count and angiographical characteristics of coronary atherosclerosis.

AIM: To explore the relationship between differential leucocyte count and coronary atherosclerosis. METHODS: The study population consisted of 507 consecutive patients (376 male and 131 female) who underwent coronary angiography for suspected or known coronary atherosclerosis. The patients' smoking and drinking habits were investigated, and anthropometric measurements, serum measurements, and hematological measurements were conducted for every patient. The severity of coronary atherosclerosis was defined by using Gensini's score system. One-way ANOVA, Spearman's correlation analysis, and multivariate stepwise linear regression analysis were employed to explore the relationship between differential leucocyte count and coronary atherosclerosis. RESULTS: One-way ANOVA indicated that the diastolic blood pressure, glucose, urea, creatinine, leukocyte count, neutrophil count, monocyte count, hemoglobin, and platelet count differed among the groups according to Gensini's score, the tertile values of which were used as cutoff points. Spearman's correlation analysis suggested that Gensini's score was significantly correlated with age, diastolic blood pressure, glucose, urea, creatinine, leukocyte count, neutrophil count, monocyte count, hemoglobin, and erythrocyte count, respectively. Multivariate stepwise linear regression analysis show that neutrophil count (beta=0.247, P=0.000), age (beta=0.141, P=0.001), glucose (beta=0.173, P=0.000), creatinine (beta=0.088, P=0.063), hemoglobin (beta=-0.168, P=0.013) and sex (men were coded as 1 and women were coded as 2; beta=-0.121, P=0.012) were significantly independently associated with the Gensini's score. CONCLUSION: The independent association of neutrophil count with the angiographical characteristics of coronary atherosclerosis, as estimated by Gensini's score, strongly suggests that granulocytosis may play a role in the development of coronary atherosclerosis.

Age Factors↗
PubMed2005

[Development of soft X-ray and vacuum ultraviolet spectrum sources].

The soft X-ray and vacuum ultraviolet sources developed in CIOMP are presented. The wall-stabilized argon arc source with spectrum stability and repeatability of +/-0.3% is applied to the calibration of spectrum intensity distribution of the vacuum ultraviolet instruments as an absolute standard source. The Penning source, duobplasma source and hollow cathode source are able to produce atomic and ionic line spectra as a wavelength standard source, which covers a few nanometers to several tens nanometers with spectrum radiation stability and repeatability of +/-1.0%. In particular, the low debris laser produced plasma source with liquid aerosol spray target recently developed can emit stronger soft X-ray for soft X-ray lithography and metrology, which has a transfer efficiency as high as 0.75%/2pi x sr/2% bandwidth.

Aluminum↗
PubMed2005

[Soft X-ray reflectometer with laser produced plasma source].

A soft X-ray reflectometor with laser-produced plasma source developed in the authorial lab is presented for the measurements of efficiencies of gratings, transmission of filter and reflectance of multilayer coatings. The reflectometer is composed of a soft X-ray laser-produced plasma source, a grazing incidence monochromator with a constant deviation angle, a vacuum chamber, a sample table, a photo-electronic unit and a computer controlling unit. The working wavelength is from 8 to 30 nm and the maximum sample size is 130 mm long by 120 mm wide by 120 mm high. In order to test the performances of the reflectometer, the reflectivity of multilayer coatings was obtained by using this device. The measured results agree well with the theoretical calculation. The reproducibility of measured reflectance is +/-0.6%.

Algorithms↗
PubMed2005

[Tropism of adult liver stem cells toward hepatocellular carcinoma cells in vitro].

OBJECTIVE: To explore the biological behavior of adult liver stem cells in a co-cultured system of them with hepatocellular carcinoma (HCC) cells without direct contact between the two kinds of cells. METHODS: WB-F344, a kind of rat adult liver stem cell, and rat embryonic fibroblasts (REF) from a primary culture were engineered to express enhanced green fluorescent protein (EGFP) by recombinant adenoviral-mediated methods. Two kinds of cells marked with EGFP were established, namely WB-EGFP and REF-EGFP. After the HCC cells grew to 40%-60% confluence in the culture dish with a 10-mm cell-free area, a similar number of WB-EGFP and REF-EGFP were placed in the blank areas respectively. Then, we constantly studied the movement behavior of WB-EGFP in the co-culture system with HCC cells. RESULTS: The results showed that WB-EGFP cells migrated to the area of HCC cells slowly. Their appearance was found not only when WB-EGFP cells were seeded into the cell-free area at the center of the dish, but also when seeded into the blank area at the extreme edge of the plate. This trait was not observed in the co-cultured system of REF-EGFP and HCC cells, and most REF-EGFP were still localized in their initial area after 72 hours of incubation. CONCLUSIONS: The results mean that adult liver stem cells have a biological behavior of selective tropism toward HCC cells in vitro, and suggest a possibility of using migratory liver stem cells as a delivery vehicle for gene therapy for HCC.

Adenoviridae↗
PubMed2005

Protective effects of blocking renin-angiotensin system on the progression of renal injury in glomerulosclerosis.

To investigate the protective effects of blocking rennin-angiotensin system (RAS) on the progression of renal injury in glomerulosclerosis, a glomerulosclerosis model was made for SD rats by unilateral nephrectomy and being injected with Adriamycin into caudal vein. The rats with glomerulosclerosis were randomly divided as ten per group into those without further treatment (group D) and those treated with Benazepril (group DB), Losartan (group DL), or sham-operation (group C), respectively. After 6 weeks of administration of Benazepril or Losartan, the mRNA expressions of TGF-beta1, Col IV, Fn, ET-1 and iNOS in renal cortex were measured by RT-PCR. Besides, the expressions of TGF-beta1, ET-1 and iNOS at protein level were detected by Western blotting and the concentrations of Col IV and Fn were analyzed with immunohistochemistry respectively. Results showed that the rats in group D appeared as obvious proteinuria, hypoalbuminemia and hypercholesterolemia, which had a significant difference compared with group C (p < 0.05), and most of their mesangiums were detected with cellular proliferation and significant increasing for extracellular matrix. Renal cortex TGF-beta1, Col IV, Fn, ET-1 and iNOS in rats of group D were increased by 3.59, 2.57, 2.21, 2.58 and 3.28 times at mRNA level, and by 2.60, 1.40, 0.75, 1.83 and 2.15 times at protein level, respectively, compared with group C. When the animals were treated with Benazepril (group DB) or Losartan (group DL), however, the biochemical and pathological damages were significantly recovered, and protein expressions of TGF-beta1, Col IV, Fn, ET-1 and iNOS were also significantly diminished (p < 0.05). This study suggested that blocking RAS using Benazepril or Losartan can have protective effects on the renal injury in glomerulosclerosis by down-regulating the expressions of TGF-beta1, Col IV, Fn, ET-1 and iNOS.

Angiotensin II Type 1 Receptor Blockers↗
PubMed2005

[Determination of sildenafil and vardenafil in human plasma by high performance liquid chromatography coupled with liquid-liquid-liquid microextraction].

High performance liquid chromatography coupled with liquid-liquid-liquid microextraction was developed for the simultaneous determination of sildenafil and vardenafil in human plasma. The effects of extraction solvent, the volume of organic solvent, dropsize of acceptor phase, stirring rate and extraction time on the enrichment factors of analytes were investigated. The optimized experimental conditions, 300 microL toluene as the organic phase, 2 microL 0.2 mol/L HCl as the acceptor phase, 600 r/min of the stirring rate, and 40 min of the extraction time, were gotten. Under these conditions, high enrichment factors were obtained. The linear range of studied analytes was from 5 microg/L to 1.0 mg/L. The relative standard deviation was lower than 5%. The limits of detection were 1 microg/L for sildenafil and 0.5 microg/L for vardenafil at signal-to-noise ratio of 3. The method with little solvent consumption may provide high analyte preconcentration and excellent sample clean-up, and it is a sensitive and suitable method for simultaneous determination of the above two substances in human plasma.

Chemical Fractionation↗
PubMed2005

[Comparison on urinary 1-hydroxypyrene concentrations between coke oven workers and non-occupational exposed individuals].

OBJECTIVE: To compare the urinary 1-hydroxypyrene (1-OHP) concentrations between coke oven workers and non-occupational exposed individuals and to investigate the possible impact factors. METHODS: Spot end-of-shift urine samples were collected in 265 coke oven workers and spot morning urine samples in 226 non-occupational exposed individuals. External exposure levels and possible confounding factors were assessed by environmental polycyclic aromatic hydrocarbons (PAH) monitoring and uniform questionnaire, and the urinary 1-OHP concentrations determined by high performance liquid chromatography (HPLC), were used to compare the different urinary 1-OHP levels between different research populations and to explore the effects of several factors such as external exposure levels, smoking habits, alcohol consumptions, age and body mass index (BMI). RESULTS: The urinary 1-OHP concentrations in coke oven workers were significantly higher than those in non-occupational exposed individuals (13.49, 6.56, 1.38 and 0.35 micromol/mol creatinine for topside workers, side-oven workers, bottom side workers and references, respectively, P < 0.001; the same trends for the percentage of the level over 2.3 micromol/mol creatinine: 94.81%, 84.73%, 35.09% and 0.88%, P < 0.001). The control individuals who smoked over 20 cigarettes per day possessed higher urinary 1-OHP concentrations than the non-smokers (adjusted geometric mean: 0.47 and 0.31 micromol/mol creatinine, respectively, P < 0.05). Alcohol drinking references possessed lower urinary 1-OHP levels than the non-drinkers (adjusted geometric mean: 0.33 and 0.47 micromol/mol creatinine, respectively, P < 0.05). CONCLUSION: Coke oven workers should be exposed to a high level of urinary 1-OHP, especially for topside workers and side-oven workers. Background urinary 1-OHP levels in non-occupational exposed individuals should be related to smoking habits and alcohol consumptions.

Air Pollutants, Occupational↗
PubMed2005

[Study of determination method for lead and cadmium in the semen and liquor follicle of genetic fluid].

Lead and Cadium as the key elements influencing human genetic health were selectively determined in the present paper. In the area of metal elements determination in body fluid, most samples used in the study are blood, plasma and saliva. No literature about genetic fluid determination has been found so far. In the present paper the preparation of samples, volume of samples, and determination parameters were investigated. An easy reliable method of determining lead and cadium in semen and liquor follicle is established. The recoveries of lead are 99.0%-118% and the recoveries of cadium are 96.3%-109%. The determination limit of lead is 0.8 microg x L(-1) and the determination limit of cadium is 0.05 microg x L(-1). The relative standard deviations (RSD)(n = 5) are 3.74%-8.54%.

Cadmium↗
PubMed2005

[Simulation of UV spectra from the wake of a stony meteor in the upper atmosphere].

For stony meteors thrusting through a region with an altitude between 100-90 km in the upper atmosphere at different initial geocentric velocities, the effective temperatures are calculated based on Sparrow's particle-collision theory. Assuming different mixture ratios, particle number densities of certain dominant components that might exist in the wake of a stony meteor at a velocity of 72 km x s(-1) are given. Using a large-scale spectral synthesis code called Cloudy, UV radiation within the 240-400 nm band of the wake of such a meteor is simulated, and relative intensities of several expected strong emission lines are predicted. Comparison shows that our prediction of the spectrum of a meteor wake, which has an effective temperature of 5 680 K and a fractional vapor pressure of 0.1 Pa, is fairly close to the observational results.

English Abstract↗
PubMed2004

Cutting edge: bone morphogenetic protein antagonists Drm/Gremlin and Dan interact with Slits and act as negative regulators of monocyte chemotaxis.

Drm/Gremlin and Dan, two homologous secreted antagonists of bone morphogenic proteins, have been shown to regulate early development, tumorigenesis, and renal pathophysiology. In this study, we report that Drm and Dan physically and functionally interact with Slit1 and Slit2 proteins. Drm binding to Slits depends on its glycosylation and is not interfered with by bone morphogenic proteins. Importantly, Drm and Dan function as inhibitors for monocyte migration induced by stromal cell-derived factor 1alpha (SDF-1alpha) or fMLP. The inhibition of SDF-1alpha-induced monocyte chemotaxis by Dan is not due to blocking the binding of SDF-1alpha to its receptor. Thus, the results identify that Drm and Dan can interact with Slit proteins and act as inhibitors of monocyte chemotaxis, demonstrating a previously unidentified biological role for these proteins.

Animals↗
PubMed2004

Effect of mitogen-activated protein kinase signal transduction pathway on multidrug resistance induced by vincristine in gastric cancer cell line MGC803.

AIM: To investigate the correlation between mitogen-activated protein kinase (MAPK) signal transduction pathway and multidrug resistance (MDR) in MGC803 cells. METHODS: Western blot was used to analyze the expression of MDR associated gene in transient vincristine (VCR) induced MGC803 cells, which were treated with or without the specific inhibitor of MAPK, PD098059. Morphologic analysis of the cells treated by VCR with or without PD098059 was determined by Wright-Giemsa staining. The cell cycle analysis was performed by using flow cytometric assay and the drug sensitivity of MGC803 cells which were exposed to VCR with or without PD098059 was tested by using MTT assay. RESULTS: Transient exposure to VCR induced P-gp but not MRP1 or GST-pi expression in MGC803 cells and the expression of P-gp was inhibited by PD098059. Apoptotic bodies were found in the cells treated with VCR or VCR+PD098059. FCM results indicated that more MGC803 cells showed apoptotic phenotype when treated by VCR and PD098059 (rate: 31.23%) than treated by VCR only (rate: 18.42%) (P<0.05). The IC(50) (284+/-13.2 mug/L) of MGC803 cells pretreated with VCR was 2.24-fold as that of negative control group (127+/-17.6 mug/L) and 1.48-fold as that of the group treated with PD098059 (191+/-27.9 mug/L). CONCLUSION: This study shows that the expression of P-gp can be induced by transient exposure to VCR and this induction can be prevented by PD098059, which can block the activity of MAPK. MAPK signal transduction pathway may play some roles in modulating MDR1 expression in gastric cancer.

Antineoplastic Agents, Phytogenic↗
PubMed2004

Simultaneous analysis of theanine, chlorogenic acid, purine alkaloids and catechins in tea samples with the help of multi-dimension information of on-line high performance liquid chromatography/electrospray-mass spectrometry.

A reverse phase high performance liquid chromatography (RP-HPLC) separation coupled with photo diode array detection (DAD) and electrospray ionization mass spectrometry (ESI-MS) detection was established for the analyzing of multiple bioactive compounds in tea and tea extracts. Theanine, chlorogenic acid, purine alkaloids and catechins were identified with authentic standard compounds and with MS-spectra. The content of theanine and catechins was measured by employing DAD and caffeine, chlorogenic acid, theobromine and theopylline by protonated molecular ion on selective ion recording (SIR) mode. The unity of LC/ESI-MS provides more qualitative and quantitative information comparing with general HPLC in the analysis of multi-components in tea, and complex extraction or sample pretreatment is unnecessary. The chromatogram acquired by using this method can be used as a bioactive components fingerprint for the quality control of tea and its extracts. With the help of multi-dimension information of HPLC-DAD-ESIMS, the compounds owning different chemical structure such as amino acid, catechins, etc. in tea and its extracts could be identified and determined in one run successfully.

Alkaloids↗
PubMed2004

Cascaded wavelength conversions based on sum-frequency generation and difference-frequency generation.

A novel wavelength conversion scheme based on cascaded sum-frequency generation (SFG) and difference-frequency generation (DFG) is proposed and demonstrated in a MgO-doped LiNbO3 quasi-phase-matched waveguide. In this scheme, two pump wavelengths are set outside the communication band. It is shown that the same conversion efficiency can be achieved by use of two pump sources with lower output power (P1, P2) in this scheme compared with the conventional cascaded wavelength conversion technique based on second-harmonic generation and DFG with a single higher-power pump beam (P = P1 + P2) that is due to the use of a larger SFG nonlinear coefficient. The results significantly influence the selection of a suitable nonlinear interaction scheme for practical applications.

Journal Article↗
PubMed2004

Identification of a novel C1q family member in color crucian carp (Carassius auratus) ovary.

Potential roles of C1q/tumor necrosis factor (TNF) superfamily proteins have been observed in vertebrate oogenesis and oocyte maturation, but no ovary-specific member has been identified so far. In this study, we have cloned and identified a novel member of C1q family with a C1q domain in the C-terminal from fully grown oocyte cDNA library of color crucian carp and demonstrated that the gene might be specifically expressed in ovary and therefore designated as Carassius auratus ovary-specific C1q-like factor, CaOC1q-like factor. It encodes a 213 amino acid protein with a 17 amino acid signal peptide. There is only one protein band of about 24.5 kDa in the extracts from phase I to phase IV oocytes, but two positive protein bands are detected in the extracts of mature eggs and fertilized eggs. Furthermore, the mobility shift of the smaller target protein band cannot be eliminated by phosphatase treatment, but the larger protein band increases its mobility on the gel after phosphatase treatment, suggesting that the larger protein might be a phosphorylated form. Immunofluorescence localization indicates that the CaOC1q-like proteins localize in cytoplasm, cytoplasm membrane and egg envelope of the oocytes at cortical granule stage and vitellogenesis stage, whereas they were compressed to cytoplasm margin in ovulated mature eggs and discharged into perivitelline space between cytoplasm membrane and egg envelope after egg fertilization. Further studies on distribution and translocation mechanism of the CaOC1q-like factor will be benefit to elucidate the unique function in oogenesis, oocyte maturation and egg fertilization.

Amino Acid Sequence↗