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Biomedical subjects

Jun Chen

Publications and source records attributed to Jun Chen.

At least 325 records · Page 18Linked to original sources
PubMed2003

[Evaluation on control efficacy of Scleroderma guani against borer].

Scleroderma guani is an ectoparasitic insect of some borer, especially the larvae or the pupae of longicorn. In Pingyi county of Shandong province, Scleroderma guani was found when it naturally parasitized Xylotrechus grayii in 1980. Passed more than ten years systematic studies, it has been found that this harpactophayeous insect has great boring ability and can be parasitize many hosts. In the fields to release Scleroderma guani for controlling Xylotrechus grayii, Phytoecia rufiventris, Anoplophora glabripennis etc. have achieved good results and kept steady effects. Therefore, spreading Scleroderma guani to control the borer is a new technology in sustaining plant protection.

Animals↗
PubMed2003

[The relaxation effects of tetrandrine on the corpus cavernosum tissue of rabbit in vitro].

OBJECTIVES: To study the relaxation effects of tetrandrine on the corpus cavernosum tissue of rabbit in vitro. METHODS: 1. The fluctuation of the dose-response relaxation curves for the contraction of KCl induced by tetrandrine was observed with isolated rabbit corpus cavernosum tissue. 2. Isolated strips of rabbit corpus cavernosum tissue were precontracted with 10 mumol/L phenylephrine(PE). Relaxation in response to cumulative doses of tetrandrine was determined in the absence and presence of nitric oxide synthase inhibitor (L-NNA) and soluble guanylate cyclase inhibitor (methylthioninium). RESULTS: 1. The dose-response curves of KCl were shifted to the right nonparallelly, and the maximal responses were depressed to (73.0 +/- 3.8)% and (41.5 +/- 3.4)%, respectively, in the presence of tetrandrine(10 mumol/L, 30 mumol/L). 2. On rabbit cavernosal muscle stripes precontracted with PE(10 mumol/L), increasing concentrations of tetrandrine (1 mumol/L, 10 mumol/L, 30 mumol/L and 100 mumol/L) showed dose dependent relaxation [(6.0 +/- 1.4)%, (21.3 +/- 2.2)%, (47.4 +/- 3.3)%, and (68.1 +/- 3.6)%, P < 0.01]. However, in the meantime, it was found that these relaxation effects were not affected by the presence of L-NNA and methylthioninium (P > 0.05). CONCLUSIONS: Tetrandrine was effective in relaxing rabbit corpus cavernosum tissue in vitro in a dose-dependent style. The mechanism might be related with its blocking effect on calcium channel, but not the NO-cGMP passage.

Alkaloids↗
PubMed2003

[A preliminary study of endoscopic ultrasonography in the preoperative staging of early gastric carcinoma].

OBJECTIVE: To study the clinical value of endoscopic ultrasonography (EUS) in the preoperative staging of early gastric carcinoma. METHODS: EUS was performed in 149 gastric carcinoma patients proved by biopsy (including 33 patients with early gastric cancer), of which the results were compared with postoperative pathologic findings. RESULTS: The accuracy of EUS in determining the T stage of gastric carcinoma was 80.3% (T1 81.8%, T2 70.4%, T3 88.9%, T4 71.4%). The accuracy of EUS in differentiating early gastric carcinoma from advanced ones was 95.1%, and the accuracy of EUS in differentiating mucosal cancer from submucosal cancer was only 63.6%. The diagnostic accuracy of EUS for mucosal and submucosal cancer was 52.9% and 75%, with positive predictive value of 90% and 70.6%, respectively. The accuracy of invasion depth of EUS for the bulging and flat type of early gastric carcinoma was 100%, whereas the accuracy was only 58.6% for the depressed type. The accuracy of invasion depth of the differentiated and undifferentiated early cancer was 71.4%and 57.9%, without any significant difference (P > 0.05). The accuracy of invasion depth of EUS for early gastric carcinoma decreased as tumor size increased. The diagnostic accuracy of lymph node status of early gastric carcinoma by EUS was 90.9%, and the sensitivity and specificity of lymph node metastasis was 66.7% and 96.3%, respectively. CONCLUSION: The clinical value of endoscopic ultrasonography in the preoperative staging of early gastric carcinoma is relatively high.

Adenocarcinoma↗
PubMed2003

[Quantitative detection of hepatitis B virus by fluorescence quantitative PCR and its clinical value].

OBJECTIVE: To study the relationship between the serum contents of HBV DNA copies and the HBV serum index of immunology and the degree of hepatocyte injury in patients with HBV hepatitis. METHODS: The contents of HBV DNA copies were detected by fluorescence quantitative PCR (FQ-PCR), and the HBV serum index of immunology by ELISA. RESULTS: The contents of HBV DNA copies had a significant difference between HBeAg (+)/anti-HBe (-) group (42 patients) and HBeAg (-)/anti-HBe (+) group (57 patients) or HBeAg (-)/anti-HBe (-) group(11 patients) (P < 0.05), while there was no significant difference between HBeAg (-)/anti-HBe (+) group and HBeAg (-)/anti-HBe (-) group(P > 0.05). The contents of HBV DNA copies had no correlation with the severe degree of hepatocyte injury(P > 0.05). CONCLUSION: Anti-HBe is not the terminal sign of HBV replication. The severe degree of hepatocyte injury has not a direct correlation with the contents of HBV DNA copies.

Adolescent↗
PubMed2003

[Effects of tetramethylpyrazine on cytosolic free calcium concentration in penis corpus cavernsum smooth muscle cells in rabbits].

OBJECTIVE: To study the effects of Chinese medicine tetramethylpyrazine (TMP) on intracellular free calcium ([Ca2+]i) in cultured penis corpus cavernosum smooth muscle cell (PCSMC) in rabbits. METHODS: By using laser scanning confocal microscope (LSCM), the [Ca2+]i fluorescence signal changes was investigated in cultured PCSMC loaded with Ca2+ indicator Fluo-3/AM and divided into potassium chloride(KCl) group and norepinephrine (NE) group. Compared with verapamil (Ver), the effects of TMP was observed in different concentrations on [Ca2+]i increase induced by high potassium and NE. RESULTS: TMP had no obvious effect on resting PCSMC [Ca2+]i. It was found that 1, 10, 100 mumol/L TMP significantly inhibited [Ca2+]i increase induced by high potassium-depolarization. The peak inhibition rates were (38.6 +/- 3.0)%, (44.1 +/- 2.4)% and (53.7 +/- 4.1)% respectively. TMP could also inhibit cytosolic calcium pool release induced by 1 mumol/L NE. The peak inhibition rates were (13.9 +/- 2.7)%, (21.2 +/- 1.9)% and (29.5 +/- 3.6)% respectively. CONCLUSIONS: TMP can inhibit rabbit PCSMC [Ca2+]i significantly by suppressing voltage-dependent calcium channel and cytosolic calcium pool release. The effect, similar to Ver, signifies the important mechanism of erectile dysfunction (ED) therapy.

Animals↗
PubMed2003

[Investigation on occurrence of lycium barbarum pests and its natural enemies at Ningxia].

OBJECTIVE: To provide the scientific basis for controlling Lycium barbarum pests. METHODS: The kinds and number of the pests and its natural enemies were investigated at fixed plants. RESULT: There were 38 species of Lycium barbarum pests and 23 species of natural enemies, the occurrence of them were closely related. CONCLUSION: Natural enemies can control Aphis and Paratrioza effectively.

Animals↗
PubMed2003

[Studies on supercritical CO2 fluid extraction for ginkgolic acids in the epicarp of Ginkgo biloba].

The technology of supercritical CO2 fluid extraction for ginkgolic acids in the epicarp of Ginkgo biloba L. was studied. The effect of pressure, temperature and extraction time on the yield of the ginkgolic acids was explored. The optimum conditions for supercritical CO2 fluid extraction was 30 MPa, 45 degrees C, extraction time 6 h and the flow rate of CO2 2L/min. The ginkgolic acids were determined by HPLC. Supercritical CO2 fluid extraction exceled the traditional solvent extraction in high yield, high purification and easy operation.

Carbon Dioxide↗
PubMed2003

[Study on purification of glycyrrhizic acid with macroporous adsorption resin].

OBJECTIVE: To study the adsorption and desorption behavior of macroporous adsorbption resin AB-8 for glycyrrhizic acid and its effect factors. METHODS: The optimum purification conditions were investigated by high performance liquid chromatography and the orthogonal experiments. RESULTS: The optimum conditions were as follows: the flow rate at 1 ml/min, pH at 6.4-7.4 and the solution concentration at 10 mg/ml. CONCLUSION: AB-8 had a high adsorption capacity for glycyrrizic acid and elution was easy.

Adsorption↗
PubMed2003

Phospholipid scramblase 3 controls mitochondrial structure, function, and apoptotic response.

Phospholipid scramblase 3 (PLS3) is a newly recognized member of a family of proteins responsible for phospholipid translocation between two lipid compartments. To study PLS3 function in mitochondria, we disrupted its conserved calcium-binding motif yielding an inactive mutant PLS3(F258V). Cells transfected with PLS3(F258V) exhibited reduced proliferative capacity. Mitochondrial analysis revealed that PLS3(F258V)-expressing cells have decreased mitochondrial mass shown by lower cytochrome c and cardiolipin (CL) content, poor mitochondrial respiration, and reduced oxygen consumption and intracellular ATP; whereas wild-type PLS3-transfected cells exhibit increased mitochondrial mass and enhanced respiration. Electron microscopic examination revealed that the mitochondria in PLS3(F258V)-expressing cells have densely packed cristae and are fewer in number and larger than those in control cells. The abnormal mitochondrial metabolism and structure in PLS3(F258V)-expressing cells were associated with decreased sensitivity to UV- and tBid-induced apoptosis and diminished translocation of CL to the mitochondrial outer membrane. In contrast, wild-type PLS3-transfected cells displayed increased sensitivity to apoptosis and enhanced CL translocation. These studies identify PLS3 as a critical regulator of mitochondrial structure and respiration, and CL transport in apoptosis.

Apoptosis↗
PubMed2003

[Isolation and HPLC analysis of ginkgolic acid].

OBJECTIVE: To isolate ginkgolic acids (GA) from exopleura of Ginkgo biloba and to analyse GA. METHODS: GA were ultrasonic-extracted from exopleura of Ginkgo biloba with petroleum ether, and purified by silica gel column chromatography. The content of GA in sample was determined by HPLC with methanol-3% acetic acid (90:10) as mobile phase at a flow rate of 1 ml/min. UV detection wavelength was set at 310 nm. A HiQ sil C18 column was used at 40 degrees C in analysis. RESULTS: A good linearity was obtained in the range of 1.144-5.720 micrograms (r = 0.9978) for GA. The average recovery of GA was 97.50% with RSD of 1.70%. CONCLUSION: The method may be employed to prepare GA from exopleura of Ginkgo biloba. The analysis method for GA is accurate and reliable, and can be used for determination of GA in sample.

Chromatography, High Pressure Liquid↗
PubMed2003

[Progress on industrial ecological studies of dry-cleaning process].

The safety assurance of dry cleaning solvent and rational residue criteria of volatile hazardous organic compounds in clothes are vital to clean production and green service in dry cleaning industry. Therefore, the environmental behavior of the enterprises should be regulated and assurance to the human health and the environment through the combination of environmental technologies and economic instruments. Progress on industrial ecological studies of dry-cleaning process was reviewed and the protective strategies and approaches of environmental safety technologies to the sustainable development of dry cleaning were put forward in this paper.

Environmental Health↗
PubMed2003

[Advances in studies of Chinese herbs for improving relaxability of corporal smooth muscle].

Erectile dysfunction (ED) is a commonly and frequently encountered disease among middle-aged and old males. The traditional Chinese medicine has a long history of medical treatment for ED has been focusing too much on clinical experience researches, without obtaining sufficient evidence for the curative effect of related traditional medicines. Recently, with important breakthroughs the researches on the molecular biochemical mechanisms of erection, sildenafil(Viagra), a phosphodiesterase type 5 (PDE5) inhibitor, has been developed, and exciting progress achieved in the treatment of ED with Chinese herbal medicine and the presentation of the pharmacological mechanism. This article presents an overview on recent advances in the studies of ED treatment with traditional Chinese medicine.

Animals↗
PubMed2003

[Effects and holding time of hyperbaric oxygen on human severe periodontitis].

OBJECTIVE: This paper studied the therapeutic effects and holding time of hyperbaric oxygen (HBO) on human severe periodontitis. METHODS: 30 cases with periodontitis were selected and randomly divided into 2 groups, i.e. the HBO group and control group. For HBO group, they were exposed to a pressure of 0.25 MPa. For control group, they were rinsed with gargle. Gingival indices (GI), sulcus bleeding indices (SBI), plaque index (PLI), probing depth (PD), attachment loss (AL) and gingival crevicular fluid (GCF) were measured during both the first and last clinical visits, and 1 year after HBO therapy. The gingival blood flow (GBF) were measured by Laser Doppler Flowmeter. RESULTS: HBO can decrease GI of patients with periodontitis by 1.1 decrease SBI by 1.2, lower PD and AL by 0.7 mm, decrease the volume of GCF by 2.0, and significant differences could be seen in the above indices between pre and post HBO therapy. The GBF had a 1.8 folds increase after HBO exposure. GI and SBI one year after HBO therapy were larger than that of the time after HBO therapy. There were no significant differences in the PLI, PD, AL, GCF, GBF between post HBO therapy and 1 year after HBO therapy. CONCLUSION: HBO had good therapeutic effects on human severe periodontitis, the effects can keep more than 1 year.

Adult↗
PubMed2003

[Determination of ginkgolic acids in Ginkgo biloba extract and its preparations by high performance liquid chromatography].

AIM: To establish a high performance liquid chromatographic method for determination of ginkgolic acids in Ginkgo biloba extract and its preparations. METHODS: Ginkgo biloba extract and its preparations were extracted with petroleum ether in Soxhlet apparatus, and then concentrated under vacuum. The ginkgolic acids were determined directly by HPLC, and identified by LC/DAD/ESI/MS. The chromatographic column was Inertsil ODS-2; the mobile phase was methanol-3% aqueous acetic acid(92:8); the flow rate was 1.0 mL.min-1; the column temperature was 40 degrees C; the detection wavelength was 310 nm. RESULTS: There were six kinds of ginkgolic acid (C13:0, C15:1, C17:2, C15:0, C17:1 and an unknown compound C17:3 tentatively) in the Ginkgo biloba extract. The relative percentage content of ginkgolic acids C13:0, C15:1 and C17:1 was above 94%. The content of ginkgolic acids in Ginkgo biloba extract containing high content ginkgolic acids was 1.12%, and RSD was 2.4% (n = 5). The content of ginkgolic acids in one kind of EGb preparations (tablet) was 49.2 micrograms.g-1, and RSD was 4.3% (n = 5). The average recovery was 98.2%, RSD was 2.6% (n = 5). CONCLUSION: The method is accurate, fast, simple, and can be used for determination of ginkgolic acids in Ginkgo biloba extract and its preparations.

Chromatography, High Pressure Liquid↗
PubMed2003

Pharmacokinetics of sibutramine hydrochloride in Chinese healthy volunteers.

AIM: To evaluate the pharmacokinetic profiles of the pharmacologically active primary amine metabolite of sibutramine, N-di-desmethyl sibutramine (BTS 54505) in Chinese origin. METHODS: According to a randomized cross-over design, a single oral dose of 20 mg of sibutramine hydrochloride capsule was given to 20 healthy Chinese young volunteers. After dosing, serial blood samples were collected for a period of 72 h. BTS 54505 concentration in plasma was analyzed by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. RESULTS: Various pharmacokinetic parameters including AUC0-t, AUC0-infinity, Cmax, Tmax, T1/2, Kelm and MRT were determined for both test and reference capsules and found to be in good agreement with literature values. CONCLUSION: The test and reference sibutramine capsules were bioequivalent.

Administration, Oral↗
PubMed2003

[Presearch on preventing the medicinal plant diseases with Trichoderma harzianum preparation].

OBJECTIVE: To control the medicinal plant diseases with the preparation of Trichoderma harzianum. METHOD: Antagonistic action of the preparation to the pathogens of the medicinal plants in vitro, and controling effects of the preparation on these diseases in greenhouse and in the field were tested. RESULT: The test in vitro showed that Trichoderma harzianum, used as a biocontrol factor, had stronger antagonistic action to Fusarium equiseti, Sclerotinia sp. and Rhizoctonia solani which were the medicinal plant pathogens of Astragalus membranaceus, Glehnia littoralis and Panax quinquefolium respectively. Biological controling effects on sclerotium root rot of Glehnia littoralis were 83.6% and 72.5% respectively in greenhouse and in the field with the preparation of Trichoderma harzianum. And controling effects on root rot of Astragalus membranaceus and seedling damping-off of Panax quinquefolium were 80% and 60% respectively in the field. The dosage of the preparation used in the field was 10 g.m-2. CONCLUSION: The preparation of Trichoderma harzianum can be used as a substitute for such chemicals as Carbendazim. Using the preparation to control medicinal plant diseases provides a technical safeguard for the good agricultural practice of medicinal plants.

Apiaceae↗