1.Effect and mechanism of arsenic trioxide on lymphangiogenesis of transplan tation tumor model for human breast infiltrating duct carcinoma in nude mice
Journal of Chongqing Medical University 2007;0(09):-
Objective:To investigate the antitumor lymphangiogenesis activity and mechanism of arsenic trioxide on transplantation tumor model for human breast infiltrating duct carcinoma in nude mice. Methods: The mice bearing tumor were randomly divided into 4 groups-negative control, positive control, experiment group 1 and 2, which were injected into a tail vein with sodium chloride, 5-Fluorouracil(30 mg/kg) and arsenic trioxide (1.5 mg/kg or 3.0 mg/kg) for 7 days respectively. The intratumoral microlymphatics density (MLD) and expressions of vascular endothelial growth factor C(VEGF-C), nuclear factor kappa-B P65,and Her2 protein were evaluated by immunohistochmistry methods. Reverse transcription-PCR was used to detect the expression of VEGF-C mRNA. Results: The tumors in arsenic trioxide groups showed significantly lower MLD than those in control groups(P
2.Morphological characteristics of lymphatics in transplantation tumor model of human breast infiltrating duct carcinoma in nude mice
Journal of Chongqing Medical University 1986;0(03):-
Objective: To observe the morphological characteristics of lymphatics and to investigate the intratumoral lymphangiogenesis in transplantation tumor model of human breast infiltrating duct carcinoma in nude mice.Methods: Small slices of human breast carcinoma tissue were transplanted into 5 nude mice to establish implanted tumor model.HE staining was used to observe the characteristics of the transplantation tumors.Vascular endothelial growth factor-3(VEGFR-3) label staining was performed to observe lymphatics,and ultrastructure of lymphatics was observed with transmission electron microscope(TEM).Results: Tumors were viable in a11 the mice,and grew up to about 0.6~0.8 centimeters in diameter after 52 days when specimen was collected.Under light microscope,lymphatics were found in all the tumors,and were located seemingly much more in periphery than in the center of the tumors.Under TEM some characteristics of neogentic lymphatics could be seen,such as thick wall,narrow lumen,changes of organell,etc.Conclusion: Neogentic lymphatics can be seen in transplantation tumor model of human breast infiltrating duct carcinoma in nude mice.
3.Research Advances on RGD Peptides in Diagnosis and Treatment of Neoplasms
Chinese Journal of Bases and Clinics in General Surgery 2003;0(06):-
Objective To introduce the current research status, value and development future of Arg-Gly-Asp (RGD) peptides in diagnosis and treatment of neoplasms. Methods The current literatures on advances about RGD peptides in diagnosis and treatment of neoplasms were reviewed. Results RGD peptides, specificly recognizing and combining with integrin receptors, exist in extracellular matrix (ECM) of many kinds of organisms. After combining with integrin receptors, extrinsic RGD peptides can prevent tumor cells from adhering to ECM and migrating as the competitive inhibitor of intrinsic RGD peptides, suppress agiogenesis and induce tumor cells apoptosis, showing potential value of tumor specific imaging by targetal labelling neoplasms and treating tumors combining with other methods.Conclusion RGD peptides may be a new drug for diagnosis and treatment of neoplasms.
4.Advances in Clinical Application of Fiberoptic Ductoscopy
Chinese Journal of Bases and Clinics in General Surgery 2003;0(03):-
Objective To introduce the current status of clinical application, value and perspective of fiberoptic ductoscopy.Methods The related literatures on advances in clinical application of fiberoptic ductoscopy were reviewed.Results Fiberoptic ductoscopy is now widely used in breast diseases, especially complicated with nipple discharge, and it has a higher accuracy rate than routine examinations. With ductoscopy, ductal lavage,location, biopsy and treatment can be carried out.Conclusion Fiberoptic ductoscopy has a greater value in diagnosis and treatment, we believe it will be better applied and further developed.
5.Purification and characterization of a halophilic urethanase from Klebsiella pneumoniae.
Panpan BU ; Jian CHEN ; Guocheng DU
Chinese Journal of Biotechnology 2014;30(3):404-411
Ethyl carbamate (EC) is a carcinogenic substance in many fermented foods. Enzymatic removal of ethyl carbamate from fermented foods is an important way to eliminate its potential health damage to consumers. To study the enzymatic properties of an ethyl carbamate hydrolase (urethanase) from Klebsiella pneumoniae, a strain isolated from murine somach, we purified the enzyme using ammonium sulfate precipitation, ion exchange chromatography and gel filtration chromatography. The molecular mass of this enzyme was estimated to be 55 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Its K(m) was 74 mmol/L when EC was used as the substrate. Moreover, its optimal reaction temperature was 55 degrees C, and the optimum pH was 7.0. The activity was enhanced by ethylene diamine tetraacetic acid (EDTA) and dithiothreitol (DTT), but strongly inhibited by Cu2+ and Zn2+. The enzyme was halophilic and tolerant to low concentration of ethanol. Therefore, it has the potential to remove EC from fermented foods.
Amidohydrolases
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chemistry
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isolation & purification
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Bacterial Proteins
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chemistry
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isolation & purification
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Chromatography, Gel
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Chromatography, Ion Exchange
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Electrophoresis, Polyacrylamide Gel
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Hydrogen-Ion Concentration
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Klebsiella pneumoniae
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enzymology
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Molecular Weight
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Substrate Specificity
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Temperature
6.Effects of Baobaole oral liquid on neuron excitability of feeding center in anorectic rats
Yongping DU ; Yueping ZHANG ; Guocheng ZHANG
Journal of Integrative Medicine 2007;5(5):550-4
OBJECTIVE: To investigate the effects of Baobaole oral liquid on neuronal excitability in lateral hypothalamic area (LHA) and ventromedial hypothalamic nuclear (VMN) in anorectic rats. METHODS: The anorectic rat model was established by feeding with special prepared forage for a week, and then Baobaole oral liquid, a liquid extract of a compound traditional Chinese medicine for activating spleen, was administered once a day for 3 weeks. Finally, extracellular recording from LHA and VMN neurons in rats were made in order to characterize their responses to gastric vagal nerve stimulation and intravenous injection of glucose in the normal, untreated, and Baobaole-treated groups. RESULTS: There was no statistical difference in response characteristics of LHA neurons to gastric vagal stimulation among 3 groups. The duration of VMN neuron excitation response to gastric vagal nerve stimulation in the untreated group was significantly longer than that of the normal control group (P<0.01), while the required stimulation intensity was significantly decreased (P<0.01). Moreover, among the neurons responding to the gastric vagal stimulation in the untreated group, the number of glycemia-sensitive neurons decreased in LHA and increased in VMN (P<0.01). The gastric vagal stimulation induced neuron responses in LHA and VMN of the Baobaole-treated group were not significantly changed as compared with the normal control group (P<0.01), and neither were the intravenous injection of glucose induced responses. CONCLUSION: Baobaole oral liquid can modulate the sensitivity of LHA and VMN neurons to the peripheral signal and make the coordination between LHA and VMN neurons in order to improve the appetite of anorectic rats.
7.Degradation of urea and ethyl carbamate in Chinese Rice wine by recombinant acid urease.
Jianli ZHOU ; Zhen KANG ; Qingtao LIU ; Guocheng DU ; Jian CHEN
Chinese Journal of Biotechnology 2016;32(1):74-83
Ethyl carbamate (EC) as a potential carcinogen commonly exists in traditional fermented foods. It is important eliminate urea that is the precursors of EC in many fermented foods, including Chinese Rice wine. On the basis of achieving high-level overexpression of food-grade ethanol-resistant acid urease, we studied the hydrolysis of urea and EC with the recombinant acid urease. Recombinant acid urease showed degraded urea in both the simulated system with ethanol and Chinese Rice wine (60 mg/L of urea was completely degraded within 25 h), indicating that the recombinant enzyme is suitable for the elimination of urea in Chinese Rice wine. Although recombinant acid urease also has degradation catalytic activity on EC, no obvious degradation of EC was observed. Further investigation results showed that the Km value for urea and EC of the recombinant acid urease was 0.7147 mmol/L and 41.32 mmol/L, respectively. The results provided theoretical foundation for realizing simultaneous degradation of urea and EC.
Oryza
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Recombinant Proteins
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metabolism
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Urea
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chemistry
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Urease
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metabolism
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Urethane
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chemistry
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Wine
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analysis
8.Progress in glucaric acid.
Yuying QIU ; Fang FANG ; Guocheng DU ; Jian CHEN
Chinese Journal of Biotechnology 2015;31(4):481-490
Glucaric acid (GA) is derived from glucose and commonly used in chemical industry. It is also considered as one of the "Top value-added chemicals from biomass" as carbohydrate monomers to produce various synthetic polymers and bioenergy. The demand for GA in food manufacture is increasing. GA has also attracted public attentions due to its therapeutic uses such as regulating hormones, increasing the immune function and reducing the risks of cancers. Currently GA is produced by chemical oxidation. Research on production of GA via microbial synthesis is still at preliminary stage. We reviewed the advances of glucaric acid applications, preparation and quantification methods. The prospects on production of GA by microbial fermentation were also discussed.
Biomass
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Chemical Industry
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Fermentation
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Glucaric Acid
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chemistry
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Glucose
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Polymers
9.Improving maltodextrin specificity by site-saturation engineering of subsite +1 in cyclodextrin glycosyltransferase from Paenibacillus macerans.
Qiaoyan XU ; Ruizhi HAN ; Jianghua LI ; Guocheng DU ; Long LIU ; Jian CHEN
Chinese Journal of Biotechnology 2014;30(1):98-108
By engineering the subsite +1 of cyclodextrin glycosyltransferase (CGTase) from Paenibacillus macerans, we improved its maltodextrin specificity for 2-O-D-glucopyranosyl-L-ascorbic acid (AA-2G) synthesis. Specifically, we conducted site-saturation mutagenesis on Leu194, Ala230, and His233 in subsite +1 separately and gained 3 mutants L194N (leucine --> asparagine), A230D (alanine --> aspartic acid), and H233E (histidine --> glutamic acid) produced higher AA-2G yield than the wild-type and the other mutant CGTases. Therefore, the 3 mutants L194N, A230D, and H233E were further used to construct the double and triple mutations. Among the 7 obtained combinational mutants, the triple mutant L194N/A230D/H233E produced the highest AA-2G titer of 1.95 g/L, which was increased by 62.5% compared with that produced by the wild-type CGTase. Then, we modeled the reaction kinetics of all the mutants and found a substrate inhibition by high titer of L-AA for the mutants. The optimal temperature, pH, and reaction time of all the mutants were also determined. The structure modeling indicated that the enhanced maltodextrin specificity may be related with the changes of hydrogen bonding interactions between the side chain of residue at the three positions (194, 230 and 233) and the substrate sugars.
Ascorbic Acid
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analogs & derivatives
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chemistry
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Glucosyltransferases
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genetics
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metabolism
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Hydrogen Bonding
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Kinetics
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Mutagenesis, Site-Directed
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Paenibacillus
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enzymology
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Polysaccharides
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chemistry
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Protein Engineering
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Substrate Specificity
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Temperature
10.Relations between pulse pressure and LDL-C for elderly patients with hypertension
Qingqing CHEN ; Zhiguang GAO ; Guocheng REN ; Peimin LIU ; Yuzhi DU
China Modern Doctor 2015;(12):19-21
Objective To explore the relations between pulse pressure and LDL-C for elderly patients with hyperten-sion. Methods A total of 451 elderly patients with hypertension were selected and divided into four groups. Group A was 65 to 69 years of age, group B was 70 to74 years of age, group C was 75 to 79 years of age, and group D was ≥80 years of age. They were also divided into four groups according to PP levels: PP1 group ≤40 mm Hg, PP2 group 41 to 60 mm Hg, PP3 group 61 to 80 mm Hg, and PP4 group>80 mm Hg. They were divided into LDL-C group 1 (≥2.6 mmol/L) and LDL-C group 2 (<2.6 mmol/L) according to their LDL-C levels. Distribution of different age groups in four PP groups and the effects of different levels of LDL-C on pulse pressure were analyzed. Results (1) The propor-tions of PP2 group among the four age groups were 59.41%, 48.84%, 55.45% and 51.67%. The proportions of PP4 a-mong the four age groups were 4.95%, 3.88%, 3.96% and 7.50%. (2) Compared with PP1 group, the proportion of LDL-C ≥2.6 mmol/L in PP2 group, PP3 group and PP4 group was significantly increased. Conclusion (1) PP levels in different ages groups are concentrated on 41-60 mmHg. Among elderly patients with hypertension>80 mmHg, the pro-portion of patients with advanced age (≥years of age) is relatively higher. (2) LDL-C is the risk factor of increased pulse pressure for elderly patients with hypertension.