1.Protective effect of Shouwu Yizhi decoction against vascular dementia by promoting angiogenesis.
Xiao-Ni YANG ; Chang-Sheng LI ; Chao CHEN ; Xiao-Yong TANG ; Guang-Qing CHENG ; Xia LI
Chinese Journal of Natural Medicines (English Ed.) 2017;15(10):740-750
Shouwu is a traditional Chinese medicine (TCM) with neuroprotective effect. Shouwu Yizhi decoction (SYD) was designed based on TCM theory. However, little is known about the roles of SYD in Vascular dementia (VaD). The present study aimed to evaluate the potential effects of SYD on the vascular cognitive impairment and explore the underlying mechanism by establishing focal cerebral ischemia/reperfusion (I/R) rat model to induce VaD. SYD administration (54 mg·kg) for 40 days obviously improved the vascular cognitive impairment in the middle cerebral artery occlusion (MCAO) rats as evidenced by the declined neurological deficit score and shortened escape latency via neurological deficit assessment and Morris water maze test. Moreover, SYD decreased neuron damage-induced cell death and ameliorated the ultrastructure of endothelial cells in the MCAO rats, thereby alleviating VaD. Mechanistically, SYD caused increases in the expression of vascular endothelial growth factor (VEGF), CD34 and CD31, compared with the MCAO rats in coronal hippocampus. Simultaneously, the expression level of miR-210 was elevated significantly after SYD administration, compared with the vehicle rats (P < 0.01). The expression of Notch 4 at both mRNA and protein levels was upregulated remarkably along with the notably downregulated DLL4 expression under SYD administration compared with the vehicle rats (P < 0.05). Overall, the above results indicated that SYD promoted angiogenesis by upregulating VEGF-induced miR210 expression to activate Notch pathway, and further alleviated neuron damage and ameliorated the ultrastructure of endothelial cells in the MCAO rats, ultimately enhancing the cognition and memory of MCAO rats. Therefore, our findings preliminarily identified the effect and the mechanism of action for SYD on VaD in rats. SYD could be a potential candidate in treatment of VaD.
Angiogenesis Inducing Agents
;
administration & dosage
;
Animals
;
Dementia, Vascular
;
drug therapy
;
genetics
;
metabolism
;
psychology
;
Drugs, Chinese Herbal
;
administration & dosage
;
Humans
;
Intracellular Signaling Peptides and Proteins
;
genetics
;
metabolism
;
Male
;
Membrane Proteins
;
genetics
;
metabolism
;
Memory
;
drug effects
;
Neuroprotective Agents
;
administration & dosage
;
Rats
;
Rats, Wistar
;
Receptor, Notch4
;
genetics
;
metabolism
;
Vascular Endothelial Growth Factor A
;
genetics
;
metabolism
2.Flavonoids of Echinps latifolius suppress Wnt signaling in adjuvant arthritis rats.
Cheng-Gui MIAO ; Jian XU ; Hu GAO ; Liang-Liang LIU ; Guo-Liang ZHOU ; Mei-Song QIN ; Jian-Zhong CHEN ; Cheng-Feng LI
China Journal of Chinese Materia Medica 2015;40(1):129-133
The role of flavonoids of Echinps latifolius (FELT) in Wnt signaling was investigated in adjuvant arthritis (AA) rats. The therapeutic effects of FELT on AA rats were detected by rat arthritis score and MTT. The effect of FELT gavage treatment on the Wnt signaling key gene β-catenin, C-myc and cyclin D1 in synovium from AA rats was detected by Real-time qPCR, and the effects of FELT gavage treatment on the upstream negative regulation gene SFRP 1,2,4,5 in synovium from AA rats were detected by Real-time qPCR. The results showed that FELT gavage treatment significantly inhibited arthritis score and MTT values in AA rats, significantly inhibited the expression of the Wnt signaling gene β-catenin, C-myc and cyclin D1, significantly up-regulated the expression of the up- stream negative regulation gene SFRP 1,2,4. FELT has a better therapeutic effect for AA rats.
Animals
;
Arthritis, Experimental
;
drug therapy
;
genetics
;
metabolism
;
Asteraceae
;
chemistry
;
Disease Models, Animal
;
Down-Regulation
;
drug effects
;
Drugs, Chinese Herbal
;
administration & dosage
;
Flavonoids
;
administration & dosage
;
Humans
;
Intercellular Signaling Peptides and Proteins
;
genetics
;
metabolism
;
Male
;
Membrane Proteins
;
genetics
;
metabolism
;
Rats
;
Rats, Sprague-Dawley
;
Signal Transduction
;
drug effects
;
Synovial Membrane
;
drug effects
;
metabolism
;
Wnt Signaling Pathway
;
drug effects
;
beta Catenin
;
metabolism
3.Effects of Topical Intranasal Doxycycline Treatment in the Rat Allergic Rhinitis Model.
Mehmet Ozgur AVINCSAL ; Seda OZBAL ; Ahmet Omer IKIZ ; Cetin PEKCETIN ; Enis Alpin GUNERI
Clinical and Experimental Otorhinolaryngology 2014;7(2):106-111
OBJECTIVES: Allergic rhinitis (AR) is a chronic upper respiratory tract disease that inflames the mucous membranes of the nose and occurs when circulating inflammatory cells including eosinophils and basophils migrate to and accumulate in the inflammation area by passing through the interstitium and capillary walls. To pass through these barriers, the inflammatory cells degrade extracellular matrix proteins. Matrix metalloproteinases (MMPs) released by inflammatory cells mediate the degradation of these proteins. MMPs have synthetic inhibitors and doxycycline, a tetracycline antibiotic, inhibits MMPs. This study investigated the efficiency of intranasal doxycycline in decreasing the symptoms and inflammatory cell infiltration in an animal model of AR. METHODS: AR was created in female Wistar rats by repeated intranasal challenge with ovalbumin by intraperitoneal injection. For 15 days, topical intranasal doxycycline was administered one hour before ovalbumin administration. Following intranasal administration, nasal symptoms were scored and the nasal mucosae of all rats were evaluated histopathologically. To investigate tissue changes, hematoxyline-eosin and Alcian blue/periodic acid Schiff stains were used. As well, cilia loss, goblet cell changes, vascular congestion, vascular proliferation, inflammatory cell infiltration, eosinophil infiltration and the degree of hypertrophy in chondrocytes were evaluated with light microscopy. RESULTS: Typical symptoms of AR were decreased by intranasal doxycycline administration. These effects were stable after repeated intranasal ovalbumin administration. Histological evaluation of doxycycline treated rats did not reveal typical inflammatory changes associated with AR. CONCLUSION: MMPs may have crucial functions in AR and topical intranasal doxycycline, which decreases inflammatory cell infiltration, may offer an alternative therapy for AR.
Administration, Intranasal
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Animals
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Basophils
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Capillaries
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Chondrocytes
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Cilia
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Coloring Agents
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Doxycycline*
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Eosinophils
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Estrogens, Conjugated (USP)
;
Extracellular Matrix Proteins
;
Female
;
Goblet Cells
;
Humans
;
Hypertrophy
;
Inflammation
;
Injections, Intraperitoneal
;
Matrix Metalloproteinase Inhibitors
;
Matrix Metalloproteinases
;
Microscopy
;
Models, Animal
;
Mucous Membrane
;
Nasal Mucosa
;
Nose
;
Ovalbumin
;
Rats*
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Rats, Wistar
;
Respiratory Tract Diseases
;
Rhinitis*
;
Tetracycline
4.Effects of suppressed autophagy on mitochondrial dynamics and cell cycle of N2a cells.
Meng-cui GUI ; Bo CHEN ; Shan-shan YU ; Bi-tao BU
Journal of Huazhong University of Science and Technology (Medical Sciences) 2014;34(2):157-160
Autophagy dysregulation, mitochondrial dynamic abnormality and cell cycle re-entry are implicated in the vulnerable neurons of patients with Alzheimer's disease. This study was designed to testify the association among autophagy, mitochondrial dynamics and cell cycle in dividing neuroblastoma (N2a) cells. The N2a cells were cultured in vitro and treated with different concentrations of 3-methyladenine (3-MA). The cell viability was detected by methyl thiazolyl tetrazolium (MTT) assay. They were randomly divided into control group (cells cultured in normal culture medium) and 3-MA group (cells treated with 10 mmol/L 3-MA). The cell cycle was analyzed in the two groups 3, 6, 12, and 24 h after treatment by flow cytometry. Western blotting was used to evaluate the expression levels of mitofission 1 (Fis1), mitofusin 2 (Mfn2), microtubule-associated protein 1 light chain 3 (LC3), cell cycle-dependent kinase 4 (CDK4) and cdc2. The flow cytometry revealed that the proportion of cells in G(2)/M was significantly increased, and that in G0/G1 was significantly reduced in the 3-MA group as compared with the control group. Western blotting showed that the expression levels of Fis1, LC3, and CDK4 were significantly up-regulated in the 3-MA group at the four indicated time points as compared with the control group. Mfn2 was initially decreased in the 3-MA group, and then significantly increased at 6 h or 12 h. Cdc2 was significantly increased in the 3-MA group at 3 h and 6 h, and then dropped significantly at 12 h and 24 h. Our data indicated that 3-MA-induced suppressed autophagy may interfere with the cell cycle progression and mitochondrial dynamics, and cause cell death. There are interactions among cell cycle, mitochondrial dynamics and autophagy in neurons.
Adenine
;
administration & dosage
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analogs & derivatives
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Apoptosis
;
drug effects
;
Autophagy
;
drug effects
;
genetics
;
CDC2 Protein Kinase
;
Cell Cycle
;
drug effects
;
genetics
;
Cell Division
;
drug effects
;
Cell Line, Tumor
;
Cell Proliferation
;
drug effects
;
Cell Survival
;
drug effects
;
Cyclin B
;
biosynthesis
;
Cyclin-Dependent Kinases
;
Gene Expression Regulation
;
drug effects
;
Humans
;
Membrane Proteins
;
biosynthesis
;
Microtubule-Associated Proteins
;
biosynthesis
;
Mitochondrial Dynamics
;
drug effects
;
genetics
;
Mitochondrial Proteins
;
biosynthesis
;
Neuroblastoma
;
Signal Transduction
;
drug effects
5.Protect effects and the underlying mechanisms of myricitrin against vascular endothelial cells apoptosis induced by oxidative stress.
Gui-Bo SUN ; Meng QIN ; Yun LUO ; Rui-Le PAN ; Xiang-Bao MENG ; Min WANG ; Yan-Hui ZOU ; Xiao-Bo SUN
Acta Pharmaceutica Sinica 2013;48(4):615-620
This study is to report the study of protective effects of myricitrin against oxidative stress-induced apoptosis of vascular endothelial cells and the investigation of the possible mechanisms of action of myricitrin. The model of H2O2-induced apoptosis of vascular endothelial cells was used to determine the protective effects of myricitrin. The levels of LDH, MDA and the activities of SOD, NO were measured using the respective kits. The H2O2-induced apoptosis of vascular endothelial cells was detected using MTT reduction, TUNEL assay, JC-1 and ROS staining. The activation of Caspase-3 was also measured by fluorometry. The expression of apoptosis-related proteins was determined with Western blotting assay. Myricitrin had significant protective effects against H2O2-induced apoptosis of vascular endothelial cells in a time- and dose-dependent manner. The results show that myricitrin could attenuate H2O2-induced decrease in the activities of SOD (P < 0.01). Myricitrin could decrease the levels of LDH, MDA and increase cell viability and the mitochondrial membrane potential (P < 0.01). Myricitrin had protective effects in a dose-dependent manner between 32 micromol x L(-1) to 64 micromol x L(-1). Myricitrin pretreatment could attenuate H2O2-induced increase of p-ERK. Moreover, myricitrin pretreatment could up-regulate the expression of the anti-apoptotic protein Bcl-2, down-regulate the expression of the pro-apoptotic protein Bax, and decrease the expression of Caspase-3, 9. In conclusion, myricitrin had significant protective effects against H2O2-induced apoptosis of vascular endothelial cells. Myricitrin can enhance the activities of anti-oxidative enzymes and decrease the production of free radicals. The possible mechanisms of action of myricitrin are due to myricitrin-mediated inhibition of phosphorylation of the apoptosis signaling pathways-related kinase ERK, up-regulation of the expression of the anti-apoptotic protein, and down-regulation of the expression of the pro-apoptotic protein.
Apoptosis
;
drug effects
;
Caspase 3
;
metabolism
;
Caspase 9
;
metabolism
;
Cell Survival
;
drug effects
;
Cells, Cultured
;
Dose-Response Relationship, Drug
;
Endothelial Cells
;
cytology
;
Flavonoids
;
administration & dosage
;
pharmacology
;
Humans
;
Hydrogen Peroxide
;
toxicity
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L-Lactate Dehydrogenase
;
metabolism
;
Malondialdehyde
;
metabolism
;
Membrane Potential, Mitochondrial
;
drug effects
;
Nitric Oxide
;
metabolism
;
Oxidative Stress
;
drug effects
;
Protective Agents
;
administration & dosage
;
pharmacology
;
Proto-Oncogene Proteins c-bcl-2
;
metabolism
;
Reactive Oxygen Species
;
metabolism
;
Superoxide Dismutase
;
metabolism
;
bcl-2-Associated X Protein
;
metabolism
6.Effects of jin chai antiviral capsule on IFITM3 expression in mice.
Ju-Ying ZHONG ; Xiao-Lan CUI ; Yu-Jing SHI ; Shan-Shan GUO ; Ying LIU ; Fang-Zhou LIU ; Ying-Jie GAO ; Ya-Hong JIN ; Hong-Xin CAO
Acta Pharmaceutica Sinica 2012;47(7):904-908
This study is to investigate the treatment of Jin Chai antiviral capsule for influenza virus FM1/47 (H1N1) infection. The model of pneumonia was established by dropping influenza virus into the nose of normal mice, real-time PCR and Western blot technique were used to detect the virus load and the interferoninducible transmembrane protein3 (IFITM3) in lung of mice at the 1st day, 3rd day, 5th day and 7th day after affected. The results showed that Jin Chai antiviral capsule in large, middle, small dose groups can decrease virus load significantly at each time point, after being affected (P<0.05, P<0.01), Jin Chai antiviral capsule can increase the interferoninducible transmembrane protein3 in lung of mice, large dose groups are significantly higher in expression of IFITM3 compared with model group at each time point (P<0.05, P<0.01). Middle dose groups are significantly higher in expression of IFITM3 compared with model group at the 3th day and the 5th day (P<0.05), small dose groups are significantly higher in expression of IFITM3 compared with model group at the 3th day (P<0.05). It can be concluded that Jin Chai antiviral capsule exerts antiviral effects against influenzavirus by raised expression of IFITM3.
Animals
;
Antiviral Agents
;
administration & dosage
;
pharmacology
;
Capsules
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Dose-Response Relationship, Drug
;
Drug Combinations
;
Drugs, Chinese Herbal
;
administration & dosage
;
pharmacology
;
Female
;
Influenza A Virus, H1N1 Subtype
;
drug effects
;
Lung
;
metabolism
;
Male
;
Membrane Proteins
;
metabolism
;
Mice
;
Mice, Inbred ICR
;
Orthomyxoviridae Infections
;
metabolism
;
virology
;
Plants, Medicinal
;
chemistry
;
Pneumonia
;
metabolism
;
virology
;
Viral Load
;
drug effects
7.The reno-protective effect of a phosphoinositide 3-kinase inhibitor wortmannin on streptozotocin-induced proteinuric renal disease rats.
Sang Hoon KIM ; Young Woo JANG ; Patrick HWANG ; Hyun Jung KIM ; Gi Yeon HAN ; Chan Wha KIM
Experimental & Molecular Medicine 2012;44(1):45-51
Diabetic nephropathy (DN) is a progressive kidney disease that is caused by injury to kidney glomeruli. Podocytes are glomerular epithelial cells and play critical roles in the glomerular filtration barrier. Recent studies have shown the importance of regulating the podocyte actin cytoskeleton in early DN. The phosphoinositide 3-kinase (PI3K) inhibitor, wortmannin, simultaneously regulates Rac1 and Cdc42, which destabilize the podocyte actin cytoskeleton during early DN. In this study, in order to evaluate the reno-protective effects of wortmannin in early DN by regulating Rac1 and Cdc42, streptozotocin (STZ)-induced proteinuric renal disease (SPRD) rats were treated with wortmannin. The albuminuria value of the SPRD group was 3.55 +/- 0.56 mg/day, whereas wortmannin group was 1.77 +/- 0.48 mg/day. Also, the albumin to creatinine ratio (ACR) value of the SPRD group was 53.08 +/- 10.82 mg/g, whereas wortmannin group was 20.27 +/- 6.41 mg/g. Changes in the expression level of nephrin, podocin and Rac1/Cdc42, which is related to actin cytoskeleton in podocytes, by wortmannin administration were confirmed by Western blotting. The expression levels of nephrin (79.66 +/- 0.02), podocin (87.81 +/- 0.03) and Rac1/Cdc42 (86.12 +/- 0.02) in the wortmannin group were higher than the expression levels of nephrin (55.32 +/- 0.03), podocin (53.40 +/- 0.06) and Rac1/Cdc42 (54.05 +/- 0.04) in the SPRD group. In addition, expression and localization of nephrin, podocin and desmin were confirmed by immunofluorescence. In summary, we found for the first time that wortmannin has a reno-protective effect on SPRD rats during the early DN. The beneficial effects of wortmannin in SPRD rats indicate that this compound could be used to delay the progression of the disease during the early DN stage.
Albumins/metabolism
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Androstadienes/*administration & dosage/pharmacology
;
Animals
;
Creatinine/blood
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Desmin/genetics/metabolism
;
Diabetes Mellitus, Experimental/*drug therapy/metabolism/pathology
;
Diabetic Nephropathies/*drug therapy/metabolism/pathology
;
Disease Models, Animal
;
Humans
;
Intracellular Signaling Peptides and Proteins/genetics/metabolism
;
Kidney/*pathology
;
Membrane Proteins/genetics/metabolism
;
Phosphatidylinositol 3-Kinases/*antagonists & inhibitors
;
Podocytes/*drug effects/metabolism/pathology
;
Rats
;
Rats, Inbred Strains
;
cdc42 GTP-Binding Protein/genetics/metabolism
;
rac1 GTP-Binding Protein/genetics/metabolism
8.Effects of arsenic trioxide combined with bortezomib on apoptosis of multiple myeloma cell line KM3 and its mechanisms.
Qun-Fang GE ; Gui-Fang OUYANG ; Ying CHEN ; Yi ZHANG ; Qi-Tian MU ; Ying LU
Journal of Experimental Hematology 2012;20(1):112-115
This study was purposed to investigate the effect of bortezomib (Bor) and arsenic trioxide (As(2)O(3)) combination on multiple myeloma cell line KM3 and its mechanisms. KM3 cells were cultured with different concentration of Bor or As(2)O(3) as well as both for a certain time. The cell proliferation was analysed by MTT assay and the concentration of 50% proliferation inhibition (IC(50)) was calculated. Early apoptosis and late apoptosis of KM3 cells were detected by Annexin-V-FITC Kit, and the change of transmembrane potential was measured by flow cytometry. mRNA of Caspase-3, Bim and Bcl-xL were detected by RT-PCR. The results showed that the proliferation inhibitory rate of KM3 cells treated by Bor plus As(2)O(3) was much higher than that of KM3 cells treated by Bor only for 72 h [ (27.64 ± 0.81)% vs (21.67 ± 2.20)%, P < 0.05]. There were more KM3 cells treated by Bor plus As(2)O(3) in early apoptosis at 48 h and late apoptosis at 72 h than that of KM3 cells treated only by Bor [ (53.20 ± 3.70)% vs (35.40 ± 2.58)%, P < 0.01; (63.96 ± 2.97)% vs (54.08 ± 3.76)%, P < 0.01]. Transmembrane potential (Δψm) of KM3 cells treated by Bor plus As(2)O(3) decreased more at 48 h, as compared with Bor alone. The expression levels of caspase-3 mRNA and Bim mRNA in KM3 cells treated with Bor plus As(2)O(3) were higher than that in KM3 cells treated with Bor alone. But the expression level of Bcl-xL mRNA was lower than that in KM3 cells treated with Bor alone. It is concluded that As(2)O(3) can enhance the apoptosis-inducing effect of Bor on multiple myeloma cell line KM3, which is associated with decreasing the expression of Bcl-xl mRNA and increasing the expression of Caspase-3 and Bim mRNA.
Apoptosis
;
drug effects
;
Apoptosis Regulatory Proteins
;
metabolism
;
Arsenicals
;
administration & dosage
;
pharmacology
;
Bcl-2-Like Protein 11
;
Boronic Acids
;
administration & dosage
;
pharmacology
;
Bortezomib
;
Caspase 3
;
metabolism
;
Cell Line, Tumor
;
Humans
;
Membrane Proteins
;
metabolism
;
Multiple Myeloma
;
metabolism
;
pathology
;
Oxides
;
administration & dosage
;
pharmacology
;
Proto-Oncogene Proteins
;
metabolism
;
Pyrazines
;
administration & dosage
;
pharmacology
;
bcl-X Protein
;
metabolism
9.Clinical characteristics and effect of secondary individualized therapy in chronic hepatitis B patients infected with the rtA181 mutation hepatitis B virus.
Fen-zhi JI ; Lei WANG ; Bao-hua YANG ; Jing-jie ZHAO ; Feng LIU ; Yan XUE ; Tao LI
Chinese Journal of Hepatology 2012;20(4):280-284
OBJECTIVETo investigate chronic hepatitis B (CHB) patients infected with the antiviral-resistant rtA181 mutation hepatitis B virus (HBV) who have been unresponsive to general therapy to determine the effects of individualized therapy.
METHODSFifty-four patients with confirmed rtA181 mutation and who experienced virological breakthrough during nucleus(t)ide analogue (NUC) treatment were enrolled in this prospective cohort study. Their serum levels of HBV DNA, hepatitis B surface antigen (HBsAg), and alanine transaminase (ALT) were tested. Each patient was genotyped by pyrosequencing for 10 mutation sites in the HBV P gene that have been previously correlated to NUC efficacy. Each patient's antiviral therapy and response history was analyzed in regard to their particular mutation pattern. The serological index was determined for carriers of the rtA181T/V mutation. The secondary individualized treatment included adding/switching to entecavir (ETV; group A) or adding telbivudine (LdT; group B) upon confirmation of drug resistance. Effect of individualized treatment was analyzed by T test and Mann-Whitney U test for continuous variables with normal or skewed distributions, respectively. Categorical variables were analyzed by the Chi-squared ( x² ) or Fisher's exact tests.
RESULTSThe rtA181T mutation was found in 64.8% (35/54) of patients with rtA181 mutation HBV. The most frequent previously administered medications were adefovir dipivoxil (ADV) and lamivudine (LAM). Multi-site rtA181 mutations occurred more frequently in the patients with multi-NUCs history (57.6%) than in those with single NUCs history (28.6%) (x²=4.342, P less than 0.05). Serum HBV DNA level at virological breakthrough was lower than that at baseline of the first antiviral treatment (5.66+/-1.01 vs. 6.75+/-0.81 log10 copies/ml; t=-4.210, P less than 0.01). The serum HBsAg level was higher in carriers of the rtA181T mutation than in carriers of the rtA181V mutation (3.80+/-0.45 vs. 3.46+/-0.60 log10 IU/ml; t=2.109, P less than 0.05). In patients with serum HBV DNA more than or equal to 6 log10 copies/ml at viral breakthrough, 100% (8/8) of patients in the secondary treatment group A and 75% (3/4) patients in the secondary treatment group B exhibited virological response at week 24 after intervention. Undetectable HBV DNA was achieved in three patients of group A and one patient of group B. In patients with serum HBV DNA less than 6 log10 copies/ml at viral breakthrough, 100% (14/14) of patients in group A and 71.4% (5/7) of patients in group B exhibited biological response at week 24 after intervention. The serum HBV DNA level decreased to undetectable levels in 12 patients of group A and four patients of group B.
CONCLUSIONThe rtA181 mutation pattern correlates with previous antiviral therapy response. In addition, multi-site rtA181 mutations occur more frequently in patients with a history of multi-NUCs therapy. Adding or switching rtA181 carriers to ETV produces a more robust virological suppression than adding LdT.
Adult ; Aged ; Antiviral Agents ; administration & dosage ; therapeutic use ; Drug Resistance, Viral ; genetics ; Female ; Hepatitis B virus ; drug effects ; genetics ; Hepatitis B, Chronic ; drug therapy ; virology ; Humans ; Male ; Membrane Proteins ; genetics ; Middle Aged ; Point Mutation ; Prospective Studies ; Retrospective Studies ; Young Adult
10.Repeated morphine pretreatment reduces glutamatergic synaptic potentiation in the nucleus accumbens induced by acute morphine exposure.
Xiao-Jie WU ; Jing ZHANG ; Chun-Ling WEI ; Zhi-Qiang LIU ; Wei REN
Acta Physiologica Sinica 2012;64(2):170-176
Repeated exposure to morphine leads to the addiction, which influences its clinical application seriously. The glutamatergic projection from prefrontal cortex (PFC) to the nucleus accumbens (NAc) plays an important role in rewarding effects. It is still unknown whether morphine exposure changes PFC-NAc synaptic transmission. To address this question, in vivo field excitatory postsynaptic potentials (fEPSPs) induced by electric stimulating PFC-NAc projection fibers were recorded to evaluate the effect of acute morphine exposure (10 mg/kg, s.c.) on glutamatergic synaptic transmission in NAc shell of repeated saline/morphine pretreated rats. It was showed that acute morphine exposure enhanced fEPSP amplitude and reduced paired-pulse ratio (PPR) in saline pretreated rats, which could be reversed by following naloxone injection (1 mg/kg, i.p.), an opiate receptor antagonist. However, repeated morphine pretreatment significantly inhibited both the enhancement of fEPSP amplitude and reduction of PPR induced by acute morphine exposure. Those results indicate that the initial morphine exposure enhances PFC-NAc synaptic transmission by pre-synaptic mechanisms, whereas morphine pretreatment occludes this effect.
Animals
;
Excitatory Postsynaptic Potentials
;
drug effects
;
physiology
;
Female
;
Glutamate Plasma Membrane Transport Proteins
;
metabolism
;
Glutamates
;
metabolism
;
Morphine
;
administration & dosage
;
Morphine Dependence
;
physiopathology
;
Nucleus Accumbens
;
physiopathology
;
Prefrontal Cortex
;
physiopathology
;
Rats
;
Rats, Sprague-Dawley

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