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OBJECTIVES@#This study aimed to evaluate the color stability of tetracycline teeth restored with ceramic veneers of different thicknesses combined with different resin cement systems after aging.@*METHODS@#Twenty patients with tetracycline teeth, including two maxillary central incisors, were selected clinically. The patients were randomly divided into four groups and restored with 0.5 and 0.75 mm ceramic veneers by using a veneer adhesive system, either with light-cured or dual-cured reaction. The color difference (ΔE) values after cementation and 1, 6, 12, and 24 months of use were obtained by quantification of L*, a*, and b* values with a colorimeter. The results were analyzed statistically with two-way ANOVA and Student's @*RESULTS@#The ΔE values of ceramic veneers detected after aging were less than 2.25. The 0.5 mm groups exhibited greater color change than the 0.75 mm-thick veneers (@*CONCLUSIONS@#Resin cements and veneer thickness influence the color of ceramic veneers after aging. Cementation of veneers with either dual- or light-cured resin cements does not affect the long-term color stability of tetracycline teeth differently.
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Humans , Ceramics , Color , Dental Porcelain , Dental Veneers , Materials Testing , Resin Cements , TetracyclinesABSTRACT
OBJECTIVE@#To investigate the effects of autophagy inhibitor ROC-325 and its combination with bortezomib on the proliferation, apoptosis and autophagy of multiple myeloma cell lines.@*METHODS@#Multiple myeloma cells were treated with ROC-325 at different concentration. The cell proliferation was detected by CCK-8. Apoptosis was determined by Caspase-3/7 and Caspase-9 activity assays. Autophagy was detected by monodansylcadaverine staining. The apoptosis-related proteins (PARP and Caspase-3) and autophagy-related proteins (P62, Beclin-1, and LC3A/B) were analyzed by Western blot. The combined effect with bortezomib on bortezomib-resistant cell line was detected by CCK-8.@*RESULTS@#ROC-325 inhibited the proliferation of RPMI 8226, RPMI 8226-BTZ100, U266 and IM9 cells in a dose-dependent manner (r=-0.8275, r=-0.9079, r=-0.9422, r=-0.9305), the 72 h IC@*CONCLUSION@#ROC-325 can inhibit the proliferation, induce the apoptosis of myeloma cells through the mitochondrial pathway, inhibit the autophagy of myeloma cells by affecting the fusion of autophagosomes and lysosomes, and overcome bortezomib resistance by the combination of ROC-325 with bortezomib.
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Humans , Apoptosis , Autophagy , Bortezomib/pharmacology , Cell Line, Tumor , Cell Proliferation , Hydroxychloroquine/analogs & derivatives , Multiple MyelomaABSTRACT
Eight polyacetylenes were isolated from the extract of the stems and leaves of Chrysanthemum morifolium by various chromatographic methods. Their structures were determined as 2E,4E,12Z-tetradecatriene-1-pyrrolidine-1-oxo-8,10-diynoic (1), tetradeca-2E,4E,12E-trien-8,10-diynoic acid pyrrolidide (2), tetradeca-2E,4E-dien-8,10-diynoic acid pyrrolidide (3), tetradeca-2E,4E,10Z-trien-8-ynoic acid pyrrolidide (4), 2E,4E,12E-tetradecatriene-8,10-diynoic acid isobutylamide (5), 2E,4E-undecyldiene-8,10-diynoic acid isobutylamide (6), 2E,4E,10E-N-isobutyl-2,4,10-tetradecatrien-8-ynoic acid amide (7), and undeca-2E,4E-diene-8,10-diynoic acid phenylethylamide (8) by spectroscopic methods, including UV, IR, ESI-MS, HR-ESI-MS, 1D and 2D NMR spectra. Among them, compound 1 is a new polyacetylene, and compounds 2-8 were isolated from this plant for the first time. Compounds 5-8 inhibited the proliferation of A549 cell significantly at certain concentration, showing potent antitumor activity.
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Dendrobium officinale Kimura et Migo (D. officinale) is a famous traditional Chinese medicine (TCM). A mixture of D. officinale and American ginseng has been shown to enhance cell-mediated immunity, humoral immunity, and monocyte/macrophage functions in mice. Here, the effects of a D. officinale and American ginseng mixture on the structure of gut microbial community in dogs were examined using high-throughput 16S rRNA gene amplicon sequencing. The data revealed that while the mixture did not change the diversity of gut microbial community significantly, differences among individuals were significantly reduced. Furthermore, the mixture-responsive operational taxonomic units (OTUs) exhibited a phase-dependent expression pattern. Fifty-five OTUs were found to exhibit a mixture-induced expression pattern, among which one third were short-chain fatty acid (SCFA)-producing genera and the others were probiotic genera included Lactobacillus spp., Sutterella, Alistipes, Anaerovorax, Bilophila, Coprococcus, Gordonibacter, Oscillibacter, among others. By contrast, 36% of the OTUs exhibiting a mixture-repressed expression pattern were disease-associated microorganisms, and six genera, namely Actinomyces, Escherichia/Shigella, Fusobacterium, Slackia, Streptococcus and Solobacterium, were associated with cancer. In addition, five genera were closely associated with diabetes, namely Collinsella, Rothia, Howardella, Slackia and Intestinibacter. Our results indicate that this D. officinale and American ginseng mixture may be used as a prebiotic agent to enhance SCFA-producing genera and prevent gut dysbiosis.
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The chemical constituents of Rehmanniae Radix Preparatawere prepared according to the traditional method of "jiu zheng jiu shai" and investigated using multiple chromatographic methods. Six alkaloids were isolated and their structures were elucidated from spectral data and physicochemical properties, as follows: rehmanniae alkaloid A (4-{[(5-O-á-D-galactopyranosyloxy)methyl]-1H-pyrrole-2-carbaldehyde-1-yl}butyric acidmethyl ester) (1), baimantuoluoamide B (2), capparisine C (3), harman-3-carboxylic acid (4), (2S)-1-[2-(furan-2-yl)-2-oxoethyl]-5-oxopyrrolidine-2-carboxylate (5), and 1-[2-(furan-2-yl)-2-oxoethyl]pyrrolidin-2-one (6). Among them, compound 1 is a new alkaloid. Compounds 2-6 were newly isolated from Rehmannia glutinosa Libosch.The effect of compounds 1-6 on NRK-52e cell injury induced by LPS was investigated. The results show that compounds 1-3 exhibit protective effects against LPS-induced damage to NRK-52e cells.
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Objective To study the chemical constituents from Calystegia sepium. Methods The compounds were isolated and purified by silica gel column chromatography, Sephadex LH-20, ODS column chromatography, preparative HPLC and so on. Their structures were determined on the basis of physicochemical properties and their spectroscopic data, as well as literatures. Results A total of 20 compounds were separated and identified as tyrosol (1), quercetin-3-O-β-D-glucopyranoside (2), scutellarein-7-O-β- glucopyranoside (3), kaempferol-3-O-β-D-glucopyranoside (4), kaempferol-3-O-galactoside (5), kaempferol-3-O-β-robinobioside (6), nicotiflorin (7), rutin (8), uridine (9), tachioside (10), 2-methoxy-4-(2’-hydroxyethyl)-phenyl-1-O-β-D-glucopyranoside (11), 4-hydroxyphenethylol-4-O-β-D-glucopyranoside (12), polybotrin (13), pyridine-3,5-dicarboamide (14), skimmin (15), benzylalcohol-β-D-glucopyranoside (16), 5-hydroxyl-2-hydroxymethylpyridine (17), picein (18), 5-hydroxymethyl-furaldehyde (19), and sessiline (20). Conclusion Compounds 1-20 are isolated from Calystegia sepium for the first time.
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Objective To construct a comprehensive evaluation model of long-term care for the elderly based on the situation of our country,which is suitable for the family,community and the pension service organization. Methods The model index item pool (7 one class indexes and 133 two class indexes) formed by literature research, theoretical extraction and qualitative interview were taken as the research object.To screen the model parameters by using the Delphi method,then formed a index system of hierarchical comprehensive evaluation model of long term care for the elderly. Results 25 experts were from 10 provinces of a total of 23 Medical Colleges and affiliated hospital,positive coefficients for the first round of 83.33% and the second round of 100.00%,the average value of the two authority coefficients were both >0.90, the coordination coefficient of the evaluation index for the first round of 0.221 and the second round of 0.266(both P<0.05).The primary model index system consists of 7 first level indicators,a total of 13 secondary indicators.Among them,the"daily life ability","cognitive ability","falling risk"and"pressure sore risk" evaluation were using very mature scales, the "medical care project", "abnormal performance/symptom" and "self care knowledge needs" evaluation were independently established in this study. Conclusions Preliminary construction process of the index system for the comprehensive evaluation model of long term care for the elderly was rigorous and had better theoretical support,and the Delphi method experts had higher degree of attention and participate in the research content, experts had good representativeness,can effectively guarantee the reliability of the selected items.
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Objective To investigate the cell morphology and expression of 5-hydroxytryptamine transporter(5-HTT) in hippocampal CA1 region of depression rats induced by adolescent and post-adult stress,and to observe the inter-vention effect of modified Sini San (MSS). Methods One hundred and thirty-two Wistar rats were randomly divided into blank group,model group,JSS group,and fluoxetine group,33 rats in each group. And then the rats in each group were randomly subdivided into adolescent group, adult group, post-adult group acaccording to the age day, 11 rats in each subgroup. Age day 44,56 and 78 were used as the sampling time points for adolescent group,adult group,post-adult group respectively. Chronic unpredictable mild stress(CUMS)rat model was used. From day 21 to 44 and from day 57 to 78, the rats were modeled and given medication, but from day 44 to 55, the rats were fed normally. The rat general condition and body mass of various groups were observed,the cell morphology of hippocampal CA1 region was observed by hematoxylin-eosin (HE) staining , and the distribution of 5-hydroxytryptamine transporter (5-HTT)positive cells in CA1 region of hippocampus was observed by immunohistochemical staining. Results The general condition of the rats at different age stages in the model group was poor,while that in MSS group and fluoxetine group was improved obviously. The body mass of rats at different age stages in the model group was obviously decreased (P<0.01 compared with the blank group). After adulthood stage,the body mass of rats in model group, MSS group, and fluoxetine group was lower than that of the blank group(P < 0.01), but there was no difference between the 3 groups (P > 0.05). In aspect of cell morphological manifestation in hippocampal CA1 region, rats in the adolescent model group had more deeply-staining atrophy neurons, with unclear hyperchromatic nucleus and cytoplasm. The morphological manifestations in modeled rats at adult stage and post-adulthood stage showed progressive aggravation,manifested as a large amount of neurons stained deeply with unclear nucleus and cytoplasm, and a small amount of glial cells proliferated. Compared with the model group at the same stage,the neuronal atrophy and deeply staining decreased in fluoxetine group and MSS group. The average optical density value of 5-HTT expression in the model group was decreased significantly at the adult stage and after adulthood stage(P<0.05 or P<0.01 compared with the blank group). Compared with the model group, the average optical density value of 5-HTT expression in MSS group after adulthood stage, and in the fluoxetine group at the adult stage and after adulthood stage were increased (P<0.05 or P<0.01). Conclusion Rats suffering CUMS in adolescence presents depressive behavior, and post-adult stimulation can aggravates depression. 5-HTT expression in hippocampus may be an important pathway for MSS to achieve the therapeutic efficacy.
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Objective To investigate the efficacy and safety of paroxetine in the treatment of post-stroke depression and anxiety.Methods Patients with post-stroke depression and anxiety (312 cases) were randomly divided into observation and control groups.All patients were given routine,symptomatic,supportive treatment and rehabilitation training,psychological intervention,in addition,the observation group was treated with paroxetine hydrochloride.The Hamilton Depression Scale (HAMD) score,anxiety scale (HAMA) score,plasma substance P (SP),neuropeptide Y (NPY),cortisol (Cor) content and side effects scale (TESS) score of both groups before and after treatment were analyzed and compared.Results After treatment,the HAMD and HAMA scores of two groups were significantly decreased,and those of the observation group was significantly lower than the control group (P ＜ 0.05).The clinical curative effect of the observation group was better than that of the control group (P ＜ 0.05).In both groups,the levels of SP and Cor were significantly decreased,NPY was significantly increased,and the improvement of the observation group was higher than that of the control group (P ＜ 0.05).In the observation group,some patients had anorexia,nausea,dizziness,insomnia and other reactions,but they were tolerant,and there was no significant difference in the TESS score between the observation group and control group.Conclusion Paroxetine treatment of post-stroke depression/anxiety can reduce depression and anxiety symptoms,improve neuropeptide and cortisol levels,and have good curative effect and good safety.It is worthy of clinical application and further study.
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Objective To study the differences in 24 h ambulatory blood pressure of healthy young men between the plateau and the plains.Methods A total of 100 young men were enrolled in this study.They underwent 24 h ambulatory blood pressure monitoring on the plateau and on the plains respectively.The data was analyzed by SPSS.17.Results The 24 h mean systolic blood pressure (24HMSBP) and diastolic blood pressure (24HMDBP),day (6:00-22:00) mean systolic blood pressure (DMSBP) and diastolic blood pressure (DMDBP),night (22:00-6:00) mean systolic blood pressure (NMSBP) and diastolic blood pressure (NMDBP),24 h mean heart rate (24MHR),HRmax,HRmin,24 h systolic blood pressure load (24HSBPL) and diastolic blood pressure load (24HDBPL),day (6:00-22:00) systolic blood pressure load (DSBPL) and diastolic blood pressure load (DDBPL),night (22:00-6:00) systolic blood pressure load (NSBPL) and diastolic blood pressure load (NDBPL) were significantly different between the plateau and plains (all P ＜ 0.05).However,the systolic blood pressure decrease rate (SBPDR) and the diastolic blood pressure decrease rate (DBPDR),day systolic blood pressure coefficient of variation (DSBPCV) and diastolic blood pressure coefficient of variation (DBPCV),night systolic blood pressure coefficient of variation (NSBPCV) and diastolic blood pressure coefficient of variation (NBPCV) were not significantly different (P ＞ 0.05).Conclusion The systolic blood pressure (SBP)and diastolic blood pressure (DBP) on the plateau are significantly higher than those on the plains.24HMDBP and DMDBP increase more significantly on the plateau than those of SBP.The blood pressure load (BPL) on the plateau is higher than that on the plains,with a higher degree of dispersion,so are the 24 h mean heart rate (24MHR),HRmax,and HRmin.
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Polypeptides play a vital role in physiological processes of life. The pharmacological and medical value of polypeptides has attracted the attention of researchers in recent years. Aptamers are short, single stranded DNA or RNA which developed by an in vitro process called systematic evolution of ligands by exponential enrichment ( SELEX ) . Aptamers can bind targets with high affinity and specificity. Hence, aptamer is also called "chemical antibody" or "chemist's antibody". To date, there are two main application aspects for polypeptides-targeted aptamers. First, aptamer can be used as specific affinitive elements based on their ability of recognition, which would be applied to polypeptides detection or imaging. The other one is that aptamer can also be used as antagonists based on their ability of inhibiting, which can restrict the activity of polypeptides and block the downstream signaling pathways in vivo, thus can be used to treat the disease associated with polypeptides. In this review, we summarize the numbers of polypeptides-targeted aptamers and the related applications in vitro and in vivo. Current issues and development trends throughout the screening, characterizing and applying of polypeptides-targeted aptamers are also discussed.
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AIM:To evaluate the effects of atorvastatin (ATO) on atrial electrical remodeling in a rabbit mo-del of chronic atrial fibrillation (AF) produced by 3 weeks of rapid atrial pacing (RAP). METHODS:The sternotomy was performed and the pacing and testing electrodes were fixed to the left atria of 24 New Zealand white rabbits. The ani-mals were randomly divided into 3 groups. The rabbits in model group and ATO group were subjected to RAP for 3 weeks, and then were treated with placebo and ATO(2.5 mg·kg-1·d-1),respectively. The rabbits in sham group did not re-ceive RAP and drugs. Electrophysiological examination was performed to test heart rate, P-wave duration, atrial effective refractory period (AERP) and AF inducibility. The protein expression levels of Cav1.2, Kv4.3 and myeloperoxidase (MPO) were detected by Western blot. RESULTS:Sustained AF was induced in 5 and 4 rabbilts in model group and atorvastatin group and no rabbits in sham group was found. After 3 weeks of RAP, compared with sham group, heart rate and P-wave duration were increased and AERP was shortened in model group and ATO group(P<0.05). Compared with model group,AERP was increased in ATO group(P<0.05),while heart rate and P-wave duration had no difference be-tween these 2 groups. Compared with sham group, the protein levels of Cav1.2 and Kv4.3 were decreased, and protein level of MPO was increased in model group and ATO group (P<0.05). Compared with model group, Cav1.2 was in-creased and MPO was decreased in ATO group(P<0.05),while Kv4.3 had no difference between these 2 groups. CON-CLUSION:Atorvastatin suppresses the down-regulation of atrial Cav1.2 protein level and the shortening of AERP, thus preventing atrial electrical remodeling in a rabbit model of chronic AF. The effect of atrovastatin on reducing atrial MPO level may be the potential mechanism.
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Objective Use McGurk effect paradigm materials to explore the role of lip-Reading for hearing-impaired children in phonetic identification.Methods Thirty-six severe prelingually hearing-impaired children and thirty-six normal healthy children(binaural PTA≤20 dB HL)were recruited in the study.The test material was composed of audio and video,including/ba/,/da/,/bi/,/di/,/bu/,/du/six stimulation sounds which were video recorded as pronounced.Under 3 different conditions,the two groups were evaluated for the accuracy of audi-tory responses.Results The accuracy of auditory responses of hearing-impaired children group was 0.71 ±0.19, 0.96±0.07,0.11 ±0.16 for auditory-only mode,audio -visual consistent mode and audio -visual inconsistent mode,respectively,0.93±0.10,0.96±0.11,0.54±0.23 for normal hearing children in auditory-only mode,audi-o-visual consistent mode and audio-visual inconsistent mode,respectively.Conclusion The Audio-visual con-sistent mode is the best one and the lip-reading can help hearing-impaired children in phonetic identification.
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OBJECTIVE@#To evaluate and compare outcomes effects of Chinese recognition materials in post-lingually deafened patients with cochlear implant.@*METHOD@#Thirty-two post-lingually deafened cochlear implant users participated in the study. Each one of them was given a series of speech recognition tests including the speech recognition score of monosyllable words, spondee words, Chinese BKB sentences and MHINT in quiet, as well as speech recognition threshold of HOPE corpus in babble noise. Speech recognition scores and thresholds were compared among these test materials using histograms , scatter diagrams and statistical methods.@*RESULT@#Recognition scores for spondee words, Chinese BKB sentences and MHINT were affected by ceiling effects, with 1,14 and 4 cases scored 100% respectivelty. Meanwhile, 17, 26 and 14 cases scored more than 85% correspondingly. On the other hand, speech recognition scores for monosyllable words in quiet and speech recognition threshold for HOPE corpus in babble noise were not affected.@*CONCLUSION@#For a considerable part of post-lingually deafened patients using cochlear implant, some Chinese speech recognition materials have demonstrated different degrees of ceiling effects. While speech recognition scores for monosyllable words in quiet and recognition threshold for HOPE corpus in noise can evaluate the performance of speech recognition abilitymore objectively.
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Humans , Cochlear Implantation , Cochlear Implants , Language , Noise , Speech Perception , Treatment OutcomeABSTRACT
Objective Although the correlation between high risk human papilloma virus (hrHPV) infection and cervical cancer ( CC ) or cervical intraepithelial neoplasia ( CIN ) is well known , vaginal cancer ( VC ) or vaginal intraepithelial neoplasia ( VAIN) also caused by hrHPV has not received enough attention .This article aims to explore the clinical characteristics of VC or VAIN after operations of CC or CIN in order to provide evidence for the treatment of these diseases . Methods The clinical charac-teristics and treatment of 15 cases with VC or VAIN after operations of CC or CIN were reviewed from Jan 2010 to May 2013 in our hos-pital. Results The mean age was (53.6 ±10.82) years, ranged from 39 to 73 years.The duration from the first operation to devel-oped VAIN or VC was (25.07 ±18.31) months, ranged from 1 to 60 months.There are 4 cases developed VC, 4 cases VAINⅢand 2 cases VINⅡfrom 10 CC patients;and 3 cases developed VC , 2 cases VAINⅢfrom 5 CINⅢpatients.hrHPV test were positive in all 15 patients.Treatment in these series were performed including total vaginectomy in 8 patients (3 VC, 4 VAINⅢ and 1 VAINⅡpatients), pelvic lymphonectomy in 1;upper vaginectomy in 2 patients (1 VC, 1 VAINⅢ), radiation or chemo-radiation therapy in 3 (3 VC), interferon muscle injection combined with topical application of estrogen and acyclovir gel in 2 (1 VC, 1 VAINⅡ). Conclusion Careful follow-up after CC or CIN operations are very important because continued hrHPV infection may result VC and VAIN lesions.Vaginectomy may be the best therapy .Interferon muscle injection combined with topical application of estrogen and acyclovir gel are also alternatively therapy , especially for hard to operate patients . Radiation therapy seems to be not very adaptable for VAIN patients .
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<p><b>OBJECTIVE</b>To investigate whether ω-6 polyunsaturated fatty acid promotes colon carcinogenesis through downregulation of P53-dependent growth inhibition.</p><p><b>METHODS</b>Colon carcinogenesis was induced by injection of azoxymethane (AOM) intraperitoneally. Experimental animals were randomly divided into four groups, receiving regular diet and intraperitoneal injection of normal saline(control group), high ω-6 polyunsaturated fatty acid diet with intraperitoneal injection of normal saline(Corn oil group), regular diet with intraperitoneal injection of AOM(AOM group), or high ω-6 polyunsaturated fatty acid diet with intraperitoneal injection of AOM (Corn oil+AOM group). Aberrant crypt focis (ACFs) were observed after methylene blue staining and enumerated. Colonic mucosa PCNA and P53 expressions were assessed by RT-PCR and Western blotting, and location of P53 in the colon crypt focis was determined by immunohistochemical staining.</p><p><b>RESULTS</b>Amounts of ACFs was 1.2±0.3 in the control group, 1.3±0.4 in the Corn oil group, 41.0±4.8 in the AOM group, and 73.3±9.9 in the Corn oil+AOM group, the differences were statistically significant(P<0.05). The expression of P53 in normal crypt focis was higher than that in ACFs. High ω-6 polyunsaturated fatty acid dietary significantly promoted AOM-induced colon PCNA expression, and enhanced AOM-mediated P53 inhibition in colon mucosa.</p><p><b>CONCLUSION</b>High ω-6 polyunsaturated fatty acid diet can enhance AOM-induced inhibition of P53 in colon mucosa, resulting in overexpression of PCNA, formation of ACF, and carcinogenesis in the colon.</p>
Subject(s)
Animals , Male , Rats , Colon , Metabolism , Fatty Acids, Unsaturated , Intestinal Mucosa , Metabolism , Proliferating Cell Nuclear Antigen , Metabolism , Rats, Sprague-Dawley , Tumor Suppressor Protein p53 , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To investigate the possibility of transdifferentiation of adipose mesenchymal stem cells (AMSCs) into hepatocytes.</p><p><b>METHODS</b>Human omentum adipose tissue was dispersed with collagenase I. Cells collected were cultured in a DMEM-F12 medium containing 2% FBS supplemented with 20 ng/ml HGF, 10 ng/ml FGF4, 1xITS and 0.1 micromol/L dexasmison. The cells of the control group were also cultured in the same kind of medium but without any cytokines serving as a control. The expression of hepatic transcriptional factors such as GATA4 and HNF1 were checked by RT-PCR. At the end of the induction, hepatocyte markers were analysed by flow cytometry, and cytokeratin expressions were examined using cyto-immunofluorescence methods.</p><p><b>RESULTS</b>AMSCs grew like fibroblasts and were passaged easily. Most of the third passaged AMSCs were positive against anti-CD29, anti-CD44 antibodies, but negative for the anti-CD34 and anti-CD45 ones. The hepatic transcriptional factor was expressed gradually to higher levels during the induction time. AFP and Alb positive cells were 30.0% and 17.8% of the total cultured cells, and the rate of cells positive to the two markers was 6.9%. The inducted cells were positive for CK18 and CK19 antibodies at the end of the induction. The cells in the control group were negative when checked by these methods.</p><p><b>CONCLUSIONS</b>AMSCs could be directed to differentiate into hepatocytes in vitro by a cytokine cocktail with a low concentration FBS culture system.</p>
Subject(s)
Humans , Adipocytes , Cell Biology , Cell Differentiation , Cell Transdifferentiation , Cells, Cultured , Hepatocytes , Cell Biology , Mesenchymal Stem Cells , Cell BiologyABSTRACT
<p><b>OBJECTIVE</b>To explore the possible mechanism of cyclovirobuxine D (CVB-D) in countering and inducing arrhythmia, by way of studying its electro-physiological effect on ventricular papillary muscles of rats in vitro.</p><p><b>METHODS</b>The transmembrane potential of rat's isolated right ventricular papillary muscles were recorded using conventional glass micro-electrode technique.</p><p><b>RESULTS</b>(1) CVB-D in concentration of 13.3-63.3 micromol/L, showed prolonging effect on the action potential repolarization time, mainly the action potential duration 50 (APD50), APD70 and APD90, in dose-dependent manner, in concentration of 33.3-63.3 micromol/L, it could inhibit the resting potential, action potential amplitude (APA) and maximum depolarization velocity (Vmax) in dose-dependent manner. (2) CVB-D also showed time-dependent effect, the effect initiated 10 min after 20 micromol/L was perfused in ventricular muscle, the APD50, APD70 and APD90 were potentiated gradually along with prolongation of action time and reached the peak at 30-40 min, without any potentiation thereafter. (3) CVB-D could markedly prolong the effective refractory period (ERP) of action potential, increase the ratio of ERP/APD. (4) CVB-D in concentration of 33.3 micromol/L could induce frequent, multifocal spontaneous arrhythmia in some cells when the action time was longer than 45 min.</p><p><b>CONCLUSION</b>CVB-D has the action of anti-ventricular arrhythmia, the mechanism is correlated with the prolongation of APD and ERP of ventricular muscle as well as the increase of ERP/APD ratio, while it also has the effect of inducing arrhythmia, the mechanism might be concerned with excessive prolongation of APD and the inhibition on RP, APA and Vmax.</p>