Selective Activation of Nociceptor TRPV1 Channel and Reversal of Inflammatory Pain in Mice by a Novel Coumarin Derivative Muralatin L from Murraya alata.

Coumarin and its derivatives are fragrant natural compounds isolated from the genus Murraya that are flowering plants widely distributed in East Asia, Australia, and the Pacific Islands. Murraya plants have been widely used as medicinal herbs for relief of pain, such as headache, rheumatic pain, toothache, and snake bites. However, little is known about their analgesic components and the molecular mechanism underlying pain relief. Here, we report the bioassay-guided fractionation and identification of a novel coumarin derivative, named muralatin L, that can specifically activate the nociceptor transient receptor potential vanilloid 1 (TRPV1) channel and reverse the inflammatory pain in mice through channel desensitization. Muralatin L was identified from the active extract of Murraya alata against TRPV1 transiently expressed in HEK-293T cells in fluorescent calcium FlexStation assay. Activation of TRPV1 current by muralatin L and its selectivity were further confirmed by whole-cell patch clamp recordings of TRPV1-expressing HEK-293T cells and dorsal root ganglion neurons isolated from mice. Furthermore, muralatin L could reverse inflammatory pain induced by formalin and acetic acid in mice but not in TRPV1 knock-out mice. Taken together, our findings show that muralatin L specifically activates TRPV1 and reverses inflammatory pain, thus highlighting the potential of coumarin derivatives from Murraya plants for pharmaceutical and medicinal applications such as pain therapy.

Simulation and evaluation of tablet-coating burst based on finite element method.

The objective of this study was to simulate and evaluate the burst behavior of coated tablets. Three-dimensional finite element models of tablet-coating were established using software ANSYS. Swelling pressure of cores was measured by a self-made device and applied at the internal surface of the models. Mechanical properties of the polymer film were determined using a texture analyzer and applied as material properties of the models. The resulted finite element models were validated by experimental data. The validated models were used to assess the factors those influenced burst behavior and predict the coating burst behavior. The simulation results of coating burst and failure location were strongly matched with the experimental data. It was found that internal swelling pressure, inside corner radius and corner thickness were three main factors controlling the stress distribution and burst behavior. Based on the linear relationship between the internal pressure and the maximum principle stress on coating, burst pressure of coatings was calculated and used to predict the burst behavior. This study demonstrated that burst behavior of coated tablets could be simulated and evaluated by finite element method.

Site-specific chemical modification of human serum albumin with polyethylene glycol prolongs half-life and improves intravascular retention in mice.

Human serum albumin (HSA) is used as an important plasma volume expander in clinical practice. However, the infused HSA may extravasate into the interstitial space and induce peripheral edema in treating the critical illness related to marked increase in capillary permeability. Such poor intravascular retention also demands a frequent administration of HSA. We hypothesize that increasing the molecular weight of HSA by PEGylation may be a potential approach to decrease capillary permeability of HSA. In the present study, HSA was PEGylated in a site-specific manner and the PEGylated HSA carrying one chain of polyethylene glycol (PEG) (20 kDa) per HSA molecule was obtained. The purity, PEGylated site and secondary structure of the modified protein were characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), thiol group blockage method and circular dichroism (CD) measurement, respectively. In addition, the pharmacokinetics in normal mice was investigated, vascular permeability of the PEGylated HSA was evaluated in lipopolysaccharide (LPS)-induced lung injury mouse model and the pharmacodynamics was investigated in LPS-induced sepsis model with systemic capillary leakage. The results showed that the biological half-life of the modified HSA was approximately 2.3 times of that of the native HSA, PEG-HSA had a lower vascular permeability and better recovery in blood pressure and haemodilution was observed in rats treated with PEG-HSA. From the results it can be inferred that the chemically well-defined and molecularly homogeneous PEGylated HSA is superior to HSA in treating capillary permeability increase related illness because of its longer biological half-life and lower vascular permeability.

Treating human meniscal fibrochondrocytes with hIGF-1 gene by liposome.

The menisci are intraarticular fibrocartilaginous structures essential to the normal function of the knee that lack the ability to self-repair. Human meniscal fibrochondrocytes may respond to beneficial genes like human insulin growth factor-1 (hIGF-1) and the meniscal cell may be a feasible donor for gene therapy. To explore this possibility, we amplified the hIGF-1 gene sequence in full length and cloned it into a bicistronic plasmid. This gene was then transfected into cultured human meniscal fibrochondrocytes by the liposome FuGene 6. Green fluorescence was expressed in part of the cells 6 hours after transfection and increased gradually, with a peak concentration of the hIGF-1 in the supernatants to 22.68 ng/mL 56 hours after transfection. Phenotypes of some cells changed and the proliferation accelerated after transfection. Flow cytometry analysis demonstrated upregulation of cell numbers in the G2 and S stages after hIGF-1 gene introduction. We conclude the hIGF-1 gene can be transfected into the human meniscal cell efficiently by liposome and it causes accelerated proliferation and differentiation. Within 10 days after transfection, the cytokine appears to be secreted into supernatants with the bioactivity and promotes the proliferation of the NIH 3T3 cell line.

Comparing vaginal tape and transobturator tape for the treatment of mild and moderate stress incontinence.

OBJECTIVE: To compare the efficacy and safety of the tension-free vaginal tape (TVT) and transobturator suburethral tape (TVT-O) procedures for the treatment of mild and moderate stress urinary incontinence (SUI). METHODS: A total of 56 women were randomly selected to undergo the TVT-O or the TVT procedure. In some patients, vaginal repair or vaginal hysterectomy was done simultaneously for associated indications. RESULTS: Mean blood loss and hospital stay duration were the same for the 2 groups, but mean +/- SD operative time was significantly shorter in the TVT-O than in the TVT group (16+/-4 min vs 27+/-6 min; P<0.001). On the second day following surgery a residual urine volume less than 100 mL was noted in 86% and 89% of the patients in the TVT-O and TVT groups, respectively; cure was achieved in 92.9% and 92.6% of the patients. No serious complications occurred in either group. Outcome was subjectively assessed, with the patients followed-up for a mean of 27.6 months. CONCLUSION: No significant differences in rates of cure, postoperative urine retention, or operative complications were found following the TVT-O or the TVT procedure.

Health safety of main water pipe materials supplied in China market.

OBJECTIVE: To assess the health safety of copper, steel and plastic water pipes by field water quality investigations. METHODS: Four consumers were randomly selected for each type of water pipes. Two consumers of every type of the water pipes had used the water pipes for more than 1 year and the other 2 consumers had used the water pipes for less than 3 months. The terminal volume of tap water in copper and steel water pipes should be not less than 0.1 liter, whereas that in plastic water pipes should be not less than 1 liter. RESULTS: The mean values of the experimental results in the second field water quality investigation of the copper and steel water pipes met the Sanitary Standards for Drinking Water Quality. The items of water sample of the plastic water pipes met the requirements of the Sanitary Standards for Drinking Water Quality. CONCLUSION: Copper, steel, and plastic pipes can be used as drinking water pipes.

[Study of the root canal characteristics of mandibular central incisors in 150 patients using cone-beam computed tomography].

PURPOSE: To investigate the root canal characteristics of mandibular central incisors using a cone-beam computed tomography (CBCT) technique. METHODS: One hundred and fifty patients (79 males and 71 females) receiving CBCT scan at Shanghai Ninth People's Hospital were recruited into this study. A total of 295 image samples of mandibular central incisors were obtained and analyzed in terms of the number and type of root canals. RESULTS: The majority of mandibular central incisors had a single canal (61% possessed a Type I canal system). Although 39% of the roots possessed two canals, only 8.8%had two separate apical foramina. CONCLUSIONS: The prevalence of two canals of mandibular central incisors in this case series was 39% and is within the range reported by previous studies on case series of different racial origin.

[Comparison of three kinds of root canal disinfection medications in treatment of chronic apical periodontitis with fistula].

PURPOSE: To evaluate Vitapex paste, calcium hydroxide paste and paper points of povidone iodine as medications of root canal disinfection and their abilities of pain control in treatment of chronic apical periodontitis with fistula. METHODS: A total of 90 patients of chronic apical periodontitis with fistula were randomly assigned to 3 groups,30 patients in each group. After regular root canal preparation, group 1 was given Vitapex paste, group 2 was given calcium hydroxide paste, and group 3 was given paper points of povidone iodine as medications of root canal disinfection. Visual analogue scales of pain were given to the patients and method of filling the scale was also introduced to them at the same time. The scales were taken back one week later. Both the data of the scales and the effects of root canal disinfection were recorded and analyzed. All statistical analysis was performed using SPSS 17.0 software package. RESULTS: The effect of root canal disinfection had no significant difference among the three groups. Group 1 achieved better result of pain control than the others. CONCLUSIONS: The three root canal disinfection medications are effective in treatment of chronic apical periodontitis with fistula. Vitapex paste is better for controlling the pain after root canal preparation than culcium hydroxide and paper points of povidone iodine.

[Clinical effect of three kinds of rotary nickel-titanium instruments on root canal preparation of molars].

PURPOSE: To evaluate three kinds of nickel-titanium instruments applied to molar root canal preparation. METHODS: A total of 90 molars treated by root canal therapy were randomly assigned to three groups: ProTaper group. K3 group and Mtwo group. Crown-down technique was used in ProTaper and K3 group, while Mtwo group was treated with routine preparation technique. All teeth in 3 groups were filled by lateral condensation technique. Treatment effect of 3 groups was evaluated according to pre- and post-operative X-ray films. Wearing and tearing degree of equipment, preparation time and postoperative complications incidence of 3 groups were also compared. All statistical analysis was performed using SAS9.0 software package. Data of root canal curvatures and preparation time was compared using t test; the incidence of complications of root canal treatment and postoperative pain was analyzed using Chi-square test. RESULTS: In three groups, root canals had no deviation or no ledge, could maintain the root canal anatomy in early form, and achieved good preparation results. In this study, four ProTapers, three K3s and one Mtwo instrument were fractured. The average root canal preparation time of the Mtwo group was 3.94 min, significantly less than the ProTaper (4.71 min) group and the K3(4.58 min) group. CONCLUSIONS: Three rotary nickel-titanium systems tested in this study are effective in the molar root canal preparation. The Mtwo instrument is much easier and faster during preparation with routine preparation technique.Supported by Research Fund of Science and Technology Commission of Shanghai Municipality(Grant No.08DZ2271100).

[Evaluation of X-ray beam angulation for successful four canals identification in the mandibular first molars].

PURPOSE: This study was aimed to determine the most effective horizontal beam angulation to identify 4 canals in the mandibular first molars, so as to provide full and accurate information for the clinic. METHODS: One hundred and twenty mandibular first molars with four canals that needed endodontic treatment in vivo were selected. Radiographs were taken at horizontal angles of 0,10,20 degrees from distal direction and 0,10,20,30 degrees from mesial direction of the tooth. The numbers of root canal and the degree of resolution were identified and recorded by 3 independent observers. Data were analyzed using SPSS10.0 software package or Chi-square test. RESULTS: At 30 and 20 degrees from mesial direction, 93.3% and 90.0% of all the 120 teeth were correctly identified as 4 canals, compared with 0 degree of 40.0%(P<0.01). Of them, 71.5% and 89.7% could be classified as with high resolution, respectively. The latter was not significantly lower than 0 degree of 95.0% (P>0.05). CONCLUSION: Twenty degrees from mesial direction is the most effective X-ray beam angle in diagnosing 4 canals of the first mandibular molars. Supported by Research Fund of Science and Technology Commission of Shanghai Municipality (Grant No.08DZ2271100).

[Analysis and countermeasure of dental graduates' psychological state].

PURPOSE: To study the dental graduates' psychological state in general dentistry and help teachers take countermeasure during clinical teaching. METHODS: 43 dental graduates were investigated in August 2008 through questionnaire, involving attitude toward career, communication in practice and so on. RESULTS: 46.51% of dental students felt optimistic about their occupation foreground, 72.09% of dental students wished be a dentist after graduation, 60.47% students felt indecisive in practice, 69.77% of students thought the preclinical theoretical study was partly useful in the practice, 65.12% of students could communicate with patients successfully. CONCLUSIONS: The dental graduates have ambivalence in profession ideal and actuality, such as conflict between work enthusiasm and work ability, communion need and obstacle. The teachers should try to intercommunicate with students,adopt corresponding psychotherapy individually,alleviate their stress,help them complete the dental practice well.

[The use of 1% dyclonine and local cryoanesthesia plus pulp vitality test agent in taking dental X-ray film].

PURPOSE: To analyze the effect of topical anesthetics in taking dental X-ray film. METHODS: 300 patients, who needed to take dental X-ray photography of maxillary or mandibular molar were randomly assigned to 3 groups. Bisecting angle technique was used to take the film. Before taking the X-ray, the throats of the patients in Group I were treated by 1% dyclonine spraying anesthesia, Group II were treated by FRILJET local cryoanesthesia and pulp vitality test agent, and Group III were set as control. The anesthesia efficiency and imagine quality of the dental films were evaluated, and the anesthetic time was recorded. The data was analyzed with ANOVA and Chi-square test using SPSS12.2 software package. RESULTS: The anesthesia efficiency was 99% in group I, 98% in Group II, and 62% in Group III. The imagine quality in Group I and II was higher than that in Group III. For both anesthesia efficiency and imagine quality, there was no significant difference between Group I and Group II, but there was significant difference between Group I and Group III, and between Group II and Group III (P<0.01).Significant difference of anesthetic time was showed between Group I and Group II . Compared with Group II, longer time(4 minutes) was needed in Group I to show the anesthetic effect, and it lasted longer for 21.62+/-3.54 minutes; while in Group II, the anesthetic effect lasted shorter, only for 2.07+/-1.22 minutes, but it developed immediately. CONCLUSION: The use of local anesthetics improves the accuracy, quality, and success rate in taking dental X-ray films.

Structural transformation and aggregation of human alpha-synuclein in trifluoroethanol: non-amyloid component sequence is essential and beta-sheet formation is prerequisite to aggregation.

Amyloid-like aggregation of alpha-synuclein and deposit in Lewy bodies are thought to be the major cause of Parkinson's disease. Here we describe the secondary structural transformation and aggregation of human alpha-synuclein and its C-terminus truncated fragments in trifluoroethanol. Proteins containing the NAC (non-amyloid component) segment undergo a three-state transition: from native random coil to beta-sheet and to alpha-helical structure, while the NAC deficient fragment and gamma-synuclein undergo a typical two-state coil-to-alpha transition. The beta-sheet form is highly hydrophobic that strongly binds to 1-anilinonaphthalene-8-sulfonic acid (ANS) and is prone to self-aggregation. The results suggest that the NAC sequence is essential to beta-sheet formation and the aggregation originates from the beta-sheet intermediate, which may be implicated in the pathogenesis of Parkinson's disease.