Objective To investigate the regulatory actions of Intestines-unblocking, Turbid-purging Recipe (ITR) on colonic 5-hydroxytryptamine (5-HT) and its receptor 5-hydroxytryptamine 3 (5-HT3) in rats with constipation-dominant irritable bowel syndrome (IBS-C), and to explore the therapeutic mechanism of ITR in treating IBS-C. Methods Forty-two male SD rats were randomly divided into 6 groups, namely normal group, model group, western medicine group, high-, middle- and low-dose Chinese medicine groups, 7 rats in each group. IBS-C rat model was established by intragastric administration of ice water. After establishment of the model, western medicine group was given intragastric administration of Cisapride Tablets (at the dosage of 3.6 mg·kg-1·d-1), Chinese medicine groups were given intragastric administration of various dosages of ITR granules (18.5, 9.25, 4.625 g·kg-1·d-1 respectively) , and the model group was given intragastric administration of normal saline, the treatment lasting 14 d. The rats in various groups were given normal feeding and drinking. After treatment, HE staining method was used to observe pathological changes in the intestinal tissue, immunohistochemistry method was used to observe the expression levels of intestinal 5-HT and 5-HT3 receptor. Results Compared with the normal group, the expression level of rat intestinal 5-HT was increased (P < 0.05) and that of 5-HT3 receptor was decreased (P < 0.05) in the model group and the medication groups. Compared with the model group, 5-HT expression level was decreased significantly (P<0.05) and 5-HT3 receptor expression level was increased (P < 0.05) in the medication groups, and the improvement of the middle-dose Chinese medicine group was more obvious (P < 0.05). Conclusion ITR has therapeutic efficacy for IBS-C rats through lowering 5-HT expression and increasing 5-HT3 receptor expression, which results into the improvement of intestinal sensitivity and abnormal dynamic of the rats.

AIM: To observe the effect of pigment epithelium-derived factor(PEDF)on retinal neovascularization(RNV)and monocyte chemoattractant protein-1(MCP-1)expressions in mice retina of oxygen-induced retinopathy(OIR), and to investigate the protective effect of PEDF on ischemia hypoxia retinopathy and the possible mechanism.

METHODS: A total of 160 postnatal day(P)7 C57BL/6 mice were obtained. All mice except normal control group were exposed to(75±2)% oxygen environment for 5d and then kept in room air for another 5d to establish the OIR mice model. All mice in normal control group(40 mice)were exposed to room air only. At P12 and P14, respectively, mice in PEDF treatment group were injected intravitreously with recombinant human PEDF(2μg/eye,1μL)in the right eye, while mice in treatment control group were injected intravitreously with the same volume of vehicle [1μL, 10mmol/L phosphate buffered saline(PH7.4), PBS] in the right eye. All mice were euthanized at P17. Eyes were whole mounted and stained with Lectin to observe the growth of abnormal RNV; And retinal specimens were prepared for PEDF, MCP-1 protein and mRNA analysis by Western blot and real time RT-PCR respectively.

RESULTS: Changes of retinal vessels had been detected by fluorescence microscopy on flat-mounted retina. The relative RNV areas were significantly increased in OIR model group compared with those in normal control group(P<0.01). However, the relative RNV areas were significantly reduced in PEDF treatment group compared with those in PBS treatment control group(P<0.01). The specific expression of MCP-1 protein and mRNA in the OIR model group were higher than those of normal control group, presenting a statistically significance(both P<0.05). The specific expression of PEDF protein and mRNA in the OIR model group showed a considerable decline in comparison with normal control group, presenting a statistically significance(both P<0.01). And the specific expression of MCP-1 protein and mRNA in those of PEDF-treated group showed a considerable decline in comparison with PBS-treated group, and the differences were statistically significant(both P<0.05). However, there were increase of the expression of MCP-1 protein and mRNA between normal control group and PEDF-treated group, presenting no statistically significance(both P>0.05).

CONCLUSION: PEDF could inhibit oxygen-induced retinal neovascularization and down-regulate retinal MCP-1 expression under hypoxia, which may underlie its anti-neovascularization effects and play a role of protection in ischemic retinopathy.

BACKGROUND: Most studies suggest tooth whitening can create a coarse enamel surface which is likely to attract exogenous dyeing material and form the phenomenon of color relapse. After dental bleaching procedure, the use of resin surface treatment agent is expected to make the enamel surface smooth and alleviate tooth color relapse. OBJECTIVE: To unravel the efficacy of Adper Single Bond 2 Adhesive on color relapse phenomenon after dental bleaching treatment by cold light (xenon laser) whitening.METHODS: Twenty-four extracted teeth were collected and coated with 35% hydrogen peroxide followed by xenon laser whitening. The test group was made up of 12 samples coated with light-cured resin surface treatment agent and the left samples as control group were treated with no-coating agent after tooth whitening. Then the two groups were divided into two subgroups which were soaked in distilled water and tea for aging test respectively. The color differences (ΔE) which provided comparative values for statistical analysis was recorded at 1, 3, 5, 7, 14, 21, 28, 35 and 42 days after the aging test. The enamel surface microstructure of the samples was observed before and after bleaching, after resin agent coating, and 28 days after the aging test.RESULTS AND CONCLUSION: (1) Results from color differences observation: there was no significant difference between samples soaked in distilled water before and after whitening treatment (P > 0.05). Similarly, there was no statistical difference between test group and control group soaked in distilled water (P > 0.05). However, after soaking in tea, the color differences in the test group at 1-42 days showed statistically significant differences from those in the control group (P < 0.05). (2) Results from scanning electron microscope observation: after the tooth whitening producers, the enamel surface was damaged in the presence of cavities. After coated with resin surface treatment agent, the enamel surface became smooth and had few cavities. After soaking in tea, gradient smooth surface, some crack, inconspicuous flake dyeing color layer decomposition could be seen in the test group while rough surface with big holes and mottled dyeing layer were clearly visible in the control group. All samples soaked in distilled water had only a small amount of block dyeing layer, holes, weaker roughness than those soaked in tea. To conclude, Adper Single Bond 2 Adhesive light-cured resin surface treatment agent could weaken color relapse phenomenon after tooth whitening, achieving a smooth enamel surface and reducing dyeing material adhesion.

BACKGROUND: As a special source of stem cells, dental pulp stem cells (DPSCs) make much progress in the development of tissue engineering field due to their high proliferation and self-renewal ability. In the certain conditions DPSCs can be induced to differentiate into a variety of specialized tissue cells, providing a new way for tissue engineering development. OBJECTIVE: To review the main progress in the DPSCs biological characteristics, original source, isolation method, and its related application in tissue engineering research. METHODS: "Dental pulp stem cell, differentiation, regenerative medicine, tissue engineering" in English and Chinese were termed as the keywords to search relevant articles about DPSCs and tissue engineering published from 2005 to 2017 in PubMed, Medline, WanFang, and CNKI databases. After removal of repetitive or irrelevant articles, 66 articles were finally reviewed. RESULTS AND CONCLUSION: With the development of tissue engineering and regenerative medicine, the effective combination of DPSCs and tissue engineering scaffolds have be further achieved. Recent studies on DPSCs focus on the properties of DPSCs differentiating into odontoblasts and osteocytes/osteoblasts and on the potential of nerve repair, vascular remodeling, corneal reconstruction and chondrogenic differentiation.

Trace elements (TEs), also known as micronutrients in biology, are trace components required by the human body, accounting for 0.005% to 0.01% of body weight. Although TEs are present in small quantities in the human body, they play significant roles in cellular metabolism, enzyme activity regulation, immune function, nerve conduction, and bone health. In this review, the effects of TEs (zinc, iron, magnesium, selenium, copper, chromium, and manganese) for modulating biological functions on organisms are comprehensively analyzed and summarized. The mechanisms of various TEs in immune system, enzymatic reaction, oxidative stress, physical growth, and blood glucose regulation are deeply discussed, emphasizing the indispensable role of TEs in maintaining normal physiological functions of body. In addition, the future research directions of TEs are also prospected, including the mechanism of action, intake, metabolism, and storage of TEs at the cellular level. This review will provide useful information to further understand the biological effects and the application of TEs.

OBJECTIVE: Larotaxel is a new chemical structure drug, which has not been marketed worldwide. Accordingly, the standard identification and quantification methods for larotaxel remain unclear. The spectrometric analyses were performed for verifying weight molecular formula, molecular weight and chemical structure of larotaxel. Besides, a quantification method was developed for measuring larotaxel in the liposomes. METHODS: The molecular formula, molecular weight and chemical structure of larotaxel were studied by using mass spectrometry (MS), infra-red (IR), nuclear magnetic resonance (NMR) and ultraviolet-visible (UV-vis) spectrometric techniques. The absorption wavelength of larotaxel was investigated by UV-vis spectrophotometry full-wavelength scanning. Besides, a quantification method was developed by high performance liquid chromatography (HPLC), and then validated by measuring the encapsulation efficacy of larotaxel liposomes. RESULTS: The four spectral characteristics of larotaxel were revealed and the corresponding standard spectra were defined. It was confirmed that larotaxel had the structure of tricyclic diterpenoids, with the molecular formula of C45H53NO14, the molecular weight of 831.900 1, and the maximum absorption wavelength of 230 nm. The quantitative method of larotaxel was established by using HPLC with a reversed phase C18 column (5 μm, 250 mm×4.6 mm), a mobile phase of acetonitrile-water (75:25, volume/volume), and a detection wavelength of 230 nm. The validation study exhibited that the established HPLC method was stable, and had a high recovery and precision in the quantitative measurement of larotaxel in liposomes. In addition, a new kind of larotaxel liposomes was also successfully prepared. The particle size of the liposomes was about 105 nm, with an even size distribution. And the encapsulation efficiency of larotaxel in the liposomes was above 80%. CONCLUSION The present study offers reference standard spectra of larotaxel, including MS, IR, NMR, and UV-vis, and confirms the molecular formula, molecular weight and chemical structure of larotaxel. Besides, the study develops a rapid HPLC method for quality control of larotaxel liposomes.
Chromatography, High Pressure Liquid ; Liposomes ; Magnetic Resonance Spectroscopy ; Taxoids