Effect of Isodon ternifolius-medicated serum on hepatic stellate cells based on TLR4/NF-κB/NLRP3 signaling pathway / 中国中药杂志

The present study aimed to investigate the inhibitory effect and mechanism of Isodon terricolous-medicated serum on lipopolysaccharide(LPS)-induced hepatic stellate cell(HSC) activation. LPS-induced HSCs were divided into a blank control group, an LPS model group, a colchicine-medicated serum group, an LPS + blank serum group, an I. terricolous-medicated serum group, a Toll-like receptor 4(TLR4) blocker group, and a TLR4 blocker + I. terricolous-medicated serum group. HSC proliferation was detected by methyl thiazolyl tetrazolium(MTT) assay. Enzyme-linked immunosorbent assay(ELISA) was used to measure type Ⅰ collagen(COL Ⅰ), COL Ⅲ, transforming growth factor-β1(TGF-β1), intercellular adhesion molecule-1(ICAM-1), α-smooth muscle actin(α-SMA), vascular cell adhesion molecule-1(VCAM-1), cysteinyl aspartate-specific proteinase-1(caspase-1), and monocyte chemotactic protein-1(MCP-1). Real-time PCR(RT-PCR) was used to detect mRNA expression of TLR4, IκBα, and NOD-like receptor thermal protein domain associated protein 3(NLRP3), nuclear factor-κB(NF-κB) p65, gasdermin D(GSDMD), and apoptosis-associated speck-like protein containing a CARD(ASC) in HSCs. Western blot(WB) was used to detect the protein levels of TLR4, p-IκBα, NF-κB p65, NLRP3, ASC, and GSDMD in HSCs. The results showed that I. terricolous-medicated serum could inhibit the proliferation activity of HSCs and inhibit the secretion of COL Ⅰ, COL Ⅲ, α-SMA, TGF-β1, caspase-1, MCP-1, VCAM-1, and ICAM-1 in HSCs. Compared with the LPS model group, the I. terricolous-medicated serum group, the colchicine-medicated serum group, and the TLR4 blocker group showed down-regulated expression of p-IκBα, NLRP3, NF-κB p65, GSDMD, and ASC, and up-regulated expression of IκBα. Compared with the TLR4 blocker group, the TLR4 blocker + I. terricolous-medicated serum group showed decreased expression of TLR4, p-IκBα, NLRP3, NF-κB p65, GSDMD, and ASC, and increased expression of IκBα. In conclusion, I. terricolous-medicated serum down-regulates HSC activation by inhibiting the TLR4/NF-κB/NLRP3 signaling pathway.

Analysis on the application of infectious diseases automated-alert and response system in Tianjin during the 13th Five-Year Plan period / 公共卫生与预防医学

Objective To analyze the epidemiological characteristics of automatic warning signals of infectious diseases received in Tianjin during the 13th Five-Year Plan period, and to provide reference for the function optimization of automatic warning system of infectious diseases during the 14th Five-year Plan period． Methods The data of infectious disease automatic early warning signals in Tianjin from 2016 to 2020 were downloaded from the China infectious diseases automated-alert and response system (CIDARS). The characteristics and response of early warning signals were analyzed by descriptive method. Results During the 13th Five-Year Plan period, 23,660 early warning signals were received in Tianjin, involving 39 kinds of infectious diseases, with 100% response rate and 1.10% positive rate of early warning signals. The median response time of warning signal was 0.53 hours (P25-P75: 0.19-1.17h). 95.74% of signals were responded within 2 hours and 98.47% of signals were responded within 24 hours. COVID-19, other infectious diarrhea diseases, dysentery, measles, and scarlet fever were the top five diseases with early warning signals. Conclusion During the 13th Five-Year, the automatic early warning system of infectious diseases in Tianjin runs well and has a high response rate, but the positive rate of early warning signal is low. During the 14th Five-Year，further research is needed to improve the early warning threshold according to the prevention and control needs and epidemic characteristics of different diseases, and to improve early warning positive rate.

Correlation and Traditional Chinese Medicine Intervention of Pyroptosis and Liver Diseases / 中国实验方剂学杂志

Pyroptosis， also known as cell inflammatory necrosis， is different from apoptosis， necrosis， and other forms of cell death in morphological characteristics， occurrence， and regulatory mechanism. It is a new type of programmed cell death dependent on Caspase， which has been discovered and confirmed in recent years. Studies have shown that pyroptosis is closely related to the occurrence of liver diseases， and is critical in alcoholic liver disease （ALD）， non-alcoholic fatty liver disease （NAFLD）， liver fibrosis， and liver cancer. Pyroptosis causes inflammatory injury of hepatocytes to promote the occurrence and development of liver diseases by activating Caspase-1， cleaving the effector gasdermin-D （GSDMD）， and releasing pro-inflammatory cytokines， such as interleukin-18 （IL-18） and interleukin-1β （IL-1β） mainly through the classical NOD-like receptor protein 3 （NLRP3） inflammasome pathway. Clinically， Chinese medicine in the treatment of liver diseases has unique efficacy and low side effects. In the intervention on liver diseases， Chinese medicine blocks the pyroptosis signaling pathway to relieve the liver inflammation by inhibiting the assembly and activation of NLRP3 inflammasome multiprotein complex， blunting the activity of Caspase-1 or Caspase-4/Caspase-5/Caspase-11， and inhibiting the cleavage of GSDMD to reduce the release of pro-inflammatory cytokines such as IL-18 and IL-1β. Therefore， in-depth investigation of pyroptosis facilitates unveiling its role in the occurrence， development， and prognosis of liver diseases， and the enhancement or inhibition of pyroptosis may provide a new strategy for the prevention and treatment of liver diseases by Chinese medicine. At present， NLRP3 inflammasome， a key protein in the classic pyroptosis signaling pathway， has become an anti-liver disease target of Chinese medicine. This study briefly summarized the relationship between pyroptosis and liver diseases and reviewed the intervention of monomers， compound prescriptions， effective fractions and extracts of Chinese medicine in recent years to provide important guidance for further exploring the pathogenic mechanism of pyroptosis and the treatment of liver diseases with Chinese medicine.

Research Progress of Blood Brain Barrier Model and Effect of Traditional Chinese Medicine on Its Permeability / 中国实验方剂学杂志

Blood brain barrier (BBB), as barrier between plasma and brain cells formed by brain capillary wall and glial cells and barrier between plasma and cerebrospinal fluid formed by choroid plexus, can prevent some brain tissues (mostly harmful substances), so as to maintain a stable internal environment of brain tissues, while stopping most drugs from the intracranial and causeing difficulties to cerebral diseases. The establishment of experimental model of BBB is a key technique for drug treatment of craniocerebral diseases. Therefore, the establishment of the BBB model and the study of its permeability change will deepen the understanding of the neuro-vascular interaction and provide an important theoretical basis for the diagnosis and treatment of central nervous system diseases. Traditional Chinese medicine(TCM) can affect brain tissue superoxide dismutase (SOD) activity, inhibit myeloperoxidase (MPO) activity and tumor necrosis factor-α (TNF-α) content, so as to affect the expression of zonula occluden-1 (ZO-1) or up-regulate the expression of Claudin-5, inhibit BBB permeability under pathological conditions, and play a protective role in BBB. TCM can also promote the changes in BBB permeability by affecting the expressions of cell adhesion factor-1 (CAM-1), ZO-1, filamentous actin(F-actin), P-glycoprotein(P-gp)and 5-hydroxytryptamine (5-HT), or increase drug permeability through co-delivery with other drugs. In this paper, the methods, advantages and disadvantages of the establishment of experimental models of the BBB in recent years, as well as the effects of TCM monomers, effective components and TCM compounds on the permeability of the BBB were summarized, so as to provide important guidance and direction for the future treatment of intracranial diseases by traditional Chinese and western medicine.

Effect of Traditional Chinese Medicine on Hepatic Disease by Inhibiting TLR4 Signaling Pathway / 中国实验方剂学杂志

Liver disease is the general term for all diseases that occur in the liver. In recent years, traditional Chinese medicine has certain advantages in the treatment of liver diseases. With a high experimental study value, good clinical efficacy and less adverse reactions, it has broad prospects. Toll-like receptor 4 (TLR4) signaling pathway is closely related to liver diseases. Its mechanism is to activate nuclear factor-κB (NF-κB) through tlr4-mediated signaling pathway, inhibit the secretion of such inflammatory factors as interleukin-1(IL-1), interleukin-6(IL-6) and tumor necrosis factor-alpha (TNF-α), and the inflammatory damage of liver cells, so as to further inhibit the effect of IL-1,IL-6, TNF-α in activating Hepatic Stellate Cell(HSC). The ways of blocking TRL4 pathway are as follows:Inhibiting the expression of TLR4,Inhibiting the dimerization of TLR4. Blocking intracellular signal transduction:①acting on the binding protein; ②acting on the kinase IRAKs; ③acting on TLRAFst. In these ways, the TRL4 pathway is blocked, the inflammation is inhibited, and the anti-liver disease effect is achieved. Therefore, inhibiting or enhancing TLR4 signaling pathway or intervening in some links of TLR4 signaling pathway has become a new strategy for the treatment of liver diseases. Toll-like receptor 4 signaling pathway has become one of the targets of traditional Chinese medicine (TCM) against liver diseases. In this paper, the recent literatures on the effect of TCM in resisting activation of TLR4 signaling pathway and the effect of anti-liver diseases through monomers and effective parts of TCM, extracts of TCM and compound prescriptions of TCM were collected and summarized to provide important guiding significance and direction for the treatment of liver diseases by TCM and WM in the next step.

Effects of huai qi huang on cytokines Th1, Th2 and Th17 and phagocytosis of alveolar macrophages in rats with asthma / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the effects of huai qi huang, a traditional Chinese medicine, on cytokines Th1, Th2 and Th17 levels and alveolar macrophage phagocytosis in asthmatic rats sensitized by ovalbumin (OVA).</p><p><b>METHODS</b>Forty male Sprague-Dawley rats were randomly divided into five groups: normal control, untreated asthma, budesonide-treated, huai qi huang-treated and budesonide+huai qi huang-treated asthma (n=8 each). Asthma was induced by OVA sensitization and challenge. The levels of IL-4, IFN-γ and IL-17 in plasma and bronchoalveolar lavage fluid (BALF) were measured using ELISA. The phagocytosis of alveolar macrophages which were isolated and purified from BALF was evaluated by the colorimetric assay.</p><p><b>RESULTS</b>The levels of IL-4 and IL-17 increased, in contrast, the IFN-γ level decreased in plasma and BALF in the untreated asthma group compared with those in the normal control group. The IFN-γ level in the huai qi huang-treated asthma group was higher than that in the untreated asthma group. The IFN-γ level increased and the IL-17 level decreased more significantly in the budesonide+huai qi huang-treated asthma group when compared with the budesonide and huai qi huang alone treatment groups. The phagocytosis of alveolar macrophages in the untreated asthma group was lower than that in the normal control group. Huai qi huang alone or combined with budesonide increased the phagocytosis of alveolar macrophages compared with the normal control, untreated asthma and budesonid-treated asthma groups. The levels of IFN-γ in plasma and BALF were positively correlated with the phagocytosis of alveolar macrophages.</p><p><b>CONCLUSIONS</b>The levels of IL-4 and IL-17 increase and the IFN-γ level decreases in plasma and BALF, and the phagocytosis of alveolar macrophages decreases in asthmatic rats. Huai qi huang treatment may increase the IFN-γ expression in plasma and BALF and the phagocytosis of alveolar macrophages in asthmatic rats. There is a synergistic effect between huai qi huang and glucocorticoids.</p>

Evaluation on repeat cesarean section of 67 cases / 中国基层医药

Objective To explore the complications and influence of repeat cesarean section after previous cesarean delivery. Methods The styles of the total 67 cases of repeat cesarean section were reviewed, and the mater-nal ages, gestarional weeks, time intervals between the two times of delivery, and the styles of the previous cesarean section were analyzed. Results Of the total 67 case of repeat cesarean section ,there were 8 cases with relatively se-vere adhesion, 1 case with hysterectomy. There were 9 cases with intraoperative blood loss over 500ml(13.4%). The rate of adhesion induced by abdominal transverse incision of cesarean section was significantly higher than that of ab-dominal longitudinal incision of low cesarean section. Conclusions When we determining a style of cesarean section, we should comprehensively consider the obstetrical conditions of the pregnant women to select abdominal incision style and uterine incision style. The quality of previous cesarean delivery determines the complications of repeat cesarean section.

Preliminary analysis of urinary proteomics in children with steroid-resistant and steroid-sensitive nephrotic syndrome / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study and identify the protein markers in the urine of children with steroid-sensitive (SSNS) and steroid-resistant nephrotic syndrome(SRNS).</p><p><b>METHODS</b>Total urinary proteins were extracted from children with SSNS before and after steroid therapy, SRNS, and healthy children (n=5 in each group). Urinary proteins were separated by immobilized pH gradient based on two-dimensional gel electrophoresis (2-DE). The silver-stained 2-DE gels were scanned with digital Image Scanner and analyzed with Image Master 2-DE Elite 3.01 software. Peptide mass fingerprint (PMF) of differential protein spots was obtained with MALDI-TOF-MS. Proteins were identified by Mascot software based on NCBI protein database.</p><p><b>RESULTS</b>There were 66 spots with different expression of protein between SRNS children and SSNS children before steroid therapy, and 24 spots and 27 spots only occurred in SRNS children and SSNS children before steroid therapy, respectively. There were 75 spots with different expression of protein between SSNS children after steroid therapy and healthy controls, and 11 spots only occurred in SSNS children after steroid therapy. Eighteen protein spots with different expression (6 spots in each nephrotic group) were chose and analyzed by MALDI-TOF-MS, and 9 types of proteins were identified.</p><p><b>CONCLUSIONS</b>Nine types of urinary proteins with different expression (6 spots in each nephrotic group) were identified between SRNS and SSNS children, and they might be the biomarkers for SRNS or SSNS.</p>

Family tree and restoration method of hereditary opalescent dentin: a case report / 华西口腔医学杂志

Hereditary opalescent dentin is a rare autosomal dominant inherited disease of dentin development. A case of hereditary opalescent dentin was reported, and the pathogenesis, family tree and restoration methods were reviewed.

Association among circulating endothelial progenitor cells, insulin resistance and severity of coronary lesions in patients with coronary artery disease / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the correlation between the number and activity of circulating endothelial progenitor cells (EPCs), insulin resistance and severity of coronary lesions in patients with coronary artery disease (CAD).</p><p><b>METHODS</b>Patients with coronary angiography evidenced CAD were divided in insulin resistance group (IR, n = 25) and insulin sensitive group (IS, n = 44) according to insulin level, 25 health volunteers served as control. Circulating EPCs were marked as KDR/CD133+ cells via fluorescence-activated cell sorter analysis. EPCs were also isolated from peripheral blood and cultured in vitro for 7 days, identified by DiI-acLDL uptake and lectin staining methods. EPCs migration activities were determined by modified Boyden chamber assay, EPCs proliferation activities were determined by MTT assay.</p><p><b>RESULT</b>Circulating EPCs number was significantly lower in IR group compared with IS group [(0.34 +/- 0.08) per thousand vs. (0.47 +/- 0.09) per thousand, P < 0.01] and control group (P < 0.05). Both insulin resistance index (r = -0.291, P = 0.01)and Gensini score (r = -0.3984, P = 0.006)were negatively correlated with number of circulating EPCs. Proliferation and migration capacities of EPCs were also significantly lower in IR group compared to those in IS group (all P < 0.05) and control group (all P < 0.05).</p><p><b>CONCLUSIONS</b>Insulin resistance/hyperinsulinemia could aggravate severity of coronary artery lesions via reducing the number and activities of circulating EPCs in patients with CAD.</p>

Effect of the thickness of periodontal ligament on the fracture resistance of root and post-core system / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To assess the effect of the thickness of periodontal ligament on the fracture resistance of root and post-core system.</p><p><b>METHODS</b>Forty-five simulated roots in the same length, taper and diameter were made of polymethacrylate (PMMA). Then the wax patterns of post-cores were cast. Soft lining material was used to simulated periodontal ligament. And each specimen was embedded in acrylic resin and then fixed in a special jig on the universal load-testing machine. A compressive load was applied at a 90-degree angle to the long axis of the core until fracture, at a crosshead speed of 1 mm/min. The maximum of load and the displacement were recorded.</p><p><b>RESULTS</b>The mean values of load in root and post-core system were 148.033 N, 161.889 N, 168.667 N, 181.589 N, 194.622 N, and the mean values of displacement were 1.965 mm, 2.837 mm, 3.327 mm, 3.927 mm, 5.326 mm.</p><p><b>CONCLUSION</b>The fracture resistance and displacement of root and post-core system with the same quality and altitude periodontal ligament are associated with the thickness of periodontal ligament when the range of thickness is from 0.2 mm to 1.0 mm.</p>

Effect of glucocorticoid receptor beta on glucocorticoid action in glomerular mesangial cells / 中南大学学报(医学版)

OBJECTIVE@#To construct mesangial cell lines over- or under- expressing glucocorticoid receptor beta (GRbeta), to investigate the effect of GRbeta on glucocorticoid biological function, and to determine whether the overexpression of GRbeta explains the glucocorticoid-resistant in glomerular mesangial cells (GMCs).@*METHODS@#The recombinant human sense or anti-sense gene of GRbeta was transferred into the rat GMCs by retrovirus-mediated stable transfection technique. Expression of hGRbeta mRNA in GMCs was determined by reverse transcription of total RNA followed by quantitative reverse transcription-polymerase chain reaction (RT-PCR), and the product of RT-PCR was then analyzed by gene sequencing. The expression of hGRbeta protein in GMCs was tested by Western blot. The inhibitory rate of dexamethasone-mediated cells on lipopolysaccharide (LPS)-stimulated GMC proliferation was detected to assess the effect of GRbeta at different expression levels on the glucocorticoid action. The cell proliferative activity in different cells with different levels of GRbeta was tested by MTT chromatometry. The change of cell cycle was analyzed by flow cytometry.@*RESULTS@#RT-PCR and gene sequencing showed that the recombinant sense and anti-sense genes were correctly integrated into genomic DNA of mesangial cells. The protein expression tested by Western blot showed that GRbeta in cells inserted with the sense hGRbeta gene was higher than those cells inserted with the anti-sense hGRbeta gene (109.74+/-10.63 vs. 19.08+/-1.01, P<0.05). The inhibitory rate of cell proliferation induced by dexamethasone was lower in GMCs transfected with sense hGRbeta gene than those transfected with anti-sense hGRbeta gene (18.47%+/-2.12% vs. 60.33%+/- 5.29%,P<0.05). Under the inhibition of dexamethasone, the decreased cell number of S-stage cells was significantly lower, and the increased cell number of G1- stage cells was significantly higher in GMCs transfected with sense hGRbeta gene than those of non-transfected cells.@*CONCLUSION@#The overexpression of GRbeta may inhibit the glucocorticoid action in GMCs. The GRbeta level in mesangial cells may be an important factor in determining whether they are sensitive or resistant to glucocorticoid.

Establishment of urinary proteomic map on two-dimensional polyacrylamide gel electrophoresis in children with idiopathic nephrotic syndrome / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To establish a urinary proteomic map on two-dimensional polyacrylamide gelelectrophoresis (2-DE) in children with idiopathic nephrotic syndrome (INS).</p><p><b>METHODS</b>The proteins from INS children were purified by four various means, separated by 2-DEand stained by silver.</p><p><b>RESULTS</b>The sequential preparation of urinary proteins by acetone precipitation and dislysis, when the sample was 300 microg, resulted in a clear background, well-resolved and reproducible 2-DE urinary protemic map in children with INS.</p><p><b>CONCLUSIONS</b>A steady 2-DE technique for urinary protemic map in children with INS was established, which can be effectively applied in urinary proteomics of the disease.</p>

Current Situation of Medical Education on Oncology in China / 中华医学教育探索杂志

Medical education on oncology is urgently enhanced in China.We analyse a host of questions in medical education on oncology in our country at present,and study didactical methods,goal and task on oncology education.

The role of cyclooxygenase on angiogenesis and endothelial progenitor cell mobilization in rat ischemic myocardium / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the effect of COX1 and COX2 on angiogenesis and endothelial progenitor cell mobilization in rats with experimental myocardial infarction (MI).</p><p><b>METHODS</b>The rats were randomly divided into 3 groups: MI group, MI plus rofecoxib group and MI plus valeryl salicylate group. At the 7th day after operation, circulating EPCs, plasma VEGF and HIF-1alpha mRNA of ischemic myocardium were measured. At the 28th day post operation, capillary densities were also measured in ischemic myocardium.</p><p><b>RESULT</b>Compared with the MI group and the MI plus valeryl salicylate group, circulating EPCs, plasma VEGF, HIF-1alpha mRNA and capillary densities of ischemic myocardium were all decreased in MI plus rofecoxib group.</p><p><b>CONCLUSION</b>The present study revealed that COX2 play an important role with angiogenesis and endothelial progenitor cell mobilization in rat with experimental MI by modulating expression of VEGF and HIF-1alpha.</p>

Sirolimus inhibits the differentiation, proliferation and migration of endothelial progenitor cells in vitro / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the effect of sirolimus on differentiation, proliferation, adhesion and migration of endothelial progenitor cells (EPC) in vitro.</p><p><b>METHODS</b>(1) Mononuclear cells (MNC) were isolated from rat bone marrow by Ficoll density gradient centrifugation and cultured on fibronectin-coated culture dishes with or without sirolimus (0.01 - 100 ng/ml) for 12 days. (2) After 8 days cultured, attached cells were treated with sirolimus (0.1 - 200 ng/ml) or vehicle for various time points (12 h, 24 h, 48 h and 96 h). EPC were identified as adherent cells double positive stained for FITC-UEA-I and DiI-acLDL under laser confocal immunofluence microscope. EPC proliferation, migration were assayed with MTT assay and modified Boyden chamber assay respectively.</p><p><b>RESULTS</b>EPC number differentiated from MNC at 12 days was significantly lower in sirolimus treated cells in a dose-dependent manner than that of vehicle-treated cells. Sirolimus also significantly inhibited the proliferative, migratory and adhesive capacity of EPC in a time and dose dependent manner.</p><p><b>CONCLUSION</b>Present results suggested that sirolimus could inhibit EPC differentiation from MNC and reduce the proliferation, migration and adhesion capacities of EPC.</p>

Influence of convergence angle on the retention of cast metal post and core restorations / 中国组织工程研究

BACKGROUND: The residual root of anterior teeth are usually repaired by means of post and cores plus porcelain fused metal crown in clinic, and the retention force is mainly provided by the post because of the deletion of crown, so the retention force provided by the post is directly correlated with the long-term effect of repair.OBJECTIVE: To analyze the changes of retention of cast metal post and core restorations with different convergence angles, and investigate the influence of convergence angles on retention.DESIGN: A repeated observational measurement.SETTING: Department of Prosthodontics, West China School of Stomatology, Sichuan University.MATERIALS: The experiments were carried out in the building of high polymer material of Sichuan University in May 2005. Fifty-four simulated tooth roots were manufactured by the numerical control machine tools.They were divided into six groups according to the convergence angles of post being 0°, 3.93°, 5.71°, 7.48°, 11.31° and 14.71°, with nine specimens in each group.METHODS: ① Manufacture of the standard specimens: The tooth roots with the convergence angles of 0°,3.93°, 5.71°, 7.48°, 11.31° and 14.71° were prepared with the digital control precision machine. ② Manufacture of the cast post and cores: The post and core wax patterns of the specimens were made in the condition similar to the clinical practice. The post and cores were cast and tried in, necessary grinding was made to ensure the adoption of the posts and the specimens. Then the posts were luted to the specimens with ZPC after the posts and the simulated root canals having een cleaned by alcohol. The posts and the specimens were pressed until the ZPC solidified. ③ Retention Force test: After having been dipped in physiological saline for 24 hours, the bonded castings and specimens were subjected to a tensile testing at the drawing speed of 10 mm per minute.The retention force of post was the load recorded when the post was pulled out from the specimen. ④ Planar bonding strength test: We cut a PMMA stick into the same little cylinders and made angular milling on the flank of the cylinders. The angle between the milled bevel and the central axis of the cylinder was controlled to 0°, 1.9°, 3°, 6°, 9°, 12° and 15°. Afterwards we cut the brass into pieces. Eight wafers were cast with the same diameter of 8 mm and thickness of 1 mm. With the same procedure of bonding the posts to specimens, the brass pieces were bonded to the cylinder bevels and the wafers were adhered to the upside of some unmachinized cylinders.Immerged in physiological saline for 24 hours, their bonding force were tested at the speed of 10 mm per minute, and the load was recorded when the pieces and wafers were separated from the cylinders. ⑤ Calculation of the frictional and interlocking forces: As the post can be regarded as a frustum, the bonding surface area can be calculated with the formula calculating the flank area of frustum, and the area of the occlusal bonding surface is the sum of the annulus part of the root surface and the circular part of the post tip. Some regressions were made to the retention force, frictional strength, bonding strength per unit area, retention force per unit area and frictional force per unit area to convergence angles.MAIN OUTCOME MEASURES: ① Bonding strength of different convergence angles; ② Influence of different convergence angles on the area and bonding strength of the post; ③ Retention force and frictional force of posts with different convergence angles; ④ The results of the one-way analysis of variance (ANOVA) of bonding strength, retention force and frictional force per unit area.RESULTS: ① The bonding strength of different convergence angles: It was 0.309 0 N/mm2 for the occlusal plane, 0.128 3 N/mm2 for the axial plane with a convergence angle of 0°, 0.108 7 N/mm2 for the 1.9°axial plane, 0.107 2 N/mm2 for the 3°axial plane, 0.084 9 N/mm2 for the 6°axial plane, 0.056 7 N/mm2 for the 9°axial plane, 0.046 3 N/mm2 for the 12°axial plane, 0.027 4 N/mm2 for the 15°axial plane. ② Bonding strength and bonding area of posts with different convergence angles: The post with a 0°convergence angle had a total post area of 108.047 mm2 and bonding strength of 19.041 N; The most tapered post with 14.71°had a total post area of 90.245 mm2 and bonding strength of 5.131 N. ③ The retention force of cast post and the bonding strength of ZPC declined with the increasing of convergence angles of the post. For the parallel post (convergence angle=0°), the retention force was 321.60 N, the frictional force was 302.559 N, retention force per unit area was 2.976 N/mm2,frictional strength was 3.885 N/mm2; for the most tapered post (convergence angle=14.71°), the retention force was 9.93 N, frictional force was 54.799 N, retention force per unit area was 0.664 N/mm2, frictional force was 0.681 N/mm2. ④ A one-way ANOVA showed that there were significant differences in the bonding strength, retention force and frictional force per unit area among the groups (P ＜ 0.05).CONCLUSION: The retention force, frictional force and the bonding strength of ZPC decrease with the increasing of convergence angles of posts, so the convergence angles of posts should be reduced as much as possible to obtain greater retention.

In vivo 1H magnetic resonance spectroscopy in evaluation of hepatocellular carcinoma and its early response to transcatheter arterial chemoembolization / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the value of in vivo proton magnetic resonance spectroscopy (MRS) in the assessment of hepatocellular carcinoma (HCC) and monitor its metabolic change shortly after transcatheter arterial chemoembolization (TACE).</p><p><b>METHODS</b>In this prospective study, 28 consecutive patients with large HCC (> or = 3 cm in diameter) confirmed by fine needle aspiration biopsy were recruited. The 1H MRS of all hepatic lesions and some uninvolved liver parenchyma were performed with 1. 5T whole body MR scanner. Among them, 15 cases were evaluated again about one week after TACE. The main metabolites such as choline and lipid before and after interventional therapy were measured to assess the early response of the tumor.</p><p><b>RESULTS</b>The technical success rate of 1H MRS in liver was high (33/41, 80%), closely related to breath motion, location of lesion, and size of voxel. In spectra, the choline compound peak of HCC elevated compared with uninvolved liver parenchyma. After TACE, both the amplitude and the area of choline resonance peak significantly descended (choline-to-lipid ratios from 0.352 +/- 0.080 to 0.167 +/- 0.030, P = 0.026; from 0.205 +/- 0.060 to 0.070 +/-0.020, P = 0.042, respectively); yet lipid resonance peak ascended.</p><p><b>CONCLUSIONS</b>In vivo 1H MRS is technically feasible for the evaluation of large focal hepatic lesions, however, the reproducibility and stability are not as good as routine MR scan. 1H MRS can monitor the early stage metabolic changes of HCC after TACE but limitation like quantification still exists.</p>