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OBJECTIVE@#To provide useful information for selecting the most appropriate peripheral nerve injury model for different research purposes in nerve injury and repair studies, and to compare nerve regeneration capacity and characteristics between them.@*METHODS@#Sixty adult SD rats were randomly divided into two groups and underwent crush injury alone (group A, n = 30) or transection injury followed by surgical repair (group B, n = 30) of the right hind paw. Each group was subjected to the CatWalk test, gastrocnemius muscle evaluation, pain threshold measurement, electrophysiological examination, retrograde neuronal labeling, and quantification of nerve regeneration before and 7, 14, 21, and 28 days after injury.@*RESULTS@#Gait analysis showed that the recovery speed in group A was significantly faster than that in group B at 14 days. At 21 days, the compound muscle action potential of the gastrocnemius muscle in group A was significantly higher than that in group B, and the number of labeled motor neurons in group B was lower than that in group A. The number of new myelin sheaths and the g-ratio were higher in group A than in group B. There was a 7-day time difference in the regeneration rate between the two injury groups.@*CONCLUSION@#The regeneration of nerve fibers was rapid after crush nerve injury, whereas the transection injury was relatively slow, which provides some ideas for the selection of clinical research models.
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Animals , Rats , Nerve Fibers , Nerve Regeneration , Rats, Sprague-Dawley , Sciatic Nerve/injuriesABSTRACT
The present study focused on the potential mechanism of betulin (BT), a pentacyclic triterpenoid isolated from the bark of white birch (Betula pubescens), against chronic alcohol-induced lipid accumulation and metaflammation. AML-12 and RAW 264.7 cells were administered ethanol (EtOH), lipopolysaccharide (LPS) or BT. Male C57BL/6 mice were fed Lieber-DeCarli liquid diets containing 5% EtOH for 4 weeks, followed by single EtOH gavage on the last day and simultaneous treatment with BT (20 or 50 mg/ kg) by oral gavage once per day. In vitro, MTT showed that 0-25 mM EtOH and 0-25 μM BT had no toxic effect on AML-12 cells. BT could regulate sterolregulatory-element-binding protein 1 (SREBP1), lipin1/2, P2X7 receptor (P2X7r) and NOD-like receptor family, pyrin domains-containing protein 3 (NLRP3) expressions again EtOH-stimulation. Oil Red O staining also indicated that BT significantly reduced lipid accumulation in EtOH-stimulated AML-12 cells. Lipin1/2 deficiency indicated that BT might mediate lipin1/2 to regulate SREBP1 and P2X7r expression and further alleviate lipid accumulation and inflammation. In vivo, BT significantly alleviated histopathological changes, reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and triglyceride (TG) levels, and regulated lipin1/2, SREBP1, peroxisome proliferator activated receptor α/γ (PPARα/γ) and PGC-1α expression compared with the EtOH group. BT reduced the secretion of inflammatory factors and blocked the P2X7rNLRP3 signaling pathway. Collectively, BT attenuated lipid accumulation and metaflammation by regulating the lipin1/2-mediated P2X7r signaling pathway.
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In current study, we aimed to investigate whether the gentiopicroside (GPS) derived from Gentiana manshurica Kitagawa could block the progression of alcoholic hepatic steatosis to fibrosis induced by chronic ethanol intake. C57BL/6 mice were fed an ethanol- containing Lieber-DeCarli diet for 4 weeks. LX-2 human hepatic stellate cells were treated with GPS 1 h prior to transforming growth factor-β (TGF-β) stimulation, and murine hepatocyte AML12 cells were pretreated by GPS 1 h prior to ethanol treatment. GPS inhibited the expression of type I collagen (collagen I), α-smooth muscle actin (α-SMA) and tissue inhibitor of metal protease 1 in ethanol-fed mouse livers with mild fibrosis. In addition, the imbalanced lipid metabolism induced by chronic ethanol-feeding was ameliorated by GPS pretreatment, characterized by the modulation of lipid accumulation. Consistently, GPS inhibited the expression of collagen I and α-SMA in LX-2 cells stimulated by TGF-β. Inhibition of lipid synthesis and promotion of oxidation by GPS were also confirmed in ethanol-treated AML12 cells. GPS could prevent hepatic steatosis advancing to the inception of a mild fibrosis caused by chronic alcohol exposure, suggesting GPS might be a promising therapy for targeting the early stage of alcoholic liver disease.
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OBJECTIVE Dihydroquercetin(TAX)is the most abundant dihydroflavone found in on-ions,milk thistle and Douglas fir bark.We investigated whether TAX could inhibit the lipid accumulation in alcoholic liver steatosis in vivo and in vitro.METHODS An in vivo model was established by intragas-trically treating mice with ethanol,and an in vitro model was created by treating HepG2 cells with etha-nol.RESULTS TAX regulated Sterol Regulatory Element-binding Protein-1(SREBP1)and Acetyl CoA Carboxylase (ACC) expression via elevating Liver Kinase B1 (LKB1)/ AMP-activated Kinase (AMPK) phosphorylation. Also, TAX upregulated SIRT1 expression, which suppressed by ethanal intake. Suppression of Purinergic 2X7 receptor (P2x7R), nucleotide-binding oligomerization domain-like re-ceptor protein 3(NLRP3)and Cysteine protease-1(caspase-1)cleavage by TAX resulted in the inhibi-tion of Interleukin-1β(IL-1β) production and release. Additionally, TAX reduced lipogenesis and pro-moted lipid oxidation via the regulation of AMPK and ACC in ethanol-treated steatotic HepG2 cell.TAX downregulated IL-1β cleavage response to Lipopolysaccharides (LPS) plus adenosine triphosphate(ATP) stimulation in HepG2 cells. P2x7R deficiency attenuated lipid accumulation with increasing AMPK activity and decreasing SREBP1 expression in ethanol-treated HepG2 cells.CONCLUSION Our data showed that TAX exhibited the inhibitory properties on lipogenesis and hepatoprotective ca-pacity,indicating that TAX has therapeutic potential for preventing alcoholic liver steatosis.
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OBJECTIVE To investigate toll-like receptor 4(TLR4)-related the regulation of Ornithog-alum caudatum extract(OCE)on inflammatory responses in lipopolysaccharide(LPS)activated macro-phages.METHODS Primary peritoneal macrophage,Raw 264.7,and THP-1 were incubated in 96-well plate for 24 h and treated with OCE of the concentration of 0-400 μg/ml for 4h.The viability of cells was measured by MTT assay.Specific concentrations of OCE were added into the medium of primary peri-toneal macrophage, Raw 264.7, and THP-1, respectively, then following with lipopolysaccharides (LPS). Cells were harvested and the total cellular protein and nuclear protein were extracted, and the protein content was determined using BCA protein assay Kit.The expressions of TLR4,inducible nitric oxide synthase(iNOS),cyclooxygenase 2(COX-2),α-inhibitor of NF-κB(IκB-α)and nuclear factor-κB (NF-κB)were assayed by Western blot.The expressions of interleukin-1α(IL-1α),interleukin-1β(IL-1β), interleukin-18(IL-18),and tumor necrosis factor-α(TNF-α)were measured by RT-PCR.RESULTS The results of MTT showed that OCE has no cytotoxicity in Raw 264.7 cells between 1.56 μg/ml and 400 μg/ml. Compared with normal group,the expressions of TLR4,iNOS,COX-2,NF-κB and IL-1α,IL-1β,IL-18, TNF-α,the level of nitric oxide(NO)were significantly increased by LPS stimulation,while OCE pretreat-ment reduced these increase induced by LPS. However, OCE pretreatment reversed the reduction of IκB-α after LPS stimulation.CONCLUSION OCE might suppress TLR4 expression and block the inflamma-tion process of NF-κB and iNOS,further decrease the expression of COX-2 and inhibit the release of inflammatory factors.
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OBJECTIVE The current study was designed to investigate the anti-steatosis effect of Pleurotus citrinopileatus extract (PC) and the underlying mechanism in vivo and in vitro. METHODS Acute and chronic alcoholic hepatosteatosis murine models and ethanol-treated HepG2 cells were applied. RESULTS In vitro,the anti-steatosis effect of PC was further confirmed via Nile red staining in HepG2 cells treated with ethanol.Both of acute and chronic alcohol-induced mice hepatosteatosis model,PC decreased serum aminotransferase and triglyceride accumulation. Upregulated sterol-regulatory element binding protein1(Srebp1),purinergic ligand-gated ion channel 7receptor(P2X7R)and downregulated sirtuin1 (SIRT1), adenosine 5′-monophosphate (AMP)-activated protein kinase α (AMPKα) caused by acute and chronic alcohol intake were modulated by PC.In ethanol-exposed HepG2 cells,PC reduced lipid accumulation in a concentration-dependent manner and exhibited superior ability in controlling lipid accumulation compared with metformin. CONCLUSION PC could abolish hepatic lipid accumulation through regulating SIRT1-AMPKα signaling in acute and chronic alcohol-induced hepatic steatosis.
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OBJECTIVE Regulating P2x7R- NLRP3 inflammasome activation might be a potentialtherapeutic strategy to treat alcoholic hepatosteatosis. We investigated whether this process would be modulated by gentiopicroside (GPS), which is attributed to the bitterness of gentian root extract. METHODSAn in vivo model was established by intragastrically treating mice with ethanol, and an in vitro modelwas created by treating HepG2 cells with ethanol or treating RAW 264.7 macrophages and murinebone marrow- derived macrophages (BMDMs) with lipopolysaccharides (LPS) plus adenosine triphos-phate (ATP). RESULTS In alcoholic hepatosteatotic mice model, GPS decreased serum aminotrans-ferase and triglyceride accumulation. GPS regulated sterol regulatory element-binding protein-1 (Srebp1),peroxisome proliferators- actived receptors α (PPARα) and acetyl CoA carboxylase (ACC) expressionvia elevating liver kinase B1 (LKB1)/AMP-activated Kinase (AMPK). Suppression of nucleotide-bindingoligomerization domain-like receptor protein 3 (NLRP3), caspase-1 and expression by GPS resulted inthe inhibition of interleukin-1β (IL-1β) production. In ethanol-exposed HepG2 cells, GPS reduced lipo-genesis and promoted lipid oxidation via P2x7R- NLRP3 inflammasome activation. P2x7R silencingenhanced AMPK activity, and reduced Srebp1 expression in ethanol-treated hepatocytes. GPS down-regulated P2x7R-mediated inflammatory response to extracellular ATP in LPS-primed RAW 264.7 macro-phages and BMDMs. Additionally, P2x7R deficiency attenuated IL- 1β cleavage in RAW 264.7 macro-phages, and GPS further suppressed IL-1β cleavage. CONCLUSION Activation of LKB1/AMPK signalingby GPS might be mediated by P2x7R-NLRP3 inflammasome, suggesting a therapeutic utility of P2x7Rblockade in alcoholic hepatosteatosis treatment.
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Objective Compare the HPV infection characters between women in different geographic area of Ankang (south of Shaanxi) and Yanan (north of Shaanxi),to provide evidence based reference for cervical cancer control.Methods PCR amplification in vitro combined reverse dot-blot hybridization assay were used to analyze HPV genotypes of 7 912 cases from Ankang City Center Hospital,and 3 543 cases from Yanan Affiliated Hospital of Yanan Medical University from June 2012 to July 2016,and compared HPV infection rate,age and hypotype distribution of the cases.Results The HPV infection rate of Ankang area was 21.75％ (1 721/7 912),and Yanan area was 41.41％ (1 402/1 721).The percentage of HPV positive women with high-risk hypotype was 81.46％ (1 402 1 721) in Ankang and 86.16％ (1 264/1 467) in Yanan,with low-risk hypotype was 11.04％ (190/1 721) in Ankang and 7.23％ (106/1 467) in Yanan,with high and low risk hypotype was 7.50％ (129 147) in Ankang and 6.61％ (97/1 467) in Yanan.The women more than 60 year old were higher HPV prevalence age group.The HPV infection rate of this age group was 30.41％ (104/342) in Ankang,and 50.00 ％ (60/120) in Yanan.Yanan's HPV infection rate was obviously higher than Ankang.The popular HPV hypotypes in Yanan were same with that in Ankang.The most popular high-risk hypotypes were HPV16,58 and 52,the most popular low-risk hypotypes were 6,11 and 81.Conclusion The HPV infection rate were rather high in all age group.The most popular HPV hypotypes were same between Ankang and Yanan area.But Yanan's HPV infection rate was obviously higher than Ankang (P＜ 0.01).The causes need further explore.
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Objective To provide reference for cervical cancer control by compare the HPV infection rate and distribution Xianyang and Baoji area.Methods Analysed HPV subtypes results of 1 356 cases in Baoji area and 7 708 cases in Xianyang area,and compared the age distribution,subtypes and positive rate of HPV infection in the women of the two areas.Results The HPV positive rate was 35.91% in Baoji area,and 32.14% in Xianyang area respectively.The most popular single subtype was HPV16,58,52 in the two areas.The dual-infection was most popular was HPV multiple infection in the two ar-eas.The HPV81 and HPV73 were not detected out in Baoji area,and all 23 HPV subtypes were detected out in Xianyang ar-ea.Conclusion The HPV infection rate in Baoji was higher than Xianyang(P<0.01).The high-risk HPV subtypes were same in the two areas.The HPV positive rate was high in all age groups.
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<p><b>OBJECTIVE</b>To explore the effects of resuscitation with different kinds of colloids on oxygen metabolism of swine during shock stage of burn injury.</p><p><b>METHODS</b>Eighteen Guangxi Bama miniature swine were inflicted with 40% TBSA full-thickness burn on the back. And then they were divided into succinylated gelatin group (S) , hydroxyethyl starch group (H), and allogeneic plasma group (A) according to the random number table, with 6 swine in each group. The fluid resuscitation was begun at post injury hour (PIH) 2. The colloids used in groups S, H, and A were respectively succinylated gelatin, 60 g/L hydroxyethyl starch 130/0.4, and allogeneic plasma. The blood pressure, urine volume, heart rate, and central venous pressure (CVP) were recorded before injury and at the first and second PIH 24. The volume of resuscitation fluid was recorded at the first and second PIH 24. The changes in oxygen delivery., oxygen consumption, oxygen extraction ratio and D-lactate were determined and calculated before injury and at PIH 4, 8, 24, and 48. Data were processed with analysis of variance of repeated measurement, one-way analysis of variance and LSD test.</p><p><b>RESULTS</b>There were no statistically significant differences among the three groups in blood pressure, urine volume, heart rate, and CVP at each time point (with P values above 0. 05). There were no statistically significant differences in resuscitation fluid volume among the three groups at the first and second PIH 24 (with F values respectively 0. 239 and 2. 023, P values respectively 0. 790 and 0. 167). The oxygen consumption of swine in group S was (201 ± 38) L · min(-1) · m(-2) at PIH 48, which was significantly higher than that in group A [(150 ± 37) L · min(-1) · m(-2), P < 0.05], and the oxygen consumption was similar among the three groups at the rest time points (with P values above 0.05). The oxygen delivery of swine in group S was (484 ± 63) L · min(-1) · m(-2) at PIH 8, and it was significantly lower than that in group A [(652 ± 65) L(-1) min(-1) · m(-2), P < 0.01]. The oxygen delivery of swine in group S reached (903 ± 132) and (1,028 ± 98) L · min(-1) · m(-2) at PIH 24 and 48, respectively, and they were significantly higher than those in group A [(686 ± 72) and (720 ± 75) L · min(-1) · M(-2), with P values below 0.01]. Oxygen delivery in group H was similar to that of group A at each time point (with P values above 0.05). The oxygen extraction ratio in group S or group H was close to that of group A at each time point (with P values above 0.05). The D-lactate level in group S was (69 ± 9) mmol/L, and it was significantly higher than that in group A [(52 ± 4) mmol/L, P < 0.01] at PIH 48. The D-lactate level was similar among the three groups at the rest time points (with P values above 0.05).</p><p><b>CONCLUSIONS</b>According to the changes in oxygen metabolism of swine during shock stage of burn injury resuscitated with different kinds of colloids, it is found that allogeneic plasma is better than artificial colloid, and 60 g/L hydroxyethyl starch 130/0.4 is superior to succinylated gelatin.</p>
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Animals , Blood Pressure , Burns , China , Colloids , Pharmacology , Fluid Therapy , Hydroxyethyl Starch Derivatives , Oxygen , Metabolism , Resuscitation , Methods , Shock , SwineABSTRACT
<p><b>OBJECTIVE</b>To investigate human papilloma virus (HPV) infection and typing in 7 640 cases of women in Shanxi province in order to provide theoretical basis for the prevention and treatment of the cervical cancer.</p><p><b>METHODS</b>Totally, 7 640 cases of cervical cell specimens in Shanxi provincial tumor hospital, screening and physical examination from 2012 January to 2013 May and 23 HPV genotypes were analyzed by PCR and reverse dot blot gene chip technology.</p><p><b>RESULTS</b>A total of 1 441 cases of patients with HPV infection were to be found in 7 640 cases of women with an average age of (42.26 ± 19.15)years old. The total infection positive rate, infection rate of high-risk HPV, infection rate of low-risk HPV and infection rate of mixed high and low risk were 18.86% (1 441/7 640), 16.03% (1 225/7 640, including multiple high-risk of HPV infection), 4.88% (373/7 640, including multiple low-risk of HPV infection) and 2.05% (157/7 640) respectively. The rate of high-risk HPV infection was 85.01% (1 225/1 441) in total infection positive women. The most common subtype was HPV16 (34.70%, 523/1 507) and followed by HPV58 (11.48%, 173/1 507), HPV18 (7.43%, 112/1 507), HPV33 (7.10%, 107/1 507), HPV56 (6.04%, 91/1 507) and HPV52 (5.51%, 83/1 507) respectively in tested 18 high-risk HPV subtypes, and there was no HPV82. The most common subtype was HPV43 (38.13%, 151/396) and followed by HPV42 (22.22%, 88/396), HPV81 (20.45%, 81/396), HPV6 (11.87%, 47/396) and HPV11 (7.32%, 29/396) respectively in tested 5 low-risk HPV subtypes. The HPV infection positive rates were significantly different in different age groups and HPV total infection rate, high-risk infection rate in 41-50 year-old age group was the highest, 23.23%. The infection rates of single subtype of HPV and single high-risk subtype of HPV were 75.71% (1 091/1 441) and 61.35% (884/1 441) respectively in all cases of infection women and single high-risk subtype infection rate was 81.03% (884/1 091) in all cases of single subtype infection women. The infection rate of multiple subtype of HPV was 24.29% (350/1 441) in all cases with HPV infection. The double infections was most common (18.18%, 262/1 441) in which the women of double high-risk infections of HPV were 151 cases (10.48%, 151/1 441). The rates of double infection, triple infection and quadruple or more infection of HPV were 74.86% (262/350), 20.29% (71/350) and 4.89% (17/350) respectively in all cases with HPV multiple infection. The positive rates of HPV infection in different age groups were obvious difference. The positive rate of single infection of HPV was 17.80% (574/3 224) in cases of 41-50 years old group which higher than that in other groups(χ² = 20.18, P < 0.05).</p><p><b>CONCLUSION</b>The more common high-risk HPV subtype is HPV16, HPV58, HPV18, HPV33, HPV56 and HPV52 and low-risk HPV subtype is HPV43, HPV42 in Shanxi province. HPV infection is most common in the age group of 41- 50 years old female.</p>
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Adult , Aged , Female , Humans , Middle Aged , Young Adult , Uterine Cervical Dysplasia , Epidemiology , Virology , China , Epidemiology , Cross-Sectional Studies , DNA, Viral , Genetics , Genotype , Human papillomavirus 16 , Genetics , Oligonucleotide Array Sequence Analysis , Papillomaviridae , Classification , Genetics , Papillomavirus Infections , Epidemiology , Virology , Risk Factors , Uterine Cervical Neoplasms , Epidemiology , VirologyABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of lamivudine, interferon alpha and oxymatrine treatment for surviving hepatic failure patients with hepatitis B.</p><p><b>METHODS</b>200 hepatitis B patients, including 100 subacute or acute-on-chronic hepatic failure survivals (group A), and 100 chronic (group B, n=100) hepatic failure survivals, were enrolled in this study. Patients in group A received interferon alpha (n=35), lamivudine (n=33) , or combinational lamivudine and oxymatrine (n=32) therapy for six months; Patients in group B received lamivudine (n=49), or combinational lamivudine and oxymatrine (n=51) therapy for six months, respectively. After the treatment, all patients were followed-up for six months.</p><p><b>RESULTS</b>At the end of follow-up, all patients in group A survived, while in group B three patients (6.1%) receiving lamivudine, and four (7.8%, P>0.05) receiving combinational therapy died; more than 90% of all survivals had their HBV DNA loss. The HBeAg/anti-HBe seroconversion rate in patients of group A treated with interferon alpha (9/17, 52.9%) was higher than that in patients treated with combinational lamivudine and matrine (5/16, 31.3%, P<0.05), which was higher than that in the patients treated with lamivudine alone (1/17, 5.9%, P<0.01), and the Knodell histological activity index score in patients treated with lamivudine (7.2+/-0.8, P<0.05) was lower than that in patients treated with interferon alpha (8.2+/-1.3, P<0.05), and the best efficacy was found in receiving combinational therapy (6.9+/-0.7, P<0.01); Lamivudine or lamivudine in combination with matrine significantly inhibited the intrahepatic inflammatory activities, but had no effect on the existing fibrosis in group B patients.</p><p><b>CONCLUSION</b>Long term nucleotide analogues treatment may delay the progress of fibrosis in hepatitis B-induced hepatic failure survivals, and the administration of matrine in time may further enhance the anti-fibrotic effect of nucleotide analogues.</p>
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Adolescent , Adult , Female , Humans , Male , Middle Aged , Young Adult , Alkaloids , Therapeutic Uses , Antiviral Agents , Therapeutic Uses , DNA, Viral , Blood , Drug Therapy, Combination , Follow-Up Studies , Hepatitis B , Drug Therapy , Pathology , Hepatitis B e Antigens , Blood , Hepatitis B virus , Interferon-alpha , Therapeutic Uses , Lamivudine , Therapeutic Uses , Liver Failure , Blood , Drug Therapy , Pathology , Liver Function Tests , Quinolizines , Therapeutic Uses , Treatment OutcomeABSTRACT
<p><b>OBJECTIVE</b>To evaluate the effect of autologous bone marrow-derived stem cell (BMSCs) transplantation in the treatment of liver failure and decompensated hepatic cirrhosis.</p><p><b>METHODS</b>Bone marrow was harvested (65-95 ml) from 24 patients in the transplantation group. The BMSCs were isolated and infused into liver or spleen of patients via hepatic or splenic artery. At different time points after the transplantation, the patients' liver function and prothrombin time (PT) were evaluated, and the survival rate and symptoms of the patients were recorded.</p><p><b>RESULTS</b>All the serum biochemical indexes remained stable 2 weeks after the transplantation, and at 4 weeks after transplantation, albumin level increased significantly in comparison with the preoperative level (P<0.05). At 12 weeks, the albumin level further increased (P<0.01) along with Pre-ALB (P<0.01), while total bilirubin, tolal bile acid, PT and fibrinogen were all significantly lowered (P<0.05), and globulin, ALT, and AST remained unchanged (P>0.05). One week after the transplantation, improved appetite was observed in 22 cases (91.67%), and 21 cases (87.5%) showed better physical strength; at 2 weeks, hepatic face improved in 15 cases (62.5%), and spider telangiectasia was significantly reduced in one case; at 12 weeks, the survival rate of the patients was 62.5%, and 9 died or gave up treatment due to chronic liver failure complicated by spontaneous bacterial peritonitis, hepatorenal syndrome, or DIC. No complications associated with the transplantation occurred in these patients.</p><p><b>CONCLUSION</b>BMSC transplantation can significantly improve the liver function of patients with terminal liver disease with good safety and effectiveness.</p>
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Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Bone Marrow Transplantation , Methods , Liver Cirrhosis , General Surgery , Liver Failure , General Surgery , Liver Function Tests , Stem Cell Transplantation , Methods , Transplantation, Autologous , Treatment OutcomeABSTRACT
<p><b>OBJECTIVE</b>To explore mechanical properties of the composite archwire (CoAW) applied in extraction cases.</p><p><b>METHODS</b>The mandibular three dimensional model was established by spiral computed tomography scanning and SOLIDWORKS 2001 PLUS software. The archwire model was established by means of ANSYS software. The mechanical analysis and calculation of CoAW were carried out.</p><p><b>RESULTS</b>With the diameter of NiTi part of CoAW gradually augmented (the diameter of stainless steel part kept unchanged), the stress on teeth gradually increased. As the diameter of stainless steel part of CoAW gradually augmented (the diameter of NiTi part kept unchanged), the stress on teeth also gradually increased. The CoAW (0.30 mm NiTi round wire combined with 0.36 mm stainless steel round wire) produced the least force on teeth. There was little contradistinction between six kinds of CoAW and stainless steel wire on the stress of posterior teeth.</p><p><b>CONCLUSIONS</b>The stress on teeth closely correlated with the diameter of the composite archwire.</p>
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Humans , Dental Stress Analysis , Finite Element Analysis , Orthodontic Wires , Orthodontics, Corrective , Tooth ExtractionABSTRACT
<p><b>AIM</b>To design and synthesize some cephalotaxine and drupacine derivatives with different substituentes on C3'-N of taxol side chain.</p><p><b>METHODS</b>Protective side chain acid VI (4'S,5'R) was prepared from optically active (2'R,3'S) methyl beta-phenyl glycidate I in five steps. The desired acids were coupled with cephlotaxine and drupacine respectively in the presence of 2-DPC/DMAP, followed by acidic hydrolysis and acylating to give novel alkloid esters with different substitutes on C3'-N.</p><p><b>RESULTS</b>The seven new esters were studied for antitumor activity, the results showed that the antitumor activity was influenced by the substituentes on C3'-N.</p><p><b>CONCLUSION</b>It might provide some rational basis for further structral modification.</p>