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The rising prevalence of nonalcoholic fatty liver disease (NAFLD) is now the second largest indication for liver transplantation in Western countries, but viral hepatitis B and end-stage alcohol-related liver disease are still the main indications in China. With the improvement of people's living standards, the prevalence of metabolic syndrome, and the number of NAFLD patients has also gradually increased. At the same time, with the hepatitis B vaccination popularization and the nucleos(t)ide analogues and other drugs uses, it is predicted that NAFLD-related end-stage liver disease may become one of the main indications for liver transplantation in our country in the future. This article reviews the research progress of NAFLD and liver transplantation.
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Humanos , Doença Hepática Terminal , Transplante de Fígado/efeitos adversos , Síndrome Metabólica , Hepatopatia Gordurosa não Alcoólica/epidemiologia , PrevalênciaRESUMO
Purpose@#The aim of this study was to compare the efficacy of liver transplantation (LT) and liver resection (LR) for hepatocellular carcinoma (HCC) patients with portal vein tumor thrombus (PVTT) and to investigate risk factors affecting prognosis. @*Materials and Methods@#A total of 94 HCC patients with PVTT type I (segmental PVTT) and PVTT type II (lobar PVTT) were involved and divided into LR (n=47) and LT groups (n=47). Recurrence-free survival (RFS) and overall survival (OS) were compared before and after inverse probability of treatment weighting (IPTW). Prognostic factors for RFS and OS were explored. @*Results@#Two treatment groups were well-balanced using IPTW. In the entire cohort, LT provided a better prognosis than LR. Among patients with PVTT type I, RFS was better with LT (p=0.039); OS was not different significantly between LT and LR (p=0.093). In subgroup analysis of PVTT type I patients with α-fetoprotein (AFP) levels >200 ng/mL, LT elicited significantly longer median RFS (18.0 months vs. 2.1 months, p=0.022) and relatively longer median OS time (23.6 months vs. 9.8 months, p=0.065). Among patients with PVTT type II, no significant differences in RFS and OS were found between LT and LR (p=0.115 and 0.335, respectively). Multivariate analyses showed treatment allocation (LR), tumor size (>5 cm), AFP and aspartate aminotransferase (AST) levels to be risk factors of RFS and treatment allocation (LR), AFP and AST as risk factors for OS. @*Conclusion@#LT appeared to afford a better prognosis for HCC with PVTT type I than LR, especially in patients with AFP levels >200 ng/mL.
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OBJECTIVES@#To evaluate the effects of antimicrobial peptide GH12 designed @*METHODS@#The cariogenic three-species biofilm consis-ted of the cariogenic @*RESULTS@#The biomass and density of the cariogenic three-species biofilm treated with GH12 decreased compared with those of the control. The number of @*CONCLUSIONS@#GH12 can reduce the number of
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Humanos , Biofilmes , Cárie Dentária , Hibridização in Situ Fluorescente , Proteínas Citotóxicas Formadoras de Poros , Streptococcus mutansRESUMO
Objective To design a device for studying the effects of shear stress on the activity of blue-green algae.Methods The device was optimized in terms of the weakness of current shear stress devices,such as small volume,unstability,inability for quantitative analysis and short working period.The effective volume of the new device was 400-700 mL,and the error was less than 13.8％.Moreover,this device could produce a quantitative and uniform shear stress field and be continued to follow observation for more than 96 hours.Results By experiment on growth of microcystis aeruginosa,the device was proved to generate shear stress that could significantly affect the activity of microcystis aeruginosa cells.Conclusions This experimental device is an effective equipment for investigating the effects of shear stress on the activity of blue-green algae.
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Objective To design a device for studying the effects of shear stress on the activity of blue-green algae.Methods The device was optimized in terms of the weakness of current shear stress devices,such as small volume,unstability,inability for quantitative analysis and short working period.The effective volume of the new device was 400-700 mL,and the error was less than 13.8％.Moreover,this device could produce a quantitative and uniform shear stress field and be continued to follow observation for more than 96 hours.Results By experiment on growth of microcystis aeruginosa,the device was proved to generate shear stress that could significantly affect the activity of microcystis aeruginosa cells.Conclusions This experimental device is an effective equipment for investigating the effects of shear stress on the activity of blue-green algae.
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Objective To design a device for studying the effects of shear stress on the activity of blue-green algae. Methods The device was optimized in terms of the weakness of current shear stress devices, such as small volume, unstability, inability for quantitative analysis and short working period. The effective volume of the new device was 400-700 mL, and the error was less than 13.8%. Moreover, this device could produce a quantitative and uniform shear stress field and be continued to follow observation for more than 96 hours. Results By experiment on growth of microcystis aeruginosa, the device was proved to generate shear stress that could significantly affect the activity of microcystis aeruginosa cells. Conclusions This experimental device is an effective equipment for investigating the effects of shear stress on the activity of blue-green algae.
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Objective To demonstrate the relationship between modified Hausdorff distance (MH) and the spatial change of arterial vasculature in residuum. Methods Data of the vascular model were obtained from CT scans of clinical cases, and a centerline model of the residuum vasculature was established by setting the appropriate parameter of distance between control points (DCP) in MIMICS 10.0. Deformation was applied on the model through compiling the program in MATLAB. The MH values before and after the deformation were calculated and analyzed. According to different locations of the rotation axis, the deformation was divided into four cases (C1, C2, C3, C4) on the basis of growth order in node numbers and total length of the vasculature. Results MH increased with the increment of the vascular rotation angle, but due to different maximum rotation radius and total length of the vascular vessel, 4 deformed models showed different growth trends. With the rotation angle increasing, MH gradually increased from C1 to C4. The maximum change occurred from C2 to C3, and minimal change occurred from C3 to C4. Specifically, the maximum rotation radius and total length of the vessels from C1 to C2 increased by 22.2% and 91.3%, while those from C3 to C4 increased by 14.1% and 26.8%, respectively. Moreover, the maximum change of MH value was 60.4% from C1 to C2 and 4.5% from C3 to C4. Conclusions MH can be an effective parameter to indicate spatial change of the residuum vasculature. MH of the residuum vasculature is proportional to deformation angle of the vessel, and the maximum rotation angle has a significant influence on MH. Moreover, when DCP is smaller than 3 mm, the influence of parameter setting can be avoided effectively. In addition, MH can also be applied in the studies of vasculature change and comparison.
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Objective To investigate stress and bone density distribution changes in the mandible due to the interference fit in titanium dental implants for mandible reconstruction, and study the influence of interference magnitudes on mandibular bone remodeling. Methods Eight interference fit models with titanium implants were established by finite element method. Bone remodeling based on strain energy density (SED) algorithm was employed to investigate changes in stress and bone density of the mandible in the models during 36 months with inference magnitude of 5%, 10%, 15%, 20%, 25%, 30%, 35% and 40%, respectively. Results When the diameter of pilot hole was larger than the internal diameter of titanium screw, the increment of interference magnitude would gradually enhance the screw fixation at the bone titanium dental implant interface. However, once the magnitude of interference exceeded 30%, the increase in interference magnitude might weaken the screw fixation due to the failure and loss of bone. Conclusions The diameter of pilot hole equal to or slightly smaller than the internal diameter of titanium screw is recommended for mandibular reconstruction.
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Objective To provide an optimization method and a basic configuration for the configuration design of mandibular defect-repair implant. Methods A topology optimization computation based on density method was adopted to make topology optimization on reconstruction titanium plate for repairing mandibular defect. Results The effects of volume fraction F and penalization factor p on the optimized configuration were compared and analyzed, respectively, and the optimum parameters were chosen to be F=0.65 and p=3.5. Using this set of parameters, optimized computation was performed on the mandibular defect-repair implant, and the three opening configuration was proved to be the basic optimization configuration. The result also showed that unilateral molar clenching had more significant effect on stress distributions in the implant as compared to incisal clenching. Conclusions A set of parameters suitable for optimizing configuration of mandibular defect-repair implant, as well as the basic configuration of optimized titanium plate were obtained, which could provide references for the design of mandibular defect-repair implant in clinic.
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Objective To investigate the influence of graft-host diameter ratio on the flow field of fully-occluded artery bypass grafts and provide a theoretical guidance for reducing restenosis in artery bypass graft surgery. Methods Five models were employed to numerically investigate the influence of graft-host diameter ratio on the flow field of fully-occluded artery bypass grafts. The distributions of hemodynamic parameters such as velocity, second flow, wall shear stress (WSS) and wall shear stress gradient (WSSG) and their change in line with the increase of diameter ratio were analyzed. In addition, comparison of hemodynamic differences in a fully-occluded complete model (Model A), a fully-occluded partial model (Model B) and a 75% stenosis complete model (Model C) with graft-host diameter ratio of 1.0 was conducted to validate the fully-occluded complete model established in this study. Results The hemodynamic performance of Model A was totally different from that of Model C, and the velocity distribution at the graft top had an obvious influence on the WSS distribution at host artery bed in the downstream anastomosis, with maximum WSS differences reaching 79%. A large graft-host diameter ratio resulted in a large size of low WSS region at the host artery bed, but with uniformly distributed WSS and small WSSG. A small graft-host diameter ratio resulted in a small size of low WSS region at the host artery bed, but with large WSSG. Conclusions It is necessary to adopt a complete model to study the influence of graft-host diameter ratio on the flow field of fully-occluded artery bypass grafts. The diameter ratio had a significant impact on the flow field of fully-occluded artery bypass graft, thus a large ratio could be helpful to reduce the occlusion resulted from the restenosis at the downstream anastomosis in artery bypass graft.
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Objective To investigate effects of pressure and tail suspension on the growth of rat skeletal muscles by establishing the tail-suspended rat model and pressure-induced rat model, respectively. Methods Thirty-six male Sprague-Dawley rats were randomly divided into three groups: the control-group (CON), the tail-suspended group (SUS), the pressure group (PRE), and each group was undergoing two stages (7, 14 d) for observation. At the end of the experiment, the muscle wet weight/body weight (Mww/Bw), muscle fiber cross-sectional area (MFCSA), muscle fiber diameter (MFD) of soleus and extensor digitorum longus (EDL) and the IGF-1 concentration were measured, respectively. Results For both the SUS group and PRE group with 7 d, their Mww/Bw, MFCSA and MFD of soleus were significantly reduced (P<0.05) as compared to the CON group, which were reduced by 23.52%, 14.26%, 13.47% in PRE group, respectively, while these indexes in SUS group were reduced by 23.52%, 33.07%, 25.09%, respectively. Meanwhile, the decrease of Mww/Bw, MFCSA and MFD in PRE group with 14 d was reduced by 20.51%, -10.49%, -5.73%, respectively, which was less than that in PRE group with 7 d. However, the decrease of Mww/Bw in SUS group with 14 d reached 46.15%, showing significantly higher than that of the SUS group with 7 d. For the IGF-1 concentration and EDL changes, no remarkable differences were found among the CON, PRE and SUS groups. Conclusions The impact of pressure on the process of soleus growth is different from that of the suspension (disuse). During the early stage of pressure application, the deep tissue injury mainly with inflammatory responses can be found in the muscle. When the muscle cells adapt to the pressure environment, they may produce a functional adaptation to growth. Therefore, such effect of socket pressure on skeletal muscle should be considered in clinic for prosthetic socket design or rehabilitation training, which will help protect the muscle tissues.
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Objective To investigate effects of pressure and tail suspension on the growth of rat skeletal muscles by establishing the tail-suspended rat model and pressure-induced rat model, respectively. Methods Thirty-six male Sprague-Dawley rats were randomly divided into three groups: the control-group (CON), the tail-suspended group (SUS), the pressure group (PRE), and each group was undergoing two stages (7, 14 d) for observation. At the end of the experiment, the muscle wet weight/body weight (Mww/Bw), muscle fiber cross-sectional area (MFCSA), muscle fiber diameter (MFD) of soleus and extensor digitorum longus (EDL) and the IGF-1 concentration were measured, respectively. Results For both the SUS group and PRE group with 7d, their Mww/Bw, MFCSA and MFD of soleus were significantly reduced (P<0.05) as compared to the CON group, which were reduced by 23.52%, 14.26%, 13.47% in PRE group, respectively , while these indexes in SUS group were reduced by 23.52%, 33.07%, 25.09%, respectively. Meanwhile, the decrease of Mww/Bw, MFCSA and MFD in PRE group with 14d was reduced by 20.51%, -10.49%, -5.73%, respectively, which was less than that in PRE group with 7d. However, the decrease of Mww/Bw in SUS group with 14d reached 46.15%, showing significantly higher than that of the SUS group with 7d. For the IGF-1 concentration and EDL changes, no remarkable differences were found among the CON, PRE and SUS groups. Conclusions The impact of pressure on the process of soleus growth is different from that of the suspension (disuse). During the early stage of pressure application, the deep tissue injury mainly with inflammatory responses can be found in the muscle. When the muscle cells adapt to the pressure environment, they may produce a functional adaptation to growth. Therefore, such effect of socket pressure on skeletal muscle should be considered in clinic for prosthetic socket design or rehabilitation training, which will help protect the muscle tissues.
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<p><b>BACKGROUND</b>Precise evaluation of the live donor's liver is the most important factor for the donor's safety and the recipient's prognosis in living donor liver transplantation (LDLT). Our study assessed the clinical value of computer-assisted three-dimensional quantitative assessment and a surgical planning tool for donor evaluation in LDLT.</p><p><b>METHODS</b>Computer-assisted three-dimensional (3D) quantitative assessment was used to prospectively provide quantitative assessment of the graft volume for 123 consecutive donors of LDLT and its accuracy and efficiency were compared with that of the standard manual-traced method. A case of reduced monosegmental LDLT was also assessed and a surgical planning tool displayed the precise surgical plan to avoid large-for-size syndrome.</p><p><b>RESULTS</b>There was no statistically significant difference between the detected graft volumes with computer-assisted 3D quantitative assessment and manual-traced approaches ((856.76 ± 162.18) cm(3) vs. (870.64 ± 172.54) cm(3), P = 0.796). Estimated volumes by either method had good correlation with the actual graft weight (r-manual-traced method: 0.921, r-3D quantitative assessment method: 0.896, both P < 0.001). However, the computer-assisted 3D quantitative assessment approach was significantly more efficient taking half the time of the manual-traced method ((16.91 ± 1.375) minutes vs. (39.27 ± 2.102) minutes, P < 0.01) to estimate graft volume. We performed the reduced monosegmental LDLT, a pediatric case, with the surgical planning tool (188 g graft in the operation, which was estimated at 208 cm(3) pre-operation). The recipient recovered without large-for-size syndrome.</p><p><b>CONCLUSIONS</b>Computer-assisted 3D quantitative assessment provided precise evaluation of the graft volume. It also assisted surgeons with a better understanding of the hepatic 3D anatomy and was useful for the individual surgical planning tool.</p>
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Humanos , Simulação por Computador , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Técnicas In Vitro , Fígado , Diagnóstico por Imagem , Cirurgia Geral , Transplante de Fígado , Doadores Vivos , Tamanho do Órgão , Tomografia Computadorizada por Raios XRESUMO
Objective To investigate effects from the protrusion height of drug-eluting stent (DES) on kinetics of drug release and hemodynamics, so as to provide references for the optimization of DES design. Methods Based on computational fluid dynamics (CFD), coupling analysis on kinetics of drug release and hemodynamics was conducted by studying three stent models with different protrusion height to numerically investigate the distribution of drug concentration and wall shear stress. Results The increase in protrusion height of the stent was beneficial to the drug deposition; however, it could also increase the length in the low shear stress area. Comparatively, the increase percentage of drug concentration with the increasing protrusion height was remarkably less than that of the increasing length in low shear stress area. Conclusions By comprehensive consideration of both the drug concentration and wall shear stress, lower protrusion height is recommended for DES so as to effectively reduce the risk of restenosis.
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Objective To establish the model of dentulous mandible and straight wire appliance and investigate the stress and displacement distributions of the roots and periodontal tissues under en masse space closure with sliding mechanics. Methods The three-dimensional finite element model of mandible and teeth was developed from CT images, which consisted of the dentin, enamel, dental pulp, PDL (periodontal ligament), cortical and cancellous bone. The models of Roth straight wire brackets with actual data were also constructed. The dental adhesives were used to stick the brackets on the corresponding teeth. Contact elements were used to simulate the interaction between the stainless steel arch wire and the brackets. Moreover, spring elements were used to connect the brackets and the arch wire. The load with the value of 1 N was applied on the model to close the space. Results The lingual tipping of lateral and central incisors was found, corresponding with the clinical observation of en masse space closure with sliding mechanics. High stress in the teeth and periodontal tissue appeared at the incisors and the distal roots of the first molars. The maximum von Mises stresses in PDL of the central incisors and the distal roots of the first molars were 3.97 kPa and 5.75 kPa, respectively. Conclusions In order to avoid root resorption of incisors, the torque of the brackets could be increased. Less orthodontic forces or orthodontic implant could be used to avoid distal roots of first molars.
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Objective To study the effect from drug diffusion coefficient of atherosclerotic plaque on drug diffusion within the arterial wall, so as to truly reflect the drug distributions. Methods Using computational fluid dynamics (CFD) method, five plaque models with different diffusion coefficients were employed to numerically investigate the distributions of drug concentration both within the arterial wall and the plaque. Results The drug concentration in the arterial wall was increased gradually with the diffusion coefficient of the plaque increased; however, the increment would become gentle. Conclusions When the diffusion coefficient in the plaque was smaller than the tissue, the plaque inhibited the drug diffusion within the arterial wall, or conversely, it would promote the diffusion. Especially when the diffusion coefficient in the plaque was much larger than the tissue, it no longer affected the drug diffusion within the arterial wall. It is necessary to consider the impact of plaque in further research, which is beneficial to the optimization design of drug-eluting stents.
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<p><b>OBJECTIVE</b>To analyze the prognosis of hepatitis B virus (HBV) recurrence after liver transplantation.</p><p><b>METHODS</b>Thirty-eight patients (37 males; 1 female) with HBV-related end-stage liver disease underwent liver transplantation at our institute between December 1998 and November 2009 and experienced HBV recurrence. Clinical data from pre-transplant and follow-up examinations were retrospectively retrieved from medical records, and included serologic indices of HBV (HBV DNA, markers of liver function) and histological findings from liver biopsy.</p><p><b>RESULTS</b>The median follow-up time was 45.1 months. The median time to HBV recurrence after transplantation was 31.8 months (range: 0.3 to 72.8 months) for histologically benign cases and 13.7 months (range: 0.3 to 66.6 months) for malignant cases. HBV DNA gene mutations were detected in 21% (8/38) of cases. Eighteen patients were treated with entecavir or adefovir, with respect to gene mutations, and HBV DNA fell below 103 copies/ml and liver function became normal. Twenty-two patients died, and causes of death included hepatocellular carcinoma (HCC, n=18), organ failure (n=2), or infection (n=1).</p><p><b>CONCLUSION</b>HBV gene mutations and HCC recurrence were important risk factors for HBV recurrence in our study population. In addition, patients with benign liver diseases who received salvage therapy with adefovir or entecavir achieved a satisfactory prognosis.</p>
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Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adenina , Farmacologia , Hepatite B , Diagnóstico , Virologia , Vírus da Hepatite B , Genética , Lamivudina , Farmacologia , Transplante de Fígado , Organofosfonatos , Farmacologia , Prognóstico , Recidiva , Estudos RetrospectivosRESUMO
Muscle atrophy of the stumps after lower limb amputation has always been a crucial factor resulted in inefficient clinical rehabilitation and athletic recovery for the amputated patients. Therefore, understanding the initiating and developing mechanism of muscle atrophy is very important for the improvement of amputation，restoration training and prosthetic design，which is also widely concerned in the prosthetic rehabilitation field. This paper will review the advances of residual limb muscle atrophy researches on the approaches and models，the mechanical properties of the residual limb，the micro pathologic characteristics as well as the prevention strategies of muscle atrophy in recent years. It can be concluded that further researches are needed to study the special physiologic and mechanical environment in residual limb, which affected the growth of muscle cells as well as the dynamic balance of the muscle protein synthesis and decomposition before completely understanding the mechanism of residual limb muscle atrophy and definitely clarifying its real cause.
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Objective To investigate the influence of the location of drug release and the stent spacing on drug deposition in curved artery walls. Method 2D curved artery and strut models were employed to carry out a numerical investigation on drug deposition under different drug release surfaces or stent spacing ( 1 strut length, 3 strut lengths, 7 strut lengths ). The results were compared with those in a straight artery. Results The drug depositions produced by four different surfaces of a single strut were quite different. Compared with the curved artery, the superiority of drug release from the top surface of the straight artery was reduced, while the weakness of drug release from proximal surface was substantially increased. There was no significant change for drug release from the distal surface. The average drug concentration increased with interstrut spacing increasing, but the percentage increase was less than that in the straight artery. Concentration differences were observed between the inside and outside of the curved artery, which on the outside showed much lower. Conclusions The local flow alteration, the drug release location and the stent spacing have significant effects on drug deposition in a curved artery and the result is obviously different from that in a straight artery.
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<p><b>OBJECTIVE</b>To investigate the donor evaluation, surgical protocol, and the complication for the adult-to-adult living donor liver transplantation (AALDLT).</p><p><b>METHODS</b>There were 94 cases of AALDLT were performed by the same surgical team from January 2007 to August 2010. Patients aged from 18 to 74 years. Donors aged from 19 to 60 years. All the 94 cases' operation protocol as following, 2 cases with left lobe liver graft, 92 cases with right lobe graft, 44 cases with middle hepatic vein (MHV) harvested, and 48 cases without MHV. Assessment methods of donors, postoperative complications and the current survival were analyzed.</p><p><b>RESULTS</b>All the donors were discharged with good recovery, complication incidence of donor was 7.4%. Median time of follow-up was 37 months. Eight patients were died during follow-up, 1-year patient survival rate was 95.7%, and graft survival rate was 94.4%. One case complicated with small-for-size syndrome, 1 case was performed re-transplantation for acute hepatic necrosis, 24 patients (25.5%) showed biliary anastomotic stenosis defined cholangiography or magnetic resonance cholangiopancreatography examination, and 9 patients (9.6%) showed abnormal liver function.</p><p><b>CONCLUSIONS</b>Living donor liver transplantation is an effective treatment method for end-stage liver disease, with accurate evaluation preoperative, a reasonable surgical approach, whether using the left or right lobe liver graft, with or without middle hepatic vein in AALDLT can effectively ensure the donor and recipient safety.</p>