In this paper, we propose a new active contour algorithm, i. e. hierarchical contextual active contour (HCAC), and apply it to automatic liver segmentation from three-dimensional CT (3D-CT) images. HCAC is a learning-based method and can be divided into two stages. At the first stage, i.e. the training stage, given a set of abdominal 3D-CT training images and the corresponding manual liver labels, we tried to establish a mapping between automatic segmentations (in each round) and manual reference segmentations via context features, and obtained a series of self-correcting classifiers. At the second stage, i.e. the segmentation stage, we firstly used the basic active contour to segment the image and subsequently used the contextual active contour (CAC) iteratively, which combines the image information and the current shape model, to improve the segmentation result. The current shape model is produced by the corresponding self-correcting classifier (the input is the previous automatic segmentation result). The proposed method was evaluated on the datasets of MICCAI 2007 liver segmentation challenge. The experimental results showed that we would get more and more accurate segmentation results by the iterative steps and the satisfied results would be obtained after about six rounds of iterations.
Algorithms ; Humans ; Imaging, Three-Dimensional ; Liver ; diagnostic imaging ; Models, Theoretical ; Tomography, X-Ray Computed

0.05).Conclusion The maximal slow-phase velocity induced by bithermal caloric test failed to decline with aging,implying that the functions of the horizontal semicircular didn't decline with aging.

Objective To compare prognosis of esophageal cancer patients with simple radiation or chemoradiotherapy.Methods Retrospective analysis 266 cases of esophageal cancer patients from June 2005 to June 2007 of,including 128 with simple radiotherapy,138 with chemotherapy during the same period,157 cases of general radiotherapy,intensity-modulated radiotherapy,109 cases of Kaplan-Meier method for calculation of survival,Log-Rank method on the clinical factors of single factor analysis,Cox regression model with factor analysis.Two groups,clinical material and adverse reaction were compared with chi-square test.Results The median survival time of the radiation group was 25 months,chemoradiotherapy group of the median survival time was 28 months.Follow-up with 1,3,5 years were 231,106,82 cases.The 1,3,4 years OS rate were 86.8 ％ (200/231),12.8 ％ (14/106),9.0 ％ (7/82).Disease-free survival (DFS) rates were 39.8 ％ (92/231),7.9 ％ (8/106),15.8 ％ (13/82).No local relapse survival (LRFS) rates were 30.8 ％ (71/231),16.2 ％ (17/106),23.7 ％ (19/82).No distant metastasis (DMFS) survival rates were 47.0 ％ (109/231),11.3 ％ (12/106),13.9 ％ (11/82).Single factor analysis results show that age,disease length,X-ray parting,different radiation method were 5 years OS independent prognostic factors.Age,disease length were DFS independent prognostic factors.Lesion length,different radiation method were LRFS independent prognostic factors for survival,lesion length and X-ray parting were without distant metastases independent prognostic factors for survival.Multiple factors analysis results showed that age,disease length,pathological type were 5 years OS related factors,and age,disease length,different treatment methods were DFS related factors,only lesions length was DMFS related factors,lesion length,different chemotherapy method was DMFS related factors of survival.The rate of serious adverse reaction of the chemoradiotherapy group was higher than radiotherapy group,the difference had statistical significance.Conclusion The chemoradiotherapy increase DFS rate,and at the same time,the incidence of adverse reaction also increases,but 5 years OS rate doesn't increased obviously.

Objective To evaluate the effect of 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) on S.epidermidis biofilms.Methods S.epidermidis was cultured on cover glasses,with or without thepresence of ALA at 50 mmol/L for 16 hours followed by the exposure to different doses (100,200,300 J/cm2) of red light.S.epidermidis receiving neither pretreatment nor irradiation served as the negative control.Subsequently,confocal laser scanning microscopy (CLSM) was used to observe the structure and evaluate the biological activity of S.epidermidis biofilms; colony forming units (CFUs) of S.epidermidis were counted for the evaluation of killing effect of ALA-PDT; scanning electron microscopy (SEM) was used to observe the morphological structure of the biofilms.Results The number of colony forming units per milliliter (CFU/ml) was (210 ± 7.55) × 105,(91 ± 1.53) × 105,(16 ± 1.52) × 105 for S.epidermidis pretreated with ALA followed by irradiation with red light at 100,200 and 300 J/cm2 respectively,significantly different from untreated S.epidermidis ((388 ±8.89) × 105,all P ＜ 0.01) and S.epidermidis irradiated with red light only.Increased ratio of dead to live cells was observed in ALA-pretreated S.epidermidis irradiated with red light at 100,200 and 300 J/cm2compared with untreated S.epidermidis (1.254 ± 0.096,1.301 ± 0.160 and 3.410 ± 1.140 vs.0.358 ± 0.057,all P ＜ 0.01) and S.epidermidis irradiated with red light only.SEM showed that the biofilm structure was loose and obscure in S.epidermidis treated with ALA-PDT,and even disappeared with S.epidermidis distributed in single colonies when the dose of red light was 300 mJ/cm2.Conclusion ALA-PDT shows a potential bactericidal activity against S.epidermidis in biofilms,which can not only reduce biofilm vitality,but also damage biofilm structure.

Objective To investigate the role of AGE-RAGE system on intimal hyperplasia in autogenous vein graft of diabetic rats.Methods The experiments were performed on 40 male Sprague-Dawley rats which divided into two groups:diabetes group and control group.Autogenous vein graft model was established in all rats.Specimens were harvested 7 days and 14 days after surgery for histological examination,and RAGE,NF-?B p65 and VCAM-1mRNA were measured by semi-quantitative reverse transcription-PCR.Western Blotting and immunohistochemistry were used to detect the protein expression of RAGE,NF-?B p65 and VCAM-1.At the same time,the levels of serum AGE were tested.Results Compared with non-diabetic rats of control group,the intimal hyperplasia of vein graft in diabetic rats obviously increased(P

Objective To investigate the effect of nicardipine on the hepatic blood flow in the patients undergoing cardiac valve replacement with cardiopulmonary bypass (CPB).Methods Twenty-six patients of both sexes,aged 30-64 yr,weighing 50-90 kg,with New York Heart Association Ⅱ or Ⅲ,of American Society of Anesthesiologists physical status Ⅱ or Ⅲ,scheduled for elective mitral or aortic valve replacement,were randomly divided into either nicardipine group (group P,n =13) or control group (group C,n =13) using a random number table.Transesophageal echocardiography was used to measure the indexes of blood flow in the hepatic vein.Nicardipine 0.2-0.5 μg · kg-1 · min-1 was infused intravenously starting from beginning of CPB,and the infusion was stopped at termination of CPB in group P.After induction of general anesthesia,at 30 min after beginning of CPB,at 10 min before termination of CPB,and at 30 min after termination of CPB,the diameter of the right and middle hepatic veins (DR and DM),blood flow index in the right hepatic vein (QIR),blood flow index in the middle hepatic vein (QIM),and total blood flow index in the hepatic vein (QIR+M) were recorded,and the percentage of QIR+M in cardiac index (CI) (QIR+M/CI) or in QICPB (QIR+M/QICPB) was calculated.Before operation,and at 1 and 2 days after operation,blood samples were obtained from the median cubital vein for determination of total bilirubin,alanine aminotransferase,and aspartate aminotransferase (AST) levels in serum.Results Compared with group C,the serum levels of AST at 1 day after operation and serum levels of AST at 1 day after operation were significantly decreased (P＜0.05),and no significant change was found in DR,DM,QIR,QIM,QIR+M,QIR+M/CI and QIR+M/QICPB at each time point in group P (P＞0.05).Conclusion Nicardipine (0.2-0.5 μg · kg-1 · min-1) infused intravenously during CPB exerts no effect on the hepatic blood flow,and it is not related to the improvement in hepatic function in the patients undergoing cardiac valve replacement.

Objective To evaluate the effect of sevoflurane-based anesthesia on the interventricular synchronization in the patients undergoing coronary artery bypass grafting (CABG) with cardiopuhnonary bypass (CPB).Methods Twenty-four Amnerican Society of Anesthesiologists physical status Ⅱ or Ⅲ patients,aged 52-75 yr,with body mass index of 17-31 kg/m2,with body surface area of 1.7-2.2 m2,of New York Heart Association Ⅱ or Ⅲll,with left ventricular ejection fraction (LVEF) ≥45％,scheduled for elective CABG with CPB,were divided into 2 groups (n=12 each) using a random number table:propofol combined with remifentanil anesthesia group (group C) and sevoflurane combined with propofol and remifentanil anesthesia group (group S).After induction of general anesthesia,the patients were en-dotracheally intubated and mechanically ventilated.Anesthesia was maintained by Ⅳ infusion of propofol,remifentanil and cisatracurium,and the cerebral state index value was maintained at 40-60.In group S,the patients inhaled sevoflurane (the end-tidal concentration was 1.80％ for 50-59 yr and 1.60％ for 60-75 yr) for 60 min starting from 15 min after termination of CPB.After induction of anesthesia and before splitting of sternum,immediately before inhaling sevoflurane and at 30 and 60 min of sevoflurane inhalation,heart rate,cardiac index,LVEF,right ventricular eject fraction,QRS width and interventricular mechanical delay were recorded,and the occurrence of interventricular dyssynchrony was recorded.Results There were no significant differences between group C and group S in the heart rate,cardiac index,LVEF,right ventricular eject fraction,QRS width,interventricular mechanical delay or incidence of interventricular dyssynchrony (P＞0.05).Conclusion Sevoflurane-based anesthesia exerts no marked effect on interventricular synchronization in the patients undergoing CABG with CPB.

BACKGROUND: Anemia after kidney transplantation has a clinical incidence rate of 30%-40%, is the important risk factor for cardiovascular diseases and kidney failure after kidney transplantation and is also the independent prediction index of patient's death. OBJECTIVE: To analyze the factors related to anemia after kidney transplantation. RESULTS AND CONCLUSION: In the anemia group (n = 225, 27.2%, aged 26-65 years), the incidence rate of anemia in female and male patients was 23% and 37%, respectively (P < 0.05), 46 patients had hypertension and used angiotensin-converting enzyme inhibitor or angiotensin Ⅱ receptor antagonist and 16 patients had chronic erosive gastritis or upper gastrointestinal tract ulcer, with the human survival rate of 85.3% and kidney failure rate of 25.3%. In the non-anemia group (n = 601, 72.8%, 405 males, 196 females, aged 18-71 years), 35 patients had hypertension and used angiotensin-converting enzyme inhibitor or angiotensin Ⅱ receptor antagonist and 14 patients had chronic erosive gastritis or upper gastrointestinal tract ulcer, with the human survival rate of 92.1% and kidney failure rate of 12.6%. There was significant difference in above-mentioned indices between anemia and non-anemia groups (P < 0.05). These results suggest that gender, age, kidney function, digestive tract disease history, and drug application are closely related to anemia after kidney transplantation.

Objective To evaluate the effect of dexmedetomidine on left ventricular function in patients undergoing coronary artery bypass grafting (CABG) by transesophageal echocardiography (TEE).Methods The study was a prospective,randomized and placebo-control clinical trial.Eighty patients undergoing CABG with cardiopulmonary bypass (CPB) were divided into dexmedetomidine group (group D)and control group (group C) by random digits table method with 40 cases each.A loading dose of dexmedetomidine 0.5 μg/kg was injected intravenously 10 min after induction followed by infusion at 0.4 μ g/(kg· h) until the end of operation in group D,while equal volume of normal saline was given in group C.Left ventricular function was assessed by transesophageal echocardiography before the infusion of dexmedetomidine (T1),at the end of the infusion of loading dose (T2),before CPB (T3) and at the end of the operation (T4).Results Compared with those at T1,left ventricular ejection fraction and fractional area change decreased significantly [(58.0 ± 12.0)％,(60.0 ± 9.6)％ vs.(63.0 ± 8.6)％ and (46.0 ± 9.3)％,(48.0 ± 8.4)％ vs.(51.0 ± 6.7)％] (P ＜ 0.05 or ＜ 0.01),E/A ratio increased significantly (1.05 ± 0.27,1.07 ±0.31 vs.0.98 ±0.19)(P ＜0.05 or ＜0.01) and myocardial performance index (MPI) decreased significantly (0.46 ± 0.14,0.45 ± 0.12 vs.0.51 ± 0.14) (P ＜ 0.05) at T2 and T3 in group D,while stroke volume was not significantly changed (P＞ 0.05).Compared with that in group C,E/A ratio and rapid filling fraction in group D was significantly higher [1.06 ± 0.18 vs.0.97 ± 0.18,(62.0 ± 7.1)％ vs.(58.0 ± 7.3)％],and S/D ratio and MPI was significantly lower at T4(1.17 ± 0.21 vs.1.29 ± 0.22,0.43 ± 0.15 vs.0.50 ± 0.15),and there were significant differences (P ＜ 0.05).There was no difference in the parameters indicating left ventricular systolic function (P ＞ 0.05).Conclusions Dexmedetomidine restrains left ventricular systolic function in the patients undergoing CABG,but does not decrease the cardiac output,and improve relaxation dysfunction of left ventricular diastolic function.Global left ventricular function is improved by dexmedetomidine after CABG.

Objective To study the bone turnover and its related molecular mechanism in STZ-induced diabetic rats. Methods Of 30 male SD rats studied, 15 were induced diabetics by intravenous injection of streptozotocin (50 mg/kg)and fed for 8 weeks. After the sacrifice of both the diabetic and control groups, serum Ca, P, alkaline phosphatase (ALP), and osteocalcin were determined, and 24 h urinary Ca and urinary cross-linked N-telopeptide of type Ⅰ collagen (NTx)and creatinine (Cr)ratio were also determined. The left tibia was dissected for bone histomorphometry analysis. Right femur and lumbar vertebrae (L1-L4) were reserved for bone mineral density (BMD) determination. The right tibia was separated for the study of bone tissue RANKL/osteoprotegerin, Core binding factor 1 (Cbfa1) ,osterix and osteocalcin mRNA level which was performed by real-time quantitative reverse transcription polymerase chain reaction assay. Results No significant difference was found in serum Ca, P, and ALP levels between 2 groups of rats. ST-Z-induced diabetic rats were characterized by extreme hyperglycemia, marked weight loss, polyuria, and hypercalciuria. A low-turnover osteopenia was evidenced in diabetic rats by decreased BMD in both femur [(0. 099±0.013) vs (0. 139 ± 0.013 g/cm~3) , P < 0.01] and lumbar vertebrae [(0. 107±0.011)vs (0. 149±0.009) g/cm~3, P<0.01] , reduced serum osteoealcin level [a marker of formation, (3.03±0.52) vs (6. 18±0.71) ng/ml ,P<0. 01]) ,decreased urine NTx/Cr ratio [(5. 67±0.86) vs (5.23±0.98) nmol/g Cr, P<0. 05], decreased trabeeular volume and thickness, and reduced bone label surface and bone formation rate [(0. 44±0. 11) vs (0. 78±0. 14) μm/d,P<0. 01] by bone dynamic study. The RANKL/ osteoprotegerin [(0.57±0.11)vs (0.89±0.13) ,P<0.01] ,osterix [(1.93×10~(-4)±0.65×10(~-4))vs (4.19×10~(-4)± 0.71×10~(-4)) ,P<0.01] ,Cbfa1 [(26.68×10~(-4)±6.53×10~(-4))vs (37.21×10~(-4)±7.14×10~(-4)) ,P<0.01] ,and osteocalcin [(2.25×10~(-4)±1.19×10~(-4))vs (3.43×10~(-4)±1.63×10~(-4)) ,P<0.01] mRNA expressions were declined in the bone tissue of the tibia in the ST-Z-induced diabetic rats, as compared with the control. Conclusion A low-turnover osteopenia is evidenced in STZ-induced diabetic rats by significant decrease of both osteoclastic marker(RANKL/ osteoprotegerin)and osteoblastic marker (osterix ,Cbfa1 ,osteocalcin)mRNA levels in tibia.