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Objective To study the morphology and fractal characterization of UHMWPE wear particles by simulation experiment on knee joint, analyze the classification characteristics of wear particles and discuss the correlation between fractal dimension and wear state. Methods The knee joint simulator was used to realize the knee joint wear motion. The forged CoCrMo alloy and UHMWPE were selected as artificial joint prosthesis materials. The wear particle extraction was based on ISO 17853. The automatic extraction and fractal identification system of wear particles were used to investigate fractal characteristics of wear particles. Three kinds of models were established to classify and recognize wear particles, by using the meshing method, cluster analysis and genetic simulated annealing algorithm, respectively. Results The fractal characteristics of UHMWPE single wear particles was very obvious. The fractal dimension calculated by radar fractal method decreased, during the transition from the larger size of strip debris to the smaller size of roundness debris, and the fractal dimension D of spherical debris was close to zero. The weighted sum of squared error values of fractal dimension for wear particle population classification was the smallest by the model of genetic simulated annealing algorithm, and the clustering feature was very obvious. When the wear cycles were low, the large fractal dimension of strip, needle and fibrous abrasive debris with larger fractal dimension had the largest proportion, and the main abrasion modes were the ploughing and spalling wears. With the extension of wear period, the proportion of wear particles with large fractal dimension decreased, and the proportion of flaky, blocky and near-spherical wear particles with low fractal dimension increased clearly. The wear mechanism changed to the fatigue and adhesive wear, and the wear state transited to the composite wear period. During the stable wear period, the proportion of all kinds of abrasive grains changed little. Due to the increase in the number of small particles, the fractal dimension decreased in stable wear state. Conclusions Based on the improved radar graph method, the fractal dimension of wear particles with different profiles could be obtained by automatic extraction and fractal identification system of wear particles. The research findings can be used in shape extraction, fractal dimension calculation and parameter statistics, as well as providing a new digital analysis tool for identification and diagnosis for wear particles of artificial prosthesis.
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Objective To evaluate the efficacy, safety and risk factors of endoscopic treatment for patients with early gastric cancer. Methods A retrospective study was conducted in a single center and data was collected from 186 early gastric cancers in 168 pathologically confirmed patients who received endoscopic treatment in Peking Union Medical College Hospital from January 2006 to December 2015. The cases were divided into different groups according to indications of endoscopic treatment. The curative resection rate and complication rate were analyzed. Post-resection outcomes were evaluated by long-term surveillance. Results The curative resection rate was 86. 9%( 73/84) in the group with absolute indications, 61. 7%(50/81)in the group with expanded indications, and 33. 3%(7/21) in the group beyond indications (P＜0. 01). Multivariate analysis revealed that the significant independent predictors for curative resection included lower third location of stomach, no ulceration,≤2 cm at diameter, no adhesion, and well-differentiation in histopathology. In the expanded indications group, discordance of differentiation type and deeper invasion mainly resulted in non-curative resection in en bloc lesions. The rate of bleeding and perforation was 4. 8%( 9/186) and 3. 8%( 7/186), respectively. The perforation rate was significantly lower in the lesions located in the lower third of stomach, without adhesion or performed by en bloc resection. During a median follow-up period of 22. 3 months, 154 patients were followed successfully. The incidence of synchronous and metachronous gastric cancers in curative resected lesions was 7. 5%( 8/106) and 0. 9%(1/106), respectively. Conclusion Endoscopic resection is an optimal treatment with high curative resection rate for early gastric cancer patients with absolute indications. Patients with expanded indications should take precise preoperative evaluation to avoid higher risk of non-curative resection endoscopically. Close follow-up is necessary for synchronous and metachronous gastric cancers after endoscopic resection.
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Objective To explore the clinical effect of patients of oral and maxillofacial space infection treated with improved closed negative pressure drainage combined with hyperbaric oxygen, and the possibility of using this method to decrease the hospital expenses. Methods 156 patients with oral and maxillofacial space infection were divided into control group, closed negative pressure drainage group and improved closed negative pressure drainage combined with hyperbaric oxygen group by random number table. 52 patients in each group. The granulation tissue growth time, the healing of wound, clinical effect of the 8thday, hospitalization days, wound healing time, antibiotic cost, average cost in hospital were recorded after treatment. Results The average wound healing time of patients in improved closed negative pressure drainage combined with hyperbaric oxygen group was(6.06 ± 0.23)days, while the granulation tissue growth time was(16.13 ± 2.89)days, both of them were much shorter than the control group[(15.46 ± 4.68)days and(28.60 ± 3.50)days respectively],as well as the closed negative pressure drainage group [(7.43 ± 0.75) days and (22.67 ± 4.34) days respectively], and the differences were statistically significant which the F values equaled to 6.213 and 8.451, P values all less than 0.05. The total healing rate of patients in closed negative pressure drainage group and improved closed negative pressure drainage combined with hyperbaric oxygen group were both 100.00%(52/52), the difference was statistically significant compared with control group (χ2=6.89, P<0.05). The average hospitalization days of the patients in the closed negative pressure drainage group and improved closed negative pressure drainage combined with hyperbaric oxygen group were (8.20 ± 1.49) days and (7.45 ± 0.42)days, the antibiotic cost were(5 068.34 ± 1 074.68)RMB and (5 001.00 ± 456.00) RMB, the average total cost were (9 457.43 ± 647.23)RMB and (9 249.00 ± 367.00)RMB, all these indexes were much lower that which in control group[(18.40 ± 5.89)days,(21 000.43 ± 2 036.48) RMB and (31 000.66 ± 2 711.36) RMB], and the differences were statistically significant, F values equaled to 15.221, 29.434 and 81.220 each, P values were all less than 0.01. Conclusions Improved closed negative pressure drainage combined with hyperbaric oxygen method could improve the clinical effect of patients with oral and maxillofacial space infection, speed up the granulation tissue, shorten the in-hospital time as well as reduce the medical cost.
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Objective To analyse the negative predictive value of endoscopic ultrasonography (EUS)for detecting pancreatic cancer and to evaluate its clinical value of ruling out malignant cancer. Methods The medical records of patients who were referred to pancreatic EUS with suspected pancreatic cancer and normal EUS findings from January 2005 to December 2013 were reviewed. Moreover,the follow-up data were reviewed to evaluate whether the patient developed pancreatic cancer or other malignancy that could cause the abnormality mentioned above. The follow-up data were obtained by examining the inpatient/outpatient records as well as conducting brief telephone interviews. Results A total of 122 patients were in-cluded in our study. The follow-up data of 108 were accessible,and the mean follow-up period was 52. 4 months. One patient was histopathologically diagnosed as having pancreatic cancer 6 years after the proce-dure,and 107 other patients with a normal pancreatic EUS were free of pancreatic cancer as well as other malignancy during the follow-up period. The negative predictive value of pancreatic EUS was 99. 1%(107/108). Conclusion For patients with suspected pancreatic cancer but normal EUS findings,there is no need for further exploratory surgery. However,if there is a high suspicion of malignancy in the pancreas,a repeat-ed EUS is necessary in case of a false negative EUS result.
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Objective To evaluate magnifying endoscopy combined with narrow-band imaging ( ME-NBI) for diagnosis of early gastric cancer (EGC).Methods A total of 150 focal lesions from 143 patients over 35 years old identified by white light endoscopy (WLE) from March 2010 to December 2010 in our tertiary referential institution were recruited in the prospective study with written informed consent.Focal lesions were defined as any small local mucosa with abnormal shape or color based on an assessment of findings of WLE without any specified criteria, including superficial, depressed and elevated lesions.The patients with local advanced gastric cancer, submucosal lesions and history of gastrectomy were excluded from the study.All the patients received ME-NBI.Based on literature, national criteria of early diagnosis with ME-NBI were established.All the lesions underwent biopsy and pathological examination.Diagnostic accuracy of ME-NBI for EGC was assessed with reference to histopathology.Results In 150 focal lesions, 19 were pathologically diagnosed as EGC, 8 of which were treated by endoscopic resection and 11 were resected surgically.The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of conventional WLE for diagnosing EGC were 94.7%, 53.4%, 22.8%, 98.6% and 58.7%, respectively.The counterparts of ME-NBI for diagnosing EGC were 73.7%, 99.2%, 93.3%, 96.3% and 96.0%, respectively.The diagnostic accuracy of ME-NBI was significantly better than that of conventional WLE (96.0% vs.58.7%, P＜0.05).With regard to the findings of EGC on ME-NBI, irregular or absent microsurface pattern and microvascular pattern were characteristic features of EGC.Conclusion Conventional WLE is still an important and mandatory screening modality, which is significant for further procedures of suspected lesions, preferably accompanied with biopsy.ME-NBI achieved superior accuracy in the differential diagnosis of focal lesions detected with conventional WLE, but needs further verification.
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Objective To evaluate endoscopic ultrasonography (EUS) for TN restaging and predicting response to advanced gastric cancer after neoadjuvant chemotherapy. Methods A total of 22 patients,15 males and 7 females, mean age 64 (36-80 years ), with advanced gastric cancer were recruited to the study from June 2007 to December 2009 with written informed consents. All patients underwent 3 cycles of neoadjuvant chemotherapy ( Folfox 6 ), and subsequent surgery ( R0 resction) in 3-4 weeks after chemotherapy. EUS was performed 1-2 weeks before and 1-2 weeks after chemotherapy. EUS TN staging was compared with pathological findings. The correlation of peri-chemotherapy EUS TN staging with postoperative pathological response was evaluated. Results After chemotherapy, the overall accuracy of EUS T staging was 63.6% (14/22), with overstaging (36. 4%, 8/22) more frequent than understaging (0). The overall accuracy of N staging was 54. 5% (12/22) with 4 ( 18. 2%, 4/22) overstaging and 6 ( 27. 3%, 6/22 ) understaging. EUS revealed T and/or N downstaging ( concyrrence of T and N downstaging was accounted once) after chemotherapy in 10 patients, with 9 T downstaging (4 from T3 to T2, 5 from T4 to T3) and 4 N downstaging (4 from N1 to N0). TN downstaging was correlated with pathological response, with 7 patients achieving pathological response 2 and 1 patient 3. Conclusion T and N restaging by EUS after neoadjuvant chemotherapy in patients with locally advanced gastric cancer is not accurate enough. However, T and/or N downstaging confirmed by EUS is well correlated with a better degree of pathological response to chemotherapy.
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@#Objective To determine the utility of computed tomographic (CT) enteroclysis for characterization of the status of the anastomotic site in patients with Crohn's disease (CD) who have previously undergone ileocolic resection. Methods Totally 31 CD patients who had previously undergone ileocolic resection were enrolled in the study. After having been orally administered with isosmotic mannitol, the patients received CT scanning including plain scan, arterial phase scan, and portal venous phase scan. The abnormal CT findings were analyzed based on portal venous phase images. CT enteroclysis findings in 31 patients were evaluated by two radiologists in consensus. Endoscopic findings, histopathologic findings, and/or the Crohn's disease activity index (CDAI) were used as the reference criteria. Associations between CT enteroclysis findings and anastomotic site status were assessed. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CT enteroclysis for the diagnosis of normal anastomosis versus anastomotic recurrence were estimated. Results Twenty-six cases and 5 cases were diagnosed as disease recurrence and normal anastomosis, respectively. In the disease recurrence group, 11 patients (42%) had lymphadenopathy (diameter＞ 1 cm) and 8 patients (31%) had peri-anastomotic fistulas, which were absent in normal anastomosis group, but the difference was not significant Anastomotic wall thickening more than 6 mm, marked mucosal enhancement, stratification, and peri-anastomotic stranding were found in 16 (62%), 19 (73%), 14 (54%), and 20 (77%) cases, respectively, in disease recurrence group, which were absent in normal anastomosis group ( all P ＜ 0.05 ). When the diagnosis of anastomotic recurrence was based on more than two of the following six variables, including lymphadenopathy, peri-anastomotic fistulas, anastomotic wall thickening more than 6 mm, marked mucosal enhancement, stratification, and peri-anastomotic stranding, its sensitivity, specificity, postive predictive value, negative predictive value, and accuracy yielded 88%, 100%, 100%, 63%, and 90%, respectively. The diagnostic accuracy of anostomotic stenosis with CT was only 53%. Conclusion CT enteroclysis yields objective and relatively specific morphologic criteria that help differentiate between recurrent disease and normal at the anastomotic site after ileocolic resection for CD.
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Objective To investigate the diagnostic value of capsule endoscopy (CE), CT enterography (CTE), ileocolonoscopy and small bowel follow through (SBFT) for small bowel Crohn's disease (CD). Methods Fifty-seven consecutive patients with CD underwent ileocolonoscopy, CTE, CE, and SBFT. It included the presence of the following symptoms and signs: abdominal pain, weight loss,diarrhea, fever and positive fecal occult blood test. The location and the characteristics of intestinal and extra-intestinal lesions detected by four techniquks were compared. The proportions of patients with positive findings using each examination were compared. Results Of the 57 patients, 50 underwent ileocolonoscopy, terminal ileum lesion was found in 33 patients (66. 00% ), the remaining 17 (34.0%)were normal; among 34 patients who had CTE, 29 of small bowel lesion were found (85. 29% ); CE were performed in 27 patients, due to prolonged gastric transit one time, the capsule did not reach the cecum in one patient during battery lifetime. CE showed small bowel lesion in 26 patients (96.30% ); SBF was performed in 39 patients and 26 of small bowel lesion were detected (66. 67% ). CE had the highest diagnostic yield for CD and ileocolonoscopy had the lowest, and there were statistically significant difference among the 4 examinations (P = 0. 006 ). The combinded positive rates of two methods were: CE + CTE 92. 86% (13/14), SBFT + CTE 90. 91% (20/22), CE + ileocolonoscopy 95. 65% (22/23), CE + SBFT100% (17/17), ileocolonoscopy + CTE 89. 66% ( 26/29 ), ileocolonoscopy + SBFT 77.78% ( 28/36 ), but there were no significant differences between each two examinations. Conclusion CE, CTE have a higher yield in depicting mild to moderate finding of CD than SBFT. CE is better for assessing early mucosal disease,whereas CTE is better for detecting transmural and extraluminal abnormalities. Most important, CE plus CTE may depict nonobstructive CD of the small bowel when conventional techniques such as ileocolonoscopy or SBFF have negative or inconclusive finding. CE provides us explanations for the symptoms of patients, decision to follow up or therapy.
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Objective To analysis the features of Montreal classification,serum markers,treatment and prognosis of Chinese patients with Crohn's disease(CD),and to estimate the relationships between clinical classification and anti-sarccharomyces cerevisiae antibody(ASCA),treatment and prognosis.Methods A retrospective study of 102 consecutive definite CD eases were performed and all subjects were classified into subtypes according to Montreal classification.The results of ASCA,extra-intestinal manifestation,treatment and disease behavior at follow-up were recorded and compared among different subtypes.Results The A2 subtype(52.9%)was dominated in Chinese CD patients.Ileocolon location(40.2%)and stricture lesion (53.9%)were common.The complication rate was dependent on disease course(P＜0.05),and intestinal fistula was associated with disease location(P=0.074).B1 subtype had higher progressive rate than B2 subtype(P=0.018).ASCA was not associated with disease loeation,disease behavior,treatment and disease progression(P＞0.05).Conclusions Crohn's disease mainly attack young people with male predominance.Early-onset CD patients have higher ASCA positive rate and disease progressive rate.The disease behavior progresses associated with disease course,and the rate of complication and the increase of surgery.The penetrating behavior is the main cause for surgery.Montreal classification is useful to predict the disease course,the need for surgery as well as the prognosis.
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Objective To analyze the characteristics of EUS imaging in the patients with autoimmune pancreatitis(AIP).Methods Eleven cases of AIP were studied retrospectively,and features of EUS were analyzed.Results EUS revealed diffuse or focal enlargement of pancreas along with hypoechoic parenchyma and a wavy margin.In addition to dilation,the bile duct had a prominently thickened wall with homogenous mild hypoechoic image.Peripancreatic lymph nodes could be enlarged.No pancreatic duct dilation.calcification or cysts were found.No peripheral vessels were involved.Conclusion EUS could demonstrate specific images which is helpful in diagnosis of AIP.
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Objective To evaluate the value of intraduetal ultrasonography (IDUS) in diagnosing biliary and pancreatic disorders. Methods The findings by endoscopic retrograde cholangiopancreatography (ERCP) and IDUS from 19 patients with suspected biliary and pancreatic disorders from July 2006 to August 2007 in our hospital were analyzed retrospectively. Results Of the 19 patients, 17 had obstructive jaundice (including 6 eases of cholangiocarcinoma, 2 pancreatic adenocareinoma, 2 gallbladder carcinoma, 2 chole-docholithiasis with bile duct stricture, 2 autoimmune pancreatitis, 1 papillary adenocarcinoma, 1 papillary adenoma, and 1 sclerosing cholangitis) and 2 intraduetal papillary mueinous tumor (IPMT). The diagnosis was confirmed by surgery and pathological findings in 11 patients. The diagnostic accuracy of ERCP and IDUS was 73. 7% (14/19) and 84. 2% (16/19), respectively, and that of ERCP combined with IDUS was 89. 5% (17/19). The sensitivity and specificity of ERCP to differentiate benign bile duct strictures from ma-lignant ones were 100. 0% (11/11) and 83.3% (5/6), respectively; and those of IDUS were 100. 0%(11/11) and 100. 0% (6/6), respectively. The sensitivity and specificity of ERCP in diagnosing cholan-gioeareinoma were 83.3% (5/6) and 60% (3/5), respectively; and those of IDUS were 100. 0% (6/6) and 40. 0% (2/5), respectively. Conclusion Combination of ERCP with IDUS can improve the diagnostic accuracy of pancreaticobiliary disorders. Additionally, IDUS shows higher sensitivity and specificity in differ-entiation between benign and malignant bile duct strictures, but it is still difficult to identify the etiologic factors of malignant bile duet strictures by IDUS.
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<p><b>OBJECTIVE</b>To explore new methods for the early diagnosis of pancreatic cancer through detection of K-ras and p53 mutations in pancreatic juice and stool.</p><p><b>METHODS</b>201 patients in PUMC Hospital from 1994 - 2000 and 60 control individuals were enrolled in this study. K-ras point mutation was detected by PCR-RFLP while p53 mutation was detected by PCR-SSCP.</p><p><b>RESULTS</b>K-ras mutation was found in pancreatic juice in 87.8% (36/41) of pancreatic cancer patients and 23.5% (4/17) of benign pancreatic disease patients. In 261 stool specimens, amplification found mutations successfully in 235 patients (90%). K-ras mutation was found in stool in 88% (66/75) of pancreatic cancer patients, 51.1% (24/47) of benign pancreatic disease patients and 19.6% (9/46) of normal individuals. p53 mutation was found in pancreatic juice in 47.4% (18/38) of pancreatic cancer patients and 12.5% (2/16) of benign pancreatic disease patients. p53 mutation was found in stool in 37.1% (23/62) and 19.1% (4/21) of chronic pancreatitis patients.</p><p><b>CONCLUSION</b>K-ras mutation in pancreatic juice has higher diagnosis sensitivity and specificity, and therefore may be used as a supplement in the diagnosis of pancreatic cancer. Detection of K-ras mutation combined with p53 mutation in stool can aid in the screening of pancreatic cancer.</p>
Subject(s)
Humans , Feces , Chemistry , Genes, p53 , Genes, ras , Mutation , Pancreatic Juice , Metabolism , Pancreatic Neoplasms , Diagnosis , Genetics , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Polymorphism, Single-Stranded ConformationalABSTRACT
20 cup-years) were found to have increased risk for pancreatic cancer (OR 3.681; 95%CI 1.604～8.443). Daily diet with high meat intake was also linked to pancreatic cancer. About 18.49% of the pancreatic cancer patients had diabetes mellitus compared to the control group of 5.77% (P=0.0003). Typical symptoms of pancreatic cancer were anorexia, upper abdominal pain, bloating, jaundice and weight loss. The high risk score of the two groups were 80.6 (95% CI 74.9～86.3) and 7.4(95% CI 6.0～8.7) (P
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Objective To retrospectively evaluate the diagnostic accuracy of endoscopic ultrasonog raphy ( EUS) in pancreatic cancer, analyze the value of EUS in measurement of tumor diameters, TNM staging, and investigate the effectiveness of endoscopic ultrasonography-guided fine needle aspiration ( EUS-FNA). Methods All the data adopted from the patients underwent EUS in PUMC Hospital between 1997 and 2003. Eighty-eight patients with a final diagnosis of pancreatic cancer (56 is proven by surgical pathology, 10 by surgical findings and 22 by clinical diagnosis) and 47 patients with a final diagnosis of benign pancreatic disease were included and analyzed. Results The sensitivity, specificity, accuracy, positive and negative predictive values of EUS in the diagnosis of pancreatic cancer were 95. 5% , 59. 6% , 83. 0% , 81. 6% and 87. 5% respectively. Tumor diameters measured by EUS (2. 8?1. 0)cm were obviously smaller than those by surgical findings (6.5 ? 2. 9) cm. For TNM stage, compared with surgical findings, the accordance rates of EUS in T and N staging were 43. 1% and 61. 1% respectively. The accuracy of EUS-FNA in the diagnosis of pancreatic cancer was 76. 5% ( 13/17). Conclusions The sensitivity of EUS in pancreatic cancer is highest among all imaging procedures. Tumor diameters measured through EUS are smaller than those by surgery.
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Objective To evaluate the value of clinical data and various methods of diagnostic imaging in the patients with pancreatic cancer. Methods Two hundreds and fifty-six patients with pancreatic cancer admitted into Peking Union Medical College Hospital between 1996 and 2004 were included. The clinical symptom and the accuracy of various imaging methods (B-US, CT, ERCP, EUS, DSA and MRI) in assessing pancreatic carcinoma were analyzed. Results Weight lost was the most common symptom in 79% of patients with pancreatic carcinoma. Jaundice was mostly seen in patients with pancreatic head carcinoma. Upper abdominal pain was in 86% of patients with carcinoma in pancreatic body and tail. The diagnostic accuracies of B-US, CT, ERCP, EUS, DSA and MRI were 83% , 89% , 90% , 91% , 82% and 79% respectively. Conclusion B-US and CT scanning should be undergone in patients with abdominal pain, jaundice and weight lost who were suspected to have pancreatic carcinoma. Further imaging techniques such as EUS, ERCP and MRI should be advised in patients highly suspected to have pancreatic carcinoma, in spite of the results of B-US and CT were negative.