Objective To evaluate the diagnostic accuracy of the aberrant methylation of genes in stool for colorectal tumor. Methods Databases including The Cochrane Library, PubMed, EMbase, CBM, Web of Science, CNKI and WanFang Data were searched to collect the diagnostic trials on the aberrant methylation of genes in stool for colorectal tumor published from January 1990 to February 2012. QUADAS items were used to evaluate the quality of the included studies, and the meta-analysis was conducted using Meta-Disc 1.4 software. Results A total of 32 studies involving 3 951 patients were included. The results of meta-analysis showed that, for detecting the colorectal tumor, the weighted sensitivity, specificity, diagnostic odds ratio (DOR), area under the summary receiver operating characteristic (SROC) curve and Q were 92% (95%CI 91% to 93%), 63% (95%CI 61% to 65%), 20.79 (95%CI 15.13 to 28.57), 0.861 9 (SE=0.020 4), and 0.792 6 (SE=0.019 8), respectively. For detecting the colorectal cancer, the weighted sensitivity, specificity and area under the curve (AUC) were 91% (95%CI 89% to 92%), 75% (95%CI 73% to 77%), and 0.900 7, respectively. For detecting the colorectal adenoma, the weighted sensitivity, specificity and AUC were 79% (95%CI 76% to 83%), 75% (95%CI 73% to 77%), and 0.845 7, respectively. Conclusion With high sensitivity (92%) and moderate specificity (63%), aberrant methylation of genes in stool can be used as an optional noninvasive method for the diagnosis of colorectal tumor.
Objective To explore the histochemical staining for distinguishing and local izing nerve fibers and fascicles at histological level in three-dimensional reconstruction of peri pheral nerves. Methods The right median nerve was harvested from one fresh cadaver and embedded in OCT compound. The sample was serially horizontally sl iced with 6 μm thickness. All sections were stained with Karnovsky-Roots method (group A, n=30) firstly and then stained with toluidine blue (group B, =28) and Ponceau 2R (group C, n=21) in proper sequence. The results of each step were taken photos (× 100). After successfully stitching, the two-dimensional panorama images were compared, including texture feature, the number and aver gray level of area showing acetylchol inesterase (AchE) activity, and result of auto microscopic medical image segmentation. Results In groups A, B, and C, the number of AchE-positive area was (21.63 ± 4.06)× 102, (20.64 ± 3.51)× 102, and (20.54 ± 5.71)× 102, respectively, showing no significant difference among 3 groups (F=0.64, P=0.54); the mean gray level was (1.41 ± 0.06)× 102, (1.10 ± 0.05)× 102, and (1.14 ± 0.07)× 102, respectively, showing significant differences between group A and groups B and C (P lt; 0.001). In the image of group A, only AchE-positive area was stained; in the image of group B, myelin sheath was obscure; and in the image of group C, axons and myelin sheath could be indentified, the character of nerve fibers could be distinguished clearly and accurately, and the image segmentation of fascicles could be achieved easier than other 2 images. Conclusion The image of Karnovsky-Roots-toluidine blue-Ponceau 2R staining has no effect on the AchE-positive area in the image of Karnovsky-Roots staining and shows better texture feature. This improved histochemical process may provide ideal image for the three-dimensional reconstruction of peri pheral nerves.
Objective To explore and solve the key technologies of the three dimensional (3D) visual ization reconstruction of functional fascicular groups inside long segmented peri pheral nerve. Methods A 20 cm ulnar nerve from upper arm of fresh adult dead body was embedded by OCT with four pieces of woman’s hair which was used as locating material, then the samples were serially horizontally sl iced into 400 sl ices with 15 μm thickness and 0.5 mm interval. All sl iceswere stained with acetylcholinesterase (AchE) histochemical staining. After that, the 2D panorama images of the same sl ice were obtained with Olympus stereomicroscope and MSHOT MD90 micro figure image device before and after AchE staining. Using the layer processing technique of Photoshop image processing software, the recomposition images including complete 4 location pots were obtained, based on which the algorithm of optimized least square support vector machine (Optimized LS-SVM) and space transformation method was used to fulfill automatic registration. Finally, with artificial assistant outline obtaining, the 3D visual ization reconstruction model of functional fascicular groups of 20 cm ulnar nerve was made using Amira 4.1, and the effects of reverse reduction and the suitabil ity of 3D reconstruction software were evaluated. Results The two-time imaging technique based on the layer process of Photoshop image processing software had the advantages: the image outline had high goodness of fit; the locating pots of merging image was accurate; and the whole procedure was simple and fast. The algorithm of Optimized LS-SVM had high degree of accuracy, and the error rate was only 8.250%. The 3D reconstruction could display the changes of the chiastopic fusion of different nerve functional fascicular groups directly. It could extract alone, merge and combine arbitrarily, and revolve at any angles. Furthermore, the reverse reduction on arbitrarily level dissection of the 3D model was very accurately. Conclusion Based on the two-time imaging technique and computer image layer processing technology, the compute algorithm of auto-registration can be developed and appl ied to 3D visual ization reconstruction of long segmented peripheral nerve. The technological processes is fast, and the reconstruction effect is good.
Objective To investigate the feasibil ity of building the 3D reconstruction of short segment common peroneal nerve functional fascicles based on serial histological sections and computer technology. Methods Five cm of the common peroneal nerve in the popl iteal fossa, donated by an adult, was made into the serial transverse freezing sections(n=200) at an interval of 0.25 mm and 10 μm in thickness per section. Acetylchol inesterase staining was adopted and the nerve fascicles were observed by microscope. 2D panorama images were acquired by high-resolution digital camera under microscope (× 100) and mosaic software. Different functional fascicles were distinguished and marked on each section. The topographic database was matched by image processing software. The 3D microstructure of the fascicular groups of 5 cm common peroneal nerve was reconstructed using Amira 3.1 3D reconstruction software. Results Based on microanatomy and the results of acetylchol inesterase staining, this segmented common peroneal nerve functional fascicles was divided into sensory tract, motor tract, mixed tract and motor-predominating mixed tract. The cross merging was not evident in the nerve fascicles between deep peroneal nerve and superficial peroneal nerve, but existed within the functional fascicles of the deep peroneal nerve and the superficial peroneal nerve. The results of 3D reconstruction reflected the 3D structure of peripheral nerve and its interior functional fascicles factually, which displayed solely or in combination at arbitrary angles. Conclusion Based on serial histological sections and computer technology, the 3D microstructure of short-segment peripheral nerve functional fascicles can be reconstructed satisfactorily, indicating the feasibil ity of building 3D reconstruction of long-segmental peripheral nerve functional fascicles.
【Abstract】 Objective To observe the distribution feature of nerve bundles in C7 nerve anterior and posterior division end. Methods The brachial plexus specimen was harvested from 1 fresh adult cadaver. After C7 nerve was confirmed, the distal end of anterior and posterior division was dissected and embedded by OCT. Then the samples were serially horizontally sliced with each 10 μm deep. After acetylcholinesterase (AChE) histochemical staining, the stain characteristics of different nerve fiber bundles were observed and amount of the nerve fiber bundles were counted under optic-microscope. At last, the imaging which were collected were three-dimensional (3-D) reconstructed by using Amira 4.1 software. Results There was no obvious difference in the stain between the anterior and posterior divisions. The running of the nerve fiber bundles were dispersive from proximal end of nerve to distal end of nerve. Nerve fiber bundles of anterior division were mainly sensor nerve fiber bundles, which located in medial side. Nerve fiber bundles of posterior division were mainly moter nerve fiber bundles, having no regularity in the distribution of nerve fiber bundles. The total number of nerve fiber bundles in distal end of anterior division was 7.85 ± 1.04, the number of motor nerve fiber bundles was 2.85 ± 0.36, and the number of sensor nerve fiber bundles was 5.13 ± 1.01. The total number of nerve fiber bundles in distal end of posterior division was 9.79 ± 1.53, the number of motor nerve fiber bundles was 6.00 ± 0.69, and the number of sensor nerve fiber bundles was 3.78 ± 0.94. There were significant differences in the numbers of motor and sensor nerve fiber bundles between anterior and posterior divisions (P lt; 0.05). The microstructure 3-D model was reconstructed based on serial slice through Amira 4.1. The intercross and recombination process of nerves bundles could be observed obviously. The nerve bundle distribution showed cross and combination. Conclusion Nerve fiber bundles of anterior division are mainly sensor nerve fiber bundles and locate in medial side. Nerve fiber bundles of posterior division are mainly motor nerve fiber bundles, which has no regularity in the distribution of nerve fiber bundles. The 3-D reconstruction can display the internal structure feature of the C7 division end.
Objective To study the hemodynamic characteristics of concealed perforator flap in mini-pigs by ultrasonic Doppler technique. Methods Seven 7-month-old mini-pigs, weighing 20-25 kg, were included in the study. The saphenous artery perforator flap (group A, n=4), saphenous artery concealed perforator flap (group B, n=5), and saphenous artery concealed perforator flap combined with sarcolemma (group C, n=5) models were established randomly on both hind limbs of pigs. The pigs and flap survival conditions were observed after operation. The percentage of flap survival area was calculated by Photoshop CS5 software at 5 days after operation. Ultrasonic Doppler technique was performed on the flaps before operation and at immediate, 3 days, and 5 days after operation to record the hemodynamic changes of the flaps. The hemodynamic indicators of saphenous artery (inner diameter, peak systoli velocity, resistance index, and blood flow) and saphenous vein (inner diameter, maximum velocity, and blood flow) were recorded. Results At 1 day after operation, 1 pig died of infection, and the rest survived until the experiment was completed. Finally, the 3 flaps of group A, 4 of group B, and 5 of group C were included in the study. The flaps of the 3 groups all showed swelling after operation, which was most significant at 3 days. At 3 days after operation, the flaps in group B showed partial bruising and necrosis. At 5 days after operation, the flaps in groups A and C were basically alive, and the necrosis area of flap in group B increased further. The percentage of flap survival area in groups A, B, and C were 99.7%±0.5%, 74.8%±26.4%, and 100%, respectively. The percentage of flap was significantly lower in group B than in groups A and C (P<0.05). There was no significant difference between groups A and C (P>0.05). There were significant differences in the hemodynamic indicators of saphenous artery and vein between different time points in 3 groups (P<0.05). There was no significant difference in each indicator between groups at each time point (P>0.05). Conclusion Both the saphenous artery concealed perforator flap and the flap combined with sarcolemma have stable blood flow, but the survival area of the latter was better than the former.
【Abstract】 Objective To report cl inical experience in the use of temporary intravascular shunts (TIVS) for quickrestoration of perfusion to the extremity with major vascular injury. Methods Between August 2009 and March 2011, TIVSwas applied temporarily to restore blood perfusion to the extremity in 6 patients with major extremity vascular structure injury secondary to trauma (4 patients) or tumor resection (2 patients), who would received vascular transplantation and underwent long ischemia. The patterns of vascular shunts included external carotid artery-subclavian artery, axillary artery-axillary artery, axillary vein-subclavian vein, brachial artery-brachial artery, brachial vein-brachial vein, brachial artery-radial artery, femoral artery-popliteal artery, and popliteal artery-posterior tibial artery. After TIVS, extensive debridement, fracture fixation, or tumor excision was performed. Then the shunted tubes were removed, and the vessels were repaired definitly. Six vessels were repaired by transplanting the great saphenous veins; one vessel was anastomosed directly without tension; and one vessel was repaired by artificial vascular graft. Results All shunted tubes were successfully established within 5 to 10 minutes (mean, 8.2 minutes). The duration of bypass ranged from 67 to 210 minutes. After establishment of TIVS, blood perfusion to the affected limb was improved. When shunted tubes were removed, thrombosis and partial obstruction occurred in one who accepted amputation, and the others kept patency. No loosening of tubes and haemorrhage occurred. At 2-15 months of follow-up, affected limbs had good blood supply. Conclusion TIVS is rapid and simple, which can quickly restore blood perfusion to the extremity with major vascular injury and shorten the ischemic time of the affected extremity.