Rapid prototyping drill guide template for lumbar pedicle screw placement / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To develop a novel method of spinal pedical stereotaxy by reverse engineering and rapid prototyping techniques, and to validate its accuracy by experimental and clinical studies.</p><p><b>METHODS</b>A 3D reconstruction model for the desired lumbar vertebra was generated by using the Mimics 10.11 software, and the optimal screw size and orientation were determined using the reverse engineering software. Afterwards, a drill template was created by reverse engineering principle, whose surface was the antitemplate of the vertebral surface. The drill template and its corresponding vertebra were manufactured using the rapid prototyping technique.</p><p><b>RESULTS</b>The accuracy of the drill template was confirmed by drilling screw trajectory into the vertebral biomodel preoperatively. This method also showed its ability to customize the placement and size of each screw based on the unique morphology of the lumbar vertebra.The drill template fits the postural surface of the vertebra very well in the cadaver experiment. Postoperative CT scans for controlling the pedicle bore showed that the personalized template had a high precision in cadaver experiment and clinical application. No misplacement occurred by using the personalized template. During surgery, no additional computer assistance was needed.</p><p><b>CONCLUSIONS</b>The authors have developed a novel drill template for lumbar pedicle screw placement with good applicability and high accuracy. The potential use of drill templates to place lumbar pedicle screws is promising. Our methodology appears to provide an accurate technique and trajectory for pedicle screw placement in the lumbar spine.</p>

Application of navigation template to fixation of sacral fracture using three-dimensional reconstruction and reverse engineering technique / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To provide a new method in the fixation of sacral fracture by means of three-dimensional reconstruction and reverse engineering technique.</p><p><b>METHODS</b>Pelvis image data were obtained from three-dimensional CT scan in patients with sacral fracture. The data were transferred into a computer workstation. The three-dimensional models of pelvis were reconstructed using Amira 3.1 software and saved in STL format. Then the three-dimensional fracture models were imported into Imageware 9.0 software. Different situations of reduction (total reduction, half reduction and non-reduction) were simulated using Imageware 9.0 software. The best direction and location of extract iliosacral lag screws were defined using reverse engineering according to these three situations and navigation templates were designed according to the anatomic features of the postero-iliac part and the channel. The exact navigational template was made by rapid prototyping. Drill guides were sterilized and used intraoperatively to assist in surgical navigation and the placement of iliosacral lag screws.</p><p><b>RESULTS</b>Accurate screw placement was confirmed with postoperative X-ray and CT scanning. The navigation template was found to be highly accurate.</p><p><b>CONCLUSION</b>The navigation template may be a useful method in minimal-invasive fixation of sacroiliac joint fracture.</p>

Three-dimensional reconstruction technique in gastrocnemius flap surgery: initial clinical application / 南方医科大学学报

<p><b>OBJECTIVE</b>To discuss the experience with three-dimensional reconstruction technique in initial clinical application in gastrocnemius muscle flap surgery.</p><p><b>METHOD</b>From 2007 to 2008, 7 patients received gastrocnemius muscle flap surgeries to repair the wounds. Preoperative CT angiography or magnetic resonance imaging (MRI) was performed after injection of the contrast media for individualized three-dimensional gastrocnemius muscle flap reconstruction using Amira4.1 software. According to the size of the defect in the wound, individualized three-dimensional gastrocnemius muscle flap was designed and harvested from the posterior leg.</p><p><b>RESULTS</b>Individualized three-dimensional reconstruction of the gastrocnemius flap was performed in 7 cases, and the reconstructed flaps clearly displayed the blood vessels, skin and the adjacent three-dimensional structures. In 6 cases the main perforating branched and trunk of the blood vessels in the designed flap were consistent with the surgical findings; in 1 case, the perforating branches failed to be clearly displayed in the designed flap, and surgical examination identified perforating branches with an average diameter of 0.5 mm (minimally 0.3 mm). The flaps survived in all the 7 cases.</p><p><b>CONCLUSIONS</b>Three-dimensional reconstruction of the gastrocnemius flap based on the lower limb CT angiography or MRI allows three-dimensional observation of the anatomy of the flap and accurate marking of the extent of the flap to be harvested, therefore avoiding intraoperative injuries to the blood vessels to better survival of the flaps.</p>

Primary clinical result of digital template as navigation to supper cervical pedicle instrumentation / 中华外科杂志

<p><b>OBJECTIVE</b>To observe the primary clinical result of digital template as navigation to the upper cervical pedicle instrumentation.</p><p><b>METHODS</b>CT scan of upper cervical vertebrae was performed. 3-D model of upper cervical vertebrae was reconstructed by software Amira 3.1 and was preserved in STL format. Then 3-D model was run in software UG Imageware 12.0, the best pedicle channel was extracted according to the reverse engineering principle. A virtual navigational template was established according to he lamina anatomic trait, and the best pedicle channel. The virtual vertebrae and navigational template were manufactured using rapid prototyping. The navigational template was sterilized and used intra operative to assist with the placement of pedicle screw. The Accuracy of screw placement was confirmed with postoperative X-ray and CT scanning.</p><p><b>RESULTS</b>The digital navigational template had been established and used in the 3 cases, the good trajectory of cervical pedicle had been showed by the CT scan of post operation. There were not complications of related pedicle screw insertion.</p><p><b>CONCLUSIONS</b>A novel method of upper cervical pedicle location using Reverse Engineering and rapid prototyping has been developed; the navigational template is found to be highly accuracy and has great expectation.</p>

Design and preliminary clinical application of a new digitalized navigation template for fixation of the inferior tibiofibular joint / 南方医科大学学报

<p><b>OBJECTIVE</b>To design and prepare a new digitalized navigation template for fixation of inferior tibiofibular joint using three-dimensional reconstruction and reverse engineering techniques.</p><p><b>METHODS</b>Five patients with inferior tibiofibular joint rupture without fibula fracture underwent three-dimensional CT scanning of the lower limbs. The image data were transferred into Mimics software, and after reconstruction of the three-dimensional models of inferior tibiofibular joint rupture and saving in .stl format, the three-dimensional models were imported into Imageware10.0 software to determine the three-dimensional plane of reference. The location of the optimal pedicle channel was defined using reverse engineering and AO internal fixation principle. The template was designed according to the anatomic features of the fibular surface, and the optimal pedicle channel and the template were overlapped as the navigational template, which was manufactured by rapid prototyping. The inferior tibiofibular joint was reduced and the template was placed distally on the external fibula, and the location for screw insertion was defined by the navigation template.</p><p><b>RESULTS AND CONCLUSION</b>The digitalized model of the inferior tibiofibular joint was established. The navigation template manufactured offered good compatibility and was applied successfully for fixation of the inferior tibiofibular joint. This approach provides a new means for fixation of ruptured inferior tibiofibular joint using the reverse engineering and digitized 3-dimensional reconstruction techniques.</p>

Dynamic variation of HIV-1 CRF07_BC env gene in early HIV-1 infection / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To understand the evolution of HIV-1 CRF07_BC envelope, we performed a longitudinal study on two patients during their early HIV-1 infection.</p><p><b>METHODS</b>RNA was extracted from the plasma of the individuals and the C2-C5 fragments of the gp120 gene of HIV-1 were amplified by RT-PCR. Purified DNA segments were inserted into T easy vector and transformed into E. coli Top 10 competent cells. Positive clones were identified by blue-white screening, confirmed by PCR and sequenced by ABI 3700.</p><p><b>RESULTS</b>The samples were collected from the patients every 6 months from seroconversion time. The genetic diversity and divergence in env gene showed consistent increases over time. Our sequence analysis also revealed obvious non-synonymous change in env C1, C3 and V4 regions among these samples.</p><p><b>CONCLUSION</b>The results support the concept that the consistent pattern of viral evolution existed during early phase of HIV-1 infection. C1, C3 and V4 region of env gene may be mainly immunological target during AIDS progression.</p>

Landmark-based automatic registration of serial cross-sectional images of Chinese digital human using Photoshop and Matlab software / 南方医科大学学报

This paper describes automatic registration of the serial cross-sectional images of Chinese digital human by projective registration method based on the landmarks using the commercially available software Photoshop and Matlab. During cadaver embedment for acquisition of the Chinese digital human images, 4 rods were placed parallel to the vertical axis of the frozen cadaver to allow orientation. Projective distortion of the rod positions on the cross-sectional images was inevitable due to even slight changes of the relative position of the camera. The original cross-sectional images were first processed using Photoshop software firstly to obtain the images of the orientation rods, and the centroid coordinate of every rod image was acquired with Matlab software. With the average coordinate value of the rods as the fiducial point, two-dimensional projective transformation coefficient of each image was determined. Projective transformation was then carried out and projective distortion from each original serial image was eliminated. The rectified cross-sectional images were again processed using Photoshop to obtain the image of the first orientation rod, the coordinate value of first rod image was calculated using Matlab software, and the cross-sectional images were cut into images of the same size according to the first rod spatial coordinate, to achieve automatic registration of the serial cross-sectional images. sing Photoshop and Matlab softwares, projective transformation can accurately accomplish the image registration for the serial images with simpler calculation processes and easier computer processing.

Observation of the sectional anatomic structure and visualization of the normal lumbar plexus of virtual Chinese human / 中华外科杂志

<p><b>OBJECTIVE</b>To observe the normal structure of lumbar plexus in the virtual Chinese Human (VCH) Female I and Male III and establish a digitized visible model of their lumbar plexus.</p><p><b>METHODS</b>The cross-sectional images from the VCH Female I and Male III dataset were reviewed to study lumbar plexus structures on a section-by-section basis. The nerve roots, major psoas muscle and blood vessels were also observed. Three-dimensional computerized reconstructions of lumbar plexus and its adjacent structures were conducted from these data using Amira 3.1 (TGS) imaging software respectively.</p><p><b>RESULTS</b>The three-dimensional reconstructed visible models perfectly displayed the anatomic relationships of lumbar plexus structures and their adjacent structures.</p><p><b>CONCLUSIONS</b>VCH Female I and Male III dataset can provide complete and accurate data of main structure of lumbar plexus. The digitized models of lumbar plexus offer unique insights into the complex anatomy, and morphologic data for imaging diagnosis and treatment of the injury of lumbar plexus.</p>

Vascular 3D visualization and flap design on the each perforator of anterolateral thigh flap / 中华显微外科杂志

Objective To provide the skin vessels morphologie basis for perforating flap of the antero- lateral thigh(ALT).Methods Six sides lower limbs of adult fresh cadaver specimens perfused with lead oxide-gelatine mixture were used.Observe the peraforators of anterolateral thigh by dissection.The elevated tissue was radiographed by X-ray and MSCT-scanning.Computer techniques was used for the detection and 3D-reconstruction of the regions of each perforators of ALT flap.Results The three-dimensional recostruct- ed digitized visible models perfectly displayed the anatomic structures of arteries on the anterolateral thigh, and,the morphology and distribution of the vascular territory of each perforator from descending branch of LCFA was displayed in the images of 3D-visualization,their effective morphology and distribution were same, and they accord with vascular territory of radiograph.On the 2D-image of X-ray,The margins of the anatomical distribution of each perforator from descending branch of the lateral circumflex femoral artery were determined, their total areas was about 25cm?24cm.Conclusion Since the digitized image of perforator territory can accord with the morphology of anatomy,and can off vascular structure insights into cutaneous perforator anato- my,their 3D visualizative models can be applied in pre-operative designing and virtual operation procedures, and can be helped for study of perforator flap.

Identification of HIV-1 specific T lymphocyte responses in highly exposed persistently seronegative Chinese / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Studies of highly exposed persistently seronegative (HEPS) individuals may provide valuable information on mechanisms of protection and on vaccine design. Cellular immune responses play a critical role in containing human immunodeficiency virus. However, the cellular immune responses in HEPS individuals have not been thoroughly assessed at the entire viral genome level.</p><p><b>METHODS</b>Ten HEPS Chinese with a history of frequent penetrative vaginal intercourse (mean frequency, at least once a week), with some unprotected sexual contact occurring in the weeks or days immediately before enrollment, 25 HIV-1 seropositive individuals, 10 HIV-1-seronegative healthy individuals with low-risk sexual behavior and no history suggestive of exposure to HIV-1 infection were enrolled. HIV-1-specific T cell responses were comprehensively analyzed by an interferon-gamma Elispot assay against 770 overlapping peptides spanning all HIV-1 proteins.</p><p><b>RESULTS</b>HIV-1-specific T-cell responses of interferon-gamma secretion were identified in 3 (30%) out of 10 HEPS individuals; the specific cytotoxic T lymphocytes were targeted at Pol (2/10), Env (2/10), and Tat (1/10). HIV-1-specific T-cell responses of interferon-gamma secretion were identified in 20 (80%) out of 25 seropositive intravenous drug users (IDUs), revealing that all HIV-1 proteins and protein subunits could serve as targets for HIV-1-specific CD8(+) T cell responses with 85% recognizing Gag, 80% recognizing Nef, 75% recognizing Pol, 60% recognizing Env, 55% recognizing Vpu, 45% recognizing Vpr, 20% recognizing Vif, 20% recognizing Tat and 15% recognizing Rev in these seropositive individuals. None of the seronegative healthy individuals gave the positive T-cell responses.</p><p><b>CONCLUSIONS</b>About 30% of HEPS Chinese mounted HIV-1 specific T cell immune responses. Cell-mediated immunity against HIV-1 may be developed through non-productive infections.</p>

HLA-B Alleles Associated with Susceptibility or Resistance to Human Immunodeficiency Virus Type 1 in a Xinjiang Uygur Population, China / 中国病毒学

Host genetic factors, such as human leukocyte antigen (HLA) alleles, are important in Human immunod-eficiency virus (HIV) infection and its progression to AIDS. HLA class I genes, especially highly polymorphicHLA-B genes, are involved in the activation of HLA-restricted cytotoxic T lymphocytes (CTLs) against HIV, andthus control susceptibility to or protect against this virus. The present study was aimed to determine the distributionof HLA-B alleles in the Chinese Uygur ethnic group and its association with HIV infection. One hundred ten healthycontrol (HIV negative) and 128 HIV positive Chinese Xinjiang Uygur ethnic individuals were used in this study.HLA typing for B allele was performed by polymerase chain reaction (PCR) with sequence-specific primers (SSP).Hardy-Weinberg equilibrium was calculated using POPGENE software for the healthy control group. The HLA-Bfrequency of each allele was compared between the patients and the controls using the chi-square test. In HIV-1-pos-itive group, gene frequency of allele B * 4901 was significantly higher compared to the healthy control subjects (P=0.02, OR=3.06, 95%CI=1.16～8.10 forB*4901). In contrast, the gene frequency of B * 40 in healthy controlswas significantly higher than in the HIV-positive patients (P=0.02, OR=0.39, 95%CI=0.07～0. 92 for B* 40).In this study, HLA allele B * 4901 may be associated with increased susceptibility to HIV-1 infection, whereas the B* 40 allele may be associated with resistance to H HIV-1 infection.

Application of digitalization and virtual reality in transplantation with anterolateral thigh flap / 中华创伤骨科杂志

Objective To observe the normal structures of arteria circumflexa femoris lateralis (ACFL) and to establish digitized visible models of anterolateral thigh(ALT) flap,which can be used in clinical training and operation design.Methods The cross-sectional images from the VCH Male 3 dataset were reviewed to study ACFL structures on a section-by-section basis.Next,one adult fresh cadaver specimen was perfused with lead ox- ide-gelatine mixture to be subject to radiographic CT scanning on its lower limbs.Likewise,the cross-sectional images from the CT images were reviewed to study ACFL structures on a section-by-section basis.Three-dimensional computerized reconstructions of ACFL structures and their adjacent struetures were conducted from the two sets of data using Amira 3.1 (TGS) software respectively.Results The three-dimensional reconstructed visible models established by the above two methods perfectly displayed the anatomic relationships of ACFL structures and their adjacent structures.Conclusions Since the digitized images of ACFL structures can offer section by section in- sights into the ACFL anatomy,their 3D reconstructive models ean be applied in clinical training,pre-operative designing and virtual operation procedures.