Multitask deep learning for prediction of microvascular invasion and recurrence-free survival in hepatocellular carcinoma based on MRI images.

BACKGROUND AND AIMS: Accurate preoperative prediction of microvascular invasion (MVI) and recurrence-free survival (RFS) is vital for personalised hepatocellular carcinoma (HCC) management. We developed a multitask deep learning model to predict MVI and RFS using preoperative MRI scans. METHODS: Utilising a retrospective dataset of 725 HCC patients from seven institutions, we developed and validated a multitask deep learning model focused on predicting MVI and RFS. The model employs a transformer architecture to extract critical features from preoperative MRI scans. It was trained on a set of 234 patients and internally validated on a set of 58 patients. External validation was performed using three independent sets (n = 212, 111, 110). RESULTS: The multitask deep learning model yielded high MVI prediction accuracy, with AUC values of 0.918 for the training set and 0.800 for the internal test set. In external test sets, AUC values were 0.837, 0.815 and 0.800. Radiologists' sensitivity and inter-rater agreement for MVI prediction improved significantly when integrated with the model. For RFS, the model achieved C-index values of 0.763 in the training set and ranged between 0.628 and 0.728 in external test sets. Notably, PA-TACE improved RFS only in patients predicted to have high MVI risk and low survival scores (p < .001). CONCLUSIONS: Our deep learning model allows accurate MVI and survival prediction in HCC patients. Prospective studies are warranted to assess the clinical utility of this model in guiding personalised treatment in conjunction with clinical criteria.

In-Depth Quantification of Cell Division and Elongation Dynamics at the Tip of Growing Arabidopsis Roots Using 4D Microscopy, AI-Assisted Image Processing and Data Sonification.

One of the fundamental questions in plant developmental biology is how cell proliferation and cell expansion coordinately determine organ growth and morphology. An amenable system to address this question is the Arabidopsis root tip, where cell proliferation and elongation occur in spatially separated domains, and cell morphologies can easily be observed using a confocal microscope. While past studies revealed numerous elements of root growth regulation including gene regulatory networks, hormone transport and signaling, cell mechanics and environmental perception, how cells divide and elongate under possible constraints from cell lineages and neighboring cell files has not been analyzed quantitatively. This is mainly due to the technical difficulties in capturing cell division and elongation dynamics at the tip of growing roots, as well as an extremely labor-intensive task of tracing the lineages of frequently dividing cells. Here, we developed a motion-tracking confocal microscope and an Artificial Intelligence (AI)-assisted image-processing pipeline that enables semi-automated quantification of cell division and elongation dynamics at the tip of vertically growing Arabidopsis roots. We also implemented a data sonification tool that facilitates human recognition of cell division synchrony. Using these tools, we revealed previously unnoted lineage-constrained dynamics of cell division and elongation, and their contribution to the root zonation boundaries.

Mergeomics 2.0: a web server for multi-omics data integration to elucidate disease networks and predict therapeutics.

The Mergeomics web server is a flexible online tool for multi-omics data integration to derive biological pathways, networks, and key drivers important to disease pathogenesis and is based on the open source Mergeomics R package. The web server takes summary statistics of multi-omics disease association studies (GWAS, EWAS, TWAS, PWAS, etc.) as input and features four functions: Marker Dependency Filtering (MDF) to correct for known dependency between omics markers, Marker Set Enrichment Analysis (MSEA) to detect disease relevant biological processes, Meta-MSEA to examine the consistency of biological processes informed by various omics datasets, and Key Driver Analysis (KDA) to identify essential regulators of disease-associated pathways and networks. The web server has been extensively updated and streamlined in version 2.0 including an overhauled user interface, improved tutorials and results interpretation for each analytical step, inclusion of numerous disease GWAS, functional genomics datasets, and molecular networks to allow for comprehensive omics integrations, increased functionality to decrease user workload, and increased flexibility to cater to user-specific needs. Finally, we have incorporated our newly developed drug repositioning pipeline PharmOmics for prediction of potential drugs targeting disease processes that were identified by Mergeomics. Mergeomics is freely accessible at http://mergeomics.research.idre.ucla.edu and does not require login.

Simple and Rapid Synthesis of Branched Peptides through Microwave-Assisted On-Bead Ligation.

A rapid on-bead convergent method for preparing branched peptides was reported. Linear peptides were prepared on Dbz resin and ligated various branched cores, including lysine dendrons and other dendritic compounds. Alongside microwave irradiation, <1.5 equiv of peptides is sufficient to afford 50-65% yields of pure branched peptides without chromatographic purification. Remarkably, the desired compounds were prepared within hours.

Comparative effects of EMG-driven robot-assisted therapy versus task-oriented training on motor and daily function in patients with stroke: a randomized cross-over trial.

BACKGROUND: Robot-assisted hand training has shown positive effects on promoting neuromuscular control. Since both robot-assisted therapy and task-oriented training are often used in post-stroke rehabilitation, we raised the question of whether two interventions engender differential effects in different domains. METHODS: The study was conducted using a randomized, two-period crossover design. Twenty-four chronic stroke survivors received a 12-session robot-assisted intervention followed by a 12-session task-oriented intervention or vice versa. A 1-month washout period between each intervention was implemented. Outcome measures were evaluated before the intervention, after the first 12-session intervention, and after the second 12-session intervention. Clinical assessments included Fugl-Meyer Assessment for Upper Extremity, Wolf Motor Function Test, Action Research Arm Test and Motor Activity Log. RESULTS: Our findings suggested that EMG-driven robot-assisted therapy was as effective as task-oriented training in terms of improving upper limbs functional performance in activity domain, and robot-assisted therapy was more effective in improving movement duration during functional tasks. Task-oriented training showed better improvement in body function domain and activity and participation domain, especially in improving spontaneous use of affected arm during daily activities. CONCLUSIONS: Both intervention protocol had their own advantages in different domains, and robot-assisted therapy may save manpower and be considered as an alternative intervention to task-oriented training. Combining the two approaches could yield results greater than either alone, which awaits further study. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03624153. Registered on 9th August 2018, https://clinicaltrials.gov/ct2/show/NCT03624153 .

Zfra Inhibits the TRAPPC6AΔ-Initiated Pathway of Neurodegeneration.

When WWOX is downregulated in middle age, aggregation of a protein cascade, including TRAPPC6AΔ (TPC6AΔ), TIAF1, and SH3GLB2, may start to occur, and the event lasts more than 30 years, which results in amyloid precursor protein (APP) degradation, amyloid beta (Aß) generation, and neurodegeneration, as shown in Alzheimer's disease (AD). Here, by treating neuroblastoma SK-N-SH cells with neurotoxin MPP+, upregulation and aggregation of TPC6AΔ, along with aggregation of TIAF1, SH3GLB2, Aß, and tau, occurred. MPP+ is an inducer of Parkinson's disease (PD), suggesting that TPC6AΔ is a common initiator for AD and PD pathogenesis. Zfra, a 31-amino-acid zinc finger-like WWOX-binding protein, is known to restore memory deficits in 9-month-old triple-transgenic (3xTg) mice by blocking the aggregation of TPC6AΔ, SH3GLB2, tau, and amyloid ß, as well as inflammatory NF-κB activation. The Zfra4-10 peptide exerted a strong potency in preventing memory loss during the aging of 3-month-old 3xTg mice up to 9 months, as determined by a novel object recognition task (ORT) and Morris water maize analysis. Compared to age-matched wild type mice, 11-month-old Wwox heterozygous mice exhibited memory loss, and this correlates with pT12-WWOX aggregation in the cortex. Together, aggregation of pT12-WWOX may link to TPC6AΔ aggregation for AD progression, with TPC6AΔ aggregation being a common initiator for AD and PD progression.

Accurate and fast mitotic detection using an anchor-free method based on full-scale connection with recurrent deep layer aggregation in 4D microscopy images.

BACKGROUND: To effectively detect and investigate various cell-related diseases, it is essential to understand cell behaviour. The ability to detection mitotic cells is a fundamental step in diagnosing cell-related diseases. Convolutional neural networks (CNNs) have been successfully applied to object detection tasks, however, when applied to mitotic cell detection, most existing methods generate high false-positive rates due to the complex characteristics that differentiate normal cells from mitotic cells. Cell size and orientation variations in each stage make detecting mitotic cells difficult in 2D approaches. Therefore, effective extraction of the spatial and temporal features from mitotic data is an important and challenging task. The computational time required for detection is another major concern for mitotic detection in 4D microscopic images. RESULTS: In this paper, we propose a backbone feature extraction network named full scale connected recurrent deep layer aggregation (RDLA++) for anchor-free mitotic detection. We utilize a 2.5D method that includes 3D spatial information extracted from several 2D images from neighbouring slices that form a multi-stream input. CONCLUSIONS: Our proposed technique addresses the scale variation problem and can efficiently extract spatial and temporal features from 4D microscopic images, resulting in improved detection accuracy and reduced computation time compared with those of other state-of-the-art methods.

Estimation of the Number of Passengers in a Bus Using Deep Learning.

For the development of intelligent transportation systems, if real-time information on the number of people on buses can be obtained, it will not only help transport operators to schedule buses but also improve the convenience for passengers to schedule their travel times accordingly. This study proposes a method for estimating the number of passengers on a bus. The method is based on deep learning to estimate passenger occupancy in different scenarios. Two deep learning methods are used to accomplish this: the first is a convolutional autoencoder, mainly used to extract features from crowds of passengers and to determine the number of people in a crowd; the second is the you only look once version 3 architecture, mainly for detecting the area in which head features are clearer on a bus. The results obtained by the two methods are summed to calculate the current passenger occupancy rate of the bus. To demonstrate the algorithmic performance, experiments for estimating the number of passengers at different bus times and bus stops were performed. The results indicate that the proposed system performs better than some existing methods.

Accuracy of CAD/CAM Digital Impressions with Different Intraoral Scanner Parameters.

The advancement of intraoral scanners has allowed for more efficient workflow in the dental clinical setting. However, limited data exist regarding the accuracy of the digital impressions produced with various scanner settings and scanning approaches. The purpose of this in vitro study was to compare the accuracy of digital impressions at the crown preparation margin using different scanning resolutions of a specific intraoral scanner system. An all-ceramic crown preparation of a mandibular first molar was constructed in a typodont, and a scan (n = 3) was created with an industrial-grade laboratory scanner (3Shape D2000) as the control. Digital impressions were obtained with an intraoral scanner (3Shape TRIOS 3) under three settings-high resolution (HR), standard resolution (SR), and combined resolution (SHR). Comparative 3D analysis of scans was performed with Geomagic Control X software to measure the discrepancy between intraoral scans and the control scan along the preparation finish line. The scan time and number of images captured per scan were recorded. Statistical analysis was performed by one-way ANOVA, two-way repeated measures ANOVA, Pearson's correlation, and Dunnett's T3 test (α = 0.05). Significant differences were observed for scan time and for number of images captured among scan resolution settings (α < 0.05). The scan time for the SR group was, on average, 34.2 s less than the SHR group and 46.5 s less than the HR group. For discrepancy on the finish line, no significant differences were observed among scanning resolutions (HR: 31.5 ± 5.5 µm, SHR: 33.2 ± 3.7 µm, SR: 33.6 ± 3.1 µm). Significant differences in discrepancy were observed among tooth surfaces, with the distal surface showing the highest discrepancies. In conclusion, the resolution of the intra-oral scanner is primarily defined by the system hardware and optimized for default scans. A software high-resolution mode that obtains more data over a longer time may not necessarily benefit the scan accuracy, while the tooth preparation and surface parameters do affect the accuracy.

Transposition of Duplicated Thumb for Reconstruction of Asymmetric Radial Polydactyly.

BACKGROUND: In this study, we present the long-term functional and aesthetic outcomes in patients with complicated asymmetric radial polydactyly treated with this surgical technique involving the transposition of a duplicated thumb. METHODS: We evaluated 6 thumbs in 6 patients who underwent radial polydactyly reconstruction using the transposition of duplicated thumb procedure between 2001 and 2017. The procedure was used when one of the thumbs was not obviously dominant over the other, with one having a better proximal portion and the other having a better distal portion. The average age at the time of surgery was 35 months, and at the final follow-up, average age was 86.5 months. Objective outcome values were obtained, and the Japanese Society for Surgery of the Hand evaluation form was adopted to assess functional and cosmetic outcomes. RESULTS: Neither soft tissue loss nor nonunion of the osteotomy was noted. No patients reported pain or difficulties in their activities. Mean flexion-extension arc for the metacarpophalangeal joint was 72.9° (range, 8.8° extension to 64.1° flexion), and that for the interphalangeal joint was 44.0° (range, 5.7° extension to 38.3° flexion). Mean key pinch, tip pinch, and grip strength of unaffected thumb were 75.1%, 68.7%, and 81.9%, respectively. Total scores using the Japanese Society for Surgery of the Hand scoring system averaged 18.2 points, and the results were excellent in 1 case and good in 5. CONCLUSIONS: Transposition of duplicated thumb can provide durable functional and cosmetic results for Rotterdam types IV and VI with asymmetric radial polydactyly in which neither thumb has adequate distal and proximal components.

Robot-assisted microvascular anastomosis in head and neck free flap reconstruction: Preliminary experiences and results.

BACKGROUND: The da Vinci Surgical System has facilitated considerable advancements in surgery. The process and results of robot-assisted microvascular anastomosis in real clinical situations have rarely been reported. This study presents our experience of performing robot-assisted microvascular anastomosis in free flap reconstruction in patients with oropharyngeal cancer. PATIENTS AND METHODS: This was a retrospective study of reconstructive operations using a free radial forearm flap for oropharyngeal defects after tumor extirpation in 15 consecutive adult patients (12 men and 3 women). In total, 17 robot-assisted microvascular vessel anastomoses (2 arteries and 15 veins) were performed; moreover, 13 arteries and 13 veins were anastomosed using the standard operating microscope and hand-sewing technique. RESULTS: The recipient and donor vessel diameters were 2.5 ± 0.7 and 2.1 ± 0.8 mm, respectively. The donor blood vessel diameter selected for anastomosis using da Vinci Surgical System was significantly smaller (2.1 ± 0.8 vs. 2.5 ± 0.6 mm) than that for a standard operating microscope and hand-sewing technique (p = .021), the operating time spent (38.4 ± 10.4 vs. 28.0 ± 7.7 min) was significantly longer (p < .001). The vascular patency rate was 100%, and all flaps survived without requiring additional operation for revision. CONCLUSION: Robotic surgical systems can facilitate vascular microanastomosis and provide a blood vessel patency rate comparable to that of a standard operating microscope and hand-sewing technique.

Spectral Representation vis Data-Guided Sparsity for Hyperspectral Image Super-Resolution†.

Hyperspectral imaging is capable of acquiring the rich spectral information of scenes and has great potential for understanding the characteristics of different materials in many applications ranging from remote sensing to medical imaging. However, due to hardware limitations, the existed hyper-/multi-spectral imaging devices usually cannot obtain high spatial resolution. This study aims to generate a high resolution hyperspectral image according to the available low resolution hyperspectral and high resolution RGB images. We propose a novel hyperspectral image superresolution method via non-negative sparse representation of reflectance spectra with a data guided sparsity constraint. The proposed method firstly learns the hyperspectral dictionary from the low resolution hyperspectral image and then transforms it into the RGB one with the camera response function, which is decided by the physical property of the RGB imaging camera. Given the RGB vector and the RGB dictionary, the sparse representation of each pixel in the high resolution image is calculated with the guidance of a sparsity map, which measures pixel material purity. The sparsity map is generated by analyzing the local content similarity of a focused pixel in the available high resolution RGB image and quantifying the spectral mixing degree motivated by the fact that the pixel spectrum of a pure material should have sparse representation of the spectral dictionary. Since the proposed method adaptively adjusts the sparsity in the spectral representation based on the local content of the available high resolution RGB image, it can produce more robust spectral representation for recovering the target high resolution hyperspectral image. Comprehensive experiments on two public hyperspectral datasets and three real remote sensing images validate that the proposed method achieves promising performances compared to the existing state-of-the-art methods.

Fracture resistance of cingulum rest seats in CAD-CAM tooth-colored crowns for removable partial denture abutments.

STATEMENT OF PROBLEM: The prevalent use of computer-aided design and computer-aided manufacturing (CAD-CAM) for tooth-colored ceramic materials has led to several case reports and retrospective clinical studies of surveyed crowns used to support removable partial dentures. How the specific contour of a cingulum rest seat affects the fracture resistance of these CAD-CAM tooth-colored materials is unknown. PURPOSE: The purpose of this in vitro study was to compare the fracture resistance of monolithic CAD-CAM tooth-colored mandibular canine-surveyed ceramic crowns with cingulum rest seats of different designs. MATERIAL AND METHODS: Five groups (n=24/group) of CAD-CAM tooth-colored crowns were milled from the same standard tessellation language (STL) file: group EM, lithium disilicate-based material (IPS e.max CAD CEREC blocks); group SM, zirconia-based material (NexxZr T); group LP, zirconia-based material (Lava Plus High Translucency); group ZC, zirconia-based material (ZirCAD LT); and group MZ, composite resin (MZ100 CEREC blocks), used as a control. Crowns from each group were divided into 2 subgroups representing 2 shapes of cingulum rest seat design: round design subgroup (n=12) with 0.5-mm radius of curvature and sharp design subgroup (n=12) with 0.25-mm radius of curvature for the rest seat preparation. The crowns were cemented with resin cement to a composite resin die on a steel nut. After 24 hours of storage in water at 37°C, the specimens were statically loaded to fracture with a custom metal retainer on top of the cingulum rest seat by using a universal testing machine at a crosshead speed of 1.5 mm/min. Two-way ANOVA and the Tukey honestly significant difference tests were used to control the familywise error rate (α=.05). Representative specimens were examined using an optical stereomicroscope at ×10 magnification and a scanning electron microscope to determine the failure patterns and fracture mechanism. RESULTS: The results of the ANOVA test indicated statistically significant differences by materials and rest seat designs (P<.001). The mean ±standard deviation maximal load capacity was 773.5 ±255.0 N for group MZ, 1124.9 ±283.9 N for group EM, 2784.1 ±400.5 N for group SM, 2526.9 ±547.1 N for group LP, and 3200.8 ±416.8 N for group ZC. The round design subgroups had an approximately 30% higher mean failure load than the sharp design subgroups for all surveyed crowns. CONCLUSIONS: The present in vitro study demonstrated that zirconia-based groups fractured at twice the load as the lithium disilicate group. Of the 3 zirconia-based groups, group ZirCAD had a statistically greater fracture resistance than the other groups. Designing the cingulum rest seat to have a broad round shape provides a statistically significant higher fracture resistance than a sharp-shape design (P<.05).

Correlative Light-Electron Microscopy of Lipid-Encapsulated Fluorescent Nanodiamonds for Nanometric Localization of Cell Surface Antigens.

Containing an ensemble of nitrogen-vacancy centers in crystal matrices, fluorescent nanodiamonds (FNDs) are a new type of photostable markers that have found wide applications in light microscopy. The nanomaterial also has a dense carbon core, making it visible to electron microscopy. Here, we show that FNDs encapsulated in biotinylated lipids (bLs) are useful for subdiffraction imaging of antigens on cell surface with correlative light-electron microscopy (CLEM). The lipid encapsulation enables not only good dispersion of the particles in biological buffers but also high specific labeling of live cells. By employing the bL-encapsulated FNDs to target CD44 on HeLa cell surface through biotin-mediated immunostaining, we obtained the spatial distribution of these antigens by CLEM with a localization accuracy of ∼50 nm in routine operations. A comparative study with dual-color imaging, in which CD44 was labeled with FND and MICA/MICB was labeled with Alexa Fluor 488, demonstrated the superior performance of FNDs as fluorescent fiducial markers for CLEM of cell surface antigens.

Restoration contour is a risk indicator for peri-implantitis: A cross-sectional radiographic analysis.

AIM: The purpose of this study was to determine whether restoration emergence angle was associated with peri-implantitis. MATERIALS AND METHODS: A data set consisting of 96 patients with 225 implants (mean follow-up: 10.9 years) was utilized. Implants were divided into bone-level and tissue-level groups, and radiographs were analysed to determine the restoration emergence angles, as well as restoration profiles (convex or concave). Peri-implantitis was diagnosed based on probing depth and radiographic bone loss. Associations between peri-implantitis and emergence angles/profiles were assessed using generalized estimating equations. RESULTS: Eighty-three patients with 168 implants met inclusion criteria. The prevalence of peri-implantitis was significantly greater in the bone-level group when the emergence angle was >30 degrees compared to an angle ≤30 degrees (31.3% versus 15.1%, p = .04). In the tissue-level group, no such correlation was found. For bone-level implants, when a convex profile was combined with an angle of >30 degrees, the prevalence of peri-implantitis was 37.8% with a statistically significant interaction between emergence angle and profile (p = .003). CONCLUSIONS: Emergence angle of >30 degrees is a significant risk indicator for peri-implantitis and convex profile creates an additional risk for bone-level implants, but not for tissue-level implants.

Release of calcium ions from particulate monosodium titanates for dental mineralization applications.

PURPOSE: The calcium ion [Ca(II)] release from monosodium titanates (MST) complexed to calcium ions [Ca(II)], referred to as MST-Ca(II), was examined under varying incubation times, pH conditions, and ion equilibrium disruptions. METHODS: Sample supernatants were analyzed for Ca(II) using the QuantiChrom Calcium Assay Kit. RESULTS: No Ca(II) was detected in native MST (control) supernatants but was detected in MST-Ca(II) supernatants. At pH 7, Ca(II) release increased from 0 to 2.5 mg/dL over 3 days (P< 0.05 compared to MST control), remaining constant over the completed incubation times. At pH 5, 15 mg/dL of Ca(II) was immediately released with no further release. When the pH was modulated pH 4 to pH 9, Ca(II) concentration dropped from 25 mg/dL to ~0 mg/dL. Finally, when equilibrium was disrupted by partial replacement of the supernatant with sterile water, Ca(II) release was ongoing, reaching a cumulative total of 20 mg/dL over 35 days. CLINICAL SIGNIFICANCE: The current results suggest that particulate MST-Ca(II) complexes exhibit sustained release of calcium, and that release might be customized by conditions of pH and ionic strength. Thus, these complexes appear promising for biological applications where calcium-mediated mineralization or re-mineralization are desired.

Nanodiamonds as Nucleating Agents for Protein Crystallization.

Nanodiamond (ND) is a carbon-based nanomaterial with potential for a wide range of biological applications. One of such applications is to facilitate the nucleation of protein crystals in aqueous solution. Here, we show that NDs (nominal diameters of 30 and 100 nm) after surface oxidation in air and subsequent treatment in strong acids are useful as heterogeneous nucleating agents for protein crystallization. Tested with lysozyme, ribonuclease A, proteinase K, and catalase, the nanomaterials in either aggregate or film form are found to be able to increase the crystallization efficiency of all proteins. Particularly, for 30 nm NDs, the films with an area of ∼2 mm2 can effectively induce the crystallization of lysozyme at a concentration as low as 5 mg/mL. The efficiency can be further improved by adding preformed protein clusters (∼300 nm in diameter) as inherent nucleation precursors, as demonstrated for ribonuclease A. This combined approach is easy to implement, highly compatible with existing technologies, and can be applied to other protein samples as well.

Functional Outcomes and Complications of Robot-Assisted Free Flap Oropharyngeal Reconstruction.

BACKGROUND: Robotic surgical systems provide a clear, magnified 3-dimensional visualization as well as precise, stable instrumental movement, thereby minimizing technical difficulties that may be encountered in the surgical treatment of oropharyngeal tumors. This study assessed the outcomes of robotic-assisted free flap oropharyngeal reconstruction compared with those of conventional free flap reconstruction. MATERIALS AND METHODS: A retrospective review of 47 patients who underwent reconstructive operations using a free radial forearm fasciocutaneous flap for oropharyngeal defects was conducted over a 20-month period (May 2013-December 2014). Complications were evaluated for a robot-assisted reconstruction group and a conventional reconstruction group; postoperative complication rates and revision rates were further evaluated. The Functional Intraoral Glasgow Scale (FIGS) was adopted for functional outcome assessment. RESULTS: This study recruited 47 people who underwent reconstructive operations using a free radial forearm fasciocutaneous flap for oropharyngeal defects (14 robot-assisted and 33 conventional reconstructions). The mean postoperative FIGS score was 10.29 ± 2.02 in the robot-assisted group (P = 0.010) and 8.42 ± 2.29 in the conventional group at 1 month postoperatively. The mean postoperative FIGS score was 12.57 ± 1.91 in the robot-assisted group (P = 0.005) and 9.91 ± 3.09 in the conventional group at 3 months postoperatively. Complication rates between the robot-assisted and conventional groups were similar for flap failure (P = 0.531), partial necrosis, wound infection, hematoma or seroma formation (P = 0.893), wound dehiscence, and fistula formation (P = 0.515). The number of flap revision operations requiring additional surgery (P = 0.627) was comparable between the cohorts. CONCLUSIONS: There is no significant difference in complications or revision rates between the robot-assisted and conventional oropharyngeal reconstructions. The functional postoperative outcomes of robot-assisted reconstructions are superior to those of conventional reconstructions. Robotic surgical systems provide a safe option with optimal postoperative oral function for the free flap reconstruction of oropharyngeal defects without lip or mandible splitting.

Preoperative Computed Tomography Angiography for Evaluation of Feasibility of Free Flaps in Difficult Reconstruction of Head and Neck.

BACKGROUND: Free tissue transfer has been advocated for anatomic and functional reconstruction of soft tissue defects after surgical removal of an extensive recurrent tumor and/or arising from previous irradiation in the head and neck. We report a case series of difficult reconstruction in the head and neck in which preoperative computed tomography (CT) angiography was utilized to evaluate the feasibility of free flap reconstruction. The preoperative radiological evaluation was performed to determine the availability of reliable vessels for anastomosis in free flap reconstruction. If none was found, regional pedicle flap or palliative treatment was applied instead. The use of CT angiography allows the clinical surgeon to perform precise surgical planning with greater confidence. This may improve surgical results, thereby potentially reducing perioperative morbidity. METHODS: Twenty CT angiograms were obtained from 20 patients. All patients were men with a mean age of 57.2 years (range, 42-72 years) and were scheduled to undergo difficult reconstruction in the head and neck. All patients (20/20 [100%]) suffered from oral squamous cell carcinoma. They had all received extensive operations and radiation therapy. Eighteen patients (18/20 [90%]) had completed a course of perioperative irradiation. The CT angiography reports were used to perform detailed preoperative surgical planning accordingly. The findings of CT angiography were classified into 3 groups: group I: normal CT angiography (patent recipient arteries) (Fig. 3); group II: abnormal CT angiography (recipient vessels were present but stenosis or atherosclerotic lesions were noted) (Fig. 4); group III: abnormal CT angiography with no patent recipient arteries in bilateral sides of the neck (Fig. 5); CT angiography results were correlated to the operative findings. RESULTS: The patients were classified into 3 groups based on the angiographic findings. Six patients (6/20 [30%]) were assigned to group I, 8 patients (8/20 [40%]) to group II, and 6 patients (6/20 [30%]) to group III. In groups I and III, all patients (12/12 [100%]) underwent the treatment according to the original preoperative detailed planning. No flap failure was noted in these 2 groups. In group II, 4 patients' recipient vessels (4/8 [50%]) possessed adequate blood flow intraoperatively; hence, microvascular free flaps were transplanted. Venous congestion in 1 case (1/4 [25%]) was noted. The remaining patients in this group (4/8 [50%]) underwent reconstruction with pedicle flaps rather than free flaps because of the lack of suitable target vessels intraoperatively. All flaps (4/4 [100%]) survived. Among the patients who were treated surgically, intraoperative findings were in accordance with those predicted by CT angiography. The total abnormality rate of CT angiography was 70%. Vascular abnormalities detected as a result of preoperative CT angiography led to changes in the operative plan in 50% (10/20) of the patients. CONCLUSIONS: The use of CT angiography should be considered for difficult microsurgical reconstructions in the head and neck. When an abnormality in vascular anatomy is detected by CT angiography, the surgeon is advised to consider altering the operative plan accordingly. This allows precise operation, thereby maximizing the possibility of an optimal outcome. Changing the operative plan based on results of CT angiography may also help to avoid the difficult situation in which the surgeon finds that there are no suitable recipient vessels for free flap reconstruction during the operation. In addition, CT angiography enables surgeons to conduct the preoperative surgical planning with greater confidence, thereby potentially enhancing the success rate of difficult reconstructions in the head and neck, which in turn would tend to improve the perioperative course for the patient and consequently to improve results by decreasing vascular complication rates.

Essential calcium-binding cluster of Leptospira LipL32 protein for inflammatory responses through the Toll-like receptor 2 pathway.

Leptospirosis is the most widespread zoonosis caused by the pathogenic Leptospira worldwide. LipL32, a 32-kDa lipoprotein, is the most abundant protein on the outer membrane of Leptospira and has an atypical poly(Asp) motif ((161)DDDDDGDD(168)). The x-ray crystallographic structure of LipL32 revealed that the calcium-binding cluster of LipL32 includes several essential residues Asp(132), Thr(133), Asp(164), Asp(165), and Tyr(178). The goals of this study were to determine possible roles of the Ca(2+)-binding cluster for the interaction of LipL32 and Toll-like receptor 2 (TLR2) in induced inflammatory responses of human kidney cells. Site-directed mutagenesis was employed to individually mutate Ca(2+)-binding residues of LipL32 to Ala, and their effects subsequently were observed. These mutations abolished primarily the structural integrity of the calcium-binding cluster in LipL32. The binding assay and atomic force microscopy analysis further demonstrated the decreased binding capability of LipL32 mutants to TLR2. Inflammatory responses induced by LipL32 variants, as determined by TLR2 pathway intermediates hCXCL8/IL-8, hCCL2/MCP-1, hMMP7, and hTNF-α, were also lessened. In conclusion, the calcium-binding cluster of LipL32 plays essential roles in presumably sustaining LipL32 conformation for its proper association with TLR2 to elicit inflammatory responses in human renal cells.