Surgical treatment of axillary artery aneurysm

Aneurysms of the axillary artery are rare and dangerous lesions that threaten the upper extremities with vascular and neurologic compromise. Most can be treated effectively with surgical excision and vascular grafting. We retrospectively assessed 4 axillary artery aneurysms upon which we operated from February 1998 through March 2004. Three patients were admitted to our clinic for symptomatic axillary masses. The remaining patient was transported to our clinic emergently due to massive hemorrhage of an enlarging axillary mass that occurred during biopsy of the mass at another hospital. In this patient, the ruptured axillary artery aneurysm was diagnosed by means of emergent upper-extremity selective angiography. All patients were treated surgically by means of aneurysmectomy and graft interpositioning--with polytetrafluoroethylene grafts in 2 patients and saphenous vein grafts in the other 2. Surgical treatment of axillary artery aneurysms is of importance in avoiding thromboembolism and ischemia, which in turn can lead to gangrene and amputation of the affected extremity. For this reason, operative management of such cases should not be delayed.     

From the Cover: Breaking the diffraction limit of light-sheet fluorescence microscopy by RESOLFT

We present a plane-scanning RESOLFT [reversible saturable/switchable optical (fluorescence) transitions] light-sheet (LS) nanoscope, which fundamentally overcomes the diffraction barrier in the axial direction via confinement of the fluorescent molecular state to a sheet of subdiffraction thickness around the focal plane. To this end, reversibly switchable fluorophores located right above and below the focal plane are transferred to a nonfluorescent state at each scanning step. LS-RESOLFT nanoscopy offers wide-field 3D imaging of living biological specimens with low light dose and axial resolution far beyond the diffraction barrier. We demonstrate optical sections that are thinner by 5–12-fold compared with their conventional diffraction-limited LS analogs.Far-field nanoscopy (1, 2) methods discern features within subdiffraction distances by briefly forcing their molecules to two distinguishable states for the time period of detection. Typically, fluorophores are switched between a signaling “on” and a nonsignaling (i.e., dark) “off” state. Depending on the switching and fluorescence registration strategy used, these superresolution techniques can be categorized into coordinate-stochastic and coordinate-targeted approaches (2). The latter group of methods, comprising the so-called RESOLFT [reversible saturable/switchable optical (fluorescence) transitions] (1, 3–7) approaches, have been realized using patterns of switch-off light with one or more zero-intensity points or lines, to single out target point (zero-dimensional) or line (1D) coordinates in space where the fluorophores are allowed to assume the on state. The RESOLFT idea can also be implemented in the inverse mode, by using switch-on light and confining the off state. In any case, probing the presence of molecules in new sets of points or lines at every scanning step produces images.Owing to the nature of the on and off states involved––first excited electronic and ground state––stimulated emission depletion (STED) (3) and saturated structured illumination microscopy (SSIM) (8), which both qualify as variants of the RESOLFT principle, typically apply light intensities in the range of MW/cm² and above. Especially when imaging sensitive samples where photoinduced changes must be avoided, RESOLFT is preferably realized with fluorophores which lead to the same factor of resolution improvement at much lower intensities of state-switching light. Reversibly switchable fluorescent proteins (RSFPs) are highly suitable for this purpose (4–7, 9), as transitions between their metastable on and off states require 5 orders of magnitude lower threshold intensities than STED/SSIM to guarantee switch-off. Suitable spectral properties, relatively fast millisecond switching kinetics, and high photostability of recently developed yellow-green-emitting RSFPs like rsEGFP (5), rsEGFP2 (7), and rsEGFP(N205S) (10) compared with early RSFPs have indeed enabled RESOLFT nanoscopy in living cells and tissues. To date, RSFP-based RESOLFT has achieved resolution improvements by factors of 4–5 in rsEGFP2-labeled samples (7). To further reduce the imaging time, massive parallelization of scanning has been reported (10). However, the diffraction-limited axial resolution and lack of background suppression restrict applications to thin samples.Imaging applications typically require careful tuning of imaging parameters including speed, contrast, photosensitivity, and spatial resolution, depending on the information that is sought. Light-sheet fluorescence microscopy (LSFM) (11–15) stands out by its ability to balance most of these parameters for 3D imaging of living specimens. Recently reenacted as the selective plane illumination microscope (13), this microscopy mode has sparked increasing interest notably because of its short acquisition times in 3D imaging and low phototoxicity in living specimens. It excites fluorophores only in a thin diffraction-limited slice of the sample, perpendicular to the direction of fluorescence detection. The LS is generated by a cylindrical lens which focuses an expanded laser beam in only one direction onto the specimen or into the back-focal plane of an illumination objective. Alternatively, a single beam is quickly moved as a “virtual” LS (16) across a specimen section.In such conventional LSFM imaging, the lateral resolution is determined by the numerical aperture (N.A.) of the detection objective (17), whereas axial resolution is given by the LS thickness, provided the latter is thinner than the axial extent of the point-spread function describing the imaging process from the focal plane of the detecting lens to the camera. In a previous study, the axial resolution of LSFM was pushed to the diffraction limit by using the full aperture of the illumination objective with Gaussian beams; this was carried out for practically useful combinations of N.A. (e.g., 0.8 for both illumination and detection objectives) permissible in light of the geometrical constraints given by the objective lens dimensions (18). High-N.A. illumination comes with short Rayleigh ranges of Gaussian beams, which inherently limit the field of view (FOV) along the direction of illumination. Scanned Bessel beams for diffraction-limited excitation with a virtual LS (19–21) typically offer larger FOVs (22), but side lobes broaden the scanned LS in the axial direction and contribute to phototoxicity outside of the focal plane of detection (20). A more complex approach has used Bessel-beam excitation in combination with structured illumination to obtain near-isotropic (but still diffraction-limited) resolution as measured on fluorescent beads (20), albeit at the cost of acquisition time and reduced contrast due to fluorescence generated by the side lobes. In different work, axial resolution has also been improved about fourfold by acquiring two complementary orthogonal views of the sample using two alternating LSs, followed by computationally fusing image information with a deconvolution incorporating both views (23). LS approaches have also helped suppress out-of-focus background for single-molecule imaging in biological situations (e.g., in ref. 24), including at superresolution (25–27).Slight axial resolution improvement beyond the diffraction barrier has been demonstrated by overlapping a Gaussian excitation LS with a STED LS featuring a zero-intensity plane (28). Due to scattering and possibly additional aberrations caused by the wavelength difference between excitation and STED light, the maximal achievable resolution in biological specimens was severely limited. This was the case even in fixed samples. A successful application of LS-STED to living cells or organisms has not been reported. The relatively high average STED laser power required for high resolution gains calls for developing a coordinate-targeted superresolution LS approach with low-power operation, meaning a concept that does not solely rely on changing the way the light is directed to––or collected from––the sample, but a concept that harnesses an “on–off” transition for improved feature separation.     

Effects of glutamine on wound healing

Studies reporting the need for replacing amino acids such as glutamine (Gln), hydroxymethyl butyrate (HMB) and arginine (Arg) to accelerate wound healing are available in the literature. The primary objective of this study was to present the effects of Gln on tissue hydroxyproline (OHP) levels in wound healing. This study was conducted on 30 female Sprague Dawley rats with a mean weight of 230 ± 20 g. Secondary wounds were formed by excising 2 × 1 cm skin subcutaneous tissue on the back of the rats. The rats were divided into three equal groups. Group C (Control): the group received 1 ml/day isotonic solution by gastric gavage after secondary wound was formed. Group A (Abound): the group received 0·3 g/kg/day/ml Gln, 0·052 g/kg/day/ml HMB and 0·3 g/kg/day/ml Arg by gastric gavage after secondary wound was formed. Group R (Resource): the group received 0·3 g/kg/day/ml Gln by gastric gavage after secondary wound was formed. The OHP levels of the tissues obtained from the upper half region on the 8th day and the lower half region on the 21st day from the same rats in the groups were examined. Statistical analysis was performed using the statistics program SPSS version 17.0. No statistically significant differences were reported with regard to the OHP measurements on the 8th and 21st days (8th day: F = 0·068, P = 0·935 > 0·05; 21st day: F = 0·018, P = 0·983 > 0·05). The increase in mean OHP levels on the 8th and 21st days within each group was found to be statistically significant (F = 1146·34, P = 0·000 < 0·001). We conclude that in adults who eat healthy food, who do not have any factor that can affect wound healing negatively and who do not have large tissue loss at critical level, Gln, Arg and HMB support would not be required to accelerate secondary wound healing.     

Editorial

It has been proven that the jaw rehabilitation not only has a crucial role in treatment of both trismus and mandibular hypomobility but also in the rehabilitation of surgical conditions of the temporomandibular joint and the jaw.(1) Today, the commercially available jaw motion rehabilitation systems are specifically designed to treat these conditions.(2) These systems utilize repetitive passive motion and stretching to restore mobility and flexibility of the jaw musculature, associated joints and connective tissues. Major advantages of these systems are that they reduce patients' anxiety by allowing them to control the extent and length of each stretching and provide passive motion for effective jaw rehabilitation therapy allowing patients to perform their necessary therapy while continuing in their daily life.(3) However, these systems are very expensive and mostly unavailable in our country. So, a new alternative jaw motion rehabilitation device 'The Okbite' was developed recently in our hospital (Fig. 1). It is simply adapted from the commercially available nasal specula. The blades of the specula are cut distally and metal bite pads are attached to these sites. The lower bite pad was placed posteriorly and curved anatomically. This device can be produced in a custom-made form according the occlusal pattern and the size of the mandible of the patient. The metal bite pads are covered with plaster bandage by the patient for a soft bite. In our practice, we used this device for the rehabilitation of total temporomandibular joint prosthesis, temporomandibular gap arthroplasties and temporomandibular joint disorders with great success. It costs nearly 1/50 of the commercially available jaw motion rehabilitation systems with almost equal outcomes of pain relief and total mouth opening. The major disadvantage of this system is that it can mimic the anatomical motion pattern of the mandible to a limited extend. We propose the application of this Okbite system, which provides jaw rehabilitation in such conditions.     

Quality assessment of robot assisted thoracic surgical resection of non-small cell lung cancer: nodal upstaging and mediastinal recurrence

BackgroundRobot assisted thoracic surgery (RATS) is the minimally invasive surgical technique of choice for treatment of patients with non-small cell lung cancer (NSCLC), at the Isala Hospital. The aim of this study is to compare clinical and pathological staging results and mediastinal recurrence after RATS for anatomical resections of lung cancer as surrogate markers for quality of mediastinal lymph node dissection (MLND).MethodsThis single institute retrospective study was conducted in patients who underwent RATS for NSCLC. Excluded were patients with a history of concurrent malignant disease, with other previous neoplasms, with small cell lung cancer (SCLC) and patients in whom the robotic technique was converted to thoracotomy, prior to lymph node dissection. Data were obtained from the hospital database. The difference between clinical and pathological staging was expressed as upstaging and downstaging. Computed Tomography scanning was used for follow-up, and diagnosis of mediastinal recurrence.ResultsFrom November 2011 to May 2016, 227 patients underwent RATS at Isala Hospital Zwolle, the Netherlands. Of those, 130 (mean age, 69.5±9.3 years) met the eligibility criteria. Preoperative mediastinal lymph node staging was done by endoscopic ultrasound/endobronchial ultrasound, by positron emission tomography (PET) or mediastinoscopy. In 14 patients (10.8%) unforeseen N2 disease was found, 6 patients (4.6%) were upstaged from cN0 to pN2 and 8 patients (6.2%) were upstaged from cN1 to pN2. Mediastinal recurrence was detected in 7 patients (5.4%) during a median follow-up of 54 months (range, 1.5–102 months).ConclusionsIn patients with NSCLC, who underwent anatomical resection by means of RATS, an unforeseen N2 disease rate of 10.8% was demonstrated and a mediastinal recurrence rate of 5.4%. It is concluded that robotic surgery provides an accurate lymph node dissection.     

Production of chlorine-containing functional group doped graphene powders using Yucel's method as anode materials for Li-ion batteries

In this study, the one-step electrochemical preparation of chlorine doped and chlorine-oxygen containing functional group doped graphene-based powders was carried out by Yucel''s method, with the resultant materials used as anode materials for lithium (Li)-ion batteries. Cl atoms and ClO_x (x = 2, 3 or 4) groups, confirmed by X-ray photoelectron spectroscopy analysis, were covalently doped into the graphene powder network to increase the defect density in the graphene framework and improve the electrochemical performance of Li-ion batteries. The microscopic properties of the Cl-doped graphene powder were investigated by scanning electron microscopy and transmission electron microscopy (TEM) analyses. TEM analysis showed that the one-layer thickness of the graphene was approximately 0.33 nm. Raman spectroscopy analysis was carried out to determine the defect density of the graphene structures. The G peak obtained in the Raman spectra is related to the formation of sp² hybridized carbons in the graphene-based powders. The 2D peak seen in the spectra shows that the synthesized graphene-based powders have optically transparent structures. In addition, the number of sp² hybridized carbon rings was calculated to be 22, 19, and 38 for the Cl-GP1, Cl-GP2, and Cl-GOP samples, respectively. As a result of the charge/discharge tests of the electrodes as anodes in Li-ion batteries, Cl-GP2 exhibits the best electrochemical performance of 493 mA h g⁻¹ at a charge/discharge current density of 50 mA g⁻¹.

In this study, the one-step electrochemical preparation of chlorine doped and chlorine-oxygen containing functional group doped graphene-based powders was carried out by Yucel''s method, with the resultant materials used as anode materials for lithium (Li)-ion batteries.     

Principal curves as skeletons of tubular objects: locally characterizing the structures of axons

Developments in image acquisition technology make high volumes of neuron images available to neuroscientists for analysis. However, manual processing of these images is not practical and is infeasible for larger and larger scale studies. Reliable interpretation and analysis of high volume data requires accurate quantitative measures. This requires analysis algorithms to use mathematical models that inherit the underlying geometry of biological structures in order to extract topological information. In this paper, we first introduce principal curves as a model for the underlying skeleton of axons and branches, then describe a recursive principal curve tracing?(RPCT) method to extract this topology information from 3D microscopy imagery. RPCT first finds samples on the one dimensional principal set of the intensity function in space. Then, given an initial direction and location, the algorithm iteratively traces the principal curve in space using our principal curve tracing?(PCT) method. Recursive implementation of PCT provides a compact solution for extracting complex tubular structures that exhibit bifurcations.