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Method for Combined Observation of Serial Sections of Stented Arteries Embedded in Resin by Light Microscopy and Transmission Electron Microscopy
摘要： We have developed a new method for obtaining information on whole tissues by light microscopy (LM) and ultrastructural features by transmission electron microscopy (TEM). This method uses serial sections of a stented artery embedded in resin. Stents were implanted in porcine coronary arteries in this study. The heart was perfusion fixed in a 2% paraformaldehyde and 1.25% glutaraldehyde mixed solution. The stented artery was then removed, fixed in 1% osmium, embedded in Quetol 651 resin, and sectioned serially. For LM, the black color of osmium was removed from the section by immersion in periodic acid and hydrogen peroxide after deplasticization. These sections were stained with hematoxylin and eosin and Elastica–Masson trichrome stain. For TEM, thin sections were re-embedded in Quetol 812 resin by the resupinate method and cut into ultrathin sections. A clear, fine structure was obtained, and organelles, microvilli, and cell junctions in the endothelium were easily observed. The combined observation of adjacent specimens by LM and TEM enabled us to relate histopathological changes in the millimeter scale to those in the nanometer scale.
关键词： porcine,stent,resupinate method,coronary artery,epoxy resin,transmission electron microscopy,light microscopy
更新于2025-09-23 15:22:29
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Thermal effects of a novel electrosurgical device for focused preparation in breast surgery tested in a specified porcine tissue ex vivo breast model using infrared measurement
摘要： Purpose This article investigates the qualities and thermal effects of a novel electrosurgical device (PT) which has been designed by ERBE Elektromedizin GmbH, Germany, for the preparation of critical locations such as in skin-sparing or nipple-sparing techniques and compares it to a standard device (SD) in a porcine ex vivo breast model using an heat map generated by infrared thermography. Methods In total, 42 abdominal wall specimens of porcine tissue consisting of the skin and the underlying subcutaneous and muscle layer were alternately dissected using one of the devices and pre-settings. During the preparation with the two devices, the epicutaneous temperature was measured by an infrared camera (VarioCam, Jenoptik, Germany) and the maximum temperature as well as the slope of the temperature rise was analysed. Results The use of PT shows significantly lower values for ΔTmax compared to SD. This effect was independent from the chosen mode. Using the same instrument in different modes, the use of AutoCut mode showed a significant reduction of ΔTmax at all indicated time points (SD: p < 0.0001 and PT: p < 0.0001). In summary, the combination of AutoCut + PT showed the lowest rise in temperature, whereas the combination of DryCut + SD led to the highest rise in temperature. The temperature difference between these two settings was 13.84 °C, which means a possible temperature reduction of 67% can be achieved by the right choice of device and its tailored mode. Conclusions The novel PT shows a significant reduction in epicutaneous temperature and a significant reduction of the slope of temperature rise most probably by a more focused application of energy compared to SD.
关键词： Infrared thermography,Porcine model,Electrosurgery,Mastectomy
更新于2025-09-23 15:22:29
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Development and Validation of a Surface Plasmon Resonance Biosensor for Specific Detection of Porcine Serum Albumin in Food
摘要： Food allergies are a potential food safety and public health concern worldwide. To assure the safety of people who experience allergic reactions, it is necessary to establish effective and reliable methods for rapid detection of food allergens. This paper reports an innovative method for the rapid detection and analysis of porcine serum albumin (PSA), known as a major allergen in pork, based on a surface plasmon resonance (SPR) biosensor. The antibodies known to have a high bioactivity against PSA were verified by competitive indirect-ELISA and then immobilized on the SPR sensor surface, thus allowing them to capture PSA. The developed SPR demonstrated a linear range from 1.0 to 450 ng/mL for the measurement of PSA with a detection limit of 19.81 ng/mL. Within-day RSD (1.97–4.02%) and between-day RSD (1.88–4.15%) were no more than 5%. The SPR was evaluated for analysis of six commercial food samples and showed almost perfect agreement between the results obtained by ELISA test kits without significant differences (P > 0.05). Therefore, this assay permits accurate, specific, and sensitive detection of PSA in pork and pork products.
关键词： food safety,detection,SPR biosensor,food allergies,porcine serum albumin
更新于2025-09-23 15:21:01
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Ex vivo and animal study of the blue diode laser, Tm fiber laser, and their combination for laparoscopic partial nephrectomy
摘要： Background and Objectives: To evaluate the feasibility of using a novel blue diode laser (blue laser), a thulium fiber laser (Tm laser), and their combination as a directed‐energy surgical tool in laparoscopic partial nephrectomy (LPN). Study Design/Materials and Methods: The blue laser emitting at 442 nm, the Tm laser emitting at 1,940 nm wavelengths, and the combination of them were tested. First, cutting and coagulative abilities of the lasers were characterized ex vivo on porcine kidney in air and CO2. Histological staining was performed to assess the efficiency of ablation and coagulation. Next, experimental LPN was performed on a porcine model at zero ischemia. Upper and lower segments of both kidneys were resected. Total operation time and resection time were measured; bleeding and carbonization were evaluated. Results: Ex vivo data show that laser‐induced ablation and coagulation processes do not differ substantially between CO2 and air environments. Histological analysis of ex vivo incisions demonstrates that the blue laser produced deep ablation with relatively narrow coagulation zone, whereas Tm laser was less efficient in terms of ablation but possessed excellent coagulative properties. Experimental LPN revealed that the blue laser provided fast cutting with minimal carbonization, whereas Tm laser induced slow cutting with strong carbonization. The combination of the blue and Tm lasers provided the most promising results demonstrating the highest resection rate, almost carbonization free resection surface and clinically acceptable hemostasis enabling LPN without the need for vessel clamping. Conclusions: The blue laser can be efficiently utilized in LPN. Furthermore, the combination of the blue and Tm lasers into a single modality may be beneficial for further development of successful laser‐assisted LPN.
关键词： Tm fiber laser,laparoscopic partial nephrectomy,porcine model,blue diode laser
更新于2025-09-19 17:13:59
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[IEEE 2019 41st Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC) - Berlin, Germany (2019.7.23-2019.7.27)] 2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Hyperspectral imaging for thermal effect monitoring in in vivo liver during laser ablation
摘要： Thermal ablation is a minimally invasive technique used to induce a controlled necrosis of malignant cells by increasing the temperature in localized areas. This procedure needs an accurate and real-time monitoring of thermal effects to evaluate and control treatment outcome. In this work, a hyperspectral imaging (HSI) technique is proposed as a new and non-invasive method to monitor ablative therapy. HSI provides images of the target object in several spectral bands, hence the reflectance/absorbance spectrum for each pixel. This paper presents a preliminary and original HSI-based analysis of the thermal state in the in vivo porcine liver undergoing laser ablation. In order to compare the spectral response between treated and untreated areas of the organ, proper Regions of Interest (ROIs) were chosen on the hyperspectral images; for each ROI, the absorbance variation for the selected wavelengths (i.e., 630, 760, and 960nm, for deoxyhemoglobin, methemoglobin, and water respectively) was assessed. Results obtained during and after laser ablation show that the absorbance of the methemoglobin peaks increases up to 40% in the burned region with respect to the non-ablated one. Conversely, the relative change of deoxyhemoglobin and water peaks is less marked. Based on these results, absorbance threshold values were retrieved and used to visualize the ablation zone on the images. This preliminary analysis suggests that a combination of the absorbance information is essential to achieve a more accurate identification of the ablation region. The results encourage further studies on the correlation between thermal effects and the spectral response of biological tissues undergoing thermal ablation, for final clinical use.
关键词： laser ablation,absorbance spectrum,in vivo porcine liver,hyperspectral imaging,thermal ablation
更新于2025-09-16 10:30:52
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Effect of optical fiber diameter and laser emission mode (cw vs pulse) on tissue damage profile using 1.94?μm Tm:fiber lasers in a porcine kidney model
摘要： Purpose To evaluate the ablation capacity using two Thulium fiber lasers (TFL) in a porcine kidney model. Methods All tissue samples were mounted on a motorized stage for a precise speed of cutting. A continuous wave (cw) TFL and a super pulsed (SP) TFL were used at power settings of 60 and 120?W with 200 and 600?μm laser fibers. After lactate dehydrogenase staining, histological evaluation was performed to measure the vaporization volume (VV), ablation depth (AD), thermo-mechanical damage zones (TMZ), coagulation zones (CZ) and the carbonization grade (CG). Results At 120?W, no significant differences were seen between 200 and 600?μm fibers utilizing the cw TFL regarding VV (24.6 vs. 28.2?mm3/s), AD (5.6 vs. 5.7?mm), TMZ (0 vs. 0?mm2) and CZ (18.1 vs. 12.3?mm2). Using the SP TFL, no significant differences between both fiber diameters with regard to VV (4 vs. 6.2?mm3/s), AD (2.7 vs. 3.4?mm), TMZ (1 vs. 2.6?mm2) and CZ (3.1 vs. 2.2?mm2) at 120?W were found, respectively. However, the VV of the cw TFL at 60?W was significantly less compared to 120?W using 200 and 600?μm fibers, respectively, whereas the SP TFL did not show significant differences between 60 and 120?W with regard to VV. SP TFL showed a consistently lower CG compared to cw TFL. Conclusions This experiment suggests that there is no significant difference using 200 or 600?μm laser fibers in cw or SP TFLs. However, the cw TFL produces a coagulation zone three to five times larger than the SP TFL regardless of the fiber diameter.
关键词： Porcine kidney,In-vitro,Thulium fiber laser,Laser
更新于2025-09-11 14:15:04
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Fractional CO2 laser ablation of porcine burn scars after grafting: Is deeper better?
摘要： Introduction: Fractional CO2 lasers have been used in clinical settings to improve scarring following burn injury. Though used with increasing frequency, the appropriate laser settings are not well defined and overall efficacy of this therapy has not been definitively established. As it has been proposed that for thick hypertrophic scars proportionally greater fluence and thus deeper ablation into the scar tissue would be most effective, the goal of this study was to examine the role of ablation depth on scar outcomes in a highly-controlled porcine model for burn scars-after grafting. Methods: Properties of laser ablated wells were quantified on ex vivo pig skin as a function of laser energy (20, 70 or 150mJ). Full-thickness burn wounds were created on the dorsum of red Duroc pigs with the eschar excised and grafted with a split-thickness autograft meshed and expanded 1.5:1. After four weeks of healing, sites were treated with either 20, 70, or 150 mJ pulse energy from a fractional CO2 laser at 5% density or left untreated as a control. Sites were treated every four weeks with three total sessions. Scar area, pigmentation, erythema, roughness, histology, and biomechanics were evaluated prior to each laser treatment at day 28, 56, and 83, as well as four weeks after the final laser treatment, day 112. Additional biopsies were collected at day 112 for gene expression analysis. Results: The depth of the laser ablated wells increased with increasing pulse energy while the width of the wells was smaller in the 20mJ group and not significantly different in the 70 and 150mJ groups. Scar properties (area, color, biomechanics) were not significantly altered by laser therapy at any of the laser energies tested versus controls. Average scar roughness was improved by laser therapy in a dose dependent manner with scars treated with 150mJ of energy having the smoothest surface; however, these changes were not statistically significant. Assessment of matrix metalloproteinase 9 gene expression showed a slight upregulation in scars treated with 70 or 150 mJ versus control scars and scars treated with 20mJ pulse energy. Conclusion: The current study demonstrated that the properties of the ablative well (depth and width) are not linearly correlated with laser pulse energy, with only a small increase in well depth at energies between 70 and 150 mJ. Overall, the study suggests that there is little difference in outcomes as a function of laser energy. Fractional CO2 laser therapy did not result in any statistically significant benefit to scar properties assessed by quantitative, objective measures, thus highlighting the need for additional clinical investigation of laser therapy efficacy with non-treated controls and objective measures of outcome.
关键词： Power,Fractional CO2 laser,Porcine model,Quantitative assessment,Burn scars
更新于2025-09-11 14:15:04
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Optical transparency and electrical conductivity of intermediate filaments in Müller cells and single-wall carbon nanotubes
摘要： Presently we investigated the electrical conductivity and optical transparency of Müller cell intermediate filaments. For comparison, the same properties were also explored in the model system of single-wall carbon nanotubes. We report the method of separation and purification of porcine (Sus scrofa domestica) intermediate filaments, extracted from the retinal Müller cells. We also report experimental and theoretical methods of measurements and calculations of the resistivity and light transmission yield by the intermediate filaments and single wall carbon nanotubes. The measured resistivity values were (4.7 ± 0.3) × 10?4 Ω?m?1?cm2 and (2.8 ± 0.2) × 10?4 Ω?m?1?cm2 at 5 °C (278 K), for the intermediate filaments and single wall carbon nanotubes, respectively, being quite close to those of typical metals. We report a method for measuring the light energy transmission by these nanostructures. We found that they efficiently transfer excitation energy along their axis, with the light reemitted at their other end. The measured yields of transferred light energy were 0.50 ± 0.03 and 0.26 ± 0.02 for intermediate filaments and single wall carbon nanotubes, respectively (λexc = 546.1 nm; T = 288 K). The reported results are novel, providing a direct confirmation of the earlier proposed quantum mechanism of light energy transport in the inverted retina of vertebrates. Our data also show that Müller cell intermediate filaments, in addition to their cytoskeletal function, are capable of providing for the light energy transfer within the inverted retina. The data obtained enable a significant progress in our understanding of the high-contrast vision of the vertebrate eyes. The most important conclusion of the current study is the discovery of light energy propagation along natural biological nanofibers (intermediate filaments). This result is completely novel and unique, being reported for the first time.
关键词： Müller cell,Intermediate filament,Porcine retina,Light transmission,Electric conductivity
更新于2025-09-10 09:29:36
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Objective Evaluation of Zonular Weakness: Measurement of Lens Movement at the Start of Capsulorhexis Using Extracted Porcine Eyes
摘要： Objective: To evaluate the degree of zonular weakness based on lens movement at the start of capsulorhexis using extracted porcine eyes. Methods: Zonular dehiscence of 18°, 36°, and 54° was created and alternated with healthy areas into five zones to create a model simulation of weakness of the zonule of Zinn corresponding to dehiscence of 90°, 180°, and 270°. During continuous curvilinear capsulorhexis (CCC), an image displaying the anterior capsule grasped by a cystotome and another displaying the initial tear were captured, and the two images were superimposed to measure the movement distance of the cortical opacities created using a hook. Porcine eyes with no dehiscence were used as the control group. Results: Compared with a distance of 0.44 ± 0.13 mm in the control group, the cortical opacity movement distances in the weakness group with dehiscence corresponding to 90°, 180°, and 270° were 0.68 ± 0.27, 1.01 ± 0.22, and 1.32 ± 0.35 mm, respectively. Significant differences were observed between the control, 90°, 180°, and 270° dehiscence groups (P<0.001). Conclusion: This study revealed numerical data for the degree of weakness of the zonule of Zinn in porcine eyes. Clinical application of this method may be useful for establishing surgical procedures and prognoses for cataract surgery in patients with weakness of the zonule of Zinn.
关键词： Porcine eye,Capsulorhexis,Zonular weakness,Objective classification
更新于2025-09-04 15:30:14
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Quantification of Focal Outflow Enhancement Using Differential Canalograms
摘要： PURPOSE. To quantify regional changes of conventional out?ow caused by ab interno trabeculectomy (AIT). METHODS. Gonioscopic, plasma-mediated AIT was established in enucleated pig eyes. We developed a program to automatically quantify out?ow changes (R, package eye-canalogram, github.com) using a ?uorescent tracer reperfusion technique. Trabecular meshwork (TM) ablation was demonstrated with ?uorescent spheres in six eyes before formal out?ow quanti?cation with two-dye reperfusion canalograms in six additional eyes. Eyes were perfused with a central, intracameral needle at 15 mm Hg. Canalograms and histology were correlated for each eye. RESULTS. The pig eye provided a model with high similarity to AIT in human patients. Histology indicated ablation of TM and unroo?ng of most Schlemm’s canal segments. Spheres highlighted additional circumferential and radial out?ow beyond the immediate area of ablation. Differential canalograms showed that AIT caused an increase of out?ow of 17 6 5-fold inferonasally, 14 6 3-fold superonasally, and also an increase in the opposite quadrants with a 2 6 1-fold increase superotemporally, and 3 6 3 inferotemporally. Perilimbal speci?c ?ow image analysis showed an accelerated nasal ?lling with an additional perilimbal ?ow direction into adjacent quadrants. CONCLUSIONS. A quantitative, differential canalography technique was developed that allows us to quantify supraphysiological out?ow enhancement by AIT.
关键词： canalogram,glaucoma,trabecular meshwork,segmental out?ow,porcine eyes
更新于2025-09-04 15:30:14