Objective To provide a ventricular assist device for patients with heart failure, Fu Wai （FW） axial blood pump was developed for partly or totally to assist the left ventricular function. Vitro hemolysis and animals tests were also employed to test the hydromechanics and hemocompatibility of the FW left ventricular assist devices developed in Fu Wai hospital. Methods Using vitro test loop, FW axial blood pump has been used to evaluate the performance of hemolysis， the pump has also been tested for hemolysis characteristic through five sheep experiments. Results At 8 400 r/min, the pump generates 5 L/min flow against 100 mm Hg, the normalized index of hemolysis (NIH) was0.17±0.06 mg/L. The plasma free hemoglobin of in vivo tests was around 30 mg/dl. Conclusion The results obtained in vitro and in vivo testing indicate an acceptable design for the blood pump, further in vivo tests will be performed before clinical use.
Objective To review the in vivo imaging research progress of two-photon microscopy (TPM) in spinal cord. Methods The recent literature concerning in vivo two-photon imaging of axon, microglia, and calcium in transgenic mice spinal cord was extensively consulted and reviewed. Results In vivo two-photon imaging of spinal cord provide dynamic information about axonal degeneration and regeneration, microglial accumulation, and calcium influx after spinal cord injury. Conclusion TPM in vivo imaging study on spinal cord will provide theoretical foundation for pathophysiologic process of spinal cord injury.
This paper investigates the variation of lung tissue dielectric properties with tidal volume under in vivo conditions to provide reliable and valid a priori information for techniques such as microwave imaging. In this study, the dielectric properties of the lung tissue of 30 rabbits were measured in vivo using the open-end coaxial probe method in the frequency band of 100 MHz to 1 GHz, and 6 different sets of tidal volumes (30, 40, 50, 60, 70, 80 mL) were set up to study the trends of the dielectric properties, and the data at 2 specific frequency points (433 and 915 MHz) were analyzed statistically. It was found that the dielectric coefficient and conductivity of lung tissue tended to decrease with increasing tidal volume in the frequency range of 100 MHz to 1 GHz, and the differences in the dielectric properties of lung tissue for the 6 groups of tidal volumes at 2 specific frequency points were statistically significant. This paper showed that the dielectric properties of lung tissue tend to vary non-linearly with increasing tidal volume. Based on this, more accurate biological tissue parameters can be provided for bioelectromagnetic imaging techniques such as microwave imaging, which could provide a scientific basis and experimental data support for the improvement of diagnostic methods and equipment for lung diseases.
ObjectiveTo investigate the changes in the nerve fiber layer of the cornea in patients with demyelinating optic neuritis (DON) and its correlation with visual acuity. MethodsA cross-sectional study. From March 2021 to July 2022, 27 cases (39 eyes) of DON patients diagnosed in the Department of Neurology and Ophthalmology of Beijing Tongren Hospital Affiliated to Capital Medical University were enrolled in this study. According to the serological test results, the patients were divided into aquaporin 4 antibody associated optic neuritis (AQP4-ON group) and myelin oligodendrocyte glycoprotein antibody associated optic neuritis (MOG-ON group), with 15 cases (19 eyes) and 12 cases (20 eyes) respectively. According to previous history of glucocorticoid treatment, the patients were divided into glucocorticoid treated group and non-glucocorticoid treated group, with 17 cases (27 eyes) and 10 cases (12 eyes) respectively. Twenty healthy volunteers (20 eyes) with age- and gender-matched were selected as the control group. All eyes underwent best corrected visual acuity (BCVA) and in vivo confocal microscopy (IVCM) examinations. BCVA was performed using Snellen's standard logarithmic visual acuity chart, which was converted into logarithmic minimum angle resolution (logMAR) visual acuity during statistics. The corneal nerve fiber length (CNFL), corneal nerve fiber density (CNFD), corneal nerve fiber branch length (CNBL), corneal nerve fiber branch density (CNBD) and the density of corneal dendritic cells (DC) were detected by IVCM examination. Parameter comparison between groups by t-test and Kruskal-Wallis rank sum test. The correlation between logMAR BCVA and pamameters of corneal nerve fibers were analyzed using Spearman analysis. ResultsThe CNFL, CNFD, and CNBL of the DON group and the control group were (10.67±2.55) mm/mm2, (57.78±12.35) root/mm2, (3.27±1.34) mm/mm2, and (13.74±3.05) mm/mm2, (70.95±13.14) root/mm2, and (4.22±1.03) mm/mm2, respectively; the difference in CNFL, CNFD, and CNBL between the two groups were statistically significant (t=4.089, 3.795, 2.773; P＜0.05). The CNFL, CNBL, and CNBD of the affected eyes in the MOG-ON group and AQP4-ON group were (12.02±2.13) mm/mm2, (3.80±1.19) mm/mm2, (47.97±8.86) fibers/mm2, and (9.25±2.19) mm/mm2, (2.72±1.19) mm/mm2, (39.43±13.86) fibers/mm2, respectively; the differences in CNFL, CNBL, and CNBD between the two groups were statistically significant (t=－4.002, －2.706, －2.306; P＜0.05). The corneal DC density of the patients in the hormone treated group and the non-hormone treated group was (24.43±8.32) and (41.22±9.86) cells/mm2, respectively. The difference in corneal DC density between the two subgroups was statistically significant (P＜0.001). Correlation analysis showed that there was a significant negative correlation between logMAR BCVA and CNBL and CNFL in patients with DON (r=－0.422, －0.456; P＜0.05). ConclusionsThere are different degrees of corneal nerve fiber damage in patients with different types of DON. There was a negative correlation between BCVA and the length of corneal nerve fibers.
Objective To monitor the importance of establishing lung cancer models for immunological treatment through in vivo imaging system (IVIS). Methods In this study, a new optical bioluminescence IVIS was used to confirm the tumour formation and luminescence in male BALB/c nude mice by injecting A549-luc cells. First, A549-luc cells which expressed luciferase stably were transferred into nude mice by tail vein injection in order to establish a stable and reliable model of lung cancer. Then, D-fluorescein potassium salt was intraperitoneally injected every other week. The tumor formation and growth were dynamically observed on day 7th, 14th and 21st by IVIS Spectrum and pathological exam with hematoxylin-eosin staining. Results Animal model of lung cancer was successfully established, and the development of lung cancer was effectively monitored by IVIS real-time fluorescence value which was consistent with pathological exam, and tumor volume was correlated with fluorescence intensity (r=0.7996, P<0.01). Conclusions IVIS has multiple benefits, including high sensitivity and specificity, simple operation, and no radiation. IVIS Spectrum can measure the fluorescence of tumor formed by injection of A549-luc cells in nude mice metastasis of lung cancer in a non-invasive, real-time and dynamic mode, which is worthy of promotion for using in clinical research.
ObjectiveTo review the researches of in vivo kinematics in lumbar degenerative spondylol isthesis (DS). MethodsRelated literature concerning the in vivo kinematics in patients with lumbar DS was extensively reviewed and comprehensively analyzed in 4 terms of the instabil ity of lumbar DS, vertebral motion pattern, the morphological changes of spinal canal, and intraoperative biomechanical measurement. ResultsWhether there is lumbar segmental instabil ity in lumbar DS patients is still controversial, which should be based on degenerative stage of lumbar spine and grade of slip. The hypomobility of the lumbar spinous processes and the facet joint is seen in DS. The diameter, cross-sectional area, and volume of spinal canal in lumbar DS patients are significantly smaller than those of the normal control. Because of its invasive procedure and medical ethics, the use of the intraoperative measurement device is limited. These reported researches of in vivo kinematics in DS are almost on the sagittal plane. However, few data have been reported on the 6-degree-of-freedom (6DOF) kinematics of the diseased levels under physiological loading conditions. ConclusionThe 6DOF kinematics data can accurately reflect the segmental motion characteristics in lumbar DS patients, recent studies have been reported, further studies are still needed.
ObjectiveTo evaluate the most efficient method for transfection of human umbilical cord mesenchymal stem cells (HUMCSs) in vivo. MethodsHUCMSCs were isolated from human umbilical cord and cultured, which were labelled by PKH26 and lentivirus-GFP, then were observed by using a fluorescence microscope. Sixty SD rats were randomly divided into PKH26 transfection group and lentivirus-GFP transfection group. The right hepatic lobe of rat was resected, then the transfected stem cells were injected into portal vein. The rats were sacrificed on day 3, 8, and 13 after transfection. The liver specimens were observed by using a fluorescence microscope. Flow cytometry was used to evaluate the percentage of transfected stem cells and the apoptotic stem cells. ResultsThe third generation of HUCMSCs labelled by PKH26 and lentivirus-GFP were spindle shaped. PKH26 red dye was evenly distributed in the cell membrane of HUCMSCs and could be clearly labelled. The HUCMSCs labelled by lentivirus-GFP were green fluorescence under the fluorescence microscope, and it was clear and stable. The HUCMSCs were clear and could be clearly distinguished on day 3 after transfection by two methods in vivo. As the time went by, red was faded and blurred, then was gradually disappeared on day 13 after transfection in the HUCMSCs stansfected by PKH26; but the color in the HUCMSCs stansfected by lentivirus-GFP were clear at all the time points. The transfection rate of the lentivirus-GFP was significantly higher that that of the PKH26 (P < 0.05), the rate of apoptotic stem cells had no significant differences at all the time points between these two groups (P > 0.05). ConclusionLentivirus-GFP transfection is a higher efficient method for stem cell labelling in vivo, it could be used to observe transplantation cells for a long time in future.
ObjectiveTo observe the in vivo three-dimensional (3-D) transient motion characteristics of the subaxial cervical spine in healthy adults. MethodsSeventeen healthy volunteers without cervical spine related diseases were recruited for this study, including 8 males and 9 females with a mean age of 26 years (range, 23-41 years). The vertebral segment motion of each subject was reconstructed with CT, and Rhinoceros 4.0 solid modeling software were used for 3-D reconstruction model of the subaxial cervical spine. In vivo cervical vertebral motion in flexionextension, left and right bending, left and right rotation was observed with dual fluoroscopic imaging system (DFIS). Coordinate systems were established at the vertebral center of C3-7 to obtain the intervertebral range of motion (ROM) and displacement at C3, 4, C4, 5, C5, 6, and C6, 7. The X-axis pointed to the left along the coronal plane, the Y-axis pointed to the back along the sagittal plane, and the Z-axis perpendicular to the X-Y plane pointed to the head. The ROM along X, Y, and Z axises were represented by rotation in flexion-extension (α), in left-right bending (β), and in left-right twisting (γ) respectively, and the displacement in left-right direction (x), in anterior-posterior direction (y), and in proximaldistal direction (z), respectively. ResultsIn flexion and extension, the displacement in anterior-posterior direction of C6, 7 was significantly less that of other segments (P<0.05), but the displacements in left-right direction and in proximaldistal direction showed no significant difference between segments (P>0.05); the ROM values in flexion-extension of C4, 5 and C5, 6 were significantly larger than those of C3, 4 and C6, 7 (P<0.05), and the ROM value in left-right twisting of C4, 5 was significantly larger than those of C5, 6 and C6, 7 (P<0.05), but the ROM value in left-right bending showed no significant difference between segments (P>0.05). In left and right bending, there was no significant difference in the displacement between other segments (P>0.05) except that the displacement in anterior-posterior direction of C3, 4 was significantly larger than that of C4, 5 (P<0.05), and that the displacement in proximal-distal direction of C6, 7 was significantly less than that of C3, 4 and C4, 5 (P<0.05); no significant difference was shown in the ROM value between segments (P>0.05), except that the ROM value in left-right twisting of C3, 4 was significantly larger than that of C5, 6 and C6, 7 (P<0.05). In left and right rotation, the ROM value in left-right twisting of C3, 4 was significantly larger than that of C4, 5 and C6, 7 (P<0.05), and the displacement and ROM value showed no significant differece between other segments (P>0.05). ConclusionThe intervertebral motions of the cervical spine show different characters at different levels. And the 6-degree-of-freedom data of the cervical vertebrae are obtained, these data may provide new information for the in vivo kinematics of the cervical spine.
In vivo transplantation of tracheal grafts utilizes natural environment in vivo to improve cell adhesion, growth and scaffold properties, which can not only promote graft revascularization, but also induce immune tolerance and increase postoperative survival rate. Decellularized trachea with stem cells covering the outside layer and airway epithelial cells covering the inside layer can achieve complete mucosa re-epithelialization, cartilage cell growth and revascularization, using own body as a natural bioreactor to boost the maturity of tissue engineered trachea. Then transplantation at a normotopic in situ positioning is performed. This transplantation strategy provides a promising approach for the treatment of long-segment tracheal defects. This review focuses on the significance and research progress of constructing tissue engineered trachea in vivo.
Near-infrared fluorescence imaging technology, which possesses superior advantages including real-time and fast imaging, high spatial and temporal resolution, and deep tissue penetration, shows great potential for tumor imaging in vivo and therapy. Ⅰ-Ⅲ-Ⅵ quantum dots exhibit high brightness, broad excitation, easily tunable emission wavelength and superior stability, and do not contain highly toxic heavy metal elements such as cadmium or lead. These advantages make Ⅰ-Ⅲ-Ⅵ quantum dots attract widespread attention in biomedical field. This review summarizes the recent advances in the controlled synthesis of Ⅰ-Ⅲ-Ⅵ quantum dots and their applications in tumor imaging in vivo and therapy. Firstly, the organic-phase and aqueous-phase synthesis of Ⅰ-Ⅲ-Ⅵ quantum dots as well as the strategies for regulating the near-infrared photoluminescence are briefly introduced; secondly, representative biomedical applications of near-infrared-emitting cadmium-free quantum dots including early diagnosis of tumor, lymphatic imaging, drug delivery, photothermal and photodynamic therapy are emphatically discussed; lastly, perspectives on the future directions of developing quantum dots for biomedical application and the faced challenges are discussed. This paper may provide guidance and reference for further research and clinical translation of cadmium-free quantum dots in tumor diagnosis and treatment.