Numerous surgical procedures have been developed to correct patellar tracking and improve patellofemoral symptoms by altering the Q-angle (the angle between the quadriceps load vector and the patellar tendon load vector). The influence of the Q-angle on knee kinematics has yet to be specifically quantified, however. In vitro knee simulation was performed to relate the Q-angle to tibiofemoral and patellofemoral kinematics. Six cadaver knees were tested by applying simulated hamstrings, quadriceps and hip loads to induce knee flexion. The knees were tested with a normal alignment. after increasing the Q-angle and after decreasing the Qangle. Increasing the Q-angle significantly shifted the patella laterally from 20" to 60" of knee flexion, tilted the patella medially from 20" to 80" of flexion, and rotated the patella medially froin 20" to 50" of flexion. Decreasing the Q-angle significantly tilted the patella laterally at 20" and from 50" to 80" of flexion, rotated the tibia externally from 30" to 60" of flexion, and increased the tibiofemoral varus orientation from 40" to 90" of flexion. The results show that an increase in the Q-angle could lead to lateral patellar dislocation or increased lateral patellofemoral contact pressurles. A Q-angle decrease may not shift the patella medially, but could increase the medial tibiofemoral contact pressure by increasing the varus orientation.
The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19) and the ensuing worldwide pandemic. The spread of the virus has had global effects such as activity restriction, economic stagnation, and collapse of healthcare infrastructure. Severe SARS-CoV-2 infection induces a cytokine storm, leading to acute respiratory distress syndrome (ARDS) and multiple organ failure, which are very serious health conditions and must be mitigated or resolved as soon as possible. Mesenchymal stem cells (MSCs) and their exosomes can affect immune cells by inducing anti-inflammatory macrophages, regulatory T and B cells, and regulatory dendritic cells, and can inactivate T cells. Hence, they are potential candidate agents for treatment of severe cases of COVID-19. In this review, we report the background of severe cases of COVID-19, basic aspects and mechanisms of action of MSCs and their exosomes, and discuss basic and clinical studies based on MSCs and exosomes for influenza-induced ARDS. Finally, we report the potential of MSC and exosome therapy in severe cases of COVID-19 in recently initiated or planned clinical trials of MSCs (33 trials) and exosomes (1 trial) registered in 13 countries on ClinicalTrials.gov.
Our institute has constructed a new treatment facility for carbon ion scanning beam therapy. The first clinical trials were successfully completed at the end of November 2011. To evaluate patient setup accuracy, positional errors between the reference Computed Tomography (CT) scan and final patient setup images were calculated using 2D-3D registration software. Eleven patients with tumors of the head and neck, prostate and pelvis receiving carbon ion scanning beam treatment participated. The patient setup process takes orthogonal X-ray flat panel detector (FPD) images and the therapists adjust the patient table position in six degrees of freedom to register the reference position by manual or auto- (or both) registration functions. We calculated residual positional errors with the 2D-3D auto-registration function using the final patient setup orthogonal FPD images and treatment planning CT data. Residual error averaged over all patients in each fraction decreased from the initial to the last treatment fraction [1.09 mm/0.76° (averaged in the 1st and 2nd fractions) to 0.77 mm/0.61° (averaged in the 15th and 16th fractions)]. 2D-3D registration calculation time was 8.0 s on average throughout the treatment course. Residual errors in translation and rotation averaged over all patients as a function of date decreased with the passage of time (1.6 mm/1.2° in May 2011 to 0.4 mm/0.2° in December 2011). This retrospective residual positional error analysis shows that the accuracy of patient setup during the first clinical trials of carbon ion beam scanning therapy was good and improved with increasing therapist experience.
The hip abductor muscles are considered important for gait and biomechanics of the hip joint; however, their specific function has not been defined precisely. The intensity of magnetic resonance imaging signals in skeletal muscle has been reported to increase immediately after exercise. Making use of this phenomenon, we evaluated the hip abductor muscles. Magnetic resonance imaging was performed after isometric exercise of the hip abductor in three positions (20 degrees of abduction, neutral, and 20 degrees of adduction). The abduction force of the hip was measured with a dynamometer, and electromyographic measurements were made simultaneously for the same hip positions. Additionally, magnetic resonance imaging was performed after one-legged stance. As the hip was more adducted, the signal intensity increased on the scans. The values for muscle force, as evaluated with the dynamometer and integrated electromyography, also supported the results. The increase in signal intensity of the gluteus minimus at 20 degrees of abduction and after one-legged stance was significantly greater than that of the gluteus medius (p < 0.0001 and p < 0.0001, respectively). The results of this study indicate that the gluteus minimus muscle, along with the gluteus medius, plays an important role in hip abduction, gait, and stabilization of the pelvis.
Our institution established a new treatment facility for carbon ion beam scanning therapy in 2010. The major advantages of scanning beam treatment compared to the passive beam treatment are the following: high dose conformation with less excessive dose to the normal tissues, no bolus compensator and patient collimator/ multi‐leaf collimator, better dose efficiency by reducing the number of scatters. The new facility was designed to solve several problems encountered in the existing facility, at which several thousand patients were treated over more than 15 years. Here, we introduce the patient handling system in the new treatment facility. The new facility incorporates three main systems, a scanning irradiation system (S‐IR), treatment planning system (TPS), and patient handling system (PTH). The PTH covers a wide range of functions including imaging, geometrical/position accuracy including motion management (immobilization, robotic arm treatment bed), layout of the treatment room, treatment workflow, software, and others. The first clinical trials without respiratory gating have been successfully started. The PTH allows a reduction in patient stay in the treatment room to as few as 7 min. The PTH plays an important role in carbon ion beam scanning therapy at the new institution, particularly in the management of patient handling, application of image‐guided therapy, and improvement of treatment workflow, and thereby allows substantially better treatment at minimum cost.PACS numbers: 87.56.‐v; 87.57.‐s; 87.55.‐x
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