Kinematics of the Midtarsal Joint During Standing Leg Rotation

2002 ◽  
Vol 92 (2) ◽  
pp. 77-81 ◽  
Author(s):  
Christopher Nester ◽  
Peter Bowker ◽  
Peter Bowden

Building on previous work that was cadaver based or involved invasive techniques, this study quantifies the kinematics of an approximation of the midtarsal joint with a noninvasive method. Three-dimensional kinematic data describing the motion of the forefoot and heel during transverse plane rotation of the leg were collected from 25 subjects by means of reflective markers and four infrared cameras. The motion between these segments was assumed to be the best possible clinical approximation of the midtarsal joint. The kinematic characteristics of the midtarsal joint were described in terms of the range and direction of motion in each cardinal body plane, the ratio of the range of motion in each plane, and the orientation of the axis of rotation. The characteristics of the midtarsal joint changed during the range of motion; thus, multiple axes of rotation could be calculated and joint characteristics were varied among subjects. The results of this in vivo method were generally consistent with those of cadaver studies and invasive in vivo studies. (J Am Podiatr Med Assoc 92(2): 77-81, 2002)

2020 ◽  
Vol 45 (5) ◽  
pp. 501-507
Author(s):  
Lisa Reissner ◽  
Olga Politikou ◽  
Gabriella Fischer ◽  
Maurizio Calcagni

We recorded the dart-throwing motion and basic motion tasks in patients following radioscapholunate fusion and midcarpal fusion with a three-dimensional motion capture system in vivo, using digital infrared cameras to track the movement of reflective skin markers on the hand and forearm. During the dart-throwing motion, 20 healthy volunteers showed a median range of motion of 107°. As expected, patients had significantly reduced wrist range of motion during basic motion tasks and dart-throwing motion compared with the healthy controls, except for ulnar flexion occurring in the dart-throwing motion in patients treated by midcarpal fusion and radial deviation after midcarpal fusion or radioscapholunate fusion. In addition, patients who had undergone radioscapholunate fusion had significantly reduced range of motion during dart-throwing motion compared with patients after midcarpal fusion.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3207
Author(s):  
Kumaresan Sakthiabirami ◽  
Vaiyapuri Soundharrajan ◽  
Jin-Ho Kang ◽  
Yunzhi Peter Yang ◽  
Sang-Won Park

The design of zirconia-based scaffolds using conventional techniques for bone-regeneration applications has been studied extensively. Similar to dental applications, the use of three-dimensional (3D) zirconia-based ceramics for bone tissue engineering (BTE) has recently attracted considerable attention because of their high mechanical strength and biocompatibility. However, techniques to fabricate zirconia-based scaffolds for bone regeneration are in a stage of infancy. Hence, the biological activities of zirconia-based ceramics for bone-regeneration applications have not been fully investigated, in contrast to the well-established calcium phosphate-based ceramics for bone-regeneration applications. This paper outlines recent research developments and challenges concerning numerous three-dimensional (3D) zirconia-based scaffolds and reviews the associated fundamental fabrication techniques, key 3D fabrication developments and practical encounters to identify the optimal 3D fabrication technique for obtaining 3D zirconia-based scaffolds suitable for real-world applications. This review mainly summarized the articles that focused on in vitro and in vivo studies along with the fundamental mechanical characterizations on the 3D zirconia-based scaffolds.


Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3088
Author(s):  
Mariana Matias ◽  
Jacinta O. Pinho ◽  
Maria João Penetra ◽  
Gonçalo Campos ◽  
Catarina Pinto Reis ◽  
...  

Melanoma is recognized as the most dangerous type of skin cancer, with high mortality and resistance to currently used treatments. To overcome the limitations of the available therapeutic options, the discovery and development of new, more effective, and safer therapies is required. In this review, the different research steps involved in the process of antimelanoma drug evaluation and selection are explored, including information regarding in silico, in vitro, and in vivo experiments, as well as clinical trial phases. Details are given about the most used cell lines and assays to perform both two- and three-dimensional in vitro screening of drug candidates towards melanoma. For in vivo studies, murine models are, undoubtedly, the most widely used for assessing the therapeutic potential of new compounds and to study the underlying mechanisms of action. Here, the main melanoma murine models are described as well as other animal species. A section is dedicated to ongoing clinical studies, demonstrating the wide interest and successful efforts devoted to melanoma therapy, in particular at advanced stages of the disease, and a final section includes some considerations regarding approval for marketing by regulatory agencies. Overall, considerable commitment is being directed to the continuous development of optimized experimental models, important for the understanding of melanoma biology and for the evaluation and validation of novel therapeutic strategies.


2016 ◽  
Vol 68 (1) ◽  
pp. 125-133 ◽  
Author(s):  
Qiuyan Zhang ◽  
Dongli Li ◽  
Yue Liu ◽  
Hui Wang ◽  
Changyuan Zhang ◽  
...  

Three curcumin analogs(S1-S3) containing sulfone were investigated for their effects on human prostate cancer PC-3, colon cancer HT-29, lung cancer H1299 and pancreatic cancer BxPC-3 cells. The three compounds were approximately 16-to 96-fold more active than curcumin in these cell lines as determined by the MTT assay. The effects of these compounds on cell growth were further studied in prostate cancer PC-3 cells in both two dimensional (2D) and three dimensional (3D) cultures. S1-S3strongly inhibited the growth and induced cell death in PC-3 cells, and the effects of these compounds were associated with suppression of nuclear factor kappa B (NF-?B) transcriptional activity. Moreover, treatment of PC-3 cells with all three compounds caused a decrease in the level of phosphorylated signal transducer and activator of transcription-3 (p-STAT3) (Tyr705),but not p-STAT3(Ser727). Only S1and S2decreased the presence of phosphorylated Akt (p-Akt) in PC-3 cells. These curcumin analogs warrant further in vivo studies for anticancer activities in suitable animal models.


Author(s):  
Pia Schneeweiss ◽  
Dorin Panescu ◽  
Dominik Stunder ◽  
Mark W. Kroll ◽  
Christopher J. Andrews ◽  
...  

AbstractElectric contact currents (CC) can cause muscle contractions, burns, or ventricular fibrillation which may result in life-threatening situations. In vivo studies with CC are rare due to potentially hazardous effects for participants. Cadaver studies are limited to the range of tissue’s electrical properties and the utilized probes’ size, relative position, and sensitivity. Thus, the general safety standards for protection against CC depend on a limited scientific basis. The aim of this study was therefore to develop an extendable and adaptable validated numerical body model for computational CC dosimetry for frequencies between DC and 1 MHz. Applying the developed model for calculations of the IEC heart current factors (HCF) revealed that in the case of transversal CCs, HCFs are frequency dependent, while for longitudinal CCs, the HCFs seem to be unaffected by frequency. HCFs for current paths from chest or back to hand appear to be underestimated by the International Electrotechnical Commission (IEC 60479-1). Unlike the HCFs provided in IEC 60479-1 for longitudinal current paths, our work predicts the HCFs equal 1.0, possibly due to a previously unappreciated current flow through the blood vessels. However, our results must be investigated by further research in order to make a definitive statement. Contact currents of frequencies from DC up to 100 kHz were conducted through the numerical body model Duke by seven contact electrodes on longitudinal and transversal paths. The resulting induced electric field and current enable the evaluation of the body impedance and the heart current factors for each frequency and current path.


1994 ◽  
Vol 116 (3) ◽  
pp. 331-336 ◽  
Author(s):  
Ding-Yu Fei ◽  
James D. Thomas ◽  
Stanley E. Rittgers

Flow in distal end-to-side anastomoses of iliofemoral artery bypass grafts was simulated using a steady flow, three-dimensional numerical model. With the proximal artery occluded, anastomotic angles were varied over 20, 30, 40, 45, 50, 60 and 70 deg while the inlet Reynolds numbers were 100 and 205. Fully developed flow in the graft became somewhat skewed toward the inner wall with increasing angle for both Reynolds numbers. Separated flow regions were seen along the inner arterial wall (toe region) for angles ≥ 60 deg at Re = 100 and for angles ≥ 45 deg at Re = 205 while a stagnation point existed along the outer arterial wall (floor region) for all cases which moved downstream relative to the toe of the anastomosis with decreasing angles. Normalized shear rates (NSR) along the arterial wall varied widely throughout the anastomotic region with negative values seen in the separation zones and upstream of the stagnation points which increased in magnitude with angle. The NSR increased with distance downstream of the stagnation point and with magnitudes which increased with the angle. Compared with observations from chronic in vivo studies, these results appear to support the hypothesis of greater intimal hyperplasia occurring in regions of low fluid shear.


Heart ◽  
2012 ◽  
Vol 98 (15) ◽  
pp. 1146-1152 ◽  
Author(s):  
Wendy Tsang ◽  
Michael G Bateman ◽  
Lynn Weinert ◽  
Gian Pellegrini ◽  
Victor Mor-Avi ◽  
...  

2017 ◽  
Vol 67 (2) ◽  
pp. 149-168 ◽  
Author(s):  
Pijush Kumar Paul ◽  
Alongkot Treetong ◽  
Roongnapa Suedee

AbstractIn this study, we investigate molecularly imprinted polymers (MIPs), which form a three-dimensional image of the region at and around the active binding sites of pharmaceutically active insulin or are analogous to b cells bound to insulin. This approach was employed to create a welldefined structure within the nanospace cavities that make up functional monomers by cross-linking. The obtained MIPs exhibited a high adsorption capacity for the target insulin, which showed a significantly higher release of insulin in solution at pH 7.4 than at pH 1.2. In vivo studies on diabetic Wistar rats showed that the fast onset within 2 h is similar to subcutaneous injection with a maximum at 4 h, giving an engaged function responsible for the duration of glucose reduction for up to 24 h. These MIPs, prepared as nanosized material, may open a new horizon for oral insulin delivery.


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