Clinical Biomechanics: Contributions to the Medical Treatment of Physical Abnormalities

2012 ◽  
Vol 1 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Joseph Hamill ◽  
George Gorton ◽  
Peter Masso

Biomechanics is defined as the application of the laws of mechanics to the study or structure and function of movement. It is a relatively new subdiscipline to the domain of kinesiology. Biomechanics was initially closely associated with the study of sports technique. However, over the years, biomechanics has taken on a much more diverse field of study. In this paper, we will describe the contributions that biomechanics has made to the area of clinical biomechanics research in terms of clinical assessment and outcomes and the design of clinical apparatus. The first example examines a clinical assessment of a cerebral palsy child. The goals of such a clinical assessment are 1) to determine the primary problems with the locomotion capabilities of the individual, 2) to recommend treatment options, and 3) to evaluate treatment outcomes. In the second example, a procedure is described for designing braces for scoliosis patients. For this example, a three-dimensional digital twin is developed using a scanning technique. This example illustrates the research conducted on developing a technique to noninvasively and safely determine the torso deformities resulting from scoliosis. While these examples are but two of a wide variety of examples that could be used, they illustrate the contribution of biomechanics to the clinical world.

2001 ◽  
Vol 43 (6) ◽  
pp. 135-135 ◽  
Author(s):  
J.-U. Kreft ◽  
J. W. Wimpenny

We have simulated a nitrifying biofilm with one ammonia and one nitrite oxidising species in order to elucidate the effect of various extracellular polymeric substance (EPS) production scenarios on biofilm structure and function. The individual-based model (IbM) BacSim simulates diffusion of all substrates on a two-dimensional lattice. Each bacterium is individually simulated as a sphere of given size in a continuous, three-dimensional space. EPS production kinetics was described by a growth rate dependent and an independent term (Luedeking-Piret equation). The structure of the biofilm was dramatically influenced by EPS production or capsule formation. EPS production decreased growth of producers and stimulated growth of non-producers because of the energy cost involved. For the same reason, EPS accumulation can fall as its rate of production increases. The patchiness and roughness of the biofilm decreased and the porosity increased due to EPS production. EPS density was maximal in the middle of the vertical profile. Introduction of binding forces between like cells increased clustering.


Author(s):  
Peter Sterling

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.


PLoS ONE ◽  
2017 ◽  
Vol 12 (3) ◽  
pp. e0171355 ◽  
Author(s):  
Roshni Bhattacharya ◽  
Peter W. Rose ◽  
Stephen K. Burley ◽  
Andreas Prlić

2005 ◽  
Vol 73 (10) ◽  
pp. 6332-6339 ◽  
Author(s):  
Charlotte M. A. Linde ◽  
Susanna Grundström ◽  
Erik Nordling ◽  
Essam Refai ◽  
Patrick J. Brennan ◽  
...  

ABSTRACT Granulysin and NK-lysin are homologous bactericidal proteins with a moderate residue identity (35%), both of which have antimycobacterial activity. Short loop peptides derived from the antimycobacterial domains of granulysin, NK-lysin, and a putative chicken NK-lysin were examined and shown to have comparable antimycobacterial but variable Escherichia coli activities. The known structure of the NK-lysin loop peptide was used to predict the structure of the equivalent peptides of granulysin and chicken NK-lysin by homology modeling. The last two adopted a secondary structure almost identical to that of NK-lysin. All three peptides form very similar three-dimensional (3-D) architectures in which the important basic residues assume the same positions in space. The basic residues in granulysin are arginine, while those in NK-lysin and chicken NK-lysin are a mixture of arginine and lysine. We altered the ratio of arginine to lysine in the granulysin fragment to examine the importance of basic residues for antimycobacterial activity. The alteration of the amino acids reduced the activity against E. coli to a larger extent than that against Mycobacterium smegmatis. In granulysin, the arginines in the loop structure are not crucial for antimycobacterial activity but are important for cytotoxicity. We suggest that the antibacterial domains of the related proteins granulysin, NK-lysin, and chicken NK-lysin have conserved their 3-D structure and their function against mycobacteria.


2015 ◽  
Vol 5 (1) ◽  
Author(s):  
A.E. Naas ◽  
A.K. MacKenzie ◽  
B. Dalhus ◽  
V.G.H. Eijsink ◽  
P.B. Pope

Abstract Previous gene-centric analysis of a cow rumen metagenome revealed the first potentially cellulolytic polysaccharide utilization locus, of which the main catalytic enzyme (AC2aCel5A) was identified as a glycoside hydrolase (GH) family 5 endo-cellulase. Here we present the 1.8 Å three-dimensional structure of AC2aCel5A and characterization of its enzymatic activities. The enzyme possesses the archetypical (β/α)8-barrel found throughout the GH5 family and contains the two strictly conserved catalytic glutamates located at the C-terminal ends of β-strands 4 and 7. The enzyme is active on insoluble cellulose and acts exclusively on linear β-(1,4)-linked glucans. Co-crystallization of a catalytically inactive mutant with substrate yielded a 2.4 Å structure showing cellotriose bound in the −3 to −1 subsites. Additional electron density was observed between Trp178 and Trp254, two residues that form a hydrophobic “clamp”, potentially interacting with sugars at the +1 and +2 subsites. The enzyme’s active-site cleft was narrower compared to the closest structural relatives, which in contrast to AC2aCel5A, are also active on xylans, mannans and/or xyloglucans. Interestingly, the structure and function of this enzyme seem adapted to less-substituted substrates such as cellulose, presumably due to the insufficient space to accommodate the side-chains of branched glucans in the active-site cleft.


2000 ◽  
Author(s):  
G. L. Bowlin ◽  
Barbara Wise ◽  
L. Terracio ◽  
D. G. Simpson

Abstract Fundamental research has defined many of the mechanistic events that mediate congenital malformations and the pathological disease processes that alter cardiac structure and function. Despite these efforts, there are a limited number of clinical treatment options available for many of these conditions. In many cases, even for disease processes that cause focal defects in the ventricular wall, the only viable treatment is the complete replacement of the damaged organ by transplant. Unfortunately, the supply of cardiac tissue that is available for transplant therapy remains chronically, and critically, short of demand. The reconstruction of a specific domain of dysfunctional ventricular tissue with a cell-based therapy is a potential avenue of treatment. One of the most direct strategies in this type of treatment regime is the injection of a suspension of fetal or neonatal cardiac myocytes into the injured domain. In small animal models, two limitations have become apparent with this strategy. First, differentiated myocytes do not undergo migration when they are injected into scar tissue and as a result they tend to remain concentrated in the vicinity of the injection site. Second, the myocytes that survive in the injection site are not well integrated into the healthy tissue and contract at rates that are independent of the surrounding myocardium. The long-term objective of this project is to circumvent the limitations of injection therapy by fabricating a cardiac muscle prosthesis that mimics the three dimensional architecture of the intact heart.


Author(s):  
Rogan Corbridge ◽  
Nicholas Steventon

Structure and function of the nose 160 Rhinitis 164 Types of rhinitis 165 Medical treatment of rhinitis 166 Surgical treatment of rhinitis 168 Sinusitis 169 Acute sinusitis 170 Recurrent acute sinusitis 171 Chronic sinusitis 172 Surgery for chronic rhinosinusitis 174 Complications of sinusitis 176 Nasal polyps ...


Sign in / Sign up

Export Citation Format

Share Document