1998 William J. Stickel Gold Award. The effects of extrinsic muscle forces on the forefoot-to-rearfoot loading relationship in vitro. Tibia and Achilles tendon

1998 ◽  
Vol 88 (10) ◽  
pp. 471-482 ◽  
Author(s):  
ED Ward ◽  
RD Phillips ◽  
PE Patterson ◽  
GJ Werkhoven
Keyword(s):  
Achilles Tendon ◽  
Gait Cycle ◽  
Axial Loading ◽  
Muscular Activity ◽  
Linear Increase ◽  
Muscle Forces ◽  
Limited Data ◽  
Loading System ◽  
Inclination Angles

The effects of muscular activity on the distribution of forces under the foot, as well as within the foot, are of great importance for determining the mechanisms of foot pathologies. Limited data exist concerning muscle forces during the gait cycle and the effects of muscle forces conveyed to the ground-reactive forces of the foot. The authors developed a cadaveric loading system to determine the effects of force applied to the Achilles tendon on the forefoot-to-rearfoot loading relationship in eight cadaveric specimens. The study indicated that, during axial loading of the tibia, force was inherently transferred from the rearfoot to the forefoot. However, the observed forefoot-to-rearfoot loading relationship did not match the predicted loading relationship from a rigid-body diagram, as would be observed in a class I lever. The results indicated that, as the force was increased on the Achilles tendon, the change in loads on the forefoot and rearfoot was not linear. Specimens with calcaneal inclination angles greater than 20 degrees demonstrated a more linear increase as compared with those with inclination angles less than 20 degrees.

Biomechanical properties of different techniques used in vitro for suturing mid-substance Achilles tendon ruptures

2017 ◽  
Vol 50 ◽  
pp. 78-83 ◽  
Author(s):  
Carlos De la Fuente ◽  
Carlos Cruz-Montecinos ◽  
Helen L. Schimidt ◽  
Hugo Henríquez ◽  
Sebastián Ruidiaz ◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Biomechanical Properties ◽  
Tendon Ruptures

Age-dependent changes in volume and haemoglobin content of erythrocytes in the carp (Cyprinus carpio L.)

1989 ◽  
Vol 141 (1) ◽  
pp. 133-149 ◽  
Author(s):  
W. Speckner ◽  
J. F. Schindler ◽  
C. Albers
Keyword(s):  
Gel Filtration ◽  
Linear Increase ◽  
Human Erythrocytes ◽  
Main Peak ◽  
Red Cell ◽  
Human Haemoglobin ◽  
Cell Fractions ◽  
Haemoglobin Content

Carp erythrocytes were fractionated by angle-head centrifugation which yielded fractions with a linear increase in density. Haematological examinations revealed that the heavier red blood cells of carp had greater volumes (MCV), more haemoglobin (MCH) and higher haemoglobin concentrations (MCHC) than light ones. The same experiments with human red cell fractions yielded a decrease in MCV, constant MCH and an increase in MCHC. Haemoglobin content in individual erythrocytes was also determined by scanning stage absorbance cytophotometry to establish the frequency distribution of the cellular haemoglobin contents. In carp, the distribution was symmetrical with the means increasing with density. No such change with cell density was found in human erythrocytes. Both carp and human erythrocytes incorporated [2-14C]glycine in vitro. After gel filtration, radioactivity was detected in carp, but not in human, haemoglobin fractions. 14C was found in all three haemoglobin fractions, obtained by isoelectric focusing, and was present in the haem and in the globin. [2-14C]glycine-labelled erythrocytes were reinjected into chronically cannulated carp and followed in vivo for several months. With time, the main peak of scintillation counts shifted from red cell fractions of low to high density. This is considered as evidence that density and age of red cells in carp are positively correlated and that erythrocytes can synthesize haemoglobin while circulating in the peripheral blood.

In vitro effectiveness of biapenem against IMP-producing Enterobacteriaceae

2021 ◽  
Vol 70 (10) ◽  
Author(s):  
Kazuyoshi Gotoh ◽  
Makoto Miyoshi ◽  
I Putu Bayu Mayura ◽  
Koji Iio ◽  
Osamu Matsushita ◽  
...  
Keyword(s):  
Therapeutic Option ◽  
Small Data ◽  
Limited Data ◽  
Data Set ◽  
Content Type ◽  
Link Type ◽  
Almost All ◽  
New Treatments ◽  
Time Kill

The options available for treating infections with carbapenemase-producing Enterobacteriaceae (CPE) are limited; with the increasing threat of these infections, new treatments are urgently needed. Biapenem (BIPM) is a carbapenem, and limited data confirming its in vitro killing effect against CPE are available. In this study, we examined the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of BIPM for 14 IMP-1-producing Enterobacteriaceae strains isolated from the Okayama region in Japan. The MICs against almost all the isolates were lower than 0.5 µg ml−1, indicating susceptibility to BIPM, while approximately half of the isolates were confirmed to be bacteriostatic to BIPM. However, initial killing to a 99.9 % reduction was observed in seven out of eight strains in a time–kill assay. Despite the small data set, we concluded that the in vitro efficacy of BIPM suggests that the drug could be a new therapeutic option against infection with IMP-producing CPE.

scholarly journals Are In Vitro Susceptibilities to Azole Antifungals Predictive of Clinical Outcome in the Treatment of Candidemia?

2018 ◽  
Vol 56 (12) ◽  
Author(s):  
Twisha S. Patel ◽  
Peggy L. Carver ◽  
Gregory A. Eschenauer
Keyword(s):  
Invasive Candidiasis ◽  
Randomized Trials ◽  
Published Data ◽  
Murine Models ◽  
Limited Data ◽  
Content Type ◽  
Clinical Breakpoints ◽  
The Impact ◽  
The Relationship

ABSTRACT The purpose of this review is to critically analyze published data evaluating the impact of azole pharmacokinetic and pharmacodynamic parameters, MICs, and Candida species on clinical outcomes in patients with candidemia. Clinical breakpoints (CBPs) for fluconazole and voriconazole, which are used to determine susceptibility, have been defined by the Clinical and Laboratory Standards Institute (CLSI) for Candida species. Studies evaluating the relationship between treatment efficacy and in vitro susceptibility, as well as the pharmacodynamic targets, have been conducted in patients treated with fluconazole for candidemia; however, for species other than Candida albicans and Candida glabrata, and for other forms of invasive candidiasis, data remain limited and randomized trials are not available. Limited data evaluating these relationships with voriconazole are available. While pharmacodynamic targets for posaconazole and isavuconazole have been proposed based upon studies conducted in murine models, CBPs have not been established by CLSI. Fluconazole remains an important antifungal agent for the treatment of candidemia, and data supporting its use based on in vitro susceptibility are growing, particularly for C. albicans and C. glabrata. Further investigation is needed to establish the roles of voriconazole, posaconazole, and isavuconazole in the treatment of candidemia and for all agents in the treatment of other forms of invasive candidiasis.

scholarly journals A Novel Kartogenin-Releasing Polymer Scaffold Promotes Wounded Rat Achilles Tendon Enthesis Healing

2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0053
Author(s):  
Jianying Zhang ◽  
Daibang Nie ◽  
Guangyi Zhao ◽  
Susheng Tan ◽  
MaCalus Hogan ◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Saline Group ◽  
Future Research ◽  
Dependent Manner ◽  
Polymer Scaffold ◽  
Normal Medium ◽  
Post Surgery ◽  
Tendon Stem Cells

Category: Hindfoot Introduction/Purpose: Entheses have a special fibrocartilage transition zone where tendons and ligaments attach to bone. Enthesis injury is very common, and the reattachment of tendon to bone is a great challenge because healing takes place between a soft tissue (tendon) and a hard tissue (bone). We have now developed a kartogene (KGN)-containing polymer scaffold (KGN-P) that can precisely deliver KGN to damaged enthesis area. The effects of the KGN-containing polymer on the healing of wounded TBJ were investigated in vitro and in vivo. Methods: The proliferation and chondrogenesis of rat Achilles tendon stem cells (TSCs) grown in four conditions were measured: normal medium (Control); normal medium with 100 nM KGN (KGN); lysine diisocyanate (LDI)-glycerol scaffold with normal medium (LDI-P); LDI-glycerol-KGN scaffold with normal medium (KGN-P).A wound (1 mm) was created on each hind leg Achilles enthesis of all 8 rats (3 months old). The wounds were then treated either with 10 ul saline (Wound); or 10 ul of 10 uM KGN (KGN); or LDI polymer scaffold (LDI-P); or KGN-containing polymer scaffold (KGN-P). The rats were sacrificed on day 15 and 30 post-surgery, and their Achilles entheses were collected for gross inspection and histochemical analysis. Results: KGN-containing polymers have sponge-like structures (Fig. 1A-D), and release KGN in a time- and temperature-dependent manner (Fig. 1E). KGN-P scaffold induced chondrogenesis of TSCs (Fig. 2D, 2H) without changing cell proliferation (Fig. 2I), and enhanced fibrocartilage-like tissue formation (Fig. 3E). KGN (Fig. 3C) and LDI-P (Fig. 3D) treated groups exhibited unhealed wound areas as in saline group (Fig. 3B). Finally, KGN-P and KGN treated rat TSCs underwent chondrogenesis by upregulating collagen II, aggrecan, and SOX-9 expression (Fig. 3F). Conclusion: Our results showed that KGN-containing polymer scaffold enhanced wounded enthesis healing by inducing TSC chondrogenesis and promoting the formation of the fibrocartilage in the wound site. The KGN-P may be used for regeneration of wounded entheses in clinical settings. Future research will focus on optimizing KGN concentration and releasing rate in the polymer scaffold during enthesis healing.

AN ALGORITHM TO CALCULATE THE COMPONENTS OF ALL MUSCLE FORCES DURING EACH PHASES OF THE GAIT CYCLE, FOR THE PELVIC-FEMUR COMPLEX

2005 ◽  
Vol 05 (04) ◽  
pp. 539-548 ◽  
Author(s):  
SANTANU MAJUMDER ◽  
AMIT ROYCHOWDHURY ◽  
SUBRATA PAL
Keyword(s):  
Finite Element ◽  
Hip Joint ◽  
Computational Models ◽  
Gait Cycle ◽  
Muscle Force ◽  
Fe Analysis ◽  
Muscle Forces ◽  
Force Magnitude ◽  
Flexion Extension ◽  
Force Components

With the help of finite element (FE) computational models of femur, pelvis or hip joint to perform quasi-static stress analysis during the entire gait cycle, muscle force components (X, Y, Z) acting on the hip joint and pelvis are to be known. Most of the investigators have presented only the net muscle force magnitude during gait. However, for the FE software, either muscle force components (X, Y, Z) or three angles for the muscle line of action are required as input. No published algorithm (with flowchart) is readily available to calculate the required muscle force components for FE analysis. As the femur rotates about the hip center during gait, the lines of action for 27 muscle forces are also variable. To find out the variable lines of action and muscle force components (X, Y, Z) with directions, an algorithm was developed and presented here with detailed flowchart. We considered the varying angles of adduction/abduction, flexion/extension during gait. This computer program, obtainable from the first author, is able to calculate the muscle force components (X, Y, Z) as output, if the net magnitude of muscle force, hip joint orientations during gait and muscle origin and insertion coordinates are provided as input.

BIOMECHANICAL MODEL PREDICTING VALUES OF MUSCLE FORCES IN THE SHOULDER GIRDLE DURING ARM ELEVATION

2010 ◽  
Vol 10 (04) ◽  
pp. 643-666 ◽  
Author(s):  
ERIC BERTHONNAUD ◽  
MELISSA MORROW ◽  
GUILLAUME HERZBERG ◽  
KAI-NAN AN ◽  
JOANNES DIMNET
Keyword(s):  
Geometric Modeling ◽  
Geometric Model ◽  
Contractile Element ◽  
Muscle Forces ◽  
Active Muscle ◽  
Cross Sectional ◽  
Shoulder Complex ◽  
Arm Elevation

A three-dimensional (3D) geometric model for predicting muscle forces in the shoulder complex is proposed. The model was applied throughout the range of arm elevation in the scapular plan. In vitro testing has been performed on 13 cadaveric shoulders. The objectives were to determine homogeneous values of physiological parameters of shoulder muscles and to locate sites of muscular attachment to any bone of the shoulder complex. Muscular fiber lengths, lengths of contractile element (CE), and muscle volumes were measured, corresponding physiological cross-sectional area (PCSA) were calculated, and force/length muscle relations were found. An in vivo biplanar radiography was performed on five volunteers. The photogrammetric reconstruction of bone axes and landmarks were coupled with a geometric modeling of bones and muscle sites of attachment. Muscular paths were drawn and changes in lengths during movement have been estimated. Directions of muscle forces are the same as that of muscular path at the point of attachment to bone. Magnitudes of muscular forces were found from muscle lengths coupled with force/length relations. Passive forces were directly determined contrary to active muscle forces. A resulting active muscle force is calculated from balancing weight and passive forces at each articular center. Active muscle forces were calculated by distributing the resulting force among active muscles based on the muscular PCSA values.

scholarly journals Radial shock waves effectively introduced NF-kappa B decoy into rat achilles tendon cells in vitro

2010 ◽  
Vol 28 (8) ◽  
pp. 1078-1083 ◽  
Author(s):  
Kaori Sugioka ◽  
Koichi Nakagawa ◽  
Ryo Murata ◽  
Nobuyasu Ochiai ◽  
Takahisa Sasho ◽  
...  
Keyword(s):  
Shock Waves ◽  
Achilles Tendon ◽  
Nf Kappa B ◽  
Tendon Cells
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