Search results for "Bones."
showing 10 items of 276 documents
Effects of physical training on metabolism of connective tissues in young mice.
1980
The effects of physical training on the metabolism of collagen, calcium and glycosaminoglycans in various connective tissues were studied in male NMRI mice. The mice to be trained and their controls were about 3 weeks old (expt. I) and 8 weeks old (expt. II) at the commencement of training. The training was performed on a 5 degree inclined treadmill 5 days a week for 4 weeks in expt. I and for 3 weeks in expt. II. The daily exercise time was progressively increased from 20 min in the first week up to 80 min in the third week. The incorporation of 3H-proline to collagen hydroxyproline was increased by training in long bones, skeletal muscle and Achilles tendon, whereas the incorporation of 3…
Blood circulation of long bones in trained growing rats and mice
1975
The effect of physical training on the blood circulation of long bones was studied in growing rats and mice of NMRI-strain. The animals to be trained and their controls were about 2 weeks old at the beginning of the training. The training took place on a 5 degree inclined treadmill 5 days a week for 3 weeks in experiment I and 7 weeks in experiments II and III. The duration of the daily exercise was progressively increased over 3 weeks. The final exercise bouts were 80 min for moderate and 180 min for intensive training programs. The circulating red cell volume (ml/100 g bone) of the humeral, femoral and tibial bones of the trained animals was lower compared to the controls in all three exp…
Fragility Fractures of the Pelvis.
2017
Fragility fractures of the pelvic ring (FFP) show an increasing frequency. Trauma mechanism, fracture morphology and degree of instability are different from those in high-energy pelvic ring lesions. Little is known about the optimal treatment strategy. A new comprehensive classification system with four categories of increasing instability is presented. It is connected with recommendations for type and invasiveness of treatment. FFP Type I are anterior instabilities only and can be treated conservatively. FFP Type II are non-displaced posterior lesions which can be treated conservatively or with percutaneous fixation. FFP Type III lesions are unilateral displaced posterior lesions which re…
Characterization of C4-2 Prostate Cancer Bone Metastases and Their Response to Castration
2003
New well-characterized preclinical models of prostate cancer (CaP) bone metastases are needed to improve our understanding of the development of CaP-related bone disease in patients. Here we describe characterization of a model consisting of direct injection of C4–2 cells into tibias. Introduction: Prostate cancer (CaP) has a high proclivity to metastasize to bone. Development and characterization of preclinical models of CaP bone metastases are of high interest. The objective of this study was to characterize C4–2 bone metastases and their response to castration. Materials and Methods: Cell suspensions of C4-2, a subline of LNCaP, were injected directly into the tibias of intact male mice.…
Is there a role for percutaneous pelvic and acetabular reconstruction?
2007
The primary goal in the treatment of pelvic fractures is the restoration of haemodynamic stability. The secondary goal is the reconstruction of stability and symmetry of the pelvic ring. Percutaneous reconstruction can only be accepted if these goals are met. The type of definitive surgery is dependent of the degree of instability of the anterior and posterior pelvic ring. Retrograde transpubic screw fixation of pubic rami fractures is a good alternative to external fixation or plate and screw osteosynthesis. The technique of screw placement and image intensifier control is explained. Internal fixation of pure sacroiliac dislocations, fracture-dislocations of the sacroiliac joint and sacral…
Photo-acoustic excitation and optical detection of fundamental flexural guided wave in coated bone phantoms.
2013
Abstract Photo-acoustic (PA) imaging was combined with skeletal quantitative ultrasound (QUS) for assessment of human long bones. This approach permitted low-frequency excitation and detection of ultrasound so as to efficiently receive the thickness-sensitive fundamental flexural guided wave (FFGW) through a coating of soft tissue. The method was tested on seven axisymmetric bone phantoms, whose 1- to 5-mm wall thickness and 16-mm diameter mimicked those of the human radius. Phantoms were made of a composite material and coated with a 2.5- to 7.5-mm layer of soft material that mimicked soft tissue. Ultrasound was excited with a pulsed Nd:YAG laser at 1064-nm wavelength and received on the s…
Thickness sensitivity of ultrasound velocity in long bone phantoms
2004
One approach to bone disease diagnosis such as osteoporosis is to measure the velocity of ultrasound propagating axially along long bones. In this study, the variation in velocity as a function of radial position was assessed using two polyvinyl chloride (PVC) bone phantoms with cross-sectional geometry similar to the human tibia but differing in medullary cavity diameter. Two ultrasonometers were used: these were a commercial device operating at a relatively high frequency (HF) of 1.25 MHz and a prototype low frequency (LF) device operating at approximately 200 kHz. The LF measurements showed a larger variation with radial position, with changes in velocity of up to 20% occurring around th…
Measuring guided waves in long bones: Modeling and experiments in free and immersed plates
2005
Guided waves, consistent with the A0 Lamb mode, have previously been observed in bone phantoms and human long bones. Reported velocity measurements relied on line fitting of the observed wave fronts. Such an approach has limited ability to assess dispersion and is affected by interference by other wave modes. For a more robust identification of modes and determination of phase velocities, signal processing techniques using the fast Fourier transform (FFT) were investigated. The limitations of FFT because of spatial resolution were addressed to improve the precision of the measured modes. An inversion scheme was developed for determining the plate thickness from the measured velocity. Experi…
Coded excitation speeds up the detection of the fundamental flexural guided wave in coated tubes
2016
The fundamental flexural guided wave (FFGW) permits ultrasonic assessment of the wall thickness of solid waveguides, such as tubes or, e.g., long cortical bones. Recently, an optical non-contact method was proposed for ultrasound excitation and detection with the aim of facilitating the FFGW reception by suppressing the interfering modes from the soft coating. This technique suffers from low SNR and requires iterative physical scanning across the source-receiver distance for 2D-FFT analysis. This means that SNR improvement achieved by temporal averaging becomes time-consuming (several minutes) which reduces the applicability of the technique, especially in time-critical applications such as…
The rapid anastomosis between prevascularized networks on silk fibroin scaffolds generated in vitro with cocultures of human microvascular endothelia…
2010
The survival and functioning of a bone biomaterial upon implantation requires a rapidly forming and stably functioning vascularization that connects the implant to the recipient. We have previously shown that human microcapillary endothelial cells (HDMEC) and primary human osteoblast cells (HOS) in coculture on various 3-D bone biomaterial scaffolds rapidly distribute and self-assemble into a morphological structure resembling bone tissue. Endothelial cells form microcapillary-like structures containing a lumen and these were intertwined between the osteoblast cells and the biomaterial. This tissue-like self-assembly occurred in the absence of exogenously added angiogenic stimuli or artific…