Effect of Physical Forces on the Metastatic Bone Microenvironment

2013 ◽  
Author(s):  
Joseph L. Sottnik
2017 ◽  
pp. 105-114
Author(s):  
V.P. Nadutyi ◽  
◽  
V.V. Chelyshkina ◽  
S.V. Kostyria ◽  
◽  
...  
Keyword(s):  
Iron Ore ◽  

Author(s):  
J. Richtsmeier ◽  
K.M. Lesciotto

Traditionally, anthropologists study evolutionary change throughmorphological analysis of fossils and comparative primate data. For the analysis of the genotypephenotype continuum, the current emphasis on genes is misplaced because genes don’t make structure. Developmental processes make structure through the activity of cells that use instructions specified by genes. A critical mechanism underlying any phenotypic trait is the genetically guided change in developmental events that produce the trait. But even when a developmental mechanism is identified, the links between genetically guided instructions and phenotypic outcome are lengthy, complicated, flexible, and sensitive to physical forces of functioning organs. We use the study of craniofacial phenotypes of craniosynostosis (premature closure of sutures) to demonstrate how patterns produced by the covariation of cranial traits cannot always reveal mechanism. Next we turn to encephalization, a critical feature of human evolution that covaries with cranial phenotypes, and show how experimental approaches can be used to analyze mechanism underlying this well-documented pattern in human evolution. With the realization that no single line of evidence can explain the dramatic changes in cranial morphology that characterize human evolution come fundamental changes in the way we conduct anthropological inquiry - collaborative efforts from scientists with diverse expertise will continue to push the field forward.


2005 ◽  
Author(s):  
Steven A. Goldstein ◽  
Barbara McCreadie ◽  
Michael Morris

2020 ◽  
Vol 61 (6) ◽  
pp. 188-200
Author(s):  
Malte Schroeder ◽  
Lennart Viezens ◽  
Jördis Sündermann ◽  
Svenja Hettenhausen ◽  
Gerrit Hauenherm ◽  
...  

Introduction: Prostate cancer has a special predilection to form bone metastases. Despite the known impact of the microvascular network on tumour growth and its dependence on the organ-specific microenvironment, the characteristics of the tumour vasculature in bone remain unknown. Methods: The cell lines LNCaP, DU145, and PC3 were implanted into the femurs of NSG mice to examine the microvascular properties of prostate cancer in bone. Tumour growth and the functional and morphological alterations of the microvasculature were analysed for 21 days in vivo using a transparent bone chamber and fluorescence microscopy. Results: Vascular density was significantly lower in tumour-bearing bone than in non-tumour-bearing bone, with a marked loss of small vessels. Accelerated blood flow velocity led to increased volumetric blood flow per vessel, but overall perfusion was not affected. All of the prostate cancer cell lines had similar vascular patterns, with more pronounced alterations in rapidly growing tumours. Despite minor differences between the prostate cancer cell lines associated with individual growth behaviours, the same overall pattern was observed and showed strong similarity to that of tumours growing in soft tissue. Discussion: The increase in blood flow velocity could be a specific characteristic of prostate cancer or the bone microenvironment.


2021 ◽  
Vol 22 (6) ◽  
pp. 2911
Author(s):  
Lauren M. Kreps ◽  
Christina L. Addison

Metastasis to the bone is a common feature of many cancers including those of the breast, prostate, lung, thyroid and kidney. Once tumors metastasize to the bone, they are essentially incurable. Bone metastasis is a complex process involving not only intravasation of tumor cells from the primary tumor into circulation, but extravasation from circulation into the bone where they meet an environment that is generally suppressive of their growth. The bone microenvironment can inhibit the growth of disseminated tumor cells (DTC) by inducing dormancy of the DTC directly and later on following formation of a micrometastatic tumour mass by inhibiting metastatic processes including angiogenesis, bone remodeling and immunosuppressive cell functions. In this review we will highlight some of the mechanisms mediating DTC dormancy and the complex relationships which occur between tumor cells and bone resident cells in the bone metastatic microenvironment. These inter-cellular interactions may be important targets to consider for development of novel effective therapies for the prevention or treatment of bone metastases.


1989 ◽  
Vol 257 (4) ◽  
pp. L179-L189 ◽  
Author(s):  
D. E. Rannels

In many species, partial resection of the lung leads to rapid compensatory growth of the remaining tissue to restore normal lung mass and function. The response to partial pneumonectomy is closely controlled; both its rate and nature are subject to hormonal modulation. Physical factors, particularly distortion of the lung by altered inflation, are likely involved in regulation of the response, although the details of the regulatory mechanisms are not understood. In a number of tissues including the lung, application of external physical force leads to both acute and long-term changes in metabolism. In some cases these include cell growth and division, along with increased production of extracellular matrix components. Similar responses have been described after application of stress to isolated cells in culture. Independent lines of investigation have defined dramatic influences of cell shape on growth, differentiation, and metabolism, but stress-strain relationships at the cellular or subcellular levels are poorly defined. The mechanisms by which changes in cell shape are transduced to intracellular signals likely depend on receptor-mediated interactions with the cytoskeleton, but strain-associated transduction pathways may involve stretch-sensitive ion channels, G protein-dependent reactions, the action of locally produced autocrine or paracrine factors, or a combination of these factors. These observations suggest a general model of the response to pneumonectomy that may be used to formulate specific hypotheses as a basis for future investigations. This approach will provide insight into the mechanisms by which physical forces influence growth and metabolism in the lung and other tissues.


1989 ◽  
Vol 170 ◽  
Author(s):  
Mirta I. Aranguren ◽  
Christopher W. Macosko ◽  
Bima Thakkar ◽  
Matthew Tirrell

AbstractThe study of the type and strength of the filler-polymer linkages is of great importance in understanding the reinforcement of elastomers. Silicone rubbers are weak elastomers and the addition of reinforcing fillers is essential in order to obtain useful, strong materials. The best reinforcing filler for these elastomers are fumed silicas. These fillers, like reinforcing carbon blacks, have very complex structures. Both have fractal characteristics, small particles fused together forming open aggregates that can cluster by physical forces. Silicas have sometimes more complex structures than carbon blacks, but have a better understood surface chemistry. Interactions between polydimethylsiloxanes and silica surfaces have been studied using heat of adsorption measurements of mostly low molecular weight analogs or inferring the strength of the adsorption by the shift of particular peaks in the infrared spectrum [1]. Here we will present a new technique that measures directly the strength of the adsorption of the polymer segments onto glass and between themselves. It also allows for comparison of the strength of such bonds with the strength of a polymer entanglement “link”.


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