The microenvironment matters: estrogen deficiency fuels cancer bone metastases

Factors released during osteoclastic bone resorption enhance disseminated breast cancer cell progression by stimulating invasiveness, growth, and a bone-resorptive phenotype in cancer cells. Postmenopausal bone loss may accelerate progression of breast cancer growth in bone, explaining the anticancer benefit of the bone-specific antiresorptive agent zoledronic acid in the postmenopausal setting. Clin Cancer Res; 20(11); 2817-9. ©2014 AACR

Unitary transformations for testing Bell inequalities

It is shown that optical experimental tests of Bell inequality violations can be described by SU(1,1) transformations of the vacuum state, followed by photon coincidence detections. The set of all possible tests are described by various SU(1,1) subgroups of Sp(8,$\Bbb R$). In addition to establishing a common formalism for physically distinct Bell inequality tests, the similarities and differences of post--selected tests of Bell inequality violations are also made clear. A consequence of this analysis is that Bell inequality tests are performed on a very general version of SU(1,1) coherent states, and the theoretical violation of the Bell inequality by coincidence detection is calculated and discussed. This group theoretical approach to Bell states is relevant to Bell state measurements, which are performed, for example, in quantum teleportation.Comment: 3 figure

Mechanisms of Ar release from Himalayan metamorphic hornblende

Changes in hornblende samples that occur during stepwise 39Ar/40Ar analysis were studied experimentally and mineralogically. A complex succession of reactions was seen (hornblende ~ oxyhornblende ~ clinopyroxene-structured phase ~ fine-grained reaction products ~ glasses) in the temperature range 750-1300 °C. The release of Ar from hornblende in the vacuum furnace appeared to occur by fundamentally different processes from those resulting in Ar loss during metamorphism. Simple diffusional interpretations of the release patterns are, therefore, not capable of revealing the thermal history of samples. In principle, some useful information may be obtained if long-standing fractures andother defects control both natural Ar loss and mineral reactions within the laboratory

Cancer-associated osteoclast differentiation takes a good look in the miR(NA)ror

Tumor-bone cell interactions are critical for the development of metastasis-related osteolytic bone destruction. In this issue of Cancer Cell, Ell and colleagues show how a discrete miRNA network regulates osteoclastogenesis during breast cancer bone metastasis. A signature of upregulated miRNAs may have diagnostic and therapeutic implications for bone metastases

Skeletal muscle Ca2+ mishandling: another effect of bone-to-muscle signaling

Our appreciation of crosstalk between muscle and bone has recently expanded beyond mechanical force-driven events to encompass a variety of signaling factors originating in one tissue and communicating to the other. While the recent identification of new ‘myokines’ has shifted some focus to the role of muscle in this partnership, bone-derived factors and their effects on skeletal muscle should not be overlooked. This review summarizes some previously known mediators of bone-to-muscle signaling and also recent work identifying a new role for bone-derived TGF-β as a cause of skeletal muscle weakness in the setting of cancer-induced bone destruction. Oxidation of the ryanodine receptor/calcium release channel (RyR1) in skeletal muscle occurs via a TGF-β-Nox4-RyR1 axis and leads to calcium mishandling and decreased muscle function. Multiple points of potential therapeutic intervention were identified, from preventing the bone destruction to stabilizing the RYR1 calcium channel. This new data reinforces the concept that bone can be an important source of signaling factors in pathphysiological settings

STRESS SENSITIVITY OF MERCURY INJECTION MEASUREMENTS

Many petrophysical properties (e.g. permeability, electrical resistivity etc.) of tight rocks are very stress sensitive. However, most mercury injection measurements are made using an instrument that does not apply a confining pressure to the samples. Here we further explore the implications of the use and analysis of data from mercury injection porosimetry or mercury capillary pressure measurements (MICP). Two particular aspects will be discussed. First, the effective stress acting on samples analysed using standard MICP instruments (i.e. Micromeritics Autopore system) is described. Second, results are presented from a new mercury injection porosimeter that is capable of injecting mercury at up to 60,000 psi into 1.5 or 1 in core plugs while keeping a constant net stress up to 15,000 psi. This new instrument allows monitoring of the electrical conductivity across the core during the test so that an accurate threshold pressure can be determined. Although no external confining pressure is applied (unconfined) when using the standard MICP instrument, this doesn’t mean that the measurements can be considered as unstressed. Instead, the sample is under isostatic compression by the mercury until it enters the pore space of the sample. As an approximation, the stress that the mercury places on the sample is equal to its threshold pressure. Thus, the permeability calculated from standard MICP data is equivalent to that measured at its threshold pressure. Not all the samples have the same stress dependency thus comparing measured permeabilities at a single stress with values calculated from standard MICP data, corresponding at different threshold pressures, can lead to erroneous correlations. Therefore, the estimation of permeabilities from standard MICP data can be flawed and uncertain unless the stress effect is included. Results obtained from the new mercury injection system, porosimeter under net stress, are radically different from those obtained from standard MICP instruments such as the Autopore IV. In particular, the measurements at reservoir conditions produce threshold pressures that are three times higher and pore throat sizes that are 1/3rd of those measured by the standard MICP instrument. The results clearly indicate that calculating capillary height functions, sealing capacity, etc. from the standard instrument can lead to large errors that can have significant impact on subsurface characterization

The Role of TGFβ in Bone-Muscle Crosstalk

Purpose of Review The role of bone-derived factors in regulation of skeletal muscle function is an important emerging aspect of research into bone-muscle crosstalk. Implications for this area of research are far reaching and include understanding skeletal muscle weakness in cancer, osteoporosis, cachexia, rare diseases of bone, and aging. Recent Findings Recent research shows that bone-derived factors can lead to changes in the skeletal muscle. These changes can either be anabolic or catabolic, and we focus this review on the role of TGFβ in driving oxidative stress and skeletal muscle weakness in the setting of osteolytic cancer in the bone. Summary The bone is a preferred site for breast cancer metastasis and leads to pathological bone loss. Osteolytic cancer in the bone leads to release of TGFβ from the bone via osteoclast-mediated bone destruction. Our appreciation of crosstalk between the muscle and bone has recently expanded beyond mechanical force-driven events to encompass a variety of signaling factors originating in one tissue and communicating to the other. This review summarizes some previously known mediators of bone-to-muscle signaling and also recent work identifying a new role for bone-derived TGFβ as a cause of skeletal muscle weakness in the setting of osteolytic cancer in the bone. Multiple points of potential therapeutic intervention are discussed

Lost and found: the radial quantum number of Laguerre-Gauss modes

We introduce an operator linked with the radial index in the Laguerre-Gauss modes of a two-dimensional harmonic oscillator in cylindrical coordinates. We discuss ladder operators for this variable, and confirm that they obey the commutation relations of the su(1,1) algebra. Using this fact, we examine how basic quantum optical concepts can be recast in terms of radial modes.Comment: Some minor typos fixed

Alkaline phosphatase in metastatic castration-resistant prostate cancer: reassessment of an older biomarker

Since most patients with metastatic castration-resistant prostate cancer (mCRPC) have bone metastases, it is important to understand the potential impact of therapies on prognostic biomarkers, such as ALP. Clinical studies involving mCRPC life-prolonging agents (i.e., sipuleucel-T, abiraterone, enzalutamide, docetaxel, cabazitaxel, and radium-223) have shown that baseline ALP level is prognostic for overall survival, and may be a better prognostic marker for overall survival than prostate-specific antigen in patients with bone-dominant mCRPC. Mechanism of action differences between therapies may partly explain ALP dynamics during treatment. ALP changes can be interpreted within the context of other parameters while monitoring disease activity to better understand the underlying pathology. This review evaluates the current role of ALP in mCRPC