Differential effect of atorvastatin and pravastatin on thoracic spine attenuation: A sub-analysis of a randomized clinical trial.

BACKGROUND: Statins reduce cardiovascular events and may improve bone mineral density. METHODS: We conducted a sub-analysis of a randomized clinical trial that investigated the differential effect of moderate vs intensive low-density lipoprotein cholesterol (LDL-C) lowering therapies on coronary artery calcium (CAC) scores, and used the acquired images to assess the change in radiological attenuation of selected thoracic vertebrae. Baseline and 12-month unenhanced chest CT scans were performed in 420 hyperlipidemic, postmenopausal women randomized to atorvastatin (ATV) 80 mg/day or pravastatin (PRV) 40 mg/day in the Beyond Endorsed Lipid Lowering with Electron Beam Tomography Scanning (BELLES) trial. Bone attenuation was measured in three contiguous thoracic vertebrae at baseline and 12 months. RESULTS: There were no differences in baseline demographic and clinical characteristics between treatment arms. The median percent lowering (interquartile range) in LDL-C was significantly greater with ATV than PRV [-53 (-69 to 20)% vs -28 (-55 to 74)%, p < 0.001], although the CAC score change was similar [12 (-63 to 208)% vs 13 (-75 to 358)%; p = 0.44]. At follow-up, the median bone attenuation loss was significantly greater with PRV than with ATV [-2.6 (-27 to 11)% vs 0 (-11 to 25)%; p < 0.001]. The attenuation loss in the PRV group was comparable to that of a historical untreated general population sample. In the entire cohort, the changes in LDL-C and total cholesterol were inversely correlated with bone attenuation change (p < 0.01). In adjusted multivariable linear regression analyses, race and percent change in LDL-C were independent predictors of bone attenuation change. Age, body mass index, history of smoking, diabetes mellitus, hypertension, peripheral vascular disease, or hormone replacement therapy did not affect percent change in BMD. CONCLUSIONS: These findings support the hypothesis that there is an interaction between bone and cardiometabolic health and that intensive lipid lowering has a beneficial effect on bone health.

PTHrP induces STAT5 activation, secretory differentiation and accelerates mammary tumor development.

BACKGROUND: Parathyroid hormone-related protein (PTHrP) is required for embryonic breast development and has important functions during lactation, when it is produced by alveolar epithelial cells and secreted into the maternal circulation to mobilize skeletal calcium used for milk production. PTHrP is also produced by breast cancers, and GWAS studies suggest that it influences breast cancer risk. However, the exact functions of PTHrP in breast cancer biology remain unsettled. METHODS: We developed a tetracycline-regulated, MMTV (mouse mammary tumor virus)-driven model of PTHrP overexpression in mammary epithelial cells (Tet-PTHrP mice) and bred these mice with the MMTV-PyMT (polyoma middle tumor-antigen) breast cancer model to analyze the impact of PTHrP overexpression on normal mammary gland biology and in breast cancer progression. RESULTS: Overexpression of PTHrP in luminal epithelial cells caused alveolar hyperplasia and secretory differentiation of the mammary epithelium with milk production. This was accompanied by activation of Stat5 and increased expression of E74-like factor-5 (Elf5) as well as a delay in post-lactation involution. In MMTV-PyMT mice, overexpression of PTHrP (Tet-PTHrP;PyMT mice) shortened tumor latency and accelerated tumor growth, ultimately reducing overall survival. Tumors overproducing PTHrP also displayed increased expression of nuclear pSTAT5 and Elf5, increased expression of markers of secretory differentiation and milk constituents, and histologically resembled secretory carcinomas of the breast. Overexpression of PTHrP within cells isolated from tumors, but not PTHrP exogenously added to cell culture media, led to activation of STAT5 and milk protein gene expression. In addition, neither ablating the Type 1 PTH/PTHrP receptor (PTH1R) in epithelial cells nor treating Tet-PTHrP;PyMT mice with an anti-PTH1R antibody prevented secretory differentiation or altered tumor latency. These data suggest that PTHrP acts in a cell-autonomous, intracrine manner. Finally, expression of PTHrP in human breast cancers is associated with expression of genes involved in milk production and STAT5 signaling. CONCLUSIONS: Our study suggests that PTHrP promotes pathways leading to secretory differentiation and proliferation in both normal mammary epithelial cells and in breast tumor cells.

A Comparison between Electron Gamma Shower, National Research Council/Easy Particle Propagation (EGSnrc/Epp) and Monte Carlo N-Particle Transport Code (MCNP) in Simulation of the INTRABEAM ® System with Spherical Applicators.

BACKGROUND: Online Monte Carlo (MC) treatment planning is very crucial to increase the precision of intraoperative radiotherapy (IORT). However, the performance of MC methods depends on the geometries and energies used for the problem under study. OBJECTIVE: This study aimed to compare the performance of MC N-Particle Transport Code version 4c (MCNP4c) and Electron Gamma Shower, National Research Council/easy particle propagation (EGSnrc/Epp) MC codes using similar geometry of an INTRABEAM® system. MATERIAL AND METHODS: This simulation study was done by increasing the number of particles and compared the performance of MCNP4c and EGSnrc/Epp simulations using an INTRABEAM® system with 1.5 and 5 cm diameter spherical applicators. A comparison of these two codes was done using simulation time, statistical uncertainty, and relative depth-dose values obtained after doing the simulation by each MC code. RESULTS: The statistical uncertainties for the MCNP4c and EGSnrc/Epp MC codes were below 2% and 0.5%, respectively. 1e9 particles were simulated in 117.89 hours using MCNP4c but a much greater number of particles (5e10 particles) were simulated in a shorter time of 90.26 hours using EGSnrc/Epp MC code. No significant deviations were found in the calculated relative depth-dose values for both in the presence and absence of an air gap between MCNP4c and EGSnrc/Epp MC codes. Nevertheless, the EGSnrc/Epp MC code was found to be speedier and more efficient to achieve accurate statistical precision than MCNP4c. CONCLUSION: Therefore, in all comparisons criteria used, EGSnrc/Epp MC code is much better than MCNP4c MC code for simulating an INTRABEAM® system.

Calcium-Sensing Receptor Promotes Breast Cancer by Stimulating Intracrine Actions of Parathyroid Hormone-Related Protein.

Parathyroid hormone-related protein (PTHrP) contributes to the development and metastatic progression of breast cancer by promoting hypercalcemia, tumor growth, and osteolytic bone metastases, but it is not known how PTHrP is upregulated in breast tumors. Here we report a central role in this process for the calcium-sensing receptor, CaSR, which enables cellular responses to changes in extracellular calcium, through studies of CaSR-PTHrP interactions in the MMTV-PymT transgenic mouse model of breast cancer and in human breast cancer cells. CaSR activation stimulated PTHrP production by breast cancer cells in vitro and in vivo Tissue-specific disruption of the casr gene in mammary epithelial cells in MMTV-PymT mice reduced tumor PTHrP expression and inhibited tumor cell proliferation and tumor outgrowth. CaSR signaling promoted the proliferation of human breast cancer cell lines and tumor cells cultured from MMTV-PyMT mice. Further, CaSR activation inhibited cell death triggered by high extracellular concentrations of calcium. The actions of the CaSR appeared to be mediated by nuclear actions of PTHrP that decreased p27(kip1) levels and prevented nuclear accumulation of the proapoptotic factor apoptosis inducing factor. Taken together, our findings suggest that CaSR-PTHrP interactions might be a promising target for the development of therapeutic agents to limit tumor cell growth in bone metastases and in other microenvironments in which elevated calcium and/or PTHrP levels contribute to breast cancer progression. Cancer Res; 76(18); 5348-60. ©2016 AACR.

Effect of grain size on ultrasonic softening of pure aluminum.

The objective of this paper is to reveal the main cause of volume effects of ultrasonic vibrations on the plastic behavior of pure aluminum specimens. For this purpose, specimens with different grain sizes were made by ECAP. An experimental tensile test system was designed and made, in which the specimens could be excited by ultrasonic vibrations with a frequency of 20 kHz and amplitude of 5 µm. Five specimens with grain sizes of 109, 38, 15, 7 and 0.97 µm were prepared. Tensile tests of the specimens were performed at room temperature and at constant speed of 0.2 mm/min under static load and superimposed ultrasonic excitations. It was found that ultrasonic vibrations had a remarkable influence on the plastic behavior of pure aluminum and after applying ultrasonic vibrations, flow stress of the all specimens reduced. Reduction of flow stress was dependent on grain size. The specimens with the largest grain size of 109 µm showed a flow stress reduction of 66% while finest grain size of 0.97 µm, a reduction of 11.3% was observed. The result of the current study can help to understand the underlying mechanisms of ultrasonic softening.

EphrinB2 signaling in osteoblasts promotes bone mineralization by preventing apoptosis.

Cells that form bone (osteoblasts) express both ephrinB2 and EphB4, and previous work has shown that pharmacological inhibition of the ephrinB2/EphB4 interaction impairs osteoblast differentiation in vitro and in vivo. The purpose of this study was to determine the role of ephrinB2 signaling in the osteoblast lineage in the process of bone formation. Cultured osteoblasts from mice with osteoblast-specific ablation of ephrinB2 showed delayed expression of osteoblast differentiation markers, a finding that was reproduced by ephrinB2, but not EphB4, RNA interference. Microcomputed tomography, histomorphometry, and mechanical testing of the mice lacking ephrinB2 in osteoblasts revealed a 2-fold delay in bone mineralization, a significant reduction in bone stiffness, and a 50% reduction in osteoblast differentiation induced by anabolic parathyroid hormone (PTH) treatment, compared to littermate sex- and age-matched controls. These defects were associated with significantly lower mRNA levels of late osteoblast differentiation markers and greater levels of osteoblast and osteocyte apoptosis, indicated by TUNEL staining and transmission electron microscopy of bone samples, and a 2-fold increase in annexin V staining and 7-fold increase in caspase 8 activation in cultured ephrinB2 deficient osteoblasts. We conclude that osteoblast differentiation and bone strength are maintained by antiapoptotic actions of ephrinB2 signaling within the osteoblast lineage.

EGFR mutant-specific immunohistochemistry has high specificity and sensitivity for detecting targeted activating EGFR mutations in lung adenocarcinoma.

AIM: We assessed the diagnostic accuracy of epidermal growth factor receptor (EGFR) mutant-specific antibodies for detecting two common activating EGFR mutations. METHODS: Immunohistochemical expression of mutation-specific antibodies against EGFR exon 19 deletion E746-A750 ((c.2235_2249del15 or c.2236_2250del15, p. Glu746_Ala750del) and exon 21 L858R point mutation (c.2573T>G, p.Leu858Arg) were assessed in a cohort of 204 resected early stage node negative lung adenocarcinomas, and protein expression was compared with DNA analysis results from mass spectrometry analysis. RESULTS: Of seven cases with L858R point mutation, six were positive by immunohistochemistry (IHC). There were three false positive cases using L858R IHC (sensitivity 85.7%, specificity 98.5%, positive predictive value 66.7%, negative predictive value 99.5%). All seven E746-A750 exon 19 deletions identified by mutation analysis were positive by IHC. Four additional cases were positive for exon 19 IHC but negative by mutation analysis. The sensitivity of exon 19 IHC for E746-A750 was 100%, specificity 98.0%, positive predictive value 63.6% and negative predictive value 100%. CONCLUSIONS: Mutant-specific EGFR IHC has good specificity and sensitivity for identifying targeted activating EGFR mutations. Although inferior to molecular genetic analysis of the EGFR gene, IHC is highly specific and sensitive for the targeted EGFR mutations. The antibodies are likely to be of clinical value in cases where limited tumour material is available, or in situations where molecular genetic analysis is not readily available.

EphrinB2/EphB4 inhibition in the osteoblast lineage modifies the anabolic response to parathyroid hormone.

Previous reports indicate that ephrinB2 expression by osteoblasts is stimulated by parathyroid hormone (PTH) and its related protein (PTHrP) and that ephrinB2/EphB4 signaling between osteoblasts and osteoclasts stimulates osteoblast differentiation while inhibiting osteoclast differentiation. To determine the role of the ephrinB2/EphB4 interaction in the skeleton, we used a specific inhibitor, soluble EphB4 (sEphB4), in vitro and in vivo. sEphB4 treatment of cultured osteoblasts specifically inhibited EphB4 and ephrinB2 phosphorylation and reduced mRNA levels of late markers of osteoblast/osteocyte differentiation (osteocalcin, dentin matrix protein-1 [DMP-1], sclerostin, matrix-extracellular phosphoglycoprotein [MEPE]), while substantially increasing RANKL. sEphB4 treatment in vivo in the presence and absence of PTH increased osteoblast formation and mRNA levels of early osteoblast markers (Runx2, alkaline phosphatase, Collagen 1α1, and PTH receptor [PTHR1]), but despite a substantial increase in osteoblast numbers, there was no significant change in bone formation rate or in late markers of osteoblast/osteocyte differentiation. Rather, in the presence of PTH, sEphB4 treatment significantly increased osteoclast formation, an effect that prevented the anabolic effect of PTH, causing instead a decrease in trabecular number. This enhancement of osteoclastogenesis by sEphB4 was reproduced in vitro but only in the presence of osteoblasts. These data indicate that ephrinB2/EphB4 signaling within the osteoblast lineage is required for late stages of osteoblast differentiation and, further, restricts the ability of osteoblasts to support osteoclast formation, at least in part by limiting RANKL production. This indicates a key role for the ephrinB2/EphB4 interaction within the osteoblast lineage in osteoblast differentiation and support of osteoclastogenesis.

In vitro investigation of the effect of ambient humidity on regional delivered dose with solution and suspension MDIs.

BACKGROUND: Existing literature has shown that high relative humidity (RH) affects in vitro aerosol drug delivery of nebulizer and pressurized metered dose inhaler (pMDI) formulations. The aim of this study is to investigate in vitro mouth-throat deposition and lung delivery of selected solution and suspension pMDI formulations, under a range of RH, temperature, and flow rate conditions. METHODS: The Alberta Idealized Throat was connected to a collection filter and placed in an environmental control chamber. The formulations selected were beclomethasone dipropionate (BDP) in 13% w/w ethanol/1.3% w/w glycerol and HFA-134a propellant solution ("BDP HFA134a"), BDP in 13% w/w ethanol and HFA-227 propellant solution ("BDP HFA227"), and Flixotide Evohaler (fluticasone propionate 250 µg/dose in HFA-134a suspension). Each of these pMDI formulations was dispersed into the mouth-throat and filter assembly in triplicate, according to an experimental matrix consisting of the following conditions: air flow rates of 28.3, 60, and 90 L/min; 0%, 35%, and 80% RH; operating temperatures of 20°C and 40°C. RESULTS: There was a general increase in mouth-throat deposition and corresponding decrease in filter deposition (representing lung dose fraction), with increasing RH for both BDP HFA134a and Flixotide pMDIs. Increasing temperature from 20°C to 40°C resulted in decreased mouth-throat deposition and increased lung dose fraction for the solution pMDIs, but generally no effect for the suspension pMDI. CONCLUSIONS: Not only is the dose delivery of pMDI formulations affected by environmental conditions (in some cases causing up to 50% reduction in lung delivery), but solution and suspension formulations also behave differently in response to these conditions. These results have implications during dosage form design, testing, and for usage patient use.

Comparison of the Effect of two Denture Cleansers on Tensile bond Strength of a Denture Liner.

STATEMENT OF PROBLEM: One of the most clinical challenging issues in prosthodontics is debonding of soft liners from the denture base. PURPOSE: The aim of this study was to evaluate and compare tensile bond strength between soft liner and heat-cured acrylic resin when immersed in two different types of denture cleanser and distilled water, at different period of times. MATERIALS AND METHOD: In this experimental in vivo study, 238 heat-cured acrylic blocks were made. A soft liner was embedded between the acrylic blocks. Samples were divided into four groups: 17 samples were in the control group and were not soaked in any solution .The remaining samples were divided into 3 groups (Distilled water, Calgon and Fittydent). Each group was then subdivided into two subcategories, regarding the immersion time variable; 15 and 45 minutes. All samples were placed in tension force and tensile bond strength was recorded with the testing machine. One- way ANOVA and Tucky HSD post-hoc test were adopted to analyze the yielded data (α> 0.05). RESULTS: Specimens which were immersed in two denture cleansers (Fittydent and Calgon) and in distilled water showed significant difference (p= 0.001) in bonding strength when compared to the control group. The subjects immersed in denture cleanser solutions and distilled water did not reveal any significant difference (p= 0.90). For all groups; most of the bonding failures (72%) were cohesive type. CONCLUSION: The effect of the denture cleansers and distilled water on the bond strength was not statistically different; however, the difference was significant between the immersed groups with the non-immersed group. Moreover, type of the denture cleanser did not show any effect on the tensile strength. The tensile strength increases with time of immersion.

Serum level of matrix metalloproteinase-3 in patients with oral lichen planus.

BACKGROUND: Oral Lichen planus (OLP) is a chronic lesion of the oral mucosa with unknown origin. Basement membrane changes are common in OLP and may be mediated by proteases such as matrix metalloproteinase (MMPs) and mast cell chymase. The aim of our study was to evaluate the level of serum MMP-3 in OLP com-pared to normal individuals and assess its clinical significance. METHODS: Thirty four serum samples from patients diagnosed with OLP (12 males, 22 females, age: 42.2±10.8 years) and 34 serum samples from healthy control subjects (11 males, 23 females, age: 42.5±13.3 years) were collected and MMP-3 concentration was measured by ELISA. RESULTS: The serum MMP-3 level in OLP patients was higher (21.64±24.31 ng/ml) compared with healthy con-trols (16.52±23.63 ng/ml), but showed no statistically significant difference. A statistically significant difference was demonstrated between the two types of OLP, being more pronounced in the erosive/atrophic form 6). CONCLUSION: The different clinical appearances of OLP are associated with significant differences in MMP-3 serum level.

Effect of pouring time and storage temperature on dimensional stability of casts made from irreversible hydrocolloid.

OBJECTIVE: The aim of this study was to evaluate the dimensional stability of casts made from an alginate impression material poured immediately and stored after specific periods. MATERIALS AND METHODS: The common alginate used in Iran (Super; Iralgin, Golchai Co., Tehran, Iran) was tested. A master model was mounted on a special device and used to obtain the impressions. These impressions were stored at 23°C (SD=1) and 4°C (SD=1) in 100% relative humidity, then poured with gypsum immediately and again after 12, 25, 45 and 60 minutes. The casts were measured with a traveling microscope with the precision of 0.5 micrometer. RESULTS: The dimensional stability of the alginate and impressions were both significantly time and temperature dependent. The impressions were dimensionally stable significantly until 12 minutes of storage at room temperature and until 45 minutes of storage at 4°C (SD=1). CONCLUSION: The dimensional stability of the alginate impressions was influenced by the storage time and environment temperature, but a humid environment and 4°C (SD=1) temperature may delay the pouring.

Premating, not postmating, barriers drive genetic dynamics in experimental hybrid populations of the endangered Sonoran topminnow.

The timing and pattern of reproductive barrier formation in allopatric populations has received much less attention than the accumulation of reproductive barriers in sympatry. The theory of allopatric speciation suggests that reproductive barriers evolve simply as by-products of overall genetic divergence. However, observations of enhanced premating barriers in allopatric populations suggest that sexual selection driven by intraspecific competition for mates may enhance species-specific signals and accelerate the speciation process. In a previous series of laboratory trials, we examined the strength of premating and postmating barriers in an allopatric species pair of the endangered Sonoran topminnow, Poeciliopsis occidentalis and P. sonoriensis. Behavioral observations provided evidence of asymmetrical assortative mating, while reduced brood sizes and male-biased F(1) sex ratios suggest postmating incompatibilities. Here we examine the combined effects of premating and postmating barriers on the genetic makeup of mixed populations, using cytonuclear genotype frequencies of first- and second-generation offspring. Observed genotype frequencies strongly reflect the directional assortative mating observed in behavioral trials, illustrating how isolating barriers that act earlier in the reproductive cycle will have a greater effect on total reproductive isolation and may be more important to speciation than subsequent postmating reproductive barriers.