The evaluation of the osteopromoting capabilities of composites based on biopolymers and gold/silver nanoparticles doped bioactive glasses on an experimental rat bone defect.

The most important concept behind using bone scaffolds is the biocompatibility of the material to avoid a local inflammatory response and must have the following properties: osteoinduction, osteoconductivity, angiogenesis, and mechanical support for cell growth. Gold nanoparticles/gold and silver nanoparticles -containing bioactive glasses in biopolymer composites have been used to enhance bone regeneration. These composites were testedin vitroon fibroblast and osteoblast cell lines using MTT tests, immunofluorescence, scanning electron microscopy analysis, andin vivoin an experimental bone defect in Sprague-Dawley rats. Both composites promoted adequate biological effects on human fibroblastic BJ (CRL 2522TM) cell lines and human osteoblastic cells isolated from the human patella in terms of cell proliferation, morphology, migration, and attachment. Most importantly, they did not cause cellular apoptosis and necrosis. According to the histological and immunohistochemical results, both composites were osteoinductive and promoted new bone formation at 60 d. Evidence from this study suggests that the small amount of silver content does not influence negatively thein vitroorin vivoresults. In addition, we obtained accurate results proving that the existence of apatite layer and proteins on the surface of the recovered composite, supports the validity ofin vitrobioactivity research.

Bioactive glass-biopolymers­gold nanoparticle based composites for tissue engineering applications.

Biomaterials based on bioactive glass with gold nanoparticle composites have many applications in tissue engineering due to their tissue regeneration and angiogenesis capacities. The objectives of the study were to develop new composites using bioactive glass with gold nanospheres (BGAuSP) and gold nanocages (BGAuIND), individually introduced in alginate-pullulan (Alg-Pll) polymer, to evaluate their biocompatibility potential, and to compare the obtained results with those achieved when ß-tricalcium phosphate-hydroxyapatite (ßTCP/HA) replaced the BG. The novel composites underwent structural and morphological characterization followed by in vitro viability testing on fibroblast and osteoblast cell lines. Additionally, the biomaterials were subcutaneously implanted in Sprague Dawley rats, for in vivo biocompatibility assessment during 3 separate time frames (14, 30 and 60 days). The biological effects were evaluated by histopathology and immunohistochemistry. The physical characterization revealed the cross-linking between polymers and glasses/ceramics and demonstrated a suitable thermal stability for sterilization processes. The in vitro assays demonstrated adequate form, pore size of composites ranging from few micrometers up to 100 µm, while the self-assembled apatite layer formed after simulated body fluid immersion confirmed the composites' bioactivity. Viability assays have highlighted optimal cellular proliferation and in vitro biocompatibility for all tested composites. Furthermore, based on the in vivo subcutaneous analyses the polymer composites with BGAuNP have shown excellent biocompatibility at 14, 30 and 60 days, exhibiting marked angiogenesis while, tissue proliferation was confirmed by high number of Vimentin positive cells, in comparison with the polymer composite that contains ßTCP/HA, which induced an inflammatory response represented by a foreign body reaction. The obtained results suggest promising, innovative, and biocompatible composites with bioactive properties for future soft tissue and bone engineering endeavours.

Short- and long-term outcomes of coronary stenting in women versus men: results from the National Cardiovascular Data Registry Centers for Medicare & Medicaid services cohort.

BACKGROUND: Conflicting evidence exists on sex-based outcomes after coronary stenting. METHODS AND RESULTS: Data on 426 996 patients ≥65 years old (42.3% women) from the National Cardiovascular Data Registry CathPCI Registry (2004-2008) were linked to Medicare inpatient claims to compare in-hospital outcomes by sex and long-term outcomes by sex and stent type. In-hospital complications were more frequent in women than in men: death (3869 [2.2%] versus 3737 [1.6%]; adjusted odds ratio, 1.41; 95% confidence interval [CI], 1.33-1.49), myocardial infarction (2365 [1.3%] versus 2858 [1.2%]; odds ratio, 1.19; 95% CI, 1.11-1.27), bleeding (7860 [4.4%] versus 5627 [2.3%]; odds ratio, 1.86; 95% CI, 1.79-1.93), and vascular complications (2381 [1.3%] versus 1648 [0.7%]; odds ratio, 1.85; 95% CI, 1.73-1.99). At 20.4 months, women had a lower adjusted risk of death (hazard ratio [HR], 0.92; 95% CI, 0.90-0.94) but similar rates of myocardial infarction, revascularization, and bleeding. Relative to bare metal stent use, drug-eluting stent use was associated with similar improved long-term outcomes in both sexes: death (women: adjusted HR, 0.78; 95% CI, 0.76-0.81; men: HR, 0.77; 95% CI, 0.74-0.79), myocardial infarction (women: HR, 0.79; 95% CI, 0.74-0.84; men: HR, 0.81; 95% CI, 0.77-0.85), and revascularization (women: HR, 0.93; 95% CI, 0.90-0.97; men: HR, 0.91; 95% CI, 0.88-0.94). There was no interaction between sex and stent type for long-term outcomes. CONCLUSIONS: In contemporary coronary stenting, women have a slightly higher procedural risk than men but have better long-term survival. In both sexes, use of a drug-eluting stent is associated with lower long-term likelihood for death, myocardial infarction, and revascularization.

Expression of p53, Bcl-2, VEGF, Ki67 and PCNA and prognostic significance in hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma is one of the most common malignant tumors that carry a poor prognosis. To improve the long-term outlook for HCC, an accurate prognosis is important. AIMS: To study the immunohistochemical expressions of p53, Ki67, Bcl-2, VEGF and PCNA and their potential role as prognostic factors in patients with radical resection of hepatocellular carcinoma. PATIENTS AND METHODS: Forty-seven formalin-fixed paraffin-embedded tumor samples from patients with HCC receiving liver resection were investigated immunohistochemically for the expression of cellular proliferation markers PCNA, Ki67, p53, Bcl-2 and VEGF and their correlation with tumor characteristics and survival time after resection. RESULTS: p53 was expressed in a higher percentage (85.7 vs. 42.1%) in undifferentiated histological tumor grades (Edmondson Steiner G3/G4 vs. G1/G2). Patients with p53 accumulating tumors showed a worse survival than patients with p53 non-accumulating tumors (median 9.5 vs. 16.5 months). Over-expression of VEGF was found in 38.3% of all HCCs. VEGF expression was significantly correlated with p53 expression and recurrence rates. The results showed that the labeling index of PCNA and expression of p53 are correlated. The high labeling index of PCNA or over-expression of p53 resulted in high risk of tumor recurrence, more aggressive growth and poor survival. CONCLUSION: High labeling index of PCNA, p53 nuclear accumulation and VEGF high expression are associated with poor survival in patients with HCC.

[Experimental left orthotopic mono-pulmonary transplantation swine model]. / Model experimental porcin de transplant mono-pulmonar stâng ortotopic.

UNLABELLED: The swine model is an orthotopic pulmonary transplantation model often uses in the transplantation experiments. The purpose of this study is to control the transplantation technique on swine model and perform the learning curve of this procedure, as much from surgical than anaesthetic point of view. METHODS: 20 orthotopic left pulmonary transplantations were performed on 20 pairs of domestic female pigs, weighting 30-35 kg. Tracheal intubation's time, monitoring time, bronchial, arterial and venous anastomosis time, warm ischemia time, were recorded. The causes of morbidity and mortality were also analyzed. RESULTS: Bronchial anastomosis was a running mattress suture. All bronchial anastomoses were airtight. Arterial anastomosis was a running mattress end-to-end anastomosis. The venous return was carried out by a left atrium-venous running mattress suture anastomosis. Satisfied blood flows in all arterial and venous anastomoses were obtained. CONCLUSIONS: We established an experimental swine model of pulmonary transplantation. The anaesthetic and surgical team performed their learning curve. Various anastomoses times and consequently, the total time of the intervention, were shortened.

In vivo magnetic resonance detects rapid remodeling changes in the topology of the trabecular bone network after menopause and the protective effect of estradiol.

INTRODUCTION: Estrogen depletion after menopause is accompanied by bone loss and architectural deterioration of trabecular bone. The hypothesis underlying this work is that the microMRI-based virtual bone biopsy can capture the temporal changes of scale and topology of the trabecular network and that estrogen supplementation preserves the integrity of the trabecular network. MATERIALS AND METHODS: Subjects studied were early postmenopausal women, 45-55 yr of age (N = 65), of whom 32 were on estrogen (estradiol group), and the remainder were not (control group). Early menopause was defined by amenorrhea for 6-24 mo and elevated serum follicle-stimulating hormone (FSH) concentration. The subjects were evaluated with three imaging modalities at baseline and 12 and 24 mo to determine the temporal changes in trabecular and cortical architecture and density. microMRI of the distal radius and tibia was performed at 137 x 137 x 410-microm(3) voxel size. The resulting bone volume fraction maps were Fourier interpolated to a final voxel size of 45.7 x 45.7 x 136.7 microm(3), binarized, skeletonized, and subjected to 3D digital topological analysis (DTA). Skeletonization converts trabecular rods to curves and plates to surfaces. Parameters quantifying scale included BV/TV, whereas DTA parameters included the volume densities of curves (C) and surface (S)-type voxels, as well as composite parameters: the surface/curve ratio (S/C), and erosion index (EI, ratio of the sum of parameters expected to increase with osteoclastic resorption divided by the sum of those expected to decrease). For comparison, pQCT of the same peripheral locations was conducted, and trabecular density and cortical structural parameters were measured. Areal BMD of the lumbar vertebrae and hip was also measured. RESULTS: Substantial changes in trabecular architecture of the distal tibia, in particular as they relate to topology of the network, were detected after 12 mo in the control group. S/C decreased 5.6% (p < 0.0005), and EI increased 7.1% (p < 0.0005). Most curve- and profile-type voxels (representative of trabecular struts), increased significantly (p < 0.001). Curve and profile edges resulting from disconnection of rod-like trabeculae increased by 9.8% and 5.1% (p = 0.0001 and <0.001, respectively). Similarly, DXA BMD in the spine and hip decreased 2.6% and 1.3% (p < 0.0001 and <0.005, respectively), and pQCT cortical area decreased 3.6% (p = 0.0001). However, neither trabecular density nor BV/TV changed. Furthermore, none of the parameters measured in the estradiol group were significantly different after 12 mo. Substantial differences in the mean changes from baseline between the estradiol treatment and control groups, in particular after 24 mo, were observed, with relative group differences as large as 13% (S/C, p = 0.005), and the relative changes in the two groups had the opposite sign for most parameters. The observed temporal alterations in architecture are consistent with remodeling changes that involve gradual conversion of plate-like to rod-like trabecular bone along with disconnection of trabecular elements, even in the absence of a net loss of trabecular bone. The high-resolution 3D rendered images provide direct evidence of the above remodeling changes in individual subjects. The radius structural data indicated similar trends but offered no definitive conclusions. CONCLUSIONS: The short-term temporal changes in trabecular architecture after menopause, and the protective effects of estradiol ensuring maintenance of a more plate-like TB architecture, reported here, have not previously been observed in vivo. This work suggests that MRI-based in vivo micromorphometry of trabecular bone has promise as a tool for monitoring osteoporosis treatment.

Trabecular structure quantified with the MRI-based virtual bone biopsy in postmenopausal women contributes to vertebral deformity burden independent of areal vertebral BMD.

UNLABELLED: In postmenopausal women with a wide range of vertebral deformities, MRI-based structural measures of topology and scale at the distal radius are shown to account for as much as 30% of vertebral deformity, independent of integral vertebral BMD. INTRODUCTION: Trabecular bone architecture has been postulated to contribute to overall bone strength independent of vertebral BMD measured by DXA. However, there has thus far been only sparse in vivo evidence to support this hypothesis. MATERIALS AND METHODS: Postmenopausal women, 60-80 yr of age, were screened by DXA, and those with T-scores at either the hip or spine falling within the range of -2.5 +/- 1.0 were studied with the MRI-based virtual bone biopsy, along with heel broadband ultrasound absorption and pQCT of the tibia. The data from 98 subjects meeting the enrollment criteria were subjected to microMRI at the distal tibia and radius, and measures of topology and scale of the trabecular bone network were computed. A spinal deformity index (SDI) was obtained from morphometric measurements in midline sagittal MR images of the thoracic and lumbar spine to evaluate associations between structure and deformity burden. RESULTS: A number of structural indices obtained at the distal radius were correlated with the SDI. Among these were the topological surface density (a measure of trabecular plates) and trabecular bone volume fraction, which were inversely correlated with SDI (p < 0.0001). Combinations of two structural parameters accounted for up to 30% of the variation in SDI (p < 0.0001) independent of spinal BMD, which was not significantly correlated. pQCT trabecular BMD was also weakly associated, whereas broadband ultrasound absorption was not. No significant association between SDI and structural indices were found at the tibia. CONCLUSIONS: Structural measures at the distal radius obtained in vivo by microMRI explained a significant portion of the variation in total spinal deformity burden in postmenopausal women independent of areal BMD.

Mineral volume and morphology in carotid plaque specimens using high-resolution MRI and CT.

OBJECTIVE: High-resolution MRI methods have been used to evaluate carotid artery atherosclerotic plaque content. The purpose of this study was to assess the performance of high-resolution MRI in evaluation of the quantity and pattern of mineral deposition in carotid endarterectomy (CEA) specimens, with quantitative micro-CT as the gold standard. METHODS AND RESULTS: High-resolution MRI and CT were compared in 20 CEA specimens. Linear regression comparing mineral volumes generated from CT (VCT) and MRI (VMRI) data demonstrated good correlation using simple thresholding (VMRI=-0.01+0.98VCT; R2=0.90; threshold=4xnoise) and k-means clustering methods (VMRI=-0.005+1.38VCT; R2=0.93). Bone mineral density (BMD) and bone mineral content (BMC [mineral mass]) were calculated for CT data and BMC verified with ash weight. Patterns of mineralization like particles, granules, and sheets were more clearly depicted on CT. CONCLUSIONS: Mineral volumes generated from MRI or CT data were highly correlated. CT provided a more detailed depiction of mineralization patterns and provided BMD and BMC in addition to mineral volume. The extent of mineralization as well as the morphology may ultimately be useful in assessing plaque stability.

Magnetization transfer micro-MR imaging of live excised lamprey spinal cord: characterization and immunohistochemical correlation.

BACKGROUND AND PURPOSE: Membrane constituents may play a key role in the magnetization transfer (MT) effect. In lamprey spinal cord, axonal diameters range from <1 microm in the dorsal region to 20-40 microm in the ventral region. There is a corresponding range of axonal, and hence cell membrane, density. These characteristics permit determination of the effect of cell membrane density on MT. The purpose of this study was to characterize regional MT effects in lamprey spinal cord. METHODS: Excised spinal cords from eight sea lampreys were measured with a 9.4-T MR imaging system. MT saturation was applied for spin-echo sequences. The MT ratio (MTR) was calculated in each location (dorsal, lateral, and ventral columns). Spinal cords from five other lampreys were prepared with an antibody to lamprey glial keratin (LCM 29). The percentage of area staining with LCM29 was calculated for each location. RESULTS: Mean MTR (+/- SD) for the dorsal, lateral, and ventral columns were 62.4 +/- 4.2, 59.2 +/- 2.7, and 56.9 +/- 3.0, respectively; all differences were significant (P < .05). Mean LCM29-positive areas for the dorsal, lateral, and ventral columns were 85.1%, 69.7%, and 50.9%, respectively. MTR and percentage LCM29-positive area were significantly correlated (r(2) = 0.98). CONCLUSION: Regional differences in MT effect exist in the lamprey spinal cord. MTR is well correlated with percentage LCM29-positive area. These results support the hypothesis that membrane constituents are at least partly responsible for regional variations in MT effect.