SiO2-CaO-P2O5 (58S) sol gel glass applied onto surgical grade stainless steel by spray technique: morphological characterization by digital image processing

AISI 316L stainless steel is commonly used as a low-cost material for permanent implants. It can be protected for degradation and corrosion by applying a hybrid silica based coating. Also the bioactive response of the implant can only be achieved by functionalizing the coated implant surface. The aim of this work is to synthesize and characterize a sol-gel made glass particles from the system SiO2-CaO-P2O5 with potential as bone inductive material, with and without an aging treatment of the precursor solution. The glass was synthesized by sol-gel technique that, comparing with melt glasses, generates an open net structure that could lead to particle dissolution and apatite deposition for biological purposes. The synthesized glass is dispersed by spray onto AISI 316L protected by a hybrid silica based coating, generating deposits with different size and morphology. To characterize the particles composition, microRaman spectroscopy was applied. It showed that no significant changes were reached after aging or thermal treatment of the deposited particles. Image processing techniques based on Mathematical Morphology were used to analyze morphology and sizes of the deposits obtain with the different sols (aged and no aged). Aproximately 50% of the surface was covered with particles made with a glass aged, and a 25% of covered area was reached with no aged one. When no aged glass particles were deposited, the particle size distribution shows the presence of many big particles with a roundness factor between 0.8 and 1 in a high percentage, meaning that they are spherical due to the presence of solvent and with a more open glass structure in the no aged glass. The Digital Image Processing and Raman spectroscopy tools help to analyze, characterize and quantify the bioactive particles deposited onto coated surgical grade stainless steel in terms of morphology, distribution and composition.

SDF-1 in myocardial repair

Stem cell therapy for the prevention and treatment of cardiac dysfunction holds significant promise for patients with ischemic heart disease. Excitingly early clinical studies have demonstrated safety and some clinical feasibility, while at the same time studies in the laboratory have investigated mechanisms of action and strategies to optimize the effects of regenerative cardiac therapies. One of the key pathways that has been demonstrated critical in stem cell-based cardiac repair is (stromal cell-derived factor-1) SDF-1:CXCR4. SDF-1:CXCR4 has been shown to affect stem cell homing, cardiac myocyte survival and ventricular remodeling in animal studies of acute myocardial infarction and chronic heart failure. Recently released clinical data suggest that SDF-1 alone is sufficient to induce cardiac repair. Most importantly, studies like those on the SDF-1:CXCR4 axis have suggested mechanisms critical for cardiac regenerative therapies that if clinical investigators continue to ignore will result in poorly designed studies that will continue to yield negative results.

p53 protein expression in benign lesions of the upper respiratory tract

OBJECTIVE

p53 is a tumor suppressor gene that is lost or mutated in most forms of human malignancy. There are, however, very few studies evaluating p53 expression in normal epithelium or benign lesions.

DESIGN

We screened for p53 protein expression in a variety of benign epithelial lesions of upper respiratory tract using monoclonal antibody DO-1 on paraffin-embedded material.

SUBJECTS

We studied a total of 109 cases: 16 cases of juvenile and 36 cases of adult laryngeal papillomatosis, 10 cases each of laryngeal nodules and laryngeal polyps, 17 cases of inverted papilloma, and 20 cases of nasal polyps.

RESULTS

Nuclear immunoreactivity for p53 protein was demonstrated in 14 (88%) of 16 cases of juvenile laryngeal papillomatosis, 33 (92%) of 36 cases of adult laryngeal papillomatosis, 4 (40%) of 10 cases of laryngeal nodules, 8 (80%) of 10 cases of laryngeal polyps, 7 (41%) of 17 cases of inverted papilloma, and 2 (10%) of 20 cases of nasal polyps. These results pertained only to the basal epithelial layer in all cases of laryngeal nodules, laryngeal polyps, and nasal polyps. Intermediate layer cells were also positive for p53 in the majority of the cases of both juvenile (69%) and adult (75%) laryngeal papillomatosis and in a minority of the cases of inverted papilloma (18%).

CONCLUSIONS

Overexpression of p53 protein is commonly demonstrable in benign epithelial lesions of the upper respiratory tract. This observation suggests that p53 protein accumulation may occur in the absence of mutation of the p53 gene and may correlate with epithelial proliferative activity.

True synovial metaplasia of breast implant capsules: a light and electron microscopic study

The formation of true synovial-lined membranes at tissue sites not intimately related to an articulation or a tendon sheath has been described in a variety of pathologic and postsurgical conditions, but until recently has not been well recognized to occur in association with tissue surrounding silicone breast implants. Of 15 cases with resected periprosthetic breast capsules, 7 (47%) demonstrated true synovial metaplasia with capsule-implant interfaces lined by typical synovial cells. Histochemical and immunohistochemical staining reactions were essentially identical to those observed in synovial control cases and featured positive reactions to Alcian blue-periodic acid-Schiff, reticulin, and vimentin. Focal positive immunoreactivity was observed with alpha 1-antitrypsin, alpha 1-antichromotrypsin, lysozyme, and CD68. No immunoreactivity was observed with cytokeratin AE1/AE3, S-100 protein, carcinoembryonic antigen, or basement membrane antigens. Transmission electron microscopy of the lining cells confirmed their true synovial nature with the type A (macrophage-like) cells, type B (fibroblast-like) cells, and intermediate forms or type AB cells identified. We conclude that the cellular lining surrounding silicone breast implants is a true synovial membrane, that synovial metaplasia may occur in nearly one half of all resected periprosthetic capsules, and that awareness of this entity will enable the surgical pathologist to render an accurate histopathologic diagnosis.

Sertoli-Leydig cell tumor of the ovary producing alpha-fetoprotein

A 16-year-old girl with virilization and elevated serum alpha-fetoprotein (AFP) levels was found to have a Sertoli-Leydig cell tumor of the ovary. Immunoperoxidase studies using anti-AFP localized AFP in cells with the histologic appearance of Leydig cells. Serum AFP fell to undetectable levels after excision of the tumor. The patient is alive and well 1 year postexcision.