silicon and Cicatrix

The injection of fluid silicone was formerly an acceptable therapy for recontouring post-traumatic or age-related changes of the face and neck. About 20 years after the use of silicone injections, the number of patients presenting with late complications is increasing. Such complications include migration of the silicone, granuloma formation, chronic cellulitis, skin ulcers and and scarring, all of which are difficult to treat medically or surgically. Recent data in the literature support the notion that fluid silicon is a potential carcinogen. These patients require a careful approach combining the limited surgical possibilities with the support needed to live with such a problem. Using a case report as an example, we discuss the diagnostic and therapeutic problems associated with this phenomenon which is relatively uncommon in Europe.

Topics: Cellulitis; Cicatrix; Female; Foreign-Body Migration; Humans; Injections; Middle Aged; Plastic Surgery Procedures; Risk Assessment; Silicon; Skin Ulcer

To study microstructure, friction and wear behaviors of silicon-lithium spray coating on the surface of zirconia ceramics and to preliminarily evaluate its esthetic so as to provide support and guidance for the clinical application.. The microstructures of the silica-lithium spray coatings on the untreated and preliminarily polished zirconia ceramic surfaces showed the protruding defects, and the line roughness of coating group was larger than that of the polishing group. The median thickness of the silica-lithium spray coating on the preliminarily polished zirconia ceramic was 13.0 μm (interquartile range, IQR: 11.6, 17.9), while that of the silica-lithium spray coating on the untreated zirconia ceramic was 4.4 μm (IQR: 4.1, 4.7). The Vickers hardness and wear rate of the coating group were between the polishing group and the glazing group. The wear depths of the wear scars of steatite ceramics were the glazing group, coating group, and polishing group in descending order, and there was statistically significant difference between glazing and polishing groups (. The silica-lithium spray coating on the zirconia ceramic, can be used as a new method for zirconia ceramic surface treatment, because it can increase the esthetic of zirconia ceramics compared with polishing and reduce the wear of steatite ceramics compared with glazing.

Topics: Ceramics; Cicatrix; Dental Porcelain; Friction; Humans; Lithium; Materials Testing; Silicon; Silicon Dioxide; Surface Properties; Zirconium

Topics: Cicatrix; Esthetics; Facial Injuries; Female; Humans; Male; Margins of Excision; Reoperation; Silicon; Suture Techniques; Treatment Outcome

Neural electrodes could significantly enhance the quality of life for patients with sensory and/or motor deficits as well as improve our understanding of brain functions. However, long-term electrical connectivity between neural tissue and recording sites is compromised by the development of astroglial scar around the recording probes. In this study we investigate the effect of a nanoscale laminin (LN) coating on Si-based neural probes on chronic cortical tissue reaction in a rat model. Tissue reaction was evaluated after 1 day, 1 week, and 4 weeks post-implant for coated and uncoated probes using immunohistochemical techniques to evaluate activated microglia/macrophages (ED-1), astrocytes (GFAP) and neurons (NeuN). The coating did not have an observable effect on neuronal density or proximity to the electrode surface. However, the response of microglia/macrophages and astrocytes was altered by the coating. One day post-implant, we observed an approximately 60% increase in ED-1 expression near LN-coated probe sites compared with control uncoated probe sites. Four weeks post-implant, we observed an approximately 20% reduction in ED-1 expression along with an approximately 50% reduction in GFAP expression at coated relative to uncoated probe sites. These results suggest that LN has a stimulatory effect on early microglia activation, accelerating the phagocytic function of these cells. This hypothesis is further supported by the increased mRNA expression of several pro-inflammatory cytokines (TNF-alpha, IL-1 and IL-6) in cultured microglia on LN-bound Si substrates. LN immunostaining of coated probes immediately after insertion and retrieval demonstrates that the coating integrity is not compromised by the shear force during insertion. We speculate, based on these encouraging results, that LN coating of Si neural probes could potentially improve chronic neural recordings through dispersion of the astroglial scar.

Topics: Animals; Cells, Cultured; Cerebral Cortex; Cicatrix; DNA Primers; Electrodes, Implanted; Glial Fibrillary Acidic Protein; Gliosis; Immunohistochemistry; Interleukin-1; Interleukin-6; Laminin; Male; Microelectrodes; Microscopy, Electron, Scanning; Nanotechnology; Neuroglia; Neurons; Polyethyleneimine; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; Silicon; Tumor Necrosis Factor-alpha

A case of a 28-year-old woman with infiltration of sarcoidosis scar tissue after blepharoplasty is reported. Nodules developed two times in her right upper eyelid about 1 and 2 years after blepharoplasty of both eyes and they were resected each time, but eruption recurred. Ophthalmic examination revealed aqueous flare and cells, snowball vitreous opacities, and retinal periphlebitis. A chest X-ray disclosed bilateral hilar lymphadenopathy (BHL). Laboratory studies showed an elevation of the serum angiotensin converting enzyme (ACE). Light microscopy revealed epithelioid granuloma with no caseation necrosis in a biopsy specimen, Viewing through polarized light demonstrated crystalline-like foreign bodies with bi-refringence in the epithelioid granuloma. Electron microscopic X-ray microanalysis confirmed these foreign bodies to be composed of Si, Mg, and O. These findings indicate that this skin lesion was caused by an infiltration of sarcoidosis scar tissue.

Topics: Adult; Blepharoplasty; Cicatrix; Electron Probe Microanalysis; Eyelid Diseases; Female; Humans; Magnesium; Oxygen; Sarcoidosis; Silicon; Skin Diseases

The surgeon will be better able to cope with the problem of scars as he understands the nature of wound healing and as advances are made in the knowledge of the physiology and biochemistry of tissues. Still there do remain the all-important careful handling of tissues, adequate wound repair, and adequate postoperative care of the wound and the patient.

Topics: Accidents, Traffic; Automobile Driving; Burns; Cicatrix; Dermabrasion; Facial Injuries; Hair; Humans; Keloid; Methods; Postoperative Care; Preoperative Care; Silicon; Skin Transplantation; Surgery, Plastic; Suture Techniques; Tattooing; Transplantation, Autologous; Wound Healing; Wound Infection

Topics: Breast; Cicatrix; Female; Humans; Injections; Prostheses and Implants; Silicon; Surgery, Plastic