silicon and Carcinoma--Squamous-Cell

Tracheal replacement after extensive resection remains a challenge for the thoracic surgeon. We propose an innovative solution: the use of an aortic autograft. After an experimental work on animals with aortic autografts and allografts [Martinod E, Seguin A, Pfeuty K, Fornes P, Kambouchner M, Azorin JF, Carpentier AF. Long-term evaluation of the replacement of the trachea with an autologous aortic graft. Ann Thorac Surg 2003;75(5):1572-8; Martinod E, Seguin A, Holder-Espinasse M, Kambouchner M, Duterque-Coquillaud M, Azorin JF, Carpentier AF. Tracheal regeneration following tracheal replacement with an allogenic aorta. Ann Thorac Surg 2005;79(3):942-8], we present the first human case of long tracheal replacement with an aortic autograft. In this case we replaced 7 cm of a tumoral trachea using an aortic infra-renal autograft supported by a silicone stent. The early postoperative course was uneventful. The stent was removed at three months. The patient died at six months from an acute pulmonary infection without any sign of anastomosis leakage or graft rupture. A new field of clinical study has to be investigated.

Topics: Aged; Aorta; Blood Vessel Prosthesis Implantation; Carcinoma, Squamous Cell; Fatal Outcome; Humans; Male; Silicon; Stents; Trachea; Tracheal Neoplasms; Transplantation, Autologous; Treatment Outcome

This paper reports on pulmonary dust retention in a man who worked 42 years in the vicinity of an Acheson furnace of a silicon carbide plant and had a carborundum pneumoconiosis. Special attention is paid to the retained silicon carbide fibers in the lung parenchyma. The concentration of silicon carbide fibers longer than 5 microns is 39,300 fibers/mg dry lung. These fibers have a similar morphology to fibers observed in the working environment. The result is compared to pulmonary retention of workers exposed to asbestos.

Topics: Carbon; Carbon Compounds, Inorganic; Carcinoma, Squamous Cell; Humans; Lung Neoplasms; Male; Microscopy, Electron, Scanning Transmission; Occupations; Pneumoconiosis; Pneumonectomy; Silicon; Silicon Compounds

Malignant central airway obstruction around the main carina often requires placement of Y‑shaped stents. In this study, we aimed to determine the safety of silicone Y stents placed around the main carina in the malignant airway obstruction by examining the long term complications, emergence times and treatment approaches of complications.. Between May 2012 and July 2015, 47 silicone Y stents were placed in 46 patients with malignant external compression or mixed type stenosis around the main carina. Patient stents were placed via rigid bronchoscopy under total intravenous anesthesia in operating room conditions.. In the half of the patients (23/46), stents were placed under urgent conditions due to acute respiratory failure. Stents were deployed successfully in all the patients. No procedure related deaths were observed. The median time of survival following stent insertion was 157 days. The total long-term complication rate of silicone Y stents was 28.3%. Mucostasis (8.7%) and migration (2.2%) were observed within the first month after placement of the silicone Y stents (median 18 days), stent-edge granulation tissue development (13.0%) was observed at the earliest one month (median 64, range 34-386 days) and stent-edge tumor tissue development (4.3%) were observed at the earliest 3 months (median 151, range 85-217 days). A total of 7 (15.2%) stents were removed, 2 of which were due to mucostasis and 5 of which were due to granulation tissue development. One patient's stent was replaced with a longer silicone Y stent due to stent-edge tumor tissue development.. The best palliative treatment of malignant tumor stenosis around the main carina is still silicone Y stent placement, but the long-term complication rate can be high. For this group of patients, bronchoscopy to be performed at the first and third months after silicone Y stent placement may provide early detection of stent-edge tissue development.

Topics: Adult; Aged; Aged, 80 and over; Airway Obstruction; Bronchography; Bronchoscopy; Carcinoma, Squamous Cell; Constriction, Pathologic; Female; Humans; Lung Neoplasms; Male; Middle Aged; Prosthesis Failure; Retrospective Studies; Silicon; Silicones; Stents; Trachea; Treatment Outcome

A hierarchical three-dimensional network of carbon nanotubes on Si pillar substrate (3DN-CNTs) was developed for the accurate detection of oral squamous cell carcinoma (OSCC) in clinical saliva samples. The 3DN-CNTs were uniformly coated with a layer of aluminum oxides to enhance structural stability during biomarker detection. Cytokeratin-19 antigen (Cyfra 21-1) was utilized as a model biomarker of OSCC for fluorescence-based immunosensor using 3DN-CNTs (3DN-CNTs sensor). The 3DN-CNTs sensor enhances the sensitivity of Cyfra 21-1 detection by increasing the density of immobilized antibody through high surface area of 3DN-CNTs and enhancing the accessibility of biomolecules through the ordered pathway of hierarchical structure. The reliable detection limit for sensing of Cyfra 21-1 was estimated as in the level of 0.5 ng/mL and the quantitative estimation of Cyfra 21-1 was analyzed by 4-parameter logistic (4-PL) model for curve-fitting analysis. Clinical applicability of 3DN-CNTs sensor was evaluated through correlation with the commercially available electrochemiluminescence (ECL) detection system in the hospital. The assay results of the two systems for clinical saliva samples showed a good linear correlation. The 3DN-CNTs sensor offers great potential for accurate diagnosis of OSCC using Cyfra 21-1 biomarker in clinical fluids.

Topics: Aluminum Oxide; Antibodies, Immobilized; Antigens, Neoplasm; Biomarkers, Tumor; Biosensing Techniques; Carcinoma, Squamous Cell; Electrochemical Techniques; Fluorescence; Humans; Keratin-19; Limit of Detection; Luminescent Measurements; Mouth Neoplasms; Nanotubes, Carbon; Saliva; Silicon

Silicon nanowire (SiNW) field-effect transistor (FET) biosensors have already been used as powerful sensors for the direct detection of disease-related biomarkers. However, the multiplexed detection of biomarkers in real samples is still challenging. Interleukin 8 (IL-8) and tumor necrosis factor α (TNF-α) are two typical biomarkers of oral squamous cell carcinoma (OSCC). In this study, we developed a multiplexed detection methodology for IL-8 and TNF-α detection in saliva using SiNW FET biosensors. We fabricated the SiNW FET sensors using a top-down lithography fabrication technique. Subsequently, we achieved the multiplexed detection of two biomarkers in saliva by specific recognition of the two biomarkers with their corresponding antibodies, which were modified on the SiNW. The established method was found to have a limit of detection as low as 10 fg/mL in 1 × PBS as well as 100 fg/mL in artificial saliva. Because of its advantages, including label-free and multiplexed detection, non-invasive analysis, highly sensitive and specific determination, the proposed method is expected to be widely used for the early diagnosis of OSCC.

Topics: Animals; Biomarkers, Tumor; Biosensing Techniques; Buffers; Carcinoma, Squamous Cell; Early Detection of Cancer; Humans; Interleukin-8; Mouth Neoplasms; Nanowires; Saliva; Silicon; Transistors, Electronic; Tumor Necrosis Factor-alpha

We generated low-flux X-ray micro-planar beams (MPBs) using a laboratory-scale industrial X-ray generator (60 kV/20 mA) with custom-made collimators with three different peak/pitch widths (50/200 μm, 100/400 μm, 50/400 μm). To evaluate normal skin reactions, the thighs of C3H/HeN mice were exposed to 100 and 200 Gy MPBs in comparison with broad beams (20, 30, 40, 50, 60 Gy). Antitumor effects of MPBs were evaluated in C3H/HeN mice with subcutaneous tumors (SCCVII). After the tumors were irradiated with 100 and 200 Gy MPBs and 20 and 30 Gy broad beams, the tumor sizes were measured and survival analyses were performed. In addition, the tumors were excised and immunohistochemically examined to detect γ-H2AX, ki67 and CD34. It was shown that antitumor effects of 200 Gy MPBs at 50/200 μm and 100/400 μm were significantly greater than those of 20 Gy broad beams, and were comparable with 30 Gy broad beams. γ-H2AX-positive cells demonstrated clear stripe-patterns after MPB irradiation; the pattern gradually faded and intermixed over 24 h. The chronological changes in ki67 positivity did not differ between MPBs and broad beams, whereas the CD34-positive area decreased significantly more in MPBs than in broad beams. In addition, it was shown that skin injury after MPB irradiation was significantly milder when compared with broad-beam irradiation at equivalent doses for achieving the same tumor control effect. Bystander effect and tumor vessel injury may be the mechanism contributing to the efficacy of MPBs.

Topics: Animals; Antigens, CD34; Bystander Effect; Carcinoma, Squamous Cell; Dermatitis; Dose-Response Relationship, Radiation; Equipment Design; Immunohistochemistry; Ki-67 Antigen; Mice; Mice, Inbred C3H; Neoplasm Transplantation; Neoplasms; Radiation Injuries; Radiometry; Silicon; Skin; Time Factors; X-Rays

Microbubbles are spherical cavities formed in thermally cured polydimethylsiloxane (PDMS) using the gas expansion molding technique. Microbubble cavity arrays are generated by casting PDMS over a silicon wafer mold containing arrays of deep etched pits. To be useful in various high throughput cell culture and sorting applications it is imperative that uniform micron-sized cavities can be formed over large areas (in(2)). This paper provides an in-depth quantitative analysis of the fabrication parameters that effect the microbubble cavity formation efficiency and size. These include (1) the hydrophobic coating of the mold, (2) the mold pit dimensions, (3) the spatial arrangement of the pit openings, (4) the curing temperature of PDMS pre-polymer, (5) PDMS thickness, and (6) the presence and composition of residual gas in the PDMS pre-polymer mixture. Results suggest that the principles of heterogeneous nucleation and gas diffusion govern microbubble cavity formation, and that surface tension prevents detachment of the vapor bubble that forms in the PDMS over the pit. Paramerters are defined that enable the fabrication of large format arrays with uniform cavity size over 6 in(2) with a coefficient-of-variation <10 %. The architecture of the microbubble cavity is uniquely advantageous for cell culture. Large format arrays provide a highly versatile system that can be adapted for use in various high-throughput cell sorting applications. Herein, we demonstrate the use of microbubble cavity arrays to dissect the cellular heterogeneity that exists in a tumorigenic cutaneous squamous cell carcinoma cell line at the single cell level.

Topics: Carcinoma, Squamous Cell; Cell Culture Techniques; Cell Line, Tumor; Cell Separation; Dimethylpolysiloxanes; Evaluation Studies as Topic; Hot Temperature; Humans; Microbubbles; Neoplastic Stem Cells; Polymers; Silicon; Single-Cell Analysis; Surface Properties

Asbestos exhibits many properties of classical tumor promoters. These characteristics include the ability to stimulate proliferation and inhibit normal differentiation of cells. In organ cultures of trachea, crocidolite and amosite asbestos stimulate squamous metaplasia, a pathological process in which a rapidly proliferating squamous epithelium replaces the normal epithelium. We hypothesized that the induction of metaplasia depends upon the fibrous nature of asbestos. Accordingly, several naturally occurring and synthetic fibrous materials and their nonfibrous analogues were assessed for their ability to induce metaplastic changes in tracheal mucosa of the Syrian hamster. Exposure to both crocidolite asbestos and fiberglass resulted in significant increases (p less than 0.05) in squamous metaplasia over a range of dosages (1.0, 4.0, 16.0 mg/ml). Attapulgite (palygorskite) and both "long-" and "short-" fiber preparations of chrysotile asbestos had similar but less marked effects. Nonfibrous analogues of each material (riebeckite, antigorite, and glass particles) failed to produce metaplasia. Asbestos, and fibrous materials in general, appear to stimulate squamous metaplasia because of their fibrous geometry.

Topics: Animals; Asbestos; Carcinoma, Squamous Cell; Cricetinae; Glass; Magnesium; Magnesium Compounds; Microscopy, Electron, Scanning; Organ Culture Techniques; Silicon; Silicon Compounds; Structure-Activity Relationship; Tracheal Neoplasms

Total ablation of the pinna gives an unsatisfactory cosmetic result which has to be corrected. Plastic surgery procedures are generally not very successful and some sort of episthesis is preferred by many. The attachment of an episthesis is, however, often a problem. This paper is a case report of a new type of episthesis fixation arrangement. In a first session four titanium screws were implanted into the temporal bone above and behind the external meatus with a technique ensuring minimal tissue violation. Three months later when these screws were firmly integrated in the living bone, skin-penetrating titanium abutments were connected and a gold bridge was adapted to the abutments. A silicon rubber episthesis was attached to the bridge with a snap fastener. Behind this new method of episthesis attachment are several years of clinical experience of titanium implants directly anchored into various living bones and allowed to permanently penetrate skin or mucous membrane.

Topics: Carcinoma, Squamous Cell; Ear Neoplasms; Ear, External; Gold; Humans; Male; Middle Aged; Parotid Neoplasms; Prostheses and Implants; Prosthesis Design; Silicon; Temporal Bone; Titanium

The Growing importance of industrial noxae for carcinogenesis will, in the course of further progressive mechanization and industrialization, suggest an increasing confrontation with this problem. The above mentioned case, a patient working with insulating materials on industrial heating systems, impressevely demonstrates the transformation of chronic laryngitis into a carcinoma in the course of years, brought about by industrial influences and thus proving the exogenous origin of this genesis. Dust as well as strong effects of heat under conditions of variable atmospheric humidily are concerned to be principal damaging factors.

Topics: Asbestos; Carcinoma, Squamous Cell; Chronic Disease; Construction Materials; Dust; Heating; Humans; Humidity; Laryngeal Neoplasms; Laryngitis; Male; Middle Aged; Occupational Diseases; Occupations; Silicon