Antifungal efficiency of chemically and thermally-activated acrylic resins after surface treatment using poly (diallyldimethylammonium chloride)

Abstract INTRODUCTION: Acrylic resins are used in the preparation of facial prostheses and may be colonized by fungi. Here, we verified the antifungal efficacy of this material after surface treatment using poly (diallyldimethylammonium chloride). METHODS: Acrylic resin specimens with and without surface treatment were subjected to tests for fungistatic and fungicidal activities. Standard strains of Candida albicans and Aspergillus niger were used. RESULTS: After surface treatment, the fungistatic and fungicidal efficacies of the resins against C. albicans and fungistatic action against A. niger were verified. CONCLUSIONS: The surface treatment was a determinant of the antifungal activity of the material.

In vitro studies of multiwalled carbon nanotube/ultrahigh molecular weight polyethylene nanocomposites with osteoblast-like MG63 cells

Carbon nanotubes are highly versatile materials; new applications using them are continuously being developed. Special attention is being dedicated to the possible use of multiwalled carbon nanotubes in biomaterials contacting with bone. However, carbon nanotubes are also controversial in regards to effects exerted on living organisms. Carbon nanotubes can be used to improve the tribological properties of polymer/composite materials. Ultrahigh molecular weight polyethylene (UHMWPE) is a polymer widely used in orthopedic applications that imply wear and particle generation. We describe here the response of human osteoblast-like MG63 cells after 6 days of culture in contact with artificially generated particles from both UHMWPE polymer and multiwalled carbon nanotubes (MWCNT)/UHMWPE nanocomposites. This novel composite has superior wear behavior, having thus the potential to reduce the number of revision hip arthroplasty surgeries required by wear failure of acetabular cups and diminish particle-induced osteolysis. The results of an in vitro study of viability and proliferation and interleukin-6 (IL-6) production suggest good cytocompatibility, similar to that of conventional UHMWPE (WST-1 assay results are reported as percentage of control ± SD: UHMWPE = 96.19 ± 7.92, MWCNT/UHMWPE = 97.92 ± 8.29 percent; total protein: control = 139.73 ± 10.78, UHMWPE = 137.07 ± 6.17, MWCNT/UHMWPE = 163.29 ± 11.81 µg/mL; IL-6: control = 90.93 ± 10.30, UHMWPE = 92.52 ± 11.02, MWCNT/UHMWPE = 108.99 ± 9.90 pg/mL). Standard cell culture conditions were considered as control. These results, especially the absence of significant elevation in the osteolysis inductor IL-6 values, reinforce the potential of this superior wear-resistant composite for future orthopedic applications, when compared to traditional UHMWPE.

Efficacy and safety of sevelamer. Comparison with calcium carbonate in thereatment of hyperphosphatemia in hemodialysis patients

Current phosphate binders used in hemodialysis patients include calcium-based binders that result in frequent hypercalcemia. The use of a calcium- and aluminum-free phosphate-binding polymer in hemodialysis [sevelamer] disclosed efficacy in the short and long-term studies. However, due to race differences we performed a short-term study on the Saudi hemodialysis patients and compared sevelamer with a standard calcium-based phosphate binder. An open-label, randomized, cross-over study was performed to evaluate the safety and effectiveness of sevelamer hydrochloride in controlling hyperphosphatemia in hemodialysis patients. After a 2-week phosphate binder washout period, stable hemodialysis patients were given either sevelamer or calcium carbonate, and the dosages were titrated to achieve phosphate control over an 8-week period. After a 2-week washout period, patients crossed over to the alternate agent for 8 weeks. Twenty patients from the Dialysis Unit of King Fahd Hospital, Jeddah, Kingdom of Saudi Arabia, were recruited for the study between March 2003 and June 2003. There was a similar decrease in serum phosphate values over the course of the study with both sevelamer [-3.3 +/- 2.2 mg/dL] and calcium carbonate [-3.9 +/- 2.8 mg/dL]. Fifty-two% of patients developed serum calcium greater than 2.75 mmol/L [11.0 mg/dL] while receiving calcium carbonate versus 26% of patients receiving sevelamer [p<0.05]. The incidence of hypercalcemia for sevelamer was not different from the incidence of hypercalcemia during the washout period. Patients treated with sevelamer also sustained a 13% mean decrease in serum cholesterol levels. Sevelamer was effective in controlling hyperphosphatemia without resulting in an increase in the incidence of hypercalcemia seen with calcium carbonate. This agent appears quite effective in the treatment of hyperphosphatemia in hemodialysis patients, and its usage may be advantageous in the treatment of dialysis patients

Update on the use of polyethylene intramammary device [IMD] in mastitis control

IMD are small flexible organic polymer loop inserted aseptically into the gl and cistern of the udder to stimulate an immune response and increase levels of milk somatic cell counts [MSCC] within the mammary gl and to a number sufficient to create a leucocytic barrier against intramammary infection [IMI], this was shown after experimental challenge with Staphylococcus aureus, Escherichia coli, Streptococcus uberis, Streptococcus agalactiae,. etc. into quarters fitted with IMD compared to control quarters. Results from field testing of the abraded IMD indicated that it was highly successful in reducing the incidence of clinical mastitis. The effect of IMD on milk yield is conflicting but generally is not significant. Immunization appeared to confer additional protection to mammary quarters containing IMD. The lack of any difference in N-acetyl-beta-D-glucosaminidase [NAGase] activity and RBCs concentration in milk between IMD and control quarters, indicated no damage to milk secretory tissues due to IMD. The IMD appeared to be well tolerated by dairy cows and abnormal side effects were not a problem, and in general it offers promise in the control mastitis