Significant risk factors for occurrence of cancer after renal transplantation: a single center cohort study of 1265 cases.

Occurrence of cancer after renal transplantation remains a major problem, and the second cause of death. We performed a retrospective analysis of first cancer, first skin cancer, and first organ cancer (including posttransplant lymphoproliferative disease [PTLD]) among 1265 cases from 1979 to 2006. The occurrence of cancer was clearly a time-dependent event justifiying the use of Kaplan-Meier survival and Cox regression methods. The 10-year cumulative incidences of first cancer, first skin cancer, and first organ cancer were 24.6%, 14.5%, and 14.5%, respectively. Recipient age was a major, independent risk factor for the 3 endpoints with a 6% increased relative risk for each year increment (P < .0001). Female gender was also a major, independent risk factor, but only for skin cancer (P = .0002). We could not demonstrate any difference between the immunosuppressive drugs used for induction or maintenance therapy, especially between antithymocyte globulin (ATG) vs anti-CD25, cyclosporine vs tacrolimus, and azathioprine vs mycophenolate mofetil. Large cohorts are needed with strict stratifications for recipient age and gender to detect any difference, if any, among the drugs.

Encapsulation of Biosynthesized Nanosilver in Silica Composites for Sustainable Antimicrobial Functionality.

Silver nanoparticles (AgNPs) have become known as a broad-spectrum antimicrobial agent. The antimicrobial activity of AgNPs is dependent on the particle size and the dispersion status. In this study, a simple and effective approach is developed for sequestering the biosynthesized AgNPs in silica composites during the gel formation of MCM-41. Composites with different Ag concentrations of 0.034% (Ag1@MCM-41), 0.151% (Ag2@MCM-41), and 0.369% (Ag3@MCM-41) are synthesized and then heated at 400 °C to produce Ag1@MCM-41H, Ag2@MCM-41H, and Ag3@MCM-41H, respectively. The samples are characterized by flame atomic absorption spectrometry, Fourier-transform infrared spectroscopy, X-ray diffraction, N2 physisorption, scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis. The AgNPs are confirmed to be highly dispersed in the amorphous silica framework. The antimicrobial activity of the AgNP-silica samples is investigated against Staphylococcus aureus, Escherichia coli, and Candida albicans using the cup-plate and the plate-count techniques. The results show an excellent antimicrobial effect of these samples against the studied microorganisms. Importantly, the AgNP-silica samples are found to be stable up to 58 months under ambient conditions. These stable and powerful antimicrobial composites provide a more practical and effective strategy for combating biomedical pathogens and public health threats.

Green Synthesis of Silver Nano-particles by Macrococcus bovicus and Its Immobilization onto Montmorillonite Clay for Antimicrobial Functionality.

Macrococcus bovicus was locally isolated from soil and used in the green synthesis of nano-scaling silver (NSAg). It was immobilized on a sodic-montmorillonite clay (MMT1) and cetyltrimethylammonium bromide-modified montmorillonite (MMT2) which was also calcined at 300 °C (MMT3). The NSAg clays were characterized by X-ray fluorescence, Fourier transform infrared spectra, X-ray diffractometry, surface area measurement, UV-Vis spectrometry, scanning electron microscope, transmission electron microscope and thermogravimetric analysis. NSAg was confirmed to be included in the interparticular cavities of the clay sheets and its mechanical stability was evidenced. The antimicrobial activity of the NSAg-modified clays was investigated against Staphylococcus aureus, Escherichia coli and Candida albicans using the cup plate and the plate count techniques. The antimicrobial activity of the NSAg clays was confirmed and attributed to the caging of NSAg in MMT cavities. MMT3 was found to inhibit the microbial growth to as high as 65 % as observed from the plate count method. Graphical Abstract Scheme of the biosynthesis of nano-scaling Ag and its immobilization and antimicrobial application.