Do perioperative antibiotics reduce the risk of surgical-site infections following excision of ulcerated skin cancers? A Critically Appraised Topic.

AIM: To review the efficacy of perioperative antibiotics in reducing the risk of surgical-site infections (SSIs) following excision of ulcerated skin cancers. SETTING AND DESIGN: Study selection, data extraction and analysis were carried out independently by four authors. Only randomized controlled trials (RCTs) reported in the English language were included. INCLUDED STUDIES: RCTs in the English language in which patients received perioperative topical, intralesional or oral antibiotics for dermatological surgery, including Mohs micrographic surgery in general practice, dermatology or plastic surgery departments, were included. OUTCOME: The proportion of participants developing SSI following excision of skin lesions. RESULTS: Thirteen RCTs were identified from our literature search of PubMed and Embase, which evaluated SSI following use of topical (n = 5), oral (n = 3), intramuscular (n = 2), intravenous (n = 1) and intralesional antibiotics (n = 2) in dermatological surgery. Two RCTs specifically investigated SSIs in ulcerated skin cancer excisions; one RCT investigated the SSI rate following surgical treatment specifically for ulcerated skin cancers in individuals randomized to topical antibiotics vs. oral cephalexin; and one RCT compared intravenous cefazolin with no antibiotic, demonstrating significant reduction in SSI rates for ulcerated tumours (P = 0·04). CONCLUSIONS: The heterogeneity of the RCTs included in this study makes it difficult to make a direct comparison of the outcomes measured. High-quality evidence demonstrating a beneficial effect of the use of perioperative antibiotics to prevent SSI following excision of ulcerated skin cancers is lacking. In the absence of an evidence base, we propose that a well-designed multicentre RCT could evaluate the effect of perioperative antibiotics following excision of ulcerated tumours, and potentially reduce inappropriate antibiotic prescription.

Role of monensin PLGA polymer nanoparticles and liposomes as potentiator of ricin A immunotoxins in vitro.

Monensin is a carboxylic ionophore which can potentiate the activity of ricin based immunotoxins (IT) in vitro and in vivo against a variety of human tumours. Monensin was encapsulated into nanoparticles (NP) by using biodegradable poly(DL-lactide-co-glycolide) (PLGA, 50:50). The NP were prepared by modified emulsification-solvent evaporation method. High shear homogenization followed by simultaneous stirring and bath sonication were used for preparing NP. The size of NP was determined by photon correlation spectroscopy using a BI 90 particle sizer (Brookhaven Instruments). The average size of NP could be decreased from 567 nm to 163 nm by increasing the concentration of polyvinyl alcohol from 10% to 100% of PLGA. The NP were spherical in shape as observed by Atomic Force Microscopy. The concentration of monensin in the NP was analyzed by HPLC and the entrapment efficiency was found to be more than 12%. The zeta potential of NP was -25.8 (+/- 1.3) mv, which did not change significantly after resuspension of the freeze dried sample. The NP were tested against HL-60 and HT-29 human tumour cell lines in vitro. Monensin NP potentiated the activity of IT by 40 to 50 times against these cell lines. There was however, no difference between the NP and liposomes for their potentiating affect of IT against the two tumour cell lines.