Pre-intravitrael injection preparation: endophthalmitis prevention and the importance of povidone-iodine

Despite adherence to strict standards of care in preparation for intravitreal injections, endophthalmitis can still occur. This article focuses on endophthalmitis and the importance of povidone-iodine in pre-procedure antisepsis. An overview of endophthalmitis and an examination of the benefits of povidone-iodine in ocular aseptic technique for the prevention of post-procedure endophthalmitis are provided. The misconceptions that patients and health practitioners may have in relation to povidone-iodine hypersensitivity are also explored.

Immediate breast reconstruction after mastectomy for cancer

Background: Immediate breast reconstruction after mastectomy has increased over the past decade following the unequivocal demonstration of its oncological safety and the availability of reliable methods of reconstruction. Broadly, it is undertaken in the treatment of breast cancer, after prophylactic mastectomy in high-risk patients, and in the management of treatment failure after breast-conserving surgery and radiotherapy. Immediate breast reconstruction can be achieved reliably with a variety of autogenous tissue techniques or prosthetic devices. Careful discussion and evaluation remain vital in choosing the correct technique for the individual patient.

Methods: This review is based primarily on an English language Medline search with secondary references obtained from key articles.

Results and conclusion: Immediate breast reconstruction is a safe and acceptable procedure after mastectomy for cancer; there is no evidence that it has untoward oncological consequences. In the appropriate patient it can be achieved effectively with either prosthetic or autogenous tissue reconstruction. Patient selection is important in order to optimize results, minimize complications and improve quality of life, while simultaneously treating the malignancy. Close cooperation and collaboration between the oncological breast and reconstructive achieve these objectives.

Increase in microbial contamination risk with compression of the lid margin in eyes having cataract surgery

Purpose: To assess the bacterial contamination risk in cataract surgery associated with mechanical compression of the lid margin immediately after sterilization of the ocular surface.

Setting: Department of Cataract, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.

Design: Prospective randomized controlled double-masked trial.

Methods: Patients with age-related cataract were randomly assigned to 1 of 2 groups. In Group A (153 eyes), the lid margin was compressed and scrubbed for 360 degrees 5 times with a dry sterile cotton-tipped applicator immediately after ocular sterilization and before povidone-iodine irrigation of the conjunctival sac. Group B (153 eyes) had identical sterilization but no lid scrubbing. Samples from the lid margin, liquid in the collecting bag, and aqueous humor were collected for bacterial culture. Primary outcome measures included the rate of positive bacterial culture for the above samples. The species of bacteria isolated were recorded.

Results: Group A and Group B each comprised 153 eyes. The positive rate of lid margin cultures was 54.24%. The positive rate of cultures for liquid in the collecting bag was significantly higher in Group A (23.53%) than in Group B (9.80%) (P=.001).The bacterial species cultured from the collecting bag in Group B were the same as those from the lid margin in Group A. The positive culture rate of aqueous humor in both groups was 0%.

Conclusion: Mechanical compression of the lid margin immediately before and during cataract surgery increased the risk for bacterial contamination of the surgical field, perhaps due to secretions from the lid margin glands.

Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

THE EFFECTS OF 3 NON-ANTIBIOTIC, ANTIMICROBIAL AGENTS ON THE SURFACE HYDROPHOBICITY OF CERTAIN MICROORGANISMS EVALUATED BY DIFFERENT METHODS

The effects of three non-antibiotic, antimicrobial agents (taurolidine, chlorhexidine acetate and providone-iodine) on the surface hydrophobicity of the clinical strains Escherichia coli, Staphylococcus saprophyticus, Staphylococcus epidermidis and Candida albicans were examined. Three recognized techniques for hydrophobicity measurements, Bacterial Adherence to Hydrocarbons (BATH), the Salt Aggregation Test (SAT) and Hydrophobic Interaction Chromatography (HIC) were compared. At concentrations reported to interfere with microbial-epithelial cell adherence, all three agents altered the cell surface hydrophobicity. However, these effects failed to exhibit a uniform relationship. Generally, taurolidine and povidone-iodine treatments decreased the hydrophobicity of the strains examined whereas chlorhexidine acetate effects depended upon the micro-organism treated. Subsequently, the exact contribution of altered cell surface hydrophobicity to the reported microbial anti-adherence effects is unclear. Comparison of the three techniques revealed a better correlation between the results obtained with the BATH test and HIC than the results obtained with the BATH and SAT or SAT and HIC. However, these differences may be due to the inaccuracy associated with the visual assessment of results employed by the SAT.

Endodontic 'Solutions'. Part 2:An audit comparing current practice in Belfast with UK and Republic of Ireland Dental Schools

Endodontic lubricants, irrigating solutions and medicaments help reduce the microbial load within root canals. Primary and secondary cases involve different microbes. Each'solution'or combinations thereof could play a significant role but no detailed guidelines exist on their use. An audit was undertaken to compare current practice in Belfast Dental School to the others across the UK and Republic of Ireland (ROI). This audit highlighted three main differences between Belfast and other dental schools. Many other institutions utilized other irrigants besides sodium hypochlorite (NaOCl), different intracanal medicaments, including calcium hydroxide, and higher concentrations of NaOCl. Having gathered this information, we ask, 'Is there sufficient evidence to change the endodontic regime currently used at Belfast Dental School?'. Using the findings from the literature review (Part 1), we introduce new evidence-based protocols for primary and secondary cases for use in Belfast Dental School. Clinical Relevance: In the absence of detailed clinical guidelines on the use of endodontic lubricants, irrigants and medicaments in primary and secondary cases, it is important to be aware of current practice in UK and ROI dental schools where dentists and specialists are trained.

Poly(epsilon-caprolactone) and poly(epsilon-caprolactone)-polyvinylpyrrolidone-iodine blends as ureteral biomaterials: characterisation of mechanical and surface properties, degradation and resistance to encrustation in vitro.

This study describes the physicochemical properties and in vitro resistance to encrustation of solvent cast films composed of either poly(epsilon-caprolactone) (PCL), prepared using different ratios of high (50,000) to low (4000) (molecular weight) m.wt., or blends of PCL and the polymeric antimicrobial complex, poly(vinylpyrrolidone)-iodine (PVP-I). The incorporation of PVP-I offered antimicrobial activity to the biomaterials. Films were characterised in terms of mechanical (tensile analysis, dynamic mechanical thermal analysis) and surface properties (dynamic contact angle analysis, scanning electron microscopy), whereas degradation (at 37degreesC in PBS at pH 7.4) was determined gravimetrically. The resistance of the films to encrustation was evaluated using an in vitro encrustation model. Reductions in the ratio of high:low-m.wt. PCL significantly reduced the ultimate tensile strength, % elongation at break and the advancing contact angle of the films. These effects were attributed to alterations in the amorphous content and the more hydrophilic nature of the films. Conversely, there were no alterations in Young's modulus, the viscoelastic properties and glass-transition temperature. Incorporation of PVP-I did not affect the mechanical or rheological properties of the films, indicative of a limited interaction between the two polymers in the solid state. Manipulation of the high:low m.wt. ratio of PCL significantly altered the degradation of the films, most notably following longer immersion periods, and resistance to encrustation. Accordingly, maximum degradation and resistance to encrustation was observed with the biomaterial composed of 40:60 high:low m.wt. ratios of PCL; however, the mechanical properties of this system were considered inappropriate for clinical application. Films composed of either 50:50 or 60:40 ratio of high:low m.wt. PCL offered an appropriate compromise between physicochemical properties and resistance to encrustation. This study has highlighted the important usefulness of degradable polymer systems as ureteral biomaterials

Dielectronic recombination of He-like to C-like iodine ions

KLL dielectronic recombination resonances, where a free electron is captured into the L shell and at the same time a K shell electron is excited into the L shell, have been measured for open shell iodine ions by measuring the detected yield of escaping ions of various charge states and modeling the charge balance in an electron beam ion trap. In the modeling, the escape from the trap and multiple charge exchange were considered. Extracted ions were used to measure the charge balance in the trap. The different charge states were clearly separated, which along with the correction for artifacts connected with ion escape and multiple charge exchange made the open shell highly charged ion measurements of this type possible for the first time. From the measured spectra resonant strengths were obtained. The results were 4.27(39)x10(-19) cm(2) eV, 2.91(26)x10(-19) cm(2) eV, 2.39(22)x10(-19) cm(2) eV, 1.49(14)x10(-19) cm(2) eV and 7.64(76)x10(-20) cm(2) eV for the iodine ions from He-like to C-like, respectively.

The antimicrobial effects of root canal irrigation and medication

The role of microorganisms in the development and maintenance of pulpal and periapical inflammation have been well documented. The success of root canal treatment largely depends on the elimination of microbial contamination from the root canal system. Although mechanical instrumentation of root canals can reduce bacterial population, effective elimination of bacteria cannot be achieved without the use of antimicrobial root canal irrigation and medication. This review will discuss the antimicrobial effects of the known root canal irrigants and medicaments and explore future developments in the field. © 2007 Mosby, Inc. All rights reserved.

Electrode kinetics and mechanism of iodine reduction in the room-temperature ionic liquid [C(4)mim][NTf2]

The fast electrochemical reduction of iodine in the RTIL 1-butyl-3-methylimidazolium bis(trifluoromethyl-sulfonyl)imide, [C(4)mim][NTf2], is reported and the kinetics and mechanism of the process elucidated. Two reduction peaks were observed. The first reduction peak is assigned to the process

Effects of storage on thermomechanical properties of poly(epsilon-caprolactone) blends containing poly(vinyl pyrrolidone/iodine)

This study reports the effects of: the molecular weight ratio of poly(epsilon -caprolactone) (PCL) in blends containing polymer of high (50 000 g mol(-1)) and low (4000 g mol(-1)) molecular weight; the concentration (0, 1, and 5 wt-%) of poly(vinyl pyrrolidone/iodine) (PVP/I); and storage at 30 degreesC and 75% relative humidity; on the thermomechanical properties of films prepared by solvent evaporation from solutions containing both PCL and PVP/I. The tensile properties were found to be statistically dependent on the molecular weight ratio of PCL but not on the concentration of PVP/I. The reductions in tensile strength and elongation at break associated with increasing amounts of low molecular weight PCL were attributed to a reduction in the concentration of chain entanglements. No changes were observed in viscoelastic properties or the glass transition temperature. Following storage there were no changes in the tensile strength, glass transition temperature, or viscoelastic properties of the films; however, significant reductions in elongation at break were observed. It is suggested that this is due to hydrolytic chain scission of amorphous PCL. Inclusion of 5 wt-% PVP/I increased this process in films containing 100:0 and 80:20 high/low molecular weight PCL (but not 60.40), but the extent of this was small. This study highlighted significant aging properties of PCL in a moist atmosphere. Consequently, it is recommended that suitable packaging materials should be employed to control the exposure of PCL films to water during storage.