Can household dishwashers be used to disinfect medical equipment?

In hospitals, medical instruments are usually cleaned and disinfected in a washer/disinfector. However, it is not efficient for small hospitals or general practitioners to purchase such machines as they would not be working to capacity. We investigated the possibility of cleaning and disinfecting medical equipment in a conventional household dishwasher modified to achieve a temperature of 71 degrees C. For this purpose we contaminated screws with different test soils containing either bacterial (100 screws) or viral (106 screws) suspensions. Test organisms were re-isolated from 2% of the screws after bacterial contamination and 4.7% of those with viral contamination. In both cases we found dishwasher-processing to be a suitable means of disinfecting medical instruments.

Analysis of benzalkonium chloride in the effluent from European hospitals by solid-phase extraction and high-performance liquid chromatography with post-column ion-pairing and fluorescence detection.

A highly reproducible and specific method for the analysis of the quaternary ammonium compound, benzalkonium chloride, in effluents from European hospitals is presented. Benzalkonium chloride was extracted with end-capped RP-18 solid-phase cartridges and was selectively eluted. The resulting solution was analyzed by high-performance liquid chromatography (HPLC). After elution from the analytical column of the HPLC system, 9,10-dimethoxyanthracene-2-sulfonate was added continuously as a fluorescence marker, forming a hydrophobic ion-pair with benzalkonium chloride. The ion-pair was analyzed by fluorescence detection. The method was applied to highly complex effluent samples from different sized European hospitals. The measured concentrations were between 0.05 and 6.03 mg/l. The amounts emitted per bed and year were 4.5-362 g and did not correlate with the size of the hospital. The total amounts were 2.6-909 kg/year.

Sample and probe: a novel approach for identifying development-specific cis-elements of the enkephalin gene.

We have developed a novel 'sample and probe' approach as a means to identifying specific DNA elements of the enkephalin gene that control differentiation of the enkephalinergic phenotype during neurodevelopment. The approach is a systematic spatiotemporal analysis of protein-DNA interactions; soluble nuclear proteins ('samples') prepared from microdissected regions of the developing brain are 'probed' with radiolabeled DNA fragments representing various regulatory regions of the enkephalin gene. The resulting spatiotemporal 'molecular maps', i.e. characteristic patterns of protein-DNA complexes showed DNA regions that harbor potential cis-elements regulating differentiation of the enkephalin phenotype at various stages of neurodevelopment. DNase I footprint analysis of such a DNA region identified a binding site (GACGGGAGATCGCTCGT) which is similar to the motif for a lymphoid-specific, developmentally regulated transcription factor, Ikaros, suggesting that the developing brain expresses Ikaros-like transcription factor(s) in a spatiotemporally defined manner. In summary, our approach offers a unique view into the chronology of coordinated protein-DNA interactions and will greatly facilitate identifying DNA elements and isolating development-specific transcription factors.