Honing-in antigen-specific cells during antibody discovery: a user-friendly process to mine a deeper repertoire.

Immunization based antibody discovery is plagued by the paucity of antigen-specific B cells. Identifying these cells is akin to finding needle in a haystack. Current and emerging technologies while effective, are limited in terms of capturing the antigen-specific repertoire. We report on the bulk purification of antigen-specific B-cells and the benefits it offers to various antibody discovery platforms. Using five different antigens, we show hit rates of 51-88%, compared to about 5% with conventional methods. We also show that this purification is highly efficient with loss of only about 2% antigen specific cells. Furthermore, we compared clones in which cognate chains are preserved with those from display libraries in which chains either from total B cells (TBC) or antigen-specific B cells (AgSC) underwent combinatorial pairing. We found that cognate chain paired clones and combinatorial clones from AgSC library had higher frequency of functional clones and showed greater diversity in sequence and paratope compared to clones from the TBC library. This antigen-specific B-cell selection technique exemplifies a process improvement with reduced cycle time and cost, by removing undesired clones prior to screening and increasing the chance of capturing desirable and rare functional clones in the repertoire.

An updated hazard communication standard.

Knowledge about chemical dangers is essential to nurses' safety.

The risks and benefits of chemical fumigation in the health care environment.

Fumigation of hospital rooms with high concentrations of toxic chemicals has been proposed to reduce microbial agents on hospital surfaces and to control infections. Chemical fumigation has been used effectively in other areas, such as building decontamination after bioterrorism events, in agriculture, and in residential structures. However, even in these situations, there have been incidents where fumigants have escaped, causing illness and death to exposed workers and the public. Before expanding the use of a potentially hazardous technology in areas where there are vulnerable individuals, it is important to fully weigh benefits and risks. This article reviews the effectiveness of fumigation as a method of inactivating microbes on environmental surfaces and in reducing patient infection rates against the potential risks. Peer-reviewed literature, consensus documents, and government reports were selected for review. Studies have demonstrated that fumigation can be effective in inactivating microbes on environmental surfaces. However, the current consensus of the infection control community is that the most important source of patient infection is direct contact with health care workers or when patients auto-infect themselves. Only one peer-reviewed, before-after study, at one hospital reported a significant reduction in infection rates following chemical fumigation. The limitations of this study were such that the authors acknowledged that they could not attribute the rate reduction to the fumigation intervention. A serious concern in the peer-reviewed literature is a lack of evidence of environmental monitoring of either occupational or non-occupational exposures during fumigation. Currently, there are neither consensus documents on safe fumigation exposure levels for vulnerable bedridden patients nor sampling methods with an acceptable limit of detection for this population. Until additional peer-reviewed studies are published, demonstrating significant reductions in patient infection rates following chemical fumigation and consensus guidance on the safe exposure levels and monitoring methods, chemical fumigation in health care should be conducted only in the most stringently controlled research settings.

Pollution prevention--occupational safety and health in hospitals: alternatives and interventions.

An integrated pollution prevention (P(2)) and occupational safety and health (OSH) worksite intervention and alternatives assessment strategy was developed in hospitals. It was called the Pollution Prevention-Occupational Safety and Health (P(2)OSH) assessment for the "Sustainable Hospitals Project." Methods included (a) developing a participatory intervention model for introducing more environmentally sound, healthy, and safe materials and work practices for specific hospital procedures; (b) developing an integrated P(2)OSH survey to evaluate environmental and occupational impacts of the intervention; and (c) conducting and evaluating interventions by applying the P(2)OSH assessment pre- and post-intervention. Eleven interventions were performed in six hospitals: an aliphatic fixative replaced xylene in three histology laboratories; a mercury reduction plan was implemented in three clinical laboratories; digital imaging replaced wet chemical film processing in three radiology departments; a less toxic aldehyde replaced formaldehyde in one hospital histopathology laboratory; and conventional mopping was replaced by microfiber mopping in one hospital. Occupational and environmental health and safety impacts were observed for all interventions. The alternatives generally were beneficial, although each had limitations that resulted in process and task changes with potentially negative P(2) and/or OSH impacts. When these were identified in the pilot phase they could be addressed before full-scale implementation. The P(2)OSH method shifts the focus of occupational and environmental hygiene from hazard control to substitution. Because few ideal alternatives exist, the emphasis is on a continuous process to identify, implement, and evaluate alternatives, rather than on a particular alternative. Occupational and environmental health and safety professionals have an important role as agents in hospital organizational change and in the search for healthier and safer alternatives. Through these activities they can become involved in the design/redesign of products, materials, and processes, thus expanding their traditional role.