Examining factors that influence the effectiveness of cleaning antineoplastic drugs from drug preparation surfaces: a pilot study.

Occupational exposure to antineoplastic drugs has been documented to result in various adverse health effects. Despite the implementation of control measures to minimize exposure, detectable levels of drug residual are still found on hospital work surfaces. Cleaning these surfaces is considered as one means to minimize the exposure potential. However, there are no consistent guiding principles related to cleaning of contaminated surfaces resulting in hospitals to adopt varying practices. As such, this pilot study sought to evaluate current cleaning protocols and identify those factors that were most effective in reducing contamination on drug preparation surfaces. Three cleaning variables were examined: (1) type of cleaning agent (CaviCide®, Phenokil II™, bleach and chlorhexidine), (2) application method of cleaning agent (directly onto surface or indirectly onto a wipe) and (3) use of isopropyl alcohol after cleaning agent application. Known concentrations of antineoplastic drugs (either methotrexate or cyclophosphamide) were placed on a stainless steel swatch and then, systematically, each of the three cleaning variables was tested. Surface wipes were collected and quantified using high-performance liquid chromatography-tandem mass spectrometry to determine the percent residual of drug remaining (with 100% being complete elimination of the drug). No one single cleaning agent proved to be effective in completely eliminating all drug contamination. The method of application had minimal effect on the amount of drug residual. In general, application of isopropyl alcohol after the use of cleaning agent further reduced the level of drug contamination although measureable levels of drug were still found in some cases.

Pilot assessment of the antineoplastic drug contamination levels in British Columbian hospitals pre- and post-cleaning.

OBJECTIVE: We undertook a pilot study involving six British Columbian hospital pharmacies to determine if antineoplastic drug contamination of surfaces exists and whether residual drugs remain on these surfaces despite being cleaned. METHODS: At each site, the pharmacy technician responsible for preparing the antineoplastic drugs was observed to determine which surfaces were contacted and to ascertain the frequency of contact. Surfaces observed to be most frequently contacted were subsequently wiped after drug preparation pre- and post-clean. The wipe samples were then analyzed by liquid chromatography tandem mass spectrometry to determine the amount of contamination. Cyclophosphamide (CP) and methotrexate (MTX) were used as representative markers to reflect overall antineoplastic drug contamination levels. RESULTS: Fourteen of the 23 surfaces sampled pre-clean (61%) were contaminated with either MTX or CP. The pre-clean wipe samples had a geometric mean concentration of 0.0135 ng/cm(2) for MTX (range

Occupational Exposure to Antineoplastic Drugs: Identification of Job Categories Potentially Exposed throughout the Hospital Medication System.

OBJECTIVES: Studies examining healthcare workers' exposure to antineoplastic drugs have focused on the drug preparation or drug administration areas. However, such an approach has probably underestimated the overall exposure risk as the drugs need to be delivered to the facility, transported internally and then disposed. The objective of this study is to determine whether drug contamination occurs throughout a facility and, simultaneously, to identify those job categories that are potentially exposed. METHODS: This was a multi-site study based in Vancouver, British Columbia. Interviews were conducted to determine the departments where the drugs travel. Subsequent site observations were performed to ascertain those surfaces which frequently came into contact with antineoplastic drugs and to determine the job categories which are likely to contact these surfaces. Wipe samples were collected to quantify surface contamination. RESULTS: Surface contamination was found in all six stages of the hospital medication system. Job categories consistently found to be at risk of exposure were nurses, pharmacists, pharmacy technicians, and pharmacy receivers. Up to 11 job categories per site may be at risk of exposure at some point during the hospital medication system. CONCLUSION: We found drug contamination on select surfaces at every stage of the medication system, which indicates the existence of an exposure potential throughout the facility. Our results suggest that a broader range of workers are potentially exposed than has been previously examined. These results will allow us to develop a more inclusive exposure assessment encompassing all healthcare workers that are at risk throughout the hospital medication system.

UV induces GADD45 in a p53-dependent and -independent manner in human keratinocytes.

BACKGROUND: GADD45 is a multifunctional protein involved in DNA repair and in cell cycle checkpoint control. p53 plays an important role in regulating DNA repair and in response to UVB in keratinocytes. OBJECTIVE: GADD45 and p53 expression was examined and compared at the mRNA and protein level after exposure to UV irradiation. METHODS: Human keratinocytes were exposed to increasing doses of UVB, and an RNA protection assay and a Western blot analysis were performed. RESULTS: The RNase protection assays using human keratinocytes showed that GADD45 mRNA increases after 4 h and remains elevated for 24 h in cells irradiated at 100, 300, or 600 J/m2 UVB. The level of GADD45 protein increases after 8 h and remains elevated for 48 h, with maximal induction at 300 J/m2. p53 mRNA did not rise in concert with GADD45 at any dose used, and p53 protein was not up-regulated at the lower dose of 100 J/m2. CONCLUSION: GADD45 is regulated in both a p53-dependent and a p53-independent manner in keratinocytes after UV exposure.

GADD45 regulates G2/M arrest, DNA repair, and cell death in keratinocytes following ultraviolet exposure.

GADD45 is a multifunctional protein that is regulated by p53. p53 plays an important role in regulating DNA repair and in the response to ultraviolet light in keratinocytes. This study investigates the role of GADD45 in the response to ultraviolet B. Cell cycle analysis demonstrated that wild-type and Gadd45-deficient cells have transient G2/M arrest, but only in the wild-type cells was arrest sustained. Cdc2 kinase activity in immunoprecipitates from normal and Gadd45-deficient cells decreases after irradiation in normal cells but not in Gadd45-deficient cells. An immunofluorescent study with Cdc2 antibody demonstrated diffuse cellular fluorescence before ultraviolet irradiation in both Gadd45-deficient and wild-type cells, but upon ultraviolet irradiation only Gadd45-proficient cells showed Cdc2 sequestration in the cytoplasm. Gadd45-deficient cells also have a slower rate of nucleotide excision repair. The lack of G2/M arrest coupled with reduced DNA repair leads to a higher ultraviolet sensitivity of Gadd45-deficient cells. These results reveal that GADD45 promotes G2/M arrest via nuclear export and kinase activity of Cdc2, increases global genomic DNA repair, and inhibits cell death in keratinocytes. Thus, GADD45 plays an important role in maintaining genomic integrity in ultraviolet-exposed skin.

Role of p21(Waf-1) in regulating the G1 and G2/M checkpoints in ultraviolet-irradiated keratinocytes.

This study examines the role of p21(Waf-1) , a p53-dependent protein, in regulating mechanisms that protect keratinocytes against ultraviolet-B-induced cellular damage. Keratinocytes from p21(Waf-1) or p53-deficient mice were irradiated with ultraviolet B, and examined for DNA repair, cell cycle progression, and cell death. Both p21(Waf-1) -deficient and p53-deficient cells failed to maintain G2 arrest, and p21(Waf-1) -deficient cells, and to a lesser extent p53-deficient cells, also failed to undergo G1 arrest. After exposure to ultraviolet B, p53-deficient cells were more susceptible to cell death than wild-type cells. p21(Waf-1) -deficient cells did not undergo apoptotic cell death more often, however, but did have an increased frequency of nuclear abnormalities, suggesting mitotic catastrophe. TUNEL assay showed DNA fragmentation in the p53 +/+, p21(Waf-1) +/+, and p53 -/- cells, but not in p21(Waf-1) -/- cells. This result is consistent with the suggestion that p21(Waf-1) -deficient keratinocytes undergo mitotic cell death (catastrophe) after exposure to ultraviolet B irradiation in the system. Western analysis demonstrated that p21(Waf-1) expression was upregulated in p53-proficient and -deficient keratinocytes, supporting the notion that a p53-independent mechanism contributes to the response to ultraviolet B in keratinocytes. Finally, p21(Waf-1) -deficient cells had slightly less efficient nucleotide excision repair. In summary, this study suggests that p21(Waf-1) regulates the ultraviolet-B-induced G2/M checkpoint through p53, and the G1 checkpoint partially through p53. p21(Waf-1) does not significantly regulate DNA repair in ultraviolet-irradiated keratinocytes, however.