No abstract

The aim of this study is to explore how differences in cigarette physical design parameters influence tar, nicotine, and carbon monoxide (TNCO) yields in mainstream smoke (MSS) using the International Organization of Standardization (ISO) smoking regimen. Standardized smoking methods were used to evaluate 50 U.S. domestic brand cigarettes and a reference cigarette representing a range of TNCO yields in MSS collected from linear smoking machines using a nonintense smoking regimen. Multivariate statistical methods were used to form clusters of cigarettes based on their ISO TNCO yields and then to explore the relationship between the ISO generated TNCO yields and the nine cigarette physical design parameters between and within each cluster simultaneously. The ISO generated TNCO yields in MSS are 1.1–17.0 mg tar/cigarette, 0.1–2.2 mg nicotine/cigarette, and 1.6–17.3 mg CO/cigarette. Cluster analysis divided the 51 cigarettes into five discrete clusters based on their ISO TNCO yields. No one physical parameter dominated across all clusters. Predicting ISO machine generated TNCO yields based on these nine physical design parameters is complex due to the correlation among and between the nine physical design parameters and TNCO yields. From these analyses, it is estimated that approximately 20% of the variability in the ISO generated TNCO yields comes from other parameters (e.g., filter material, filter type, inclusion of expanded or reconstituted tobacco, and tobacco blend composition, along with differences in tobacco leaf origin and stalk positions and added ingredients). A future article will examine the influence of these physical design parameters on TNCO yields under a Canadian Intense (CI) smoking regimen. Together, these papers will provide a more robust picture of the design features that contribute to TNCO exposure across the range of real world smoking patterns.

Proteomics analysis of bovine bronchoalveolar fluid (BAF) following induction of pneumonia with Mannheimia haemolytica using nanoflow liquid chromatography coupled with tandem mass spectrometry (nanoLC-MS/MS) resulted in the identification of 88 unique proteins. Proteins detected in BAF included antimicrobial peptides (AMPs), complement factors, acute-phase proteins, protease inhibitors, and proteins involved in oxidation-reduction. Notwithstanding biological variation, differences in relative protein abundance, determined using normalized peptide counts, were detected for select proteins in BAF from genuinely infected versus sham-infected animals. To demonstrate the applicability of using normalized peptide counts to assess protein expression trends, LC-MS/MS data for the acute-phase protein haptoglobin (HPT) were compared with ELISA data, and statistical evaluation of the relationship between the data revealed a strong measure of association. Differences were detected between sham- and genuinely infected animals for haptoglobin, as well as the AMPs cathelicidin-1 and cathelicidin-4, and inter-α-trypsin inhibitor heavy chain-4, a fairly novel protein involved in the acute phase response. Though the small sample size limited the scope of the inferences, the results indicate the likely importance of AMPs and acute-phase proteins during respiratory infection, and provide additional information regarding potential mechanisms involved in the bovine mucosal barrier defense.

Ceftiofur is a widely used cephalosporin β-lactam antibiotic with frequently reported residue violations. This paper reports a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determining a ceftiofur metabolite, desfuroylceftiofur cysteine disulfide (DCCD), in bovine kidney, liver, and muscle tissues. Incurred tissue samples were obtained from dosed animals and analyzed to evaluate the utility of the method. For kidney, the target tissue, the method utilized a simple extraction with phosphate buffer followed by solid phase extraction (SPE) cleanup. For liver and muscle, acetonitrile and hexane were used to remove most proteins and fat from the initial buffer extract before the SPE cleanup. Method accuracy was between 97 and 107%, and the coefficient of variation was between 3.4 and 11.0% for all three types of tissues. The relationship between the new and regulatory methods for bovine kidney was established. It was concluded that DCCD is a suitable surrogate marker residue for ceftiofur in bovine kidney.