Comparative toxicity of methyl isocyanate and its hydrolytic derivatives in rats. II. Pulmonary histopathology in the subacute and chronic phases

Combined association of urinary volatile organic compounds with chronic bronchitis and emphysema among adults in NHANES 2011-2014: The mediating role of inflammation

Evidence on the association of volatile organic compounds (VOCs) with chronic bronchitis (CB) and emphysema is spare and defective. To evaluate the relationship between urinary metabolites of VOCs (mVOCs) with CB and emphysema, and to identify the potential mVOC of paramount importance, data from NHANES 2011-2014 waves were utilized. Logistic regression was conducted to estimate the independent association of mVOCs with respiratory outcomes. Least absolute shrinkage and selection operator (LASSO) regression was performed to screen a parsimonious set of CB- and emphysema-relevant mVOCs that were used for further co-exposure analyses of weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR). Mediation analysis was employed to detect the mediating role of inflammatory makers in such associations. In single exposure analytic model, nine mVOCs were individually and positively associated with CB, while four mVOCs were with emphysema. In WQS regression, positive association between LASSO selected mVOCs and CB was identified (OR = 1.82, 95% CI: 1.25 to 2.69), and N-acetyl-S-(4-hydroxy-2-butenyl)-l-cysteine (MHBMA3) weighted the highest. Results from BKMR further validated such combined association and the significance of MHBMA3. As for emphysema, significantly positive overall trend of mVOCs was only observed in BKMR model and N-acetyl-S-(N-methylcarbamoyl)-l-cysteine (AMCC) contributed most to the mixed effect. White blood cell count (WBC) and lymphocyte number (LYM) were mediators in the positive pattern of mVOCs mixture with CB, while association between mVOCs mixture and emphysema was significantly mediated by LYM and segmented neutrophils num (NEO). This study demonstrated that exposure to VOCs was associated with CB and emphysema independently and combinedly, which might be partly speculated that VOCs were linked to activated inflammations. Our findings shed novel light on VOCs related respiratory illness, and provide a new basis for the contribution of certain VOCs to the risk of CB and emphysema, which has potential public health implications.

Emerging role of metabolomics in rheumatology

The pursuit for understanding disease pathogenesis, in this age of rapid laboratory diagnostics and fast-paced research, has led scientists worldwide to take recourse in hypothesis-free approaches for molecular diagnosis. Metabolomics is one such powerful tool that explores comprehensibly the metabolic alternations in human diseases. It involves study of small molecules of less than 1 kD in size by either LSMS or nuclear magnetic resonance. Unlike genomics, which tells us what may have happened, metabolomics reflects what did happen. The NMR technique has an advantage of analyzing metabolites without sample preparation, thereby diminishing artifacts, is less cumbersome and with the latest database on Metabolome; about 30 000 metabolites can be identified. The study of metabolomics for several rheumatic diseases, including rheumatoid arthritis, lupus, osteoarthritis and vasculitis, has revealed distinctive metabolic signatures. Thus, metabolomics is a technique that promises precision medicine with better biomarkers, robust predictors of drug response and of disease outcome, discovery of newer metabolites and pathways in disease pathogenesis, and finally, targeted drug development. This review intends to decipher its relevance in common rheumatic diseases.

A randomized trial of amifostine and carmustine-containing chemotherapy to assess lung-protective effects

We conducted a randomized, double blind, placebo-controlled multi-institutional trial to assess the ability of amifostine to protect patients against acute lung injury associated with cyclophosphamide/cisplatin/carmustine (BCNU) (STAMP I), a BCNU-containing high dose chemotherapy regimen used with hematopoietic cell transplantation. Amifostine was administered in a dose of 740 mg/m(2) for 2 doses preceding administration of BCNU, the presumed pulmonary-toxic component of the regimen. The trial was stopped after 79 patients were randomized and a planned interim analysis demonstrated that it was unlikely that pulmonary cytoprotection would be detected with further accrual. We conclude that amifostine, used in the dose and schedule we tested, does not reduce the incidence of acute lung injury produced by STAMP I. Further, we suggest that amifostine use with BCNU in other contexts and with clinically achievable doses is unlikely to protect the lung from BCNU-associated acute injury.

Inhalation toxicity of tetramethylurea in rats

Tetramethylurea (TMU, CAS No. 632-22-4) was tested for its inhalation toxicity in rats following repeated exposures. Male rats were exposed whole-body to TMU for 6 hours/day, 5 days/week for a total of 9 exposures over 2 weeks. Concentrations of 0 (control), 2, 20, and 100 ppm were studied. Four groups of 10 rats each were used to measure clinical signs and growth, clinical pathology (including hematology, biochemistries, and urine analysis), and tissue pathology. One-half of the rats were sacrificed 1 day following the 9th exposure; the other half underwent an 18-day recovery period prior to being sacrificed (recovery group). Body weight gains in rats exposed to 100 ppm were reduced as compared to the controls; no body weight effects were seen in either 2 or 20 ppm rats and no clinical signs of toxicity were observed in rats at any of the levels throughout the study. No compound-related clinical pathology changes were seen in any of the test groups and tissue pathology effects only occurred in the nasal tissue. In rats exposed to 100 ppm, microscopic observations of degeneration, necrosis, and ulceration of olfactory mucosa was seen. These lesions were still present but seen as recovering and healing after the 18-day recovery. Under the conditions of this test, the no-observed-adverse-effect level (NOAEL) was determined to be 20 ppm based upon both body weight changes and upper respiratory tract pathologic changes in 100 ppm rats.