To evaluate the morphologic basis of the different outcomes of toluene diisocyanate (TDI) asthma after quitting occupational exposure, we examined ten patients with TDI asthma who showed, at diagnosis, a positive TDI challenge test and nonspecific bronchial hyperresponsiveness (NSBH) to methacholine. After diagnosis, all patients ceased work and a 4- to 40-month follow-up was obtained with thre...

Toluene diisocyanate (TDI), a known human asthmagen, was investigated in skin-sensitized Brown Norway rats for its concentration×time (C×t)-response relationship on elicitation-based endpoints. The major goal of study was to determine the elicitation inhalation threshold dose in sensitized, re-challenged Brown Norway rats, including the associated variables affecting the dosimetry of inhaled TD...

William Meggs's recent article, "Neuro-genic Inflammation and Sensitivity to Environmental chemicals" (EHP 101:234-238), provides a useful introduction to a rapidly growing area of knowledge in physiology and posits a number of interesting hypotheses regarding the health effects of airborne chemicals. Some specific technical points, however, merit comment. Meggs describes the common chemical se...

Chemicals in any form can be safely stored, handled or used if the physical, chemical, and hazardous properties are fully unders tood, and if proper precautions, including the use of adequate safeguards and personal protection equipment, are taken. In this paper , the chemicals to be considered are the g roup of chemicals known as polyisocyanates, a n d the methods of every-day handling of them...

OBJECTIVES To investigate immunological changes in lymph nodes based on expression of cell-specific receptors and cytokine expression profile and accompanying inflammatory reactions in lungs of mice treated with chemicals of known potentials to induce respiratory sensitization and those in which activity in this regard is unclear. MATERIALS AND METHODS On day 1 and 7, Balb/c mice received tol...

The Office of Environmental Health Hazard Assessment (OEHHA) is required to develop guidelines for conducting health risk assessments under the Air Toxics Hot Spots Program (Health and Safety Code Section 44360 (b) (2)). OEHHA developed a Technical Support Document (TSD) in response to this statutory requirement that describes acute, 8 hour and chronic RELs and was adopted in December 2008. The...

Airway hyperresponsiveness to a variety of bronchoconstrictor mediators and physical stimuli, such as exercise, is present in patients with asthma [1]. Inhalation of inflammatory stimuli such as allergens [2] or occupational sensitizing agents [3] in sensitized subjects, the atmospheric pollutant ozone [4], or the development of viral upper respiratory tract infections (5] can cause transient a...

The molecularly imprinted polymer (MIP) based on methacrylic acid functionalized β-cyclodextrin (MAA-β-CD) monomer was synthesized for the purpose of selective recognition of benzylparaben (BzP). The MAA-β-CD monomer was produced by bridging a methacrylic acid (MAA) and β-cyclodextrin (β-CD) using toluene-2,4-diisocyanate (TDI) by reacting the -OH group of MAA and one of the primary -OH groups ...

8.1 Chapter Summary Model trisegmented polyurethanes based on monofunctional polyols, or “monols”, with water-extended toluene diisocyanate (TDI) based hard segments are investigated. The formulations of the materials generated are similar to those of flexible polyurethane foams with the exceptions that the conventional polyol is substituted by an oligomeric monofunctional polyether of ca. 1000...