Little is known of the natural history of thymic carcinoids in multiple endocrine neoplasia type 1 (MEN1). This is important because in 1993 they were identified as a frequent cause of death, yet only small retrospective studies and case reports exist. We report results of a prospective study of 85 patients with MEN1 evaluated for pancreatic endocrine tumors and followed over a mean of 8 yr with serial chest computed tomography, magnetic resonance imaging (MRI), chest x-ray, and, since 1994, octreoscans [somatostatin receptor scintigraphy (SRS)]. Seven patients (8%) developed thymic carcinoids. Patients with and without carcinoids did not differ in clinical, laboratory, or MEN1 tumor features, except for male gender and the presence of a gastric carcinoid. All thymic tumors were hormonally inactive. Four thymic carcinoids lacked 11q loss of heterozygosity, although it was found in three pancreatic endocrine tumors. Computed tomography and/or MRI were more sensitive than SRS or chest x-ray in detecting tumors initially or with recurrence. All patients underwent resection of the thymic carcinoid, and in all patients followed more than 1 yr, the tumor recurred. Bone metastases developed in two patients and were detected early only on MRI, not SRS. This study provides information on early thymic carcinoids and allows modifications of existing guidelines to be recommended for their diagnosis, surveillance, and treatment.

The composition of organic aerosol formed from the gas phase ozonolysis of cyclohexene has been investigated in a smog chamber experiment. Comprehensive gas chromatography with time of flight mass spectrometric detection was used to determine that dicarboxylic acids and corresponding cyclic anhydrides dominated the small gas phase reaction products found in aerosol sampled during the first hour after initial aerosol formation. Structural analysis of larger more polar molecules was performed using liquid chromatography with ion trap tandem mass spectrometry. This indicated that the majority of identified organic mass was in dimer form, built up from combinations of the most abundant small acid molecules, with frequent indication of the inclusion of adipic acid. Trimers and tetramers potentially formed via similar acid combinations were also observed in lower abundances. Tandem mass spectral data indicated dimers with either acid anhydride or ester functionalities as the linkage between monomers. High-resolution mass spectrometry identified the molecular formulae of the most abundant dimer species to be C₁₀H₁₆O₆, C₁₁H₁₈O₆, C₁₀H₁₄O₈ and C₁₁H₁₆O₈ and could be used in some cases to reduce uncertainty in exact chemical structure determination by tandem MS.

This experiment observed the evolution of metabolite plumes from a human trapped in a simulation of a collapsed building. Ten participants took it in turns over five days to lie in a simulation of a collapsed building and eight of them completed the 6 h protocol while their breath, sweat and skin metabolites were passed through a simulation of a collapsed glass-clad reinforced-concrete building. Safety, welfare and environmental parameters were monitored continuously, and active adsorbent sampling for thermal desorption GC-MS, on-line and embedded CO, CO(2) and O(2) monitoring, aspirating ion mobility spectrometry with integrated semiconductor gas sensors, direct injection GC-ion mobility spectrometry, active sampling thermal desorption GC-differential mobility spectrometry and a prototype remote early detection system for survivor location were used to monitor the evolution of the metabolite plumes that were generated. Oxygen levels within the void simulator were allowed to fall no lower than 19.1% (v). Concurrent levels of carbon dioxide built up to an average level of 1.6% (v) in the breathing zone of the participants. Temperature, humidity, carbon dioxide levels and the physiological measurements were consistent with a reproducible methodology that enabled the metabolite plumes to be sampled and characterized from the different parts of the experiment. Welfare and safety data were satisfactory with pulse rates, blood pressures and oxygenation, all within levels consistent with healthy adults. Up to 12 in-test welfare assessments per participant and a six-week follow-up Stanford Acute Stress Response Questionnaire indicated that the researchers and participants did not experience any adverse effects from their involvement in the study. Preliminary observations confirmed that CO(2), NH(3) and acetone were effective markers for trapped humans, although interactions with water absorbed in building debris needed further study. An unexpected observation from the NH(3) channel was the suppression of NH(3) during those periods when the participants slept, and this will be the subject of further study, as will be the detailed analysis of the casualty detection data obtained from the seven instruments used.

A thermal desorption unit has been interfaced to an electrospray ionization-ion mobility-time-of-flight mass spectrometer. The interface was evaluated using a mixture of six model volatile organic compounds which showed detection limits of <1 ng sample loaded onto a thermal desorption tube packed with Tenax, equivalent to sampled concentrations of 4 μg L⁻¹. Thermal desorption profiles were observed for all of the compounds, and ion mobility-mass spectrometry separations were used to resolve the probe compound responses from each other. The combination of temperature programmed thermal desorption and ion mobility improved the response of selected species against background ions. Analysis of breath samples resulted in the identification of breath metabolites, based on ion mobility and accurate mass measurement using siloxane peaks identified during the analysis as internal lockmasses.