Gas chromatography-mass spectrometry methods for analysis of 2- and 3-hydroxylated fatty acids: Application for endotoxin measurement

Mielniczuk, Zbigniew; Mielniczuk, Eugenia; Larsson, Lennart

doi:10.1016/0167-7012(93)90002-y

Cited by 66 publications

(58 citation statements)

References 12 publications

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“…Preparation of dust samples for 3-OHFA analysis was done essentially as described previously (16). Briefly, samples were hydrolyzed with 4 M methanolic HCl at 100°C for 18 h, methyl esters of the released fatty acids were extracted with heptane, nonhydroxylated esters were separated from hydroxylated esters by using a silica gel column, and finally, hydroxylated fatty acid esters were derivatized with N,O-bis-(trimethylsilyl)trifluoroacetamide and pyridine to form trimethylsilyl derivatives.…”

Section: Methodsmentioning

confidence: 99%

“…Briefly, samples were hydrolyzed with 4 M methanolic HCl at 100°C for 18 h, methyl esters of the released fatty acids were extracted with heptane, nonhydroxylated esters were separated from hydroxylated esters by using a silica gel column, and finally, hydroxylated fatty acid esters were derivatized with N,O-bis-(trimethylsilyl)trifluoroacetamide and pyridine to form trimethylsilyl derivatives. The derivatized 3-OHFAs were analyzed by selected ion monitoring of m/z 175 and m/z (M-15) (16,26); deuterated 3-OH C 14 was used as an internal standard (monitoring m/z 178). The amount of LPS (nanomoles) was calculated as the sum of the number of nanomoles of 3-OHFAs over all measured carbon chain lengths divided by four.…”

Section: Methodsmentioning

confidence: 99%

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Characterization of Lipopolysaccharides Present in Settled House Dust

Park

Szponar

Larsson

et al. 2004

Appl Environ Microbiol

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The 3-hydroxy fatty acids (3-OHFAs) in lipopolysaccharides (LPS) play an important role in determining endotoxin activity, and childhood exposure to endotoxin has recently been associated with reduced risk of atopic diseases. To characterize the 3-OHFAs in house dust (HD), we used gas chromatography-mass spectrometry to assay 190 HD samples. Dust from beds, bedroom floors, family rooms, and kitchen floors was collected as part of a birth cohort study of childhood asthma (study 1) and a longitudinal study of home allergen and endotoxin (study 2). We also measured endotoxin activity with a Limulus assay and computed specific activity (endotoxin activity per nanomole of LPS). Longer-chain (C 16:0 and C 18:0 ) 3-OHFAs were predominant in HD compared with short-chain (C 10:0 , C 12:0 , and C 14:0 ) acids. Endotoxin activity was positively correlated with short-chain 3-OHFAs in both studies. In study 2, 3-OH C 16:0 was negatively correlated and 3-OH C 18:0 was not correlated with endotoxin activity, consistent with previous findings that the Limulus assay responds preferentially to LPS containing short-chain 3-OHFAs. Kitchen dust contained the highest concentrations of 3-OH C 10:0 , the highest endotoxin activities, and the highest specific activities (P < 0.03). Bed dust contained the largest amounts of long-chain 3-OHFAs, the highest concentrations of LPS, and the lowest specific activities. Apartments had significantly different types of LPS (P ‫؍‬ 0.03) compared with single-family homes in study 2. These data suggest that the Limulus assay may underestimate exposure to certain types of LPS. Because nontoxic LPS may have immune modulating effects, analysis of 3-OHFAs may be useful in epidemiologic studies.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Characterization of Lipopolysaccharides Present in Settled House Dust

Park

Szponar

Larsson

et al. 2004

Appl Environ Microbiol

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“…20 Analysis was performed on a VG Trio-1S GC-MS with a Hewlett-Packard model 5890 GC, 7673 autosampler, and an OV-1 fused-silica capillary column (J&W Scientific). Samples were ionized in electron impact mode and analyzed using selected ion monitoring.…”

Section: Pg and Lpsmentioning

confidence: 99%

“…14,[19][20][21][22] Endotoxin activity is measured biologically by the Limulus amoebocyte lysate (LAL) clotting assay. [23][24][25] LPS can differ in biological activity depending on the source.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the Concentration of Bacteria and Their Cell Envelope Components in Indoor Air in Two Elementary Schools

Liu

Krahmer

Fox

et al. 2000

Journal of the Air & Waste Management Association

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Bacterial cell envelope components are widely distributed in airborne dust, where they act as inflammatory agents causing respiratory symptoms. Measurements of these agents and other environmental factors are assessed in two elementary schools in a southeastern city in the United States. Muramic acid (MA) was used as a marker for bacterial peptidoglycan (PG), and 3-hydroxy fatty acids (3-OH FAs) were used as markers for Gram-negative bacterial lipopolysaccharide (LPS). Culturable bacteria were collected using an Andersen sampler with three different culture IMPLICATIONS Levels of bacteria and their constituents (PG and LPS) are correlated with total surface dust and TSP levels in school environments. This suggests an important environmental health guideline for school administrators: decreasing both surface dust and TSP levels will likely reduce potential exposure to harmful biocontaminants. The high correlations between CO 2 and levels of bacteria and their constituents also indicate that an appropriate air-exchange rate may help minimize biocontamination. The analytical MA and 3-OH FA methods measure culturable and nonculturable bacteria as well as bacterial cell wall remnants, whereas the culture method only assesses the culturable portion of the bacterial population. Together, these three different measures provide complementary information for characterizing biocontamination of indoor air, which is more informative than information provided by culture alone. Additional evaluation of other environmental factors, including CO 2 and air-exchange rate, might suggest recommendations for lowering biocontamination in buildings.media. In addition, temperature (T), relative humidity (RH), and CO 2 were continuously monitored.Concentrations of airborne MA and 3-OH FAs were correlated with total suspended particulate (TSP) levels. Outdoor MA (mean = 0.78-1.15 ng/m 3 ) and 3-OH FA levels (mean = 2.19-2.18 ng/m 3 ) were similar at the two schools. Indoor concentrations of airborne MA and 3-OH FAs differed significantly between schools (MA: 1.44 vs. 2.84 ng/m 3 ; 3-OH FAs: 2.96 vs. 4.57 ng/m 3 ). Although indoor MA levels were low, they were significantly related to teachers' perception of the severity of indoor air quality (IAQ) problems in their classrooms. Concentrations of CO 2 correlated significantly with all bacteria measurements. Because CO 2 levels were related to the number of occupants and the ventilation rates, these findings are consistent with the hypothesis that the children and teachers are sources of bacterial contamination. Many culturable bacteria present in indoor air are opportunistic organisms that can be infectious for compromised individuals, while both culturable and nonculturable bacterial remnants act as environmental toxins for both healthy and compromised individuals. Measuring the "total bacteria load" would be most accurate in assessing the biotoxicity of indoor air. Chemical analysis of MA and 3-OH FAs, when coupled with the conventional culture method, provides complementary infor...

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“…The number of 3-OH fatty acid moles was, therefore, divided by 4 and multiplied by 8,000 to give an estimate of the LPS weight. Analysis of 3-OH fatty acid was then performed as described previously [20]. The aqueous (acidic) phase was evaporated, subjected to TMS derivatization, and analysed for muramic acid [21].…”

Section: Exposure Measurementsmentioning

confidence: 99%

Inhalation of swine dust induces cytokine release in the upper and lower airways

Larsson²,

Palmberg³

et al. 1997

Eur Respir J

144

138

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In healthy subjects, acute inhalation of swine dust causes an influx of inflammatory cells into the airways and increased bronchial responsiveness. The exposure may also cause fever and generalized symptoms. It seems likely that proinflammatory cytokines are involved in the response to inhaled swine dust.Nasal and bronchoalveolar lavage (BAL) were performed before, and 7 and 24 h after the start of 3 h exposure to swine dust, during a period of work in a swine confinement building, in 22 healthy subjects. Lavage fluids were analysed with regard to the cellular response and concentrations of interleukin (IL)-1α, IL-1β, IL-6 and tumour necrosis factor-α (TNF-α). Each subject carried personal samplers for exposure measurements. Inhalable dust and airborne endotoxin, 3-hydroxylated (2-OH) fatty acid and muramic acid were measured. Bronchial responsiveness to methacholine was investigated 1-2 weeks before and 7 h after the start of the exposure.Exposure caused fever (>38°C) in three subjects, and approximately 25% of the subjects experienced symptoms. Bronchial responsiveness to methacholine increased by 3.5 (1.6-4.8) doubling doses (median (25th-75th percentile)). Following exposure, granulocytes increased more than 50 fold in BAL fluid and more than 40 fold in nasal lavage fluid. IL-1α and IL-1β increased significantly in BAL fluid (p<0.05) and nasal lavage fluid (p<0.01). IL-6 increased 25 fold in BAL and 15 fold in nasal lavage fluid (p<0.001). TNF-α was below detection limit (0.25 ng·L -1 ) in most subjects before exposure and increased following exposure to 3.8 (2.4-5.7) and 1.3 (0.6-2.3) ng·L -1 in BAL and nasal lavage fluid, respectively, (p<0.001). Total inhalable dust was 20.5 (14.6-30.0) mg·m -3 and the concentrations of airborne endotoxin, 3-OH fatty acid and muramic acid were 1.2 (0.8-1.4), 3.5 (2.2-4.5) and 0.9 (0.3-1.9) µg·m -3 , respectively. There was a significant correlation between the IL-6 response in BAL fluid and exposure to dust endotoxin activity and 3-OH fatty acids (p<0.05). Otherwise, no significant correlations were found between exposure and the cytokine response.We conclude that exposure to swine dust causes an intense upper and lower airway inflammation, which involves the proinflammatory cytokines interleukin-1, interleukin-6 and tumour necrosis factor-α.

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Gas chromatography-mass spectrometry methods for analysis of 2- and 3-hydroxylated fatty acids: Application for endotoxin measurement

Cited by 66 publications

References 12 publications

Characterization of Lipopolysaccharides Present in Settled House Dust

Characterization of Lipopolysaccharides Present in Settled House Dust

Investigation of the Concentration of Bacteria and Their Cell Envelope Components in Indoor Air in Two Elementary Schools

Inhalation of swine dust induces cytokine release in the upper and lower airways

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