Tom Deutschle

A Controlled Challenge Study on Di(2-ethylhexyl) Phthalate (DEHP) in House Dust and the Immune Response in Human Nasal Mucosa of Allergic Subjects

Background Few studies have yet addressed the effects of di(2-ethylhexyl) phthalate (DEHP) in house dust on human nasal mucosa. Objectives We investigated the effects of house dust containing DEHP on nasal mucosa of healthy and house dust mite (HDM)–allergic subjects in a short-term exposure setting. Methods We challenged 16 healthy and 16 HDM-allergic subjects for 3 hr with house dust at a concentration of 300 μg/m3 containing either low (0.41 mg/g) or high (2.09 mg/g) levels of DEHP. Exposure to filtered air served as control. After exposure, we measured proteins and performed a DNA microarray analysis. Results Nasal exposure to house dust with low or high DEHP had no effect on symptom scores. Healthy subjects had almost no response to inhaled dust, but HDM-allergic subjects showed varied responses: DEHPlow house dust increased eosinophil cationic protein, granulocyte-colony–stimulating factor (G-CSF), interleukin (IL)-5, and IL-6, whereas DEHPhigh house dust decreased G-CSF and IL-6. Furthermore, in healthy subjects, DEHP concentration resulted in 10 differentially expressed genes, whereas 16 genes were differentially expressed in HDM-allergic subjects, among them anti-Müllerian hormone, which was significantly up-regulated after exposure to DEHPhigh house dust compared with exposure to DEHPlow house dust, and fibroblast growth factor 9, IL-6, and transforming growth factor-β1, which were down-regulated. Conclusions Short-term exposure to house dust with high concentrations of DEHP has attenuating effects on human nasal immune response in HDM-allergic subjects, concerning both gene expression and cytokines.

Nasal toxicity of benzalkonium chloride.

Background Benzalkonium chloride (BAC) is added to nasal preparations to prevent microbial contamination. Adverse effects of BAC on human nasal mucosa should be evaluated. Methods The ciliotoxicity of BAC was assessed in isolated human nasal epithelia from 15 donors. The effects of nasal BAC 0.05% (4 X 200 μL/day for 8 days) on nasal saccharin transport time, inflammatory cells and cytokine levels in nasal secretions, and nasal symptom scores were assessed in a randomized, double-blind crossover trial in 16 healthy volunteers. Results In vitro, BAC was ciliotoxic (p < 0.0001). In vivo, BAC did not alter saccharin transport time in healthy individuals (p > 0.8). No BAC-associated proinflammatory effects were observed. The staining index for myeloperoxidase was 4.8% in the placebo period and 6.3% (p = 0.42) in the BAC period. Also, nasal secretion levels of cytokines and the neuropeptide substance P revealed no BAC-associated differences. Concentrations for interleukin (IL)-6 in the placebo period were 41.5 pg/mL (0.9–91.7 pg/mL) and in the BAC period were 17.6 pg/mL (3.2–65.9 pg/mL; p = 0.46), and concentrations for substance P were 119 pg/mL (58–293 pg/mL) and 131 pg/mL (80–330 pg/mL; p = 0.31), respectively. Immediately after application, BAC caused nasal irritation (p = 0.001), a burning sensation (p = 0.0003), and hypersecretion (p = 0.006). Moreover, BAC caused a persistent sensation of nasal irritation (p < 0.01). Conclusion BAC in concentrations used in nasal preparations is ciliotoxic. In healthy individuals, the ciliotoxic effect of BAC is neutralized, probably by components of nasal secretions. No BAC-related proinflammatory effects have been observed. At higher doses than normally used therapeutically, BAC caused significant nasal irritation. (American Journal of Rhinology 18, 291–299, 2004)

Differential Response of Mono Mac 6, BEAS-2B, and Jurkat Cells to Indoor Dust

Background Airway toxicity of indoor dust is not sufficiently understood. Objectives Our goal in this study was to describe the effects of indoor dust on human monocyte, epithelial, and lymphocyte cell lines. We aimed to a) obtain a comprehensive and intelligible outline of the transcriptional response; b) correlate differential transcription with cellular protein secretion; c) identify cell line–specific features; and d) search for indoor dust–specific responses. Methods Settled dust was sampled in 42 German households, and various contaminants were characterized. We exposed Mono Mac 6, BEAS-2B, and Jurkat cells to 500 μg/mL indoor dust for 6 hr. Outcome parameters included the transcriptional profile of an oligonucleotide microarray covering 1,232 genes. Significantly enriched Gene Ontology themes were calculated. Supernatant protein levels of 24 inflammatory response proteins served to confirm transcriptional results. Results An intraclass correlation coefficient of 0.8 indicated reasonable microarray reproducibility. The transcriptional profile was characterized by enhancement of detoxification and a danger and defense response. Differential gene regulation correlated with protein secretion (Goodman and Kruskal’s gamma coefficient: 0.72; p < 0.01). Mono Mac 6 cells revealed the highest fraction of differentially expressed genes, dominated by up-regulation of various cytokines and chemokines. BEAS-2B cells revealed weaker changes in a limited set of inflammatory response proteins. No significant changes were observed in Jurkat cells. Conclusions Monocytes are particularly responsive to indoor dust. We observed a classical T-helper 1-dominated immune response, which suggested that bioorganic contaminants are relevant effectors in indoor dust.

Effects of low-toxicity particulate matter on human nasal function.

Chronic nasal and paranasal sinus problems affect approximately 15% of the population in industrialized countries. Recent studies suggest that particulate matter might contribute to this condition. The effects of acute exposure to low-toxicity particulate matter on human nasal airflow, mucociliary transport, and nasal discomfort should be assessed. Thirty-two healthy volunteers were exposed to 0 (control), 500, 1000, and 5000 &mgr;g/m3 calcium carbonate dust for 3 hours and nasal saccharin transport time (STT), rhinomanometry, and visual analog scales (VAS) on nasal discomfort were obtained. A dose dependent decrease of STT (P = 0.02) and nasal patency (P = 0.04), and increased sensation of nasal obstruction (P = 0.002) and dryness (P = 0.03) was observed. The results indicate that acute exposure to low-toxicity particulate matter in concentrations frequently encountered in western agglomeration areas may affect nasal functions and cause nasal symptoms.

Centrosome abnormalities in head and neck squamous cell carcinoma (HNSCC)

Conclusions. Numerical and structural centrosome abnormalities play a critical role in the tumor progression of in head and neck squamous cell carcinoma (HNSCC) and may provide useful information as a prognostic factor for these patients. Objectives. Centrosome alterations are often linked with aneuploidy, cell transformation, and tumor progress. We investigated centrosome abnormalities in HNSCC and correlated these variables to clinicopathological parameters and clinical follow up data of the patients. Methods. Retrospective analysis of numerical and structural alterations of centrosomes in tumor tissues and corresponding normal epithelium (n=50 and 31, respectively). Immunohistochemistry was performed using an anti-γ-tubulin antibody. Image acquisition was done by an Orthoplan microscope, centrosomes were segmented interactively, and area as well as mean optical density was measured. Aneuploidy was evaluated by fluorescence in situ hybridization in a subset of cases (n=29). Results. Numerical and structural centrosome abnormalities differed significantly between normal squamous epithelium and tumor cells (both P<0.0001). Especially numerical centrosome abnormalities were significantly associated with T category and tumor stage (both P<0.0001) and the occurrence of distant metastasis (P=0.002 and P=0.019, respectively). Numerical centrosome abnormalities correlated also with disease free survival of the patients (P=0.032) as well as shorter overall survival (P=0.003).

Short-term exposure to urban dust alters the mediator release of human nasal mucosa.

Learning ObjectivesIdentify any changes in cytokine (mediator) concentrations in nasal secretions after healthy individuals were experimentally exposed to urban dust.Recall what connection there was, if any, between post-exposure cytokine levels in nasal secretions on the one hand and, on the other, counts of inflammatory cells and nasal symptoms.Report the investigators’ conclusions as to whether exposure to urban dust is a cause of persistent nasal inflammation and chronic airway disease. Thirty healthy volunteers were nasally exposed to control air and urban dust (SRM 1649a) in concentrations of 150 and 500 &mgr;g/m3 for 3 hours. Thirty minutes, 8 hours, and 24 hours after exposure, nasal cytologies were obtained, and nasal secretion levels of interleukin (IL)-1&bgr;, IL-6, IL-8, tumor necrosis factor-&agr;, epithelial neutrophil activating protein-78, monocyte chemoattractant protein-1, and substance P were determined. Twenty-four hours after exposure to 500 &mgr;g/m3, nasal secretion levels of IL-1&bgr; increased 72.3% (0–150.2%, P= 0.002), levels of IL-6 increased 42.2% (−28–161.9%,P = 0.01), and levels of IL-8 increased 19.7% (−20.3–60.5%, P = 0.03; median and 95% confidence interval). These cytokines correlated closely with nasal inflammatory cell counts. No exposure-related changes of tumor necrosis factor-&agr;, monocyte chemoattractant protein-1, epithelial neutrophil activating protein-78, and substance P levels were observed. These results provide experimental support for recent epidemiological observations that short-term increase of outdoor particulate matter concentration increases the frequency of upper respiratory diseases.