Early Mechanistic Events Induced by Low Molecular Weight Polycyclic Aromatic Hydrocarbons in Mouse Lung Epithelial Cells: A Role for Eicosanoid Signaling

Low molecular weight polycyclic aromatic hydrocarbons (LMW PAHs; < 206.3 g/mol) are under regulated environmental contaminants (eg, secondhand smoke) that lead to gap junction dysregulation, p38 MAPK activation, and increased mRNA production of inflammatory mediators, such as cytokines and cyclooxygenase (COX2), in lung epithelial cells. However, the early mechanisms involving lipid signaling through the arachidonic acid pathway and subsequent eicosanoid production leading to these downstream events are not known. Common human exposures are to mixtures of LMW PAHs, thus C10 cells (a mouse lung epithelial cell line) were exposed to a representative binary PAH mixture, 1-methylanthracene (1-MeA) and fluoranthene (Flthn), for 30 min-24 h with and without p38 and cytosolic phospholipase A2 (cPLA2) inhibitors. Cytosolic phospholipase A2 inhibition reversed PAH-induced phospho-p38 MAPK activation and gap junction dysregulation at 30 min. A significant biphasic increase in cPLA2 protein was observed at 30 min, 2, and 4 h, as well as COX2 protein at 2 and 8 h. Untargeted metabolomics demonstrated a similar trend with significantly changing metabolites at 30 min and 4 h of exposure relative to 1 h; a "cPLA2-like" subset of metabolites within the biphasic response were predominately phospholipids. Targeted metabolomics showed several eicosanoids (eg, prostaglandin D2 (PGD2), PGE2α) were significantly increased at 4, 8, and 12 h following exposure to the binary PAH mixture and this effect was p38-dependent. Finally, PAH metabolism was not observed until after 8 h. These results indicate an early lipid signaling mechanism of LMW PAH toxicity in lung epithelial cells due to parent PAH compounds.

Antipseudomonal activity enhancement of luminescent iridium(iii) dipyridylamine complexes under visible blue light

Cyclometallated iridium(iii) dipyridylamine complexes present antibacterial activity against P. aeruginosa, a highly resistant pathogenic bacterium. This activity is increased when the complex is conjugated to biotin, a bacterial nutrient, and a MIC of 4 μM (4 μg mL^-1) has been observed. The irradiation of P. aeruginosa cultures with blue LED light potentiates the anti-bacterial activities of these iridium(iii) complexes when they are conjugated to a glycoside.

Determining the presence of asthma-related molecules and salivary contamination in exhaled breath condensate

Background

Researchers investigating lung diseases, such as asthma, have questioned whether certain compounds previously reported in exhaled breath condensate (EBC) originate from saliva contamination. Moreover, despite its increasing use in ‘omics profiling studies, the constituents of EBC remain largely uncharacterized. The present study aims to define the usefulness of EBC in investigating lung disease by comparing EBC, saliva, and saliva-contaminated EBC using targeted and untargeted mass spectrometry and the potential of metabolite loss from adsorption to EBC sample collection tubes.

Methods

Liquid chromatography mass spectrometry (LC-MS) was used to analyze samples from 133 individuals from three different cohorts. Levels of amino acids and eicosanoids, two classes of molecules previously reported in EBC and saliva, were measured using targeted LC-MS. Cohort 1 was used to examine contamination of EBC by saliva. Samples from Cohort 1 consisted of clean EBC, saliva-contaminated EBC, and clean saliva from 13 healthy volunteers; samples were analyzed using untargeted LC-MS. Cohort 2 was used to compare eicosanoid levels from matched EBC and saliva collected from 107 asthmatic subjects. Samples were analyzed using both targeted and untargeted LC-MS. Cohort 3 samples consisted of clean-EBC collected from 13 subjects, including smokers and non-smokers, and were used to independently confirm findings; samples were analyzed using targeted LC-MS, untargeted LC-MS, and proteomics. In addition to human samples, an in-house developed nebulizing system was used to determine the potential for EBC samples to be contaminated by saliva.

Results

Out of the 400 metabolites detected in both EBC and saliva, 77 were specific to EBC; however, EBC samples were concentrated 20-fold to achieve this level of sensitivity. Amino acid concentrations ranged from 196 pg/mL – 4 μg/mL (clean EBC), 1.98 ng/mL – 6 μg/mL (saliva-contaminated EBC), and 13.84 ng/mL – 1256 mg/mL (saliva). Eicosanoid concentration ranges were an order of magnitude lower; 10 pg/mL – 76.5 ng/mL (clean EBC), 10 pg/mL – 898 ng/mL (saliva-contaminated EBC), and 2.54 ng/mL – 272.9 mg/mL (saliva). Although the sample size of the replication cohort (Cohort 3) did not allow for statistical comparisons, two proteins and 19 eicosanoids were detected in smoker vs. non-smoker clean-EBC.

Conclusions

We conclude that metabolites are present and detectable in EBC using LC-MS; however, a large starting volume of sample is required.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-017-0538-5) contains supplementary material, which is available to authorized users.

Basics in canine and feline rhinoscopy

Patients suffering from upper respiratory disease such as chronic nasal congestion, sneezing, nasal discharge, and epistaxis invite complete evaluation of their paired nasal cavities. Thorough assessment of these cavities employs sundry diagnostic procedures that enable the investigating clinician to characterize the internal structures of the nasal cavities. After the conscious patient undergoes a complete physical examination, a gross assessment of its external nasal structures is established and areas of physical asymmetry are noted. A working anatomic knowledge of these asymmetric foci helps to guide the next diagnostic steps. The patient is then placed under general anesthesia, during which, in list order, imaging studies, rhinoscopy, and nasal biopsy or foreign body retrieval, are performed.

Use of medications with anticholinergic effect predicts clinical severity of delirium symptoms in older medical inpatients

BACKGROUND

Use of anticholinergic (ACH) medications is a biologically plausible and potentially modifiable risk factor of delirium, but research findings are conflicting regarding its association with delirium.

OBJECTIVES

To evaluate the longitudinal association between use of ACH medications and severity of delirium symptoms and to determine whether this association is modified by the presence of dementia.

PATIENTS AND METHODS

A total of 278 medical inpatients 65 years and older with diagnosed incident or prevalent delirium were followed up with repeated assessments using the Delirium Index for up to 3 weeks. Exposure to ACH and other medications was measured daily. The association between change in medication exposure in the 24 hours preceding a Delirium Index assessment was assessed using a mixed linear regression model.

RESULTS

During follow-up (mean +/- SD, 12.3 +/- 7.0 days), 47 medications with potential ACH effect were used in the population (mean, 1.4 medications per patient per day). Increase in delirium severity was significantly associated with several measures of ACH medication exposure on the previous day, adjusting for dementia, baseline delirium severity, length of follow-up, and number of non-ACH medications taken. Dementia did not modify the association between ACH medication use and delirium severity.

CONCLUSION

Exposure to ACH medications is independently and specifically associated with a subsequent increase in delirium symptom severity in elderly medical inpatients with diagnosed delirium.

Prevalence and detection of delirium in elderly emergency department patients

BACKGROUND

Delirium is a complex medical disorder associated with high morbidity and mortality among elderly patients. The goals of our study were to determine the prevalence of delirium in emergency department (ED) patients aged 65 years and over and to determine the sensitivity and specificity of a conventional clinical assessment by an ED physician for the detection of delirium in the same population.

METHODS

All elderly patients presenting to the ED in a primary acute care, university-affiliated hospital who were triaged to the observation room on a stretcher because of the severity of their illness were screened for delirium by a research psychiatrist using the Mini-Mental State Examination and the Confusion Assessment Method. The diagnosis of "delirium" or an equivalent term by the ED physician was determined by 2 methods: completion of a mental status checklist by the ED physician and chart review. The prevalence of delirium and the sensitivity and specificity of the ED physician's clinical assessment were calculated with their 95% confidence intervals. The demographic and clinical characteristics of patients with detected delirium and those with undetected delirium were compared.

RESULTS

A sample of 447 patients was screened. The prevalence of delirium was 9.6% (95% confidence interval 6.9%-12.4%). The sensitivity of the detection of delirium by the ED physician was 35.3% and the specificity, 98.5%. Most patients with delirium had neurologic or pulmonary diseases, and most patients with detected delirium had neurologic diseases.

INTERPRETATION

Despite the relatively high prevalence of delirium in elderly ED patients, the sensitivity of a conventional clinical assessment for this condition is low. There is a need to improve the detection of delirium by ED physicians.

Delirium risk factors in elderly hospitalized patients

OBJECTIVE

Delirium is frequent in elderly hospitalized patients. Many studies have examined its risk factors, but results have been quite variable. Thus, the goal of this study is to identify through systematic literature review the risk factors associated with the development of delirium in hospitalized geriatric patients.

MEASUREMENTS AND MAIN RESULTS

First, MEDLINE/CURRENT CONTENTS databases were screened for relevant articles published from 1966 to December 1995, and from bibliographies of identified articles additional reports were selected. Second, the reports were screened by two different investigators and retained only if meeting the five following criteria: (1) original research in French or English; (2) prospective study; (3) patients over age 50; (4) minimum of one risk factor examined; (5) acceptable definition of delirium. Third, the methodology of each study was graded according to specific criteria for risk factor studies. Fourth, risk factors were identified and tabulated, unadjusted odds ratios (ORs) were computed, and where appropriate a combined OR with the Mantel-Haenszel estimator was calculated. Twenty-seven articles were retained meeting all of the above criteria. Among these studies, 11 were done on medical patients, 9 on surgical patients, 2 on medical and surgical patients, and 5 on psychiatric patients. In total 1,365 subjects with delirium were studied. Sixty-one different risk factors were examined, the five most common being dementia, medication, medical illness, age, and male gender. Mantel-Haenszel estimator was calculated for 10 risk factors, the most strongly associated being dementia (OR 5.2; 95% confidence interval [CI] 4.2, 6.3), medical illness (OR 3.8; 95% CI 2.2, 6.4), alcohol abuse (OR 3.3; 95% CI 1.9, 5.5), and depression (OR 1.9; 95% CI 1.3, 2.6). Methodologic weaknesses were present in many studies.

CONCLUSIONS

Despite methodologic limitations, certain risk factors for delirium seem to be consistent and could help identify high-risk patients. These risk factors include dementia, advanced age, and medical illness. Other risk factors appear to play a contributory role in the development of delirium in elderly hospitalized patients.

Chronic subdural hematoma in the elderly: a case report

A previously healthy 82-year-old male presented with depressive and paranoid symptoms of 3 months' duration. Physical examination and cognitive functions were normal. Poor response to treatment and continuing weight loss lead to medical investigations that ultimately showed a large, left frontoparietal, chronic subdural hematoma. Following drainage, the patient showed some improvement in paranoid features but still required pharmacologic treatment for depression. The psychiatric features of chronic subdural hematoma as well as the management of this neurologic condition in the elderly patient are reviewed and discussed.

Canine immune-mediated diabetes mellitus: a case report

A four-year-old, spayed female toy fox terrier presented with hyperglycemia and severe anemia. A diagnosis of immune-mediated diabetes mellitus was made based upon the finding of beta-cell specific antibodies. Immune-mediated hemolytic anemia was diagnosed based on findings of a regenerative anemia, spherocytosis, hyperbilirubinemia, hemoglobinuria, and bilirubinuria. The anemia resolved following two months of immunosuppressive therapy. The diabetes was treated with insulin for four months, after which time treatment was no longer necessary. However, the dog remained positive for beta-cell antibodies which may be a predictive marker for the recurrence of diabetes mellitus in the future.