Cancer evaluation in dogs using cerumen as a source for volatile biomarker prospection

Cancer is one of the deadliest diseases in humans and dogs. Nevertheless, most tumor types spread faster in canines, and early cancer detection methods are necessary to enhance animal survival. Here, cerumen (earwax) was tested as a source of potential biomarkers for cancer evaluation in dogs. Earwax samples from dogs were collected from tumor-bearing and clinically healthy dogs, followed by Headspace/Gas Chromatography-Mass Spectrometry (HS/GC-MS) analyses and multivariate statistical workflow. An evolutionary-based multivariate algorithm selected 18 out of 128 volatile metabolites as a potential cancer biomarker panel in dogs. The candidate biomarkers showed a full discrimination pattern between tumor-bearing dogs and cancer-free canines with high accuracy in the test dataset: an accuracy of 95.0% (75.1-99.9), and sensitivity and specificity of 100.0% and 92.9%, respectively. In summary, this work raises a new perspective on cancer diagnosis in dogs, being carried out painlessly and non-invasive, facilitating sample collection and periodic application in a veterinary routine.

A volatolomic approach using cerumen as biofluid to diagnose bovine intoxication by Stryphnodendron rotundifolium

An innovative volatolomic approach employs the detection of biomarkers present in cerumen (earwax) to identify cattle intoxication by Stryphnodendron rotundifolium Mart., Fabaceae (popularly known as barbatimão). S. rotundifolium is a poisonous plant with the toxic compound undefined and widely distributed throughout the Brazilian territory. Cerumen samples from cattle of two local Brazilian breeds ('Curraleiro Pé-Duro' and 'Pantaneiro') were collected during an experimental intoxication protocol and analyzed using headspace (HS)/GC-MS followed by multivariate analysis (genetic algorithm for a partial least squares, cluster analysis, and classification and regression trees). A total of 106 volatile organic metabolites were identified in the cerumen samples of bovines. The intoxication by S. rotundifolium influenced the cerumen volatolomic profile of the bovines throughout the intoxication protocol. In this way, it was possible to detect biomarkers for cattle intoxication. Among the biomarkers, 2-octyldecanol and 9-tetradecen-1-ol were able to discriminate all samples between intoxicated and nonintoxicated bovines. The cattle intoxication diagnosis by S. rotundifolium was accomplished by applying the cerumen analysis using HS/GC-MS, in an easy, accurate, and noninvasive way. Thus, the proposed bioanalytical chromatography protocol is a useful tool in veterinary applications to determine this kind of intoxication.

Lichen planus: altered AIM2 and NLRP1 expression in skin lesions and defective activation in peripheral blood mononuclear cells

BACKGROUND

Lichen planus (LP) is an inflammatory skin disease with unknown aetiology. Activation by pathogen-associated molecular patterns or environmental stimuli may activate some components of inflammasomes that contribute to the inflammatory process in LP lesions.

AIM

To characterize the inflammasomes in skin lesions and peripheral blood mononuclear cells (PBMCs) of patients with LP under Toll-like receptor (TLR) activation.

METHODS

In total, 15 patients with LP and 14 healthy controls (HCs) were enrolled in the study. Inflammasome expression in skin was evaluated by real-time PCR and immunohistochemistry, while ELISA was used to assess the production of interleukin (IL)-1β by PBMCs under stimulation with TLR4 and TLR7/TLR8 agonists and adenosine triphosphate (ATP).

RESULTS

Compared with the levels in HC samples, increased expression of the inflammasome AIM2 was verified in both epidermal and dermal sections of LP skin lesions, whereas NLRP1 and IL-β expression levels were enhanced in the dermis. LP skin lesion samples exhibited higher AIM2 transcript levels, similar NLRP1 levels and lower pro-IL-1β mRNA levels compared with HC samples. We verified that, compared with PBMCs from HC subjects, PBMCs from patients with LP produced similar amounts of IL-1β after induction by TLR4 agonists but lower IL-1β levels after induction by TLR7/TLR8 agonists, regardless of the addition of ATP.

CONCLUSION

Alterations in innate immunity, such as inflammasome component expression in skin lesions and PBMCs, were observed in patients with LP. Further investigations of dysfunctional inflammasome activation and the chronic inflammatory status of LP are required.