Using the modified Schirmer test for dry mouth assessment: A cross-sectional study

This study aimed to establish whether the modified Schirmer test could serve as a diagnostic tool for dry mouth, that is, whether it could reliably measure salivary film at selected locations within the oral cavity, and to identify levels of sensitivity/specificity and determine reference values. Therefore, a cross-sectional study (N = 120, mean age 63.5 [SD 13.9] years) was performed. The test was used at five locations (hard palate; buccal mucosa in molar region at 4 mm above occlusal plane; anterior tongue; lower lip; mouth floor), and results were recorded after 1, 2 and 3 min. A statistically significant discriminatory ability of the Schirmer test for the unstimulated salivary flow rates could be shown for the palate (at 3 min), buccal mucosa (at 1 min), mouth floor (at 1 min), and tongue (at 2 and 3 min) (areas under the curve 0.64-0.68), with individual sensitivity/specificity values depending on test location/time points. Thus, the modified Schirmer test has potential to become a simple and reproducible instrument for the detection of dry mouth based on low unstimulated salivary flow rates in dentistry and especially outreach care. Care must be taken concerning intraoral test location and measurement time.

Defensive production of formic acid (80%) by a carabid beetle (Galerita lecontei)

The carabid beetle Galerita lecontei has a pair of abdominal defensive glands that secrete a mixture of formic acid, acetic acid, and lipophilic components (long-chain hydrocarbons and esters). Formic acid, at the concentration of 80%, is the principal constituent. The beetle ejects the secretion as a spray, which it aims accurately toward parts of the body subjected to assault. At full capacity, the glands store 4.5 mg of formic acid (3% of body mass), enough for upward of six ejections. The beetle reloads the glands at a rate of 126 microg of formic acid per day. For the approximately 500 secretory cells of the glands, this means an hourly output of 10 ng of formic acid per cell, or about 5% of cell volume. Replenishing empty glands to their full formic acid load takes the beetle an estimated 37 days. Replenishing the 0.7 mg of formic acid expended in a single discharge takes 5.5 days.