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Aim: To retrospectively compare two approaches for the adjunctive use of systemic antibiotics in non-surgical periodontal therapy: one based on the detection of Aggregatibacter actinomycetemcomitans (Aa) and the other on age and severity of periodontitis (Age & PPD). We also assessed the additional benefit of antibiotics in reducing the need for further surgical therapy in each group., Materials and Methods: Patients of the Department of Periodontology, Goethe University Frankfurt, Germany, were screened for microbiological testing between 2008 and 2018. Patients were categorized by their microbiological result (Aa+/-) and demographic/clinical data (Age & PPD+/-). Agreement on antibiotic indication was tested. The clinical evaluation focussed on teeth with probing pocket depths (PPDs) ≥ 6 mm., Results: Analysis of 425 patients revealed 30% categorized as Age & PPD+ and 34% as Aa+. Sixty-three percent had consistent antibiotic recommendations (phi coefficient 0.14, p = .004). Patients in the Age & PPD+ group receiving antibiotics showed the most substantial reduction in the number of teeth with PPD ≥ 6 mm after non-surgical periodontal therapy., Conclusions: Both strategies resulted in a significant clinical improvement compared with those without antibiotic treatment and restricted antibiotic use similarly, but targeted different patient groups. Younger individuals with severe periodontitis benefited most from antibiotics, reducing the need for additional surgeries. The study was registered in an international trial register (German Clinical Trial Register number DRKS00028768, registration date 27 April 2022, https://drks.de/search/en/trial/DRKS00028768)., (© 2024 The Author(s). Journal of Clinical Periodontology published by John Wiley & Sons Ltd.)

This randomized, double-blind, cross-over study assessed the comparative pharmacokinetics of steviol and steviol glucuronide following single oral doses of rebaudioside A and stevioside in healthy adult male subjects. Steviol glucuronide appeared in the plasma of all subjects after administration of rebaudioside A or stevioside, with median tmax values of 12.0 and 8.00h post-dose, respectively. Steviol glucuronide was eliminated from the plasma, with similar t1/2 values of approximately 14h for both compounds. Administration of rebaudioside A resulted in a significantly (approximately 22%) lower steviol glucuronide geometric mean Cmax value (1472ng/mL) than administration of stevioside (1886ng/mL). The geometric mean AUC0-t value for steviol glucuronide after administration of rebaudioside A (30,788ngh/mL) was approximately 10% lower than after administration of stevioside (34,090ngh/mL). Steviol glucuronide was excreted primarily in the urine of the subjects during the 72h collection period, accounting for 59% and 62% of the rebaudioside A and stevioside doses, respectively. No steviol glucuronide was detected in feces. Pharmacokinetic analysis indicated that rebaudioside A and stevioside underwent similar metabolic and elimination pathways in humans with steviol glucuronide excreted primarily in the urine and steviol in the feces. No safety concerns were noted as determined by reporting of adverse events, laboratory assessments of safety or vital signs.

Methyl-substituted psoralens (4'-(hydroxymethyl)-4,5',8-trimethylpsoralen and 4,5',8-trimethylpsoralen) are found to yield an ene product as well as the expected [2 + 2] cycloaddition product from photochemical reaction with simple olefins. As determined by absorbance, liquid chromatography-mass spectrometry and nuclear magnetic resonance, both products are formed at the pyrone side of the respective psoralen. The product distribution is dependent on olefin concentration as well as the nature of the olefin. In deoxygenated solutions, cyclic olefins form as much as 50% ene product, while unsubstituted straight-chain olefins form as little as 3%. In oxygenated solutions, the product distribution is strongly affected by singlet oxygen.

A particle beam interface has been coupled to a quadrupole ion trap mass spectrometer. The system allows the collection of electron ionization mass spectra from analyte in solution. The interface incorporates a pneumatic nebulizer, a heated desolvation chamber, and a three-stage separator region. Additional helium, for improved performance, is added through stage 3. The particles formed in the interface are separated from solvent molecules and are transferred directly to the ion trap where they are expected to collide with the hot hyperbolic surface of the end cap. The end cap serves both as a heated target used to vaporize the particles and as an ion-trapping electrode. Mass analysis is achieved with the mass-selective instability scan supplemented with resonance ejection. Electron ionization spectra from 100 ng of caffeine [molecular weight (MW) = 1941; 1-naphthalenol methylcarbamate (carbaryl) (MW = 2011, 17α-hydroxyprogesterone (MW = 330), and reserpine (MW = 608) are shown using sampling by a segmented flow analysis. Some charge exchange is evident with methanol as well as self-chemical ionization at higher analyte levels. The interface shows a nonlinear caffeine calibration curve for analyte amounts below 30 ng and a more linear response at higher amounts. Caffeine was detected at 25 pmol (5 ng), with a signal-to-noise ratio of 50, 20-μL loop, full scan.