Investigation of salivary biomarkers as indicators of skeletal and dental maturity in children.

OBJECTIVE: Estimation of patient's skeletal maturity in orthodontics is essential for the diagnosis and treatment planning. The aim of the study was to investigate the potential use of metabolic fingerprint of saliva for bone growth and tooth development estimation. MATERIALS AND METHODS: Saliva samples from 54 young patients were analysed by an untargeted gas chromatography-mass spectrometry metabolomics-based method. The skeletal maturity was calculated with the cervical vertebrae maturation method, and the dental age was estimated with the Demirjian method. Multivariate analysis and univariate analysis were performed to investigate differences within skeletal, dental and chronological age groups. RESULTS: Metabolomic analysis identified 61 endogenous compounds. Mannose, glucose, glycerol, glyceric acid and pyroglutamic acid levels differentiated significantly with skeletal age (P = .02 to .043), while mannose, lactic acid, glycolic acid, proline, norleucine, 3-aminoisobutyric acid, threonine, cadaverine and hydrocinnamic acid levels differed within the dental age groups (P = .018 to .04); according to the chronological age, only the levels of mannose and 3-hydroxyphenylacetic acid showed variation (P = .029 and .048). The principal component analysis did not manage to highlight differences between the groups of the studied parameters. CONCLUSION: Differentiated levels of mannose, glucose, glycerol, glyceric acid and pyroglutamic acid related to skeletal maturation were identified. According to dental development, the levels of mannose, lactic acid, glycolic acid, proline, norleucine, 3-aminoisobutyric acid, threonine, cadaverine and hydrocinnamic acid differed within the groups, while regarding chronological age, only the levels of mannose and 3-hydroxyphenylacetic acid showed variations. Further studies are required to prove their relation to skeletal and dental development pathway by applying complementary analytical techniques to wider cover the metabolome.

Evaluation of Cocaine Effect on Endogenous Metabolites of HepG2 Cells Using Targeted Metabolomics.

Cocaine toxicity has been a subject of study because cocaine is one of the most common and potent drugs of abuse. In the current study the effect of cocaine on human liver cancer cell line (HepG2) was assessed. Cocaine toxicity (IC50) on HepG2 cells was experimentally calculated using an XTT assay at 2.428 mM. The metabolic profile of HepG2 cells was further evaluated to investigate the cytotoxic activity of cocaine at 2 mM at three different time points. Cell medium and intracellular material samples were analyzed with a validated HILIC-MS/MS method for targeted metabolomics on an ACQUITY Amide column in gradient mode with detection on a triple quadrupole mass spectrometer in multiple reaction monitoring. About 106 hydrophilic metabolites from different metabolic pathways were monitored. Multivariate analysis clearly separated the studied groups (cocaine-treated and control samples) and revealed potential biomarkers in the extracellular and intracellular samples. A predominant effect of cocaine administration on alanine, aspartate, and glutamate metabolic pathway was observed. Moreover, taurine and hypotaurine metabolism were found to be affected in cocaine-treated cells. Targeted metabolomics managed to reveal metabolic changes upon cocaine administration, however deciphering the exact cocaine cytotoxic mechanism is still challenging.

Α Simple Method for the Determination of Lacosamide in Blood by GC-MS.

Lacosamide is a functionalized amino acid with antiepileptic function. Therapeutic drug monitoring (TDM) in patients for lacosamide is critical as it allows clinicians to control epileptic seizures. A single liquid-liquid extraction step was applied for the extraction of lacosamide from whole blood samples which were thereafter analyzed by GC-MS. Optimum extraction conditions were selected on the basis of experiments with various solvents at different pHs, indicating ethyl acetate at pH 12 as the most efficient parameters for the extraction of lacosamide. Method exhibited linearity from 2 to 100 µg/mL with R2  = 0.998. Accuracy and precision were evaluated at three concentrations and found to be within acceptable limits. LOD and LOQ were determined at 0.1 and 0.5 µg/mL, respectively. Lacosamide was found to be stable at storage conditions. The developed method was applied successfully in clinical samples and postmortem blood sample from an overdose case.

Determination of drugs of abuse and pharmaceuticals in skeletal tissue by UHPLC-MS/MS.

In several medico legal cases bone analysis may provide the only source of toxicological information. The present study reports the development of an UHPLC-MS/MS method for the detection and quantification of 27 drugs and pharmaceuticals in human bones. The target compounds comprise pharmaceuticals (antipsychotics and antidepressants) and some of the most important groups of drugs of abuse: opiates, cocaine, cannabinoids, amphetamines and benzodiazepines. Sample pretreatment was studied and the best results were obtained after extraction with methanol, stirring and ultra-sonication. The extract, after filtration, evaporation and reconstitution was analysed on a reversed-phase column (C18) in gradient elution over 17min. The method was found to be selective, and sensitive offering limits of detection (LOD) from 0.03 to 1.35ng/g of bone. Validation included evaluation of limit of quantification (LOQ), recovery, carry-over, matrix effect, accuracy and precision (RSD%) of the method. The method performed satisfactory in relation to established bioanalytical criteria and was therefore applied to the analysis of bone and bone marrow obtained post-mortem from chronic drug abusers, offering unambiguous identification and quantitative determination of drugs in bones from legal cases where the analysis of blood was not feasible.