Alzheimer’s Disease (AD) is the most common cause of dementia, and its characteristic histopathological hallmarks are neurofibrillary tangles and senile plaques. Among involved mechanisms, oxidative stress plays an important role in damaging cell components (e.g., proteins, nucleic acids). In this study, different oxidized products of proteins and DNA were determined in the urine samples from mild cognitive impairment due to AD patients (n = 53) and healthy controls (n = 27) by means of ultra-performance liquid chromatography-tandem mass spectrometry analysis. A multivariate model developed by partial least squares generated a diagnostic model for AD with an AUC-ROC (area under the curve-receiver operating characteristic) of 0.843. From the studied analytes, 8-OHdG (8-hydroxy-2’-deoxyguanosine) and the ratio 8-OHdG/2dG (2’-deoxyguanosine) were able to distinguish between AD and healthy participants, showing statistically significant differences between groups, postulating DNA oxidation as a molecular pathway involved in early AD.

Alzheimer disease (AD) is an increasingly common neurodegenerative disease, especially in countries with aging populations. Its diagnosis is complex and is usually carried out in advanced stages of the disease. In addition, lipids and oxidative stress have been related to AD since the earliest stages. A diagnosis in the initial or preclinical stages of the disease could help in a more effective action of the treatments. Isoprostanoid biomarkers were determined in plasma samples from preclinical AD participants (n = 12) and healthy controls (n = 31) by chromatography and mass spectrometry (UPLC-MS/MS). Participants were accurately classified according to cerebrospinal fluid (CSF) biomarkers and neuropsychological examination. Isoprostanoid levels did not show differences between groups. However, some of them correlated with CSF biomarkers (t-tau, p-tau) and with cognitive decline. In addition, a panel including 10 biomarkers showed an area under curve (AUC) of 0.96 (0.903–1) and a validation AUC of 0.90 in preclinical AD prediction. Plasma isoprostanoids could be useful biomarkers in preclinical diagnosis for AD. However, these results would require a further validation with an external cohort.

Steroid hormones are biologically active factors in human milk (HM) that influence the physical and mental development of infants. Critically, maternal psychosocial stress has been associated with changes in HM steroid composition. This work aimed to characterize the steroid hormone profile of HM and pasteurized donor human milk (DHM) and assess the interplay between maternal physical and psychosocial status, the HM steroid profile, and infant outcomes. A targeted ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed to quantify sixteen steroid hormones in HM samples. HM samples from mothers of term infants (N = 42) and preterm infants (N = 35) were collected at (i) recovery of birth weight or achievement of complete enteral nutrition, respectively, and (ii) 6 months later as well as DHM samples (N = 19) from 11 donors. The physical and psychosocial status of mothers and infant neurodevelopment and temperament were assessed through structured interviews and validated questionnaires. Fourteen steroids were detected in HM/DHM samples, with cortisol, 20β-dihydrocortisol, dehydroepiandrosterone, pregnenolone, and cortisone being present in > 48% of samples. Pregnenolone, 17α-OH-progesterone, and dehydroepiandrosterone are reported for the first time in HM. Whereas milk cortisol levels were not directly related to maternal physical and psychosocial status nor with infant development, cortisone, and pregnenolone correlated positively with maternal weight gain during pregnancy and were associated with maternal well-being and infant growth. The pasteurization process may have a detrimental effect on the steroid hormone levels in HM, which might influence the development of receptors.

Previous studies showed a relationship between lipid oxidation biomarkers from plasma samples and Alzheimer’s Disease (AD), constituting a promising diagnostic tool. In this work we analyzed whether these plasma biomarkers could reflect specific brain oxidation in AD. In this work lipid peroxidation compounds were determined in plasma and cerebrospinal fluid (CSF) samples from AD and non-AD (including other neurological pathologies) participants, by means of an analytical method based on liquid chromatography coupled with mass spectrometry. Statistical analysis evaluated correlations between biological matrices. The results did not show satisfactory correlations between plasma and CSF samples for any of the studied lipid peroxidation biomarkers (isoprostanes, neuroprostanes, prostaglandines, dihomo-isoprostanes). However, some of the analytes showed correlations with specific CSF biomarkers for AD and with neuropsychological tests (Mini-Mental State Examination (MMSE), Repeatable Battery for the Assessment of Neuropsychological Status (RBANS)). In conclusion, lipid peroxidation biomarkers in CSF samples do not reflect their levels in plasma samples, and no significant differences were observed between participant groups. However, some of the analytes could be useful as cognitive decline biomarkers.

Purpose: Quizartinib pharmacokinetics in FLT3-ITD negative acute myeloid leukemia (AML) remain largely unexplored. This study aims to validate a population pharmacokinetics model (popPK) for quizartinib in plasma samples of FLT3-ITD negative AML patients. To do so, an ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) method has been developed and validated for the quantification of quizartinib. Methods: Plasma samples were collected from FLT3-ITD negative newly diagnosed AML patients undergoing quizartinib therapy at induction in the QUIWI phase II clinical trial [NCT04107727, PETHEMA group] between March 2020 and February 2022. The UPLC-MS/MS method was developed and validated. A previously described popPK model was validated using external validation techniques and implemented using the software NONMEM v7.5. Results: The developed UPLC-MS/MS method demonstrated high accuracy and precision with a linear range of 6 to 200 ng/mL, with relative standard deviation between 3–11 and accuracy of 88–97% from nominal values. The external validation of the quizartinib popPK model showed minimal bias at the population level (MdPE: -9.86%; ME: 0.50 ng/mL, p = 0.964), but moderate imprecision (MdAPE: 32.28%) and suboptimal accuracy (F20: 24.5%; F30: 43.4%). Individual predictions improved performance, with negligible bias (MdPE: -0.50%), acceptable precision (MdAPE: 11.27%), and F20 (64.2%) and F30 (77.4%) exceeding predefined thresholds. Visual predictive checks confirmed adequate prediction of median concentrations, though some deviations occurred at extremes. Conclusion: This study presents a replicable UPLC-MS/MS method for the determination of quizartinib in plasma. The validated popPK model can be used to optimize dosing strategies in future clinical studies.

Background and Aims: Cyclooxygenase‐2 (COX‐2) is involved in different liver diseases, but little is known about the significance of COX‐2 in cholestatic injury. This study was designed to elucidate the role of COX‐2 expression in hepatocytes during the pathogenesis of obstructive cholestasis.Methods: We used genetically modified mice constitutively expressing human COX‐2 in hepatocytes. Transgenic mice (hCOX‐2‐Tg) and their wild‐type (Wt) littermates were either subjected to a mid‐abdominal laparotomy or common bile duct ligation (BDL) for 2 or 5 days. Then, we explored the mechanisms underlying the role of COX‐2 and its derived prostaglandins in liver function, and the synthesis and excretion of bile acids (BA) in response to cholestatic liver injury.Results: After BDL, hCOX‐2‐Tg mice showed lower grades of hepatic necrosis and inflammation than Wt mice, in part by a reduced hepatic neutrophil recruitment associated with lower mRNA levels of pro‐inflammatory cytokines. Furthermore, hCOX‐2‐Tg mice displayed a differential metabolic pattern of BA synthesis that led to an improved clearance after BDL‐induced accumulation. In addition, an enhanced response to the BDL‐induced oxidative stress and hepatic apoptosis was observed. In vitro experiments using hepatic cells that stably express hCOX‐2 confirmed the cytoprotective role of prostaglandin E₂ against BA toxicity.Conclusions: Taken together, our data indicate that constitutive expression of COX‐2 in hepatocytes ameliorates cholestatic liver injury in mice by reducing inflammation and cell damage and by modulating BA metabolism, pointing to a role for COX‐2 as a defensive response against cholestasis‐derived BA accumulation and injury.